Comparison of Treatment Outcomes of Arthrodesis and Two Generations of Ankle Replacement Implants

Outcomes of Total Ankle Replacement

Total ankle replacement (TAR) is an effective operative treatment of end-stage ankle osteoarthritis (OA) in the appropriate patient, conferring improved kinematic function, decreased stress across adjacent joints, and offering equivalent pain relief in comparison to ankle arthrodesis (AA). It is important to consider patient age, weight, coronal tibiotalar deformity, joint line height, and adjacent joint OA to maximize clinical and patient outcomes. Both mobile-bearing and fixed-bearing implants have demonstrated favorable clinical outcomes, marked improvement in patient-reported outcomes, and good survivorship; however, implant survivorship decreases with longer term follow-up, necessitating constant improvement of primary and revision TAR options.

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.

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.

Associations of musculoskeletal dysfunction, time to brake, and patient reported outcomes following lower extremity trauma

INTRODUCTION

Inability to drive a motor vehicle due to lower extremity injury is a major inconvenience. Timing of safe return to driving has not been much studied. Objective measurements such as time to brake (TTB) have been proposed; however, utility and concordance of functional outcome measurements have not been previously evaluated. The purpose of this project is to measure these parameters and to assess for associations with ability to safely return to driving, improving the ability of clinicians to assess for measurements of driving readiness without specifically measuring TTB.

METHODS

A prospective, cohort study of 232 patients with complex lower extremity injuries to the pelvis, acetabulum, hip, femur, knee, tibia, ankle, and foot was performed. Time to brake (TTB) was measured once weightbearing was allowed. Function was assessed by the Musculoskeletal Function Assessment (MFA) questionnaire, and pain, mobility, and physical functions, via patient reported outcome measurement information system (PROMIS) surveys.

RESULTS

Patients with longer TTB had significantly elevated MFA scores indicating increased musculoskeletal dysfunction post-injury. As the MFA score increased by 1 point, TTB increased by 0.013 s (p<0.001). PROMIS metrics were also significantly associated with patients experiencing more pain and worse mobility as TTB increased.

DISCUSSION

Many patients continue to exhibit musculoskeletal dysfunction several months post-treatment for complex lower extremity injuries. Patients with better PROMIS metrics and MFA scores, and shorter TTB are more appropriate to return to driving. Surgeons may be better informed about safe driving ability by considering these measurements.

LEVEL OF EVIDENCE

II.

Ankle arthrodesis or total ankle arthroplasty surgery for end stage ankle arthritis, which is best? A review of the best available evidence

BACKGROUND

End Stage Ankle Arthritis (ESAA) causes pain and dysfunction. It is treated effectively with Total Ankle Arthroplasty (TAA) or Ankle Arthrodesis (AA). Currently there is no consensus on which surgical procedure is superior. This paper will provide a systematic review of all published high-quality studies directly comparing TAA and AA for the surgical treatment of ESAA to determine superiority.

METHODS

A comprehensive literature review of the highest quality studies published that directly compare clinical outcomes of TAA and AA for surgical treatment of ESAA was conducted. Each study was assigned a Level of Evidence (LOE) rating (I-III) and then summarized to assign a grade of recommendation (A-C, I). Superiority was determined for the clinical outcomes of pain, activity, Health Related Quality of Life (HRQL), readmission to hospital, revision surgery and general complications.

RESULTS

There is fair evidence (GOR B) that supports both TAA and AA for the surgical treatment of ESAA. However, TAA trended to be superior for pain relief (GOR B), activity (GOR B), health related quality of life (GOR B) and readmission rate (GOR B) while AA trended to be superior for revision rates (GOR B). Conflicting evidence was presented for general complications (GOR C) CONCLUSION: Due to the lack of level I papers and the findings from the papers reviewed not being consistent, no definitive conclusion on which procedure is better can be made. However, there is enough evidence to provide a basis for which procedure is more effective in each of the outcomes reviewed. This should be considered when deciding on which procedure is best suited for a patient on a case-by-case basis. To allow for a stronger recommendation, further studies-ideally, high-quality level I randomized control trials directly comparing Ankle Arthrodesis and Total Ankle Arthroplasty are needed.

LEVEL OF EVIDENCE

Level III, systematic review.

Total ankle replacement versus ankle fusion for end-stage ankle arthritis: A meta-analysis

PURPOSE

This study aims to systematically review the efficacy and safety of total ankle replacement (TAR) and ankle fusion (AF) as treatment options for end-stage ankle arthritis.

METHODS

A comprehensive literature search was conducted on data from multiple databases, including PubMed, The Cochrane Library, Construction and Building Materials, Embase, Web of Science, and Scopus for RCTs and prospective cohort studies comparing TAR and AF in patients with end-stage ankle arthritis from inception up to June, 2023. Our primary outcomes of interest included patients' clinical function scores and complications. We employed Review Manager 5.4 and Stata/MP 14.0 software for the meta-analysis.

RESULTS

Our analysis incorporated 13 comparative studies, including 11 prospective studies, one pilot RCT, and one RCT. The pooled results revealed no significant difference in postoperative Short Form-36 scores between the TAR and AF groups (MD = -1.19, 95% CI: -3.89 to 1.50, p = .39). However, the postoperative Foot and Ankle Ability Measure scores in the AF group were significantly higher than in the TAR group (MD = 8.30, 95% CI: 1.01-15.60, p = .03). There was no significant difference in postoperative complication rates between the TAR and AF groups (RR = 0.95, 95% CI: 0.59 to 1.54, p = .85).

CONCLUSION

Currently available evidence suggests no significant disparity in postoperative outcomes between TAR and AF. In the short term, TAR demonstrates better clinical scores than AF and lower complication rates. Conversely, in the long term, AF exhibits superior clinical scores and lower complication rates, although this difference is not statistically significant.

Survival and risk assessment in revision arthroplasty of the ankle

Aims

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

Methods

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

Results

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

Conclusion

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

Anatomical principles of ankle denervation - An update

BACKGROUND

Denervation is a surgical option in ankle arthrosis when conservative therapy has failed. Sectioning all joint branches is essential for its success. The locations of the articular branches of the saphenous (Sa), tibial (Ti), sural (Su), superficial (Ps) and deep peroneal (Pp) nerves are specified.

METHODS

In 16 cryopreserved specimens, the courses of the nerves were prepared. Their articular branches were identified, and their respective locations documented by using a new reference system.

