The management of failed ankle replacement

Custom Patient-Specific 3D-Printed Titanium Truss Tibiotalocalcaneal Arthrodesis Implants for Failed Total Ankle Replacements: Classification, Technical Tips, and Treatment Algorithm

BACKGROUND

The management of failed total ankle replacements, with significant loss of bone stock, is challenging with high rates of complications and associated morbidity. Recent technological advances have enabled the development of patient-customized 3D-printed titanium truss arthrodesis implants, which offer an alternative salvage option for failed total ankle replacements.

METHODS

A prospective observational study was performed of 6 cases of failed total ankle replacements that were managed using custom patient-specific 3D-printed titanium truss arthrodesis implants. Technical tips, classification, and a treatment algorithm were developed based on our initial experience.

RESULTS

Between November 2018 and March 2022, 6 patients underwent arthrodesis for failed total ankle replacements. Follow-up was available for all cases. The mean follow-up was 3.0 years (range 1-4.5). The mean MOXFQ Index improved from 73.1 to 32.3 (P < .05). The mean EQ-5D-5L Index improved from 0.366 to 0.743 (P < .05) and the EQ-VAS also improved from 53.0 to 63.3 (P = .36). The mean VAS-Pain score at final follow-up was 27.5. There were no cases of nonunion. None of the patients were smokers. The overall complication rate was 50%. Two patients returned to surgery: one for wound washout following TAR explantation and a second for removal of metalwork 2 years following surgery for a prosthetic joint infection secondary to hematogenous spread. No patients underwent revision fixation or amputation.

CONCLUSION

Custom patient-specific 3D-printed titanium truss arthrodesis implants are a viable treatment option for failed total ankle replacements.

A numerical investigation of stress, strain, and bone density changes due to bone remodelling in the talus bone following total ankle arthroplasty

Total ankle arthroplasty is the gold standard surgical treatment for severe ankle arthritis and fracture. However, revision surgeries due to the in vivo failure of the ankle implant are a serious concern. Extreme bone density loss due to bone remodelling is one of the main reasons for in situ implant loosening, with aseptic loosening of the talar component being one of the primary reasons for total ankle arthroplasty revisions. This study is aimed at determining the performance and potential causes of failure of the talar component. Herein, we investigated the stress, strain, and bone density changes that take place in the talus bone during the first 6 months of bone remodelling due to the total ankle arthroplasty procedure. Computed tomography scans were used to generate the 3D geometry used in the finite element (FE) model of the Intact and implanted ankle. The Scandinavian Total Ankle Replacement (STAR™) CAD files were generated, and virtual placement within bone models was done following surgical guidelines. The dorsiflexion physiological loading condition was investigated. The cortical region of the talus bone was found to demonstrate the highest values of stress (5.02 MPa). Next, the adaptive bone remodelling theory was used to predict bone density changes over the initial 6-month post-surgery. A significant change in bone density was observed in the talus bone due to bone remodelling. The observed quantitative changes in talus bone density over 6-month period underscore potential implications for implant stability and fracture susceptibility. These findings emphasise the importance of considering such biomechanical factors in ankle implant design and clinical management.

Comparing Rates of Radiographic Baseplate Loosening Between Cement and Cementless INFINITY Total Ankle Prostheses

INTRODUCTION

Total ankle replacement is indicated for end-stage ankle osteoarthritis. Periprosthetic radiolucency, from separation between the bone and implant, is suggested to be indicative of potential prosthesis failure risk. Anchoring implants with cement may mitigate this. This study aimed to compare rates of periprosthetic radiolucency between patients with cement-affixed and cementless implants.

METHODS

A retrospective analysis was performed on 28 patients who underwent total ankle replacement with the INFINITY Total Ankle System (Wright Medical, Memphis, Tennessee) implant between January 2016 and May 2022. Anteroposterior, mortise, and lateral ankle X-rays were reviewed by 2 independent reviewers for tibiotalar angle, talar tilt, and periprosthetic radiolucency. The Wilcoxon rank-sum test and chi-square test were performed.

RESULTS

The incidence of periprosthetic radiolucency at the most recent follow-up did not significantly differ between cement and cementless groups (57.1% in both groups, P = 1.0). Follow-up tibiotalar and talar tilt angles were not significantly different (P > .51 for all comparisons).

CONCLUSIONS

Patients with cemented implants had a similar incidence of periprosthetic radiolucency compared with patients with cementless prostheses. Understanding of long-term clinical outcomes will help inform optimal operative approaches for ankle prostheses.

LEVELS OF EVIDENCE

Therapeutic, Level III, Retrospective cohort study.

Revision of total ankle arthroplasty: Survival and medium-term functional results

BACKGROUND

The objective of this study was to analyze the results and survivorship of total ankle arthroplasty (TAA) revision surgery with standard (Salto Talaris®) or revision (Salto Talaris XT®) implants.

METHODS

Between January 2005 and December 2017, all patients undergoing TAA revision at our hospital were included. Indications for revision, type of surgery performed, improvement in function assessed with the AOFAS score, occurrence of complications and implant survival at last follow-up were analyzed.

RESULTS

In the end, 25 TAA patients who had undergone revision (11 unipolar, 14 bipolar) were included. The mean follow-up time was 5.1 ± 1.9 years. At the last follow-up, function was improved compared to the preoperative AOFAS score (51.3 ± 17.5 vs. 83.5 ± 10.1; p < .001), but not plantar flexion (17.5 ± 5.7 vs. 15.4 ± 7.1; p = 0.28) or dorsal flexion (7 ± 5.6 vs. 8.3 ± 4.9; p = 0.3). Complications occurred in six patients (24 %) that led to reoperation: three infections, one lateral impingement, one implant malposition, and one hindfoot alignment disorder. At the last follow-up, implant survival was 96 %, but the probability of survival without reoperation was 78.7 ± 8.5 % at 4 years.

CONCLUSION

TAA revision by arthroplasty is feasible, produces good functional results in the medium term, but has a high risk of complications. The challenge of revision TAA is managing the loss of bone stock and anchoring the new implants.

