DEFINITION

Tibiotalocalcaneal arthrodesis is the surgical procedure to simultaneously fuse the ankle and the subtalar joints.

In cases of posttraumatic, neuropathic, or avascular talar body bone loss, tibiocalcaneal arthrodesis may be indicated. The term pantalar arthrodesis refers to the surgical procedure to fuse all bones that articulate with the talus: the distal tibia, calcaneus, navicular, and cuboid. In essence, this is a combined ankle and triple arthrodesis.

In our opinion, the term medullary refers to the inner marrow cavity of a long bone and the word

intramedullary is a redundant, less useful term.

The goal of tibiotalocalcaneal arthrodesis is to create a painfree ankle and hindfoot that are biomechanically stable and fused in functional position.

In our hands, tibiotalocalcaneal arthrodesis is a salvage operation performed for severe ankle and hindfoot deformity, bone loss, and pain.

 

 

ANATOMY

 

Tibiotalocalcaneal arthrodesis aims to recreate physiologic ankle and hindfoot alignment with a plantigrade foot position (the foot is at a 90-degree angle to the long axis of the tibia) and about 5 to 7 degrees of hindfoot valgus.3,10

 

In general, rotation of the foot relative to the longitudinal axis of the tibia in the coronal plane is congruent with the anterior tibia—that is, the second ray of the foot is usually in line with the anteromedial crest of the tibia.

 

Hindfoot position influences forefoot position. With longstanding ankle and hindfoot deformity, forefoot pronation, supination, adduction, and abduction may be affected. Proper positioning of a tibiotalocalcaneal arthrodesis must take forefoot position into account. Ideally, in stance phase, the foot has near-equal pressure

distribution under the heel and first and fifth metatarsal heads.11

 

NATURAL HISTORY

 

Severe ankle and hindfoot deformities and pathologic processes result in disabling pathomechanics and, when left untreated, often confine patients to cumbersome brace use, limited ambulation with assistive devices, or a

wheelchair.7

 

Tibiotalocalcaneal arthrodesis is a major reconstructive process usually applied to otherwise disabling conditions.5,6

 

Gellman et al2 noted that the dorsiflexion and plantarflexion deficits after ankle fusion compared to the nonfused contralateral ankle were 51% and 70%, respectively. Surprisingly, for tibiotalocalcaneal arthrodesis, dorsiflexion and plantarflexion deficits were 53% and 71%, respectively.

 

This same study concluded, however, that inversion and eversion were 40% less after tibiotalocalcaneal fusion than after tibiotalar fusion alone.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

The patient being considered for tibiotalocalcaneal arthrodesis with a medullary nail presents with a myriad of orthopaedic pathology affecting gait, weight bearing, and ability to earn a living.

 

This patient may present with limited mobility, an equinus posture associated with genu recurvatum, and transverse plane deformity ranging from severe varus and instability of the hindfoot through profound valgus and ulceration over the medial structures (FIG 1).6,9

 

The neuromuscular or neuropathic patient may present with ulceration, intrinsic muscle loss, and multiple fractures in various stages of healing.6

 

 

 

FIG 1 • Weight-bearing clinical photograph (A) and weight-bearing AP radiograph (B) of a 53-year-old laborer with persistent ankle and hindfoot varus instability after prior attempt at calcaneal osteotomy and lateral ligament reconstruction.

 

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FIG 2 • A. Reportedly, the only pair of high-heeled, high-topped boots that this 42-year-old woman was comfortable wearing 2 years after sustaining bilateral talus fractures malunited in equinus. B. Clinical appearance of this woman's foot in maximal passive left ankle dorsiflexion. C. Weight-bearing lateral radiograph of same woman. Note plantarflexion talus fracture malunion and posttraumatic osteoarthritis after open reduction and internal fixation.

