Rehabilitation

 

 

Gait, Amputations, Prostheses, Orthoses, and Neurologic Injury

 

 

Section 1Gait,

Walking,

Gait Dynamics,

Determinants of Gait (Motion Patterns), Muscle Action,

Pathologic Gait,

Section 2Amputations,

Introduction,

Metabolic Cost of Amputee Gait, Load Transfer,

Amputation Wound Healing, Pediatric Amputation, Amputation After Trauma, Risk Factors, Musculoskeletal Tumors, Technical Considerations, Complications,

Upper Limb Amputations, Lower Limb Amputations,

Section 3Prostheses,

Upper Limb, Lower Limb,

Section 4Orthoses,

Introduction,

Shoes,

Foot Orthoses,

Ankle-Foot Orthoses, Knee-Ankle-Foot Orthosis,

Hip-Knee-Ankle-Foot Orthosis, Elbow Orthosis,

Wrist-Hand Orthosis, Fracture Braces, Pediatric Orthoses, Spine Orthoses,

Section 5Surgery for Stroke and Closed-Head Injury, Introduction,

Lower Limb, Upper Limb,

Section 6Postpolio Syndrome, Cause,

Treatment, Testable Concepts,

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Section 1 Gait Walking

• Definitions

  • Walking describes an energy-efficient process of controlled, reciprocal lower limb movements, used to move the body from one location to another while maintaining upright stability.

  • During walking the motion of the two legs is coordinated so that one supporting foot is in contact with the ground at all times (single-limb support), with a period when both limbs are in contact with the ground (double-limb stance support) (Fig. 10.1).

  • A step is the distance between successive initial contact by the two lower limbs.

  • Stride is the distance between successive initial contact by the same lower limb. (Fig. 10.2).

  • Velocity is the ratio of distance to time. Cadence defines steps per unit of time.

  • Running differs from walking in that it precludes double-limb support/stance.

• Phases: normal gait cycle is divided into stance and swing phases (see Fig. 10.1).

 

 

 

FIG. 10.1 Subdivisions of gait and their relationships to the pattern of bilateral floor contact. Adapted from Perry J: Gait analysis: normal and pathological function, New York, 1992, Slack Inc.

 

 

FIG. 10.2 Step versus stride.

Adapted from Perry J: Gait analysis: normal and pathological function, New York, 1992, Slack Inc.

 

• Stance phase occupies 60% of the gait cycle.

  • Initial contact (IC): the instant the reference foot contacts the ground

  • Loading response (LR) starts with initial contact of reference foot and ends with initial swing of the contralateral foot.

  • Midstance (MSt) begins with initial swing (ISw) of the advancing foot and ends when the body’s center of gravity is directly over the supporting forefoot.

  • Terminal stance (TSt) begins with heel rise and continues until initial contact of the contralateral (advancing) foot.

  • Preswing (PSw) begins with initial contact of contralateral limb and ends when the stance foot lifts off the ground.

• Swing phase is 40% of the gait cycle.

  • Initial swing (ISw) begins when the reference foot leaves the ground, and ends when the swinging foot is opposite the stance foot.

  • Midswing (MSw) ends when the swinging limb is forward with the tibia perpendicular/vertical to ground.

  • Terminal swing (TSw) spans the period from when the advancing limb’s tibia is perpendicular/vertical to ground to when the foot makes initial contact with the ground (Fig. 10.3).

• Important characteristics of gait cycle

  • Normal gait cycle requires stance-phase stability, swing-phase ground clearance, correct position of the foot before initial contact, and energy-efficient step length and speed.

  • There are two periods of double-limb support (during IC + LR and then PSw) ranging between 20% and 30% of the gait cycle. Time spent in these events is velocity dependent.

  • During normal walking, the body’s center of gravity is subject to vertical and lateral displacement. Minimizing trunk displacement decreases energy expenditure during bipedal

    gait.

    • In the sagittal plane of the body, vertical displacement follows a sinusoidal curve with an amplitude of 5 cm.

    • Lateral displacement also follows a sinusoidal curve, with an amplitude of 6 cm.

 

Gait Dynamics (Fig. 10.4)

• The combined phases of gait contribute to an energy-efficient process by lessening excursion of the center of body mass.

• Head, neck, trunk, and arms account for 70% of body weight.

• The trunk’s center of gravity is located just anterior to T10, 33 cm above the hip joints in an average-height (184 cm) individual.

• The entire body’s center of mass is 2 cm anterior to S2 and provides a reference for the moment arm to the center of the joint under consideration. The resulting gait pattern resembles a sinusoidal curve.

• The ground reaction force (GRF) is the mean loading-bearing vector, which changes in both magnitude and direction throughout the gait cycle. Understanding its dynamic relationship with and through a given joint is crucial to understanding muscle action across the joint in question as well as for the ensemble locomotor strategy (muscle action at other joints). The GRF also determines the rotational potential, known as moment or torque, that combined forces may exert on a joint.

   

  Determinants of Gait (Motion Patterns)

• Six principal processes have been identified as determinants of gait efficiency, working in concert to minimize vertical and lateral displacements of the center of mass during typical walking. Three occur at the pelvis, and the others involve the knee, ankle, and foot mechanisms.

  • Pelvic rotation: During forward motion, the pelvis externally rotates from IC to onset of PSw, and internally during PSw and swing. This symmetric net rotation minimizes the total vertical plane displacement needed for limb retraction and advancement in swing and stance.

     

     

     

     

    FIG. 10.3 Dimensions of the walking cycle: distance (A) and time (duration) (B).

    From Inman VT et al: Human walking, Baltimore, 1982, Williams & Wilkins, p 26.

     

  • Pelvic list (tilt): non–weight-bearing contralateral side drops 5 degrees, reducing superior deviation.

  • Knee flexion at loading (early knee flexion): stance-phase limb is flexed 15 degrees to dampen the impact of initial loading.

  • Foot and ankle motion: through subtalar joint, damping of loading response occurs, leading to stability during midstance and efficiency of propulsion at push-off.

  • Knee motion: knee works in concert with foot and ankle to decrease unnecessary limb motion. The knee flexes at IC and extends at midstance.

  • Control of pelvic lateral displacement: occurs during weight transfer of body onto the accepting/leading limb. Length of motion is 5 cm over the weight-bearing limb, narrowing the base of support and increasing stance-phase stability.

     

    FIG. 10.4 Kinetics and kinematics of gait cycle. The curves describe the hip, knee, and ankle joint positions through the gait cycle. The bars above and below the curves highlight the muscle actions across different phases. The red portions of the curves indicate the phases when ground reaction force is located anterior to the hip, posterior to knee, and anterior to the ankle, respectively, in the stance phase.

     

    Muscle Action (see Fig. 10.4)

• Agonist and antagonist muscle groups work in concert during the gait cycle to effectively advance the limb through space.

• Most muscle activity is eccentric, during which a muscle is active while lengthening (aka elongation), oftentimes working in concert with an antagonist muscle to control joint and limb segment motion (Table 10.1).

• In isometric contraction, muscle length remains constant during contraction.

• Some muscle activity can be concentric, in which the muscle shortens to move a joint through space.

  • Hip flexors advance the limb forward during swing phase, and the motion trajectory of the advancing limb is fine tuned by the decelerating action of the hip extensors during terminal swing and before IC.

  • The anterior tibialis has both eccentric (IC) and concentric (swing) muscle actions during normal gait. The posterior tibialis inverts the hindfoot and locks the transverse tarsal joints in the terminal stance to facilitate the heel rise and toe-off by the gastrocnemius muscles.

     

    Table 10.1

     

    Major Muscle Action and Function.

     

     

    Muscle Action Function
    Gluteus medius	Eccentric	Controls pelvic tilt (midstance)
    Gluteus maximus	Concentric	Powers hip extension
    Iliopsoas	Concentric	Powers hip flexion
    Hip adductors	Eccentric	Control lateral sway (late stance)
    Quadriceps	Eccentric	Stabilizes knee at initial contact and preswing
    Hamstrings	Eccentric	Control rate of knee extension at swing
    Tibialis anterior	Concentric	Dorsiflexes ankle at swing
    	Eccentric a	Slows plantar flexion rate during initial contact
    Gastrocnemius-soleus	Eccentric	Slows dorsiflexion rate (stance)

    a Predominant role.

     

    Pathologic Gait

• Factors that lead to abnormal gait include muscle weakness, neurologic conditions, pain, limb deformity, and joint disease (Table 10.2).

  • Muscle weakness or paralysis: decreases ability to control joint movement. Walking strategies develop on the basis of the specific muscle or muscle groups involved and the ability of the individual to execute adaptation—that is, effective substitutions replacing or compensating for deficient muscle action(s).

  • Neurologic conditions: may alter gait by producing muscle weakness, loss of balance, reduced coordination between agonist and antagonist muscle groups (i.e., spasticity), and joint contracture.

    • Hip scissoring is associated with overactive adductors, and knee flexion may be caused by hamstring spasticity or knee extensor weakness.

