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

Early results of combined total ankle total talus replacement in the revision setting

BACKGROUND

Revision of failed total ankle replacement (TAR) is challenging and associated with increased morbidity. Given the increased popularity of TAR in treating end-stage ankle arthritis (ESAA), viable revision options are needed. The objective of this case series is to present a minimum 2-year clinical and radiographic outcomes of patient-specific custom 3D-printed total ankle total talus (TATR) prostheses in this unique subset of patients.

METHODS

19 participants with ESAA and failed primary TAR who underwent TATR by a single surgeon at our institution from 2019 to 2021 were retrospectively identified. All participants were indicated for revision of primary STAR implant (Stryker, Kalamazoo, MI) and underwent replacement with 3D-printed titanium implants based on preoperative CT analysis (Additive Orthopaedics, Little Silver, NJ). Custom components included a mobile-bearing total talus and stemmed tibial system, performed through an anterior approach. Pre- and postoperative patient-reported outcomes were assessed using the Patient Reported Outcomes Measurement Information System (PROMIS). Pre- and postoperative implant alignment was assessed using medial distal tibial angle (MDTA) and tibiotalar angle (TTA) on anteroposterior, and sagittal tibial angle (STA) on lateral weight-bearing plain films.

RESULTS

The average patient age was 60.6 (range, 39-77) years, with an average follow-up of 37.9 (range, 25.3-57.5) months. There was statistically significant improvement in all PROMIS domains. Short-term survivorship was 100%, with two participants (11.0%) requiring reoperation for postoperative complications: one underwent open reduction internal fixation of the tibia for a periprosthetic fracture, and another underwent medial gutter debridement and tarsal tunnel release for recurrent pain. There were no significant differences in pre- versus postoperative radiographic alignment measured by MDTA (89.9 vs 86.4), TTA (89.7 vs 88.1), or STA (85.2 vs 85.3).

CONCLUSION

Custom 3D-printed TATR is a promising option for revision TAR. There was significant short-term improvement in pain and physical function, with excellent short-term survivorship and an acceptable postoperative complication rate.

The INVISION Talar Component in Revision Total Ankle Arthroplasty: Analysis of Early Outcomes

INTRODUCTION

Launched in 2018 for revision total ankle arthroplasty (rTAA), the INVISION talar component addresses subsidence when poor talar bone stock is present. Due to the recency of the market-availability of the INVISION, studies evaluating its efficacy are lacking. This study presents the first analysis of early-term outcomes of patients undergoing rTAA with the INVISION talar component.

METHODS

This was a single-center, retrospective review of 28 patients undergoing rTAA with the INVISION talar component and INBONE II tibial component performed between 2018 and 2022. Data on preoperative characteristics, postoperative complications, secondary procedures, and survivorship were collected. The primary outcome measures were rates of major complications, re-operation, and implant failure. Secondary outcomes included post-operative changes in varus and valgus alignment of the tibia and talus.

RESULTS

The most common secondary procedures performed with rTAA were medial malleolus fixation (n = 22, 78.6%) and gastrocnemius recession (n = 14, 50%). Overall, 10.7% (n = 3) of patients underwent reoperation and 14.3% (n = 4) suffered major complications. Incidence of implant failure was 10.7% (n = 3). All reoperations were caused by infection. Mean varus alignment of the tibia and talus improved from 4.07 degrees and 4.83 degrees to 1.67 degrees and 1.23 degrees, respectively. Mean valgus alignment of the tibia and talus improved from 3.67 degrees and 4.22 degrees to 2.00 degrees and 2.32 degrees, respectively.

CONCLUSIONS

In a series of 28 patients undergoing rTAA with the INVISION talar component, we discovered comparatively low rates of reoperation, major complication, and implant failure (10.7%, 14.3%, and 10.7%). The INVISION system appears to have a reasonable safety profile, but further studies evaluating long-term outcomes are required to assess the efficacy of the INVISION system.

Revision Total Ankle Arthroplasty Using a Novel Modular Fixed-Bearing Revision Ankle System

INTRODUCTION

Large bone defects such as those encountered after failed total ankle replacement have previously been a relative contraindication to revision ankle replacement due to inadequate bone stock. We describe our experience and patient reported outcomes with a modular ankle replacement system with tibial and talar augments.

METHODS

This is a retrospective case series analysis of patients who underwent a total ankle replacement using the INVISION system across 2 centers between 2016 and 2022. Patients completed the Manchester-Oxford Foot Questionnaire (MOXFQ), Ankle Osteoarthritis Scale (AOS), and EQ-5D pre-operatively and then post-operatively at 6 months, 1 year, 2 years, 3 years, and 5 years. Medical records were reviewed for complications and re-operations. X-rays were reviewed for lucencies and alignment.

RESULTS

A total of 17 patients were included in the study; 14 men and 3 women with an average age at the time of surgery of 67.9 years (range 56-80 years). The average follow-up post-operatively was 40.5 months (range 7-78) at the time of this study. The indication for surgery was revision of failed total ankle replacement (TAR) in 16 and revision of failed ankle fusion in 1. An augmented tibia was used in 13, an augmented talus in 13, and both augmented tibia and talus in 9 cases. There were no early surgical complications. One patient required debridement and implant retention for late deep infection. No implants have been revised. The average MOXFQ score improved by 19.3 points at most recent follow-up. The average AOS score improved by 25.2 points.

CONCLUSION

The early results of a modular augmented ankle arthroplasty system have shown satisfactory patient outcomes with a low complication and re-operation rate and present another option for patients with larger bone defects. This is a small series, and a larger series with long-term follow-up would be beneficial.

LEVELS OF EVIDENCE

Level IV: Case series.

Total Ankle Arthroplasty in Young Patients

With continuing advancements in total ankle arthroplasty (TAA), it is quickly becoming the procedure of choice for older patients with end-stage ankle arthritis. Multiple studies have been conducted on younger patients who have undergone TAA with promising results, but is it the procedure of choice? Considerations of TAA versus ankle arthrodesis, TAA implant longevity, outcomes of revision TAA, and whether patients should be offered an arthrodesis with plans for conversion to arthroplasty may help elucidate whether pursuing ankle arthroplasty in a younger, more active population is the correct approach for surgeons.

Outcomes of Revision Total Ankle Replacement

The objective of this study is to provide an up-to-date review of the outcomes of revision total ankle arthroplasty (TAA). Relevant studies published over the last decade were reviewed. Twelve studies were included. At a median follow-up of 4 years, the median survival and reoperation rates were 86% and 16%, respectively. Significant postoperative improvements in patient-reported outcome measures were recorded in 6 studies. Significant improvement in alignment was documented in 1 study only. Revision TAA is a safe procedure that can produce good outcomes. Nevertheless, data relating to long-term outcome are still limited in quantity and duration.

Survival and risk assessment in revision arthroplasty of the ankle

Aims

Implant failure has become more common as the number of primary total ankle arthroplasties (TAAs) performed has increased. Although revision arthroplasty has gained attention for functional preservation, the long-term results remain unclear. This study aimed to assess the long-term outcomes of revision TAA using a mobile-bearing prosthesis in a considerably large cohort; the risk factors for failure were also determined.

Methods

This single-centre retrospective cohort study included 116 patients (117 ankles) who underwent revision TAA for failed primary TAA between July 2000 and March 2010. Survival analysis and risk factor assessment were performed, and clinical performance and patient satisfaction were evaluated preoperatively and at last follow-up.

Results

The mean duration from initial revision TAA to last follow-up was 15.0 years (SD 3.0; 11.2 to 20.5). The cumulative survival rates of the revised ankles were 81% (95% confidence interval (CI) 74% to 88%), 74% (65% to 82%), and 70% (61% to 79%) at five, ten, and 15 years, respectively. Comorbidities prior to primary TAA, aseptic loosening, instability, or grafting of cysts were found to be the most common risk factors for secondary revision. The median value for preoperative pain, as assessed using the visual analogue scale, declined from 6 (interquartile range (IQR) 5 to 8) to 2 (IQR 0 to 5) (p < 0.001) and the mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score improved from 43 (SD 17) preoperatively to 70 (SD 20) (p < 0.001) at last follow-up.

