A Prospective Study of Four Total Ankle Arthroplasty Implants by Non-Designer Investigators

Median age of patients undergoing total ankle replacement has not significantly changed between 1999 and 2023: A systematic review of prospective studies

INTRODUCTION

Total ankle replacement (TAR) is an effective treatment for end-stage osteoarthritis. The aim of this systematic review was to assess the age of patients undergoing TAR in prospective comparative studies. Our hypothesis is that the age reported in most recent papers might be lower than those reported in older papers.

METHODS

This systematic review was performed using Pubmed, Scopus, EMBASE and Cochrane databases. Only Level I and II studies dealing with TAR were included. Data regarding demographics, study design, number of cohorts in each study, year of publication and year/years in which surgery was performed were extracted. A two-fold analysis was conducted building groups of patients based on the year of publication and creating 1) two groups (before and after the median year) and 2) three groups (using tertiles) in order to compare age of patients operated in different period of times. A comparison was also performed considering the median year of surgery for patients undergoing TAR.

RESULTS

Overall 59 cohorts (42 studies, published between 1999 and 2023; median year of publication: 2017) were included (6397 ankles, 6317 patients, median age 63 years). The difference between the median age for 27 cohorts published until 2016 (weighted median 63 years; IQR, 62.5-64) and the median age for 32 cohorts published after 2017 (weighted median 63.2 years; IQR, 63-67.8) was not statistically significant (p = 0.09). The division in tertiles did not reveal any significant change in the weighted median age at surgery (T1 (1999-2014; 63.2 years; IQR, 62.8-64.1), T2 (2015-2018; 63 years; IQR,63-63.5) and T3 (2019-2023; 63.2 years; IQR, 62.6-67.8)) over time (p = 0.65). The median age of patients operated between 1999 and 2008 vs 2009 and 2023 (data from 48 cohorts) was not different either (p = 0.12).

CONCLUSION

According to this review of prospective studies published between 1999 and 2023, the median age for patients undergoing TAR over the last two decades has been 63 years, remaining steady with no significant changes over time.

LEVEL OF EVIDENCE

Level II - systematic review including Level I and Level II studies.

Early experience with a 3-D printed porous surface, fixed-bearing, total ankle arthroplasty: A minimum of 2-year follow-up

BACKGROUND

This is a pilot study reviewing patients undergoing ankle replacement with the 3-D printed INFINITY™ with ADAPTIS™ total ankle arthroplasty (TAA) system.

METHODS

A retrospective review was conducted of patients with a minimum two-year follow-up who underwent TAA with the INFINITY™ with ADAPTIS™ implant system. Outcome measures include implant survivorship, complications with subsequent reoperations, patient reported outcomes, and radiologic subsidence or radiolucency.

RESULTS

Thirty patients were included with median follow-up of 26 months (range, 24-36). Implant survival rate was 90% (27/30). Two patients experienced linear radiolucency > 2 mm: one required a revision TAA secondary to tibial subsidence; the other patient was asymptomatic and nonprogressive on serial radiographs. No cystic radiolucencies > 5 mm were identified. VAS, PROMIS PF, and FADI scores improved significantly.

CONCLUSION

TAA performed with the 3-D printed INFINITY™ with ADAPTIS™ implant technology led to ninety percent short term implant survivorship and improvement in patient reported outcomes with comparable results to other 4th generation arthroplasty systems as a treatment modality for end-stage ankle arthritis.

LEVEL OF EVIDENCE

Level III, Retrospective cohort study, Prognostic.

Clinical Outcomes and Registry Data in Total Ankle Arthroplasty

Total ankle arthroplasty (TAA) is an effective treatment for end-stage ankle arthritis consistently demonstrating good to excellent outcomes, even when considering factors such as deformity, patient age, bilaterality, and arthritis etiology. There is little consensus in the literature with regard to preferred patient-reported outcome metrics (PROMs) for assessing outcomes, although all metrics generally improve following TAA. Several countries have successful registries to track longevity of TAA in populations; however, PROMs are generally not successfully tracked in registries. A trend toward consensus on outcome metrics and collaborative registries is warranted to optimize patient selection and outcomes in TAA.

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.

Two-Year Survivorship and Patient-Reported Outcomes of a Prospectively Enrolled Cohort of INFINITY Total Ankle Arthroplasties

BACKGROUND

The INFINITY total ankle implant is a widely and successfully used option for total ankle arthroplasty. The purpose of this study is to assess the 2-year survivorship, complication rates, patient-reported outcomes, and radiologic findings of prospectively enrolled patients undergoing a fixed-bearing total ankle arthroplasty (TAA). This study sought to determine if factors such as traditional vs patient-specific instrumentation, preoperative degree of arthritis, deformity, or etiology of arthritis impact surgical or clinical outcomes.

METHODS

A total of 143 prospectively enrolled patients (148 ankles) underwent TAA with a fixed-bearing total ankle implant between 2017 and 2019 at 9 different institutions by 9 different surgeons. A total of 116 completed 2-year follow-up. Patients were stratified by instrumentation used, degree of preoperative deformity, the Canadian Orthopaedic Foot and Ankle Society (COFAS) grading system, and etiology of arthritis. Outcomes used included implant survivorship and adverse events within 2 years of surgery. Additionally, patient-reported outcomes and radiographs were collected at 6-month, 1-year, and 2-year postoperatively. PROMs used included Ankle Osteoarthritis Score (AOS), Patient-Reported Outcomes Measurement Information System (PROMIS) global health score, the Foot and Ankle Outcome Score (FAOS), and patient satisfaction (rated from excellent to poor).

RESULTS

Implant survivorship at 2 years was 97.79%. There were 17 reoperations (11.5%), with 4 of the implants requiring revision (2.7%). Significant improvements in all PROMs were observed among all subgroups at all postoperative time points without significant variation between subgroups. Patients classified as COFAS type 2 arthritis preoperatively demonstrated significantly more improvement in FAOS Total Symptom Score at the 1- and 2-year measurements than COFAS type 3 patients at both time points.

CONCLUSION

Total ankle arthroplasty with a fixed-bearing implant system is a safe and reliable treatment option for patients with end-stage arthritis regardless of degree of deformity or COFAS grading.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

STAR® total ankle replacements with BONIT® coating: A prospective 2-17 year follow-up study of 474 ankles from a single center

BACKGROUND

Different coatings of the metal implants of STAR prostheses have been used since 1999. In Europe metal implants with a double calcium-phosphate coating (BONIT) on a titanium sprayed surface have been available since 1999.

METHODS

We present a 2-17 year follow-up of a consecutive series from a single center with 474 STAR ankle replacements where the BONIT type of coating has been used.

RESULTS

55 prostheses (12%) have been revised, the majority of them due to fracture of the mobile bearing. 22 prostheses (5%) have been converted to an arthrodesis. Analysis of survival of the specific components showed an estimated 10-year survival rate of the tibia component, talus component and polyethylene mobile bearing of 99%, 98% and 84%, respectively. The corresponding estimated 15-year survival was 98%, 98% and 74%, respectively.

CONCLUSION

This study showed an extraordinary high survival rate of the metal implants.

LEVEL OF EVIDENCE

Level III, prospective cohort series.

Developing a core outcome set for foot and ankle disorders in rheumatic and musculoskeletal diseases: A scoping review and report from the OMERACT 2022 foot and ankle special interest group session

OBJECTIVES

Foot and ankle involvement is common in rheumatic and musculoskeletal diseases, yet high-quality evidence assessing the effectiveness of treatments for these disorders is lacking. The Outcome Measures in Rheumatology (OMERACT) Foot and Ankle Working Group is developing a core outcome set for use in clinical trials and longitudinal observational studies in this area.

METHODS

A scoping review was performed to identify outcome domains in the existing literature. Clinical trials and observational studies comparing pharmacological, conservative or surgical interventions involving adult participants with any foot or ankle disorder in the following rheumatic and musculoskeletal diseases (RMDs) were eligible for inclusion: rheumatoid arthritis (RA), osteoarthritis (OA), spondyloarthropathies, crystal arthropathies and connective tissue diseases. Outcome domains were categorised according to the OMERACT Filter 2.1.

