Salvage arthrodesis after failed ankle replacement: surgical decision making

Tibiotalocalcaneal Arthrodesis with Structural Allograft for Management of Large Osseous Defects of the Hindfoot and Ankle: A Systematic Review and Meta-Analysis

Large osseous defects of the hindfoot and ankle pose a surgical challenge. Tibiotalocalcaneal (TTC) arthrodesis utilizing a structural allograft may be required to fill the osseous void, preserve limb length and achieve fusion. Several authors have reported small case series on this topic, however outcomes have varied and no systematic review of this data has been published to date. The primary aim of this study is to report rates of osseous union, limb salvage and complications in patients undergoing TTC arthrodesis with a structural allograft. A total of 11 publications were identified that met the inclusion criteria. One hundred seventy-five patients were included with a weighted mean age of 60.5 (range 50-72) years and follow-up period of 29.7 (range 3-62) months. Femoral head allograft was the most commonly utilized structural graft and a retrograde intramedullary nail was the most common fixation construct. Results demonstrated an overall union rate of 67.4%, limb salvage rate of 92.5% and complication rate of 26.6%. Allograft-related complications were rare with an allograft fracture rate of 0.1% and allograft collapse rate of 1.2%. There was no significant difference in union rate when using a retrograde intramedullary nail versus a plate construct (p = .9148). TTC arthrodesis with use of a structural allograft is a viable treatment option for limb salvage when faced with complex hindfoot and ankle pathology involving large osseous defects. Despite high rates of radiographic nonunion, this approach can provide patients with a stable and functional limb while avoiding amputation.

Finite-element analysis of the influence of tibial implant fixation design of total ankle replacement on bone-implant interfacial biomechanical performance

PURPOSE

Implant loosening in tibia after primary total ankle replacement (TAR) is one of the common postoperative problems in TAR. Innovations in implant structure design may ideally reduce micromotion at the bone-implant interface and enhance the bone-implant fixation and initial stability, thus eventually prevents long-term implant loosening. This study aimed to investigate (1) biomechanical characteristics at the bone-implant interface and (2) the influence of design features, such as radius, height, and length.

METHODS

A total of 101 finite-element models were created based on four commercially available implants. The models predicted micromotion at the bone-implant interface, and we investigated the impact of structural parameters, such as radius, length, and height.

RESULTS

Our results suggested that stem-type implants generally required the highest volume of bone resection before implantation, while peg-type implants required the lowest. Compared with central fixation features (stem and keel), peripherally distributed geometries (bar and peg) were associated with lower initial micromotions. The initial stability of all types of implant design can be optimized by decreasing fixation size, such as reducing the radius of the bars and pegs and lowering the height.

CONCLUSION

Peg-type tibial implant design may be a promising fixation method, which is required with a minimum bone resection volume and yielded minimum micromotion under an extreme axial loading scenario. Present models can serve as a useful platform to build upon to help physicians or engineers when making incremental improvements related to implant design.

Effect of bone morphogenetic protein-2/hydroxyapatite on ankle fusion with bone defect in a rabbit model: a pilot study

Background

Revision ankle-fusion surgery after a failure of total ankle arthroplasty has a problem with bone-defect management by implant removal. For the reconstruction of bone defects, autogenous bone often causes minor and major complications. Recombinant human-bone morphogenetic protein-2 (rhBMP-2) plays essential roles in bone regeneration strategies, and hydroxyapatite (HA) is beneficial as the rhBMP-2 carrier. In this study, we evaluate whether rhBMP-2/HA can replace autogenous bone in a rabbit ankle-fusion model with distal tibia bone defect.

Methods

The bone defect was created in the distal tibia. The ankle fusion was performed by a cannulated screw from lateral malleolus and various treatments on bone defect. Thirty male white New Zealand rabbits were divided into three groups of 10 animals on each group dependent on treatment methods as control group (no treatment into defect), auto-bone group (autogenous bone treatment), and rhBMP-2/HA group (40 μL of 1 μg/mL rhBMP-2/100 μL HA). Bone formation on defect and the union of the ankle joint were evaluated by X-ray, micro-CT, and histological analysis at 8 weeks and 12 weeks, postoperatively.

Results

Radiographic assessment found the control and auto-bone groups still had the bone defect present, but rhBMP-2/HA group showed complete replacement of the defect with newly formed bone at 12 weeks. Micro-CT showed significantly higher new bone formation within the defect in the rhBMP-2/HA group than in the auto-bone and control groups at 8 weeks (p > 0.05 and p < 0.01, respectively) and 12 weeks (p < 0.05, p < 0.001, respectively). Fusion rate (%) analysis of micro-CT showed a higher percentage of union in the rhBMP-2/HA group than in the auto bone and control groups at 8 weeks (p > 0.05, p < 0.001, respectively) and 12 weeks (p < 0.001 and p < 0.001, respectively). The histological showed the highest osteointegration between distal tibia and talus in the rhBMP-2/HA group at 12 weeks.