Conclusion

Revision TAA offers acceptable survival rates after 15 years; it therefore offers a valuable option for treatment of implant failure in carefully selected cases. Although patient-reported outcomes improve substantially, the degree of improvement reported following primary TAA is not achieved.

Survival of revision ankle arthroplasty

Aims

The number of revision total ankle arthroplasties (TAAs) which are undertaken is increasing. Few studies have reported the survival after this procedure. The primary aim of this study was to analyze the survival of revision ankle arthroplasties using large datasets. Secondary aims were to summarize the demographics of the patients, the indications for revision TAA, further operations, and predictors of survival.

Methods

The study combined data from the National Joint Registry and NHS Digital to report the survival of revision TAA. We have previously reported the failure rates and risk factors for failure after TAA, and the outcome of fusion after a failed TAA, using the same methodology. Survival was assessed using life tables and Kaplan Meier graphs. Cox proportional hazards regression models were fitted to compare failure rates.

Results

A total of 228 patients underwent revision TAA. The mean follow-up was 2.6 years (SD 2.0). The mean time between the initial procedure and revision was 2.3 years (SD 1.8). The most commonly used implant was the Inbone which was used in 81 patients. A total of 29 (12.7%) failed; nine (3.9%) patients underwent a further revision, 19 (8.3%) underwent a fusion, and one (0.4%) had an amputation. The rate of survival was 95.4% (95% confidence interval (CI) 91.6 to 97.5) at one year, 87.7% (95% CI 81.9 to 91.7; n = 124) at three years and 77.5% (95% CI 66.9 to 85.0; n = 57) at five years. Revision-specific implants had a better survival than when primary implants were used at revision. A total of 50 patients (21.9%) had further surgery; 19 (8.3%) underwent reoperation in the first 12 months. Cox regression models were prepared. In crude analysis the only significant risk factors for failure were the use of cement (hazard ratio (HR) 3.02 (95% CI 1.13 to 8.09)) and the time since the primary procedure (HR 0.67 (95% CI 0.47 to 0.97)). No risk factors for failure were identified in multivariable Cox regression modelling.

Conclusion

Revision TAAs have good medium term survival and low rates of further surgery. New modular revision implants appear to have improved the survival compared with the use of traditional primary implants at revision.

Use of Femoral Head Allograft for Extended Bone Loss in Revision Total Ankle Arthroplasty: A Case Report

CASE

A 38-year-old male patient presented with severe ankle pain 13 years after a total ankle arthroplasty (TAA). Radiographic evaluation revealed loosening of the implant and extensive osteolytic lesions. The medial tibial plafond and malleolus were reconstructed using a fresh-frozen femoral head graft, and revision TAA was performed. The midterm results were satisfactory, with adequate integration of the allograft and stable implant components.

CONCLUSION

The use of the allograft technique in revision TAA is feasible in the presence of severe bone loss, including the malleoli, and allows firm component fixation of the reconstructed bone.

Republication of "Total Ankle Replacement Conversion to Tibiotalocalcaneal Arthrodesis With Bulk Femoral Head Allograft and Pseudoelastic Intramedullary Nail Providing Sustained Joint Compression"

Tibiotalocalcaneal (TTC) arthrodesis is commonly performed to salvage a failed total ankle replacement. These salvage procedures are complicated by significant bone loss from the ankle replacement and are associated with low patient satisfaction. Here, we describe 2 cases of patients who presented with a failed total ankle replacement and underwent arthrodesis using a bulk femoral head allograft and a novel pseudoelastic intramedullary nail. The intramedullary nail contains an internal pseudoelastic element that adapts to bone resorption and settling allowing for compression to be maintained at the arthrodesis sites throughout healing. In the first case, a 65-year-old woman with a failed total ankle replacement underwent TTC arthrodesis. The second case involved an obese 53-year-old woman who had previously undergone 2 total ankle replacement procedures that resulted in unsuccessful outcomes. In both cases, union was demonstrated on computed tomographic scan by 6 months. At 2 years postsurgery, both patients were satisfied with the procedure. These cases provide preliminary evidence that tibiotalocalcaneal arthrodesis with a pseudoelastic IM nail and structural allograft is an appropriate treatment for failed total ankle replacements. Level of Evidence: Level IV, therapeutic, case series.

How Does a Novel In Situ Fixed-bearing Implant Design Perform in Revision Ankle Arthroplasty in the Short Term? A Survival, Clinical, and Radiologic Analysis

BACKGROUND

Given the growing number of primary total ankle replacements (TAR), an increase in the number of patients undergoing subsequent revisions might be expected. Achieving a stable and balanced ankle while preserving the remaining bone stock as much as possible is crucial for success in revision TAR. Most reported techniques rely on bulky implants with extended fixation features. Since 2018, we have used a novel, three-component ankle prosthesis for revision that is converted in situ to a fixed-bearing, two-component ankle prosthesis once the components have found their position according to an individual's anatomy. The results of this novel concept (fixation, revision, pain, or function) have not, to our knowledge, been reported.

QUESTIONS/PURPOSES

What are the short-term results with this new revision TAR design, in terms of (1) repeat revision surgery, (2) patient-reported outcomes on the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, (3) pain according to the VAS, and (4) radiographic signs of fixation?

METHODS

Between February 2018 and February 2020, we performed 230 TAR surgeries (in 206 patients) for any indication in our clinic. The novel semiconstrained, uncemented Hintermann Series H2 © implant was used in 96% (220 of 230) of procedures (201 patients). Fifty-four percent (119 of 220) of these were converted from an existing TAR to H2, which was the focus of the present study. However, only 45% (54 of 119) of these conversions to H2 were eligible for analysis. These patients had a mean age of 63 ± 12 years, and 43% (23 of 54) were women. The median (range) follow-up time was 3.2 years (2.0 to 4.3). The H2 design allows in situ conversion to a fixed-bearing system, with minimal bone resection. It achieves translational and rotational stability while preserving function and supporting the periarticular soft tissues. We defined repeat revision as exchange of one or both metal components, ankle fusion, or amputation and assessed it using a cumulative incidence survivorship estimator. Factors potentially associated with revision were assessed using Cox regression analyses. Clinical and radiologic outcomes were assessed preoperatively and at the most recent follow-up interval. Clinical outcomes included pain on the VAS (average pain during normal daily activity during the past seven days) and AOFAS score. Radiologic outcomes were the tibial articular surface angle, tibiotalar surface angle, talar tilt angle in the coronal plane, and AP offset ratio in the sagittal plane, as well as radiolucent lines and radiographic signs of loosening, defined as change in position greater than 2° of the flat base of the tibia component in relation to the long axis of the tibia, subsidence of the talar component into the talus greater than 5 mm, or change in position greater than 5° relative to a line drawn from the top of the talonavicular joint to the tuberosity of the calcaneus, as seen on plain weightbearing radiographs.

RESULTS

The cumulative incidence of repeat revision after 1 and 2 years was 5.6% (95% CI 0% to 11%) and 7.4% (95% CI 0% to 14%), respectively. With the numbers available, no clinical factors we analyzed were associated with the risk of repeat revision. The median values of all assessed clinical outcomes improved; however, not all patients improved by clinically important margins. The median (range) AOFAS ankle-hindfoot score increased (from 50 [16 to 94] to 78 [19 to 100], difference of medians 28; p < 0.01), and the median pain on the VAS decreased (from 5 [0 to 9] to 2 [0 to 9], difference of medians 3; p < 0.01) from before surgery to follow-up at a minimum of 2 years. Radiographically, lucency was seen in 12% (6 of 49 patients) and loosening was seen in 8% (4 of 49). One of these patients showed symptomatic loosening and was among the four patients overall who underwent revision. We could not assess risk factors for repeat revision because of the low number of events (four).