RESULTS

The articular branches to the ankle ranged from 5 to 30 cm measured from the foot sole. The Sa should be transected at 22.5 cm, the Su at 20 cm, and the Pp at 15 cm. The Ti should be skeletonized up to 25 cm. Epifascial dissection of the Ps is to be performed below 15 cm.

CONCLUSION

The study specifies the joint branches of the ankle in an intraoperatively reproducible reference system and thus minimizes the required skin incisions.

Prospective Multicenter Study of Salto Talaris Ankle Arthroplasty With Minimum 4-Year Follow-Up

BACKGROUND

Total ankle arthroplasty (TAA) continues to be investigated as a primary treatment for end-stage ankle arthritis. The objective of this study is to report mid- to long-term results of the Salto Talaris TAA using prospectively collected patient-reported outcomes and implant survival rates with 4- to 13-year follow-up.

METHODS

This was a retrospective study of prospectively collected data from 2 multicenter cohort studies from 3 centers. Three hundred fourteen subjects who received a Salto Talaris TAA from 2005 to 2015 were included in the study. Follow-up ranged 4-13 years following index procedure. Outcomes included 36-Item Short Form Health Survey (SF-36) mental and physical component summary scores, pain scores, and adverse events including additional surgeries, revision, or removal of components.

RESULTS

Significant improvements were seen in pain and physical function scores at 2-year follow-up and were generally maintained through most recent follow-up. The survival rate of the prosthesis was >95% (n = 30/32 at >10 years, n = 272/282 at 4.5-10 years). Thirteen patients (4.1%) underwent revision or removal of their prosthesis. Time to revision ranged from 2 months to 6.5 years following the index procedure. Twenty-two patients (7.0%) had additional surgery that did not involve revision or removal of components.

CONCLUSION

Treatment of end-stage ankle arthritis with this implant provided patients with improved pain and functional outcome scores at mid- to long-term follow-up. The significant improvements reported at 2-4 years appeared to endure through the extended follow-up period.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

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 comparative study of modern total ankle replacement and ankle arthrodesis for ankle osteoarthritis at different follow-up times: a systematic review and meta-analysis

PURPOSE

Total ankle replacement (TAR) or ankle arthrodesis (AA) is the main surgical treatment for end-stage ankle osteoarthritis. However, the therapeutic effect of the two surgical procedures at different follow-up times remains controversial. The purpose of this meta-analysis is to compare the short-term, medium-term, and long-term safety and efficiency of the two modern surgical treatments.

METHODS

We conducted a comprehensive search in PubMed, EMBASE, Cochrane library databases, Web of Science, and Scopus. The main results were the patient's reported outcome measure (PROM) score, satisfaction, complications, reoperation, and surgery success rate. Different follow-up times and implant designs were used to evaluate the source of heterogeneity. We used a fixed effects model for meta-analysis and I² statistic for evaluating heterogeneity.

RESULTS

Thirty-seven comparative studies were included. In the short term, TAR significantly improved clinical scores (AOFAS score: WMD = 7.07, 95% Cl: 0.41-13.74, I² = 0.0%; SF-36 PCS score: WMD = 2.40, 95% Cl: 2.22-2.58, I² = 0.0%; SF-36 MCS score: WMD = 0.40, 95% Cl: 0.22-0.57, I² = 0.0%; VAS for pain: WMD =  - 0.50, 95% Cl: - 0.56-0.44, I² = 44.3%) and had the lower incidence of revision (RR = 0.43, 95% CI: 0.23-0.81, I² = 0.0%) and complications (RR = 0.67, 95% Cl: 0.50-0.90, I² = 0.0%). In the medium term, there were still higher improvements in both the clinical scores (SF-36 PCS score: WMD = 1.57, 95% Cl: 1.36-1.78, I² = 20.9%; SF-36 MCS score: WMD = 0.81, 95% Cl: 0.63-0.99, I² = 48.8%) and the patient satisfaction (RR = 1.24, 95% Cl: 1.08-1.41, I² = 12.1%) in the TAR group, but its total complications rate (RR = 1.84, 95% Cl: 1.26-2.68, I² = 14.9%) and revision rate (RR = 1.58, 95% CI: 1.17-2.14, I² = 84.6%) were significantly higher than that of the AA group. In the long term, there was no significant difference in clinical score and satisfaction, and a higher incidence of revision (RR = 2.32, 95% Cl: 1.70-3.16, I² = 0.0%) and complications (RR = 3.18, 95% Cl: 1.69-5.99, I² = 0.0%) was observed in TAR than in AA. The result of the third-generation design subgroup was consistent with that of the above pooled results.

CONCLUSION

TAR had advantages over AA in the short term due to better performance in terms of PROMs, complications, and reoperation rates, but its complications become a disadvantage in the medium term. In the long term, AA seems to be favored because of lower complications and revision rates, although there is no difference in clinical scores.

Total Ankle Replacement: Biomechanics of the Designs, Clinical Outcomes, and Remaining Issues

The present review paper aimed at discussing the current major issues in total ankle replacement, both the technical and biomechanical concepts, and the surgical and clinical concerns. Designers shall target at the same time restoration of natural ankle kinematics and congruity of the artificial surfaces throughout the range of motion. Surgeons are recommended to expand biomechanical knowledge on ankle joint replacement, and provide appropriate training and key factors to make arthroplasty a good alternative to arthrodesis. Moreover, adequate selection of patients and careful rehabilitation are critical. In the future, custom-made prosthesis components and patient-specific instrumentation are major developments for more complex cases.

Incidence of ankle arthrodesis and total ankle replacement between 1997 and 2018: A nationwide registry study in Finland

BACKGROUND

Surgical treatment options for end-stage ankle osteoarthritis (OA) include ankle arthrodesis (AA) and total ankle replacement (TAR). We investigated the national incidence of AA and TAR and assessed trends in the surgical management of ankle OA in Finland between 1997 and 2018.

METHODS

The Finnish Care Register for Health Care was used to calculate the incidence of AA and TAR based on sex and different age groups.

RESULTS

The mean age (SD) of patients was similar, 57.8 (14.3) years for AA and 58.1 (14.0) for TAR. TAR showed a 3-fold increase from 0.3 per 100 000 person-years in 1997 to 0.9 per 100 000 person-years in 2018. The incidence of AA operations decreased during the study period from 4.4 per 100 000 person-years in 1997 to 3.8 per 100 000 person-years in 2018. TAR utilization increased notably at the expense of AA between 2001 and 2004.

CONCLUSION

TAR and AA are both widely used procedures in the treatment of ankle OA, with AA being the favored option for most patients. The incidence of TAR has remained constant for the past 10 years, indicating appropriate treatment indications and utilization.

