Prospective study of a cementless, mobile-bearing, third generation total ankle prosthesis

Current concepts in ankle arthrodesis

Ankle osteoarthritis is primarily post traumatic and affects a younger population. It, therefore, not only has a negative effect on the quality of life but also impacts the working life of these patients. A thorough history, clinical examination followed by relevant investigations, radiological and hematological, can provide the necessary information to classify the severity and associated deformity of this condition. This will provide guidance to the necessary and appropriate commencement of treatment. Options include conservative or surgical which can be joint sparing or sacrificing procedures. Ankle arthrodesis, a joint sacrificing procedure, has long been the 'gold standard' and has stood the test of time in providing a pain free plantigrade foot. However, ankle arthroplasty, with newer materials and better understanding, is increasingly being considered for ankle arthritis. In regions with financial constraints and limited accessibility to modern implants ankle arthrodesis should be the preferentially offered surgical procedure. This article will briefly cover the pathophysiology of ankle arthritis, clinical presentation, and its surgical treatment with a focus on ankle arthrodesis.

Outcomes of Total Ankle Arthroplasty After Periprosthetic Cyst Curettage and Bone Grafting

Total ankle arthroplasty (TAA) has become a popular management option for ankle arthritis. Periprosthetic osteolysis is one of the most common causes for reoperation in TAA. A CT scan should be done in all suspected osteolysis cases to confirm location, quantify size and aid in surgical planning. These patients are often asymptomatic with limited evidence regarding appropriate management. Smaller lesions should be monitored for progression in size. Periprosthetic cysts measuring 10-15mm in all three axes should be considered for debridment and curettage with autogenous bone grafting. The authors believe that bone grafting of large asymptomatic periprosthetic cysts could prevent implant failure.

Computed Tomography Derived Patient-specific Instrumentation Total Ankle Arthroplasty Survivorship Outcomes

Computed tomography (CT) derived patient-specific total ankle arthroplasty (TAA) systems have been utilized for improved accuracy and reproducible implant alignment. The purpose of the present study was to report the overall implant survivorship as well as radiographic analysis of patients who underwent primary TAA utilizing CT-derived patient-specific instrumentation. A retrospective review of medical charts and radiographs were performed on patients who had undergone primary TAA at a single institution in the Midwest region from March 2013 to October 2020. Radiographic analysis included preoperative, initial postoperative, and final follow-up coronal and sagittal tibiotalar alignment as well as periprosthetic radiolucency. A total of 96 patients with a mean follow-up of 3 years (range, 0.3-7.3 years) were included. Implant survivorship was found to be 92% at median follow-up of 3 years. A total of 8 cases (8.3%) required revision/reoperation, with 6 (6.3%) of these reoperations directly related for failure of one of the metallic implant components. There was significant improvement in both coronal and sagittal tibiotalar alignment from preoperative to initial postoperative follow-up (p < .001). At latest postoperative follow-up, there were 88% of TAAs that remained in a neutral alignment following surgery. A total of 10 cases were found to have radiolucency at latest follow-up. In conclusion, the use of CT derived patient-specific TAA showed high implant survivorship with significant improvement of sagittal and coronal tibiotalar alignment. With better implant alignment and position, it potentially reduces the risk of early implant failure or implant loosening in long-term follow-up.

Fast-Track for Total Ankle Replacement: A Novel Enhanced Recovery Protocol for Select Patients

BACKGROUND

Enhanced recovery after surgery programs, also called fast-track protocols, were developed and successfully applied in the last decade for hip and knee reconstruction. Specific fast-track protocols have not yet been applied to ankle prostheses. The aim of the study was to develop and validate an enhanced recovery protocol for total ankle replacement (TAR) evaluating the clinical and radiographic results. We hypothesize that on the basis of well-defined pre- and postoperative characteristics, the current knowledge on ankle replacement, and referring to hip and knee reconstruction, it is possible to identify a "patient type" to be safely eligible to a Fast-Track Protocol with at least comparable results and without increasing the complications risk.

METHODS

We identified 8 predictive variables that might affect the outcome of TAR. Those variables were the body mass index, the state of anxiety or depression, the functional preoperative status, ankle equinus, the coronal malalignment, the surgical time, the surgical accessory procedures, and the bone quality. These characteristics were evaluated for each patient with almost validated outcome tools attributing a specific score. Based on the score obtained, the patients were divided into 2 groups: the Standard Protocol group (Control Group) and the Fast-Track Protocol group (Study Group). The main difference between treatment of the 2 groups relates to the use of postoperative plaster casts: in the Fast-Track group the cast was removed the first day after surgery and walking was allowed in sports shoes assisted with crutches, whereas in the Standard Protocol group, the cast was removed after 3 weeks. Clinical and radiographic evaluation was performed for all patients preoperatively and postoperatively every 6 months.

RESULTS

A total of 163 patients received a score between 1 and 5 and were included in the control group (Standard Protocol); 47 patients received a score of 0 and were allocated to the study group (Fast-Track Protocol). Clinically, except for the preoperative American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale score, no statistically significant differences were recorded in the multiple comparisons between the 2 groups. No significant differences were found regarding complications.

CONCLUSION

In selected patients, it is possible to apply an enhanced recovery protocol of rehabilitation, focused on immediate weightbearing and mobilization without any plaster or boot.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Intermediate to long-term clinical outcomes and survival analysis of the Salto Mobile Bearing total ankle prothesis

INTRODUCTION

Osteoarthritis of the ankle is a major burden to affected patients. While tibio-talar arthrodesis has been the gold-standard regarding the treatment of osteoarthritis of the ankle joint for many years, at present total ankle arthroplasty (TAA) provides appealing clinical outcomes and is continually gaining popularity. The aim of this study was to evaluate the intermediate- to long-term clinical outcome including the survival rate of Salto Mobile Bearing TAA (Tonier SA, Saint Ismier, France).

MATERIAL AND METHODS

In this retrospective study intermediate- to long-term outcomes measures [Ankle Range of Motion (ROM), American Orthopaedic Foot and Ankle Score (AOFAS score) and survival rate] of 171 consecutive TAA were analysed and compared before and after surgery. Revision was defined as secondary surgery with prothesis component removal, while reoperation was defined as a non-revisional secondary surgery involving the ankle.

RESULTS

At a mean follow-up (FU) period of 7.2 ± 2.7 years (range 2.0 to 14.1 years) there was a significant improvement in ankle ROM (total ROM improved from 25.0° ± 15.0° to 28.7° ± 11.3°, p = 0.015; plantarflexion improved from 18.4° ± 11.7° to 20.6° ± 8.2°, p = 0.044; dorsiflexion improved from 6.6° ± 5.7° to 8.1° ± 4.9°, p = 0.011). AOFAS score increased significantly by 41 ± 15 points after surgery (43.3 ± 11.1 before and 84.3 ± 12.0 after surgery, p < 0.001). Overall survival rate within the FU was 81.3% (95% CI 75.3% to 87.3%) with any secondary surgery, 89.9% (95% CI 84.1% to 93.6%) with revision and 93.6% (95% CI 89.8% to 97.3%) with reoperation as endpoint.

CONCLUSION

This study endorses the previously reported appealing intermediate- to long-term outcomes of the Salto Mobile Bearing TAA. There was a significant increase in ROM and AOFAS score as well as decent implant survival at final FU.

Long-term Follow-up of 254 Ceramic Coated Implant (CCI) Evolution Total Ankle Replacements

BACKGROUND

The ceramic coated implant (CCI) Evolution was a third-generation implant design used in approximately 2000 total ankle replacements (TARs) between 2003 and 2016. Because this implant was abandoned, long-term follow-up studies are lacking.