Conclusions

This study indicated that rhBMP-2/HA showed much better bone fusion than did the autogenous bone graft and was effective in promoting fusion rate and improving the quality of the ankle joint fusion.

Distal tibial distraction osteogenesis-an alternative approach to addressing limb length discrepancy with concurrent hindfoot and ankle reconstruction

Background

Limb length discrepancy (LLD) in the setting of concurrent hindfoot and ankle deformity poses an added level of complexity to the reconstructive surgeon. Regardless of etiology, a clinically significant LLD poses additional challenges without a forthright and validated solution. The purpose of the current study is to determine whether reconstructive hindfoot and ankle surgery with concurrent lengthening through a distal tibial corticotomy is comparable to other treatment alternatives in the literature.

Patients and methods

A retrospective review of hindfoot and ankle deformity correction utilizing Ilizarov circular external fixation with concurrent distal tibial distraction osteogenesis from July 2009 to September 2014 was conducted.

Results

This study included 19 patients with a mean age of 47.47 ± 13.36 years with a mean follow up of 576.13 ± 341.89 days. The mean preoperative LLD was 2.70 ± 1.22 cm and the mean operatively induced LLD was 2.53 ± 0.59 cm. The mean latency period was 9.33 ± 3.47 days and distraction rate was 0.55 ± 0.16 mm/day. The mean distraction length was 2.14 ± 0.83 cm and mean duration of external fixation was 146.42 ± 58.69 days. The time to union of all hindfoot and ankle fusions was 121.00 ± 25.66 days with an overall fusion rate of 85.71%.

Conclusions

The successful treatment of hindfoot and ankle deformity correction in the setting of LLD using the technique of a distal tibial corticotomy and distraction osteogenesis is reported and illustrates an additional treatment technique with comparable measured outcomes to those previously described. We urge that each patient presentation be evaluated with consideration of all described approaches and associated literature to determine the current best reconstructive approach as future studies may validate or replace the accepted options at present.

Tibiotalocalcaneal arthrodesis with distal tibial allograft for massive bone deficits in the ankle

BACKGROUND

The purpose of this study was to assess the outcomes of distal tibial structural allograft to obtain a stable TTC fusion.

METHODS

Retrospectively, ten patients were carried out with a minimum one year follow-up. The median age was 72 (33-81). The median BMI was 28 (24-33). Indications for TTC arthrodesis included failed total ankle arthroplasty (n=7 patients), prior nonunion (n=2 patients), and a trauma injury.

RESULTS

Union rate was 80%. The median initial height of the distal tibial allograft was 19mm (14-24mm). In seven cases the allograft did not lose height. The AOFAS score median was 69 (31-84). SF-12 median physical component was 39 (30-53), and 59 (23-62) for mental component. The VAS median was 2 (0-8).

CONCLUSIONS

TTC using distal tibial allograft shows a lower rate of collapse than other structural grafts and provides a fusion rate higher or in accordance with the literature.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Salvage arthrodesis of a failed total ankle replacement using a custom 3D-printed cage implant: A case report and review of the literature

We present a case report of a 66-year-old female who underwent salvage arthrodesis after a failed Scandinavian Total Ankle Replacement secondary to aseptic loosening and talar subsidence. Secondary to the loss of talar integrity the decision was made to proceed with revisional ankle arthrodesis. To maintain limb length the primary surgeon (EH) elected to use a custom cage implant in combination with an intramedullary nail construct in a single stage approach. The custom cage was augmented with autograft & allograft cancellous bone in addition to allograft recombinant human bone morphogenic protein, and allograft adult mesenchymal stem cells. The incision sites healed post-operatively without incident and at post-op week 16 the patient progressed to full unrestricted weight bearing in normal shoe wear with a gauntlet ankle brace. Although an isolated report, this case shows promise for further development of the technique. We believe this revisional arthrodesis technique warrants further research and consideration as a potential addition to the failed total ankle arthroplasty treatment algorithm.

Variable Volumes of Resected Bone Resulting From Different Total Ankle Arthroplasty Systems

BACKGROUND

The increased popularity and success of total ankle arthroplasty (TAA) has resulted in the development of varying TAA hardware designs, many of which include specific bone-sparing or bone-sacrificing features. The goal of this work was to determine differences in the volume of bone removed for implantation of different total ankle arthroplasty hardware systems.