[Postprimary early elective total arthroplasty in severe ankle fractures]

Treatment of the ankle joint with total ankle arthroplasty (TAA) is an established and safe surgical treatment for osteoarthritis of the ankle. Modern implants have low revision rates and are superior to ankle arthrodesis in terms of patient-reported outcomes. The importance of primary TAA treatment of ankle fractures is unclear. There are currently no studies in the literature on this topic. In view of the increasing number of cases of unstable ankle fractures, especially in older patients and with increasing functional demands also in old age, it is important to consider TAA in the management of these fractures in the future. Clinical studies are necessary to evaluate the treatment of ankle fractures using TAA.

Tibial Component Subsidence in a Total Ankle System Comparing Standard Technique Versus a Hybrid Technique

Total ankle arthroplasty (TAA) is a viable treatment option for end-stage ankle arthritis. However, implant survivorship remains an important consideration. Concerns regarding early component loosening with the low-profile tibial tray utilized by fourth-generation TAA systems have been raised in the literature. We have previously described our preliminary outcomes of a hybrid technique combining a stemmed intramedullary tibial component with a chamfer-cut talar component for TAA. A retrospective study comparing short-term outcomes of the tibial component between a standard fourth-generation TAA system versus our hybrid technique was performed. 46 patients with a minimum of 1-year follow up were included in the analyses. There were 25 subjects in the standard implant cohort utilizing a low-profile tibial tray, and 21 subjects in the hybrid group utilizing a stemmed intramedullary tibial component. No statistically significant difference between the demographics of each group was found. The rate of tibial component subsidence was 8% (n = 2) in the standard implant group, and 0% (n = 0) in the hybrid group, though this did not meet statistical significance (p = .49). Mean time to subsidence was 6 months, and revision rate due to tibial component subsidence was 2.1% (n = 1). Periprosthetic lucency was present on most recent follow-up radiographs in 32% and 9.5% of ankles in the standard and hybrid groups, respectively (p = .08). Despite prior concerns for tibial component subsidence with the standard fourth-generation system, we demonstrated low rates in both implant groups. Additional studies are needed to further explore factors that may predispose patients to early tibial component subsidence and resulting implant failure.

The talar body prosthesis treated end-stage ankle arthritis with talar body deficient: a 6-13 years of follow-up outcomes and 6-year survivorship

INTRODUCTION

Talar body deficient provides a unique challenge for ankle arthritis treatment. We studied the clinical-radiographic outcomes at 6 to 13 years and 6 year prosthesis survivorship of patients treated for ankle arthritis with poor talar body bone stock using a talar body prosthesis (TBP).

MATERIALS AND METHODS

Between 2008 and 2015, we treated 32 consecutive end-stage ankle arthritis patients with talar body deficiency by TBP implantation and fascia interposition. One patient was excluded with a diagnosis of inflammatory arthritis. We assessed visual analogue scale (VAS) of ankle pain, sagittal range of motion, American Orthopaedics Foot and Ankle Society (AOFAS) ankle-hindfoot score, Foot Ankle Ability Measure (FAAM) of activity daily living (ADL), prosthesis tibiotalar surface angle, radiographic prosthesis loosening, adjacent joint arthritis and complication. Pre-operative to last follow-up outcomes (at 6-13 years) were compared. Prosthesis survivorship was analyzed at 6 year follow-up. p < 0.05 was considered a significant difference.

RESULTS

There was statistically significant improvement of median VAS ankle pain, as 8.0 (IQR 1.0) to 1.0 (IQR 2.0), AOFAS ankle-hindfoot score from 48 (IQR 21) to 80 (IQR 7.0), FAAM of ADL from50.0 (28.0) to 88.0 (IQR 15.0), and sagittal ROM from 20^o (IQR 19°) to 33° (IQR 14°), p < 0.05. The median tibiotalar surface angle was statistically significant improved from 85.0° (IQR 8.0°) to 89.0° (IQR 3.0°), p < 0.001. No radiographic prosthesis loosening or adjacent talonavicular-calcaneocuboid joint arthritis. The 6 year prosthesis survivorship was 93.5% (95% CI 84.9-100.0%). End of survivorship was observed in 2 patients due to progressive valgus tilting at 16° and 18°, respectively. No prosthesis was revised.

CONCLUSIONS

TBP implantation with fascia replacing the articular end of distal tibia provided significant better pre- to post-operative clinical outcomes and had 6 year survivorship as 93.5% for the treatment of ankle arthritis with talar body deficient.

LEVEL OF EVIDENCE

IV.

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.

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.

Ankle fusion and replacement gait similar post-surgery, but still exhibit differences versus controls regardless of footwear

Persons with ankle osteoarthritis (AOA) often seek surgical intervention to alleviate pain and restore function; however, recent research has yielded no superior choice between the two primary options: fusion and replacement. One factor yet to be considered is the effect of footwear on biomechanical outcomes. Comparisons of AOA biomechanics to a normative population are also sparse. The objectives of this study were to (1) determine how footwear uniquely affected gait in persons with ankle fusion and replacement and (2) provide context for AOA biomechanics via comparisons to a healthy adult sample. Thirty-four persons with AOA performed overground walking trials barefoot and shod before surgical intervention and then received either an ankle fusion (n = 14) or replacement (n = 20). Two and/or three years post-surgery, patients returned for gait analysis. Nineteen controls performed the same gait procedures during a single study visit. Spatiotemporal variables and peak angles, internal moments, powers, and forces were calculated to quantify gait behavior. Overall, the two surgical groups performed similarly to each other but demonstrated marked differences from controls both pre- and post-surgery. No significant differences were detected when examining the effect of footwear. The motion of the midfoot with respect to the hindfoot and forefoot may be instrumental in gait biomechanics following an ankle fusion or replacement and should be considered in future investigations.