CONCLUSION

The investigated new in situ fixed-bearing ankle design achieved overall better short-term results than those reported in previous research. Destabilization of the ankle joint complex, soft tissue insufficiency, and possible changes of the joint configuration need an optimal solution in revision arthroplasty. The studied implant might be the answer to this complex issue and help surgeons in the perioperative decision-making process. However, a relatively high percentage of patients did not achieve a clinically important difference. Observational studies are needed to understand long-term implant behavior and possibly to identify ankles benefiting the most from revision.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Mid-term functional outcomes following reoperation after total ankle arthroplasty: A retrospective cohort study

BACKGROUND

Despite a significant reported rate of non-revision reoperation after total ankle arthroplasty (TAA), it is uncertain if these subsequent procedures have an impact on the longer term outcomes. This study aimed to compare minimum five-year functional outcomes of patients who had undergone reoperation after TAA to those who did not require reoperation.

METHODS

Seventy-six ankles (74 patients) who underwent TAA with the Salto Talaris fixed bearing system between 2007 and 2014 were allocated into two groups based on presence (n = 16) or absence of reoperation (n = 60). Reoperations included all secondary procedures after index TAA, excluding revision surgeries requiring removal or exchange of the original prosthesis. The foot and ankle outcome score (FAOS) at preoperative and minimum five-year follow-up was compared between the groups. Additionally, improvements in FAOS subscales were compared. Preoperative deformity, postoperative implant alignment, number of periprosthetic cysts, and subsidence between groups were compared using standard weightbearing radiographs.

RESULTS

The most common cause of reoperation was gutter impingement (n = 11), followed by stress fracture of the medial malleolus (n = 2), tarsal tunnel syndrome (n = 1), periprosthetic cyst (n = 1), and infection (n = 1). In comparison to the non-reoperation group, all FAOS subscales except for the Sports and Recreational Activities subscale were significantly lower in the reoperation group at final follow-up. The reoperation group exhibited significantly less improvement in the Pain, Symptoms, and Quality of Life subscales at final follow-up (p < 0.05). There were no statistical differences in the radiographic parameters between both groups.

CONCLUSIONS

Patients who underwent reoperation after TAA demonstrated inferior functional outcomes at mid-term follow-up. An emphasis should be placed on preventing possible causes of reoperations to achieve favorable patient outcomes. Additionally, if a reoperation is deemed necessary, a thorough evaluation and surgical correction of underlying causes should be achieved.

The outcomes of revision surgery for a failed ankle arthroplasty

Aims

Revision rates for ankle arthroplasties are higher than hip or knee arthroplasties. When a total ankle arthroplasty (TAA) fails, it can either undergo revision to another ankle replacement, revision of the TAA to ankle arthrodesis (fusion), or amputation. Currently there is a paucity of literature on the outcomes of these revisions. The aim of this meta-analysis is to assess the outcomes of revision TAA with respect to surgery type, functional outcomes, and reoperations.

Methods

A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Medline, Embase, Cinahl, and Cochrane reviews were searched for relevant papers. Papers analyzing surgical treatment for failed ankle arthroplasties were included. All papers were reviewed by two authors. Overall, 34 papers met the inclusion criteria. A meta-analysis of proportions was performed.

Results

Six papers analyzed all-cause reoperations of revision ankle arthroplasties, and 14 papers analyzed failures of conversion of a TAA to fusion. It was found that 26.9% (95% confidence interval (CI) 15.4% to 40.1%) of revision ankle arthroplasties required further surgical intervention and 13.0% (95% CI 4.9% to 23.4%) of conversion to fusions; 14.4% (95% CI 8.4% to 21.4%) of revision ankle arthroplasties failed and 8% (95% CI 4% to 13%) of conversion to fusions failed.

Conclusion

Revision of primary TAA can be an effective procedure with improved functional outcomes, but has considerable risks of failure and reoperation, especially in those with periprosthetic joint infection. In those who undergo conversion of TAA to fusion, there are high rates of nonunion. Further comparative studies are required to compare both operative techniques. Cite this article: Bone Jt Open 2022;3(7):596–606.

Midterm Survivorship of the INBONE II Total Ankle Arthroplasty

BACKGROUND

The use of total ankle arthroplasty (TAA) in the treatment of ankle arthritis has grown substantially as advancements are made in design and surgical technique. Among the criteria guiding the choice between arthroplasty and arthrodesis, the long-term survival and postoperative outcomes are of crucial importance. Although outcomes of the INBONE I have been published, there is limited midterm survival data for the INBONE II. The purpose of this study was to determine the radiographic and patient-reported outcomes, and survivorship of this prosthesis in patients with a minimum 5-year follow-up.

METHODS

We retrospectively identified 51 ankles (46 patients) from 2010 to 2015 who underwent TAA with the INBONE II prosthesis at our institution. Of these, 44 cases had minimum clinical follow-up of 5 years (mean, 6.4; range 5-9). Median age was 66 years (range 42-81) and median BMI was 27.5 (range 20.1-33.0). A chart review was performed to record the incidence of revision and reoperation. Preoperative and postoperative radiographs were analyzed to assess the coronal tibiotalar alignment (TTA), the talar inclination angle, and the presence of periprosthetic lucencies and cyst formation. Preoperative and minimum 5-year postoperative Foot and Ankle Outcome Score (FAOS) subscales were compared. Survivorship was determined by incidence of revision, defined as removal of a metallic component.

RESULTS

The survivorship at 5 years was 98% and the rate of reoperation was 7.8% (n = 4); 2 patients underwent irrigation and debridement for infection, 1 patient underwent a medializing calcaneal osteotomy, and 1 patient underwent open gutter debridement, 1 patient underwent a revision of a subsided talar component at 3.2 years after index surgery. Average postoperative TTA was 88.6 degrees, with 42 rated as neutral (85-95 degrees), 2 varus (<85 degrees), and no valgus (>95 degrees) ankles. At final follow-up, asymptomatic periprosthetic cysts were observed in 8 patients. All FAOS domain scores improved between preoperative and final follow-up.

CONCLUSION

At midterm follow-up, we observed significant improvement in radiographic alignment and patient-reported outcome scores for the INBONE II total ankle prosthesis. In addition, this cohort has had a relatively low reoperation rate and high survivorship.

LEVEL OF EVIDENCE

Level IV, case series.

A Prospective Cohort Study Comparing Functional Outcomes of Primary and Revision Ankle Replacements

BACKGROUND

The number of ankle and revision ankle replacements performed is increasing. There is limited research into functional outcomes, especially in revision ankle replacements. The primary aim of this cohort study was to determine the functional improvements following primary and revision ankle replacements and compare which gave the greatest improvement in functional scores.

METHODS

A single-center prospective cohort study was undertaken between 2015 and 2018. All patients were followed up for a minimum of 2 years. Patients undertook a preoperative and 2-year Manchester Oxford Foot Questionnaire (MoxFQ) score. The Mann Whitney test was undertaken.

RESULTS

A total of 33 primary and 23 revision ankle replacements were performed between 2015 and 2018. The mean age was 69.3 years for primary replacements and 64.7 years for revision replacements. All primary replacements were the Infinity ankle replacement. Revision replacements were either the Inbone II or Invision. The indication for revision was 9 aseptic loosening, 6 infections, 5 cysts, and 3 malposition. Seventeen were performed as a single stage and 6 as a 2-stage revision. The overall MoxFQ improved by a mean of 48.8 for primaries and 20.2 for revisions (P = .024). The walking/standing domain improved by 57.5 for primaries and 22.5 for revisions (P = .016), the pain score improved by 43.0 and 32.3 (P = .009), and the social interaction improved by 40.0 and 11.7 (P = .128).