Total Ankle Replacement Infections: A Systematic Review of the Literature

Periprosthetic infection (PJI) after TAR is a serious complication, often requiring further surgery, including revision arthroplasty, conversion to ankle arthrodesis, or even amputation. This systematic review aims to summarize the current evidence on the management of TAR PJI and provide a comprehensive overview of this topic, especially from an epidemiologic point of view. Three different databases (PubMed, Scopus, and Web of Science) were searched for relevant articles, and further references were obtained by cross-referencing. Seventy-one studies met the inclusion criteria, reporting on cases of TAR PJI. A total of 298 PJIs were retrieved. The mean incidence of PJI was 3.8% (range 0.2-26.1%). Furthermore, 53 (17.8%) were acute PJIs, whereas most of them (156, 52.3%) were late PJIs. Most of the studies were heterogeneous regarding the treatment protocols used, with a two-stage approach performed in most of the cases (107, 35.9%). While the prevalence of ankle PJI remains low, it is potentially one of the most devastating complications of TAR. This review highlights the lack of strong literature regarding TAR infections, thus highlighting a need for multicentric studies with homogeneous data regarding the treatment of ankle PJI to better understand outcomes.

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.

Management of Periprosthetic Bone Cysts After Total Ankle Arthroplasty

Modern improvements in total ankle arthroplasty (TAA) have increased the performance of this procedure for treatment of end-stage ankle arthritis. A common finding after TAA is the formation of periprosthetic bone cysts, which can be clinically silent or result in TAA failure. The exact cause of periprosthetic bones cysts has not been established, but major theories are related to osteolysis secondary to implant wear, micromotion, and stress shielding. Treatment can be nonoperative with clinical observation for small, asymptomatic cysts. Large, progressive, and symptomatic cysts often merit surgical treatment with debridement and grafting, revision TAA, or salvage arthrodesis.

Does a fibula-sparing approach improve outcomes in tibiotalocalcaneal arthrodesis?

BACKGROUND

Tibiotalocalcaneal (TTC) arthrodesis is considered a salvage procedure for either complex deformity or arthritis about the hindfoot, and can be performed via fibula-resection (FR) or fibula-sparing (FS) approaches. The primary aim of this study was to investigate differences in outcomes in FR versus FS TTC arthrodeses.

METHODS

This was a retrospective cohort study reviewing outcomes of TTC arthrodesis at a single institution. Patients who underwent a TTC arthrodesis from 2005 to 2017 and had minimum two-year follow-up were included. Preoperative diagnosis, pre- and post-operative radiographic coronal alignment, fixation methods, and complications were compared between groups.

RESULTS

107 patients (110 ankles) underwent TTC arthrodesis, with a mean age of 57.0 years (sd, 14.0 years). The mean clinical follow-up was 50.7 months (range, 24-146) and mean radiographic follow-up was 45.8 months (range, 6-146 months). Pre-operative diagnoses included arthritis (N = 40), prior non-union (N = 21), Charcot neuro-arthropathy (N = 15), failed total ankle arthroplasty (N = 15) and avascular necrosis of the talus (N = 19). Sixty-nine ankles comprised the FS group and 41 comprised the FR group. There was no significant difference in the non-union rate between groups (29% FR vs 38% FS, p = 0.37), complication rate (59% FR vs 64% FS, p = 0.59), or post-operative coronal standing radiographic alignment (89.6 degrees FR, 90.5 degrees FS, p = 0.26). Logistic regression analyses demonstrated a pre-operative diagnosis of failed TAA was associated with post-operative nonunion (OR:3.41,CI:1.13-11.04,p = 0.03). Pre-operative indication for TTC arthrodesis of arthritis alone was associated with a decreased risk of non-union (OR:0.27,CI:0.11-0.62,p = 0.002).

CONCLUSION

TTC arthrodesis is a successful surgical option for complex hindfoot deformity, arthritis, and limb salvage regardless of surgical approach. We did not detect a difference in the union rate, incidence of complications, or coronal plane radiographic alignment in fibula-sparing versus fibula-resection constructs. Patients with a pre-operative indication for surgery of arthritis may be at decreased risk of developing non-union.

LEVEL OF EVIDENCE

III - Retrospective cohort study.

Dynamic finite element analyses to compare the influences of customised total talar replacement and total ankle arthroplasty on foot biomechanics during gait

Objective, Total talar replacement (TTR) using a customised talus prosthesis is an emerging surgical alternative to conventional total ankle arthroplasty (TAA) for treating ankle problems. Upon satisfying clinical reports in the literature, this study explored the advantages of TTR in restoring foot biomechanics during walking compared with TAA through computational simulations.Methods, A dynamic finite element foot model was built from the MRIs of a healthy participant and modified into two implanted counterparts (TTR and TAA) by incorporating the corresponding prosthetic components into the ankle joint. Twenty bony parts, thirty-nine ligament/tendon units, nine muscle contractors, and bulk soft tissue were included in the intact foot model. The TTR prosthesis was reconstructed from the mirror image data of the participant's contralateral talus and the TAA prosthesis was modelled by reproducing the Scandinavian ankle replacement procedure in the model assembly. The model was meshed with explicit deformable elements and validated against existing experimental studies that have assessed specific walking scenarios. Simulations were performed using the boundary conditions (time-variant matrix of muscle forces, segment orientation, and ground reaction forces) derived from motion capture analyses and musculoskeletal modelling of the participant's walking gait. Outcome variables, including foot kinematics, joint loading, and plantar pressure were reported and compared among the three model conditions.

RESULTS

Linear regression indicated a better agreement between the TTR model and intact foot model in plots of joint motions and foot segment movements during walking (R² ​= ​0.721-0.993) than between the TAA and intact foot (R² ​= ​0.623-0.990). TAA reduced talocrural excursion by 21.36%-31.92% and increased (MTP) dorsiflexion by 3.03%. Compared with the intact foot, TTR and TAA increased the midtarsal joint contact force by 17.92% and 10.73% respectively. The proximal-to-distal force transmission within the midfoot was shifted to the lateral column in TTR (94.52% or 210.54 ​N higher) while concentrated on the medial column in TAA (41.58% or 27.55 ​N higher). The TTR produced a plantar pressure map similar to that of the intact foot. TAA caused the plantar pressure centre to drift medially and increased the peak forefoot pressure by 7.36% in the late stance.