 

 

The posttraumatic patient often has a compromised soft tissue envelope, previously placed hardware, and

already medullary canal sclerosis that must be considered in preoperative planning (FIG 2).7 Evaluation must include gait and weight-bearing posture, assessment of the soft tissue envelope, and a thorough neuromuscular examination.

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

We routinely obtain three weight-bearing radiographs of the ankle and foot. As many of these patients have deformity, we often obtain additional long-cassette radiographs of the ankle or even mechanical axis views of the lower leg from the hip to the foot.

 

Posttraumatic and osteoarthritis

 

Radiographs may reveal joint space narrowing, osteophyte formation, and subchondral sclerosis and cysts, all characteristic of osteoarthritis. Posttraumatic deformity and retained hardware may be identified and must be considered in preoperative planning (FIG 3).7,8,9

 

 

 

FIG 3 • Preoperative weight-bearing clinical appearance (A), AP radiograph (B), and (continued)

 

 

Rheumatoid arthritis and other inflammatory arthritides

 

 

 

Radiographs typically identify periarticular erosions and osteopenia.4 Neuropathic arthrosis or Charcot neuroarthropathy

 

In our experience, this presentation is radiographically characterized by numerous fractures or microfractures in various stages of healing, hypertrophic new bone formation, and loss of normal weight-bearing architecture.

 

Bone resorption may be seen, along with vascular calcification and joint subluxation or dislocation.6,12

 

Plain tomography or computed tomography (CT) may further define deformity, arthritis, bone loss, and prior malunion or nonunion (FIG 4).

 

 

We have not found three-dimensional CT reconstructions helpful in the routine setting.

 

CT is also useful in assessing progression toward union following tibiotalocalcaneal arthrodesis.

 

Magnetic resonance imaging (MRI) may complement CT by evaluating for fluid in and around the joints, bone marrow

 

44

edema, talar vascularity, infection, and periarticular tendon and ligament pathology (FIG 5).

 

 

 

FIG 3 • (continued) lateral radiograph (C) of an obese 69-year-old man after valgus nonunion of attempted tibiotalar arthrodesis.

 

 

Technetium 99 bone scans may be useful in the evaluation of osteonecrosis after talus fracture, arthritic involvement of one or several joints, stress fracture, or neoplasm.

 

Indium-labeled white blood cell scans can be helpful in the diagnosis of osteomyelitis or septic arthritis.

DIFFERENTIAL DIAGNOSIS

Primary and secondary osteoarthrosis, including posttraumatic osteoarthritis

Rheumatoid arthritis and other inflammatory arthritides (gout, pseudogout, pigmented villonodular synovitis, septic arthritis, psoriatic arthritis, spondyloarthropathy, Reiter syndrome)

Neuropathic arthropathy (diabetes mellitus, spinal cord injury, hereditary sensory and motor neuropathy, syringomyelia, congenital indifference to pain, alcoholism, peripheral nerve disease, tabes dorsalis, and leprosy)

Infectious arthritis (sepsis, open trauma, or previous surgical procedure for fixation of fractures)

Arthritis and joint subluxation resulting from generalized ligamentous laxity, mixed connective disease, posterior tibial tendinopathy, spring ligament insufficiency

 

 

 

 

FIG 4 • Coronal (A) and lateral (B) CT images of a 48-year-old man with massive osteochondral talar insufficiency.

 

 

 

FIG 5 • MRI demonstrating extensive bone involvement of the talus.

NONOPERATIVE MANAGEMENT

 

Selective (diagnostic) injection of local anesthetic may help locate the exact anatomic source of the patient's pain. Tibiotalar arthritis may be associated with a stiff, painful subtalar joint that has a relatively normal radiographic appearance.

 

The injection of 5 to 10 mL of 1% lidocaine into the subtalar joint can clarify whether the pain may not be isolated to the ankle but in fact be generated in both the ankle and subtalar joints.