Improvement in Health-Related Quality of Life After Total Ankle Arthroplasty Compares Well With Other Successful Orthopaedic and Nonorthopaedic Procedures

Background. Ankle arthritis is a major cause of disability. Orthopaedic literature suggests improvement in health-related quality of life (HRQOL) after total ankle arthroplasty (TAA). This has not been compared with improvements observed in successful orthopaedic and nonorthopaedic procedures, including anterior cervical discectomy/fusion (ACDF), total knee arthroplasty (TKA), coronary artery bypass grafting (CABG), and orthotopic liver transplant (OLT). We hypothesize that the effects after TAA are comparable to several successful surgical procedures. Methods. 500 consecutive TAA patients were included and grouped with 2 other large series. Short Form-36 (SF36) were collected at standardized intervals. A systematic literature review identified studies comparing preoperative and postoperative SF36 physical (PCS) and mental component summary (MCS) scores. Using meta-analyses, we pooled the data for each procedure to compare with the TAA group. Results. Patients in all cohorts had preoperative SF36 MCS and PCS scores that were significantly lower than that in the general population. Improvements in HRQOL after TAA were not statistically different from improvements reported in PCS and MCS after ACDF, TKA, and OLT. However, improvement in PCS after TAA was better than that observed after CABG. Conclusions. Disability with ankle arthritis is severe. Disability associated with cervical disc disease, knee arthrosis, coronary artery disease, and liver failure is also severe, with surgical intervention providing major improvements in HRQOL postoperatively. The improvement in HRQOL after TAA did not differ statistically from ACDF, TKA, CABG, and OLT. Our investigation suggests that the HRQOL benefits of TAA meet benchmarks set by some of modern medicine's best.Levels of Evidence: Level III: Systematic review.

Evaluating Prospective Patient-Reported Pain and Function Outcomes After Ankle and Hindfoot Arthrodesis

Background:

Hindfoot and ankle fusions are mechanically limiting procedures for patients. However, patient-reported outcomes of these procedures have not been well studied. This study assessed outcomes of hindfoot and ankle fusions by using Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference (PI) Computer Adaptive Tests (CATs).

Methods:

Between 2014 and 2018, 102 patients were prospectively enrolled after presenting to a tertiary care facility for ankle and hindfoot fusions, including tibiotalar, tibiotalocalcaneal, subtalar, and triple arthrodeses. Study participants completed preoperative and 12-month postoperative PF and PI CATs. The differences between mean 12-month postoperative and preoperative PROMIS PF and PI T scores were analyzed with paired t tests. The relationship between the 12-month PF and PI differences for the overall sample and patient factors was examined using multiple regression modeling.

Results:

The sample had mean age of 57.69 years; 48% were male, and 55% were obese. Patients who underwent ankle and hindfoot arthrodesis had statistically significant improvements from preoperative to 12 months postoperative in mean PF (36.26±7.85 vs 39.38±6.46, P = .03) and PI (61.07±7.75 vs 56.62±9.81, P = .02). Triple arthrodesis saw the greatest increases in physical function (▵PF = 7.22±7.31, P = .01) and reductions in pain (▵PI = –9.17±8.31, P = .01), achieving minimal clinically important difference (MCID). Patients who underwent tibiotalar fusion had significant improvement in physical function (▵PF = 4.18±5.68, P = .04) and pain reduction that approached statistical significance (▵PI = –6.24±8.50, P = .09), achieving MCID. Older age (≥60 years ) was associated with greater improvements in PF (β = 0.20, P = .07) and PI (β = –0.29, P = .04). Preoperative PF and PI T scores were significantly associated with the 12-month change in PF and PI T scores, respectively (β = –0.74, P < .01; β = –0.61, P < .01).

Conclusion:

Hindfoot and ankle fusions are procedures with favorable patient outcomes leading to increased physical function and decreased pain at 12 months postoperation relative to preoperation.

Level of Evidence:

Level II, prospective comparative study.

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.

Living With Both a Total Ankle Replacement and an Ankle Fusion: A Qualitative Study From the Patients' Perspective

BACKGROUND

Total ankle replacement (TAR) and ankle fusion are effective treatments for end-stage ankle arthritis. Comparative studies elucidate differences in treatment outcomes; however, the literature lacks evidence demonstrating what outcomes are important to patients. The purpose of this study was to investigate patients' experiences of living with both a TAR and ankle fusion.

METHODS

This research study used qualitative description. Individuals were selected from a cohort of patients with TAR and/or ankle fusion (n = 1254). Eligible patients were English speaking with a TAR and contralateral ankle fusion, and a minimum of 1 year since their most recent ankle reconstruction. Surgeries were performed by a single experienced surgeon, and semistructured interviews were conducted by a single researcher in a private hospital setting or by telephone. Ankle Osteoarthritis Scale (AOS) scores, radiographs, and ancillary surgical procedures were collected to characterize patients. Themes were derived through qualitative data analysis.

RESULTS

Ten adults (8 men, 2 women), ages 59 to 90 years, were included. Average AOS pain and disability scores were similar for both surgeries for most patients. Participants discussed perceptions of each reconstructed ankle. Ankle fusions were considered stable and strong, but also stiff and compromising balance. TARs were considered flexible and more like a "normal ankle," though patients expressed concerns about their TAR "turning" on uneven ground. Individuals applied this knowledge to facilitate movement, particularly during a first step and transitioning between positions. They described the need for careful foot placement and attention to the environment to avoid potential challenges.

CONCLUSION

This study provides insight into the experiences of individuals living with a TAR and ankle fusion. In this unusual but limited group of patients, we found that each ankle reconstruction was generally perceived to have different characteristics, advantages, and disadvantages. Most participants articulated a preference for their TAR. These findings can help clinicians better counsel patients on expectations after TAR and ankle fusion, and improve patient-reported outcome measures by better capturing meaningful outcomes for patients.

LEVEL OF EVIDENCE

Level IV, case series.

Intermediate-Term Outcomes of a Third-Generation, 2-Component Total Ankle Prosthesis

BACKGROUND

Short-term outcomes for the INBONE I and INBONE II tibial stems have been favorable. The INBONE-II talus has been shown to have lower reoperation and failure rates compared to its predecessor at short term follow-up. The purpose of the present study was to assess mid-term outcomes for the third generation, two component total ankle prosthesis at 5 to 9 years follow-up, evaluating both the tibial and talar components.

METHODS

All patients who underwent primary total ankle arthroplasty (TAA) with INBONE-II between July 2010 and July 2014 at a single institution and who were at least 5 years postoperative were included. A total of 15 ankles with a mean follow-up of 85 months (range, 61-113 months) met the criteria. Radiographs were assessed using coronal and sagittal alignment parameters preoperatively, at 6 weeks postoperatively, and at the most recent follow-up. Medical records were reviewed and revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook et al, respectively.

RESULTS

The survivorship of the prosthesis at a mean of 85 months was 93.7%. The coronal and sagittal tibiotalar alignments 6 weeks after surgery were 2.1 degrees (P = .081) and 36% (P = .15), respectively. Maintenance of this alignment was observed during the latest follow-up (P = .684 and P = .837, respectively). One ankle (6.7%) required early component revision, while 4 (26.7%) required a non-implant-related revision. Six complications (2 high grade, 1 intermediate, and 3 low) in 5 ankles (33.3%) were recorded according to the Glazebrook classification system.

