DEFINITION

The HINTEGRA Total Ankle Prosthesis (Integra LifeSciences Corp., Plainsboro, NJ) is an unconstrained, three-component system that provides inversion-eversion stability (FIG 1). Axial rotation and normal flexion-extension mobility are provided by a mobile-bearing element.4,8,9,10

The HINTEGRA ankle includes a metal tibial component, an ultra-high-density polyethylene mobile bearing, and a metal talar component, all of which are available in six sizes. The metal components are made up of a cobalt-chromium alloy and coated with a 200-μm porous titanium and hydroxyapatite coating where osteointegration is necessary. The remaining metallic surfaces are highly polished.

The tibial component consists of a flat, 4-mm thick loading plate with six pyramidal peaks facing the tibia and an anterior shield that allows the fixation of the tibial component by two screws through two oval holes. The anatomically shaped flat surface ensures optimal contact with the subchondral bone, as well as optimal support of the cortical bone ring, providing a maximal load-transfer area. It further allows minimal resection (2 to 3 mm) of the subcortical bone to insert the implant. This fixation concept prevents stress shielding from occurring.

The talar component is conically shaped, with a smaller radius on the medial side. The articular surface is highly polished and has a 2.5-mm high rim on the medial and lateral side which ensures a stable position and guided rotation of the polyethylene bearing (flexion-extension). The medial and lateral talar surfaces are covered by two wings which through their anatomic shape cover the original cartilage-covered surface and allow press-fit of the component to the bone. Furthermore, the anterior shield increases the bone support on the weaker bone at the talar neck to increase stability in the sagittal plane and to prevent the adherence of scar tissue that might restrict motion. The current design, introduced in 2004, includes two pegs which facilitate the insertion of the talar component and provide additional stability.

 

 

 

FIG 1 • The HINTEGRA ankle consists of three components.

 

 

The high-density polyethylene mobile bearing (ultra-highmolecular-weight polyethylene) consists of a flat surface on the tibial side and a concave surface that perfectly matches the talar surface. It has a minimum thickness of 5 mm but is also available in thicker sizes (6, 7, and 9 mm). The size of the polyethylene bearing corresponds to the talar size. It fully covers the talar component, therefore ensures optimal stability against valgus-varus forces and minimal contact stress on both the primary and secondary articulating surfaces. The bearing is restrained by the compressive action of the collateral ligaments and adjacent tissues. Furthermore, compressive muscle forces and gravitational loads across the joint hold the bearing against the metallic articulating surfaces. Thus, when properly positioned, dislocation of the bearing is unlikely.

 

The HINTEGRA ankle provides 50 degrees of congruent contact flexion-extension and 50 degrees of congruent contact axial rotation. This provides congruent contact surfaces for normal load-bearing activities, even in the case of a distinct implantation error or preexisting deformity. Limits of motion depend on natural soft tissue constraints: With the HINTEGRA ankle, no mechanical prosthetic motion constraints are imposed for any natural ankle movement.

 

The HINTEGRA ankle uses all available bone surfaces for support. The anatomically shaped, flat tibial and talar components essentially resurface the tibia and the talar dome, respectively, and the wings hemiprosthetically replace degenerate medial and lateral facets (a potential source of pain and impingement).

 

ANATOMY

 

The superior extensor retinaculum is a thickening of the deep fascia above the ankle, running from tibia to fibula.

 

It includes, when looking from medial to lateral, the tendons of the tibialis anterior, the extensor hallucis longus, and the extensor digitorum longus.

 

The anterior neurovascular bundle lies roughly halfway between the malleoli; it can be found consistently between the extensor hallucis longus and the extensor digitorum longus tendons.

 

The neurovascular bundle contains the anterior tibial artery and the deep peroneal nerve. The nerve innervates the extensor digitorum brevis, the extensor hallucis brevis, and the sensory space interdigital I-II.

 

On the height of the talonavicular joint, the medial branches of the superficial peroneal nerve cross from lateral to medial. It supplies the skin of the dorsum of the foot.

 

 

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On the posterior aspect of the ankle, the medial neurovascular bundle is located behind its posteromedial corner and the flexor hallucis longus tendon on its posterior aspect. The deltoid ligament is a multibanded complex with superficial and deep components.

