Revisional Surgery for Total Ankle Replacements

Thomas S. Roukis, Jason Piraino

Introduction

Total ankle replacement (TAR) is a demanding procedure that frequently fails for multiple reasons prompting revision. Henricson et al ¹ set forth the specific definitions for secondary procedures performed for failed TAR. These are (1) revision, defined as any removal or exchange of 1 or more of the metallic prosthesis components except for incidental exchange of the ultrahigh-molecular-weight polyethylene (PE) insert (ie, metallic component replacement, custom-design prosthesis utilization, ankle or tibiotalocalcaneal (TTC) arthrodesis, or below-the-knee amputation); (2) reoperation, defined as nonrevisional secondary surgery involving the joint (ie, debridement, incidental PE insert exchange, or wound treatment); and (3) additional procedure, defined as nonrevisional secondary surgery not involving the joint (ie, ligament reconstruction/release, tendon lengthening/transfer, adjacent joint arthrodesis, and/or periarticular osteotomy). Intraoperative complications (ie, malleolar fracture, nerve or tendon injury) and incision healing-related problems (ie, wound coverage, infection) associated with TAR have received the bulk of attention. However, management of the intermediate and long-term complications (ie, aseptic osteolysis, subsidence, component loosening and progressive malalignment) remains limited, with the potential need to revise previously revised TARs.² ^–⁹ The development of aseptic osteolysis following TAR is the major cause of failure, increases with time, and results in loss of fixation of the prosthetic components.¹⁰ This process involves a macrophage-mediated osteolytic destruction of periprosthetic bone secondary to phagocytosable PE wear debris usually secondary to prosthetic component malposition.¹⁰ ^–¹⁷

The only readily available revision prostheses in the United States are the Invision Total Ankle Revision System (Wright Medical Technology, Memphis, TN/Stryker, Kalamazoo, MI) and the Salto Talaris XT Revision Total Ankle Replacement System (Integra, Austin, TX/Smith + Nephew, Cordova, TN). In addition, all of the available TAR systems in the United States have some version of thicker PE intended for revision situations. The temptation to use revision components for complex primary TAR situations exists and should be tightly regulated to avoid unnecessary use since future revision would be made more difficult if not impossible. Debate remains whether patients with failed primary TAR are best served with revision TAR¹⁸ ^–²⁷ or TTC arthrodesis²⁸ ^–³¹ most commonly employing bulk intercalary allograft, with trabecular metal spacers³² and 3-D printed metallic cages recently released for use. Revision TAR with the tibial and/or talar components supported by multiple metal-reinforced triangular rods/large-diameter screws³³ or coiled metallic wires³⁴^,³⁵ affixed within polymethylmethacrylate (PMMA) cement and permanent PMMA cement spacer³⁶ ^–³⁸ are feasible in situations where conversion to TTC arthrodesis is not possible and below-the-knee amputation is not desired.

Indications and Contraindications

At present there are no “standard principles” associated with revision TAR, and instead this is very much a concept in evolution.¹⁸ What is clear is that the current approaches are technically very complex, fraught with complications, and no one approach represents the only answer.

One option incudes exchange of TAR metallic components to the same or similar system standard or dedicated revision components.¹⁵^,¹⁶^,¹⁸^,²⁰ ^–²⁵^,²⁷^,³⁹ ^–⁴¹ This approach represents a straightforward, low-cost option with limited occurrence of complications and should be considered as the revision method of choice when feasible. This approach is indicated predominantly when the metallic prosthetic components are loose, bone loss is minimal, and alignment is appropriate or can be corrected with periarticular osteotomy, adjacent joint arthrodesis, and/or soft tissue balancing. Contraindications include excessive bone loss that would preclude metallic implant incorporation or exceeds the thickness limits of the metallic and PE prosthetic components and alignment that cannot be corrected with periarticular osteotomy, adjacent joint arthrodesis, and/or soft tissue balancing.