RESULTS

Outcome domains were extracted from 150 eligible studies. Most studies included participants with foot/ankle OA (63% of studies) or foot/ankle involvement in RA (29% of studies). Foot/ankle pain was the outcome domain most commonly measured (78% of studies), being the most frequently specified outcome domain across all RMDs. There was considerable heterogeneity in the other outcome domains measured, across core areas of manifestations (signs, symptoms, biomarkers), life impact, and societal/resource use. The group's progress to date, including findings from the scoping review, was presented and discussed during a virtual OMERACT Special Interest Group (SIG) in October 2022. During this meeting, feedback was sought amongst delegates regarding the scope of the core outcome set, and feedback was received on the next steps of the project, including focus group and Delphi methods.

CONCLUSION

Findings from the scoping review and feedback from the SIG will contribute to the development of a core outcome set for foot and ankle disorders in RMDs. The next steps are to determine which outcome domains are important to patients, followed by a Delphi exercise with key stakeholders to prioritise outcome domains.

A combined FE-hybrid MCDM framework for improving the performance of the conical stem tibial design for TAR with the addition of pegs

BACKGROUND AND OBJECTIVES

The conical stemmed design of the tibial component for total ankle replacement (TAR) (example Mobility design) uses a single intramedullary stem for primary fixation. Tibial component loosening is a common mode of failure for TAR. Primary causes of loosening are lack of bone ingrowth due to excessive micromotion at the implant-bone interface and bone resorption due to stress shielding after implantation. The fixation feature of the conical stemmed design can be modified with the addition of small pegs to avoid loosening. The aim of the study is to select the improved design for conical stemmed TAR using a combined Finite Element (FE) hybrid Multi-Criteria Decision-Making (MCDM) framework.

METHODS

The geometry and material properties of the bone for FE modeling were extracted from the CT data. Thirty-two design alternatives with varying pegs in number (one, two, four, eight), location (anterior, posterior, medial, lateral, anterior-posterior, medial-lateral, equally spaced), and height (5 mm, 4 mm, 3 mm, 2 mm) were prepared. All models were analyzed for dorsiflexion, neutral, and plantarflexion loading. The proximal part of the tibia was fixed. The implant-bone interface coefficient of friction was taken as 0.5. The implant-bone micromotion, stress shielding, volume of bone resection, and surgical simplicity were the important criteria considered for evaluating the performance of TAR. The designs were compared using a hybrid MCDM method of WASPAS, TOPSIS, EDAS, and VIKOR. The weight calculations were based on fuzzy AHP and the final ranks on the Degree of Membership method.

RESULTS

The addition of pegs decreased the mean implant-bone micromotions and increased stress shielding. There was a marginal decrease in micromotion and a marginal increase in stress shielding when the peg heights were increased. The results of hybrid MCDM indicated that the most preferable alternative designs were two pegs of 4 mm height in the AP direction to the main stem, two pegs of 4 mm height in the ML direction, and one peg of 3 mm height in the A direction.

CONCLUSIONS

Outcomes of this study suggest that the addition of pegs can reduce the implant-bone micromotions. Modified three designs would be useful by considering implant-bone micromotions, stress shielding, volume of bone resection, and surgical simplicity.

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.

Midterm Outcomes of the INBONETM II Total Ankle Arthroplasty

As the number of total ankle arthroplasties (TAA) performed continues to increase, understanding midterm outcomes can guide both implant selection and preoperative patient counseling. The purpose of this study was to investigate midterm results including the survival rate and reasons for revision for the INBONE^TM II TAA. Patients undergoing a primary TAA with the study implant and minimum of 4.6 years postoperative follow-up were reviewed from a prospectively collected database. The primary outcome was implant survival. Secondary outcomes included coronal plane radiographic alignment, evaluation for cysts and osteolysis, and failure mode when applicable. Patients were eligible for inclusion in this study if they had a minimum of 4.6-year follow-up TAA with the study implant. Eighty-five TAAs in 83 patients were eligible for inclusion; 75 TAA in 73 patients were included in the study. The mean duration of follow up was 6.2 ± 0.9 years (range 4.7-8.1 years). Thirty-six percent of the TAAs had a preoperative coronal plane deformity of at least 10^°, and 12% of the TAAs had at least 20^°. There were 6 (8%) implant failures that occurred at a mean 2.0 ± 1.4 years postoperatively. Eighty-one percent of the TAAs had no reoperation events in the follow-up period. Midterm outcomes at a minimum of 4.6 years postoperatively in patients undergoing a TAA using this implant demonstrates acceptable implant survival, an approximately 20% reoperation rate, and maintenance of coronal plane alignment.

Consumer Interest in Total Ankle Replacements Over the Last 10 Years: A Google Trends™ Analysis From 2009 to 2019

With an aging population, the incidence of osteoarthritis (OA) continues to grow. After exhausting conservative therapy for many forms of OA, patients regularly opt for surgical intervention in the form of total joint replacement surgery. One form, total ankle replacement, has continued to gain favorability in the medical community. Improved implant design and surgical technique have enabled success rates of total ankle replacements to approach those of the hip and knee. As a new and improving therapy to address end-stage ankle OA, knowledge of patient-interest has yet to be determined. We used search inquiry data for the keywords "ankle arthritis" "ankle replacement" and "ankle fusion" available from Google Trends™ to identify trends in patient and geographic interest from 2009 to 2019. Search inquiries significantly increased for all keywords over time (p < .001). Trend analysis over this 10-year period revealed a strong correlation for ankle arthritis (0.88) and ankle replacement (0.76). Moreover, the correlation between "ankle arthritis" and "ankle replacement" was strong (0.83) during this period. The geographic distribution of these search terms showed the greatest increase in interest for the keywords "ankle arthritis" "ankle replacement" and "ankle fusion" in Arizona, New York, and Virginia respectively. Results of this study illustrate a similar increasing patient interest in ankle arthritis and ankle replacements. This data can be used effectively identify, educate, and treat populations interested in ankle replacements. To the best of our knowledge, this is the first study to utilize Google Trends™ to analyze patient interest in foot and ankle surgery.

Corin ankle arthroplasty: Case-series

BACKGROUND

Total Ankle Arthroplasty (TAA) is complex and can bring a wide variety of complications. Implant revision rates can vary from 4% to 8% in 5 years. Recent publications have shown good results in the short and intermediate follow-up and high patient satisfaction. The pre- and postoperative evaluation of these patients should include physical examination and objective radiographic measurements, which may have predictive value for implant failures and survivorship. In this paper we will present the results obtained with 29 patients treated with the Zennith (Corin Group, UK) total ankle prosthesis in Brazil.

METHODS

This paper presents the results obtained with 29 patients treated with the Corin-Zennith prosthesis in three tertiary hospitals in Brazil, with an average follow-up of 5 years. The patients were submitted to clinical and radiographic evaluation. There were seventeen women and twelve men, ranging in age from 35 to 76 years, who were submitted to surgical treatment between January 16, 2013 and May 5, 2017.

RESULTS

Seven patients (24%) presented cysts, being 4 (13.7%) tibial cysts and 3 (10.3%) tibial and talar cysts. Six patients (20.6%) presented talar subsidence and 3 (10.3%) presented tibial subsidence. Three patients (10.3%) presented component wear. VAS reduced and AOFAS and ROM increased in the post-operative period. The development of Cysts was associated with the theta angle and the difference in LTS (between the post and preoperative period) was associated with tibial subsidence. The complications rate was 44.8%, the revision rate was 6.9% and the survivorship rate was 93.1%.

CONCLUSION

The Corin-Zennith prosthesis demonstrated to be a safe implant for improving functional parameters. Functional outcomes were not influenced for most commonly measured radiographic parameters. Further studies are needed to better understand these associations.