 

This has important implications when considering isolated tibiotalar versus tibiotalocalcaneal arthrodesis. We do not routinely incorporate the subtalar joint into the arthrodesis when performing an ankle arthrodesis. In select cases of endstage ankle arthritis associated with severe deformity and talar bone loss, we consider including an otherwise normal asymptomatic subtalar joint in the fusion mass achieved for tibiotalocalcaneal fusion.

Alternatively, an injection carefully placed in the peroneal tenosynovial sheath may prove that pain may be related to the tendons rather than the joint.

 

Although often challenging for the patient with deformity, we recommend bracing for the patient with prohibitive medical illness or a dysvascular extremity, particularly for

 

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the patient with a nonfixed, passively correctible deformity. A custom-molded polypropylene ankle-foot orthosis (AFO) or a supramalleolar AFO with Velcro closures may be considered as an alternative to tibiotalocalcaneal

arthrodesis in poor surgical candidates (FIG 6).6

 

 

 

FIG 6 • Molded AFO can provide stability and serve as an alternative to operative intervention.

 

 

For the neuropathic patient in whom bracing can achieve a relatively plantigrade posture for the hindfoot and ankle, we prescribe a double metal upright AFO attached to an Oxford shoe that includes Plastazote liners (total contact inserts).

 

 

In our experience, polypropylene in-shoe braces lead to ulceration in these patients with complex deformity. In severe deformity, a Charcot retention orthotic walker (CROW) may prove effective.

 

Although we favor tibiotalocalcaneal arthrodesis for patients with posttraumatic arthritis and deformity, we have had some success in relieving pain and improving function with a patellar tendon-bearing brace for poor surgical candidates.

 

SURGICAL MANAGEMENT

Indications and Contraindications

 

Indications for tibiotalocalcaneal arthrodesis

 

 

 

Sequelae of degenerative, posttraumatic, or inflammatory arthritis Avascular necrosis of the talus

 

 

Severe instability or paralytic ankle and hindfoot weakness Neuropathic arthropathy Failed ankle arthroplasty with subtalar intrusion

 

 

 

Failed ankle arthrodesis with insufficient talar body Severe deformity of talipes equinovarus Neuromuscular disease

 

 

Skeletal defects after tumor resection Pseudarthrosis

 

Flail ankle

 

Absolute contraindications for tibiotalocalcaneal arthrodesis with internal fixation

 

 

 

Dysvascular extremity Active infection

 

Relative contraindication to tibiotalocalcaneal arthrodesis with closed nailing techniques

 

 

Severe, fixed deformity that precludes a colinear reduction of the tibia, talus, and calcaneus for rod placement

 

Preoperative Planning

 

We glean essential information for preoperative planning from a thorough history and physical examination of the soft tissue envelope, vascular status, degree of deformity, and assessment of the entire limb and contralateral limb. We review all imaging studies, including long-standing radiographs of the lower extremity. Many of these patients have comorbidities, so we ensure that medical clearance is obtained. The availability of implant and instruments is ascertained and arrangements for perioperative care are confirmed.

 

Positioning

 

The patient with severe preoperative valgus deformity is positioned supine on a radiolucent operating table with a well-padded bump under the ipsilateral buttock to rotate the involved extremity internally (FIG 7A). Another pad can be placed under the heel to facilitate cross-table fluoroscopic imaging. Alternatively and preferably, the

patient with neutral to varus deformity is positioned in the lateral position with the affected extremity up (FIG 7B).1,6,7

 

We pad bony prominences and use an axillary roll in the recumbent axilla.

 

The patient is usually fastened to the table with a beanbag and chest brace devices, and pneumatic tourniquet control at the level of the thigh is used.

 

Parenteral, prophylactic antibiotics are administered before the tourniquet is inflated.

 

 

 

FIG 7 • A. Patient is positioned on a beanbag in a modified lateral position that allows access to the medial and lateral foot. Note stack of folded sheets under foot to be operated. B. Lateral position on blankets to level the leg with the pelvis; this position still allows for external hip rotation to see the medial ankle joint.