Explantation and conversion to custom-designed long-stemmed components with or without total talar body replacement has limited availability.⁴² ^–⁴⁵ Explantation and conversion to another TAR system is associated with significant intraoperative radiation exposure⁴⁶ and at present remains high risk with strong potential for complications.¹⁶^,¹⁹^,²⁰^,²⁵ ^–²⁸^,⁴⁷ ^–⁵⁰ The only readily available revision prostheses in the United States are the Invision Total Ankle Revision System and the Salto Talaris XT Revision Total Ankle Replacement System. In addition, the HINTEGRA Revision Ankle Prosthesis (Newdeal, Lyon, France/Integra, Plainsboro, NJ) is available for use outside the US market. These revision TAR systems have thicker tibial tray and PE intended for revision situations where vertical bone loss exists. The revision systems talar components have thicker components to compensate for bone loss, incorporate anterior fixation pegs in the dense talar neck cortical bone, as well as have wider and longer dimensions than the primary versions allowing broader coverage onto the surrounding bone surfaces. The temptation to use revision components for complex primary TAR situations exists⁴³ and should be tightly regulated to avoid unnecessary use since future revision would be made more difficult if not impossible.

Revision TAR with the tibial and/or talar components supported by multiple metal-reinforced triangular rods/large-diameter screws³³ or coiled metallic wires³⁴^,³⁵ affixed within PMMA cement and permanent PMMA cement spacer³⁶ ^–³⁸ is feasible in situations where conversion to TTC arthrodesis is not possible and below-the-knee amputation is not desired.

Detailed Surgical Technique

We employ a standardized approach to the management of each revision TAR, allowing for deviation and augmentation to this approach on an individual basis as clinically required. A thigh tourniquet is applied but not always inflated, and a gel roll is placed under the ipsilateral hip to control physiologic external rotation. The patient receives a musculoskeletal ultrasound-guided popliteal and saphenous nerve blockade by the anesthesiologist and is placed under general anesthesia with endotracheal intubation. We utilize a standard anterior ankle incision along the previous surgical incision, with careful soft tissue dissection to the level of the ankle joint capsule/scar, taking care to protect the anterior neurovascular bundle and maintain appropriate tissue planes for layered closure. Retraction is minimized to only what is necessary to aid in preservation of the tenuous anterior soft tissues. Following entry into the ankle joint space, evacuation of the PE wear debris is performed and this material is sent for histopathology. In addition, multiple deep cultures from the ankle joint tissues are procured for fresh frozen analysis and culture with sensitivities owing to the concern for indolent deep periprosthetic infection with revision joint replacements. The periosteal tissues are elevated directly off the bone overlying the tibial component and then the talar component. Soft tissue exposure is limited to only what is needed to visualize the metallic components along with the medial and lateral gutters. Once soft tissue dissection is completed, the PE insert is removed by prying it free from the undersurface of the tibial tray or utilizing the dedicated PE extractor for the TAR prosthesis undergoing explantation. The talar component is freed from ectopic bone growth and then gently pried free of the underlying bone with care taken not to fracture the talus during manipulation. Limited osseous on-growth to the talar component is usually appreciated in each revision surgery regardless of talar component prosthetic design; however, there is usually at least 1 area of the bone-prosthetic interface that demonstrates sound osseous integration. Accordingly, we recommend that great care be taken to liberate this region of the talar component free from the talar bone followed by careful manipulation of the talar component during extirpation.

In the case of talar component exchange with retention of the tibial component, the remaining talar bone surface is prepared for implantation of the new talar component with care taken to correct any preexisting osseous malalignment and to select the PE insert that will most appropriately tension the ankle joint ligamentous structures. This frequently involved redoing the talar fixation peg(s)/stem after correcting the rotation and anterior-posterior alignment of the talar component for optimum function.