Outcomes of trabecular metal total ankle replacement: a longitudinal observational cohort study of 239 consecutive cases from the Swedish Ankle Registry

BACKGROUND AND PURPOSE

Information on outcomes after some modern total ankle replacement (TAR) designs is scarce. We therefore examined outcomes after trabecular metal (TM) TAR in Sweden by use of data from the national registry.

PATIENTS AND METHODS

On December 31, 2020, 239 primary TM TARs had been reported to the Swedish Ankle Registry. We analyzed prosthesis survival probability, using exchange or permanent extraction of components as endpoint for 239 protheses with mean follow-up of 2.2 years (0.1-6.6), risk of revision, as well as patient-reported outcome measures (SEFAS/EQ-5D/EQ-VAS) and satisfaction with surgery.

RESULTS

7/239 prostheses (3%) had been revised by December 31, 2020. We found an overall prosthesis survival probability of 95% (95% CI 89-98) after 3 years. 2 years after surgery 81% of the answering patients were satisfied or very satisfied with surgery and patients reported median SEFAS 36 (max 48), EQ-5D 0.90 (max 1), and EQ-VAS 80 (max 100).

INTERPRETATION

We found short- to mid-term outcomes after TM TAR to be at least as good as after other TAR designs regarding prosthesis survival and patient-reported satisfaction.

Total Ankle Arthroplasty Can Be Safely and Effectively Performed in the Community Hospital Setting: A Case Series of 65 Patients

The use of total ankle arthroplasty has expanded over the past decade, primarily due to improvements in implant design and survivorship that have significantly reduced the high failure rates observed in first-generation implants. A retrospective review of 65 consecutive patients undergoing primary total ankle arthroplasty with a single senior orthopedic surgeon in a community hospital from January 2014 to December 2019 was performed. All procedures were performed for end stage osteoarthritis, with the most common secondary diagnoses being Achilles contracture (23%), retained hardware (17%) and calcaneovalgus deformity (11%). Preoperatively, patients averaged 10.45 ̊ ± 10.00 ̊ of non-weightbearing dorsiflexion and 30.00 ̊ ± 8.79 ̊ of plantarflexion. Postoperatively, patients averaged 13.33 ̊ ± 7.62 ̊ dorsiflexion, and 25.48 ̊ ± 7.87 ̊ of plantarflexion. A total of 8 (12.3%) patients required reoperation, and average time to reoperation was 1.55 ± 1.58 years. Implant failure, defined as reoperation requiring prosthesis removal, occurred in 2 (3.1%) patients, with an average time to failure of 342 days (105 days in failure due to periprosthetic joint infection and 582 days in failure due to subsidence). Patients undergoing total ankle arthroplasty at our institution had a 12.3% reoperation rate, and a 96.9% implant survival rate over an average follow-up period of 2.42 years, results that compare favorably with previously reported outcomes. Based on these findings, we suggest that this procedure, which is often offered only in academic tertiary care facilities, can be safely and effectively performed by experienced surgeons in the community hospital setting.

Total Ankle Arthroplasty Survivorship, Complication, and Revision Rates in Patients Younger Than 55 Years

Total ankle replacement has become a viable alternative to ankle arthrodesis in the surgical management of advanced ankle arthritis. Total ankle replacement has generally been reserved for patients who are older and for those who will have a lower demand on the replacement. The purpose of the current study is to review patient outcomes, complications, and implant survival in patients younger than 55 years who underwent total ankle replacement at a single institution. A single-center chart and radiographic review was performed of consecutive patients who underwent total ankle replacement for treatment of end-stage ankle arthritis. All surgeries were performed by 1 of 5 fellowship-trained foot and ankle surgeons at a single institution. A total of 51 patients met inclusion criteria with a mean follow-up of 31.2 months (SD = 16.2). Implant survival was 94%, There were 7 major complications (13%) requiring an unplanned return to the operating room and 8 minor complications (15%) that resolved with conservative care. The results of this study show that total ankle replacement is a viable treatment option for patients younger than 55 years.Levels of Evidence: A retrospective case series.

Long-Term Survival of HINTEGRA Total Ankle Replacement in 683 Patients: A Concise 20-Year Follow-up of a Previous Report

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

Patient reported outcome measures in ankle replacement versus ankle arthrodesis - A systematic review

OBJECTIVES

Compare the functional outcomes of comparative studies of ankle arthrodesis (AA) and total ankle replacements (TAR).

DESIGN

Systematic review using PRISMA guidelines.

DATA SOURCES

Medline, Cochrane and EMBASE databases in July 2020.

ELIGIBILITY CRITERIA

Studies that directly compared TAR and AA which reported patient reported outcomes measures (PROMs) of pain, function and quality of life.

DATA EXTRACTION AND SYNTHESIS

Two authors independently reviewed all papers. PROMs were allocated into pain, function or quality of life domains. Two summary statistics were created to allow for analysis of the PROMs. These statistics were the mean difference in post-operative score and the mean difference in the change of score.

RESULTS

1323 papers were assessed of which 20 papers were included. 898 ankle arthrodesis and 1638 ankle replacements were evaluated. The mean follow up was 3.3 years (range 0.5-13.0 years). AA patients had a mean age of 55.7 (range 20-82) and TAR 62.5 (range 21-89). There was major heterogeneity in outcomes used. We were unable to find a significant difference between the reported change in PROMs following TAR and AA. 29.3% of PROMs and their subscores showed TAR had better outcomes, 68.7% showed no significant difference and only 2.0% showed AA to have better outcomes.

CONCLUSIONS

The majority of published studies found equality in patient reported outcomes following TAR and AA although the quality of the studies was of low-level evidence. There is an urgent need for randomised controlled studies to definitively answer this important clinical question.

Comparison of Clinical Outcomes Between Ceramic-Based Total Ankle Arthroplasty with Ceramic Total Talar Prosthesis and Ceramic-Based Total Ankle Arthroplasty

BACKGROUND

Total ankle arthroplasty (TAA) has become one of the standard surgical treatments for patients with end-stage ankle osteoarthritis (OA). In recent years, TAA with total talar prosthesis (combined TAA) has been used for ankle OA patients with talar osteonecrosis, with severe talar collapse, or with subtalar joint OA. The purpose of this study was to investigate the functional and clinical outcomes of combined TAA, compared with conventional TAA.

METHODS

Forty-six ankles (44 patients, 32 women/12 men) that underwent conventional TAA with mean follow-up of 42 months, and 26 ankles (25 patients, 18 women/7 men) that underwent combined TAA with mean follow-up of 46 months were included. Clinical outcomes, which included ankle range of motion (ROM), the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale, the Self-Administered Foot Evaluation Questionnaire (SAFE-Q), and complications were compared between the groups.

RESULTS

The preoperative ROM was significantly worse in combined TAA for both dorsiflexion and plantarflexion; however, in the final ROM, there was no significant difference between the groups. There was no significant difference in JSSF scale and SAFE-Q between the groups. Revision rate was 10.9% in conventional TAA and 0% in combined TAA.

CONCLUSION

In this small series, at an average of 3.5 years, we found no significant difference in clinical results between conventional TAA and combined TAA; however, the revision rate was higher in conventional TAA.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

The INFINITY Total Ankle Prosthesis: Outcomes at Short-Term Follow-up

BACKGROUND

The INFINITY total ankle prothesis remains the most widely used fourth-generation total ankle arthroplasty (TAA) system in the United States. The purpose of the present study was to assess radiographic outcomes for INFINITY at short-term follow-up.

METHODS

All patients who underwent primary TAA with INFINITY between August 2015 and June 2018 at a single institution and who were at least 1 year postoperative were included. A total of 55 ankles with a mean follow up 22 months (range, 12-43 months) met the criteria. Weightbearing radiographs were assessed using coronal and sagittal alignment parameters preoperatively, at 6 to 8 weeks postoperatively, and at the most recent follow-up. Medical records and charts were reviewed and revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook at el, respectively.