CONCLUSION

The present study is the first to report midterm follow-up after TAA with this third-generation, 2-component prothesis. High survivorship, maintenance of correction, and a low incidence of major complications were observed in this small case series. The most common complication overall was lateral gutter impingement, which accounted for the majority of the nonrevisional reoperations.

LEVEL OF EVIDENCE

Level IV, case series.

Comparing 4-Year Changes in Patient-Reported Outcomes Following Ankle Arthroplasty and Arthrodesis

BACKGROUND

The rate of total ankle arthroplasty (TAA) is increasing relative to ankle arthrodesis (AA) for patients seeking surgical treatment for end-stage ankle arthritis. Patients and providers would benefit from a more complete understanding of the rate of improvement, the average length of time to achieve maximal function and minimal pain, and whether there is a greater decline in function or an increase in pain over time following TAA compared with AA. The objectives of this study were to compare treatment changes in overall physical and mental function and ankle-specific function, as well as pain intensity at 48 months after TAA or AA in order to determine if the improvements are sustained.

METHODS

This was a multisite prospective cohort study that included 517 participants (414 TAA and 103 AA) who presented for surgical treatment. Participants were compared 48 months after surgery using the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living and Sports subscales (0 to 100 points), the Short Form-36 (SF-36) Physical and Mental Component Summary (PCS and MCS) scores (0 to 100 points), and pain scores (0 to 10 points).

RESULTS

Both groups achieved significant improvement in the 2 FAAM measures, the SF-36 PCS score, and all of the pain measures at 48 months after surgey (p < 0.001). Mean improvements from baseline in patients undergoing TAA for the FAAM Activities of Daily Living, FAAM Sports, and SF-36 scores were at least 9 points, 8 points, and 3.5 points, respectively, which were higher than in those undergoing AA. Mean improvements in worst and average pain were at least 0.9 point higher in patients undergoing TAA than in those undergoing AA at 12, 24, and 36 months. These differences were attenuated by 48 months. For both treatments, all improvements from baseline to 24 months had been maintained at 48 months.

CONCLUSIONS

When both procedures are performed by the same group of surgeons, patients who undergo TAA or AA for end-stage ankle arthritis have significant improvement in overall function, ankle-specific function, and pain at 48 months after surgery, with better functional improvement in the TAA group.

LEVEL OF EVIDENCE

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

Comparison of Preoperative Bone Density in Patients With and Without Periprosthetic Osteolysis Following Total Ankle Arthroplasty

BACKGROUND

Modern total ankle arthroplasty (TAA) prostheses are uncemented press-fit designs whose stability is dependent on bone ingrowth. Preoperative insufficient bone density reduces initial local stability at the bone-implant interface, and we hypothesized that this may play a role in periprosthetic osteolysis. We aimed to investigate the preoperative bone density of the distal tibia and talus and compare these in patients with and without osteolysis.

METHODS

We enrolled 209 patients (218 ankles) who underwent primary TAA using the HINTEGRA prosthesis. The overall mean follow-up duration was 66 (range, 24-161) months. The patients were allocated into 2 groups according to the presence of periprosthetic osteolysis: the osteolysis group (64 patients, 65 ankles) and nonosteolysis group (145 patients, 153 ankles). Between the 2 groups, we investigated and compared the radiographic outcomes, including the Hounsfield unit (HU) value around the ankle joint and the coronal plane alignment.

RESULTS

HU values of the tibia and talus measured at 5 mm from the reference points were higher than those at 10 mm in each group. However, comparing the osteolysis and nonosteolysis groups, we found no significant intergroup difference in HU value at every measured level in the tibia and talus (P > .05). Concerning the coronal plane alignment, there were no significant between-group differences in the tibiotalar and talar tilt angles (P > .05).

CONCLUSION

Patients with osteolysis showed similar preoperative bone density of the distal tibia and talus compared with patients without osteolysis. Our results suggest that low bone density around the ankle joint may not be associated with increased development of osteolysis.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

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 Gait and Stair Ascent After Total Ankle Arthroplasty and Ankle Arthrodesis

BACKGROUND

Ankle arthrodesis has historically been the standard of care for end-stage ankle arthritis; however, total ankle arthroplasty (TAA) is considered a reliable alternative. Our objective was to compare 3-dimensional foot and ankle kinetics and kinematics and determine the ankle power that is generated during level walking and stair ascent between TAA and ankle arthrodesis patients.

METHODS

Ten patients who underwent TAA with a modern fixed-bearing ankle prosthesis and 10 patients who previously underwent ankle arthrodesis were recruited. Patients were matched for age, sex, body mass index, time from surgery, and preoperative diagnosis. A minimum of 2-year follow-up was required. Patients completed instrumented 3D motion analysis while walking over level ground and during stair ascent. Between-group differences were assessed with a 2-tailed Mann-Whitney exact test for 2 independent samples.

RESULTS

Sagittal ankle range of motion (ROM) was significantly higher in the TAA group (21.1 vs 14.7 degrees, P = .003) during level walking. In addition, forefoot-tibia motion (25.3±5.9 degrees vs 18.6±5.1 degrees, P = .015) and hindfoot-tibia motion (15.4±3.2 degrees vs 12.2±2.5 degrees, P = .022) were significantly greater in the TAA group. During stair ascent, sagittal ankle ROM (25 vs 17.1 degrees, P = .026), forefoot-tibia motion (27.6 vs 19.6 degrees, P = .017), and hindfoot-tibia motion (16.8 vs 12 degrees, P = .012) was greater.

CONCLUSION

There were significant differences during level walking and stair ascent between patients with TAA and ankle arthrodesis. TAA patients generated greater peak plantarflexion power and sagittal motion within the foot and ankle compared to patients with an ankle arthrodesis. Further investigation should continue to assess biomechanical differences in the foot and ankle during additional activities of daily living.

LEVEL OF EVIDENCE

Level III, comparative study.

Adverse events related to total ankle replacement devices: an analysis of reports to the United States Food and Drug Administration

Background

The published outcomes of total ankle replacement (TAR) implants came from limited institutions creating observational bias. For broader perspective, we queried the Food and Drug Administration’s (FDA) Manufacturer and User Facility Device Experience (MAUDE) voluntary database to explore complications reported outside published literature.

Methods

The database was reviewed retrospectively between November 2011 and April 2019 using two product codes assigned to six TAR devices.

Results

Among 648 relevant reports available in the database, common complications were aseptic loosening (19.3%), infection (18.2%), and alignment/mechanical issues (16.5%). Others included instrument/instrumentation complications, impingement, polyethylene problems, fractures, avascular necrosis of talus (AVN), and packaging issues.