CONCLUSION

The TTR better reproduced the foot joint motions, segment movements, and plantar pressure map of an intact foot during walking. TAA reduced ankle mobility while increasing movement of the adjacent joints and forefoot plantar pressure. Both implant methods changed force transmission within the midfoot during gait progression.The translational potential of this article Our work is one of the few to report foot segment movements and the internal loading status of implanted ankles during a dynamic locomotion task. These outcomes partially support the conjecture that TTR is a prospective surgical alternative for pathological ankles from a biomechanical perspective. This study paves the way for further clinical investigations and systematic statistics to confirm the effects of TTR on functional joint recovery.

Is debridement really the best we can do for periprosthetic joint infections following total ankle replacements? A systematic review and meta-analysis

BACKGROUND

Ankle periprosthetic joint infections are rising in number, but an evidence-based gold standard treatment has not been defined yet.

METHODS

We made a systematic review about the operative treatment of infections following total ankle arthroplasty. Proportional meta-analysis was used to summarize effects of the surgical techniques included. Primary outcome of this study was infection eradication, followed by complications, re-interventions, amputation rates and functions.

RESULTS

We included six studies(113 patients) reporting 6 types of surgical interventions, mostly irrigation and debridement (35.4%) and two-stage revisions (24.8%). No differences among all analyzed techniques were found in the infection eradication outcome as well as in the secondary outcomes. Patients receiving a permanent spacer are most likely to end up with amputation.

CONCLUSIONS

Literature dealing with infections after total ankle replacement is currently composed by few low-quality articles. The overlapping of confidence intervals related to all analyzed interventions showed no superiority of either technique.

LEVEL OF EVIDENCE

III.

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.

Malalignment of the total ankle replacement increases peak contact stresses on the bone-implant interface: a finite element analysis

Introduction

Malalignment of the Total Ankle Replacement (TAR) has often been postulated as the main reason for the high incidence of TAR failure. As the ankle joint has a small contact area, stresses are typically high, and malalignment may lead to non-homogeneous stress distributions, including stress peaks that may initiate failure. This study aims to elucidate the effect of TAR malalignment on the contact stresses on the bone-implant interface, thereby gaining more understanding of the potential role of malalignment in TAR failure.

Methods

Finite Element (FE) models of the neutrally aligned as well as malaligned CCI (Ceramic Coated Implant) Evolution TAR implant (Van Straten Medical) were developed. The CCI components were virtually inserted in a generic three-dimensional (3D) reconstruction of the tibia and talus. The tibial and talar TAR components were placed in neutral alignment and in 5° and 10° varus, valgus, anterior and posterior malalignment. Loading conditions of the terminal stance phase of the gait cycle were applied. Peak contact pressure and shear stress at the bone-implant interface were simulated and stress distributions on the bone-implant interface were visualized.

Results

In the neutral position, a peak contact pressure and shear stress of respectively 98.4 MPa and 31.9 MPa were found on the tibial bone-implant interface. For the talar bone-implant interface, this was respectively 68.2 MPa and 39.0 MPa. TAR malalignment increases peak contact pressure and shear stress on the bone-implant interface. The highest peak contact pressure of 177 MPa was found for the 10° valgus malaligned tibial component, and the highest shear stress of 98.5 MPa was found for the 10° posterior malaligned talar model. High contact stresses were mainly located at the edges of the bone-implant interface and the fixation pegs of the talar component.

Conclusions

The current study demonstrates that TAR malalignment leads to increased peak stresses. High peak stresses could contribute to bone damage and subsequently reduced implant fixation, micromotion, and loosening. Further research is needed to investigate the relationship between increased contact stresses at the bone-implant interface and TAR failure.

The Most-Cited Ankle Arthroplasty Implant Articles

Background:

Citation analysis is a useful way of evaluating the impact, importance, and merit of articles within a medical specialty. Our study identified and analyzed the most-cited articles on ankle arthroplasty implants to evaluate their importance in the field of ankle arthroplasty research.

Methods:

Using the keywords “ankle arthroplasty” and “ankle replacement” and the search period 1970-2021, we found 3728 articles on ankle arthroplasty implants in the Scopus, Web of Science, and MEDLINE/PubMed databases. We included original articles, reviews, clinical trials, and case reports in the study. We retrieved the 50 most-cited articles published during the time frame and then screened them for studies of specific ankle arthroplasty implants and their postoperative outcomes. We also recorded and analyzed the articles’ subjects, authorship, journals, countries of origin, and years of publication.

Results:

The 50 most-cited articles were published between 1983 and 2014, with the majority (33) published between 2000 and 2010. They generated 9012 citations in the literature. The most-cited study accounted for 497 citations; the mean number of citations per article was 180.24 ± 76.24. Twenty-three (46%) of the articles addressed postoperative outcomes following a specific type of arthroplasty implant. Arthroplasty implant studies accounted for 4726 citations, or 52.4% of the citations of the 50 articles. The most frequently studied arthroplasty implant was STAR (15), followed by Agility (7), Buechel Pappas (5), and Salto (4). STAR accounted for 3311 citations, or 37% of the total citations of the 50 articles.

Conclusion:

Ankle arthroplasty research has made great progress in the past 2 decades, particularly in the area of postoperative outcomes of specific ankle implants, but continued research and publication on additional arthroplasty implants should become a priority.

Level of Evidence:

Level V, Review Article.