CONCLUSION

Both primary and revision ankle replacements result in improved functional scores. In this relatively small cohort with the implants used, primary ankle replacements though have a significantly greater improvement in functional scores compared to revision ankle replacements.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Evaluating and Managing the Painful Total Ankle Replacement

The number of total ankle replacements (TARs) performed in the United States has dramatically increased in the past 2 decades due to improvements in implant design and surgical technique. Yet as the prevalence of TAR increases, so does the likelihood of encountering complications and the need for further surgery. Patients with new-onset or persistent pain after TAR should be approached systematically to identify the cause: infection, fracture, loosening/subsidence, cysts/osteolysis, impingement, and nerve injury. The alignment of the foot and ankle must also be reassessed, as malalignment or adjacent joint pathology can contribute to pain and failure of the implant. Novel advanced imaging techniques, including single-photon emission computed tomography and metal-subtraction magnetic resonance imaging, are useful and accurate in identifying pathology. After the foot and ankle have been evaluated, surgeons can also consider contributing factors such as pathology outside the foot/ankle (eg, in the knee or the spine). Treatment of the painful TAR is dependent on etiology and may include debridement, bone grafting, open reduction and internal fixation, realignment of the foot, revision of the implants, arthrodesis, nerve repair/reconstruction/transplantation surgery, or, in rare cases, below-knee amputation.Level of Evidence: Level V, expert opinion or review.

Two-Staged Revision Total Ankle Arthroplasty Surgery with Primary Total Ankle Arthroplasty System: A Case Report

CASE

Case of a 2-staged revision surgical technique for the treatment of an aseptic total ankle arthroplasty (TAA) loosening: first surgery: removal of the loosened and painful TAA Scandinavian Total Ankle Replacement, with exclusion of infection, and reconstruction of the large bone defect (bone-defect downsizing surgery); proof of successful ankle bone reconstruction by CT-scan imaging; second surgery: implantation of a primary VANTAGE TAA (ankle reconstruction with new primary TAA).

CONCLUSION

The present case shows the management of a failed TAA with bone defect by performing a 2-step surgical approach: removal of loosened TAA with simultaneous bone stock restoration and then implantation of a new primary TAA. This concept is a possible alternative to a post-TAA ankle arthrodesis or to the use of a TAA revision system.

Pathogenesis, Evaluation, and Management of Osteolysis Following Total Ankle Arthroplasty

Periprosthetic osteolysis is a common occurrence after total ankle arthroplasty (TAA) and poses many challenges for the foot and ankle surgeon. Osteolysis may be asymptomatic and remain benign, or it may lead to component instability and require revision or arthrodesis. In this article, we present a current and comprehensive review of osteolysis in TAA with illustrative cases. We examine the basic science principles behind the etiology of osteolysis, discuss the workup of a patient with suspected osteolysis, and present a review of the evidence of various management strategies, including grafting of cysts, revision TAA, and arthrodesis.Level of Evidence: Level V, expert opinion.

Radiographic and Clinical Outcomes of the Salto Talaris Total Ankle Arthroplasty

BACKGROUND

The Salto Talaris is a fixed-bearing implant first approved in the US in 2006. While early surgical outcomes have been promising, mid- to long-term survivorship data are limited. The aim of this study was to present the survivorship and causes of failure of the Salto Talaris implant, with functional and radiographic outcomes.

METHODS

Eighty-seven prospectively followed patients who underwent total ankle arthroplasty with the Salto Talaris between 2007 and 2015 at our institution were retrospectively identified. Of these, 82 patients (85 ankles) had a minimum follow-up of 5 (mean, 7.1; range, 5-12) years. The mean age was 63.5 (range, 42-82) years and the mean body mass index was 28.1 (range, 17.9-41.2) kg/m². Survivorship was determined by incidence of revision, defined as removal/exchange of a metal component. Preoperative, immediate, and minimum 5-year postoperative AP and lateral weightbearing radiographs were reviewed; tibiotalar alignment (TTA) and the medial distal tibial angle (MDTA) were measured to assess coronal talar and tibial alignment, respectively. The sagittal tibial angle (STA) was measured; the talar inclination angle (TIA) was measured to evaluate for radiographic subsidence of the implant, defined as a change in TIA of 5 degrees or more from the immediately to the latest postoperative lateral radiograph. The locations of periprosthetic cysts were documented. Preoperative and minimum 5-year postoperative Foot and Ankle Outcome Score (FAOS) subscales were compared.

RESULTS

Survivorship was 97.6% with 2 revisions. One patient underwent tibial and talar component revision for varus malalignment of the ankle; another underwent talar component revision for aseptic loosening and subsidence. The rate of other reoperations was 21.2% (n = 18), with the main reoperation being exostectomy with debridement for ankle impingement (n = 12). At final follow-up, the average TTA improved 4.4 (± 3.8) degrees, the average MDTA improved 3.4 (± 2.6) degrees, and the average STA improved 5.3 (± 4.5) degrees. Periprosthetic cysts were observed in 18 patients, and there was no radiographic subsidence. All FAOS subscales demonstrated significant improvement at final follow-up.

CONCLUSIONS

We found the Salto Talaris implant to be durable, consistent with previous studies of shorter follow-up lengths. We observed significant improvement in radiographic alignment as well as patient-reported clinical outcomes at a minimum 5-year follow-up.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Clinical and Radiographic Outcomes of Revision Total Ankle Arthroplasty Using an Intramedullary-Referencing Implant

BACKGROUND

Treatment of failed total ankle arthroplasty (TAA) is challenging. Limited literature is available on options and outcomes of revision arthroplasty despite failure rates ranging from 10% to 23% within 10 years after primary TAA. This study reports the clinical and radiographic outcomes of revision TAA using a fixed-bearing, intramedullary-referencing implant.

METHODS

A retrospective review was performed of 18 consecutive revision TAA cases between 2008-2015 using an intramedullary-referencing, fixed-bearing, 2-component total ankle system. Demographic and radiographic data were collected preoperatively, immediately postoperatively, and at the most recent follow-up. Functional outcome data were collected immediately postoperatively and at mean follow-up 47.5 months.

RESULTS

Eighteen patients underwent revision TAA, with 77.8% (14/18) implant survival. Index revision was performed most commonly for aseptic talar subsidence (55.6%) or implant loosening (tibia, 29.4%; talus, 58.9%). Following revision, 22.2% (4/18) patients required reoperation at a mean 57.3 (39-86) months. Osteolysis of the tibia, talus, and fibula was present preoperatively in 66.7% (12/18), 38.9% (7/18), and 38.9% (7/18) of patients, respectively, with progression of osteolysis in 27.8% (5/18), 11.1% (2/18) and 11.1% (2/18) of patients, respectively. Subsidence of the tibial and talar revision components was observed in 38.9% (7/18) and 55.6% (10/18) of patients, respectively. The median American Orthopaedic Foot & Ankle Society (AOFAS) score was 74.5 (26-100) and Foot Function Index (FFI) score 10.2 (0-50.4).

CONCLUSION

Early results of intramedullary-referencing revision TAA demonstrated good patient-reported outcomes with maintenance of radiographic parameters at mean follow-up of 47.5 months. Aseptic talar subsidence or loosening were the main postoperative causes of reoperation. Revision arthroplasty utilizing an intramedullary-referencing implant was a viable option for the failed TAA.

LEVEL OF EVIDENCE

Level IV, case series.

Intra-articular Injections of Hyaluronic Acid on Osteochondral Lesions of the Talus After Failed Arthroscopic Bone Marrow Stimulation

BACKGROUND

The purpose of the study was to compare clinical and functional outcomes before and after hyaluronic acid (HA) injections in patients with osteochondral lesions of the talus who experienced a failure of their primary treatment with arthroscopic microfracture surgery.

METHODS

A total of 40 patients were included in the final study. These patients had received microfracture surgery but continued to experience postoperative pain over an average of 13.0 months (range, 0-81 months) and were available for investigation with a mean follow-up for 29.1 months (SD 14.7; range 2.6-79.6 months). All patients received intra-articular injections of HA once per week for 3 weeks. We assessed clinical and functional outcomes before and after injection using the American Orthopaedic Foot & Ankle Society (AOFAS) score, Foot and Ankle Outcome Score (FAOS), Short Form Health Survey (SF-36), the visual analog scale (VAS) for pain, and the Alexander subjective scale.