METHODS

All patients undergoing TAR using a CCI prosthesis between 2004 and 2012 were included for analysis. Preoperatively the tibiotalar alignment was measured, and postoperatively the patients were followed up clinically, with radiographs and by questionnaire. The primary outcome was implant survival at 10 years of follow-up. Implant survival was also compared for (1) inflammatory joint disease vs noninflammatory joint disease and (2) preoperative tibiotalar neutral vs varus or valgus alignment. The secondary outcomes were complications, reoperations, and function (assessed by patient-reported outcome measures).

RESULTS

Two hundred fifty-four TARs were performed in 237 patients. Two hundred twelve additional procedures were performed to achieve stable ankles. At 10-year follow-up, the survival was 67.5%, with an average time to revision of 4.5 years. The 10-year survival of the inflammatory joint disease group was 76.8% and of the noninflammatory joint group 63.1% (P = .44). In 248 TARs, the preoperative tibiotalar alignment was measured; (62% neutral, 25% varus, and 13% valgus), these showed 10-year survival rates of 74.7%, 48.2%, and 68.9% respectively (P = .07). The complication rate was 54%; 37% of patients underwent reoperation. At a mean of 8.5 years, postoperative satisfaction scored an average of 7.0 (SD 2.26) on a 0- to 10-point numeric rating scale. The mean Foot and Ankle Ability Measure sports subscore was 24.7, the mean Foot and Ankle Outcome Score (FAOS) sports subscore was 42.8, and the mean 36-Item Short Form Health Survey score was 40.0. Regarding daily activities, the mean FAOS was 81.0.

CONCLUSION

This is currently the sole study reporting the long-term results of the CCI prosthesis. The survival and functional outcomes were inferior to other third-generation mobile-bearing ankle implants.

Ten-year revision rates of contemporary total ankle arthroplasties equal 22%. A meta-analysis

BACKGROUND

The National Institute for Health and Care Excellence criterion for hip replacements is a (projected) revision rate of less than 5% after 10 years. No such criterion is available for ankle prostheses. The objective of the current study is to compare survival rates of contemporary primary ankle prostheses to the hip-benchmark.

METHODS

The PRISMA methodology was used. Eligible for inclusion were clinical studies reporting revision rates of currently available primary total ankle prostheses. Data was extracted using preconstructed forms. The total and prosthesis-specific annual revision rate was calculated.

RESULTS

Fifty-seven articles of eight different ankle prostheses were included (n = 5371), totaling 513 revisions at an average 4.6 years of follow-up. An annual revision rate of 2.2 was found (i.e. an expected revision rate of 22% at 10 years).

CONCLUSIONS

The expected 10-year revision rate of contemporary ankle prostheses is lower than the current benchmark for hip prostheses.

Effects of Patient-Specific Instrumentation and Ancillary Surgery Performed in Conjunction With Total Ankle Implant Arthroplasty: Postoperative Radiographic Findings

Accuracy and reproducibility when performing total ankle implant arthroplasty (TAA) are essential for longevity of the implant, maintaining relative stability of the joint, and theoretically reducing the formation of adjacent joint arthritis in the subtalar and knee joints. Studies have helped to illustrate the accuracy of implantation when using patient-specific instrumentation in both knee and ankle implant arthroplasty. Despite the findings of these studies, few have gone on to evaluate the effects of ancillary procedures on TAA; particularly their effects on postoperative implant congruity when performed simultaneously with joint replacement surgery. In this study, preoperative plans on implant alignment based on patient-specific computed tomography images were compared with the alignment observed on immediate postoperative radiographs. Additionally, postoperative joint congruity was measured, and operative reports were assessed to determine if concomitant procedures performed with total ankle replacement had a significant effect on overall alignment. In our population, 46/47 implants were within 1.5° of their anticipated placement in the coronal plane, and 100% were within 2° of anticipated placement in the sagittal plane. Using a spearman's rank-order correlation, our data failed to show any significant relationship between conducting additional procedures in conjunction with TAA (rho = 0.178; p value = .232) and postoperative congruency of the implant. These findings help support the accuracy of ankle implantation using patient-specific instrumentation, while also supporting the appropriate use of indicated procedures in conjunction with total ankle replacement to help obtain a congruent joint postoperatively.

CT Scan Assessment and Functional Outcome of Periprosthetic Bone Grafting After Total Ankle Arthroplasty at Medium-term Follow-up

BACKGROUND

Periprosthetic cysts can occur in up to 95% of total ankle arthroplasties (TAA) and have been correlated with implant failure. The aim of this study was to determine the clinical and radiologic outcomes, using computed tomographic (CT) scan, after periprosthetic cyst bone grafting and assess for the minimum cyst size that should be grafted.

METHODS

A retrospective review was performed of all TAA procedures performed between 2007 and 2014 (n=93). A CT scan was done to assess cyst size and operative planning. Eight patients with 9 periprosthetic cysts larger than 1.75 cm³ were grafted and specimens sent for histology. The mean time to bone grafting was 7.3 (3.8-9.5) years. Functional outcome was assessed using the American Orthopaedic Foot & Ankle Society ankle score, visual analog scale, and Self-reported Foot and Ankle Score. A CT scan was performed at follow-up to assess graft incorporation and cyst size progression. The mean time to CT scan post grafting was 3.0 (0.7-4.7) years.

RESULTS

There was no implant malalignment identified and no differences in the pre- and postoperative functional scores. Preoperatively cysts had a mean volume of 8.16 (2.04-14.03) cm³. The mean percentage incorporation was 89% (69%-100%). Eight of the grafted cysts were considered successful on CT, with the ninth having 69% incorporation. Five cysts were not grafted, as they were below 1.75 cm³, and remained the same size or had minimal enlargement.

CONCLUSION

The satisfactory results in this small cohort suggests that prophylactic bone grafting may extend implant survival. We recommend that periprosthetic cysts greater than 1.75 cm³ be prophylactically bone grafted, and that cysts smaller than 1.75 cm³ be monitored for progression in size.

LEVEL OF EVIDENCE

Level IV, Case Series.

Transfibular total ankle arthroplasty : a new reliable procedure at five-year follow-up

AIMS

This study reports updates the previously published two-year clinical, functional, and radiological results of a group of patients who underwent transfibular total ankle arthroplasty (TAA), with follow-up extended to a minimum of five years.

METHODS

We prospectively evaluated 89 patients who underwent transfibular TAA for end-stage osteoarthritis. Patients' clinical and radiological examinations were collected pre- and postoperatively at six months and then annually for up to five years of follow-up. Three patients were lost at the final follow-up with a total of 86 patients at the final follow-up.

RESULTS

A total of 86 patients were evaluated at a mean follow-up of 65.4 months (60 to 90). At five-year follow-up, statistically significant improvements (p < 0.001) were found in the mean American Orthopaedic Foot & Ankle Society Ankle Hindfoot Score (from 33.8 (SD 14.3) to 86.1 (SD 8.8)), visual analogue scale for pain (from 8.5 (SD 1.7) to 1.5 (SD 1.2)), Short Form-12 Physical and Mental Component Scores (from 29.9 (SD 6.7) and 43.3 (SD 8.6) to 47.3 (SD 7.5) and 52.2 (SD 8.0), respectively), and mean ankle dorsiflexion and plantarflexion (from 6.2° (SD 5.5°) and 9.6° (SD 5.8°) to 23.9° (SD 7.7°) and 16.9° (SD 7.2°), respectively). Radiologically, the implants maintained neutral alignment without subsidence. Tibial or talar radiolucency was found in eight patients, but none of these patients was symptomatic. At five-year follow up, 97.7% of implants (95% confidence interval 91.2 to 99.4) were free from revision or removal with 84 implants at risk. We recorded two cases (2.3%) of failure for septic loosening.