 

PATHOGENESIS

 

Primary osteoarthritis of the ankle joint is rare; degenerative disease of the ankle is more often seen after trauma and systemic diseases (eg, rheumatoid arthritis).1

 

Osteoarthritis of the ankle joint is often associated with malalignment, deformities, and instabilities of the foot, particularly in posttraumatic ankles.7

NATURAL HISTORY

 

Development of osteoarthritis of the ankle joint can take years, particularly in posttraumatic ankles (eg, after fractures and sprains).

 

Once symptomatic, osteoarthritic changes usually progress, resulting in pain under loading conditions and finally at rest as well.

 

If associated with instability or muscular dysfunction, misalignment and deformity may occur.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

A careful history is taken to assess the following:

 

 

 

 

 

Previous trauma Previous infections Underlying diseases Actual pain

 

Limitations in daily and sports activities

 

While the patient is standing, a thorough clinical investigation of both lower extremities is done to assess the following:

 

 

 

 

Alignment Deformities Foot position

 

Muscular atrophy

 

 

 

FIG 2 • Preoperative assessment includes weight-bearing standard radiographs as follows: (A) AP view of the ankle, (B) lateral view of the foot, (C) Saltzman alignment view, and (D) AP view of the foot.

 

 

While the patient is sitting with free-hanging feet, the examiner assesses the following:

 

 

 

The extent to which a deformity is correctable Preserved joint motion at the ankle and subtalar joints

 

 

Ligament stability of the ankle and subtalar joints with anterior drawer and tilt tests Supination and eversion power (eg, function of posterior tibial and peroneus brevis muscles)

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Plain weight-bearing radiographs, including anteroposterior (AP) views of the foot and ankle, a lateral view of the foot, and an alignment view of the hindfoot6 (FIG 2), are obtained to assess the following:

 

 

Extent of destruction of the tibiotalar joint (eg, tibia, talus, and fibula) Status of neighboring joints (eg, associated degenerative disease)

 

 

Deformities of the foot and ankle complex (eg, heel alignment, foot arch, talonavicular alignment) Tibiotalar malalignment (eg, varus, valgus, recurvatum, and antecurvatum)

 

Bony condition (eg, avascular necrosis, bony defects)

 

A computed tomography (CT) scan (FIG 3) may be ordered for assessment of the following:

 

 

 

Destruction of joint surfaces and incongruency Bony defects

 

Avascular necrosis

 

Single-photon emission computed tomography combined with computed tomography (SPECT-CT) with a superimposed bone scan (FIG 4) may be used to visualize the following:

 

 

 

Morphologic pathologies and associated activity process Biologic bone pathologies and associated activity process

 

Magnetic resonance (MR) imaging may be used to show the following:

 

 

Injuries to ligament structures

 

Morphologic changes of tendons

 

 

 

Avascular necrosis of bones (eg, talar body and tibial plafond) Gait analysis11

71

 

 

 

FIG 3 • Weight-bearing CT in a patient with varus deformity showing the wear process in the medial tibiotalar joint, the varus tilt of talus, and the valgus tilt of calcaneus subsequently to the peritalar instability: (A) AP coronal plane,

(B) sagittal plane, and (C) AP horizontal plane.

 

NONOPERATIVE MANAGEMENT

 

Although nonoperative management is controversial, patients with less debilitating pain and dysfunction may be treated nonoperatively.

 

Nonoperative treatment may consist of the following:

 

 

Shoe modifications to facilitate gait

 

 

Physiotherapy to decrease inflammatory response Anti-inflammatory medicine for acute pain

SURGICAL MANAGEMENT

 

Successful total ankle arthroplasty with an unconstrained three-component prosthesis demands thorough preoperative planning to address all associated pathologies.

 

During surgery, the surgeon must continuously check whether these associated pathologies are sufficiently addressed. For instance:

 

 

 

Whether preexisting deformities are sufficiently corrected Whether the foot is properly aligned

 

Whether soft tissues are sufficiently balanced

 

 

 

FIG 4 • SPECT-CT in a patient with valgus deformity showing the pathologic process in the lateral tibiotalar and fibulotalar joints. A. AP view. B. Lateral view.