Conclusion

MAUDE database revealed various patterns of device-related malfunctions that have been under-reported in published data. Despite inconsistency in the available reports, it provided opportunities for improvements in quality control, device design, and ultimately patient safety. Database would be further strengthened by more robust reporting mechanism or mandatory reporting of device-related complications.

Mobile Anatomical Total Ankle Arthroplasty-Improvement of Talus Recentralization

Introduction: Total ankle arthroplasty (TAA) is becoming a more frequent treatment option for end-stage ankle osteoarthritis (OA) as outcomes measures are improving. However, there is concern that malalignment of TAA can result in premature failure of the implant. One of the malalignment issues is the talar sagittal malposition. However, a consensus on the significance of the sagittal translation of the talus in TAA is yet to be established. The aim of this study was, therefore, to clarify whether talus OA subluxation is normalized after the implantation of a mobile TAA. Methods: Forty-nine consecutive patients with symptomatic end-stage ankle OA underwent 50 cementless three-component mobile-bearing VANTAGE TAA with 21 right ankles (42%) and 29 left ankles (58%). Clinical and radiographic outcomes were assessed: Clinical variables: American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score (0–100), visual analogue scale (VAS, 0–10), and ankle range of motion (ROM). Radiological variables: medial distal tibial articular angle (mDTAA), anterior distal tibial articular angle (aDTAA) and lateral talar station (LTS). Results: The clinical results showed the mean improvement in AOFAS hindfoot score from 42.12 ± SE 2.42 (Range: 9–72) preoperatively, to 96.02 ± SE 0.82 (Range: 78–100) at a mean follow-up of 12 months, with a highly statistically significant difference (p < 0.00001). Pain score (VAS) was 6.70 ± SE 0.28 (Range 0–10) preoperatively, and 0.26 ± SE 0.12 (Range: 0–3) at 12-month follow-up, with a highly statistically significant difference (p < 0.00001). ROM measurements preoperatively showed a mean of 22.55° ± SE 1.51° (Range: 0–50°), which showed a statistically significant improvement (p < 0.0001) to 45.43° ± SE 1.56° (Range: 25–60°) 12 months postoperatively. The radiological analyses revealed the following results: On the coronal view, the mDTAA preoperatively was 88.61 ± SE 0.70 (Range: 78.15–101.10), which improved to 89.46 ± SE 0.40 (Range: 81.95–95.80) at 12 months (not statistically significant—p = 0.94). On the sagittal view, the preoperative values of the aDTAA showed 82.66 ± SE 0.84 (Range: 70.35–107.47), which improved to 88.98 ± SE 0.47 (Range: 82.83–96.32) at 12 months postoperatively, with a highly statistically significant difference between preoperative and 12-months values (p < 0.00001). The mean LTS values for all patients were 3.95 mm ± SE 0.78 (Range: −11.52 to 13.89) preoperatively and 1.14 mm ± SE 0.63 (Range: −10.76 to 11.75) at 12 months, with a statistically significant difference between preoperative and 12-month follow-up (p = 0.01). The review of the radiological TAA osteointegration at 12 months showed no cases of loosening of the implanted TAAs. Two cases (4%) showed a radiolucency and one case (2%) a cyst on the tibial component; no cases had a change on the talar component. No TAA complication/revision surgeries were documented. Conclusion: In the present study, the lateral talar station of anteriorly subluxated ankles showed a significant improvement, i.e., physiological centralization of the talus, in the postoperative period when a mobile-bearing TAA was performed. The anterior/posterior congruency between the talar component and the mobile polyethylene insert of the mobile-bearing VANTAGE TAA allows the sagittal translation of the talus relative to the flat tibial component, reducing the prosthesis strain and failure.

Total ankle arthroplasty

For end-stage ankle arthritis, either arthrodesis or total ankle arthroplasty is a available surgical option. With the failure of earlier generation of arthroplasty, arthrodesis has been the gold standard. However, there are some considerable weaknesses of the arthrodesis. Current total ankle arthroplasty is presently an effective surgical treatment for endstage ankle arthritis with much improvement. The goals of surgery are to decrease pain, preserve range of motion, and eventually improve the patient’s quality of life. Recent literatures on total ankle arthroplasty havs shown successful long-term clinical results due to the innovation of second-generation implants, including more anatomic concepts and designs. For successful outcomes, a thorough evaluation of the entire lower limb alignment, deformities of the foot and ankle, and proper selection of patients are very important. Nevertheless, complications, such as wound problems, osteolysis, gutter pain or impingement, infection, loosening, and others, may occur. In this review, we provide a summary of the current research on total ankle arthroplasty.

Does Coronal Plane Malalignment of the Tibial Insert in Total Ankle Arthroplasty Alter Distal Foot Bone Mechanics? A Cadaveric Gait Study

BACKGROUND

Total ankle arthroplasty (TAA) is becoming a more prevalent treatment for end-stage ankle arthritis. However, the effects of malalignment on TAA remain poorly understood.

QUESTIONS/PURPOSES

The purpose of this study was to quantify the mechanical effects of coronal plane malalignment of the tibial insert in TAA using cadaveric gait simulation. Specifically, we asked, is there a change in (1) ankle joint congruency, (2) kinematic joint position, (3) kinematic ROM, (4) peak plantar pressure, and (5) center of pressure with varus and valgus malalignment?

METHODS

A modified TAA was implanted into seven cadaveric foot specimens. Wedges were used to simulate coronal plane malalignment of the tibial insert. The degree of malalignment (tibial insert angle [TIA] and talar component angle [TCA]) was quantified radiographically for neutral and 5°, 10°, and 15° varus and valgus wedges. Dynamic walking at 1/6 of physiological speed was simulated using a robotic gait simulator. A motion capture system was used to measure foot kinematics, and a pressure mat was used to measure plantar pressure. Joint congruency was quantified as the difference between TIA and TCA. Continuous joint position, joint ROM, peak plantar pressure, and center of pressure for varus and valgus malalignment compared with neutral alignment were estimated using linear mixed effects regression. Pairwise comparisons between malalignment conditions and neutral were considered significant if both the omnibus test for the overall association between outcome and malalignment and the individual pairwise comparison (adjusted for multiple comparisons within a given outcome) had p ≤ 0.05.