The King's Sliding Hindfoot Osteotomy for the Treatment of Talus Body Defects-Results of a New Technique in Tibiotalocalcaneal Arthrodesis

Bone loss after avascular necrosis of the talus secondary to acute traumatic or chronic pathologies often requires surgical reconstruction. This study reports the early results of a sliding oblique hindfoot osteotomy for salvage procedures combined with tibiotalar arthrodesis to achieve a well-aligned, painless, plantigrade foot. All patients presenting to our institution with severe talus body defects requiring corrective surgery between January 2016 and August 2020 were included. An oblique osteotomy of the diseased talus was performed to correct anterior talus subluxation and prevent excessive loss of height at the tibiotalar apposition and to correct varus-valgus deformity. A retrograde hindfoot nail was used for intramedullary tibiotalocalcaneal arthrodesis. Patients were prospectively followed. Primary outcomes included assessment of mobility and union at 6 months. Secondary outcomes included 30-day postoperative complications, patient satisfaction and change in American Orthopaedic Foot & Ankle Society (AOFAS) score at 1-year postoperation. Nine patients underwent this procedure with a mean follow-up of 18 months (4-36 months). Average age was 66 (58-81) years. Mean body mass index was 33.7 (22-38) kg/m². All patients went on to fusion and were ambulating at 6 months (n = 8). At 1 year, the mean improvement in AOFAS was 28.9 points (p < .05) (n = 7) and all patients were satisfied with the outcome of their treatment. This technique represents an alternative to conventional hindfoot salvage techniques showing predictable outcomes in complex hindfoot deformity with talar body collapse and anterior subluxation. Further quantitative studies are needed to define if this technique minimizes limb shortening/limb-length discrepancies when compared to traditional horizontal cuts.

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.

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.

Total ankle arthroplasty

AIMS

We report the medium-term outcomes of a consecutive series of 118 Zenith total ankle arthroplasties (TAAs) from a single, non-designer centre.

METHODS

Between December 2010 and May 2016, 118 consecutive Zenith prostheses were implanted in 114 patients. Demographic, clinical, and patient-reported outcome measures (PROMs) data were collected. The endpoint of the study was failure of the implant requiring revision of one or all of the components. Kaplan-Meier survival curves were generated with 95% confidence intervals (CIs) and the rate of failure calculated for each year.

RESULTS

Eight patients (ten ankles) died during follow-up, but none required revision. Of the surviving 106 patients (108 ankles: rheumatoid arthritis (RA), n = 15; osteoarthritis (OA), n = 93), 38 were women and 68 were men, with a mean age of 68.2 years (48 to 86) at the time of surgery. Mean follow-up was 5.1 years (2.1 to 9.0). A total of ten implants failed (8.5%), thus requiring revision. The implant survival at seven years, using revision as an endpoint, was 88.2% (95% CI 100% to 72.9%). There was a mean improvement in Manchester-Oxford Foot and Ankle Questionnaire (MOXFQ) from 85.0 to 32.8 and visual analogue scale (VAS) scores from 7.0 to 3.2, and overall satisfaction was 89%. The three commonest complications were malleolar fracture (14.4%, n = 17), wound healing (13.6%, n = 16), and superficial infection (12.7%, n = 15). The commonest reason for revision was aseptic loosening. No patients in our study were revised for deep infection.

CONCLUSION

Our results show that Zenith survival rates are comparable with those in the literature for other implants and in the National Joint Registry (NJR). Overall patient satisfaction was high as were functional outcomes. However, the data highlight potential complications associated with this surgery. The authors believe that these figures support ankle arthroplasty as an option in the treatment of ankle arthritis. Cite this article: Bone Joint J 2021;103-B(4):696-703.

Clinical Effectiveness of Treatment Strategies for Prosthetic Joint Infection Following Total Ankle Replacement: A Systematic Review and Meta-analysis

Prosthetic joint infection (PJI) after total ankle replacement (TAR) is a challenging complication, which often requires debridement and implant retention (DAIR) with or without polyethylene exchange, revision surgery, implantation of a cement spacer, conversion to arthrodesis, or even amputation. The optimum treatment for ankle PJI is not well established. We conducted a systematic review and meta-analysis to compare the clinical effectiveness of various treatment strategies for infected ankle prostheses. We searched MEDLINE, Embase, Web of Science, and the Cochrane Library up to December 2018 for studies evaluating the impact of treatment in patient populations with infected ankle prostheses following TAR. Binary data were pooled after arcsine transformation. Six citations comprising 17 observational design comparisons were included. The reinfection rates (95% confidence intervals) for DAIR with or without polyethylene exchange, 1-stage revision, 2-stage revision, cement spacer, and arthrodesis were 39.8% (24.4 to 56.1), 0.0% (0.0 to 78.7), 0.0% (0.0 to 8.5), 0.2% (0.0 to 17.9), and 13.6% (0.0 to 45.8), respectively. Rates of amputation for DAIR with or without polyethylene exchange and cement spacer were 5.6% (0.0 to 16.9) and 22.2% (6.3 to 54.7), respectively. Measures of function, pain, and satisfaction could not be compared because of limited data. One- and 2-stage revision strategies seem to be associated with the lowest reinfection rates, but these findings are based on limited data. Arthrodesis and DAIR with or without polyethylene exchange appear to be commonly used in treating infected ankle prosthesis, but are associated with poor infection control. Clear gaps exist in the literature, and further research is warranted to evaluate treatment strategies for infected ankle prosthesis.

Salvage arthrodesis for infected ankle fractures with segmental bone-loss using Ilizarov concepts: a prospective study

PURPOSE

Complex ankle fractures accompanied with infection and segmental bone loss are a worrying issue. This prospective study was conducted to explore the effectiveness of using Ilizarov concepts in achieving salvage arthrodesis and reconstructing post-debridement defects in such complicated scenarios.

METHODS

A total of 44 consecutive patients (mean age 35.61 ± 8.57 years, 30 males, 44 feet) of post-traumatic infected ankle fractures, who met our selection criteria, were enrolled and subjected to radical debridement and salvage arthrodesis using the bifocal bone transport concepts of Ilizarov. All patients were treated between 2012 and 2017 either by acute shortening compression of the arthrodesis site with re-lengthening (ASRL) through the created proximal metaphyseal osteotomy (group I, n = 20) or by gradual bone transport (BT) through the proximal osteotomy with gradual closure of the distal ankle defect (group II, n = 24). Plain-radiographs were used for radiological assessment. Clinically, the outcomes were objectively graded according to the Hawkins criteria, while subjectively the patients reported their satisfaction on a 1-5 points acceptance scale.