    • Equinus deformity of the foot and ankle may result in steppage gait (exaggerated knee flexion through swing, to effect clearance for the advancing limb) and hyperextension moment through the knee during stance phase.

  • Pain in a limb: creates an antalgic gait pattern in which the individual shortens stance phase to lessen the time the painful limb is loaded.

    The contralateral swing phase is more rapid.

     

    Table 10.2

     

     

     

     

     

     

     

    Gait Abnormalities.

     

     

    Phase of Gait	Abnormalities	Hip	Knee	Ankle/Foot	Alignm
    IC	Foot slap			Dorsiflexion weak
    IC–MS	Genu recurvatum		Quadriceps weakness or shortness or spasticity Hamstring weakness (compensated)	Achilles contracture Plantar flexor spasticity
    	Excessive foot supination			Forefoot valgus (compensated) Pes cavus	Short l
    	Excessive trunk extension	Hip extensor or flexor weakness Pain	Decreased range of movement
    	Excessive trunk flexion	Gluteus maximus weakness Flexion contracture	Quadriceps weakness
    IC– PSw	Excessive knee flexion (Crouch gait)	Flexion contracture	Hamstring contracture	Increased dorsiflexion Plantar flexor weakness	Long li
    	Excessive medial femur rotation		Medial hamstring tightness Opposite muscle weakness Anteverted femur shaft
    	Excessive lateral femur rotation		Lateral hamstrings tightness Opposite muscle weakness Retroverted femur shaft
    	Wide base of support	Abductor contracture	Genu valgus		Discrep Inst
    	Narrow base of support	Adductor contracture	Genu varum

    LR– PSw	Excessive trunk lateral flexion	Gluteus medius weakness (ipsilateral) Pain
    	Pelvic drop	Gluteus medius weakness (contralateral)
    	Waddling gait	Gluteus medius weakness (bilateral)
    Table C

     

    Phase of Gait	Abnormalities	Hip	Knee	Ankle/Foot	Alignm
    MS– PSw	Excessive foot pronation			Valgus deformity of forefoot (uncompensated) Varus deformity of forefoot and hindfoot (compensated) Pes planus Decreased dorsiflexion Tibialis posterior weakness	Fem i ( Tibi Lon
    	Bouncing			Achilles contracture Plantar flexor spasticity
    	Insufficient push-off			Achilles rupture Plantar flexor weakness Metatarsalgia Hallux rigidus
    	Inadequate hip extension	Flexor contracture Extensor weakness
    Swing	Steppage gait (footdrop)			Dorsiflexion weakness Plantar flexor spasticity Equines deformity
    	Circumduction	Abductor shortening or overuse	Stiffness		Long li

     

     

     

     

     

     

    Hip hiking

    Quadratus lumborum shortening

    Hamstring weakness Stiffness

    Long li

     

    ‌

    Adapted from Cuccurullo SJ, et al: Physical medicine and rehabilitation board review, ed 3, New York, 2015, Demos Medical.

     

  • Joint abnormalities: alter gait by changing the range of motion of the affected joint or producing pain.

    • A hip and knee with arthritis may have joint contractures and reduced range of motion.

    • An anterior cruciate–deficient knee has quadriceps-avoidance gait, which represents a decreased quadriceps moment during midstance. The patient compensates with forward flexion of the trunk, plantar flexion of the ankle, and sometimes use of the hand to hyperextend the knee.

  • Hemiplegia: characterized by prolongation of stance and double-limb support

    • Gait impairment may consist of excessive plantar flexion, weakness, and balance problems.

    • Associated problems are ankle equinus, limitation of knee flexion, and increased hip flexion.

  • Crutches and canes: devices that ameliorate instability and pain

    • Crutches increase stability by providing two additional load points.

    • A cane helps shift the center of gravity to the affected side when the cane is used in the opposite hand. This shift decreases the joint reaction of the lower limb and reduces the pain. (See Chapter 5, Adult Reconstruction.)

  • Arthritis: forces across knee may be four to seven times those of the body weight; 70% of load across knee occurs through medial compartment.

  • Water walking: significant decrease in joint moments and total joint contact forces due to buoyancy

    Section 2 Amputations Introduction

• All or part of a limb may be amputated to treat peripheral vascular disease, trauma, burn, tumor, infection, or a congenital anomaly.

• Should be considered a reconstructive procedure, often performed as an alternative to limb salvage

• An interdisciplinary team approach should be employed to help patient deal with psychologic implications and alteration of body self-image.

   

  Metabolic Cost of Amputee Gait

• Metabolic cost of walking is increased with proximal-level amputations and inversely proportional to length of residual limb and number of functional joints preserved.

• With a proximal amputation, patient has a decreased self-selected maximum walking speed.

• The higher the level of amputation (or the shorter the residual limb), the higher the metabolic demand; thus the transfemoral amputee with peripheral vascular disease may have an obligate doubling of energy expenditure while walking (Table 10.3). (Commonly tested exception to this rule: a Syme amputation is more energy efficient than the more distal midfoot [Chopart] amputation.)

• Of note is that the required increase in energy expenditure for ambulation in bilateral transtibial amputation (40%–50%) is less than that of unilateral transfemoral amputation (65%–75%).

   

  Load Transfer

• Soft tissue acts as an interface between the bone of the residual limb and the prosthetic socket.

   

  Table 10.3

   

  Energy Expenditure for Ambulation.

   

   

  Amputation Level	Energy Above Baseline Required (%)	Speed (m/min)	O2 Cost (mL/kg/m)
  Long transtibial	10	70	0.17
  Average transtibial	25	60	0.20
  Short transtibial	40	50	0.20
  Bilateral transtibial	41	50	0.20
  Transfemoral	65	40	0.28
  Wheelchair	0–8	70	0.16

  • The optimal soft tissue interface is composed of a well-attached mobile mass covering the bone end and full-thickness skin that tolerates the direct pressures within the prosthetic socket.

• Load transfer (i.e., weight bearing) occurs either directly or indirectly.

  • Direct load transfer (i.e., terminal weight bearing) occurs in knee (through-knee) or ankle disarticulation (Syme); intimacy of prosthetic socket fit is necessary only for suspension.

  • Indirect load transfer occurs in transosseous amputation through a long bone (i.e., transfemoral or transtibial). The end of the stump does not take all the weight, and the load is transferred indirectly by the total contact method. The process requires an intimate fit of the prosthetic socket.

     

    Amputation Wound Healing

• Healing of amputation wounds depends on several factors, including nutrition, adequate immune status, and vascular supply. Transcutaneous partial pressure of oxygen (TcPO 2) is the factor most predictive of successful wound healing.

  • Nutrition and immune status:

    • Patients with malnutrition or immune deficiency have a high rate of wound failure or infection. A serum albumin level of less than 3.5 g/dL indicates that a patient is malnourished. An absolute lymphocyte count of less than 1500 cells/mm3 is a sign of immune deficiency.

    • If possible, amputation surgery should be delayed in patients with stable gangrene until these values can be improved by nutritional support, usually in the form of oral hyperalimentation.

    • In severely affected patients, nasogastric or percutaneous gastric feeding tubes are sometimes essential.

    • When infection or severe ischemic pain necessitates urgent surgery, open amputation at the most distal viable level, followed by open-wound management, can be accomplished until wound healing can be optimized.

  • Vascular supply: oxygenated blood is a prerequisite for wound healing, and a hemoglobin concentration of more than 10 g/dL is necessary.

    Amputation wounds generally heal by collateral flow; thus, arteriography is rarely useful for predicting the success of wound healing.

    • Standard Doppler ultrasonography helps measure arterial pressure and has been used as the measure of vascular inflow to predict the success of wound healing in the ischemic limb.

      • An absolute Doppler pressure of 70 mm Hg was originally described as the minimum inflow pressure to support wound healing.

      • The ischemic index is the ratio of the Doppler pressure at the level being tested to the brachial systolic pressure. It is generally accepted that patients require an ischemic index of 0.5 or greater at the surgical level to support wound healing. The ischemic index at the ankle (i.e., the ankle-brachial index) is the most accepted method for assessing adequate inflow to the ischemic limb.

      • In the normal limb, the area under the Doppler waveform tracing is a measure of flow. In at least 15% of patients with diabetes and peripheral vascular disease, those values are falsely elevated and not predictive because of the incompressibility and loss of compliance of calcified peripheral arteries. The ischemic index for toe pressure is more accurate in such patients and, if greater than 0.45, is usually predictive of adequate blood flow.

    • TcPO 2 is the current gold standard for measurement of

      vascular inflow. It reflects the oxygen-delivering capacity of

      the vascular system to the level of contemplated surgery.

      • Values higher than 40 mm Hg (ideally 45 mm Hg) are correlated with acceptable rates of uneventful wound healing, without the false-positive values seen in noncompliant diseased peripheral vascular vessels.

      • Values higher than 30 mm Hg are also associated with healing.