CONCLUSION

Transfibular TAA is safe and effective with a high survival rate at mid-term follow-up and satisfactory clinical and radiological results. Further studies are required to determine the long-term performance of these implants. Cite this article: Bone Joint J 2022;104-B(4):472-478.

Three-Year Rates of Reoperation and Revision Following Mobile Versus Fixed-Bearing Total Ankle Arthroplasty: A Cohort of 302 Patients with 2 Implants of Similar Design

BACKGROUND

Currently, the implants utilized in total ankle arthroplasty (TAA) are divided between mobile-bearing 3-component and fixed-bearing 2-component designs. The literature evaluating the influence of this mobility difference on implant survival is sparse. The purpose of the present study was therefore to compare the short-term survival of 2 implants of similar design from the same manufacturer, surgically implanted by the same surgeons, in fixed-bearing or mobile-bearing versions.

METHODS

All patients were enrolled who underwent TAA with either the mobile-bearing Salto (Tornier and Integra) or the fixed-bearing Salto Talaris (Integra) in 3 centers by 2 surgeons between January 2004 and March 2018. All patients who underwent TAA from January 2004 to April 2013 received the Salto implant, and all patients who underwent TAA after November 2012 received the Salto Talaris implant. The primary outcome was time, within 3 years, to first all-cause reoperation, revision of any metal component, and revision of any component, including the polyethylene insert. Secondary outcomes included the frequency, cause, and type of reoperation.

RESULTS

A total of 302 consecutive patients were included, of whom 171 received the mobile-bearing and 131 received the fixed-bearing implant. The adjusted hazard ratio for all-cause reoperation was 1.42 (95% confidence interval [CI], 0.67 to 3.00; p = 0.36); for component revision, 3.31 (95% CI, 0.93 to 11.79; p = 0.06); and for metal component revision, 2.78 (95% CI, 0.58 to 13.33; p = 0.20). A total of 31 reoperations were performed in the mobile-bearing group compared with 14 in the fixed-bearing group (p = 0.07). More extensive reoperation procedures were performed in the mobile-bearing group.

CONCLUSIONS

With the largest comparison of 2 implants of similar design from the same manufacturer, the present study supports the use of a fixed-bearing design in terms of short-term failure. We found a 3-times higher rate of revision among mobile-bearing implants compared with fixed-bearing implants at 3 years after TAA. Reoperations, including first and subsequent procedures, tended to be less common and the causes and types of reoperations less extensive among fixed-bearing implants.

LEVEL OF EVIDENCE

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

Anterior placement of the talar component in total ankle arthroplasty: A risk factor for talar component subsidence

BACKGROUND

Component subsidence is considered as a cause of revision surgery. The talar component subsidence may be a risk factor for revision surgery; however, there are no reports regarding talar component placement and subsidence amount following total ankle arthroplasty (TAA). We therefore investigated the relationship between talar component placement and subsidence amount.

METHODS

Fifty-two ankles from 49 patients (age: 71 years [range 62-83], 13 male/ 36 female), who underwent TAA with mean follow-up of 36 months (range 12-83), were included. The subjects were divided into two groups based on talar component placement: anterior placement (n = 20, group A) and posterior placement (n = 32, group P) using weight-bearing lateral plain radiographs. The amount of the talar component subsidence and clinical outcomes, which included the Japanese Society for Surgery of the Foot (JSSF) scale, range of the motion (ROM) and the revision rate, were compared between the groups.

RESULTS

Talar component subsidence was significantly higher in group A (2.1 ± 2.0 mm) than in group P (0.6 ± 1.4 mm, P = .017). There was no significant difference in the JSSF scale and ROM between group A and group P. The revision rate was 10.0% in group A and 6.3% in group P, albeit not statistically significant.

CONCLUSION

Greater talar component subsidence was observed when the talar component was placed more anteriorly, suggesting that anterior placement of the talar component may need to be avoided during the surgery in order to minimize the postoperative talar component subsidence.

Modern total ankle arthroplasty versus ankle arthrodesis: A systematic review and meta-analysis

The controversy in surgical management of end-stage tibiotalar arthritis with Total Ankle Arthroplasty (TAA) versus Ankle Arthrodesis (AA) has grown in parallel with the evolution of both procedures. No randomized controlled trials exist due to the vast differences in surgical goals, patient expectations, and complication profiles between the two procedures. This makes high quality systematic reviews necessary to compare outcomes between these two treatment options. The aim of this study was to provide a systematic review with meta-analysis of publications reporting outcomes, complications, and revision data following third-generation TAA and/or modern AA published in the past decade. Thirtyfive articles met eligibility criteria, which included 4312 TAA and 1091 AA procedures. This review reports data from a mean follow-up of 4.9 years in the TAA cohort and 4.0 years in the AA cohort. There was no significant difference in overall complication rate following TAA compared to AA (23.6% and 25.7% respectively, P-value 0.31). Similarly, there was no significant difference in revision rate following TAA compared to AA (7.2% and 6.3% respectively, P-value 0.65). Successful treatment of end-stage tibiotalar arthritis requires an understanding of a patients’ goals and expectations, coupled with appropriate patient selection for the chosen procedure. The decision to proceed with TAA or AA should be made on a case-by-case basis following an informed discussion with the patient regarding the different goals and complication profiles for each procedure.

Mid-Term Prospective Clinical and Radiographic Outcomes of a Modern Fixed-Bearing Total Ankle Arthroplasty

The early outcomes of the Salto Talaris® Total Ankle Prosthesis have been promising, but information on its mid-term outcomes is still sparse. The purpose of this study was to evaluate the mid-term clinical and radiographic outcomes of this implant among a prospective cohort of patients who underwent total ankle replacement for various etiologies. Forty-six patients (50 ankles) were consecutively enrolled in the study. Our primary aim was to assess implant survivorship as determined by the removal or revision of the implant metal components or conversion to arthrodesis. Our secondary aim was to gauge patient outcomes by using commonly used outcome scores and assess ankle range of motion using goniometric and radiographic methods. We report 100% survivorship of the implant at a mean follow-up of 4.9 years. Compared with preoperative levels, all clinical outcome scores showed significant improvement at the 1-year, 2-year, and 5-year and longer follow-up. The mean clinical ROM improved from 27.7° ± 10.7° preoperatively to 40.0° ± 12.3° at the 2-year follow-up (p < .001). The mean radiographic ROM improved from 23.0° ± 10.2° preoperatively to 27.2° ± 9.1° at the 2-year follow-up (p = .007). Reoperations or secondary procedures were performed on 6 (12%) ankles, with the most common procedure being gutter debridement for impingement symptoms. The study confirms that the excellent survivorship seen with the implant in the early studies extends to mid-term follow-up as well. Patients could expect to see improvement in pain relief and activity well into 5 years after surgery and retain sufficient ankle range of motion for normal gait.

Total ankle arthroplasty and ankle arthrodesis affect the biomechanics of the inner foot differently

Ankle arthrodesis and total ankle arthroplasty are the two primary surgeries for treatment of end-stage degenerative ankle arthritis. The biomechanical effects of them on the inner foot are insufficient to identify which is superior. This study compared biomechanical parameters among a foot treated by ankle arthrodesis, a foot treated by total ankle arthroplasty, and an intact foot using computational analysis. Validated finite element models of the three feet were developed and used to simulate the stance phase of gait. The results showed total ankle arthroplasty provides a more stable plantar pressure distribution than ankle arthrodesis. The highest contact pressure, 3.17 MPa, occurred in the medial cuneonavicular joint in the total ankle arthroplasty foot. Neither of the surgeries resulted in contact pressure increase in the subtalar joint. The peak stress in the metatarsal bones was increased in both surgical models, especially the second and third metatarsals. This study enables us to get visual to the biomechanics inside of an intact foot, and feet treated by total ankle arthroplasty and ankle arthrodesis during walking.