RESULTS

The mean follow-up was 37.16 ± 5.31 (30-48 months). Successful fusion was achieved in 43/44 patients, with a significantly (P < 0.05) lesser needs for bone-grafting in favour of group II. The results were good in 32 cases, fair in 11, and poor in a single case with no significant difference between the two groups. The acceptance scores were significantly (P < 0.05) superior in group II (3.08 ± 1.1 points) than that group I (2.25 ± 1.4 points).

CONCLUSIONS

Bifocal bone transport is effective in salvaging troublesome infected ankle fractures with bone loss. BT is more comprehensive and acceptable than ASRL with lesser needs for bone grafting.

The role of external fixation in the management of infected avascular necrosis after traumatic talus fractures

PURPOSE

Avascular necrosis (AVN) after fractures of the talus is a distinct and challenging clinical entity that is associated with poor outcomes. Although several articles are published on the management of posttraumatic AVN of the talus, very little is known about the management of infected AVN after talus fractures. Therefore, three cases of infected AVN were treated successfully by extensive debridement, external fixation and arthrodesis.

METHODS

Three cases of infected AVN of the talus were encountered after a mean of 3 months (range 2-6 months) after initial reconstructive surgery. Suspected infection was confirmed by positron emission tomography scan (PET-CT). Management involved extensive debridement, PMMA cement if necessary and final fusion using medial external fixator, accompanied by culture guided antibiotics. Functional outcome was assessed using the Foot Function Index (FFI) and the American Orthopaedic Foot and Ankle Society hindfoot score (AOFAS). Quality of life (QOL) was measured by the EuroQol-5D (EQ-5D).

RESULTS

After a mean follow up of 24 months (range 13-29), FFI index scores ranged from poor to good (23, 50, 56) with similar AOFAS scores indicating poor to fair functional outcome (38, 41, 71). The EQ-5D score was 0.78. Overall patient satisfaction was high with a mean VAS of 8.3 (range 8-9).

CONCLUSION

Infected talar AVN is a rare condition associated with severe long-term morbidity in term of joint function. The authors recommend extensive debridement and arthrodesis by means of external fixation, followed by post-operative culture-guided antibiotics for the treatment of infected avascular necrosis of traumatic talar fractures. Shared decision-making and expectation management are of crucial importance and may lead to high patient satisfaction despite low functional outcomes.

LEVEL OF EVIDENCE

IV, Retrospective case series.

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.

Ankle Arthrodesis With Structural Grafts Can Work for the Salvage of Failed Total Ankle Arthroplasty

Background. Treatment options after failed total ankle arthroplasty (TAA) are limited. This study reports midterm outcomes and radiographic results in a single-surgeon group of patients who have undergone ankle arthrodesis with intramedullary nail fixation and structural allograft augmentation following failed TAA. Methods. A retrospective review on patients who underwent failed TAA revision with structural femoral head allograft and intramedullary tibiotalocalcaneal (TTC) nail fixation was completed. Foot Function Index (FFI), American Orthopaedic Foot & Ankle Society (AOFAS) outcome scores, and radiographs were obtained at each visit with 5-year follow-up. Results. Five patients were followed to an average of 5.2 years (range 4.7-5.6). Enrollment FFI was 34.82 (range 8.82-75.88); at midterm follow-up it was 20.42 (range 0-35.38). Enrollment AOFAS scores averaged 66.6 (range 61-77); at midterm follow-up it was 70.33 (range 54-88). Radiographs showed union in 4 of 5 patients at enrollment and 2 of 3 patients at midterm. Conclusions. Utilization of TTC fusion with femoral head allograft is a salvage technique that can produce a functional limb salvage. Our results show continued improvement in patient-reported outcomes, with preservation of limb length and reasonable union rate. Levels of Evidence: Therapeutic, Level II: Prospective, comparative trial.

Ankle fusion after failed ankle replacement in rheumatic and non-rheumatic patients

BACKGROUND

With longer follow-up, survival rate of total ankle replacements (TAR) diminishes. It is therefore important to have a reliable fall-back option in case of failed TAR. Revision arthroplasty is often impossible because of loss of bonestock or infection. Conversion to ankle fusion is then indicated. We investigated the clinical, radiographic and patient reported results for fusion after failed TAR in a consecutive group of patients. We concentrated on the influence of inflammatory joint disease (IJD) on union rate.

METHODS

Patient files and radiographic images of 46 consecutive patients (47 ankles) were reviewed. There were 22 patients with IJD. Fixation methods included; anterior plating, blade plate fixation, intramedullary nailing, compression screws and external fixation. Foot and Ankle Outcome Score (FAOS) and Foot and Ankle Ability Measure (FAAM) were used to determine patient related outcomes.

RESULTS

Forty out of 47 ankles (85%) Fused. Union rate in the non-IJD group (96%) was significantly higher compared to the IJD-group (73%, p=0.04). Revisions and complications were more frequent in the IJD group, but numbers were too small to detect a significant difference. Mean PROM scores were: FAOS-symptoms; 68.5, FAOS-pain; 70.3, FAOS-QoL; 43.7, FAOS-ADL; 68.1 and FAAM-ADL; 52.1, with no significant difference between IJD and non-IJD patients.

CONCLUSIONS

IJD-patients have a higher nonunion rate after ankle fusion for failed TAR. However, patient reported outcome is not significantly different between the two groups.

LEVEL OF EVIDENCE

IV, retrospective cohort.

Outcomes Following Total Ankle Arthroplasty: A Review of the Registry Data and Current Literature

End-stage ankle arthritis has a significant effect on function and quality of life. Total ankle arthroplasty continues to emerge as a safe and effective treatment of ankle arthritis. Ankle arthroplasty preserves motion at the ankle joint, while still achieving the primary goal of pain relief. With encouraging outcomes and improved implant longevity, there has been significant improvement on the results of first-generation implants. Further high-quality studies are required to clarify outcomes post ankle arthroplasty. This article reviews the latest data from national registries and the wider literature to evaluate the current status with outcomes of modern total ankle replacements.