      • Values lower than 20 mm Hg are predictive of poor healing potential.

         

        Pediatric Amputation

• Pediatric amputations are usually undertaken because of congenital limb deficiencies, trauma, or tumors.

• Congenital limb deficiencies are the result of failure of formation. The most common congenital limb deficiency is left transverse transradial deficiency.

• The International Society for Prosthetics and Orthotics (ISPO) classified limb deficiencies as either longitudinal (with some remaining distal portions) or transverse (without remaining distal portions). The Frantz classification describes limb deficiencies as terminal (complete loss of distal extremity) or intercalary (partial loss of intermediate parts with remaining proximal and distal parts).

• Amputation is rarely indicated in congenital upper limb deficiency; even rudimentary appendages can be functionally useful. In the lower limb, amputation of an unstable segment may allow direct load transfer and enhanced walking (e.g., Syme amputation for fibular hemimelia).

• In a growing child, disarticulations should be performed only when it is possible to maintain maximum residual limb length and prevent terminal bony overgrowth.

  • Such overgrowth usually occurs in the humerus, fibula, tibia, and femur, in that order; it is typical in diaphyseal amputations.

  • Numerous surgical procedures have been described to resolve this problem, but the best method is surgical revision of the residual limb with adequate resection of bone or autogenous osteochondral stump capping (Fig. 10.5).

     

    Amputation After Trauma

• The grading scales for evaluating mangled extremities are not absolute predictors but provide reasonable guidelines for determining whether salvage is appropriate. The extent of soft tissue injury has the greatest impact on the

decision-making process. Outcomes following amputation are improved with psychologic counseling and coping mechanisms.

 

 

 

FIG. 10.5 Diagram of the stump-capping procedure. The bone end has been split longitudinally.

Adapted from Bernd L et al: The autologous stump plasty: treatment for bony overgrowth in juvenile amputees, J Bone Joint Surg Br 73:203–206, 1991.

 

• Indications

   

  • The absolute indication for amputation after trauma is an ischemic limb with a vascular injury that cannot be repaired.

  • The guidelines for immediate or early amputation of mangled upper limbs differ from those for mangled lower limbs.

  • Early amputation in appropriate scenarios may prevent

    emotional, marital, financial, and addiction problems.

    • Most grade IIIB and IIIC tibia fractures occur in young men who are laborers and may be more likely to return to gainful employment after amputation and prosthetic fitting.

    • Sensation is not as crucial in the lower limb as in the upper limb, and current lower limb prostheses more closely approximate normal function.

    • Disadvantages of limb salvage

      • Severe open tibia fractures that are managed by limb salvage rather than amputation are often associated with high rates of mortality and morbidity as a result of infection, increased energy expenditure for ambulation, and decreased potential to return to work.

      • Limb salvage for Gustilo-Anderson grades IIIB and IIIC open fractures of the tibia and fibula generally has poor functional outcomes and multiple complications, and many surgical procedures may be needed.

      • The salvaged lower extremity with an insensate plantar weight-bearing surface (loss of posterior tibial nerve), with associated major functional muscle and bone loss, is unlikely to provide a durable limb for stable walking and is a potential source of early or late sepsis.

  • Contraindications

    • Upper limb

      • When a salvaged upper limb remains sensate and has prehensile function, it will often function better than an amputated limb with prosthetic replacement.

      • Maintaining as much length as possible is the key to subsequent prosthetic use.

 

Risk Factors

• Lower limb

  • Lack of plantar sensation is not an absolute indication to amputate, because it may result from neurapraxia, which has been shown to resolve over long-term follow-up.

  • In the absence of other major factors, amputation should not be performed.

• Cognitive deficits

  • Prosthetic device candidacy requires that patients have the ability to care for the limb residua and prostheses; they must be able to learn new tasks (relating to proper prosthesis use/maintenance, hygienic practices, troubleshooting dysfunctions and discomfort, and triaging changes to residuum appearance).

    • Patients with cognitive deficits may need to have other caretakers actively involved to ensure safe and meaningful prosthetic enablement.

• Diabetes

 

• A majority of patients who undergo amputation are diabetic with relative immunodeficiency.

• The most important risk factors in amputation in diabetic patients are the presence of peripheral neuropathy and development of deformity and infection.

  • Peripheral vascular disease

    • Most of the other patients who undergo amputation are malnourished patients with peripheral vascular disease of sufficient magnitude to necessitate amputation, and their coronary and cerebral arteries are diseased.

    • Appropriate consultation with physiatry, physical therapy, social work, and psychiatry departments is important to determine rehabilitation potential.

    • Medical consultation helps determine cardiopulmonary reserve. The vascular surgeon should determine whether vascular reconstruction is feasible or appropriate.

    • The biologic amputation level is the most distal functional amputation level with a high probability of supporting wound healing.

      • This level is characterized by the presence of adequate viable local tissue to construct a residual limb capable of supporting weight bearing, an adequate vascular inflow, and serum albumin level and a total lymphocyte count sufficient to aid surgical wound healing.

      • Selection of an appropriate amputation level is determined by combination of the biologic amputation level with the rehabilitation potential in order to choose the level that maximizes ultimate functional independence.

      • Morbidity and mortality rates have remained unchanged for several decades; 30% of patients with peripheral vascular disease die in the first 3 months after amputation, and nearly 50% die within the first year.

        Musculoskeletal Tumors

  • Goal of surgery: to remove the tumor with clear surgical margins

  • Amputation versus limb salvage

    • Advances in chemotherapy, radiotherapy, and allograft or prosthetic reconstruction have made limb salvage a viable option in extremity sarcomas.

    • If adequate margins can be achieved with limb salvage, the decision can then be based on expected functional outcome.

    • Limb salvage has superior cosmetic outcome but, in comparison to amputation, it has higher rates of postoperative complications, including infection, aseptic loosening, and graft or prosthetic failure.

    • The advantage of limb salvage over amputation—with regard to energy expenditure to ambulate, quality-of-life measures, and function with activities of daily living—is controversial in the literature.

    • Expected functional outcome should include the psychosocial and body image values associated with limb salvage.

      • These concerns should be balanced with improved task performance and lesser concern for late mechanical injury associated with amputation and fitting of prosthetic limbs.

         

        Technical Considerations

  • Skin flaps should be of full thickness, and dissection between tissue planes should be avoided. Wounds should not be sutured under tension.

  • Periosteal stripping should be sufficient to allow for bone transection; this principle minimizes regenerative bony overgrowth.

  • Two main approaches entail securing transected muscles either (1) directly to the distal end of a long transected bone at resting tension (myodesis) or (2) to antagonist muscles (myoplasty) across fascial layers. Myodesis may afford better control of a long residual transected bone, within a socket; however, it should be employed only in patients whose microcirculation is sufficient to sustain soft tissue viability at the anchoring points.

  • All transected nerves variably form neuromas. These need not become symptomatic or distressing to the patient if nerve ends come to lie deep in a soft tissue envelope, away from externally transmitted pressures (i.e., with residuum manipulation or during socket wear and use). Crushing of peripheral nerves may contribute to postoperative phantom or limb pain.

  • Surgical technique is related to development of heterotopic ossification in residual limbs.

  • Rigid (postoperative) dressings help reduce swelling, decrease pain, and protect the residuum from trauma.

    Complications

  • Phantom limb sensation—the feeling that all or part of the amputated limb is present—may include formication, numbness, tingling, heaviness, and nondistressing sensations of coolness or slight burning. It occurs intermittently in almost all adults who have undergone amputation and it usually decreases with time following appropriate desensitization and regular prosthesis use.

  • Pain

     

  • Edema

• Phantom pain is a distressingly painful sensation in the limb segment that has been removed. Success in symptom relief has been reported with consistent prosthesis use, physical therapy, compression, mirror therapy, and transcutaneous nerve stimulation.

• Common causes of neuropathic residual pain include neuroma, entrapment of nerve endings by scar tissue, and complex regional pain syndrome (CRPS) or causalgia. Amputation should not be performed for CRPS.

• Localized somatic pain can be mechanical, occurring from poor trimming of bone or suturing of soft tissues; similarly, bony overgrowth in children can cause residual limb pain.

• Other common sources of somatic pain are infection, inflammation, ischemia, heterotopic ossification (HO), and arthritis.

• Pain referred to the limb occurs in a high number of cases.

   

• Postoperative edema occurs after amputation. It may impede wound healing and place significant tension on the tissues.

• Rigid dressings and soft compression help reduce the edema.

• Swelling occurring after stump maturation is usually caused by poor socket fit, medical problems, or trauma.

• The ideal shape of upper limb and transtibial residua is cylindrical.

  Transfemoral residual limb is ideally conical.

• Lack of distal (total) contact in a socket, due to proximal constriction, can result in negative pressure, impaired venous and lymphatic outflow, chronic lymphedema, and formation of verrucous plaque hyperplasia, with risk of secondary ulceration and infection. Verrucous plaques do not require harsh chemical, biochemical, or mechanical débridement and are reversible when total contact with the socket is restored; they may also be treated by a total-contact cast, which is changed regularly to accommodate the reduced edema.