RESULTS

The AOFAS score significantly increased from 50.7 ± 13.8 to 79.9 ± 13.8 and the FAOS scores for symptom, pain, daily living, and sports were significantly higher postinjection compared to preinjection (all P < .001). Similarly, the mean VAS for pain was significantly decreased after 6 weeks following injection and continued to decrease over the follow-up period; the mean VAS was significantly lower postinjection compared to preinjection at 12 months (P < .001).

CONCLUSION

Intra-articular HA injections on average significantly improved clinical and functional scores after failed primary operative treatment. HA injections may provide an alternative to secondary operative treatment and provide better clinical outcomes than other conservative treatments.

LEVEL OF EVIDENCE

Level II, prospective observational cohort study.

Salvage Arthrodesis for Failed Total Ankle Replacement

Salvage arthrodesis for failed total ankle replacement can be a successful procedure. The decision to perform salvage arthrodesis is based on many factors, but the following are the most important indications: severe loss of bonestock (tibia, talus, or both), inadequate soft tissue coverage, or the inability to eradicate an infection. With few revision implants on the market, salvage arthrodesis is currently the most common treatment for failed replacement and justification for revision ankle replacement is limited when any of these factors are present.

Nuclear Medicine for the Orthopedic Foot and Ankle Surgeon

Nuclear medicine has been widely applied as a diagnostic tool for orthopedic foot and ankle pathology. Although its indications have diminished with improvements in and the availability of magnetic resonance imaging, nuclear medicine still has a significant and valuable role. The present article offers a comprehensive and current review of the most common nuclear imaging modalities for the orthopedic foot and ankle surgeon. Methods discussed include bone scintigraphy, gallium citrate scintigraphy, labeled-leukocyte scintigraphy, and single-photon emission computed tomography (SPECT). We review the indications and utility of these techniques as they pertain to specific foot and ankle conditions, including osteomyelitis, stress fractures, talar osteochondral lesions, complex regional pain syndrome, oncology, plantar fasciitis, and the painful total ankle arthroplasty. We conclude with a discussion of our approach to nuclear medicine with illustrative cases. Level of Evidence: Level V, expert opinion.

Impact of Sagittal Talar Inclination on Total Ankle Replacement Failure

BACKGROUND

Restoration of ankle alignment is important in total ankle arthroplasty (TAA), but sagittal alignment of the talar component is less studied than coronal sagittal. Little has been published on the importance of sagittal talar alignment in TAA. The radiographic talar component inclination was hypothesized to be predictive of TAA survival, subsidence, and functional outcomes.

METHODS

A retrospective review of the Vancouver End-Stage Ankle Arthritis Database was performed on all TAAs at a single center over 11 years utilizing 1 of 2 implants. Talar component inclination (TCI) angles were measured and standard descriptive statistics were completed with a survival analysis. Inter- and intraobserver reliability were determined. Postoperative TCI angles were analyzed against several definitions of TAA survival and patient-reported outcome measures from the database. A total of 109 TAAs satisfied inclusion and exclusion criteria.

RESULTS

A postoperative talar component inclination angle greater than 22 degrees was associated with talar component anterior subsidence, defined as a change in that angle of 5 degrees or more between postoperative and last available radiographs. This was still significant after adjusting for confounders: age, gender, body mass index, and presence of inflammatory arthritis. All measured angles had good inter- and intraobserver reliability.

CONCLUSION

Surgeons should avoid dorsiflexing the talar prosthesis during TAA, which hypothetically diminishes the ankle critical dorsiflexion range. This may cause anterior talar undercoverage in terminal dorsiflexion and may edge load the talar prosthesis, predisposing to anterior subsidence. Elevated TCI was a simple and reliable radiographic measurement to predict long-term TAA outcome due to predictable anterior subsidence of the talar prosthesis.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Revision Surgery for Metal Component Failure in Total Ankle Arthroplasty

Background:

Metal component failure in total ankle arthroplasty (TAA) is difficult to treat. Traditionally, conversion to an arthrodesis has been advocated. Revision TAA surgery has become more common with availability of revision implants and refinement of bone-conserving primary implants. The goal of this study was to analyze the clinical results and patient-reported outcomes for patients undergoing revision total ankle arthroplasty.

Methods:

We retrospectively reviewed prospectively collected data on 52 patients with a mean age of 63.5 ± 9.6 years who had developed loosening or collapse of major metal components following primary TAA. These patients were compared to a case-matched control group of 52 primary TAAs performed at the host institution with a minimum of 2 years’ follow-up. Cases of isolated polyethylene exchange, infection, or extra-articular realignment procedures were excluded. The American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, Short Form 36 (SF-36), Short Musculoskeletal Function Assessment (SMFA), and pain scores were prospectively collected. Clinical data was collected through review of the electronic medical record to identify reasons for clinical failure, where clinical failure was defined as second revision or conversion to arthrodesis or amputation.

Results:

The identified causes of failure of primary TAA were aseptic loosening of both components (42%), talar component subsidence/loosening (36%), coronal talar subluxation (12%), tibial loosening (8%), and talar malrotation (2%). Thirty-one patients (59.5%) underwent revision of all components, 20 (38.5%) just the talar and polyethylene components, and one (2%) the tibial and polyethylene components. The average time to revision was 5.5 years ± 5.4 with a follow-up of 3.1 years ± 1.5 after revision. Eleven (21.2%) revision arthroplasties required further surgery: 6 required conversion to arthrodesis and 5 required second revision TAA. Pain scores, SF-36 scores, SMFA scores, and AOFAS Hindfoot scores all improved after revision surgery but never reached the same degree of improvement seen after primary TAA.

Conclusions:

Clinical and patient-reported outcomes of revision ankle arthroplasty after metal component failure significantly improved after surgery, although the recovery time was longer. In this series, 21.2% of revision TAAs required a second revision TAA or arthrodesis surgery. Various prostheses performed similarly when used for revision surgery. Revision TAA can offer significant improvements postoperatively.

Level of Evidence:

Level III, therapeutic.

Infections in primary total ankle replacement: Anterior approach versus lateral transfibular approach

BACKGROUND

Total ankle replacement (TAR) represents an alternative to fusion for the treatment of end-stage ankle osteoarthritis. The aim of the present study was to retrospectively assess the frequency of infections between TARs with anterior and lateral transfibular approach at 12-months follow-up.

METHODS

81 TARs through an anterior approach and 69 TARs through a lateral approach were performed between May 2011 and July 2015. We compared surgical time and tourniquet time, as well as superficial and deep infections frequency during the first 12 postoperative months.

RESULTS

In the anterior approach group, there were 3 (3.7%) deep infections and 4 (4.9%) superficial wound infections. In the lateral approach group, there were 1 (1.4%) deep infection and 2 superficial wound infections (2.9%). There were not statistically significant differences between the groups. There was a significant difference between anterior approach (115minutes) and lateral approach group (179minutes) in terms of surgical time (P<0.001).

CONCLUSIONS

The frequency of superficial and deep periprosthetic infections during the first postoperative year was not significantly different in the lateral approach group compared to the anterior approach group, despite the significantly longer surgical time in the lateral transfibular approach group.

Patient-Reported Outcomes Before and After Primary and Revision Total Ankle Arthroplasty

BACKGROUND:

Studies examining the clinical outcomes of revision total ankle arthroplasty (TAA) are sparse. Revision TAA surgery has become more common with availability of revision implants and refinement of bone-conserving primary implants. In this study, patient-reported results and clinical outcomes were analyzed for a cohort of patients who underwent both primary and revision TAA at a single high-volume institution.

METHODS:

We retrospectively reviewed prospectively collected data on 29 patients with failed primary total ankle arthroplasty. Cases of isolated polyethylene exchange, infection, or extra-articular realignment procedures were excluded. Patient-reported outcome (PRO) measures and clinical results were reviewed in this longitudinal study.