RESULTS

Descriptively, the TIA and TCA were both less pronounced than the wedge angle and component incongruence was seen (R = 0.65; p < 0.001). Varus malalignment of the tibial insert shifted the tibiotalar joint into varus and internally rotated the joint. The tibiotalar joint's ROM slightly increased as the TIA shifted into varus (1.3 ± 0.7° [mean ± SD] [95% confidence interval -0.7 to 3.4]; p = 0.03), and the first metatarsophalangeal joint's ROM decreased as the TIA shifted into varus (-1.9 ± 0.9° [95% CI -5.6 to 1.7]; p = 0.007). In the sagittal plane, the naviculocuneiform joint's ROM slightly decreased as the TIA shifted into varus (-0.9 ± 0.4° [95% CI -2.1 to 0.3]; p = 0.017). Hallux pressure increased as the TIA became more valgus (59 ± 50 kPa [95% CI -88 to 207]; p = 0.006). The peak plantar pressure slightly decreased in the third and fourth metatarsals as the TIA shifted into valgus (-15 ± 17° [95% CI -65 to 37]; p = 0.03 and -8 ± 4° [95% CI -17 to 1]; p = 0.048, respectively). The fifth metatarsal's pressure slightly decreased as the TIA shifted into valgus (-18 ± 12 kPa [95% CI -51 to 15]) or varus (-7 ± 18 kPa [95% CI -58 to 45]; p = 0.002). All comparisons were made to the neutral condition.

CONCLUSIONS

In this cadaver study, coronal plane malalignment in TAA altered foot kinematics and plantar pressure. In general, varus TAA malalignment led to varus shift and internal rotation of the tibiotalar joint, a slight increase in the tibiotalar ROM, and a slight decrease in the first metatarsophalangeal ROM, while a valgus TAA malalignment was manifested primarily through increased hallux pressure with a slight off-loading of the third and fourth metatarsals.

CLINICAL RELEVANCE

This study may increase our understanding of the biomechanical processes that underlie the unfavorable clinical outcomes (such as, poor patient-reported outcomes or implant loosening) that have been associated with coronal plane malalignment of the tibial component in TAA.

COMPARING OUTCOMES OF THE ANKLE ARTHRODESIS BY USING TWO DIFFERENT MATERIALS VIA A TRANSFIBULAR APPROACH

Objective:

To compare clinical and radiologic results and complications of patients who underwent arthrodesis using a transfibular approach with either a cannulated screw or an anterior fusion plate.

Methods:

Patients who underwent ankle arthrodesis were divided into two groups according to the used materials: 6.5 mm cannulated screw (A) and anterior fusion plate (B). The clinical scores were compared between groups. The radiologic results were then assessed by union time. The results were statistically analyzed using SPSS 20.

Results:

There was no significant difference between both groups in the American Orthopedic Foot & Ankle Society (AOFAS) score (p = 0.75), and in the visual analog scale (p = 0.42). In group B, two cases included wound infection at the surgical site. In tt A, the mean union time was 10.5 ± 2.3 weeks. In group B, it was 7.8 ± 1.3. There was a statistically significant difference (p = 0.007) between union time in both groups.

Conclusion:

Anterior fusion plate is an effective method for shorter union time, but the surgeon should be careful with the surgical wound at the skin incision site in the lesion of the distal tibia. Level of Evidence III, Retrospective comparative study.

Management of Ankle Arthritis After Severe Ankle Trauma

OBJECTIVES

There are still unanswered questions about the best treatment options for ankle arthritis after severe lower leg trauma. This study compared results in outcomes and complications for 3 groups.

DESIGN

Retrospective cohort study case-control study.

SETTING

Single institution.

PATIENTS

Three groups of 100 surgeries.

INTERVENTION

Patients underwent an ankle fusion using anterior plate, total ankle arthroplasty (TAA) for primary osteoarthritis (OA), or a TAA for post-traumatic arthritis (PTA).

MAIN OUTCOME MEASUREMENTS

Veterans Rand 12-Item Health Survey (VR-12), Ankle Osteoarthritis Scale, Visual Analog Pain Scale, and the American Orthopaedic Foot and Ankle Society Hindfoot score were collected preoperatively and at subsequent postoperative appointments. A patient satisfaction survey was also distributed to each patient postoperatively.

RESULTS

Although all scores improved from preoperative to latest postoperative, the total ankle for PTA consistently resulted in the best postoperative outcomes. Patient satisfaction survey indicated 26% of fusion, 55% of TAA-OA, and 63% of TAA-PTA experienced very good to excellent pain relief. The overall satisfaction was found to be 92.5% for the TAA-PTA patients, 90.5% for the TAA-OA patients, and 84% for the fusion patients. Revision surgeries included 2 from the TAA-OA group, 2 from the TAA-PTA group, and 1 fusion patient.

CONCLUSIONS

Results of comparing 3 groups who underwent an ankle fusion or a TAA demonstrate improvement in pain (P < 0.001), physical quality of life (P < 0.001), and activity (P < 0.001) and resulted in a high level of patient satisfaction.

LEVEL OF EVIDENCE

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

Autologous Osteochondral Graft for Early Posttraumatic Arthritis of Tibiotalar Joints After Comminuted Pilon Fractures in Young Patients

BACKGROUND

Posttraumatic arthritis of tibiotalar joints after AO/OTA type C3 pilon fractures, especially in young patients with a significant osteochondral defect in the tibial plafond joint surface, is a challenging situation. We report a joint-preserving technique using autologous osteochondral graft in combination with ankle distraction and supramalleolar osteotomy (SMOT), if necessary, to improve its outcome.

METHODS

Seventeen patients with an average age of 32.1 years with Takakura grade 1 to 3A posttraumatic arthritis of the tibiotalar joint after AO/OTA type C3 pilon fractures received osteochondral autograft transplantation, ankle distraction, and SMOT, when supramalleolar malalignment was present, between February 2010 and November 2015. The visual analog scale (VAS), Short-Form 36 (SF-36) score, American Orthopaedic Foot & Ankle Society (AOFAS) score, and ankle range of motion were used for outcome analysis. Radiographic assessment of any SMOT and the apparent joint space was performed. Fourteen patients were followed for an average of 18 months.

RESULTS

The VAS, SF-36, and AOFAS scores as well as the ankle range of motion all improved significantly at the last follow-up after the surgery (P < .01). No deep surgical site infection, donor site complication, nonunion, osteochondral block loosening, or resorption was noted. No secondary arthrodesis was needed at the end of follow-up.

CONCLUSION

Autologous osteochondral graft transplantation in combination with ankle distraction and SMOT was a promising joint-preserving technique for early posttraumatic arthritis of tibiotalar joint after severe pilon fractures in young patients.