  • Joint contractures

    • These complications are usually noted as hip abduction and flexion contractures and knee flexion contractures, which can be produced at the time of surgery by anchoring of the respective muscles with the joints in a flexed position or, more importantly, postoperatively by

      improper positioning and resultant mechanical imbalance.

    • They can be avoided by correct positioning of the amputated limb. The transtibial amputee should have the knee fully extended (elevated leg rest on a wheelchair, avoidance of pillow under the knee, etc., should be considered). Similarly, the transfemoral amputee should avoid putting a pillow under the stump or between the legs; such a patient would benefit from a pillow applied laterally to control hip abduction and/or from a sandbag placed atop the residuum to keep a neutral position. Early education on contracture avoidance positioning and stretching exercises is important.

  • Skin problems

    • Common skin issues after amputation are wound failure to heal, skin irritation, allergic contact dermatitis, ulcers, bursa, inclusion cyst, verrucous hyperplasia, and calluses.

    • Wound failure to heal occurs most often in patients with diabetes and those with vascular disease. If the wound is not amenable to local care, wedge excision of soft tissue and bone, with closure and without tension, is the preferred treatment.

       

      Upper Limb Amputations (Fig. 10.6)

  • Hand amputation

    • Transphalangeal, transmetacarpal, or transcarpal

    • Thumb opposition is the most important component of hand function.

      • Thumb reconstruction procedures include phalangization (deepening the web space to provide more mobile digits) and pollicization (moving a finger with its nerve and vessels to the site of an amputated thumb).

         

         

        FIG. 10.6 Composite illustration of common amputation levels.

         

  • Wrist disarticulation

    • Advantages

      • Wrist disarticulation has two advantages over transradial amputation.

        • Preservation of full elbow motion and forearm rotation because of preservation of the distal radioulnar joint

        • Improved prosthetic suspension because of the flare of the distal radius

      • Effective function can be obtained at this level of amputation. Forearm rotation and strength are directly related to the length of the transradial (below-elbow) residual limb.

    • Disadvantages

      • Wrist disarticulation provides challenges to the prosthetist that may outweigh its benefits.

      • Cosmetic disadvantage

        • Prosthetic limb is longer than contralateral limb.

        • If myoelectric components are used, the motor and battery cannot be hidden within the prosthetic shank.

  • Transradial amputation or elbow disarticulation

    • Complete brachial plexus injury and a nonfunctioning hand and forearm may be best treated by a transradial amputation or elbow disarticulation, which can be fitted with a prosthesis.

    • The length of residual limb is a major determinant of the strength of elbow flexion, the preservation of forearm rotation, and the degree of elbow and humerus needed for suspension. The optimal length of the residual limb is at the junction of the middle and distal thirds of the forearm, where the soft tissue envelope can be repaired by myodesis and the components of a myoelectric prosthesis can be hidden within the prosthetic shank.

    • Because the patient can maintain prosthetic function at this level only by being able to open and close the terminal device, retention of the elbow joint is essential.

    • Krukenberg amputation converts the ulna and radius into digits to provide prehensile function.

    • The length and shape of elbow disarticulation provides better suspension and lever-arm capacity than transradial amputation. To enhance suspension and reduce the need for shoulder harnessing, a 45- to 60-degree distal humeral osteotomy is performed.

    • Elbow disarticulation is recommended for growing children to preserve the epiphyseal plate and avoid bony overgrowth.

    • Elbow disarticulation poses prosthetic fitting challenges that result in a limb that is bulkier and longer than the sound limb.

    • Gangrene of the upper limb, when it is not due to Raynaud or Buerger disease, represents end-stage disease, especially in diabetic patients. Such patients usually do not survive beyond 24 months.

      • Localized finger amputations in these patients are unlikely to heal. When surgery becomes necessary, amputation should be performed at the transradial level to achieve wound healing during the final months of the patient’s life.

         

        Lower Limb Amputations (see Fig. 10.6)

  • Toe and ray amputations

    • Patients with ischemia generally ambulate with a propulsive gait pattern, so they suffer little disability from toe amputation.

    • Patients with traumatic amputations lose some stability after toe amputation in the late-stance phase.

    • The great toe should be amputated distal to the insertion of the flexor hallucis brevis.

    • Isolated second-toe amputation should be performed just distal to the proximal phalanx metaphyseal flare, leaving the stump to act as a buttress and prevent late hallux valgus.

    • Patients who undergo single outer (first or fifth) ray resections function well in standard shoes.

    • Resection of more than one ray leaves the forefoot narrow, which is difficult to fit in shoes and often results in a late equinus deformity.

    • Central ray resections are complicated by prolonged wound healing and rarely achieve better results than midfoot amputation.

  • Transmetatarsal and Lisfranc tarsal-metatarsal amputations

    • There is little functional difference in outcome between these two procedures. The long plantar flap acts as a myocutaneous flap and is preferred to fish-mouth dorsal-plantar flaps.

    • Transmetatarsal amputation should be performed through the proximal metaphyses to prevent late plantar pressure ulcers under the residual bone ends.

    • Percutaneous Achilles tendon lengthening should be performed with transmetatarsal and Lisfranc amputations to prevent late development of equinus or equinovarus deformity.

    • Late varus deformity can be corrected with transfer of the tibialis anterior tendon to the neck of the talus.

      • The second tarsometarsal joint should be osteotomized to preserve midfoot stability.

      • The soft tissue at the fifth metatarsal base should be preserved because it represents the insertion site of the peroneus brevis and tertius muscles, which act as antagonists to the posterior tibial tendon.

        • Failure to preserve these tissues results in inversion during gait.

    • Some writers have reported reasonable functional outcomes with hindfoot amputation (i.e., Chopart or Boyd amputation), but most experts recommend avoiding amputation at these levels if possible in patients with diabetes or vascular disease.

    • Although children have been reported to function reasonably well with transmetatarsal amputation alone, adults retain an inadequate lever arm and are prone to experience fixed equinus deformity of the heel if Achilles tendon lengthening and tibialis anterior tendon transfer are

      not also performed.

  • Ankle disarticulation (Syme amputation)

    • Often performed for forefoot trauma, this amputation allows direct load transfer and possible short-distance ambulation without a prosthesis. It is rarely complicated by late residual limb ulcers or tissue breakdown.

    • It provides a stable gait pattern that rarely necessitates prosthetic gait training after surgery.

    • The outcome is more energy efficient than that of a midfoot amputation, despite the fact that it is a more proximal level (commonly tested exception to the rule of energy efficiency and amputations).

    • Surgery should be performed in one stage, even in ischemic limbs with insensate heel pads.

    • The posterior tibial artery must be patent to ensure healing.

    • The malleoli and metaphyseal flares should be removed from the tibia and fibula, but the remaining tibial articular surface should be retained to provide a resilient residual limb.

    • The heel pad should be secured to the tibia either anteriorly through drill holes or posteriorly by securing the Achilles tendon.

  • Transtibial (below-knee) amputation

    • A long posterior myocutaneous flap is the preferred method of creating a soft tissue envelope, especially in patients with vascular disease, inasmuch as the direction of blood flow is from posterior to anterior.

    • The optimum bone length is at least 12 cm below the knee joint or longer if adequate amounts of the gastrocnemius or soleus muscle can be used to construct a durable soft tissue envelope.

    • The posterior muscle should be secured to the beveled anterior tibia by myodesis.

    • Rigid dressings are preferred during the early postoperative period, and early prosthetic fitting may be started, 5–21 days after surgery, if the residual limb is capable of transferring load and if the patient has a satisfactory physical reserve.

  • Knee disarticulation (through-knee amputation)

    • The current technique involves the use of a long posterior flap, with the gastrocnemius muscle as end padding.

    • The alternative is to use sagittal skin flaps and cover the end of the femur with the gastrocnemius muscle to act as a soft tissue envelope end pad.

    • The Mazet technique involves partial removal of the femoral condyles, an effective myodesis for the adductors as well as anterior and posterior compartment muscles, and appropriation of a partial patella in the intercondylar groove. The resultant residuum shape does not

      pose a challenge to fit, because it lacks the distal bulkiness/flaring otherwise present due to retained femoral condyles.

       

       

       

      FIG. 10.7 (A) Diagram showing attachment of the adductor magnus to the lateral part of the femur. (B) Diagram depicting attachment of the quadriceps over the adductor magnus.

      From Gottschalk F: Transfemoral amputation. In Bowker J, Michael J, editors: Atlas of limb prosthetics, St. Louis, 1992, Mosby–Year Book, pp 479–486.

       

    • The patellar tendon is sutured to the cruciate ligaments in the notch, leaving the patella on the anterior femur.

      • This level is generally used in nonambulatory patients who can support wound healing at the transtibial or distal level.

      • Data from the Lower Extremity Assessment Project (LEAP) study have demonstrated that knee disarticulations result in the slowest walking speed and produce the least self-reported satisfaction.