 

 

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TECHNIQUES

• Exposure

For the patient with severe preoperative valgus, we make a longitudinally oriented incision over the medial malleolus starting just at the supramalleolar level and carried 2 to 3 cm distal to the tip of the medial malleolus.

 

 

This allows a subperiosteal approach to the ankle and the removal of medially based closing wedge osteotomies of diseased tibiotalar bone and cartilage to correct the preoperative valgus deformity.

 

We identify and protect the medial neurovascular structures during this approach.

 

For all patients other than those who present with severe preoperative valgus, we routinely use a lateral transfibular approach through a longitudinal incision over the distal fibula carried onto the sinus tarsi, curving slightly anteriorly as one extends beyond the distal end of the fibula.

 

This approach affords wide access to both the ankle and subtalar joints and eliminates the possibility of the lateral malleolus rubbing in normal shoe wear postoperatively, and the fibula serves as a source of abundant cancellous and corticocancellous bone graft material during the case (TECH FIG 1).

 

Fibular osteotomy should be especially considered at the time of hindfoot fusion if there is significant varus deformity or loss of tibial length relative to the fibula. Resect the distal fibula in a beveled fashion with a microsagittal saw no more than 3 cm proximal to the level of the tibiotalar joint to preserve the distal tibiofibular syndesmosis and thereby minimize postoperative discomfort caused by distal tibiofibular movement and crepitus.

 

We would like to clarify that the transfibular approach with or without fibulectomy is reserved for patients with severe deformity who are not candidates, nor will ever be candidates, for future ankle fusion takedown and conversion to total ankle arthroplasty (TAA). For patients who may be considered for future TAA, every attempt should be made to preserve anatomy, especially the fibula—that is, the arthrodesis should be performed via an anterior or posterior approach.

 

 

 

TECH FIG 1 • Lateral approach to the tibiotalar and subtalar joint after distal fibulectomy.

• Ankle Arthrotomy

   

  We use a lateral ankle arthrotomy with the incision carried over the sinus tarsi and subtalar joint to correct

  any deformity that may be present across the tibiotalar and subtalar joints and to prepare the joint surfaces by removing what is left of the diseased articular cartilage (TECH FIG 2).

   

  Small wedges of bone may be removed to obtain the appropriate plantigrade postoperative posture for the foot and ankle.

   

  These arthrotomies also leave space for insertion of bone graft as needed.

   

  Often, combined medial and lateral arthrotomies are needed to achieve the appropriate plantigrade posture of the foot and to remove medial malleolar prominence.

   

  In the case of the ankle with preoperative valgus deformity, we use a medial approach to the tibiotalar joint in combination with a limited lateral exposure to decorticate and decancellate the subtalar joint via a separate lateral incision over the sinus tarsi.

   

   

   

  TECH FIG 2 • The lateral arthrotomy, with removal of fibula, allows easy access to the ankle joint as well as extending to the subtalar joint.

• Plantar Incision for Guidewire Insertion and Reaming

   

  As is true with all other medullary fixation procedures, the starting point for insertion of the guidewire and subsequent medullary rod is critical to the success of the case.

   

  The correct starting point is midway between the tips of the medial and lateral malleoli, anterior to the subcalcaneal heel pad, and about 2.5 cm posterior to the transverse tarsal joints, in line with the longitudinal axis of the tibia (TECH FIG 3A).

   

  Make a 2-cm, longitudinally oriented plantar incision just anterior to the weight-bearing subcalcaneal heel pad.

   

  47

   

   

   

  TECH FIG 3 • A. Desired starting point for the guide pin and medullary nail. With deformity, establishing this starting point's relationship to the talus and tibia may require some manipulation of the subtalar and ankle joints, but it is generally attainable. B. The guidewire should align with the tibial shaft.

   

   

  After the incision is carried through dermis sharply, blunt dissection only is taken down to the plantar fascia, which is split longitudinally.

   

  The intrinsic muscles can be swept aside and the neurovascular bundle protected and retracted with the intrinsic flexors.