The Salto total ankle arthroplasty - Clinical and radiological outcomes at five years

BACKGROUND

Modern designs of total ankle arthroplasty (TAA) have the potential to treat symptomatic ankle OA without adversely affecting ankle biomechanics. We present the mid-term results of a modern, mobile-bearing TAA design.

METHODS

TAA was performed in 50 consecutive patients (55 ankles) in an independent, prospective, single-centre series. Implant survival, patient-reported outcome measures (PROMs) and radiographic outcomes are presented at a mean of five years (range 2-10.5years).

RESULTS

A total of three patients (four ankles) died and two (two ankles) were lost to follow-up. Three TAAs were revised for aseptic loosening (in two cases) or infection. Two further patients underwent reoperations, one for arthroscopic debridement of anterolateral synovitis and one for grafting of an asymptomatic tibial cyst. With all-cause revision as an endpoint, implant survival was 93.3% at five to ten years (95% CI 80.5%-97.8%). If reoperations are included this falls to 90.2% (95% CI 75.6%-96.3%) at five years. No other patient demonstrated radiographic evidence of loosening or subsidence. PROMs and satisfaction were excellent at latest follow-up.

CONCLUSION

At five years, the outcomes for this design of TAA in this series were excellent, and were similar to those of previously published series from the designer centre.

Long-term Follow-up Results of Buechel-Pappas Ankle Arthroplasty

BACKGROUND

Total ankle replacement (TAR) is gaining popularity as a treatment option for ankle osteoarthritis. Long-term implant survival is a critical outcome to determine the success of the TAR implant. The Buechel-Pappas (BP) implant is a second-generation mobile bearing implant. The aim of this study was to analyze the BP implant survivorship at 10-year follow-up, make a subanalysis between patient groups, and evaluate long-term functional outcomes.

METHODS

Data of 86 patients who received 101 BP implants between 1993 and 2010 were obtained from a prospectively documented database. Subanalyses were done for patients diagnosed with inflammatory joint disease and noninflammatory joint disease, and patients with preoperative tibiotalar neutral and nonneutral alignment. A Kaplan-Meier curve was used for survival analysis. Long-term functional outcomes were assessed with the following patient-reported outcome measures: Foot and Ankle Outcome Score (FAOS), Foot and Ankle Ability Measure (FAAM), Short Form-36 (SF-36) Stand Version 2.0 Health Survey and 3 anchor questions.

RESULTS

The survival rate of the BP implant at 10 years was 86% (95% confidence interval, 78%-93%). A total of 31 patients (36%) required 55 reoperations, and in 13 patients (15%) a revision procedure was performed. In this series, no significant difference in 10-year survival rate was found between neither the inflammatory joint disease and noninflammatory joint disease group ( P = .47), nor the tibiotalar neutral and nonneutral alignment group ( P = .16). At a mean follow-up of 16.8 years for 21 patients, the mean FAOS activities of daily living (ADL) and FAAM ADL subscale scores were 75/100 and 56/100 points. The mean physical component summary (PCS) and mental component summary (MCS) of the SF-36 were 34/100 and 51/100 points, respectively.

CONCLUSION

A survival rate of 86% was found at 10-year follow-up for the Buechel-Pappas implant. Our series demonstrated no significant difference in 10-year survival rates between the 2 patient subgroups. Long-term results of the various functional outcomes varied between poor and moderate.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Outcome after 52 Salto Ankle Prostheses Implanted by a Single Surgeon

While ankle arthrodesis was traditionally the gold standard method of treatment for disabling end-stage ankle arthritis, total ankle replacement (TAR) has been an acceptable alternative. The satisfaction rate of patients with TAR however differs. The purpose of our study is to investigate whether implant survival and results with special emphasis on the satisfaction rate of patients treated with a TAR implanted by a single surgeon were comparable to the literature. This was a retrospective cohort study in a teaching hospital. Data was collected from 52 patients who received a total ankle replacement (TAR) between 05/2002 and 06/2014. The mean follow-up time was 4.2 years (95% CI 3.3 - 5.0). Results showed a high satisfaction rate of 94% and 94% survival of the TAR after 5 years. We conclude that TAR with the Salto prosthesis is, in our hands, a reliable solution for end-stage ankle arthritis, with results comparable to the literature.

Short-term Clinical and Radiographic Results of the Salto Mobile Total Ankle Prosthesis

BACKGROUND

The mobile-bearing Salto total ankle prosthesis has been reported to have promising outcomes. However, clinical reports on this prosthesis are few, and most have been published by the inventors and disclosed consultants.

METHODS

We retrospectively reviewed 59 patients who received Salto prosthesis unilaterally. The average follow-up was 35.9 (range, 6-56) months. Clinical and radiologic results were evaluated. Clinical results were evaluated according to visual analog scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, Ankle Osteoarthritis Scale (AOS) pain and disability score, and ankle range of motion (ROM) in dorsiflexion/plantarflexion. In the radiographic evaluation, we measured the tibial angle (TA), talar angle (TAL), tibial slope, and talocalcaneal angle (TCA) on weightbearing radiographs.

RESULTS

By the last follow-up, 7 of 59 patients (11.9%) had undergone reoperation, and 3 of 59 implants (5.1%) had been removed. The prosthesis survival was 94.9% (95% CI, 89.1%-100%). With any reoperation as the endpoint of follow-up, the clinical success rate was 88.1% (95% CI, 79.4%-96.9%). The mean postoperative visual analog scale score, AOFAS ankle-hindfoot score, and Ankle Osteoarthritis Scale pain and disability score improved significantly ( P < .001). The ankle range of motion also improved from preoperative 33.4 ± 16.6 to 40.3 ± 15.5 postoperatively ( P < .001); however, there was no statistically significant change in plantarflexion ( P = .243). Radiolucent areas and osteolysis were found in 28 (47.5%) and 27 (45.8%) patients, respectively. Heterotopic ossification was observed in 13 patients (22.0%).

CONCLUSIONS

In this series, early clinical and radiographic outcomes of this prosthesis were promising. We believe the early radiolucent lines were probably due to the gap at the implant and bone interface, and they disappeared at the time of osseous integration. However, longer follow-up is necessary to determine the long-term durability and survivorship of this implant, particularly given the high incidence of postoperative osteolysis.

LEVEL OF EVIDENCE

Level IV, case series.

Functional and clinical outcomes of total ankle arthroplasty in elderly compared to younger patients

BACKGROUND

Total ankle arthroplasty (TAA) is becoming an increasingly utilized procedure for the management of end-stage ankle arthritis. Elderly patients are the fastest growing segment of the population in the western world, creating a unique challenge to the health economics of our era. Determining if elderly patients with end-stage ankle arthritis demonstrate the same improvements in clinical outcomes and functional measures of gait following TAA would be valuable. This can aid to evaluate the utilization of TAA in this enlarging cohort of our population.

METHODS

Consecutive series of twenty-one patients over the age of 70, who underwent TAA for end-stage ankle arthritis, was prospectively compared to a series of twenty-one patients aged 50-60, who underwent the same procedure by single surgeon during same time period. Clinical outcomes were measured with outcome scores including VAS pain score, AOFAS Ankle and Hindfoot Score, and the SF-36. Three-dimensional gait analysis was performed preoperatively and at a minimum of one year postoperatively, to measure temporal-spatial, kinematic, and kinetic parameters of gait. Mixed model multivariate statistical analysis was used to evaluate and compare the independent contributions to outcomes of the surgical intervention over time; of patient age; and of time-plus-age interaction, as these influenced both the clinical outcomes and the functional gait outcomes.