    • Knee disarticulation is muscle balanced and provides an excellent weight-bearing platform for sitting and a lever arm for bed-to-chair transfer. When this type of amputation is performed in a potential walker, it provides a residual limb for direct bed-to-chair transfer (end bearing).

  • Transfemoral (above-knee) amputation

    • This form of amputation increases the energy cost for walking.

    • Patients with transfemoral amputations who have peripheral vascular disease are unlikely to become efficient walkers; thus salvaging the limb at the knee disarticulation (transtibial level) is crucial for maintaining functional walking independence.

    • With greater femoral length, the lever arm, suspension, and limb

      advancement are optimized. The optimum transfemoral bone length is 12 cm above the knee joint to accommodate the prosthetic knee.

    • Adductor myodesis is important for maintaining femoral adduction during the stance phase to allow optimal prosthetic function (Fig.

      10.7).

    • The major deforming force is toward abduction and flexion. Adductor myodesis at normal muscle tension eliminates the problem of adductor roll in the groin. Transecting the adductor magnus results in a loss of 70% of the adductor pull (Fig. 10.8).

    • Rigid dressings are difficult to apply and maintain at this level. Elastic compression dressings are used and may be suspended about the opposite iliac crest.

       

       

      FIG. 10.8 Diagram of moment arms of the three adductor muscles (R1, R2, and R3). Loss of the distal attachment of the adductor magnus (AM) will result in a loss of 70% of the adductor pull. AB, Adductor brevis; AL, adductor longus.‌

      From Gottschalk FA et al: Does socket configuration influence the position of the femur in above-knee amputation? J Prosthet Orthot 2:94–102, 1989.

       

  • Hip disarticulation

    • This procedure is infrequently performed, and of the patients who undergo this amputation, only a few make meaningful use of prostheses because of the high energy requirements of walking.

    • Patients who have suffered trauma or who have tumors occasionally use the prostheses for limited activity. These patients sit in their prostheses and must use the torso to achieve momentum for “throwing” the limb forward to advance it.

      Section 3 Prostheses Upper Limb

  • Upper limb biomechanics

    • The shoulder provides the center of the radius of the functional sphere of the upper limb, and the range of motion of the shoulder dictates the functional placement and reach for the entire upper limb. The elbow acts as the caliper to position the hand for performing its tasks.

    • In a typical arm, tasks performed with the use of multiple joint segments usually occur simultaneously, whereas upper limb prostheses perform these same tasks sequentially; thus salvage of the joint and residual limb length are directly correlated with functional outcome.

    • Motion at the retained joints is essential for maximizing function.

    • Residual limb length is important for suspending the prosthetic socket and providing the lever arm necessary to “drive” the prosthesis through space.

  • Benefit of limb salvage

    • Limb salvage is more important for the upper limb, where sensation is crucial for function.

  • Timing of prosthetic fitting

    • Prosthetic fitting should be undertaken reasonably soon after amputation.

    • Prosthesis fitting for congenital limb deficiency should follow attainment of normal developmental milestones. The first fitting for transradial deficiency occurs at the age of 6–7 months, when the child achieves sitting balance; however, slightly delayed progression is recommended for transhumeral deficiency.

  • Types of prostheses for different levels of amputation

    • Midlength transradial amputation

      • Myoelectric prostheses provide good cosmesis and are used for sedentary work. They can be used in any position, including overhead activity, and are the most successful for patients with midlength transradial amputations, for whom only the terminal devices need to be activated.

      • Body-powered prostheses are advantageous in providing sensory feedback and are used for heavy labor. The terminal devices are activated by shoulder flexion and abduction. For optimal mechanical efficiency of a figure-of-eight harness, the harness ring must be at the spinous process of C7 and slightly to the nonamputated side.

    • Elbow disarticulation and transhumeral (above-elbow) amputations

      • When the residual forearm is too short to function as an adequate lever arm for driving a prosthesis through space, supracondylar suspension (Munster socket) and step-up hinges can be used to augment function.

      • In elbow disarticulation and transhumeral (above-elbow) amputations, two control cables are needed to complete the process of prehension; thus these levels of amputation have significantly less efficient outcomes, and the prostheses are heavier than those for amputation at the transradial level.

        • One cable controls elbow flexion and terminal device by using shoulder flexion and abduction, whereas the other one locks and unlocks the elbow by using simultaneous shoulder depression, abduction, and extension.

      • The best function with the least weight at the lowest cost is provided by hybrid prosthetic systems, in which myoelectric, traditional body-powered, and body-driven switch components are combined; for example, a hybrid prosthesis consisting of a body-powered prosthetic elbow and an myoelectric terminal device.

    • Proximal transhumeral and shoulder disarticulation amputations

      • When the lever-arm capacity of the humerus is lost in proximal transhumeral (proximal to the deltoid insertion) or shoulder disarticulation amputations, limited function can be achieved with a manual universal shoulder joint positioned with the opposite hand and combined with lightweight hybrid prosthetic components.

         

        Lower Limb

  • Medicare functional classification level (MFCL) provides recommendations on prosthesis prescription (Table 10.4).

  • The designs commonly used are nonarticulated, articulated, energy-storing/dynamic-resposne, and microprocessor-controlled prosthetic feet.

    • Articulated foot

      • Single-axis foot

        • Based on an ankle hinge that provides dorsiflexion and plantar flexion

        • Disadvantages include poor durability and cosmesis.

      • Multiaxial foot

        • Based on mechanical joints and flexible keel that

          allow motion in all three planes

    • Nonarticulated foot

      • Solid-ankle, cushioned-heel (SACH) foot

        • This has been the standard for decades and was appropriate for general use in patients with low levels of activity.

        • It may lead to overload problems on the nonamputated foot but is still used for the patients with K1 functional level in many developing countries because of cost-effectiveness and

      • Solid-ankle, flexible endoskeletal (SAFE) foot

        • Allows some inversion and eversion through the flexible keel with greater accommodation to uneven surface

      • Dynamic-response/energy-storing foot

        • Selection of the correct dynamic prosthetic foot depends on patient’s height, weight, activity level, access for maintenance, cosmesis, and funding.

        • The dynamic-response foot prostheses, including the Seattle foot, Carbon Copy II/III, and Flex Foot, allow amputees to undertake most normal activities (Fig. 10.9).

        • Dynamic-response foot prostheses may be grouped into articulated and nonarticulated.

           

           

          FIG. 10.9 (A) Flex Foot with carbon-fiber leaf and posterior projection of the keel for heel strike. (B) Flex Foot with split-toe configuration and leaf spring design. Courtesy Flex Foot, Inc, Aliso Viejo, California.‌

           

           

          Table 10.4

           

          Medicare Functional Classification Levels.

           

           

          Functional Level	Definition	Mobility with Prosthesis	Cadence	Prosthesis Recommendati
          K0	This patient does not have the ability or potential to ambulate or transfer safely with or without assistance and a prosthesis does not enhance their quality of life	This patient does not have the ability or potential to ambulate or transfer safely with or without assistance and a prosthesis does not	NA	For cosmetic pu

          	or mobility.	enhance their quality of life or mobility.
          K1	This patient has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed cadence—a typical limited or unlimited household ambulator.	Household distance; level surfaces	Fixed	Feet: SACH, axis Knees: man locking, activated control
          K2	This patient has the ability or potential for ambulation with the ability to traverse low-level environmental barriers such as curbs, stairs, or uneven surfaces—a typical community ambulator.	Limited community distances; low-level barriers	Fixed	Feet: multia flexible k Knees: weig activated control
          K3	The patient has the ability or potential for ambulation with variable cadence—a typical community ambulator with the ability to traverse most environmental barriers—and	Unlimited community distances; most barriers	Variable	Feet: multia energy-s Knees: hydr pneuma micropr controlle

          	may have vocational, therapeutic, or exercise activity that demands prosthetic use beyond simple locomotion.
          K4	The patient has the ability or potential for prosthetic ambulation that exceeds basic ambulation skills, exhibiting high impact, stress, or energy levels —typical of the prosthetic demands of the child, active adult, or athlete.	Unlimited community distances; most barriers; high-impact and high-endurance activities	Variable	Same as K3. Additional a specific compon may incl

          • Feet: ener storing r blades, climbing adapters

          • Knees: sp specific vocation specific mechani

           

          • Articulated dynamic-response foot

            • Allows inversion/eversion and rotation of the foot and is useful for activities on uneven surfaces

            • May absorb loads and decrease shear forces to the residual limb

            • Most dynamic-response feet have a flexible keel and are the standard for general use (Fig. 10.10). The keel deforms under load, becoming a spring and allowing dorsiflexion, thereby

              decreasing load on the normal side and providing a springlike response for push-off.

            • Posterior projection of the keel provides a response at heel strike for smooth transition through the stance phase. A sagittal split allows for moderate inversion or eversion.