   

  Place a smooth Steinmann pin or a guidewire, over which is passed a cannulated drill to provide access to the talus and tibial medullary canal after calcaneal corticotomy (TECH FIG 3B).

   

  Confirm optimal insertion of the cannulated drill, which passes sequentially through the inferior cortex of the calcaneus, the calcaneal body, the subtalar joint, the talar body, across the ankle, and finally into the distal tibial canal, using intraoperative fluoroscopic views in both the anteroposterior (AP) and lateral planes.

   

  After removing the cannulated drill, pass a bulb-tipped guidewire through the calcaneus and talus into the distal tibial medullary canal.

   

  Pass a series of progressively larger, flexible reamers over the guidewire and use them to enlarge the tibiotalocalcaneal canal.

   

  We recommend that the final reamer diameter is a full 0.5 to 1 mm larger than the anticipated implant's diameter.

   

  In our experience, overreaming avoids the risk of intraoperative and postoperative fracture at the proximal tip of the rod without compromising the construct's stability.

   

  Overzealous reaming in osteopenic bone may result in an intraoperative tibial fracture that then warrants using a longer medullary nail for spanning the fracture. When in doubt, check the reamer position with the fluoroscope.

   

  We are aware of several articles reporting fractures of the tibia at the proximal portion of the medullary nail when the nail is left at the relatively sclerotic distal tibial diametaphyseal isthmus.

   

  When closing the plantar wound, use simple interrupted or horizontal mattress sutures for a flat rather than inverted skin edge closure.

• Nail Selection

   

  In most cases, a nail length of 15 to 18 cm suffices for tibiotalocalcaneal arthrodesis with the proximal extent of the nail in metaphyseal bone, distal to the diametaphyseal isthmus, where the risk of tibia fracture is greatest.

   

  Nail diameter is dictated by the size of the native tibia.

   

  In most cases, a 10-mm diameter nail affords satisfactory stability to allow progression toward fusion.

   

  Although we acknowledge that an increase in nail diameter affords greater strength to the construct, we caution that aggressive overreaming of the cortex to place a larger diameter nail may compromise the cortex, leading to a stress fracture.

   

   

  In profoundly neuropathic patients, we have used a long tibiotalocalcaneal nail that bypasses the distal tibial isthmus by a length equal to at least three times the diameter of the tibial canal measured at the level of the isthmus. A longer nail generally reduces the possibility of a distal tibial stress fracture, albeit by requiring more reaming of the tibia.

   

• Nail Placement across the Arthrodesis Site

  48

   

  We find that locking the nail to its targeting arm, with each of two drill bits inserted through the drill guides and the two proximal most screw holes in the nail before the nail and its targeting arm are tightened, ensures optimal alignment before placement.

   

  The medullary nail is attached to its alignment and targeting guide. As it is inserted in retrograde fashion at plantar foot, it is slightly internally rotated so that when the locking screws are passed from lateral to medial, they will pass into the tibia without impingement on the distal fibula (TECH FIG 4A).

   

   

   

  TECH FIG 4 • A. In our experience, internally rotating the nail and the guide slightly, posterior to anterior screws placed through the guide and the nail, tend to align optimally with the calcaneus. B. Follow-up radiograph demonstrating that the nail is slightly countersunk to avoid being prominent on the plantar surface of the foot. A nail that is slightly proud rarely creates a problem because that portion of the calcaneus is not weight bearing; in fact, it may afford some further support with the end of the nail engaged in the calcaneal cortex.

   

   

  During insertion, the distal aspect of the nail should be countersunk at least 5 mm cephalad to the plantar surface of the os calcis or at least countersunk the same distance that the surgeon anticipates achieving axial compression across the ankle and subtalar fusion sites. Be sure not to leave the nail prominent on the plantar aspect of the foot (TECH FIG 4B).