RESULTS

Overall, INFINITY survivorship was 98.2%. Coronal and sagittal tibiotalar alignment improved after surgery (P < .001, P = .09, respectively), and was maintained during the latest follow-up (P = .62, P = .47, respectively). Only 1 ankle (1.8%) required early revision; while 5 (9.1%) indicated non-implant-related revision; 85.5% required no reoperation. In nineteen ankles (34.5%), postoperative periprosthetic lucency was observed; most were not progressive (17 ankles, 89.5%). Twelve complications (3 high grade, 3 intermediate, and 6 low grade) in 11 ankles (20%) were recorded according to the Glazebrook classification system.

CONCLUSION

INFINITY survivorship was 98.2% at a mean of 1.8 years of follow-up, and only 1 ankle required prosthetic revision. Additional studies with longer follow-up are warranted for fourth-generation TAA prostheses.

LEVELS OF EVIDENCE

Level IV: Case series.

Lateral Instability in Total Ankle Arthroplasty: A Comparison Between the Brostrom-Gould and Anatomic Lateral Ankle Stabilization (ATLAS)

BACKGROUND

Lateral ankle instability is not uncommon after osseous cuts and soft tissue releases are performed during Total Ankle Arthroplasty (TAA), particularly with varus malalignment. The purpose of the present study was to compare the outcomes of ankles that underwent TAA with concurrent Brostrom-Gould (BG) or Anatomic Lateral Ankle Stabilization (ATLAS) at a minimum of 1-year follow-up.

METHODS

Thirty-eight TAAs underwent BG (21 INFINITY, 4 CADENCE) or ATLAS (13 INBONE-2) between August 2015 and February 2019 at a single institution and were at least 1 year postoperative (mean 18.3 months, range: 12-40). Baseline patient demographics, characteristics, and operative factors were assessed via medical record and chart reviews. Radiographs parameters were measured preoperatively, at 6 weeks postoperative, and during the latest follow-up. Revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook et al, respectively. Univariate and multivariate analyses were performed.

RESULTS

Survivorship for TAA with concurrent BG/ATLAS was 97%. Overall, TAA with concurrent BG had higher incidences of early TAA revision (4%), recurrent instability (4%), reoperation (16%), and complications (29%) compared to ATLAS. Postoperative coronal and sagittal tibiotalar alignment changes were significant for both groups (P < .001, P = .014); however, the differences were greater for ATLAS (P = .045, P < .001).

CONCLUSION

The present study is the first to compare outcomes between techniques for addressing ankle instability in the TAA population. At short-term follow-up, anatomic reconstruction produced better outcomes than the traditional BG procedure. Additional comparative studies between techniques to address instability in the TAA population are warranted.

LEVEL OF EVIDENCE

Level III: Retrospective cohort study.

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.

Magnetic Resonance Imaging Around Metal at 1.5 Tesla: Techniques From Basic to Advanced and Clinical Impact

ABSTRACT

During the last decade, metal artifact reduction in magnetic resonance imaging (MRI) has been an area of intensive research and substantial improvement. The demand for an excellent diagnostic MRI scan quality of tissues around metal implants is closely linked to the steadily increasing number of joint arthroplasty (especially knee and hip arthroplasties) and spinal stabilization procedures. Its unmatched soft tissue contrast and cross-sectional nature make MRI a valuable tool in early detection of frequently encountered postoperative complications, such as periprosthetic infection, material wear-induced synovitis, osteolysis, or damage of the soft tissues. However, metal-induced artifacts remain a constant challenge. Successful artifact reduction plays an important role in the diagnostic workup of patients with painful/dysfunctional arthroplasties and helps to improve patient outcome. The artifact severity depends both on the implant and the acquisition technique. The implant's material, in particular its magnetic susceptibility and electrical conductivity, its size, geometry, and orientation in the MRI magnet are critical. On the acquisition side, the magnetic field strength, the employed imaging pulse sequence, and several acquisition parameters can be optimized. As a rule of thumb, the choice of a 1.5-T over a 3.0-T magnet, a fast spin-echo sequence over a spin-echo or gradient-echo sequence, a high receive bandwidth, a small voxel size, and short tau inversion recovery-based fat suppression can mitigate the impact of metal artifacts on diagnostic image quality. However, successful imaging of large orthopedic implants (eg, arthroplasties) often requires further optimized artifact reduction methods, such as slice encoding for metal artifact correction or multiacquisition variable-resonance image combination. With these tools, MRI at 1.5 T is now widely considered the modality of choice for the clinical evaluation of patients with metal implants.

Analysis of 408 Total Ankle Arthroplasty Adverse Events Reported to the US Food and Drug Administration From 2015 to 2018

Background. Total ankle arthroplasty (TAA) use has increased with newer generation implants. Current reports in the literature regarding complications use data extracted from high-volume centers. The types of complications experienced by lower-volume centers may not be reflected in these reports. The purpose of this study was to determine a comprehensive TAA adverse event profile from a mandatory-reporting regulatory database. Methods. The US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database was reviewed from 2015 to 2018 to determine reported adverse events for approved implants. Results. Among 408 unique TAA device failures, the most common modes of failure were component loosening (17.9%), intraoperative guide or jig error (15.4%), infection (13.7%), and cyst formation (12.7%). In addition, the percentage distribution of adverse event failure types differed among implants. Conclusion. The MAUDE database is a publicly available method that requires mandatory reporting of approved device adverse events. Using this report, we found general agreement in types of complications reported in the literature, although there were some differences, as well as differences between implants. These data may more accurately reflect a comprehensive profile of TAA complications as data were taken from a database of all device users rather than only high-volume centers.Levels of Evidence: NA.

Total Ankle Arthroplasty With Anatomic Lateral Ankle Stabilization (ATLAS) in Moderate and Severe Pre-operative Varus Alignment

The purpose of the present study was to assess the early clinical and radiographic outcomes for patients who underwent TAA and Anatomic Lateral Ankle Stabilization (ATLAS) using synthetic graft for instability in moderate and severe preoperative varus alignment. Seven ankles with moderate or severe varus alignment underwent TAA with a 3^rd generation prothesis (INBONE-2) and ATLAS using synthetic graft between September 2018 and February 2019 at a single institution, and were at least 1 year postoperative (mean 13.3 months, range 12-15). Medical records and charts were reviewed for revisions, reoperations, and complications. Weightbearing radiographs were assessed using tibiotalar alignment parameters preoperatively, and during the latest follow-up. Survivorship for INBONE-2 with ATLAS was 100%; recurrent instability was not observed. Symptomatic talonavicular joint arthritis was recorded for a single patient 12 months postoperatively; no revisions, or reoperations were performed. Coronal alignment improved significantly from 17.7 ± 9.3 (range, 10.1-33.6) to 2.3 ± 1.2 (range, 0.9-4.4) degrees (p < .006), and all ankles achieved neutral alignment in a single stage. Regarding sagittal alignment, 2 ankles (28.5%) were translated anteriorly and the rest were neutral (71.5%) preoperatively. Significant posterior translation was observed and during the latest follow-up, 4 ankles were neutral (57.1%) and 3 posterior (42.9%) (p < .009). Satisfactory outcomes were observed at a minimum of 1-year follow-up for patients with moderate or severe varus alignment who underwent TAA with INBONE-2 and ATLAS. ATLAS may afford advantages over previously described repair techniques. Comparative studies between the Brostrum-Gould and ATLAS are warranted.

Outcome Reporting in Total Ankle Arthroplasty: A Systematic Review

Total ankle arthroplasty is an increasingly utilized treatment for ankle arthritis due to decreasing failure rates and improved outcomes. However, the literature on this procedure remains heterogeneous with large variability in outcome reporting methods. PRISMA guidelines were used to systematically review outcome reporting measures used in prospective studies and randomized control trials on total ankle arthroplasty published in 15 high-impact journals between Jan 1, 2009-May 1, 2020. A total of 43 studies were included and outcome measures were grouped into seven categories: pain, subjective function, patient satisfaction, complications, objective function, implant survivorship, and imaging. The most common topic of study was implant design followed by differences in outcomes when comparing total ankle arthroplasty and arthrodesis. The most commonly reported outcome measure was post-surgical complications. No study reported on all seven categories, while 22 (51.2%) studies reported on four or more. Subjective measures had significant variability with fifteen different Patient Reported Outcome Measures used across the studies. While the included studies were quite comprehensive, there was little consistency in reporting outcomes after total ankle arthroplasty. With improving outcomes and techniques in total ankle arthroplasty, and thus an expected increase in utilization and number of published studies, efforts should be made to use commonly employed outcome reporting methods to facilitate comparison of results across studies.