 

 

Indications

 

 

 

Primary osteoarthritis (eg, degenerative disease) Systemic arthritis (eg, rheumatoid arthritis)

 

Posttraumatic osteoarthritis (if instability and malalignment are manageable)

 

Secondary osteoarthritis (eg, infection, avascular necrosis) (if at least two-thirds of the talar surface is preserved)

 

Salvage for failed total ankle replacement (if bone stock is sufficient)

 

 

Salvage for nonunion and malunion of ankle fusion (if bone stock is sufficient) Low demands for physical activities (hiking, swimming, biking, golfing)

 

Relative indications

 

 

 

Severe osteoporosis Immunosuppressive therapy

 

Increased demands for physical activities (eg, jogging, tennis, downhill skiing)

 

Bony avulsion fracture of medial malleolus (with or with-out fracture of the fibula-syndesmotic disruption)

 

 

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Contraindications

 

 

Infection

 

 

Avascular necrosis of more than one-third of the talus Unmanageable instability

 

 

 

 

Unmanageable malalignment Neuromuscular disorder Neuroarthropathy (Charcot) Diabetic syndrome

 

Suspected or documented metal allergy or intolerance

 

 

Highest demands for physical activities (eg, contact sports, jumping) Controversial indications

 

 

Diabetic syndrome without polyneuropathy Avascular necrosis of talus

Preoperative Planning

 

All imaging studies are reviewed.

 

Plain films should be reviewed to identify possible coexisting arthritis of adjacent joints as well as varus and valgus of the hindfoot and the longitudinal arch.

 

 

Associated foot deformity, malalignment, and instability should be addressed concurrently. Examination under anesthesia should be accomplished to compare with the contralateral ankle.

Positioning

 

The patient is positioned with the feet on the edge of the table.

 

 

The ipsilateral back is lifted until a strictly upward position of the foot is obtained. A block is placed under the affected foot to facilitate fluoroscopy during surgery.

 

 

The contralateral (nonaffected) leg is also draped if significant deformity is to be corrected. A tourniquet is applied on the ipsilateral thigh.

Approach

 

An anterior longitudinal incision 10 to 12 cm long is made to expose the retinaculum.

 

The retinaculum is dissected along the lateral border of the anterior tibial tendon, and the anterior aspect of the distal tibia is exposed.

 

While the soft tissue mantle is dissected with the periosteum from the bone, attention is paid to the neurovascular bundle that lies behind the long extensor hallucis tendon.

 

Capsulotomy and capsulectomy are done, and a self-retaining retractor is inserted to carefully keep the soft tissue mantle away (FIG 5).

 

Osteophytes on the tibia are removed, particularly on the anterolateral aspect.

 

 

Osteophytes on the talar neck and the anterior aspect of medial malleolus are also removed. The fibula usually cannot be fully visualized at this stage.

 

 

 

FIG 5 • The ankle joint is exposed through an anterior approach.

 

 

TECHNIQUES

• Tibial Resection

Position the tibial cutting block with its alignment rod using the tibial tuberosity (eg, the anterior cresta iliaca of pelvis in the case of leg deformity) (TECH FIG 1A) as the proximal reference and the anterior border of the ankle (eg, the center of the resection block is supposed to be at intermediate line of the tibiotalar joint) as the distal reference.

Make the final adjustment as follows:

Sagittal plane: Move the rod until a parallel position to the anterior border of the tibia has been achieved (TECH FIG 1B).

Frontal (coronal) plane: Frontal plane position is given by the position of the rod (eg, there is a fixed 90-degree angle between the resection surface and the rod). Once the rod is proximally centered to tibial tuberosity (TECH FIG 1C), two pins are used for fixation.

Vertical adjustment: Move the tibial resection block proximally until the desired resection height is achieved. Usually, resection of about 2 to 3 mm on the apex of the tibial plafond is desired. In varus ankles, more tibial resection is usually needed, whereas in valgus ankles or in presence of high joint

laxity, less bone resection is advised.

 

Rotational adjustment: Rotate the tibial resection block to get a parallel position of its medial surface to the medial surface of the talus (eg, to avoid damaging the malleoli with the saw blade during resection).

 

Slide the tibial cutting guide into the cutting block, creating a slot in which the saw blade will be guided. The width of the slot limits the excursion of the saw blade, thereby protecting the malleoli from being hit and fractured.

 

Once the tibial cut is made, a reciprocating saw might be used to finalize the cuts, particularly for the vertical cut on the medial side (TECH FIG 1D).