• Screw Placement in the Intramedullary Nail

   

  When determining the final position for the nail, we simultaneously estimate the position of locking holes in the nail relative to the distal tibia, the talar body, and the calcaneal body.

   

  It is preferable but not necessary to fill all the locking holes.

   

  Nail failure is likely to occur in the heavyset or neuropathic patient if locking holes are left open at the level of either the ankle or subtalar fusion site. Early reports of nail failure at the subtalar joint often noted failure to fuse the subtalar joint.

   

  An advantage of modern nail design includes placement of locking screws at various angles to one another.

   

  The position of the nail for the proximal screws into the tibia will dictate the final rotation; thus, the guide for the posteroanterior screw may be applied and used to check (including fluoroscopy) the later position for the posteroanterior screw in the calcaneus as well as the talar screws (TECH FIG 5A).

   

  A posterior to anterior calcaneal locking screw increases the torsional rigidity of the nail construct by at least 40% and improves purchase of the calcaneal bone exponentially when compared to simply locking in one plane relative to the long axis of the nail (TECH FIG 5B).

   

  Further manual compression and impaction can be done across the arthrodesis sites before the proximal interlocking screws are inserted. Some nails use an extramedullary compression device, whereas others use compression of the heel against the tibial screws.

   

  Some medullary rods include an in-line compression device that can provide up to 15 mm of compression across the ankle and subtalar fusion sites (TECH FIG 5C).

   

  Some nails also provide for compression of the talar screw proximally toward the tibial screws, further compressing the ankle joint 7 mm (TECH FIG 5D).

   

  Do not remove this compression until the rod is locked both in the talus and the calcaneus so that the benefits of compression across both fusion sites (ankle and subtalar) can be achieved.

   

  49

   

   

   

  TECH FIG 5 • A. The alignment guide provides a quick check of overall positioning before drilling the proximal tibial screws. The surgeon should make sure the posteroanterior screw will be hitting the posterior calcaneus at an appropriate height. B. The posteroanterior screw is predrilled and measured via the C-arm to discern the length, usually just posterior to the calcaneal cuboid joint. C. A wrench is used to tighten the bolt compressing the heel plate toward the tibial screws; this intramedullary compression force is then held with distal screws through talus and calcaneus. D. Intraoperative view of gold screwdriver advancing the talar screw 7 mm proximally to augment ankle compression.

• End Cap Insertion

   

  Although some surgeons consider the end cap optional, we routinely secure it to the distal end of the nail after removal of the targeting arm. It restricts medullary bleeding, limits heterotopic calcification, and protects the threads of the nail should extraction be needed later.

   

  Permanent radiographs may be obtained in the operating room, both with AP and lateral projection, to

  ascertain appropriate alignment, position, and fixation.

• Bone Grafting

   

  Autogenous or allograft bone grafting is done to improve healing rates.

   

  Medullary reamings can be mixed with a fibular autograft and inserted at the tibiotalar and subtalar fusion sites even before placement of the nail.

   

  After insertion of the nail, place bone graft anterior, lateral, and posterior to the fusion sites.

   

  For large defects, such as removal of ankle prostheses, a femoral head allograft may be cut to fit the large defect, and then the nail can be placed directly through the allograft (TECH FIG 6A-D).

   

  Because of the bleeding, cancellous surfaces of bone achieved at surgery, and the large amounts of bone graft employed, closed suction drainage is recommended.

   

  Some surgeons and investigators advocate internal or external electrical bone stimulators for improving healing rates in neuropathic, multiply operated patients or smokers.

   

  We have also used bone stimulation for patients with preexisting avascular necrosis at the arthrodesis site.

   

   

  50

   

   

   

  TECH FIG 6 • A,B. Preoperative AP and lateral views of failing Agility total ankle prosthesis. C,D. Postoperative AP and lateral views after placement of femoral head allograft (soaked in concentrated bone marrow aspirate) demonstrate the excellent stability of an intramedullary device in a complicated revision situation.