RESULTS:

Fifteen patients (51.7%) underwent revision of just the talar and polyethylene components while 13 patients (44.8%) underwent revision of all components. The most common cause was talar subsidence (51.7%). The average time to revision was 3.9 years with a follow-up of 3.2 years after revision, and 3 (10.3%) revision arthroplasties required further surgery; 2 required conversion to arthrodesis and 1 required second revision TAA. Improvements in PROs were better after primary than revision TAA.

CONCLUSIONS:

Clinical and patient-reported results of revision ankle arthroplasty after metal component failure improved significantly but never reached the improvements seen after primary ankle arthroplasty. In our series, 10.3% of revision TAAs required a second revision TAA or arthrodesis surgery.

LEVELS OF EVIDENCE:

Therapeutic Level III, comparative series.

Total Ankle Replacement Conversion to Tibiotalocalcaneal Arthrodesis With Bulk Femoral Head Allograft and Pseudoelastic Intramedullary Nail Providing Sustained Joint Compression

Tibiotalocalcaneal (TTC) arthrodesis is commonly performed to salvage a failed total ankle replacement. These salvage procedures are complicated by significant bone loss from the ankle replacement and are associated with low patient satisfaction. Here, we describe 2 cases of patients who presented with a failed total ankle replacement and underwent arthrodesis using a bulk femoral head allograft and a novel pseudoelastic intramedullary nail. The intramedullary nail contains an internal pseudoelastic element that adapts to bone resorption and settling allowing for compression to be maintained at the arthrodesis sites throughout healing. In the first case, a 65-year-old woman with a failed total ankle replacement underwent TTC arthrodesis. The second case involved an obese 53-year-old woman who had previously undergone 2 total ankle replacement procedures that resulted in unsuccessful outcomes. In both cases, union was demonstrated on computed tomographic scan by 6 months. At 2 years postsurgery, both patients were satisfied with the procedure. These cases provide preliminary evidence that tibiotalocalcaneal arthrodesis with a pseudoelastic IM nail and structural allograft is an appropriate treatment for failed total ankle replacements.

Level of Evidence:

Level IV, therapeutic, case series.

Design Rationale for Total Ankle Arthroplasty Systems: An Update

The design of total ankle arthroplasty systems is evolving as a result of findings from longer-term studies. Our understanding of modes of failure has increased, and surgical techniques have become more refined. Currently, five total ankle arthroplasty systems are used in the United States. The landscape has changed considerably in the decade since the latest article reviewing total ankle design was published. Some implants with acceptable intermediate results had much poorer outcomes at 7- to 10-year follow-up. As more research showing mid- to long-term outcomes is published, the design rationale and current outcomes data for each of these implants must be considered.

Finite Element Study of Implant Subsidence and Medial Tilt in Agility Ankle Replacement

Background

Clinical studies indicate that in total ankle arthroplasty, postoperative implant subsidence and medial tilt become two significant concerns of the ankle replacement system, and which are associated with the contact between the bones and the talar component. Up to now, little attention has focused on the contact between the bones and the talar component.

Material/Methods

In order to address implant subsidence and medial tilt, one three-dimensional finite element model of contact between the bone and the talar components was built with the material properties of the cancellous bone interpolated from the experimental data, which represents variation of material properties through the cancellous bones. The finite element model was used to study the following: variation of the Young’s modulus of the bones, stiffness of the talar component, loading direction, and loading magnitude with the implant subsidence.

Results

The computational results reveal that a variety of Young’s modulus of the cancellous bones causes the medial tilting of the talar component and that big plastic strains are associated with tilting. The implant subsidence increases from 0.169 mm to 0.269 mm when the loading changes from 272 kg to 408 kg. However, to the contrary, the implant subsidence decreases from 0.2676 mm to 0.1783 mm when Young’s modulus of the bones increases 50%. However, the implant subsidence shows little change with a different Young’s modulus of the talar component from 88 GPa to 132 GPa.

Conclusions

Our study indicates that a variety of different Young’s modulus of the cancellous bones cause the medial tilting of the talar component. To solve subsidence and tilting, both the contact area and the variation of material properties should be taken into account.

Adjacent Joint Kinematics After Ankle Arthrodesis During Cadaveric Gait Simulation

BACKGROUND

Arthrodesis is an effective and reliable treatment for end-stage ankle arthritis; however, many patients develop ipsilateral adjacent joint arthritis following surgery. The mechanism that drives adjacent joint arthritis remains uncertain. Cadaveric simulation permits direct investigation of the effects of both arthrodesis and movement strategy on adjacent joints during simulated walking. The objective of this study was to identify the isolated effect of ankle arthrodesis on adjacent joint kinematics during simulated walking.

METHODS

Effects of ankle arthrodesis on adjacent joint kinematics were assessed in 8 cadaveric foot and ankle specimens using a robotic gait simulator. Gait parameters acquired from healthy adults and patients with ankle arthrodesis were used as inputs for simulations. Three-dimensional subtalar and talonavicular joint kinematics were directly measured before and after ankle arthrodesis, and healthy- and arthrodesis-gait parameters were applied to identify the isolated effect of the ankle arthrodesis on adjacent joint kinematics.

RESULTS

Ankle arthrodesis increased subtalar and talonavicular joint motion during early and midstance independent of which gait parameters were used as inputs to the gait simulator. However, adjacent joint motions did not differ between the control and arthrodesis condition during late stance, when the healthy gait parameters were used as inputs. Conversely, adjacent joint motion decreased during late stance following arthrodesis when simulating gait using parameters typical in arthrodesis patients.

CONCLUSIONS

Regardless of the gait parameter inputs, subtalar and talonavicular joint motions increased from normal kinematics, which likely increase the biomechanical burden placed on these adjacent joints and may lead to joint degeneration.

CLINICAL RELEVANCE

Increased motion of the adjacent joints caused by ankle arthrodesis may explain the articular degeneration observed clinically.

Ankle Arthrodiastasis with Circular External Fixation for the Treatment of Posttraumatic Ankle Arthritis

Ankle arthrodiastasis provides an alternative surgical treatment of the mild to moderate posttraumatic ankle arthritis. Ankle arthrodesis or ankle implant arthroplasty is usually reserved for the end-stage ankle arthritis and after conservative treatment options have been implicated for a long period of time. Ankle joint destructive procedures are often considered for the older and less active population with strict selected surgical criteria and prolonged rehabilitation. In either ankle joint-sparing or ankle destructive procedures, lower extremity deformity correction will need to be addressed before or at the time of index surgery for the overall patient's successful outcome.

In-Hospital Complications Following Ankle Arthrodesis Versus Ankle Arthroplasty: A Matched Cohort Study

BACKGROUND

Ankle arthrodesis has been the traditional surgical treatment for end-stage hindfoot arthritis. However, utilization of total ankle arthroplasty (TAA) is increasing as surgical techniques and implants have substantially improved. The purpose of this study was to compare the U.S. national rates of perioperative (in-hospital) complications between a statistically matched cohort of patients who underwent either an ankle arthrodesis or a TAA.

METHODS

Data from the 2002 to 2013 Nationwide Inpatient Sample releases were analyzed. The International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) procedure codes were used to identify 4,192 patients treated with TAA (ICD 81.56) and 16,278 treated with ankle arthrodesis (ICD 81.11). ICD-9-CM diagnosis codes were utilized to identify major and minor in-hospital complications, and mortality was determined using the Uniform Bill patient disposition. The arthrodesis and TAA groups were matched with regard to age, sex, race, surgery year, hospital type, comorbidities, adjunctive procedures, and surgical indication. Unadjusted and adjusted in-hospital complication risks were compared between groups using the Fisher exact test and multiple logistic regression analysis.

RESULTS

We were able to statistically match 1,574 patients who underwent a TAA (37.5%) with a patient who underwent arthrodesis. A major in-hospital complication occurred in 8.5% (134) of the 1,574 patients in the ankle arthrodesis group compared with 5.3% (84) of the 1,574 in the TAA group (p < 0.001) whereas a minor complication was found in 4.7% (74) in the ankle arthrodesis group compared with 5.9% (93) in the TAA group (p = 0.14). There were no deaths in either group. After adjusting for case mix, we found that ankle arthrodesis was 1.8 times more likely to be followed by a major complication (odds ratio [OR] = 1.78, 95% confidence interval [CI] = 1.32 to 2.39) whereas the minor complication rate was 29% lower in that group (OR = 0.71, 95% CI = 0.45 to 1.13).