RESULTS

Statistically significant improvements in VAS pain scores, AOFAS ankle/hindfoot scores, and SF-36 scores were demonstrated in both age groups. Following surgery, there were improvements in all parameters of gait, including temporal-spatial parameters as step length and walking velocity; kinematic parameters, including, increase in total range of motion to a total of 17-19°; and kinetic parameters, including increase in ankle power and moment. The improvements both in clinical and gait outcomes were equivalent in the two age groups.

CONCLUSIONS

In this comparative study, it is shown that both elderly patients over the age of 70 and younger patients aged 50-60 demonstrated equivalent improvements clinical and gait outcomes following ankle arthroplasty. This may be important data both for clinical decision-making and the health economics for our ageing population.

Total ankle arthroplasty versus ankle arthrodesis-a comparison of outcomes over the last decade

BACKGROUND

The surgical treatment of end-stage tibiotalar arthritis continues to be a controversial topic. Advances in surgical technique and implant design have lead to improved outcomes after both ankle arthrodesis (AA) and total ankle arthroplasty (TAA), yet a clear consensus regarding the most ideal form of treatment is lacking. In this study, the outcomes and complications following AA and TAA are compared in order to improve our understanding and decision-making for care and treatment of symptomatic tibiotalar arthritis.

METHODS

Studies reporting on outcomes and complications following TAA or AA were obtained for review from the PubMed database between January 2006 and July 2016. Results from studies reporting on a minimum of 200 total ankle arthroplasties or a minimum of 80 ankle arthrodesis procedures were reviewed and pooled for analysis. All studies directly comparing outcomes and complications between TAA and AA were also included for review. Only studies including modern third-generation TAA implants approved for use in the USA (HINTEGRA, STAR, Salto, INBONE) were included.

RESULTS

A total of six studies reporting on outcomes following TAA and five reporting on outcomes following AA met inclusion criteria and were included for pooled data analysis. The adjusted overall complication rate was higher for AA (26.9%) compared to TAA (19.7%), with similar findings in the non-revision reoperation rate (12.9% for AA compared to 9.5% for TAA). The adjusted revision reoperation rate for TAA (7.9%) was higher than AA (5.4%). Analysis of results from ten studies directly comparing TAA to AA suggests a more symmetric gait and less impairment on uneven surfaces after TAA.

CONCLUSIONS

Pooled data analysis demonstrated a higher overall complication rate after AA, but a higher reoperation rate for revision after TAA. Based on the existing literature, the decision to proceed with TAA or AA for end-stage ankle arthritis should be made on an individual patient basis.

Salto Talaris Total Ankle Arthroplasty: Clinical Results at a Mean of 5.2 Years in 78 Patients Treated by a Single Surgeon

BACKGROUND

In recent years, the number of total ankle arthroplasty procedures performed has increased dramatically. We sought to report the clinical results of the largest cohort of patients treated with a modern fixed-bearing total ankle arthroplasty by a single surgeon.

METHODS

We retrospectively reviewed the charts of 78 consecutive patients (81 ankles) who underwent total ankle arthroplasty with a minimum clinical follow-up of 2 years. Sixty-three patients completed standardized questionnaires including the Foot and Ankle Disability Index (FADI), the Short Musculoskeletal Function Assessment (SMFA), the Short Form (SF)-36v2, and a visual analog scale (VAS) for pain. In addition, each patient underwent serial range-of-motion examination and radiographic implant evaluation at each follow-up appointment.

RESULTS

Implant survival was 97.5% at a mean follow-up time of 5.2 years. There was 1 revision of a tibial component and 1 revision of a talar component. Thirty-six patients underwent a concurrent procedure at the time of the index surgery, with the most common being removal of previous hardware. Seventeen patients underwent additional procedures following the index surgery, with the most common being gutter debridement. Total range of motion averaged 35.5° preoperatively and 39.9° postoperatively (p = 0.02). Fifty-seven ankles (70%) had >2 years of radiographic follow-up, and 25 ankles (31%) displayed evidence of lucency around a metallic component at the final radiographic follow-up. Outcome scores at a mean of 5.2 years revealed promising results for the cohort, with a mean VAS pain score of 17.7 and a mean FADI score of 79.1.

CONCLUSIONS

Modern fixed-bearing total ankle arthroplasty had excellent implant survival, improved plantar flexion and total range of motion, and had good-to-excellent functional outcome at a mean follow-up of 5.2 years.

LEVEL OF EVIDENCE

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

Outcomes of Bone Grafting of Bone Cysts After Total Ankle Arthroplasty

BACKGROUND

The operative treatment of bone cysts after total ankle replacements (TAR) is not well described. Bone cysts may cause component migration, implant failure, and pain. Surgery is performed on cysts with the goals of reducing pain and preventing component failure.

METHODS

We retrospectively evaluated a consecutive series of 726 primary TARs performed between January 1998 and May 2013 and identified those who had a subsequent bone cyst grafting procedure. We identified cyst location and method of treatment. Clinical outcomes including secondary procedures, infection rate, complications, and failure rate were recorded. Thirty-one patients were treated with a total of 33 operative procedures for bone cysts after TAR. Of these patients, 22 (71.0%) were males with an average age of 62.2 and median follow-up 65.9 months.

RESULTS

Intraoperatively, 22 tibial cysts (71.0%), 20 talar cysts (64.5%), 5 fibular cysts (16.1%), and 13 multiple cysts (41.9%) were treated. Allograft was used in 25 procedures (75.8%), calcium phosphate in 4 (12.1%), cement in 3 (9.1%), and autograft in 1 (3.0%). These procedures were supplemented by calcaneus autograft, allograft mixed with mesenchymal stem cells, platelet-rich plasma, recombinant human bone morphogenic protein-2, and demineralized bone matrix. There were no infections or wound complications. Of the 27 subjects with a successful second surgery, the success rate for bone grafting of cysts was 90.9% (95% CI: 50.8, 98.7%) at 24 months and 60.6% (95% CI: 25.1%, 83.4%) at 48 months. One patient needed a repeat bone grafting. The 4 failures observed postprocedure resulted in 3 tibial and talar component revisions, and 1 tibiotalocalcaneal (TTC) fusion.

CONCLUSIONS

Grafting bone cysts without revision of TAR was in general an effective and safe means for treating patients with peri-prosthetic bone cysts. Treatment with grafting and supplemental materials may improve implant survivorship and might improve the structural support surrounding the implant. Further exploration of the etiology of bone cysts may aid in the prevention and treatment of cystic formation in the TAR.

LEVEL OF EVIDENCE

Level IV, case series.

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.

Early radiographic and clinical results of Salto total ankle arthroplasty as a fixed-bearing device

BACKGROUND

Total ankle replacement has increased in popularity in the management of severe tibiotalar arthritis. Most previous clinical reports focused on mobile-bearing designs. This study evaluates early radiographic and clinical results of the Salto fixed bearing design.

METHODS

Twenty-three Salto fixed-bearing implants were prospectively studied. Records were reviewed for clinical outcome scores (VAS, AOFAS, SF36), subsequent surgeries, complications, radiographic data and implant survivorship. Average follow-up was 36 months.

RESULTS

Statistically significant improvements in VAS, AOFAS ankle/hindfoot scores, and SF36 scores were shown at an average of 3 years postoperatively. At 3 years followup, survivorship of the implant was 82.6% with any reoperation as the endpoint and 95.6% for revision or removal of components. Seven patients had radiolucencies around the implant, one of which required revision to arthrodesis.