Total Ankle Arthroplasty Radiographic Alignment Comparison Between Patient-Specific Instrumentation and Standard Instrumentation

BACKGROUND

Several benefits are published supporting patient-specific instrumentation (PSI) in total ankle arthroplasty (TAA). This study seeks to determine if TAA with PSI yields different radiographic outcomes vs standard instrumentation (SI).

METHODS

Sixty-seven primary TAA patients having surgery using PSI or SI between 2013 and 2015 were retrospectively reviewed using weightbearing radiographs at 6-12 weeks postsurgery. Radiographic parameters analyzed were the medial distal tibia angle (MDTA), talar-tilt angle (TTA), anatomic sagittal distal tibia angle (aSDTA), lateral talar station (LTS), and talar component inclination angle (TCI). A comparison of the 2 groups for each radiologic parameter's distribution was performed using a nonparametric median test and Fisher exact test. Furthermore, TAAs with all radiographic measurements within acceptable limits were classified as "perfectly aligned." The rate of "perfectly aligned" TAAs between groups was compared using a Fisher exact test with a significance of .05.

RESULTS

Of the 67 TAAs, 51 were done with PSI and 16 with SI. There were no differences between groups in MDTA (P = .174), TTA (P = .145), aSDTA (P = .98), LTS (P = .922), or TCI angle (P = .98). When the rate of "perfectly aligned TAA" between the 2 groups were compared, there was no significant difference (P = .35).

CONCLUSION

No significant radiographic alignment differences were found between PSI and SI implants. This study showed that both techniques achieve reproducible TAA radiographic coronal and sagittal alignment for the tibial component when performed by experienced surgeons. The talar component's sagittal alignment is similar whether or not PSI was used but is noticeably different from normal anatomic alignment by design.

LEVEL OF EVIDENCE

Level III, retrospective cohort study using prospectively collected data.

Early Experience With the CADENCE Total Ankle Prosthesis

A number of 2-component, fourth-generation total ankle arthroplasty prostheses have been introduced to the market. The purpose of the present study was to present early experience with the CADENCE total ankle prosthesis. All patients who underwent primary total ankle arthroplasty using the prosthesis between August 2016 and June 2018 at a single institution and who were at least 1 year postoperative were included. A total of 32 ankles with a mean follow-up of 24 (range, 12-33) months met the criteria. Weightbearing radiographs were assessed using coronal and sagittal alignment parameters preoperatively, at 6 weeks postoperative, and at the most recent follow-up. Medical records and charts were reviewed and revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook et el, respectively. Coronal and sagittal tibiotalar alignment significantly improved after surgery (p < .001, p < .005), and was maintained during the latest follow-up (p = .44, p = .30). Two (6.3%) ankles underwent early revision for aseptic loosening; while 6 (18.8%) underwent a nonrevisional reoperation. Nine (28.1%) ankles presented a total of 13 (4 high grade, 2 intermediate, and 7 low) complications according to the Glazebrook classification. The most common was intraoperative periprosthetic medial malleolar fracture (5 ankles, 15.6%), a low-grade complication. The present study is the first to report early outcomes and experience with the CADENCE total ankle. Overall, survivorship was 94% at short-term follow-up of 2 years. As with all arthroplasty devices, surgeons new to the prosthesis should be cognizant of the potential learning curve. Intraoperative medial malleolar fracture was found to be the most common complication.

Risk Factors for Early Failure of Fourth Generation Total Ankle Arthroplasty Prostheses

A number of 2-component, fourth generation total ankle arthroplasty (TAA) prostheses have been introduced to the market in the past few years, as the popularity and indications for TAA have continued to expand. The purpose of the present study was to identify independent risk factors for the early failure of fourth generation TAA prostheses. A total of 97 ankles underwent TAA with a fourth generation prostheses (INFINITY, CADENCE) between August 2015 and June 2018 at a single institution and were at least 6 months postoperative (mean 18.3 months, range 6-43). The primary outcome assessed was the need for revision surgery, defined as removal of 1 or both metal components for any reason, excluding infection. Baseline patient demographics, characteristics, radiographic alignment parameters, and distal tibia cortical bone thickness (CBT) were assessed. Revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook et al, respectively. Univariate and multivariate analyses were performed. Three ankles (3.1%) underwent revision surgery for aseptic loosening at a mean of 24.3 (range, 16-31) months; all had a CBT <4 mm. Independent predictors for reoperation were CBT <4 mm, presence of diabetes, and ipsilateral hindfoot fusion (p = .04). No associations were identified for purported risk factors (age, body mass index, and coronal deformity). The present study is the first to suggest a potential relationship between reduced CBT of the distal tibia, and TAA failure. Additional studies are warranted to better understand the role of bone density in TAA survivorship.

The Hintegra total ankle replacement: survivorship, failure modes and patient reported outcomes in seventy consecutive cases with a minimum five year follow-up

PURPOSE

The Hintegra total ankle replacement (TAR) has been widely used worldwide for ankle arthroplasty since its introduction in 2000. The implant survivorship, patient reported outcomes, rate of periprosthetic cyst formation and reoperation rates are variably reported. The purpose of this study is to determine the functional outcomes and survivorship of the Hintegra TAR, in consecutive cases by multiple surgeons in a single UK institution, with a minimum of five year follow-up.

METHODS

A retrospective review of prospectively collected data for 70 consecutive Hintegra TAR cases performed between 2010 and 2014. Data collected included patient demographics, complications, reoperations, revisions and patient reported outcome measures (PROMS: AOS, MOX-FQ, pain VAS and EQ-5D 3L).

RESULTS

Seventy patients underwent Hintegra TAR (54 male/16 female) with an average age of 69 (range 48-84 years). Mean follow up was 76 months (range 60-104), 10 patients died during the follow-up. Implant survivorship was 81.7% at most recent follow-up. The commonest radiographic finding was periprosthetic cysts (n = 28, 40%): size range (7-40 mm). Nine patients required re-operation: six periprosthetic cyst debridement and grafting at a mean of 61 months (range 27-91), one lateral gutter debridement, one periprosthetic fracture and one debridement for deep infection. PROMS data was available for the majority of patients. Mean final follow-up scores were total AOS 35 (range: 0-97), MOX-FQ 36 (range: 2-93), pain VAS 34.6 (range: 0-100) and EQ-5D 3L Index 0.69 (range: 0.08-1.00).

CONCLUSION

Our experience demonstrates implant survivorship similar to other TAR studies. We have identified a high incidence of periprosthetic cysts and would recommend ongoing surveillance of these patients.

Long-term Functional Results of Total Ankle Arthroplasty in Stiff Ankles

BACKGROUND

Total ankle arthroplasty (TAA) is advocated over ankle arthrodesis to preserve ankle motion (ROM). Clinical and gait analysis studies have shown significant improvement after TAA. The role and outcomes of TAA in stiff ankles, which have little motion to be preserved, has been the subject of limited investigation. This investigation evaluated the mid- to long-term functional outcomes of TAA in stiff ankles.

METHODS

A retrospective study of prospectively collected functional gait data in 33 TAA patients at a mean of 7.6 (5-13) years postoperatively used 1-way analysis of variance and multivariate regression analysis to compare among preoperative and postoperative demographic data (age, gender, body mass index, years postsurgery, and diagnosis) and gait parameters according to quartiles of preoperative sagittal ROM.