Complications and results of the arthrodesis after total ankle arthroplasty failure: a retrospective monocentric study of 12 cases

INTRODUCTION

Total ankle arthroplasty (TAA) has the objective to maintain the range of motion of the tibiotarsal joint and to preserve the nearby joints. However, the complication rate and failures remain quite high after TAA. The main objective of the study was to evaluate the improvement in the functional scores of the tibiotarsal arthrodesis after TAA failure. The secondary objective was to assess the specific complications.

MATERIALS AND METHODS

This monocentric retrospective series includes 12 patients (nine men, three women, average age 52.5 years) operated between 2003 and 2018. An iliac graft was used in all cases. The arthrodesis was stabilized either by screws or by retrograde nailing.

RESULTS

The reoperation was due to painful malleolar conflicts or loosening. The AOFAS score increased from 38/100 to 67/100 (51-86) post-operatively. The fusion was acquired at 3.7 months (3-6) except in two cases.

DISCUSSION AND CONCLUSION

The 83% primary fusion rate is in the low average of the literature and 92% fusion rate in the high average after reoperation. All patients were improved even in two non-unions. The results of this study confirm that the arthrodesis after TAA failure is a reliable alternative to the TAA replacement. However, they are lower than those after a first-line arthrodesis.

Synovial Metallosis After Ceramic Total Ankle Arthroplasty Treated With a Total Talar Prosthesis: A Case Report

Total ankle arthroplasty is a useful surgical procedure for osteoarthritis of the ankle, but aseptic loosening of components is an issue. We report here a case of aseptic implant loosening with metallosis after total ankle arthroplasty using the TNK ankle (Kyocera, Kyoto, Japan), which occurred despite the components being ceramic. We also report favorable results from our method of treatment using a total talar prosthesis in the revision surgery. During the revision surgery, synovial metallosis was found, probably related to superficial damage to the screw affixing the tibial component to the bone. Because both the tibial and talar components were loose, all the components and the remaining talar bone were removed. A new tibial component and a custom-made alumina-ceramic total talar prosthesis was inserted. Pain relief was achieved and maintained through the latest follow-up visit at 42 months after revision surgery. Dorsiflexion of the ankle improved from 0° to 5° and plantarflexion remained unchanged from its preoperative range of 20°. The American Orthopaedic Foot & Ankle Society ankle-hindfoot score improved from 38 to 80 points. To the best of our knowledge, this is the first reported case of an alumina-ceramic total ankle prosthesis loosening caused by metallosis resulting from screw abrasion. Favorable treatment results were obtained by using a total talar prosthesis in the revision surgery.

What Is the Treatment "Algorithm" for an Infected Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

The treatment of an infected total ankle arthroplasty (TAA) is largely dictated by the acuity of the infection. The following treatment algorithm modified for TAA is recommended.¹⁹.

LEVEL OF EVIDENCE

Limited.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

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.

Outcomes of Acute Hematogenous Periprosthetic Joint Infection in Total Ankle Arthroplasty Treated With Irrigation, Debridement, and Polyethylene Exchange

BACKGROUND

Acute hematogenous periprosthetic joint infection (PJI) is defined in the literature as infection diagnosed and treated within 2 to 4 weeks from the onset of symptoms. In total hip and knee arthroplasty, irrigation and debridement (I&D) and polyethylene exchange with component retention has been studied extensively. However, there is minimal literature evaluating this treatment method for PJI in total ankle arthroplasty (TAA). The purpose of this study was to evaluate both the clinical and patient-reported outcomes and survivorship of TAA acute hematogenous PJIs treated with I&D and polyethylene exchange.

METHODS

A single-center, retrospective chart review of prospectively collected data in patients with TAA PJI who subsequently underwent I&D and polyethylene exchange with retention of metal components was conducted. The primary outcome was failure rate of I&D and polyethylene exchange, where failure was defined as subsequent removal of all components and 2-stage revision or arthrodesis. Patient-reported outcomes collected before primary arthroplasty, after primary arthroplasty, and after polyethylene exchange were also analyzed.

RESULTS

We identified 14 patients with acute hematogenous PJI who underwent I&D and polyethylene exchange with retention of metal components. The mean time from primary TAA to symptoms was 43 months (range 1-147 months). The average time from onset of symptoms to I&D and polyethylene exchange was 11.4 ± 5.6 days. The mean follow-up after this surgery was 2.8 ± 1.5 years. The long-term failure rate was 54%. The most common bacteria isolated in patients who failed was methicillin-resistant Staphylococcus aureus (MRSA). The most common bacteria isolated in patients who retained their implants was methicillin-sensitive Staphylococcus aureus (MSSA). Visual analog scale (VAS), Short Musculoskeletal Function Assessment (SMFA), Short Form-36 (SF-36), and American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot scale showed significant improvement when compared to preoperative scores in patients who retained their implants both after primary and after I&D and polyethylene exchange.

CONCLUSIONS

I&D and polyethylene exchange with retention of metal components has a long-term survivorship comparable to those reported in the total knee and total hip arthroplasty literature. Patient-reported outcomes after I&D and polyethylene exchange were comparable to those collected after primary arthroplasty in those patients who ultimately retained their implants. Two variables in this cohort that were associated with I&D and polyethylene exchange failure include time the patient was symptomatic prior to I&D as well as organism isolated on culture. With a failure rate of 54%, the authors recommend thorough evaluation on a case-by-case basis prior to indicating a patient for single-stage I&D with polyethylene exchange.

LEVELS OF EVIDENCE

Level IV, case series.