CONCLUSION

The fixed-bearing Salto ankle replacement has comparable early radiographic and clinical results to reports of the mobile-bearing Salto of comparable followup.

LEVEL OF EVIDENCE

Level IV.

Incidence of revision after primary implantation of the Salto ® mobile version and Salto Talaris ™ total ankle prostheses: a systematic review

The incidence of revision of total ankle replacement prostheses remains unclear. We undertook a systematic review to identify the material relating to the incidence of revision after implantation of the Salto(®) mobile version and Salto Talaris™ total ankle prostheses. Studies were eligible for inclusion only if they had involved primary total ankle replacement with these prostheses and had included the incidence of revision. Eight studies involving 1,209 Salto(®) mobile version prostheses, with a weighted mean follow-up period of 55.2 months, and 5 studies involving 212 Salto Talaris™ total ankle prostheses, with a weighted mean follow-up period of 34.9 months, were included. Forty-eight patients with Salto(®) mobile version prostheses (4%) underwent revision, of whom 24 (70.5%) underwent ankle arthrodesis, 9 (26.5%) metallic component replacement, and 1 (3%) below-the-knee amputation. Five (2.4%) Salto Talaris™ total ankle prostheses underwent revision (3 metallic component replacement and 2 ankle arthrodeses). Restricting the data to the inventor, design team, or disclosed consultants, the incidence of revision was 5.2% for the Salto(®) mobile version and 2.6% for the Salto Talaris™ total ankle prostheses. In contrast, data that excluded these individuals had an incidence of revision of 2.8% for the Salto(®) mobile version and 2.0% for the Salto Talaris™ total ankle prostheses. We could not identify any obvious difference in the etiology responsible for the incidence of revision between these mobile- and fixed-bearing prostheses. The incidence of revision for the Salto(®) mobile version and Salto Talaris™ total ankle prostheses was lower than those reported through systematic review for the Agility™ and Scandinavian Total Ankle Replacement™ systems without obvious selection (inventor) or publication (conflict of interest) bias.

AKILE™ total ankle arthroplasty: Clinical and CT scan analysis of periprosthetic cysts

INTRODUCTION

Despite good clinical results following total ankle replacement (TAR), the development of large periprosthetic cysts (>400 mm(2)) in the medium-term is a source of concern.

OBJECTIVE

The primary objective of this study was to detect any large periprosthetic cysts in a cohort of AKILE™ patients using radiographs and CT scans, and then to compare these findings to published ones.

MATERIAL AND METHODS

A total of 127 TAR procedures were performed between June 1995 and January 2012. We retrospectively reviewed 68 cases with the newest AKILE™ implant design that had a minimum follow-up of 36 months. The average follow-up was 81 ± 33 months; eight patients were lost to follow-up. The outcomes consisted of analyzing radiographs (A/P and lateral weight bearing views, Meary view and lateral views of flexion/extension) and helical CT scans, performing clinical evaluations (range of motion, AOFAS score, Foot Function Index, pain levels) and determining the survivorship of TAR implants.

RESULTS

TAR survival at 5 years was 79% for in situ implants and 62% for revision-free implants. The AOFAS score improved from 33.7 ± 14.7 to 77.1 ± 15.1 (out of 100) and the pain sub-score was 30.2 ± 9.7 (out of 40) at the last follow-up. The average ankle range of motion was 32.3° ± 12.7° on the radiographs. CT scan revealed Type A cysts (<200 mm(2)) under the talar implant in 52% of cases and in the tibia in 50% of cases; these cysts were smaller than 100 mm(2) in 80% of cases and had no effect on the implants. No periprosthetic cysts larger than 400 mm(2) in size were identified.

DISCUSSION

The medium-term functional results and survivorship are comparable to those reported for other TAR designs. The incidence of cysts was low overall and there were no large-diameter cysts, which should improve long-term survival. The implant's design and materials likely played a role in preserving the periprosthetic bone stock. The AKILE™ TAR has distinctive features related to the low rate of large periprosthetic cysts in the medium-term.

LEVEL OF EVIDENCE

IV (retrospective case series).

[Implantation of a Salto 2 total ankle prosthesis]

AIM OF SURGERY

Operative treatment of advanced primary and secondary arthritis of the ankle was carried out with the aim of achieving pain-free movement and retention of mobility.

INDICATIONS

Surgery is indicated when conservative therapy is no longer sufficient for treatment of arthritis of the ankle with painful limited movement, sufficient bony joint conditions and correctable instability or axis malpositioning.

CONTRAINDICATIONS

Surgery is not recommended with general surgical or anesthesiological contraindications, rampant infections, severe disturbances of peripheral perfusion, bony defects in areas relevant for anchoring, unstable soft tissue conditions, talus necrosis >30 %, manifest osteoporosis and severe non-correctable instability or malpositioning.

OPERATION TECHNIQUE

Tibial and talar bone resection was carried out via ventral access to the ankle through an incision and if present, soft tissue correction of instability after insertion of test components. Cement-free implantation of the original implants followed by subtle reconstruction of the extensor retinaculum and layer for layer closure of the wound.

ADDITIONAL INTERVENTIONS

Additional measures were necessary on the periarticular soft tissues, the hindfoot and lower leg due to movement restrictions, instability and axis malpositioning which could be carried out in a one or two stage procedure depending on the extent and morphology.

RESULTS

Between February 2009 and February 2010 a total of 115 patients (52 % with posttraumatic arthritis) received a cement-free implantation with a Salto 2 prosthesis. Additional corrective interventions were carried out in the presence of varus and valgus deformities. The degree of movement for dorsal extension and plantar flexion could be increased by an average of 8.3°. The interventions resulted in a significant reduction in pain from an average preoperative visual analogue pain scale (VAS) score of 7.8 (range 5-10) to an average postoperative score of 1.9 (range 0-6.1).

A controlled, comparative study of a fixed-bearing versus mobile-bearing ankle arthroplasty

BACKGROUND

Total ankle arthroplasty is available with fixed-bearing (FB) or mobile-bearing (MB) versions, and there is little consensus on the benefits and drawbacks of each type. This study aimed to compare clinical outcomes of statistically paired series of FB and MB versions of the same ankle prosthesis.

METHODS

The study was a multicenter retrospective comparison between 2 groups: the FB group of 33 consecutive Talaris cases and the MB group of 33 "paired" Salto cases, selected from a database of 313 consecutive cases to statistically match etiology, age, and preoperative American Orthopaedic Foot & Ankle Society (AOFAS) score. All patients were operated upon with the same operative technique and received identical pre- and postoperative clinical and radiographic assessments. The mean follow-up was 24 months for the FB group and 23 months for the MB group.

RESULTS

There was no statistical difference between results of the 2 groups in terms of accuracy of positioning, clinical and radiographic mobility, and morbidity. The most recent postoperative AOFAS scores were higher for the FB group than for the MB group (P = .05). Radiolucent lines were observed in 4 FB patients versus 13 MB patients (P = .02). Subchondral cysts were noted in 1 FB patient and in 8 MB patients (P = .01).

CONCLUSION

There was no notable difference in clinical performance of the FB and MB implants with the numbers available. This short-term study demonstrated that FB ankle arthroplasty had results equivalent to, if not better than, MB ankle arthroplasty. Longer follow-up is necessary to determine the success of this new generation of ankle arthroplasty.

LEVEL OF EVIDENCE

Level III, retrospective case control study.

Short to midterm clinical and radiographic outcomes of the Salto total ankle prosthesis

BACKGROUND

Total ankle arthroplasty (TAA) has become an increasingly effective treatment option for tibiotalar arthritis. The purpose of this study was to evaluate the short to midterm clinical and radiographic outcomes of the Salto fixed bearing total ankle prosthesis.