          • Nonarticulated dynamic-response foot

             

      • Microprocessor-controlled foot

• This prosthesis can have a short or long keel. Shortened keels are not as responsive and are indicated for the moderate-activity ambulator, whereas long keels are for very high-demand activities.

• Separate prosthetic feet for running and lower-demand activities may be indicated.

   

  • Prosthetic shanks

• Internal power generation produces ankle dorsiflexion and plantar flexion to facilitate ambulation uphill.

• These are heavy and require frequent charging as well as protection from wet environments.

  • Prosthetic shanks provide the structural link between or among prosthetic components.

  • Two varieties exist: endoskeletal, with a soft exterior and load-bearing tubing inside (the most common), and exoskeletal, with a hard load-bearing exterior shell.

  • Rotator units are sometimes added for patients involved in twisting activities (e.g., golf) or for sitting.

  • Prosthetic knees (Table 10.5)

    • Prosthetic knees provide controlled knee motion in the prosthesis.

    • These components are used in transfemoral amputation and knee disarticulation and are chosen on the basis of the patient’s needs.

    • Alignment stability (position of the prosthetic knee in relation to the patient’s line of weight bearing) is important in the design and fitting of prosthetic knees. Placing the knee center of rotation posterior to the line of GRF allows control in the stance phase but makes flexion difficult. Alternatively, with the knee center of rotation placed anterior to the line of GRF, flexion is made easier but at the expense of control. Only the polycentric knee component offers the possibility of both options by having a variable center of rotation.

    • Several types of prosthetic knees are available:

      • Polycentric (four-bar linkage) knee (Fig. 10.11B): has a moving instant center of rotation that provides for different stability characteristics during the gait cycle and may allow increased flexion for sitting. It is recommended for patients with transfemoral amputations, those with knee disarticulations, and those with bilateral amputations.

         

         

         

        FIG. 10.10 Ceterus prosthetic foot with leaf spring and shock absorber.

        Courtesy Ossur Americas, Aliso Viejo, California.

         

      • Stance-phase control (weight-activated [safety]) knee (see Fig. 10.11A): functions like a constant-friction knee during the swing phase but “freezes” by application of high-friction housing when weight is applied to the limb. Its use is reserved primarily for older patients, those with very proximal amputations, and those walking on uneven terrain.

      • Fluid-control (hydraulic and pneumatic) knee: allows adjustment of cadence response by changing resistance to knee flexion by means of a piston mechanism. The design prevents excessive flexion and is extended earlier in the gait cycle, allowing a more fluid gait. The knee is best used in active patients who prefer greater utility and variability at the expense of more weight.

      • Constant-friction knee: essentially a hinge designed to dampen knee swing by means of a screw or rubber pad that applies friction to the knee bolt. It is designed for general utility and may be used on uneven terrain. It is the most common knee prosthesis for children. Its major disadvantages are that it allows only single-speed walking and that it relies solely on alignment for stance-phase stability; therefore it is not recommended for older, weaker patients.

      • Variable-friction (cadence-control) knee: allows resistance to knee flexion to increase as the knee extends by employing a number of staggered friction pads. This knee allows walking at different speeds but is neither durable nor available in endoskeletal systems.

      • Manual locking knee: consists of a constant-friction knee hinge with a positive lock in extension that can be unlocked to allow functioning similar to that of a constant-friction knee. The knee is often left locked in extension for more stability. It has limited indications and is used primarily in weak, unstable patients, those just learning to use prostheses, and blind amputees.

      • Microprocessor (microprocessor-controlled) knee: A microprocessor adjusts the setting and behavior of a knee mechanism (which can be rheomagnetic, hydraulic, or pneumatic) based on real-time multisensor integration (e.g., pressure sensors and accelerometers) correlating to patient movement.

  • Suspension systems: Suspension is provided in modern lower extremity prostheses primarily through socket design and suspension liners and sleeves. Straps and belts are usually used for supplementation.

    • Sockets are prosthetic components designed to provide comfortable functional control and even pressure distribution on the amputated residuum. Sockets can be single-walled and rigid or double-walled and typically composed of a more flexible inner thermoplastic socket surrounded by a rigid outer shell. In general, suction is the primary suspension modality used, and it is effected through achieving total

      contact between socket and residuum. The suction socket provides an airtight seal by means of a pressure differential between socket and atmosphere. An elevated vacuum system can be used to draw additional air out of the socket, and its usage is facilitated by the interface liners. Total-contact support of the residual limb surface prevents edema formation. In total-contact support, different areas have different loads.

       

       

      Table 10.5

       

      Characteristics of Various Prosthetic Knees.

       

       

      Characteristics
      Prposthetic Action Advantages Disadvantages Type
      Constant- friction	Limits flexion	Durable, long resistance	Decreased stability
      Variable- friction	Varies with flexion	Variable cadence	Poor durability
      Stance-control	Friction brake	Stability during stance	Poor durability, difficult to use on stairs
      Polycentric	Instant center moves	Stable, increased flexion	Poor durability, heavy
      Manual locking	Must be unlocked for sitting	Maximum stability	Abnormal gait
      Fluid-control	Deceleration in swing	Variable cadence	Weight, cost
      Microprocessor	Computer-programmed real-time adjustment of the knee’s actuator	Variable cadence, stability during stance	Increased cost and maintenance, weight

       

       

      FIG. 10.11 (A) Stance-phase control unit for transfemoral prosthesis. (B) Modular endoskeletal four-bar knee with hydraulic swing-phase control unit. (C) Microprocessor knee unit.

      Courtesy Otto Bock Orthopaedic Industries, Minneapolis, Minnesota.

       

      • Transfemoral socket

        • Quadrilateral socket, in which the posterior brim provides a shelf for the ischial tuberosity, has been the classic suspension system. However, the design made it difficult to keep the femur in adduction.

        • Narrow mediolateral (ischial containment) transfemoral socket distributes the proximal and medial concentrations of forces more evenly and also enhances rotational control of the socket.

      • Transtibial socket

        • Weight bearing by the patellar ligament (or tendon) loads all areas of the residual limb that tolerate weight (i.e., patellar tendon, medial tibial flare, anterior compartment, gastrocnemius muscle, and fibular shaft). Weight-intolerant areas include the tibial crest and tubercle, distal fibula and fibular head, peroneal nerve, and

          hamstring tendons.

        • The patellar tendon–bearing supracondylar/suprapatellar socket has proximal extensions over the distal femoral condyles and patella.

        • Total-surface weight bearing is different from total-contact weight bearing. With total-surface weight bearing, pressure is distributed more equally across the entire surface of the transtibial residual limb, and the interface liner material in the socket is important.

          • Thermoplastic elastomer (TPE), silicone, and urethane are available materials for liner; also, some manufactures offer hybrid gels— combinations of TPE and silicone.

          • Each gel type has benefits and certain indications for clinical use based on the gel properties (durometer, compressive resistance, adherence, etc.); however, more research is needed to guide gel selection.

    • A supracondylar suspension system is recommended when the residual limb is less than 5 cm long. The socket is designed to increase the surface area for pressure distribution by raising the medial and lateral socket brim. A wedge may be used in the soft liner.

      • A supracondylar-suprapatellar suspension system encloses the patella in the socket and has a bar proximal to the patella. This design also provides mediolateral stability, and no additional cuffs or straps are required. Corset-type prostheses can lead to verrucous hyperplasia and thigh atrophy, but they reduce socket loads, control the direction of swing, and provide some additional weight support.

    • In prosthetic sleeves, friction and negative pressure are used for suspension. The sleeves fit snugly to the upper third of the tibial prosthesis and are made from neoprene, latex, silicone, or TPE.

      • Transtibial suspension

        • Gel liner suspension systems with a locking pin constitute the preferred method of suspension.

        • Liners are made from silicone, urethane, or TPE.

           

           

          FIG. 10.12 (A) Gel liner suspension with locking pin. (B) Transtibial prosthesis with liner locked in place.

           

        • The sleeve rolls onto the stump, and the locking pin is then locked into the socket (Fig. 10.12).

        • The liner provides suspension through suction and friction and acts as the socket interface.

        • Prosthetic socks worn over the liner accommodate volume fluctuation.

        • This suspension allows unrestricted knee flexion and minimal piston action.

      • Transfemoral suspension

        • Vacuum (suction) suspension is frequently used.

        • It relies on surface tension, negative pressure, and muscle contraction.

        • A one-way expulsion valve helps maintain negative pressure, and no belts or straps are required. Stable body weight is required for this intimate fit.

        • Roll-on silicone or TPE liners may be used with or without locking pins.

        • The Silesian belt and total-elastic suspension (TES) belt are commonly used auxiliary suspension. The TES belt is made of neoprene, fastens around the waist, and spreads over a larger surface area (Fig. 10.13).

  • Common prosthetic problems

    • Transtibial prostheses (Table 10.6)

      • Pistoning during the swing phase of gait is usually caused by an ineffective suspension system.

      • Pistoning in the stance phase results from a poor socket fit or volume changes in the stump (a change in thickness of the stump sock may be needed).