 

Remove the remaining bone with a rongeur (TECH FIG 1E), including the posterior capsule.

 

Use the measuring gauge to determine the size of the implant. In doubt (eg, if the anterior border of the tibia is projected onto the gauge between two markers), select the bigger size.

 

73

 

 

 

TECH FIG 1 • Tibial resection. Tibial resection block is adjusted taking the tibial tuberosityor the anterior spina of iliac crest as the reference in the frontal plane (A,B) and the anterior tibia in the sagittal plane (C). D. Two to 3 mm of bone is removed, as measured at the apex of the tibial plafond. E. Bone is removed and resection is finalized at the lateral side, paying attention not to damage the integrity of the fibula and at the medial side to get a sharp perpendicular cut along the medial malleolus.

Talar Resection

Positioning the Resection Block

 

Insert the talar resection block into the tibial cutting block.

 

Move the resection block as far distal as possible to properly tension the collateral ligaments (TECH FIG 2A).

 

Remove all distractors and spreaders before the foot is moved to a neutral position (eg, with respect to dorsiflexion-plantarflexion and pronation-supination).

 

Once the foot is in a neutral position, fix the resection block with two pins (medially and laterally) (TECH FIG 2B,C).

Making the Cuts

 

Resect the talar dome with the oscillating saw through the slot of the talar cutting block.

 

Remove the tibial and talar resection block and again mount the distractor (Hintermann spreader) to distract the joint.

 

Remove the posterior capsule completely until fat tissue and tendon structures are visible to achieve full dorsiflexion.

 

Insert the 12-mm thick spacer representing the thickness of the tibial and talar components and the thinnest 5-mm inlay into the created joint space (TECH FIG 2D). While the foot is held in neutral flexion position, the surgeon should check the following:

 

 

Whether an appropriate amount of bone has been resected Whether the achieved alignment is appropriate

 

Whether the medial and lateral stability are ensured

 

If the spacer cannot be properly inserted into the joint space and if there is no obvious contracture of the remaining posterior capsule present, additional bony resection might be considered. In most instances, such additional resection should be done on the tibial side. Reposition the tibial cutting block using the same fixation holes for the pins. Move the distal resection block proximally as desired and make a new cut with the saw blade.

 

If the alignment is not appropriate and if an associated deformity of the foot itself (eg, varus, valgus heel) can be excluded, consider a corrective cut. In most instances, the resection should be done on the tibial side. Make the desired angular correction on the tibial resection block and reposition the tibial cutting block using other fixation holes for the pins. Move the distal resection block proximally or distally so that an angular bony resection will result.

 

If the ankle is not stable on both sides, consider using a thicker inlay. If the ankle is not stable on one side, consider a release of the contralateral ligaments or ligament reconstruction on the

 

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affected side. Ligament reconstruction should be done once the definitive implants have been inserted and an obvious instability still exists.

 

 

 

TECH FIG 2 • Talar resection. A. After insertion of talar resection block, the whole block is moved distally until collateral ligaments of the ankle are fully tensioned. B. The talar resection block is fixed by pins to the talus while the foot is held in a neutral position. C. Alignment of the hindfoot is carefully checked. D. After the horizontal cut is made by the saw through the slot and the resection block is removed, the spacer is inserted to check alignment and stability of the ankle. E. The appropriate size of the talar resection block is fitted to the bone using the medial border of the talus as a reference. F. After posterior, medial, lateral, and anterior cuts are made, the block is removed. G. Bone stock of the talus after careful débridement of the medial, lateral, and posterior compartment as well as complete resection of the posterior capsule of the ankle joint.

 

 

 

Remove the spacer and mount the distractor (Hintermann spreader) using the same pins. Determine the size of the resected talar block as following (TECH FIG 2E):

 

Use the medial side of the talus as the reference; position the resection block along the medial border of the talus so that 1 to 2 mm of bone will be removed from the medial side of the talus.

 

On the lateral side, the resection block is supposed to remove as little bone as possible on its posterior aspect; usually, more bone will need to be removed on the lateral aspect of the talus, as osteophytes are more common there.

 

On the posterior side, the resection block is supposed to remove 2 to 3 mm of bone in addition to the remaining cartilage; this is given by the distance of the posterior hooks of the resection block that aim to

be in strong contact with the posterior surface of the talus.