CONCLUSIONS

In a matched cohort of 3,148 patients treated with either TAA or ankle arthrodesis, ankle arthrodesis was associated with a 1.8 times higher risk of a major complication but a 29% lower risk of a minor complication. Our findings are consistent with other studies that have shown TAA to be a safe procedure in the inpatient environment.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Supramalleolar Osteotomy for Tibial Component Malposition in Total Ankle Replacement

BACKGROUND

Persistent pain despite a total ankle replacement is not uncommon. A main source of pain may be an insufficiently balanced ankle. An alternative to the revision of the existing arthroplasty is the use of a corrective osteotomy of the distal tibia, above the stable implant. This strictly extraarticular procedure preserves the integrity of the replaced joint. The aim of this study was to review a series of patients in whom a corrective supramalleolar osteotomy was performed to realign a varus misaligned tibial component in total ankle replacement. We hypothesized that the supramalleolar osteotomy would correct the malpositioned tibial component, resulting in pain relief and improvement of function.

METHODS

Twenty-two patients (9 male, 13 female; mean age, 62.6 years; range, 44.7-80) were treated with a supramalleolar osteotomy to correct a painful ankle with a varus malpositioned tibial component. Prospectively recorded radiologic and clinical outcome data as well as complications and reoperations were analyzed.

RESULTS

The tibial anterior surface angle significantly changed from 85.2 ± 2.5 degrees preoperatively to 91.4 ± 2.9 degrees postoperatively ( P < .0001), the American Orthopaedic Foot & Ankle Society hindfoot score significantly increased from 46 ± 14 to 66 ± 16 points ( P < .0001) and the patient's pain score measured with the visual analog scale significantly decreased from 5.8 ± 1.9 to 3.3 ± 2.4 ( P < .001). No statistical difference was found in the tibial lateral surface angle and the range of motion of the ankle when comparing the preoperative to the postoperative measurements. The osteotomy healed in all but 3 patients on first attempt. Fifteen patients (68%) were (very) satisfied, 4 moderately satisfied, and 3 patients were not satisfied with the result.

CONCLUSION

The supramalleolar osteotomy was found to be a reliable treatment option for correcting the varus misaligned tibial component in a painful replaced ankle. However, nonunion (14%) should be mentioned as a possible complication of this surgery. Nonetheless, as a strictly extraarticular procedure, it did not compromise function of the previously replaced ankle, and it was shown to relieve pain without having to have revised a well-fixed ankle arthroplasty.

LEVEL OF EVIDENCE

Level IV, case series.

Revision of Stemmed Agility Implants

Total ankle arthroplasty has advanced rapidly in the last 20 years. Early agility implants enjoyed improved survivability compared with more archaic total ankle implants. When talar subsidence occurs, the revision options include a stemmed component to improve stability by spanning the subtalar joint. Removal and revision of these stemmed components can be difficult because of ingrowth and bone loss.

Management of Talar Component Subsidence

Component subsidence has been found to be the top complication that leads to failure of the total ankle arthroplasty (TAA). The cause of subsidence formation is unclear, and is multifactorial. Talar subsidence is more frequently met than tibial subsidence, and the subsequent big bone loss is demanding to handle. As a revision treatment option, neither a revision TAA nor a salvage ankle and/or hindfoot arthrodesis procedure is easy to perform or can obtain a definite outcome. The Salto XT can be used to treat most of the TAA systems available for use in the United States with acceptable short-term outcomes.

Dealing with the Stiff Ankle: Preoperative and Late Occurrence

In patients with a stiff ankle replacement, appropriate resection of scarred capsular structures, hypertrophic bone debridement, and careful release of tendons should be performed to achieve good outcomes. Appropriately sized and correctly implanted components are required to restore ankle function to as normal as possible. Although not proven, the better a total ankle replacement is balanced, the less likely scar and heterotopic bone formation will occur. In patients with a stiff and painful ankle replacement, a preoperative diagnostic workup is mandatory to understand the underlying pathologic process and plan appropriate treatment. All underlying causes should be addressed.

Are periprosthetic osteolytic lesions in ankle worth bone grafting?

BACKGROUND

We retrospectively evaluated the medium-term follow-up of bone grafting due to periprosthetic osteolytic lesions in ankles.

METHODS

34 ankles (32 patients) with total ankle arthroplasty (TAA) underwent re operation. Indications were large periprosthetic osteolytic lesions or continuous growing of the lesions. The osteolytic lesions were imaged by CT before reoperation and once a year after that. The mean CT follow-up after re operation was 3.8 years (range, 2-6.2 years). Patient's clinical outcome was also monitored.

RESULTS

Osteolysis continued to progress in 44 bone grafted lesions (68%) in CT follow-up. Pain (p=0.04) and location of the lesion (p=0.03) were associated with progression of osteolysis. In 18 bone grafted osteolytic lesions (28%) the radiological survival remained excellent. 25 out of 34 ankles showed improvement of the function after bone grafting.

CONCLUSIONS

There is no established treatment protocol for osteolysis around TAA. Bone grafting is one alternative in the treatment of osteolytic lesions.

Posterior Arthroscopic Subtalar Arthrodesis: Clinical and Radiologic Review of 19 Cases

Arthroscopic subtalar arthrodesis has recently gained popularity in the treatment of primary subtalar or post-traumatic arthritis, coalition, or inflammatory diseases with subtalar arthritis. The present study reports the clinical and radiologic results of 19 patients (19 feet) who underwent posterior arthroscopic subtalar arthrodesis using 2 posterior portals. A total of 19 posterior arthroscopic subtalar arthrodeses (minimum follow-up of 24 months) performed without a bone graft and with 2 parallel screws were prospectively evaluated. The fusion rate was 94% (mean time to fusion 9.8 weeks). Modified American Orthopaedic Foot and Ankle Society ankle-hindfoot scale score (maximum 94 points) improved significantly from 43 to 80 points and the visual analog scale for pain score improved from 7.6 to 1.2. The 12-item short-form physical and mental scores at the last follow-up point were 52.5 and 56.4, respectively. One (5.3%) patient underwent open repeat fusion for nonunion, 2 (10.5%) patients required a second procedure for implant removal, and 1 (5.3%) experienced reversible neuropraxia. In conclusion, posterior arthroscopic subtalar arthrodesis is a safe technique with a good union rate and a small number of complications in patients with no or very little hindfoot deformity.

The painful total ankle arthroplasty: a diagnostic and treatment algorithm

The last decade has seen a considerable increase in the use of in total ankle arthroplasty (TAA) to treat patients with end-stage arthritis of the knee. However, the longevity of the implants is still far from that of total knee and hip arthroplasties. The aim of this review is to outline a diagnostic and treatment algorithm for the painful TAA to be used when considering revision surgery. Cite this article: Bone Joint J 2017;99-B:5-11.

Custom-made total ankle arthroplasty for the salvage of major talar bone loss

Aims

A failed total ankle arthroplasty (TAA) is often associated with much bone loss. As an alternative to arthrodesis, the surgeon may consider a custom-made talar component to compensate for the bone loss. Our aim in this study was to assess the functional and radiological outcome after the use of such a component at mid- to long-term follow-up.

Patients and Methods

A total of 12 patients (five women and seven men, mean age 53 years; 36 to77) with a failed TAA and a large talar defect underwent a revision procedure using a custom-made talar component. The design of the custom-made components was based on CT scans and standard radiographs, when compared with the contralateral ankle. After the anterior talocalcaneal joint was fused, the talar component was introduced and fixed to the body of the calcaneum.