      • Alignment problems are common.

      • Factors leading to pressure-related pain or redness should be identified and corrected.

      • Other problems may be related to the foot: too soft a heel results in excessive knee extension, whereas too hard a heel causes knee flexion and lateral rotation of the toes.

         

         

        FIG. 10.13 Total-elastic suspension belt for suspending a transfemoral socket.

        Courtesy Syncor Manufacturers, Green Bay, Wisconsin.

         

    • Transfemoral prostheses (Table 10.7)

      • A long prosthesis (height) and weak hip abductors can lead to circumduction, vaulting, and lateral trunk bending.

      • Hip flexion contractures and insufficient anterior socket support can cause excessive lumbar lordosis (compensatory).

      • Inadequate prosthetic knee flexion can result in a terminal knee snap for some types of knees.

      • A medial whip (heel-in, heel-out) can be caused by a varus knee, external rotation of the knee axis, or uncontrolled rotation of the socket due to improper fitting or donning.

      • A lateral whip (heel-out, heel-in) is caused by the opposite problem: valgus knee, internal rotation at knee, or

        uncontrolled rotation of socket due to improper fitting or donning.‌

    • Stair climbing

      • In general, amputees ascend stairs by leading with the normal limb and descend by leading with the prosthetic limb (“up with the good, down with the bad”).

        Section 4 Orthoses Introduction

  • The primary function of an orthosis is control of the motion of certain body segments.

  • Orthoses are used to protect long bones or unstable joints, support flexible deformities, and occasionally substitute for a functional task. They may be static, static progressive, or dynamic.

  • With few exceptions, orthoses are not indicated for correction of fixed deformities or for spastic deformities that cannot be easily controlled manually.

  • Orthoses are named according to the joints they control, the function they provide, and the method used to obtain or maintain that control (e.g., a short-leg, below-knee brace is an ankle-foot orthosis [AFO]).

     

    Shoes

  • Specific shoes can be used by themselves or in conjunction with foot orthoses. The Blucher (open throat) and the Bal (closed throat) are the two types of shoes commonly worn. The Blucher type is better in terms of accommodating foot orthoses.

  • Extra-depth shoes with a high toe box designed to dissipate local pressures over bony prominences (such as claw deformities) and are recommended for diabetic patients.

  • The plantar surface of an insensate foot is protected by use of a pressure-dissipating material. A paralytic or flexible foot deformity can be controlled with more rigid orthoses.

  • SACH heels absorb the shock of initial loading and lessen the transmission of force to the midfoot as the foot passes through the stance phase.

  • A rocker sole can lessen the bending forces on an arthritic or stiff midfoot during midstance as the foot changes from accepting the weight-bearing load to pushing off. It is useful in treating metatarsalgia, hallux rigidus, and other forefoot problems. For the rocker sole to be effective, it must be rigid.

  • Medial heel out-flaring is used to treat severe flatfoot of most causes. A foot orthosis is also necessary.

     

    Foot Orthoses

  • Most foot orthoses are used to align and support the foot; prevent, correct, or accommodate foot deformities; and improve foot function.

  • Three main types of foot orthosis are used: rigid, semirigid, and soft.

    • Rigid foot orthoses limit joint motion and stabilize flexible deformities.

    • Semirigid orthoses aim to provide some support as well as absorb shock.

    • Soft orthoses have the best shock-absorbing ability and are used to accommodate fixed deformities of the feet, especially neuropathic, dysvascular, and ulcerative disorders.

       

      Ankle-Foot Orthoses

  • The most commonly prescribed lower limb orthosis (AFO) is used to control the ankle joint. It may be fabricated with metal bars attached to the shoe or with TPE. The orthosis may be rigid, preventing ankle motion, or it can allow free or spring-assisted motion in either plane.

  • After hindfoot fusions, the primary orthotic goals are absorption of GRF, protection of the fusion sites, and protection of the midfoot. In addition, AFOs are commonly prescribed for footdrop, plantar spasticity, and spinal cord injury.

  • The TPE foot section achieves mediolateral control of various degrees with different trimlines. Choice of full/anterior, intermediate, and posterior trimlines takes into consideration the intended function, level of control, as well as medical comorbidities, such as limb sensation and recurrent swelling.

  • When ankle motion is present, an articulating AFO permits motion through a mechanical ankle joint design.

  • Primary factors in selection of an orthotic joint include range of motion, durability, adjustability, and the biomechanical effect on the knee joint.

     

    Knee-Ankle-Foot Orthosis

  • The knee-ankle-foot orthosis (KAFO) extends from the upper thigh to the foot. It is generally used to control an unstable knee joint. It provides mediolateral stability with the prescribed amounts of flexion or extension control.

  • The stability of knee joints in KAFOs can be provided by various designs and use of knee locks of different types.

  • A subset of KAFOs are knee orthoses, which can be used to relieve pain of knee osteoarthritis, stabilize the patella or ACL deficient knee, or facilitate postoperative rehabilitation.

     

    Hip-Knee-Ankle-Foot Orthosis

  • The hip-knee-ankle-foot orthosis (HKAFO) provides hip and pelvic stability but is rarely used by paraplegic adults because of the cumbersome nature of the orthosis and the magnitude of effort in achieving minimal gains.

  • In experimental studies, it is being used in conjunction with implanted electrodes

and the computerized functional stimulation of paraplegic patients.

 

 

Table 10.6

 

 

 

Gait Abnormalities With Transtibial Prostheses.

 

 

Prosthetic Causes (Alignment Factors) Foot Ankle Gait Phase Abnormality Anterior Posterior Displacement Displacement Inset Outset Plantar to Socket to Socket flexion
Early stance	Knee excessive flexion (high pressure at anterior and distal tibia) at initial contact/loading response
	Knee excessive extension (or limited flexion) at initial contact/loading response
	Toe off floor after initial contact
Throughout stance	Knee extended too much (recurvatum)
	Knee flexed too much (instability)
	Knee valgus (pain/pressure on the distal medial and proximal lateral sides)

	Knee varus (pain/pressure on the distal lateral and proximal medial sides)
	High pressure against patella
	Prosthesis seemingly short (hip level)
	Pistoning
	Lateral bending (truncal lean)
	Broad-based gait
	Short step length
Late stance
	Early heel rise
	Late heel rise (“hill-climbing”)
	Drop-off on the sound side
Swing	Circumduction

	Vaulting of sound side
	Pistoning
Standing	Toe off
	Heel off

 

 

Table 10.7

 

Gait Abnormalities With Transfemoral Prostheses.

 

 

Prosthesis Factors Total Suspension Length			Socket Design	Socket Alignment	Knee
STANCE
Foot slap at initial contact
Foot rotation at initial contact		Loose		Flexion excessive
Instability of prosthetic knee during loading response				Flexion excessive	Displaced anteriorly Mechanical failure of knee unit
Drop-off at the end of stance				Socket too anterior in relation to foot

Lateral bending (truncal lean)	Short		Medial wall too high Lateral wall support insufficient	Abduction
Exaggerated lordosis			Anterior brim insufficient; higher posterior brim	Flexion insufficient	Displaced anteriorly
Abducted (wide-based) gait	Long		Medial wall too high Lateral wall support insufficient	Adduction built-in
Asymmetric step length				Flexion insufficient	Friction or flexion dampening insufficient Extension aid inadequate
Short stance duration					Friction or flexion dampening insufficient

 

Prosthesis Factors Total Suspension Length			Socket Design	Socket Alignment	Knee	Foot
SWING
Medio/lateral whip at the beginning of swing		Too tight		Socket rotated on limb due to	Rotation excessive (lateral whip:	Toe brea align poorl

				improper donning or fitting	internal rotation; medial whip: external rotation) Valgus (lateral whip) or varus (medial whip)
Rapid heel rise at the beginning of swing					Friction or flexion dampening insufficient Extension aid inadequate
Circumducted gait	Long	Inadequate			Friction or flexion dampening excessive Extension aid excessive Displaced posteriorly
Vaulting (on sound side)	Long	Inadequate			Flexion limited (lock, extension aid excessive)
Terminal swing impact					Friction or flexion dampening insufficient Extension aid excessive

 

• In children with upper-level lumbar myelomeningocele, the reciprocating gait orthoses are modified HKAFOs that can be used for therapeutic upright activities and simulated walking as a complement to wheelchair use.

   

  Elbow Orthosis

• Hinged-elbow orthoses provide minimum stability in the treatment of ligament instability.

• Dynamic spring-loaded orthoses have been successfully used in the treatment of flexion and extension contractures.

• An elbow strap is used to treat lateral epicondylitis. In addition, a long arm splint with the elbow flexed at 45 degrees can be tried to treat cubital tunnel syndrome.

   

  Wrist-Hand Orthosis

• The most common use of wrist and hand orthoses (WHOs) today is for postoperative care after injury or reconstructive surgery. These devices can be static, static-progressive, or dynamic.