 

The talar size should not exceed the previously determined tibial component by more than one size; if so, a smaller talar size must be selected.

 

After selecting the appropriate size of the talar cutting block, fix it with two or three short pins.

 

Perform the posterior resection of the talus with an oscillating saw that is guided through the posterior slot of the talar cutting block.

 

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Perform the medial and lateral resections of the talus with a reciprocating saw that is guided along the talar cutting block. Make the cut as following:

 

 

Medial side: 6 mm deep; the reference is the upper surface of the talus Lateral side: 8 mm deep; the reference is the upper surface of the talus

 

Perform the anterior resection of the talus with a drill that is guided through the anterior slot of the talar cutting block.

Finishing the Resection

 

Remove the talar cutting block (TECH FIG 2F).

 

On the medial and lateral sides, the cuts are finalized by using a chisel to make an almost horizontal cut along the base of the cuts previously made, thereby avoiding extended loss of bone stock and potential damage to the vascular supply of the talus.

 

Clean the medial and lateral gutters using a rongeur.

 

Remove the remaining bone and capsule of the posterior compartment (TECH FIG 2G).

• Inserting Trial Implants and Finalizing Cuts

   

  Talar trial

   

  Insert the talar trial using the given impactor. The window on the posterior aspect of the trial allows the surgeon to check its proper fit to the posterior resection surface of the talus (TECH FIG 3A).

   

  If proper position of the talus has been achieved, resect the anterior surface of the talus using a rongeur or the oscillating saw.

   

  Fix the drill guide onto the talar trial (TECH FIG 3B).

   

   

   

  TECH FIG 3 • Trial implants. A. First, the trial implant of the talus is inserted, paying attention to obtain a proper fit to the posterior resection surface. B. After resection of anterior surface, the bloc is inserted and the holes for the pegs are drilled. C. The talar trial is removed. The resection surfaces of the talus and tibia are carefully checked for cyst formation. If present, they are meticulously removed. D. The tibial depth gauge is inserted and the size of tibial implant is determined. E. The tibial trial implant is inserted making sure that the tibial component is in close contact with the medial malleolus and the anterior surface of tibia. If necessary, the anterolateral tibia has to be smoothed.

   

   

  Make two drill holes with the provided 4.5-mm drill and remove the trial (TECH FIG 3C).

   

  Tibial trial

   

  Use the tibial depth gauge to determine the size of the tibial implant to be selected; insert it with the appropriate side (right/left) against the tibial surface and hook the posterior edge on the posterior border of the tibia. The size that should be selected can be taken from the scale on the depth gauge (TECH FIG 3D).

   

  Remove the depth gauge and, if necessary, smooth the anterior border of the tibial resection with an oscillating saw or rongeur according to the shape of the indicated resection.

   

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  Insert the tibial trial. Try to get the tibial component in close contact with the medial malleolus and the anterior surface of tibia (TECH FIG 3E).

   

  Trial inlay: Insert the 5-mm inlay trial and remove the distractor (Hintermann spreader); if not enough soft tissue tension can be achieved, insert the 6-, 7-, or 9-mm trial.

   

  The use of fluoroscopy is highly recommended to check the position of implants while the foot is held in neutral position, particularly the following:

   

  Appropriate length of the tibial component: Its posterior border should be in line with the posterior aspect of the tibia so that the tibial surface is fully covered.

   

  Proper fit of the tibial component to the tibial surface

   

  Proper fit of the posterior edge of the talar component to the posterior surface of the talus

   

  Point of contact of the talar component to the tibial component. This contact point should be between 40% and 45% of the tibial component when the anterior border is taken as 0% and the posterior border as 100%, respectively. If the point of contact is too posterior, ligament balance will not be achieved.

   

  Carefully check the bony surfaces. Any cysts need to be removed with a curette; furthermore, filling with cancellous bone taken from the removed bony material is recommended. If there is sclerotic bone left on the surface, drilling with a 2.0-mm drill is recommended.

• Insertion of Implants

   

  Insert the final implants previously selected as follows:

   

  Fill the talar component with bone matrix (IsoTis) to get the cysts filled and then insert the talar component so that the pegs can glide into the two drilled holes; use a hammer and impactor to obtain a proper fit of the component to the bone (TECH FIG 4A).