RESULTS

The stiffest ankles had a mean ROM of 7.8 degrees, compared to 14.3 degrees for the middle 2 quartiles, and 21.0 degrees for the most flexible ankles. Patients in the lowest quartile (Q1) also had statistically significantly lower step length, speed, max plantarflexion, and power preoperatively. Postoperatively, they increased step length, speed, max plantarflexion, and ankle power to levels comparable to patients with more flexible ankles preoperatively (Q2, Q3, and Q4). They had the greatest absolute and relative increases in these parameters of any group, but the final total ROM was still statistically significantly the lowest.

CONCLUSION

Preoperative ROM was predictive of overall postoperative gait function at an average of 7.6 (range 5-13) years. Although greater preoperative sagittal ROM predicted greater postoperative ROM, the stiffest ankles showed the greatest percentage increase in ROM. Patients with the stiffest ankles had the greatest absolute and relative improvements in objective function after TAA, as measured by multiple gait parameters. At intermediate- to long-term follow-up, patients with stiff ankles maintained significant functional improvements after TAA.

LEVEL OF EVIDENCE

Level III, comparative study.

Long-term follow-up of Bologna-Oxford (BOX) total ankle arthroplasty

PURPOSE

The purpose of this retrospective study was to evaluate the long-term results with a minimum of ten years follow-up of primary Bologna-Oxford (BOX) TAA.

METHODS

Between December 2004 and December 2009, 80 patients (82 ankles) underwent a primary BOX TAA performed by a single senior surgeon, expert in foot and ankle surgery. Pain and functional outcomes were analysed using Visual Analogue Scale (VAS) for pain, American Orthopaedic Foot & Ankle Society (AOFAS) scoring system, Foot Functional Index Disability and Pain (FFI-Disability, FFI-Pain) score for comparative analysis.

RESULTS

A total of 52 patients (54 implants) in a cohort of 80 (82 implants) were examined at a minimum ten years follow-up. Twenty implants out of 54 underwent implant failure (37 %) and 34 patients were enrolled in the present study. The mean VAS for pain decreased significantly from 8.5 ± 1.2 to 2.9 ± 2.2 (p<0.01) and the mean AFOAS score changed from 28.6 ± 11.8 pre-operatively to 72.7 ± 16.9 (p<0.01) at last follow-up. Ninety-seven percent was satisfied with a mean FFI-Disability score that improved from 77.6 ± 19.3 to 26.7 ± 25.4 (p<0.01) and FFI-Pain score that decreased from 76.2 ± 14.2 to 31.4 ± 25.6 (p<0.01). We calculated post-operative alignment using alpha, beta and gamma angles with no difference at long-term follow-up. The survival rate of the implant was 66% at ten years of follow-up.

CONCLUSIONS

Our data suggest that BOX TAA is an implant with a good patient satisfaction rate at long-term follow-up; therefore, it is a valid option to increase the quality of life in subjects with end-stage osteoarthritis; however, long-term survivorship is unsatisfactory when compared to modern knee and hip implant.

Timeline for maximal subjective outcome improvement following total ankle arthroplasty

BACKGROUND

Maximal medical improvement (MMI) establishes the timepoint when patients no longer experience clinically significant improvements following surgery. The purpose of this investigation is to establish when patients achieve MMI following total ankle arthroplasty (TAA) through the use of patient reported outcome measures (PROMs).

METHODS

A systematic review to identify studies on TAA which reported consecutive PROMs for two years postoperatively was performed. Pooled analysis was done at 6 months, 12 months, and 24 months. Clinically significant improvement was defined as improvement between time intervals exceeding the minimal clinically important difference.

RESULTS

Twelve studies and 1514 patients met inclusion criteria. Clinically significant improvement was seen up to 6 months postoperatively in both the American Orthopaedic Foot and Ankle Society Ankle Hindfoot Score and Visual Analog Scale scoring systems. The Short Musculoskeletal Function Assessment Dysfunction and Bother subsections showed maximal clinically significant improvement by 1 year postoperatively.

CONCLUSION

Following TAA, MMI is seen by one year postoperatively. Physicians may allocate the majority of resources within the first year when most of the improvement is perceived. This data may help inform preoperative counseling as it establishes a timeline for MMI.

LEVEL OF EVIDENCE

IV.

Differences in 30-day complications associated with total ankle arthroplasty and ankle arthrodesis: A matched cohort study

BACKGROUND

The objective of this study was to identify whether total ankle arthroplasty (TAA) was associated with greater risk for 30-day complications and/or greater financial burden in comparison to ankle arthrodesis (AA).

METHODS

The PearlDiver Patient Records Database was queried to identify all patients who underwent an arthroscopic/open AA or TAA from 2006 to 2013. The two cohorts were then matched in a 1:1 manner to control for comorbidities and demographics. Postoperative complications were compared between the two cohorts, in addition to the associated costs with respect to each procedure.

RESULTS

No significant differences in risk for postoperative complications were noted between the two procedures with the numbers available. Significant differences were demonstrated in total length of hospital stay (LOS), with a mean of 2.13 days for the TAA cohort and 2.42 days for the AA cohort (p < 0.001). Higher mean total hospital costs were noted for TAA (x¯ = $62,416.62) compared to AA (x¯ = $37,737.43, p < 0.001); however, TAA was associated with a higher mean total reimbursement (x¯ = $12,254.43) than AA (x¯ = $7915.72, p < 0.001).

CONCLUSION

With no notable differences in 30-day complication rates, TAA remains a viable alternative to AA in the appropriately selected patient and provides the ability to preserve tibiotalar motion resulting in superior functional scores. Additionally, TAA demonstrated higher total costs to implant, but also greater reimbursement, in line with the recent literature suggesting TAA to be a cost-effective alternative to AA.

LEVEL OF EVIDENCE

III Retrospective study.

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

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

Analysis of early failure rate and its risk factor with 2157 total ankle replacements

The failure rate of TAA is still higher than that of other joint replacement procedures. This study aimed to calculate the early failure rate and identify associated patient factors. Data from the Korean Health Insurance Review and Assessment Service database from 2009 to 2017 were collected. We evaluated patients who had TAA as a primary surgical procedure. Early failure was defined as conversion to revision TAA or arthrodesis after primary TAA within five years. Patients with early failure after primary TAA were designated as the "Failure group". Patients without early failure and who were followed up unremarkably for at least five years after primary TAA were designated as the "No failure group". Overall, 2157 TAA participants were included. During the study period, 197 patients developed failure within five years postoperatively, for an overall failure rate of 9.1%. Significant risk factors for early failure were history of chronic pulmonary disease, diabetes, peripheral vascular disease, hyperlipidemia, dementia, and alcohol abuse. A significant increase of odds ratio was found in patients with a history of dementia, chronic pulmonary disease, and diabetes. Surgical indications and preoperative patient counseling should consider these factors.

Six year results of the Rebalance mobile bearing total ankle replacement

BACKGROUND

We report the outcomes of a prospective consecutive series of 267 total ankle replacements (TARs) using a new mobile bearing Rebalance® prosthesis.

METHODS

Between April 2011 and December 2018, 267 consecutive Rebalance® prostheses were implanted in 255 patients at 3 different centers. Estimated survival curves with 95% confidence intervals were produced with the Kaplan-Meier method. 110 ankles were followed for at least 5 years and clinical and radiological outcomes were assessed in 92 of these ankles.

RESULTS

Twenty-one ankles were revised at a mean of 34 (7-60) months. The estimated survival was 90% (95% CI 86-95) at 5 years and 88.3% (95% CI 83.-94 at 6 years. The ankles followed for at least 5 years demonstrated a median Likert score of 1 (1-4). Radiolucent zones were detected in 14% and osteolytic cysts in 3%.

CONCLUSION

The survival rate of the Rebalance prosthesis conforms with other reports of similar designs. The satisfaction rate was high. Radiological zones and osteolytic cysts were found at a lower rate than usually reported for mobile bearing TARs. These results favour further use of this implant.