Results

At a mean follow-up of 6.9 years (1 to 13), 11 ankles were stable with no radiological evidence of loosening. Only one was lost to follow-up. The mean arc of movement was 21° (10° to 35°). A total of nine patients (75%) were satisfied or very satisfied with the outcome, two (17%) were satisfied but with reservations and one (8%) was not satisfied. All but one patient had an improvement in the American Orthopaedic Foot and Ankle Society hindfoot score (p = 0.01). Just one patient developed deep infection, leading to arthrodesis.

Conclusion

A custom-made talar component yielded satisfactory results with regard to function, stability and satisfaction. This should encourage the use of such components as an alternative to arthrodesis of the ankle in patients with a failed TAA. Cite this article: Bone Joint J 2017;99-B:231–6.

Intraoperative Radiation Exposure During Revision Total Ankle Replacement

Intraoperative C-arm image intensification is required for primary total ankle replacement implantation. Significant radiation exposure has been linked to these procedures; however, the radiation exposure during revision total ankle replacement remains unknown. Therefore, we sought to evaluate the radiation exposure encountered during revision total ankle replacement. The data from 41 patients were retrospectively analyzed from a prospective database: 19 Agility(™) to Agility(™); 4 Agility(™) to Custom Agility(™); 9 Agility(™) to INBONE(®) II; 5 Agility(™) to Salto Talaris(®) XT; 2 Scandinavian Total Ankle Replacement Prosthesis to Salto Talaris(®) XT; and 2 INBONE(®) I to INBONE(®) II revision total ankle replacements were performed. Two broad categories were identified: partial revision (Agility(™) to Agility(™), Agility(™) to Custom Agility(™), INBONE(®) I to INBONE(®) II) and complete conversion (Agility(™) to INBONE(®) II, Agility(™) to Salto Talaris(®) XT, Scandinavian Total Ankle Replacement Prosthesis to Salto Talaris(®) XT). The mean radiation exposure per case was significant at 3.49 ± 2.21 mGy. Complete conversions, specifically Agility(™) to INBONE(®) II, exhibited the greatest radiation exposure and C-arm time. Revision implant selection and revision type (complete or partial) directly contributed to radiation exposure. Accordingly, revision systems requiring less radiation exposure are preferable. Surgeons should strive to minimize intraoperative complications and limit additional procedures to those necessary, because both lead to additional radiation exposure.

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.

Total ankle replacement

BACKGROUND

About 1% of adults suffer from painful osteoarthritis of the ankle. The current literature contains no information on the percentage of such patients who derive long-term relief of symptoms from conservative treatment. Advanced ankle osteoarthritis can be treated with non-joint-preserving measures, such as total ankle replacement and ankle fusion.

METHODS

This review is based on selected relevant publications, guidelines from Germany and abroad, and the authors' personal experience.

RESULTS

Before surgery is considered, conservative measures such as physiotherapy and orthopedic aids should be used to the fullest possible extent. No randomized trials have yet been published comparing total ankle replacement with ankle fusion. Total ankle replacement with newer types of prosthesis yields good to very good intermediate-term and long-term results, with mean success rates of up to 90% at 10 years (range, 68-100%). Independent risk factors for the failure of ankle replacement are age over 70 years (odds ratio [OR] 3.84), primary osteoarthritis (OR 7.19), post-traumatic osteoarthritis (OR 6.2), and type of prosthesis (e.g., single hydroxyapatite coating: OR 15.04). The average range of motion of the replaced ankle joint is 25° to 30°, with values as high as 60°.

CONCLUSION

Total ankle replacement is a good treatment option for complete, end-stage ankle arthritis. It can restore joint function and make the patient mobile with little or no pain. There are, however, many contraindications to be taken into account. There is a need for further studies of the biomechanics of arthritic and replaced ankle joints and for long-term follow-up studies of total ankle replacement.

Incidence of Complications During Initial Experience with Revision of the Agility and Agility LP Total Ankle Replacement Systems: A Single Surgeon's Learning Curve Experience

As the frequency in which foot and ankle surgeons are performing primary total ankle replacement (TAR) continues to build, revision TAR will likely become more commonplace, creating a need for an established benchmark by which to evaluate the safety of revision TAR as determined by the incidence of complications. Currently, no published data exist on the incidence of intraoperative and early postoperative complications during revision of the Agility or Agility LP Total Ankle Replacement Systems during the surgeon learning curve period; therefore, the authors sought to determine this incidence during the senior author's learning curve period.

Radiographic Outcomes of Preoperative CT Scan-Derived Patient-Specific Total Ankle Arthroplasty

BACKGROUND

Preoperative computer navigation and patient-specific instrumentation have had promising results in total knee arthroplasty and in a previous cadaveric total ankle arthroplasty (TAA) study. Potential benefits of patient-specific guides include improved implant alignment and decreased surgical time. The purpose of this retrospective case series was to evaluate the accuracy, reproducibility, and limitations of TAA tibia and talar implant placement and radiographic alignment using preoperative computed tomography (CT) scan-derived instrumentation in a clinical setting.

METHODS

Between 2012 and 2014, 42 consecutive TAA cases in 42 patients using preoperative CT scan-derived patient-specific plans and guides (PROPHECY, Wright Medical Technology, Memphis TN) were reviewed from a single center of foot and ankle fellowship-trained orthopaedic surgeons. TAA implants used included 29 intramedullary referencing implants (INBONE II, Wright Medical Technology) and 13 low-profile tibia and talar resurfacing implants (Infinity, Wright Medical Technology). All patients had standardized preoperative CT scans before surgery that were used to create custom surgical plans and 3-dimensional solid cutting guides and models. All patients had a minimum 3-month follow-up with weightbearing postoperative radiographs. Patient demographics were recorded, and coronal and sagittal alignments were compared among weightbearing preoperative radiographs, CT scan-derived surgical plans, and weightbearing postoperative radiographs using a digital picture archiving and communication system.

RESULTS

Average age for all patients was 63 ± 9 years, with a body mass index of 29.8 ± 5.9. Average total surgical time for all TAAs was 100 ± 11 minutes, with Infinity TAAs taking less time than INBONE II TAAs (92 vs 104 minutes; P < .05). Average preoperative coronal alignment was 1.9 degrees varus ± 6.4 (range, 14 degrees valgus to 10 degrees varus). Postoperative weightbearing alignments for all TAA cases were within ±3° of the predicted coronal and sagittal alignments from the CT scan-derived surgical plans. There were no significant differences in pre- or postoperative weightbearing alignments between INBONE II and Infinity TAA cases. Neutral coronal and sagittal alignments were obtained for all TAA cases regardless of preoperative deformity. Patient-specific surgical plans were accurate to within 1 size for tibia and talar implants used. Surgical plans predicted the actual tibia implant size used in 100% of INBONE II cases and 92% of Infinity cases. Plans were less accurate for talar implants and predicted the actual talar implant size used in 76% of INBONE II cases and 46% of Infinity cases. In all cases of predicted tibia or talar size mismatch, surgical plans predicted 1 implant size larger than actually used.

CONCLUSIONS

Results from this study provide early clinical evidence that preoperative CT scan-derived patient-specific surgical plans and guides can help provide accurate and reproducible TAA radiographic alignments. Talar implant sizing was not as accurate due to individual surgeon preference regarding the extent of gutter debridement. Similar to other modern computer navigation and patient-specific instrumentation systems, final coronal and sagittal alignments were within 3 degrees of the predicted surgical plans, and sizing was accurate within 1 implant size. Future studies are warranted to investigate the clinical and functional implications of patient-specific TAA and the overall cost-effectiveness of this technique.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The Salto Talaris XT Revision Ankle Prosthesis

The Salto Talaris XT Revision Ankle Prosthesis is an anatomically designed fixed-bearing prosthesis available in the United States based on the design of previous Salto systems. The Salto Talaris XT Revision Ankle Prosthesis design optimizes surface area, cortical contact, and ultrahigh-molecular-weight polyethylene conformity. Two tibial component designs, both with the same base plate dimensions, are available, the standard conical fixation plug affixed to a short keel and a long-stemmed version. The author presents an overview of the Salto Talaris XT Revision Ankle Prosthesis surgical technique and pearls for successful application.