• Wound Closure

   

  Take care to approximate the tissues in the ankle region. A layered closure is preferable.

   

  Apply a sterile, nonadherent dressing with adequate padding from the tips of the toes to just below the knee.

   

  This dressing includes a posterior plaster splint with the ankle and foot at neutral position and a gentle compressive wrap over padding.

• Case Example

   

  The patient was a 58-year-old man with posttraumatic talar avascular necrosis who failed brace wear.

   

  Preoperative radiographs are shown in TECH FIG 7A-C. The patient had pain from tibiotalar arthritis due to talar dome collapse. With increasing talar collapse, the foot gradually migrated anterior to the tibia, a biomechanically unfavorable position.

   

  Postoperative radiographs are shown in TECH FIG 7D,E. Tibiotalocalcaneal arthrodesis with a medullary nail was performed. The anatomic relationship of the foot to the tibia has been reestablished. The nail is not proud on the plantar foot. Despite the relatively large diameter of the nail, a supplemental cannulated screw can be placed adjacent to the nail from the calcaneus to the anterior tibia to provide further support to the construct. Also, a large buttress (much like the flying buttress on a French cathedral) was placed on the posterior tibia and dorsal calcaneus to increase the surface area for fusion.

   

  51

   

   

   

  TECH FIG 7 • A-C. Preoperative weight-bearing ankle radiographs with avascular necrosis of the talar dome and some degree of anterior translation of the talus relative to the tibial axis. A. AP view. B. Mortise view. C. Lateral view. D,E. Postoperative weightbearing ankle radiographs of the same patient after tibiotalocalcaneal arthrodesis. Fusion appears to have been successful based on the bridging trabeculation at the arthrodesis sites. In our experience, the increased surface area afforded by the bone graft to the prepared posterior tibia and dorsal calcaneus increases the chance of fusion. Note that the physiologic relationship of talus to tibial shaft axis has been reestablished. Despite the nail's relatively large diameter, a supplemental cannulated screw could be passed adjacent to the nail to provide greater stability to the construct. D. AP view. E. Lateral view.

   

   

  PEARLS AND PITFALLS

  • The most important goal of tibiotalocalcaneal arthrodesis with medullary nail fixation is achieving satisfactory pain-free union of the ankle and hindfoot with the foot in optimal plantigrade posture.

  • In our experience, radiographic and clinical assessment on the operating table before completion of the case is most important in achieving plantigrade posture.

  • Intraoperative pearls include the need for appropriate positioning so that full access to the entire

   

  lower extremity is obtained.

   

  • We recommend that the patient with limited internal and external hip rotation should be positioned in slightly less than extreme lateral position to facilitate access to the medial malleolar side of the ankle and optimize AP imaging with a C-arm fluoroscope.

     

  • The optimal insertion point for the nail is immediately lateral to the plantar calcaneus' midpoint and in line with the longitudinal tibial axis.

     

  • Nail and targeting arm

     

    • Be sure that the targeting arm is rigidly coupled to the nail. Rigid coupling of the nail to its targeting arm in the appropriate position and alignment will save the surgeon a lot of effort and frustration in locking the nail proximally.

       

  • Medullary nailing for tibiotalocalcaneal arthrodesis in the face of open ulcers or wounds is not absolutely contraindicated, but ulcers or wounds should be clean, noncellulitic, and granulating before medullary nail fixation is considered.

     

  • Rotational alignment of the tibiotalocalcaneal arthrodesis: Satisfactory rotational alignment is most readily achieved by comparison to the contralateral uninvolved limb and by preserving the natural concave-convex relationship of the tibiotalar and subtalar fusion sites at the time of removal of diseased cartilage and subchondral bone.

     

  • Performing tibiotalocalcaneal arthrodesis with limited assistance: A holding pin from the calcaneus to the posterior tibia can help hold alignment during the reaming process (FIG 8).