METHODS

Sixteen cadaveric specimens were computed tomography-scanned preoperatively and after total ankle arthroplasty using either an INBONE II, Salto Talaris, STAR, or Zimmer TMTA implant. Geometries of the talus and the distal tibia were manually segmented and converted to 3D bony surface models. The volume of bone removed for each implant was calculated as the difference in volume between the preoperative and postoperative bone models. To account for differences in specimen size, volume was expressed as a percentage of the intact bone.

RESULTS

There was a significant difference (P = .049) in the average percent of talar bone removed, with the STAR and INBONE II systems requiring removal of greater volumes of bone. The INBONE II system required significantly (P < .004) more tibial bone resection than the other 3 implants when evaluating a long span of the distal tibia. However, most of this increased bone resection was medullary bone. Close to the articular surface, bone volumes removed for the various tibial components were not significantly different (P = .056).

CONCLUSION

Volume and location of bone removed for different implant systems varied with implant design.

CLINICAL RELEVANCE

Primary bone resection associated with different implant hardware systems varied more on the talar side of the articulation, and the stemmed prosthesis did not result in dramatic increases in periarticular bone resection. Clinicians should weigh the effects of greater or lesser bone resection associated with various implant designs against other factors used for hardware selection.

Salvage of Failed Total Ankle Replacement Using a Custom Titanium Truss

Subsidence of the talar component results in significant morbidity after total ankle replacement. When recognized, prompt revision could be needed to preserve the function of the implant; however, this is not always the case. In situations in which the implant cannot be revised, tibiotalocalcaneal arthrodesis might be necessary to salvage the extremity. The purpose of the present report is to describe the use of a custom titanium alloy truss to fill a bony void created by explantation of the implant components. Total ankle replacement was performed as the initial surgery to address end-stage osteoarthritis. Two years after the index procedure, the patient underwent revision of the polyethylene and talar components with subtalar arthrodesis secondary to progressive subtalar osteoarthritis and talar subsidence. The implant subsequently became infected and was removed. The patient underwent re-implantation after the infection had resolved, but significant talar subsidence required conversion to a tibiotalocalcaneal arthrodesis with a custom titanium alloy truss and retrograde intramedullary nail. At the most recent follow-up appointment, the patient was weightbearing on a stable extremity and pain free. Radiographic examination confirmed appropriate implant alignment and evidence of bone formation throughout the titanium truss. Although our results are restricted to a single case with initial, limited follow-up data, combining sound structural mechanics with an open architecture and unique texture, the custom titanium truss appears to maintain the limb length and promote healing across a large void.

Ankle arthrodesis after failed total ankle replacement: a systematic review of the literature

PURPOSE

As the number of total ankle replacements (TARs) performed has risen, so has the need for revision. The purpose of this investigation was to perform a systematic review of clinical outcomes following a salvage ankle arthrodesis from a failed TAR to identify patient- and technique-specific prognostic factors and to determine the clinical outcomes and complications following an ankle arthrodesis for a failed TAR.

METHODS

We searched PubMed, Medline, EMBASE, and the Cochrane Central Register of Controlled Trials for studies that analyzed ankle fusion after failed TAR with a minimum follow-up of 1 year.

RESULTS

We included 16 studies (193 patients). The majority of patients (41%) underwent the index TAR for rheumatoid arthritis. The majority of these revision surgeries were secondary to component loosening, frequently of the talar component (38%). In the cases that were revised to an ankle arthrodesis, 81% fused after their first arthrodesis procedure. The intercalary bone graft group and the blade plate group had the highest rate of fusion after the first attempt at fusion at 100%, whereas the tibiotalocalcaneal fusion with cage group had the lowest fusion rate at 50%. The overall complication rate was 18.2%, whereas the overall nonunion rate was 10.6%.

CONCLUSION

A salvage ankle arthrodesis for a failed TAR results in favorable clinical end points and overall satisfaction at short-term follow-up if the patients achieve fusion. The bone graft fusion and blade plate group resulted in the highest first-attempt fusion rate, with a low complication rate. Future studies should include prospective, comparative control or surgical groups and use standardized outcome measurements that will make direct comparisons easier.

LEVELS

Level IV: Systematic Review of Level IV Studies.