   

  Insert the tibial component along the medial malleolus until proper fit to the anterior border of the tibia is achieved (TECH FIG 4B).

   

  Insert the inlay (same size as the talar component). Remove the distractor (Hintermann spreader). Hammer and impactor might be used for appropriate fit to the bone (TECH FIG 4C).

   

  Check stability and motion clinically.

   

   

   

  TECH FIG 4 • Insertion of definitive implants. A. The talar component is impacted first. B. After insertion of the tibial component and the polyethylene insert (C), the tibial component is impacted to obtain a proper fit to the tibial resection surface. D. The foot is moved in dorsiflexion with the surgeon's maximal power, hereby settling of the implant might be improved and remaining soft tissue contracture on the posterior aspect of the ankle might be released. (continued)

   

   

  While the foot is moved in dorsiflexion with the surgeon's maximal power, settling of the implant might be improved and remaining soft tissue contracture on the posterior aspect of the ankle might be released (TECH FIG 4D).

   

  Screw fixation of the tibial component may be considered to achieve stability against rotational and translational forces during the osteointegration process; however, this is seldom necessary, as proper fit and the pyramidal peaks usually provide sufficient primary stability.

   

  It is furthermore highly recommended to check the position of the implants by fluoroscopy, as described earlier for the trial implants (TECH FIG 4E,F). This allows the surgeon to detect any remaining bony fragments or osteophytes that could be a potential source of pain or motion restriction.

   

  77

   

   

   

  TECH FIG 4 • (continued) E. Final check of the position of the implants using fluoroscopy. On the AP view, the surgeon checks the position of the implants for any misalignment that may cause edge load of the polyethylene insert, overall alignment in the frontal (coronal) plane, distraction of the ankle (gap between the fibula and talus), and medial and lateral gutters for any bone left that may cause bony impingement. F. On the lateral view, the surgeon checks the position of the implants with regard to the bone surfaces (proper fit) and alignment of the implants with regard to contact area (usually, the apex of the talar component should meet the tibial component 3 to 5 mm anterior to its midpoint).

• Wound Closure

   

  The wound is closed by suturing the tendon sheath, the retinaculum (TECH FIG 5A), and the skin (TECH FIG 5B).

  Dress the wound, taking care to avoid any pressure to the skin (TECH FIG 5C).

   

  TECH FIG 5 • Wound closure and dressing. A. The extensor retinaculum is closed first. B. Then, the skin is closed by interrupted sutures. C. A compressive dressing is used to avoid swelling and hematoma formation. D. A splint is used to keep the foot in neutral position.

  A splint is used to keep the foot in neutral position (TECH FIG 5D).

   

   

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  PEARLS AND PITFALLS
  	Malalignment or malunion above the ▪ Above the ankle joint ankle joint

  • Supramalleolar osteotomy

  • At the ankle joint

    • Corrective tibial cut

    • Osteotomy of fibula or medial malleolus

  • Beneath the ankle joint

    • Calcaneal osteotomy

   

   

   

   

  Adjacent osteoarthrosis

  • Subtalar joint

     

    • Subtalar arthrodesis

       

  • Talonavicular joint

     

     

     

    • Talonavicular arthrodesis

 

Fixed deformity ▪ Valgus deformity   Triple arthrodesis Medial sliding osteotomy of calcaneus   Varus deformity   Release of medial ankle ligaments Reconstruction of lateral ankle ligaments Peroneus longus to brevis tendon transfer Lateral sliding osteotomy of calcaneus Dorsiflexion osteotomy of first ray

Ligamentous instability ▪ Lateral ankle ligaments   Lateral ligament reconstruction   Medial ankle ligaments   Tibiotalar tilt of less than 10 degrees: medial ligament reconstruction Tibiotalar tilt of more than 10 degrees: ankle arthrodesis

Muscular dysfunction ▪ Peroneus brevis   Peroneus longus to brevis tendon transfer   Tibialis posterior   Triple arthrodesis

 

POSTOPERATIVE CARE

 

The wound dressing and splint are removed and changed after 2 days.

 

When the wound is dry and proper, typically 2 to 4 days after surgery, the foot is placed in a stabilizing cast or walker that protects the ankle against eversion, inversion, and plantarflexion movements for 6 weeks.