• The opponens splint is successful in prepositioning the thumb but impairs tactile sensation.

• Wrist-driven hand orthoses are used in patients with lower cervical quadriplegia. The devices may be body powered by tenodesis action or motor driven. Weight and cumbersomeness are the major limiting factors.

   

  Fracture Braces

• Fracture bracing remains a valuable treatment option for isolated fractures of the tibia and fibula.

• Prefabricated fracture orthoses can be used in simple foot and ankle fractures, ankle sprains, and simple hand injuries.

   

  Pediatric Orthoses

• Many dynamic orthoses are used by children to control motion without total immobilization.

• The Pavlik harness has become the mainstay for early treatment of developmental dislocation of the hip.

• Several dynamic orthoses have been used for containment in Perthes disease.

   

  Spine Orthoses

• Cervical spine

  • Numerous orthoses are used to immobilize the cervical spine.

  • Effective immobilization options range from the various types of collars, to posted orthoses that gain purchase about the shoulders and under the chin, to the halo vest, which achieves the most stability by the nature of its fixation into the skull.

• Thoracolumbar spine‌

  • Orthoses used to mechanically stabilize the back, thus reducing back pain, rely on three-point pressure mechanism and increasing body cavity pressure.

  • Three-point orthoses achieve their control through the length of their lever arm and the subsequent limitation of motion.

    Section 5 Surgery for Stroke and Closed-Head Injury Introduction

• The orthopaedic surgeon can play a role in early management of adult-acquired spasticity secondary to stroke or closed-head brain injury when spasticity interferes with the rehabilitation program.

  • Nonsurgical treatment

    • When functional joint ranging is insufficient to control the deformity, intervention is often indicated.

    • Interventional modalities may include orthotic prescription, serial casting, and motor point nerve blocks with short-acting (bupivacaine HCl) or long-acting (phenol 6% in glycerol or botulinum toxin type A [Botox]) agents.

    • Splinting a joint (e.g., the ankle) in the neutral position is not sufficient to prevent development of a contracture (e.g., equinus contracture).

    • Local anesthetic injection to the posterior tibial nerve or sciatic nerve before casting relieves pain and allows for maximum correction of the deformity.

    • Open nerve blocks may be warranted to avoid injecting mixed nerves with large sensory contributions.

    • Pre-procedure botulinum toxin injection, nerve block, or dynamic EMG is also beneficial for surgery planning.

  • Prerequisites for surgical treatment

    • Surgical intervention in adult-acquired spasticity should be delayed until the patient achieves maximal spontaneous motor recovery (6 months for stroke and 12 to 18 months for traumatic brain injury).

    • When patients reach a plateau in functional progress or the deformity impedes further progress, intervention may be considered.

    • Invasive procedures in this population should be adjuncts, not alternatives, to a standard functional rehabilitation program. Realistic goal setting for surgical outcomes is important and should be discussed among patient, family, and healthcare providers.

    • When surgery is considered as a method of improving function, patients should be screened for cognitive deficits, motivation, and body image awareness.

      • Patients should not be confused and must have adequate short-term memory and the capacity for new learning.

 

Lower Limb

• In addition to specific cognitive strengths, motivation is necessary for patients to use functional gains and participate in their rehabilitation programs.

• Body image awareness is essential for surgical intervention to become meaningful and potentially beneficial. Patients who lack awareness of a limb or its position in space should undergo therapy directed toward ameliorating these deficits before undergoing surgical intervention.

   

  • Balance is the best predictor of a patient’s ability to ambulate after acquired brain injury. The mainstay of treatment for the dynamic ankle equinus component of this gait deviation is to achieve ankle stability in the neutral position during initial floor contact (i.e., initial contact and stance) as well as floor clearance during the swing phase.

  • An adjustable AFO with ankle dorsiflexion and a plantar-flexion stop at the neutral position are often used during the recovery period, followed by a rigid AFO once the patient has reached a plateau in recovery.

  • When the dynamic equinus overcomes the holding power of the orthosis and the patient is unable to keep the brace in place, motor-balancing surgery is indicated.

  • The equinus deformity is treated by percutaneous lengthening of the Achilles tendon. Tendon lengthening procedures are also frequently used for hamstrings, iliopsoas, and hip adductor.

  • The dynamic varus-producing force in adults is the result of out-of-phase tibialis anterior muscle activity during the stance phase. This dynamic varus deformity is corrected by either split or complete lateral transfer of the tibialis anterior muscle.

     

    Upper Limb

  • There is a paucity of literature dealing with acquired spasticity in the upper limb. Invasive intervention can be considered for nonfunctional and functional goals.

    • Nonfunctional goals: surgical release of static contracture; generally performed to complement nursing care or hygiene when the fixed contracture or spastic component results in skin maceration or breakdown.

    • Functional goals: one functional use of static contracture release is to improve upper extremity “tracking” (i.e., arm swing) during walking.

      Most upper extremity surgery performed in this patient population has the goal of increasing prehensile hand function. The goal may be simply to improve placement, enabling use of the hand as a “paperweight,” or to achieve improved fine motor control. In patients with prehensile potential, surgery may allow the “one-handed” patient to be “two-handed” by increasing involved hand function from no function to assistive or from assistive to independent.‌

      • Screening: When the goal of surgery is to improve function, patients must first be screened for cognitive capacity, motivation, and body image awareness.

        • Patients must have the cognitive skills and learning capability to participate in their therapy after surgery and to functionally make use of their newly acquired skills at completion of the rehabilitation program.

        • If they are not motivated, they will not participate in the prolonged effort necessary to achieve meaningful functional improvement.

        • Patients with poor stereognosis or neglect (i.e., poor body image awareness) find that the involved hand “drifts” in space and is not “available” for use if they have not been carefully trained in visual compensation techniques.

      • Grading: Once it has been determined that the patient has the potential to make functional upper extremity gains with surgery, he or she is graded on the basis of hand placement, proprioception and sensibility, and voluntary motor control. Dynamic EMG is used when delineation of phasic motor activity is essential.

      • Methods: By means of fractional musculotendinous or step-cut (Z-plasty) methods, muscle unit lengthening of the agonist-deforming muscle units is combined with motor-balancing tendon transfers of the antagonists to achieve muscle balance and improve prehensile hand function. Brachioradialis transfer can be performed to reconstruct lateral pinch function of the thumb.

        Section 6 Postpolio Syndrome Cause

  • Polio is a viral disease affecting the anterior horn cells of the spinal cord. Postpolio syndrome, manifested as a new wave of progressive weakness below the functional baseline, is not a reactivation of the poliovirus but rather a “burnout” of the motor unit of the alpha motor neuron that has expanded in size.

  • The syndrome occurs after middle age, usually 30 to 40 years following the original polio illness.

  • Symptoms include progressive muscle and joint weakness and pain, general fatigue and exhaustion with minimal activity, muscle atrophy, breathing or swallowing problems, sleep-related breathing disorders (e.g., obstructive sleep apnea), and decreased tolerance of cold temperatures.

  • In most patients the syndrome progresses slowly, with symptomatic periods followed by periods of stability.

  • Affected patients use a high proportion of their capacity for normal activities of daily living. With aging and the drop-off of muscle units, they no longer have the reserves to perform their daily activities.

  • Risk factors for development of postpolio syndrome include severity of the initial polio illness, initial diagnosis as an adolescent or adult, longer recovery from initial illness, and engaging in physical activity to the point of exhaustion or fatigue.

     

    Treatment

  • Treatment comprises prescribed limited exercise combined with periods of rest so that muscles are maintained but not overtaxed.

  • Standard polio surgical procedures, combining contracture release, arthrodesis, and tendon transfer, are indicated when the deformity overcomes functional capacity.

  • The use of lightweight orthoses is important in helping patients remain functionally independent.

 

Testable Concepts‌

• Gait cycle is divided into stance and swing phases with 20%–30% of the gait cycle spent in double-limb support. Energy expenditure of walking decreases as the vertical and horizontal displacement of the body’s center of gravity is minimized.

• Muscle action across the joints is associated with the relationship of the joints of interest with ground reaction force, the mean loading-bearing vector throughout the gait cycle.

• The soft tissue in the residual limb serves as the interface through which load transfer or weight bearing takes place. Transected muscles can be sutured to antagonist muscles (myoplasty) or anchored directly to the distal end of a bone (myodesis), the latter providing better residual limb control.

• Common complications of amputation include phantom limb sensation, pain (somatic and neuropathic), edema, joint contracture, and skin problems. The prosthetic systems for upper limb amputation can be myoelectric, traditional body-powered, or hybrid.

• Medicare functional classification level (MFCL) provides recommendations on prosthesis proscription for lower limb amputations.

• Orthoses are used to control the motion of certain body parts, which can be indicated for the protection of long bones and unstable joints, support of flexible deformities, or substitution for functional deficits.

• Orthopedic surgery can be considered for spasticity if maximal spontaneous motor recovery is achieved and the patient retains adequate cognitive capacity, motivation, and body image awareness.