Evaluation of Midterm Results of the Panta Nail: An Active Compression Tibiotalocalcaneal Arthrodesis Device

A tibiotalocalcaneal intramedullary rod is a powerful construct often reserved for difficult and salvage cases. The Panta Nail (Integra LifeSciences, Plainsboro, NJ) is a second-generation rod that offers active axial compression compared with previous rod designs. We characterized our experience with this device and identified factors associated with nonunion. We retrospectively identified 19 patients receiving the Panta Nail during a 4-year period with a mean follow-up period of 16 months. We used a consecutive series approach toward inclusion. Fusion, asymptomatic fibrous union, or nonunion was determined for each ankle and subtalar joint as the primary endpoint. Patients were grouped as follows: group A, successful outcome; group B, successful outcome after dynamization; group C, no successful outcome. Secondary data were tested for association with the probability of first-attempt fusion. The Panta Nail resulted in a first-attempt fusion rate of 65% at the ankle and subtalar joints. With implementation of dynamization (31% of cases) at an average of 28 weeks after insertion (groups A and B), the bony fusion rate was 88% and 77% at the ankle and subtalar joint, respectively. Inclusion of 3 asymptomatic fibrous unions with final visual analog scale scores <4 (1 ankle; 2 subtalar) as successful outcomes resulted in 94% and 88% success rates for the ankle and subtalar joints (groups A and B). Salvaged total ankle arthroplasties with the Panta Nail device as a subgroup had an 83% fusion rate, with a 50% dynamization rate. No predictors of nonunion were found. The Panta Nail is a second-generation tibiotalocalcaneal arthrodesis device capable of providing good success rates for fusion. Also, dynamization is an appropriate and frequent augmentation method.

Revision of failed total ankle arthroplasty to a hindfoot fusion

Aims

The aim of this study was to present a series of patients with aseptic failure of a total ankle arthroplasty (TAA) who were treated with fusion of the hindfoot using a nail.

Patients and Methods

A total of 23 TAAs, in 22 patients, were revised for aseptic loosening and balloon osteolysis to a hindfoot fusion by a single surgeon (NH) between January 2012 and August 2014. The procedure was carried out without bone graft using the Phoenix, Biomet Hindfoot Arthrodesis Nail. Preoperative investigations included full blood count, CRP and ESR, and radiological investigations including plain radiographs and CT scans. Postoperative plain radiographs were assessed for fusion. When there was any doubt, CT scans were performed.

Results

The mean follow-up was 13.9 months (4.3 to 37.2). Union occurred at the tibiotalar joint in 22 ankles (95.6%) with one partial union. Union occurred at the subtalar joint in 20 ankles (87%) of cases with two nonunions. The nail broke in one patient with a subtalar nonunion and revision was undertaken. The only other noted complication was one patient who suffered a stress fracture at the proximal aspect of the nail, which was satisfactorily treated conservatively.

Conclusion

This study represents the largest group of patients reported to have undergone revision TAA to fusion of the hindfoot with good results Cite this article: Bone Joint J 2018;100-B:475–9.

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.

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.

How To Diagnose and Treat Infection in Total Ankle Arthroplasty

Periprosthetic infection after total ankle arthroplasty (TAA) is a serious complication, often requiring revision surgery, including revision arthroplasty, conversion to ankle arthrodesis, or even amputation. Risk factors for periprosthetic ankle infection include prior surgery at the site of infection, low functional preoperative score, diabetes, and wound healing problems. The clinical presentation of patients with periprosthetic ankle joint infection can be variable and dependent on infection manifestation: acute versus chronic. The initial evaluation in patients with suspected periprosthetic joint infections should include blood tests: C-reactive protein and erythrocyte sedimentation rate. Joint aspiration and synovial fluid analysis can help confirm suspected periprosthetic ankle infection.

[Aseptic loosening of total ankle replacement and conversion to ankle arthrodesis]

OBJECTIVE

To remove loosened prosthesis components, to perform augmentation, to address osseous defects, to perform neutrally aligned ankle arthrodesis, and to achieve postoperative pain relief.

INDICATIONS

Symptomatic, aseptic loosening of total ankle replacement (TAR) with/without substantial bone defect of the tibial and/or talar bone stock.

CONTRAINDICATIONS

General surgical or anesthesiological risks, periprosthetic infection, local or systemic infection, nonmanageable soft tissue problems.

SURGICAL TECHNIQUE

Removal of both prosthesis components using the previous incision (mostly using anterior ankle approach). Careful debridement of bone stock at the tibial and talar side. Osseous augmentation of defects using autologous or homologous cancellous bone, if needed, using structural allografts.

POSTOPERATIVE MANAGEMENT

A soft wound dressing is used. Thromboprophylaxis is recommended. Patient mobilization starts on postoperative day 1 with 15 kg partial weight bearing using a stabilizing walking boot or cast for 6-8 weeks. Following clinical and radiographic follow-up at 6 weeks, full weight bearing is initiated gradually after progressive osseous healing has been confirmed.

RESULTS

Between January 2007 and December 2012, ankle arthrodesis was performed in 9 patients with failed TAR (6 men and 3 women, mean age 56.4 ± 7.0 years, range 47.8-66.0 years). The mean time between the initial TAR and revision surgery was 4.5 ± 2.4 years (range 1.2-7.9 years). In one patient irrigation and debridement was performed due to superficial wound infection. Another patient had a delayed osseous healing 11 months after the revision surgery.

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.

Hindfoot Arthrodesis with the Blade Plate: Increased Risk of Complications and Nonunion in a Complex Patient Population

BACKGROUND

Previous hindfoot surgeries present a unique challenge to hindfoot arthrodesis, as the patients may have multiple incisions around the hindfoot. In high-risk patients with compromised soft tissues, a posterior approach can provide an alternative for a fresh soft tissue plane for the surgery. The use of a blade plate construct is widely accepted; however, there are limited data supporting the use of a posterior approach.

QUESTIONS/PURPOSES

We asked (1) what proportion of patients treated with this technique achieved osseous union; (2) what complications were observed; (3) were any patient-demographic or health-related factors associated with the likelihood that a patient would have a complication develop?