METHODS

We retrospectively reviewed the radiographs and patient records of 74 consecutive patients with 75 TAA implants from January 2007 to April 2011. The average age was 60.6 years (range, 41-82) with 41 females and 33 males. The average clinical follow-up was 43 months (range, 24-73 months). Radiographs were reviewed for areas of radiolucency and cystic changes around the talar and tibial implants, as well as for implant migration using standardized tibal, talar, talocalcaneal, and tibial slope angular measurements. The validated Foot and Ankle Outcome Score (FAOS), Short Form-12 (SF-12), and Visual Analog Scale (VAS) were used as subjective patient outcome measures. Kaplan Meier (K-M) curves were created for implant survivorship with revision of components as an endpoint and for return to the operating room for any reason.

RESULTS

Total ankle survivorship was 98%. Thirteen patients returned to the operating room for any reason. There was 1 deep infection, and no ankles were converted to an arthrodesis. Average ankle dorsiflexion and plantarflexion improved from 4.3 ± 3.3 to 8.7 ± 5.6 degrees (P = .0008) and 24 ± 11 to 29 ± 7 degrees (P = .04), respectively. Patients showed significant improvements in all subscales of the FAOS (P < .0001). The physical component of the SF-12 significantly improved from 30 ± 8 to 41 ± 13 (P < .0001), but this was not observed with the mental component (52 ± 1 vs 53 ± 1, P = .55). The mean VAS for patient satisfaction was 9 (range, 2-10). Two patients had component migration (1 tibial and 1 talar component), neither of which required a revision procedure. Six ankles had a total of 9 radiolucent lines with a radiographically stable implant, and no patients had cystic changes.

CONCLUSION

This is one of the first articles to report clinical and radiographic outcome data for the fixed bearing version of this prosthesis. We observed significant improvements in subjective outcome measures and range of motion with a 98% component survivorship at short to midterm follow-up. Longer follow-up will be necessary to determine the durability of this implant.

LEVEL OF EVIDENCE

Level IV, case series.

Functional results and complication analysis after total ankle replacement: early to medium-term results from a Portuguese and Spanish prospective multicentric study

BACKGROUND

Ankle arthroplasty is increasingly being used to treat end-stage ankle osteoarthritis.

METHODS

Between January 2005 and January 2011, 159 patients have been included in an ongoing prospective multicentric study analysing the results of total ankle arthroplasty in Portugal and Spain. 119 patients (119 replacements) were available for review and were evaluated for range of motion (ROM), clinical status (American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score), complications and survivorship rate.

RESULTS

Mean follow-up was 39 months. A total of 17 complications were reported, with 7 leading to subsequent surgery (94.1% survivorship rate). Of these, there were two infections (98.3% survivorship rate), two painful subtalar arthritis, one instability, one malalignment and one tibial bone cyst. Complications not requiring further surgery were 6 intra-operative malleolar fractures and 4 cases of skin necrosis.

CONCLUSIONS

Adequate patient selection and a thorough knowledge of the surgical technique are mandatory to reduce the number of complications and increase ankle arthroplasty survivorship.

Prospective study of the effect on gait of a two-component total ankle replacement

BACKGROUND

The purpose of this study was to evaluate the functional outcome as measured by prospective gait analysis of patients undergoing total ankle arthroplasty using a 2-component Salto Talaris total ankle prostheses with a fixed polyethylene bearing.

METHODS

Twenty-one patients with severe ankle arthritis who underwent unilateral total ankle arthroplasty using a 2-component Salto Talaris device with a fixed polyethylene bearing were studied prospectively. Mean age was 69 years in 16 female and 5 male patients, and mean follow-up was 37.2 (range, 24-50) months. Three-dimensional gait analysis was performed using a 12-camera digital-motion capture system preoperatively and repeated at a minimum of 2 years postoperatively. Temporospatial measurements included velocity, cadence, step length, and support times. Measured kinematic parameters included sagittal plane range of motion of the ankle, knee, and hip. Kinetic parameters included sagittal plane ankle power and ankle plantarflexion moment.

RESULTS

There was significant improvement in temporospatial parameters, including step length (P = .014) and walking velocity, which increased from 0.9 to 1 m/s (P = .01). Kinematic results showed sagittal plane range of motion of the ankle increased significantly from a mean of 15.8 degrees preoperatively to 20.6 degrees (P = .00005) postoperatively with the increase occurring primarily in dorsiflexion. Kinetic results showed ankle peak power increased from a mean of 0.7 Nm/kg to 1.1 Nm/kg (P = .004).

CONCLUSIONS

A prospective study of gait in patients undergoing total ankle arthroplasty using a 2-component Salto Talaris device with a fixed polyethylene bearing showed, at midterm follow-up, significant improvements in multiple parameters of gait when compared to the patients' own preoperative function.

LEVEL OF EVIDENCE

Level IV, prospective case series.

The outcome of total ankle replacement

We performed a systematic review and meta-analysis of modern total ankle replacements (TARs) to determine the survivorship, outcome, complications, radiological findings and range of movement, in patients with end-stage osteoarthritis (OA) of the ankle who undergo this procedure. We used the methodology of the Cochrane Collaboration, which uses risk of bias profiling to assess the quality of papers in favour of a domain-based approach. Continuous outcome scores were pooled across studies using the generic inverse variance method and the random-effects model was used to incorporate clinical and methodological heterogeneity. We included 58 papers (7942 TARs) with an interobserver reliability (Kappa) for selection, performance, attrition, detection and reporting bias of between 0.83 and 0.98. The overall survivorship was 89% at ten years with an annual failure rate of 1.2% (95% confidence interval (CI) 0.7 to 1.6). The mean American Orthopaedic Foot and Ankle Society score changed from 40 (95% CI 36 to 43) pre-operatively to 80 (95% CI 76 to 84) at a mean follow-up of 8.2 years (7 to 10) (p < 0.01). Radiolucencies were identified in up to 23% of TARs after a mean of 4.4 years (2.3 to 9.6). The mean total range of movement improved from 23° (95% CI 19 to 26) to 34° (95% CI 26 to 41) (p = 0.01).

Our study demonstrates that TAR has a positive impact on patients’ lives, with benefits lasting ten years, as judged by improvement in pain and function, as well as improved gait and increased range of movement. However, the quality of evidence is weak and fraught with biases and high quality randomised controlled trials are required to compare TAR with other forms of treatment such as fusion.

Cite this article: Bone Joint J 2013;95-B:1500–7.

The total ankle arthroplasty learning curve with third-generation implants: a single surgeon's experience

BACKGROUND

Renewed interest in total ankle arthroplasty (TAA) has developed globally as a result of recent literature supporting new-generation implants as a viable alternative to arthrodesis. The literature also demonstrates a learning curve among surgeons adopting TAA. The purpose of this study is to better define this learning curve for surgeons using third-generation implants.

METHODS

Charts and radiographs were reviewed for the initial 26 TAA procedures performed by the senior author. Three third-generation implants were used: SBi (Small Bone Innovations) STAR, Salto Talaris, and Wright Medical INBONE. We report perioperative and early postoperative complications.

RESULTS

Two perioperative fractures occurred in the first 9 cases, and the incidence subsequently dropped to 0 (P = .0431). Two cases of component malalignment occurred in the first 3 patients receiving the STAR implant, and the incidence then dropped to 0 (P = .0034). Five wound complications (4 minor and 1 major) occurred, all in the final 14 patients. No cases of nerve injury, tendon laceration, or deep vein thrombosis occurred. Two patients returned to the operating room as a result of complications, and the total perioperative and early postoperative complication rate was 27%.