Does Patient-Specific Instrumentation Have a Higher Rate of Early Osteolysis Than Standard Referencing Techniques in Total Ankle Arthroplasty? A Radiographic Analysis

Introduction: Patient-specific instrumentation (PSI) has been developed for total ankle arthroplasty (TAA), with proven benefits. One concern regarding PSI is the need for more soft tissue dissection in order to accurately position the PSI guides, which has the theoretical disadvantage of increased osteolysis. The purpose of our study is to compare the incidence and magnitude of osteolysis for the INFINITY Total Ankle System between PSI and standard referencing (SR) techniques. Methods: Sixty-seven patients who underwent primary TAA using Prophecy (PSI) or SR technique between 2013 and 2015 were reviewed in a retrospective observational study. Osteolysis was assessed on radiographs at 2 years. The incidence was calculated by binomial distribution. The number of zones compromised and the magnitude of osteolysis was calculated using the median as a summary statistic and interquartile range as dispersion statistic. Fisher exact test was used to compare both groups, then a regression model was estimated to calculate the odds ratio for osteolysis. Results: Of the 67 TAAs, 51 were in the PSI group and 16 in the SR group. In the PSI group the incidence, number of compromised zones (CZ), and magnitude was 41% (25%-59%), 1 [1-2], and 2 [2-3], respectively. In the SR group these were 36% (13%-65%), 3 [2-3], and 3 [2-4], respectively. No significant differences were found (P = .46, P = .12, P = .33). A slightly higher risk of osteolysis was found in the PSI group (odds ratio = 1.33 [0.36-4.83]) (P = .46). The majority of lesions were in 1 zone with size of 2 to 5 mm (63% for all cohort, 64% PSI, 60% SR). Two cases underwent revision for aseptic loosening, 1 in the SR group and 1 in the PSI group. Conclusion: According to our data, there is no significant difference between PSI and SR in terms of risk, incidence, size and magnitude of osteolysis in the INFINITY Total Ankle System at 2 years. Levels of Evidence: Therapeutic, Level III, Retrospective cohort study.

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.

Outcomes of Total Ankle Replacement, Arthroscopic Ankle Arthrodesis, and Open Ankle Arthrodesis for Isolated Non-Deformed End-Stage Ankle Arthritis

BACKGROUND

End-stage ankle arthritis is a disabling condition that has a similar effect on morbidity, pain, and loss of function to hip arthritis. We compared clinical outcomes of total ankle replacement (TAR) involving the HINTEGRA prosthesis (Integra LifeSciences), arthroscopic ankle arthrodesis (AAA), and open ankle arthrodesis (OAA) in patients with isolated, non-deformed end-stage ankle arthritis.

METHODS

Patients ≥18 years old who underwent TAR, AAA, or OAA from 2002 to 2012 with a minimum follow-up of 2 years were retrospectively identified from the Canadian Orthopaedic Foot and Ankle Society (COFAS) Prospective Ankle Reconstruction Database. All patients had symptomatic COFAS Type-1 end-stage ankle arthritis without intra-articular or extra-articular deformity or surrounding joint arthritis. Clinical outcomes included the Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36). Revision was defined as removal of 1 or both metal ankle prosthesis components for TAR and as reoperation for malposition, malunion, or nonunion for AAA and OAA.

RESULTS

Analysis included 238 ankles (88 TAR, 50 AAA, and 100 OAA) in 229 patients with a mean follow-up of 43.3 ± 18.5 months. The TAR group had more female patients (55%; p = 0.0318) and a higher mean age (p = 0.0005). Preoperative AOS pain, disability, and total scores were similar for all groups. SF-36 physical and mental component summary scores were similar across groups, both preoperatively and postoperatively. Improvement in AOS total score was significantly larger for TAR (34.4 ± 22.6) and AAA (38.3 ± 23.6) compared with OAA (25.8 ± 25.5; p = 0.005). Improvement in AOS disability score was also significantly larger for TAR (36.7 ± 24.3) and AAA (40.5 ± 26.4) compared with OAA (26.0 ± 26.2; p = 0.0013). However, the greater improvements did not meet the minimal clinically important difference. The TAR group underwent more reoperations than AAA and OAA groups (p < 0.0001). Revision rates were similar for all 3 groups (p = 0.262).

CONCLUSIONS

AAA and OAA resulted in comparable clinical outcomes to TAR in patients with non-deformed, COFAS Type-1 end-stage ankle arthritis. The rate of component revision in patients who underwent TAR was similar to the rate of revision for patients who underwent AAA or OAA; however, TAR patients underwent a greater number of additional procedures. Overall, AAA and TAR involving the HINTEGRA prosthesis were not significantly different surgical options in terms of short-term outcomes; patients should be counseled regarding higher reoperation rates for TAR.

LEVEL OF EVIDENCE

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

Total Ankle Arthroplasty Survival and Risk Factors for Failure

BACKGROUND

Total ankle arthroplasty (TAA) is an increasingly selected treatment for end-stage ankle arthritis; however, failure and revision of the tibial and talar components remains an issue. Although multiple risk factors have been shown to contribute to early component revision, no study has looked at combining such risk factors into a predictive model that could potentially decrease revision rates and improve implant survival. This study aimed to develop a predictive model for TAA failure based on patient characteristics, patient-reported outcomes (PROs), and immediate postoperative radiographs.

METHODS

A retrospective review of a single-site ankle arthritis database was conducted. All patients with current-generation ankle replacements including the Hintegra and Infinity prostheses implanted between 2004 and 2015 and with complete postoperative radiographs taken between 6 and 12 weeks postoperatively were included. Eight coronal and sagittal radiographic parameters were assessed and performed twice by 2 independent orthopedic surgeons on included TAAs. These radiographic parameters were then analyzed in association with patient demographics and PRO. Advanced statistical methods including survival analysis were used to construct a predictive model for TAA survival. A total of 107 patients were included and analyzed with a median clinical follow-up of 49 months (minimum 24 months).

RESULTS

A predictive model was created, with 4 parameters identified as being statistically associated with TAA metal-component revision: diabetes mellitus, poor baseline Ankle Osteoarthritis Scale (AOS) score, excessively dorsiflexed talar component, and an anteriorly/posteriorly translated talus relative to the tibial axis. The presence of 3 parameters predicted TAA survival of 0.60 whereas presence of all 4 parameters predicted survival of only 0.13 in the period studied.

CONCLUSION

Our predictive model is based on a combination of patient factors, PROs, and radiographic TAA alignment. We believe it can be used by surgeons to predict failure in their TAA patients, thereby optimizing postoperative outcomes by improving patient selection and modifiable outcome-specific parameters.

LEVEL OF EVIDENCE

Level III, retrospective cohort study using prospectively collected data.

Total ankle arthroplasty and national registers: What is the impact on scientific production?

PURPOSE

The purpose of this systematic review was to analyze clinical studies on total ankle replacement (TAR) whose data were extracted from national registers.

METHODS

A systematic review of the literature, to identify all studies reporting outcomes after TAR, was performed. Two independent investigators performed the research using MEDLINE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Embase and Cochrane Databases (1950 to December 2017). The search terms used were "total ankle replacement" or "total ankle arthroplasty" AND "register" or "registers" or "registry" or "registries" or "national registry" or "national register".

RESULTS

Analysis of the literature included 18 articles from 2007 to 2017. Of these 5 articles performed a comprehensive analysis of the national registers, 5 articles evaluated complications and reasons of failure after TAR, 6 articles made a specific outcome register analysis, one article compared TAR and ankle arthrodesis while the last one analyzed the role of TAR in patients with rheumatoid arthritis.

CONCLUSIONS

Scientific publications extracted from national joint registers for total ankle replacement provide useful but heterogeneous information on implants survivorship, implant models and risk factors. There is still a discrepancy between the data reported by designers in clinical studies and the data reported by the registries. The centralization of registers in specialized hospitals with dedicated surgeons, the use of patient reported outcomes (PROMs) in association with surgeon assessments and periodical publications can improve the development of registries and consequently of the literature in this regard.