 

Active motion and lymphatic drainage may support recovery of the soft tissues during the first 6 weeks. However, overly aggressive motion during the first postoperative days may lead to breakdown of soft tissues.

 

Weight bearing is allowed as tolerated. Usually, full weight bearing is achieved after 1 week.

 

In the case of additional osteotomies of the calcaneus, ligament reconstruction, or tendon transfer, cast immobilization for 6 weeks is advised.

 

In case of an additional fusion of adjacent joints, cast immobilization for 8 weeks is advised.

 

In case of an additional supramalleolar osteotomy, the patient should remain non-weight bearing for 8 to 10 weeks.

 

A rehabilitation program should be started for the foot and ankle after cast or walker removal, including stretching and strengthening of the triceps surae.12

 

First clinical and radiologic follow-up is done at 6 weeks to check the wound site, osteointegration, and position of the implants.

 

The patient is advised to wear a compression stocking for a further 4 to 6 months to avoid swelling.

 

 

OUTCOMES

Between May 2000 and December 2012, 919 primary total ankle arthroplasties were performed in 866 patients (411 women, 455 men; mean age 61.3 ± 12.6 years [range 19.8 to 90 years]; left side 435, right side 484). The underlying diagnosis was posttraumatic osteoarthritis in 696 ankles (75.7%), primary osteoarthritis in 97 ankles (10.6%), inflammatory arthritis in 99 ankles (10.8%), and other secondary osteoarthritis in 27 ankles (2.9%).

The mean follow-up was 4.3 ± 2.9 years (range 1 to 13 years). The mean American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score improved from 43.6 ± 17.3 preoperatively to 74.5 ± 18.5 postoperatively and the mean pain relief (Visual Analog Scale [VAS] for pain) was from 6.7 ± 1.8 preoperatively to 2.5 ± 2.4 postoperatively. The mean plantar flexion at latest follow-up was 27.0 ± 9.3 degrees and the mean dorsiflexion was 7.6 ± 6.6 degrees. The satisfaction grade was excellent in 34.7%, good in 29.5%, and moderate in 15.3%; only 5.5% were dissatisfied.

Early complications included malleolar fractures intraoperatively, 30 ankles (3.3%); wound healing problems, 42 ankles (4.6%); infection, 38 ankles (4.1%); and polyethylene dislocation, 14 ankles (1.5%).

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Late complications included loosening of components, 56 ankles (6.1%); polyethylene dislocation, 14 ankles; polyethylene wear, 8 ankles; progressive loss of motion, 18 ankles; chronic pain syndrome, 20 ankles.

Taking revision of a metallic implant or conversion into ankle arthrodesis as the end point, overall survivorship of both components at 10 years was 84% (88% for the talar component and 89% for the tibial component).

Eighty-two ankles were revised to total ankle arthroplasty or to ankle arthrodesis (component loosening, 56; cyst formation, 9; pain/arthrofibrosis, 7; infection, 11).

 

COMPLICATIONS

Intraoperative complications2,3,4,5

 

Malpositioning of prosthetic implant Improper sizing of prosthetic implant Fractures of malleoli

Tendon injuries

Postoperative complications2,3,4,5 Wound healing problems Infection

Swelling

Deep venous thrombosis Late complications2,3,4,5

Aseptic loosening

Subsidence Polyethylene wear

Dislocation of polyethylene bearing Progressive loss of motion

 

 

REFERENCES

1. Barg A, Zwicky L, Knupp M, et al. HINTEGRA total ankle replacement: survivorship analysis in 684 patients. J Bone and Joint Surg Am 2013;95(13):1175-1183.

    

    

2. Haddad SL, Coetzee JC, Estok R, et al. Intermediate and long-term outcomes of total ankle arthroplasty and ankle arthrodesis. A systemic review of the literature. J Bone Joint Surg Am 2007;89(9):1899-1905.

    

    

3. Henricson A, Skoog A, Carlsson A. The Swedish ankle arthroplasty register: an analysis of 531 arthroplasties between 1993 and 2005. Acta Orthop 2007;78:569-574.

    

    

4. Hintermann B, Valderrabano V, Dereymaeker G, et al. The HIN-TEGRA ankle: rationale and short-term results of 122 consecutive ankles. Clin Orthop Relat Res 2004;(424):57-68.

    

    

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