Use of a spinal cage for creating stable constructs in ankle and subtalar fusion

In complicated foot surgery with reconstruction of the hindfoot, a gap will sometimes be present between the bones that must be filled and stabilized. Bone grafting with structural bone graft is 1 alternative; however, it can collapse and must be stabilized with screws or a nail. A locking intramedullary nail can be used but could lead to nonunion owing to distraction. Newer nails include a compression device but that can result in shortening. We developed a technique that includes distraction of the fusion area with a spinal cage and then compression of the construct by inserting a compression screw through the cage. We present our experience with this technique.We reviewed the data from 7 patients who had undergone surgery using this technique. The technique included distraction of the fusion area and insertion of a titanium cylindrical spinal cage filled with autologous cancellous bone graft. A cannulated compression screw was then inserted through the cage, creating compression of the fusion area against the cage and achieving stabilization of the fusion area. Postoperatively, a non-weightbearing cast was applied for 3 months, followed by a full weightbearing cast until radiographic fusion was apparent. Complete radiographic union was observed in all 7 patients within 6 to 12 months postoperatively. At the latest follow-up visit, the mean American Orthopaedic Foot and Ankle Society scale score was 54 ± 16 (range 30 to 71) points. The use of a cylindrical titanium cage with a local bone graft and stabilization by distraction and compression provided a stable construct, avoided shortening, and led to good fusion. In addition, donor site complications and unpredictable strength loss and lysis of bone allograft were avoided.

Ankle fusion with a trabecular metal spacer and an anterior fusion plate

We present a novel operative technique for ankle joint fusion in a case of severe talar bone loss. Fusion was achieved with a trabecular metal spacer combined with a single anterior, anatomically preshaped, angular, stable plate. Excellent postoperative results with good bone consolidation and preservation of lower leg length were present shown at 1 year of follow-up.

Commercially available trabecular metal ankle interpositional spacer for tibiotalocalcaneal arthrodesis secondary to severe bone loss of the ankle

Retrograde tibiotalocalcaneal nailing arthrodesis has proved to be a viable salvage procedure; however, extended bone loss around the ankle has been associated with high rates of nonunion and considerable shortening of the hindfoot. We present the surgical technique and the first 2 cases in which a trabecular metal™ interpositional spacer, specifically designed for tibiotalocalcaneal nailing arthrodesis, was used. The spacer can be implanted using either an anterior or a lateral approach. An integrated hole in the spacer allows a retrograde nail to be inserted, which provides excellent primary stability of the construct. Trabecular metal™ is a well-established and well-described material used to supplement deficient bone stock in surgery of the spine, hip, and knee. It has shown excellent incorporation and reduces the need for auto- and allografts. The trabecular metal™ interpositional ankle spacer is the first trabecular metal spacer designed specifically for ankle surgery. Its shape and variable size will make it a valuable tool for reconstructing bone loss in tibiotalocalcaneal nailing arthrodesis.

Management of failures of total ankle replacement with the agility total ankle arthroplasty

BACKGROUND

Few studies have focused on treatment following failed total ankle replacement. The purpose of this study was to report the outcomes of patients undergoing revision total ankle replacement and to propose a talar component subsidence grading system that may be helpful in making decisions regarding how to revise failed total ankle replacements in the future.

METHODS

A retrospective review was performed of fifty-three patients who underwent revision total ankle replacement and had been followed for a minimum of two years. Patients were assessed radiographically and with outcome scores. The rates of conversion to amputation or fusion were also assessed.

RESULTS

The mean follow-up period was 49.1 months after the revision arthroplasty. The average time from primary total ankle replacement to revision was fifty-one months. Forty-one of the fifty-three patients (77%) were available for follow-up. The revision arthroplasty had been converted to an arthrodesis in five of the forty-one patients, and two additional patients had undergone amputation. The most common indication for revision total ankle replacement was talar subsidence (63%; twenty-six of forty-one). Twenty-two patients (54%) had a subtalar arthrodesis performed at the time of the revision arthroplasty, with nineteen of those having a custom-designed long-stem talar component placed simultaneously. The mean radiographic measurements of component position did not change significantly postoperatively. The mean postoperative scores for the thirty-four patients with a retained total ankle replacement were: 4.4 of 10 possible points on a visual analog pain scale (VAS), 65 of 100 possible points on the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot scale, 93.5 of 100 possible points on the Short-Form 12 (SF-12), 137.9 of 204 possible points on the Revised Foot Function Index (FFI-R), and 64 of 180 possible points on the Ankle Osteoarthritis Scale (AOS). The mean arc of motion radiographically was 18° preoperatively and 23° postoperatively, with all improvement occurring in plantar flexion. A lesser amount of preoperative talar subsidence was a significant predictor of a good outcome based on the AOFAS hindfoot score (p < 0.03) and the AOS (p < 0.01) score.

CONCLUSIONS

Revision arthroplasty may be considered as an alternative to arthrodesis when treating patients with a failed Agility total ankle implant.

The bright future for total ankle replacements

Total ankle arthroplasty is an evolving method of treatment for end-stage ankle arthritis. Although historic interest did not yield favorable results, new generation total ankle implants have demonstrated comparable results with fusion with short- and intermediate-term follow-up. Comparable outcomes, in the setting of improving surgical technique and implant options, will yield increasingly superior results.