METHODS

Between December 2001 and July 2014, 42 patients received a posterior blade plate. During the period in question, indications for hindfoot arthrodesis using posterior blade fixation were subtalar osteoarthritis below an ankle fusion, malunion or nonunion, failed tibiotalocalcaneal arthrodesis attributable to nonunion of the tibiotalar and/or subtalar joint; or tibiotalar and subtalar osteoarthritis in patients with impaired bone or soft tissue quality (particularly if the soft tissue problem was anterior). During that period, all patients who met those indications were treated with a posterior blade plate. Forty (95%) were included in this study, and two were lost to followup before the 1-year minimum required by the study. Demographics (age, gender, BMI, smoking status, and comorbidities) and surgical data (indication, previous treatment, and additional procedures) were analyzed. Of the 40 patients included, 27 (68%) were male and 13 (33%) were female, with a median of two previous hindfoot or ankle surgeries (range, 0-9 surgeries). The mean age of the patients was 56 ± 13 years. Followup averaged 47 ± 28 months (range, 14-137 months). Twenty-eight of 40 (70%) patients had a tibiotalocalcaneal arthrodesis as a primary (n = 6), primary staged (n = 10), revision (n = 9), or revision staged (n = 3) procedure. Eleven of 40 patients (28%) underwent ankle arthrodesis (primary n = 7, revision n = 4). One of the 40 patients (3%) underwent tibiotalocalcaneal arthrodesis for a failed total ankle arthroplasty. Weightbearing radiographs were used to assess fusion. Osseous fusion was defined as visible trabecular bridging on the lateral and AP ankle views within 6 postoperative months. Delayed union was defined as osseous fusion occurring between 6 and 12 months. Nonunion was defined as no visible trabecular bridging at the latest followup (longer than 12 months). Clinic and surgery notes were reviewed for complications. Univariate analysis was performed to compare patient groups: patients with solid union versus nonunion, and patients with versus without complications.

RESULTS

Twenty-nine of 40 (73%) patients had osseous fusion within 6 postoperative months. Four of 40 (10%) patients had a delayed union between 6 and 12 months, and seven of the 40 (18%) patients had nonunions, which occurred in the ankle (n = 3), subtalar (n = 3), or both (n = 1) joints. There were 26 complications observed: 18 (69%) were considered major and eight (31%) were minor. With the numbers available, we did not identify any demographic or surgical factors associated with complications, delayed union, or nonunion.

CONCLUSIONS

The proportion of patients treated with a posterior blade plate hindfoot fusion who had delayed union or nonunion is greater than that reported for patients in other series who underwent primary hindfoot arthrodesis with other approaches, and the proportion of patients who had complications develop is high. Further studies are needed to address alternative approaches to achieve hindfoot fusion in patients with complex hindfoot problems.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Total Ankle Arthroplasty: An Imaging Overview

With advances in implant technology, total ankle arthroplasty (TAA) has become an increasingly popular alternative to arthrodesis for the management of end-stage ankle arthritis. However, reports in the literature do not focus on the imaging features of TAA. Through a literature review, we demonstrate basic design features of the current ankle arthroplasty system, and the normal and abnormal postoperative imaging features associated with such devices. Pre- and postoperative evaluations of ankle arthroplasty mainly include radiography; in addition, computed tomography and magnetic resonance imaging provide further characterization of imaging abnormalities. Familiarization with multimodal imaging features of frequent procedural complications at various postoperative intervals is important in radiological practice.

Outcome After Salvage Arthrodesis for Failed Total Ankle Replacement

BACKGROUND

In cases with total ankle replacement (TAR) failure, a decision between revision TAR and salvage arthrodesis (SA) must be made. In a previous study, we analyzed revision TAR and found low functional outcome and satisfaction. The aims of the current study were to analyze SA concerning failure rate and patient-related outcome measures (PROMs).

METHODS

Until September 2014, a total of 1110 primary TARs were recorded in the Swedish Ankle Registry. Of the 188 failures, 118 were revised with SA (and 70 with revision TAR). Patient- and implant-specific data for SA cases were analyzed as well as arthrodesis techniques. Failure of SA was defined as repeat arthrodesis or amputation. Generic and region-specific PROMs of 68 patients alive with a solid unilateral SA performed more than 1 year before were analyzed.

RESULTS

The first-attempt solid arthrodesis rate of SA was 90%. Overall, 25 of 53 (47%) patients were very satisfied or satisfied. Mean Self-reported Foot and Ankle Score (SEFAS) was 22 (95% confidence interval 20-24), Euro Qol-5 Dimensions 0.57 (0.49-0.65), Euro Qol-Visual Analogue Scale 59 (53-64), Short Form-36 physical 34 (31-37) and mental 50 (46-54). The scores and satisfaction were similar to those after revision TAR but the reoperation rate was significantly lower in SA (P < .05).

CONCLUSION

Salvage arthrodesis after failed TAR had a solid arthrodesis rate of 90% at first attempt, but similar to revision TAR, less than 50% of the patients were satisfied and the functional scores were low. Until studies show true benefit of revision TAR over SA, we favor SA for failed TAR.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

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.

Poor prosthesis survival and function after component exchange of total ankle prostheses

BACKGROUND AND PURPOSE

In failed total ankle replacements (TARs), fusion is often the procedure of preference; the outcome after exchanging prosthetic components is debated. We analyzed prosthetic survival, self-reported function, and patient satisfaction after component exchange. Patients and methods We identified patients in the Swedish Ankle Registry who underwent exchange of a tibial and/or talar component between January 1, 1993 and July 1, 2013 and estimated prosthetic survival by Kaplan-Meier analysis. We evaluated the patient-reported outcome measures (PROMs) SEFAS, EQ-5D, EQ-VAS, SF-36, and patient satisfaction by direct questions.

RESULTS

69 patients underwent revision TAR median 22 (0-110) months after the primary procedure. 24 of these failed again after median 26 (1-110) months. Survival analysis of revision TAR showed a 5-year survival rate of 76% and a 10-year survival of 55%. 29 patients with first revision TAR in situ answered the PROMs at mean 8 (1-17) years after revision and had the following mean scores: SEFAS 22, SF-36 physical 37 and mental 49, EQ-5D index 0.6, and EQ-VAS 64. 15 of the patients were satisfied, 5 were neither satisfied nor dissatisfied, and 9 were dissatisfied.

INTERPRETATION

Revision TAR had a 10-year survival of 55%, which is lower than the 10-year survival of 74% for primary TAR reported from the same registry. Only half of the patients were satisfied. Future studies should show which, if any, patients benefit from revision TAR and which patients should rather be fused directly.