CONCLUSION

The observed rate of perioperative and early postoperative complications in this case series was low relative to other similar-sized studies, suggesting that third-generation implants can reduce adverse events. Our results demonstrate that some common complications could be avoided altogether (nerve/tendon injuries), some decreased quickly with experience (intraoperative fractures and component malpositioning), and some persisted unchanged throughout this study (wound complications). These findings should influence surgical training, surgeon willingness to adopt this procedure, and patient counseling.

LEVELS OF EVIDENCE

Therapeutic, Level IV, Retrospective Case Series.

HINTEGRA total ankle replacement: survivorship analysis in 684 patients

BACKGROUND

Total ankle replacement is increasingly recommended for patients with end-stage ankle osteoarthritis. We analyzed the survivorship of 722 arthroplasties performed with one type of three-component total ankle prosthesis.

METHODS

Seven hundred and seventy-nine primary total ankle arthroplasties (741 patients) were performed between May 2000 and July 2010 with use of the HINTEGRA three-component prosthesis. A logistic multiple regression model was used to identify independent risk factors for prosthesis failure in 684 patients (722 ankles). The mean time to final follow-up (and standard deviation) was 6.3 ± 2.9 years.

RESULTS

Seven hundred and twenty-two ankles (684 patients) were available for survivorship analysis at the latest follow-up. The overall survival rates were 94% and 84% after five and ten years, respectively. Sixty-one ankles had a revision arthroplasty (twenty-seven both components, thirteen the tibial component only, and fourteen the talar component only) or were converted to a fusion (seven ankles).There were no polyethylene failures. There were no amputations. The generation category of the prosthesis, the cause of ankle osteoarthritis, and the age of the patient were identified as independent risk factors for prosthesis failure.

CONCLUSIONS

The midterm survivorship of the HINTEGRA implant was comparable with that of other third-generation total ankle replacements.

Early prospective clinical results of a modern fixed-bearing total ankle arthroplasty

BACKGROUND

Several fixed-bearing total ankle arthroplasty systems are available in the United States. We report on the early clinical results of the largest known cohort of patients in the United States who received a Salto Talaris total ankle replacement for the treatment of end-stage arthritis of the ankle.

METHODS

We prospectively followed sixty-seven patients with a minimum clinical follow-up of two years. Patients completed standardized assessments and underwent physical examination, functional assessment, and radiographic evaluation preoperatively and at six weeks, three months, and six months postoperatively and yearly thereafter through their most recent follow-up.

RESULTS

Implant survival at a mean follow-up time of 2.8 years was 96% when metallic component revision, removal, or impending failure was used as the end point. Three patients developed aseptic loosening, and all instances involved the tibial component. One of the three patients underwent revision to another fixed-bearing total ankle arthroplasty system, one patient is awaiting revision surgery, and the third patient has remained minimally symptomatic and fully functional without additional surgery. Forty-five patients underwent at least one additional procedure at the time of the index surgery. The most common concurrent procedure performed was a deltoid ligament release (n = 21). Eight patients underwent additional surgery following the index arthroplasty, most commonly debridement for medial and/or lateral impingement (n = 4). As of the most recent follow-up, patients demonstrated significant improvement in pain scores, American Orthopaedic Foot & Ankle Society hindfoot score, and functional scores.

CONCLUSIONS

Early clinical results indicate that the Salto Talaris fixed-bearing total ankle arthroplasty system can provide significant improvement in pain, quality of life, and standard functional measures in patients with end-stage ankle arthritis.

LEVEL OF EVIDENCE

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

Revision of the aseptic and septic total ankle replacement

Total ankle replacement has become a popular treatment of symptomatic end-stage ankle osteoarthritis. Contemporary total ankle replacement systems provide more anatomic and biomechanically sound function. However, longevity is still limited and long-term results of modern total ankle replacement designs are not available. In the case of failure, conversion into arthrodesis has remained the treatment of choice but at the cost of hindfoot function and potential degeneration of the adjacent joints. Thus, revision total ankle replacement by exchange of the prosthetic components represents an attractive solution. This article focuses on revision total ankle replacement and conversion to ankle arthrodesis.

Tibio-talo-calcaneal arthrodesis with retrograde compression intramedullary nail fixation for salvage of failed total ankle replacement: a systematic review

Failed total ankle replacement is a complex problem that should only be treated by experienced foot and ankle surgeons. Significant bone loss can preclude revision total ankle replacement and obligate revision though a complex tibio-talo-calcaneal arthrodesis. A systematic review of the world literature reveals a nonunion rate of 24.2%. A weighted mean of modified American Orthopaedic Foot and Ankle Society Ankle and Hindfoot Scale demonstrated fair patient outcomes of 58.1 points on an 86-point scale (67.6 points on a 100-point scale). Complications were observed in 38 of 62 (62.3%) patients reviewed, with the most common complication being nonunion.

History of total ankle replacement

Attempts at ankle replacement have existed for at least 50 years. Time has essentially eliminated constrained, cemented, first-generation ankle replacements. Although some two-component, more anatomic, designs are still used with varying success, three-component "mobile bearing" ankle prostheses are winning the race of evolution. Not only have implants change over the years, but also the patients and surgeons. Surgeons specialize, improving their surgical outcomes and expanding the indications for total ankle replacement in technically demanding complex ankles. High-demand, younger patients, but also obese ones, are potential candidates for a total ankle replacement. This article provides a review of the history of total ankle replacement.

Techniques and pitfalls with the Salto prosthesis: our experience of the first 15 years

The Salto total ankle replacement system has shown to be a viable alternative in the treatment of symptomatic arthritis. However, although outcomes after total ankle replacement are promising, an exact analysis of surgical technique could help to improve them. Based on a 15 years experience with the Salto Total Ankle replacement system, the uthors discuss the surgical technique and its pitfalls, its inications and limitations in current practice.

Total ankle arthroplasty - three-component total ankle arthroplasty in western France: a radiographic study

INTRODUCTION

Although the literature has confirmed the short and intermediate term efficacy of three-component mobile-bearing total ankle arthroplasty (TAA), the development of progressive periprosthetic bone abnormalities threatens the intermediate and long term survival of these implants. The aim of this study was to evaluate whether TAA quality requirements were met and analyze radiological changes in arthroplasties performed by members of the French Western Orthopedics Society.

MATERIALS AND METHODS

This retrospective multicenter study included 173 patients who underwent three-component mobile-bearing arthroplasty between 1997 and 2010 in eight centers in western France. The etiology was osteoarthritis (OA) in 78% of cases and rheumatoid arthropathy in 13% of cases. The radiographic assessment included preoperative and final postoperative standing anteroposterior (AP) and lateral view radiographs. Radiographs were reviewed for ankle alignment, improper implant positions, and periprosthetic bone anomalies. Intraprosthetic range of motion was evaluated in 111 cases on dynamic radiographs.

RESULTS

Mean follow-up was 34 months (± 5). Fifteen percent of the cases presented implant malposition. Alignment was normal in 76% of cases. Intraprosthetic range of motion was 20.5° (± 3) in the cases that were evaluated. Bone cysts were observed in 33% of cases, radioluncencies in 72%, ossifications in 39%, migration of the tibial component in 5% and migration of the talar component in 27%. The latter were correlated to a range of motion of less than 15°. Additional surgery was necessary in 8% of cases to revise implants and/or for conversion to arthrodesis.

DISCUSSION

The high rate of radiolucencies and bone cysts at a mean follow-up of 2.8 years is of concern and these arthroplasties should be closely monitored. Stiff ankles seemed to be at a higher risk for subsidence.

LEVEL OF EVIDENCE

IV - Retrospective study.