In the event of explantation and conversion to a different TAR system, the appropriate technique per the specific TAR system is followed. For each revision, we choose to employ a thin layer of antibiotic-impregnated PMMA cement (Simplex P with Tobramycin, Stryker Orthopedics, Mahwah, NJ) about the perimeter of the replaced metallic components when good osseous apposition was possible. If an arthrodesis is performed, the appropriate technique per the specific TTC fusion nail or plate/screw system in employed.

It should be noted that, in order to reduce the potential for deep periprosthetic infection, traffic about and number of people in the operating room is kept to an absolute minimum. For the week immediately preceding the surgery, patients perform a daily 5-minute scrub of their surgical limb with chlorhexidine gluconate (4%) solution (Hibiclens, Regent Medical Americas, Norcross, GA). In addition, the author performs a validated surgical preparation involving the foot, ankle, and lower leg using a 3-minute scrub with foam sponges impregnated with chlorhexidine gluconate (4%) solution followed by painting with ethyl alcohol and iodine (1%) topical solution (1 g iodine/100 mL ethyl alcohol) (Spectrum Chemical Manufacturing Corporation, Gardena, CA).⁵¹ Furthermore, the toes are covered with an impermeable incise barrier, the exposed skin is intermittently repainted with Betadine Solution (10% povidone iodine solution, Purdue Products, LP, Stamford, CT), and the surgical site is serially irrigated with a pulsed lavage system impregnated with 50,000 IU Bacitracin solution (Pfizer, Inc, New York, NY) per 3-L bag. The operating rooms are all laminar flow systems without ultraviolet lights. Each member of the surgical team wears double surgical masks or a surgical hood/space suit based on personal protective equipment preference.

Meticulous, layered closure is essential. Every patient receives a surgical drain and an anterior windowed folded Webril Undercast Padding (Kendall-Coviden, Mansfield, MA) cutout to the anterior incision line with additional Sir Robert Jones compression dressing and posterior molded plaster splint. We have found that the anterior windowed folded Webril Undercast Padding limits contact pressure on the tenuous anterior incision and the Sir Robert Jones dressing affords edema reduction during the postoperative period.⁵² All patients follow our standard postoperative protocol for TAR, which includes hospital admission, 48 hours of intravenous antibiotic therapy with a first-generation cephalosporin, strict bed rest protocol with lower extremities elevated above heart level, and heels offloaded using pillow cocoon and a semi-Fowler bed positioning protocol.⁵³ Although anecdotal, supplemental oxygen via nasal cannula during the hospitalization is routinely employed as it may reduce incision and ischemia-related wound healing problems. The patients’ activities with physical and occupational therapy are advanced while maintaining strict non–weight-bearing to the operative lower extremity and discharge to home versus a skilled nursing facility proceeds. Patients are maintained on a strict mechanical and pharmacologic thromboembolic prophylaxis protocol until a return to full weight-bearing and activity is realized. At the 8-week follow-up appointment, weight-bearing ankle radiographs are obtained, and if no complications are noted, patients are permitted to transition into full weight-bearing and back into a supportive shoe or lace-up high-topped boot. Weight-bearing ankle radiographs are obtained including stress sagittal plane dorsiflexion and plantarflexion, as well as long leg axial views 1 year from the revision TAR and every year thereafter during the annual surveillance program we employ. Although controversial, dental antibiotic prophylaxis, use of a brace or lace-up high-topped boot with any exposure to uneven ground, and avoidance of ballistic activities is enforced lifelong.

Metallic Prosthetic Component Exchange Using the Same Total Ankle Replacement System Standard Components

The concept of tibial and/or talar metallic component exchange for revision of failed primary TAR is an established approach reserved for situations where 1 of the metallic components is well bonded to the adjacent bone and well aligned while the other is loose, subsided, malaligned or otherwise requires removal and revision replacement (Figures 29.1 –29.9). This approach represents a straightforward, low-cost option with limited occurrence of complications and should be considered as the revision method of choice when feasible.