Ankle Arthritis

Ankle arthritis is a major source of morbidity impacting a younger working age population than hip and knee arthritis. Unlike the hip and knee, more than 70% of ankle arthritis cases are post-traumatic, with the remainder being inflammatory or primary arthritis. Nonoperative treatment begins with lifestyle and shoe-wear modifications and progresses to bracing, physical therapy, anti-inflammatory medications, and intra-articular injections. Ankle arthrodesis and total ankle arthroplasty are the 2 main surgical options for end-stage ankle arthritis, with debridement, realignment osteotomy, and distraction arthroplasty being appropriate for limited indications.

Total Replacement of Varus Ankle: Three-Component Prosthesis Design

In the past few decades, total ankle replacement (TAR) has become an increasingly recommended and accepted treatment in patients with end-stage ankle osteoarthritis. However, controversy still exists about the appropriate indications for TAR, specifically in ankles with coronal plane deformities. Although not explicitly proved, the long-term success of TAR seems to largely depend on the extent to which the surgeon is able to balance the ankle joint complex.

Risk Factors for Failure of Total Ankle Arthroplasty With a Minimum Five Years of Follow-up

BACKGROUND:

As the popularity of total ankle arthroplasty (TAA) increases and indications expand, surgeons require a better understanding of which patient factors are associated with implant failure. In this study, we aimed to use a large total ankle database to identify independent risk factors for implant failure at mid- to long-term follow-up.

METHODS:

A prospectively collected database was used to identify all patients who underwent primary TAA with a minimum 5 years' follow-up. The primary outcome was revision, defined as removal of one or both metal components; failures due to infection were excluded. Patient and clinical factors analyzed included age, sex, body mass index (BMI), smoking status, presence of diabetes, indication for TAA, implant, tourniquet time, and presence of ipsilateral hindfoot fusion. Preoperative coronal deformity and sagittal talar translation were assessed, as were postoperative coronal and sagittal tibial component alignment. Univariable and multivariable analyses were performed to identify predictors of implant failure. After excluding 5 ankles that failed because of deep infection, 533 ankles with a mean 7 (range, 5-11) years of follow-up met the inclusion criteria. Four implants were used: INBONE I, INBONE II, STAR, and Salto-Talaris.

RESULTS:

Thirty-four ankles (6.4%) were revised or removed a mean 4 (range, 1-9) years postoperatively. The only independent predictors of failure were the INBONE I prosthesis and ipsilateral hindfoot fusion ( P = .006 and P = .023, respectively).

CONCLUSIONS:

This is among the largest studies to analyze the relationship between TAA failure rates and multiple different patient, operative, and radiographic factors. Of note, age, BMI, and amount of deformity were not associated with higher failure rates. Only patients with ipsilateral hindfoot fusion or who received the INBONE I prosthesis were at significantly higher risk of implant failure.

LEVEL OF EVIDENCE:

Level III, retrospective cohort study.

Survivorship and long-term outcome of a consecutive series of 200 Scandinavian Total Ankle Replacement (STAR) implants

AIMS

We report the long-term clinical and radiological outcomes of a consecutive series of 200 total ankle arthroplasties (TAAs, 184 patients) at a single centre using the Scandinavian Total Ankle Replacement (STAR) implants.

PATIENTS AND METHODS

Between November 1993 and February 2000, 200 consecutive STAR prostheses were implanted in 184 patients by a single surgeon. Demographic and clinical data were collected prospectively and the last available status was recorded for further survival analysis. All surviving patients underwent regular clinical and radiological review. Pain and function were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scoring system. The principal 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 and the rate of failure calculated for each year.

RESULTS

A total of 84 patients (87 ankles) were alive by the end of this study. Of the surviving 84 patients (87 ankles; rheumatoid arthritis (RA), n = 40; OA, n = 47), 45 were women and 39 were men, with a mean age of 54 years (18 to 72 years) at the time of surgery. A total of 32 implants failed (16%), requiring revision surgery. The mean time to revision was 80 months (2 to 257). The implant survival at 15.8 years, using revision as an endpoint, was 76.16% (95% confidence interval (CI) 64.41 to 87.91). We found a steady but low decrease in survival over the study period. The mean AOFAS score improved from 28 (10 to 52) preoperatively to 61 (20 to 90) at long-term follow-up.

CONCLUSION

STAR prostheses in the United Kingdom have now been largely superseded by newer design TAAs, potentially with improved characteristics and surgical techniques. The long-term survivorship for the STAR prosthesis can provide a benchmark for these later designs of ankle arthroplasty.

Clinical and Radiological Outcomes of Transfibular Total Ankle Arthroplasty

BACKGROUND:

Ankle arthritis is a highly limiting pathology that causes pain and functional limitation with subsequent deterioration of quality of life. With recent advances in surgical instrumentation and techniques, prosthetic replacement of the ankle has proven to be a valid alternative to arthrodesis with comparable outcomes. The purpose of this study was to evaluate clinical and radiological findings in a transfibular total ankle replacement with follow-up of at least 2 years.

METHODS:

This prospective study included 89 patients who underwent transfibular total ankle arthroplasty from May 2013 to February 2016. The mean age was 53.2 ± 13.5 years. All patients were followed for at least 24 months postoperatively with an average follow-up of 42.0 ± 23.5 months. Patients were assessed clinically and radiographically preoperatively and at 6, 12, and 24 months postoperatively.

RESULTS:

At 24 months postoperatively, patients demonstrated statistically significant improvement in the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle Hindfoot Score from 33.8 ± 14.3 to 88.5 ± 6.6 ( P < .001), visual analog scale (VAS) from 80.5 ± 17.0 to 14.1 ± 9.2 ( P < .001), and Short Form-12 Physical and Mental Composite Scores from 29.9 ± 6.7 and 43.3 ± 8.6 to 47.0 ± 7.6 and 53.3 ± 8.1, respectively ( P < .001). In addition, ankle dorsiflexion and plantarflexion improved from 6.2 ± 5.5 and 9.6 ± 5.8 degrees to 24.2 ± 7.9 and 18.1 ± 7.6 degrees, respectively ( P < .001). Radiographically, patients demonstrated maintained neutral alignment of the ankle at 24 months. No patient demonstrated any radiographic evidence of tibial or talar lucency at final follow-up. Seven patients underwent reoperation for removal of symptomatic hardware (6 fibular plates, 1 syndesmotic screw); 2 patients experienced delayed wound healing. The first one was treated with plate removal and flap coverage. The second one required fibular plate removal. One patient developed a postoperative prosthetic infection requiring operative debridement, removal of implants, and placement of an antibiotic spacer.

CONCLUSION:

This study found that transfibular total ankle replacement was a safe and effective option for patients with ankle arthritis resulting in improvements in patient-reported outcomes, range of motion, and radiographic parameters. However, further studies are required to determine the mid- and long-term performance of these implants.

LEVEL OF EVIDENCE:

Level IV, case series.

Management of Posttraumatic Ankle Arthritis: Literature Review

PURPOSE OF REVIEW

Trauma is the principle cause of osteoarthritis in the ankle, which is associated with significant morbidity. This review highlights the current literature for the purpose of bringing the reader up-to-date on the management of posttraumatic ankle arthritis, describing treatment efficacy, indications, contraindications, and complications.

RECENT FINDINGS

Recent studies on osteoarthritis have demonstrated variability among anatomic locations regarding the mechanisms and rates of development for posttraumatic osteoarthritis, which are attributed to newly discovered biological differences intrinsic to each joint. Regarding surgical management of posttraumatic ankle arthritis, osteochondral allograft transplantation of the talus, and supramalleolar osteotomies have demonstrated promising results. Additionally, the outpatient setting was found to be appropriate for managing pain following total ankle arthroplasty, associated with low complication rates and no readmission. Management for posttraumatic ankle arthritis is generally progressive. Initial treatment entails nonpharmacologic options with surgery reserved for posttraumatic ankle arthritis refractory to conservative treatment. Patient demographics and lifestyles should be carefully considered when formulating a management strategy, as outcomes are dependent upon the satisfaction of each set of respective criteria. Ultimately, the management of posttraumatic ankle arthritis should be individualized to satisfy the needs and desires, which are specific to each patient.