 

 

52

 

FIG 8 • A holding pin from the calcaneus to the posterior tibia can help hold position when reaming and placing the nail as long as the pin remains out of the reamer's path.

 

 

 

POSTOPERATIVE CARE

 

Most patients undergoing tibiotalocalcaneal arthrodesis with medullary nail fixation can be discharged the day after surgery with oral analgesics and after having received 24 hours of parenteral antibiotics.

 

The typical case will require non-weight-bearing protection in a short-leg splint or cast for 6 weeks, followed by 4 to 6 weeks of weight bearing to tolerance in a short-leg walking cast.

 

At 10 to 12 weeks postoperatively, the patient is fitted with a removable fracture orthosis equipped with a rocker sole to ease the transition to weight bearing in more normal shoe wear by 12 to 16 weeks postoperatively.

 

Less than half of the patients fused in the appropriate plantigrade posture with otherwise normal neuromuscular function will have a noticeable limp by 6 to 12 months postoperatively.

 

Those requiring shoe wear modification are often best treated with a rocker bottom sole or a cushioned heel to make up for the rigidity of the fused joints.

 

Heel lifts can be employed to equalize limb lengths to within 10 to 15 mm; the side undergoing tibiotalocalcaneal fusion desirably being the short one to allow for toe clearance during the swing phase of gait.

 

The vast majority of our patients are ambulatory postoperatively in a noncustom, off-the-shelf shoe.

 

Rod removal has been required in less than 1% of Dr. Quill's operative series.

OUTCOMES

Medullary nail advantages over traditional fixation for arthrodesis of the ankle and hindfoot include the fact that a medullary nail is a load-sharing device that is especially indicated for the osteopenic or

 

 

neuroarthropathic patient. Dr. Quill's personal clinical series includes a 93% union rate in an average of

12.2 weeks postoperatively (range 10 to 20 weeks).10

Delayed nonunions have occurred in neuropathic patients, but most are asymptomatic.

Mean improvement in the American Orthopaedic Foot and Ankle Society (AOFAS) clinical scores for this series of patients has been 52 points.

Nail-related problems include the removal of 17 of 932 locking screws removed for fracture or local irritation. There have been two fractured nails, both of which were in the face of severe persistent valgus and subtalar nonunion in neuropathic, obese patients.

One tibial fracture was sustained intraoperatively in an osteopenic rheumatoid patient. It was incomplete and healed during routine casting.

Excellent early stability and rigid early fixation are achieved and maintained, providing for less perioperative morbidity and discomfort and shorter casting.

The medullary nail ensures position and alignment from the immediate postoperative time frame, and the patients often require less activity restriction postoperatively.

Medullary nail fixation for tibiotalocalcaneal arthrodesis has filled a particular niche in treating patients with severe deformities, disabilities, and bone loss who otherwise would have been severely disabled or would have needed to undergo limb amputation.

 

 

COMPLICATIONS

We have not encountered plantar wound healing problems in any patient when the procedure is done as described earlier.

Damage to the medial and lateral plantar nerves can be avoided by following the technique mentioned earlier and by dissecting with nothing sharper than a large key elevator deep to the dermis on the plantar aspect of the foot.

A three quarter-inch key elevator can be used to bluntly spread the fibers of the plantar fascia and the intrinsic flexor muscles in line with the incision and to sweep soft tissues medially and laterally before inserting the guidewire through the sole of the foot.

Complications of medullary nail fixation for ankle and hindfoot fusion include those germane to any orthopaedic procedure, such as infection, medical illness, and anesthetic perioperative complication as well as hardware prominence.

The complications unique to medullary nail fixation for tibiotalocalcaneal arthrodesis include delayed union, nonunion, and malunion and can be minimized by adhering to the technique described.

53

The proximal dissection for screw fixation may encounter the superficial peroneal nerve and the distal dissection may expose the sural nerve; care must be taken to avoid damage. In cases in which the medial malleolus is removed, the tibial nerve can be exposed to injury very easily.

 

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