LEVEL OF EVIDENCE

Level IV, case series.

Outcomes of Total Ankle Arthroplasty in Ankles with >20° of Coronal Plane Deformity

BACKGROUND

A preoperative severe coronal plane deformity of >20° has been considered a contraindication for total ankle arthroplasty. We aimed to evaluate whether outcomes of total ankle arthroplasty in ankles with severe coronal plane deformity (20° to 35° of varus or valgus) are comparable with those with moderate deformity (5° to 15° of varus or valgus).

METHODS

A total of 148 consecutive ankles (142 patients) that underwent primary total ankle arthroplasty using the HINTEGRA prosthesis were included. The overall mean follow-up duration was 74 months (range, 24 to 160 months). We divided all patients into 2 groups according to the preoperative coronal plane tibiotalar angle: the severe group (36 patients, 41 ankles) and the moderate group (106 patients, 107 ankles). Clinical and radiographic outcomes were analyzed for intergroup differences, and multivariable regression was used to adjust for baseline characteristics. Patients in each group showed similar characteristics in mean age, sex, mean body mass index, and median follow-up duration.

RESULTS

At a mean follow-up of 74 months, we found no significant intergroup difference in the Ankle Osteoarthritis Scale pain and disability score, American Orthopaedic Foot & Ankle Society ankle-hindfoot score, Short Form-36 Physical Component Summary score, visual analog scale pain score, or ankle range of motion (p > 0.05). However, the final tibiotalar angle, talar tilt angle, and number of outliers were greater in the severe group (p < 0.05). Complication rates did not show a significant difference between the 2 groups (p > 0.05). The overall survival probability of the implant was 91.3% (92.3% in the severe group and 90.7% in the moderate group) (p = 0.354).

CONCLUSIONS

Total ankle arthroplasty in ankles with preoperative severe coronal plane deformity showed satisfactory and comparable clinical outcomes without increasing complication rates relative to those with moderate deformity in the intermediate-term follow-up. Our results suggested that total ankle arthroplasty may be considered in ankles with deformity of >20°.

LEVEL OF EVIDENCE

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

Assessing the Ankle Joint Line Level Before and After Total Ankle Arthroplasty With the "Joint Line Height Ratio"

BACKGROUND

Restoring the joint line is an important principle in total knee arthroplasty. However, the effect of joint line level on patient outcomes after total ankle arthroplasty (TAA) remains unclear, as there is no established method for measuring ankle joint level in TAA. The objective of this study was to develop a reliable radiographic ankle joint line measurement method and to compare ankle joint line level measured pre-TAA, post-TAA, and in nonarthritic ankles.

METHODS

A total of 112 radiographic sets were analyzed. Each set included weightbearing anteroposterior radiographs of the operative ankle taken preoperatively, 1-year postoperatively, and of the contralateral ankle. Measurements of vertical intermalleolar distance (VIMD) and vertical joint line distance (VJLD) at pre-TAA, post-TAA, and of the contralateral ankle were recorded by 2 authors on 2 separate occasions. The ratio of VJLD to VIMD was defined as the joint line height ratio (JLHR). Reliability of measurements and correlation between VIMD and VJLD were assessed. Pre-TAA, nonarthritic contralateral ankle, and post-TAA JLHR were compared and considered significantly different if P <.05.

RESULTS

The inter- and intrarater reliability of radiographic measurements was excellent (r > 0.9). There were strong positive correlations of VIMD and VJLD, r = 0.809 (pre-TAA)/0.756 (post-TAA), P < .001. Mean (SD) pre-TAA, nonarthritic contralateral ankle, and post-TAA JLHRs were 1.54 (0.31), 1.39 (0.26), and 1.62 (0.49), respectively. Pre- and post-TAA JLHRs were significantly higher compared to the nonarthritic contralateral ankle (P < .05). JHLR was not significantly different between pre- and post-TAA (P = .15).

CONCLUSION

The JLHR was reliable and could be a clinically applicable method for assessing ankle joint line level in patients undergoing TAA. End-stage ankle arthritis demonstrated elevated joint line level compared with nonarthritic ankles, and the joint line level post-TAA remained elevated compared with nonarthritic ankles. Further studies are needed to understand the effect of joint line elevation on clinical outcomes after TAA.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Effectiveness and Safety of Ankle Arthrodesis Versus Arthroplasty: A Prospective Multicenter Study

BACKGROUND

Newer designs and techniques of total ankle arthroplasty (TAA) have challenged the assumption of ankle arthrodesis (AA) as the primary treatment for end-stage ankle arthritis. The objective of this study was to compare physical and mental function, ankle-specific function, pain intensity, and rates of revision surgery and minor complications between these 2 procedures and to explore heterogeneous treatment effects due to age, body mass index (BMI), patient sex, comorbidities, and employment on patients treated by 1 of these 2 methods.

METHODS

This was a multisite prospective cohort study comparing outcomes of surgical treatment of ankle arthritis. Subjects who presented after nonoperative management had failed received either TAA or AA using standard-of-treatment care and rehabilitation. Outcomes included the Foot and Ankle Ability Measure (FAAM), Short Form-36 (SF-36) Physical and Mental Component Summary (PCS and MCS) scores, pain, ankle-related adverse events, and treatment success.

RESULTS

Five hundred and seventeen participants underwent surgery and completed a baseline assessment. At 24 months, the mean improvement in FAAM activities of daily living (ADL) and SF-36 PCS scores was significantly greater in the TAA group than in the AA group, with a difference between groups of 9 points (95% confidence interval [CI] = 3, 15) and 4 points (95% CI = 1, 7), respectively. The crude incidence risks of revision surgery and complications were greater in the AA group; however, these differences were no longer significant after adjusting for age, sex, BMI, and Functional Comorbidity Index (FCI). The treatment success rate was greater after TAA than after AA for those with an FCI of 4 (80% versus 62%) and not fully employed (81% versus 58%) but similar for those with an FCI score of 2 (81% versus 77%) and full-time employment (79% versus 78%).

CONCLUSIONS

At 2-year follow-up, both AA and TAA were effective. Improvement in several patient-reported outcomes was greater after TAA than after AA, without a significant difference in the rates of revision surgery and complications.

LEVEL OF EVIDENCE

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

Step Activity After Surgical Treatment of Ankle Arthritis

BACKGROUND

Ambulatory activity is reduced in patients with ankle arthritis. In this study, we measured step activity over time in 2 treatment groups and secondarily compared step activity with results of patient-reported outcome measures (PROMs).

METHODS

Patients who were treated with either ankle arthrodesis or ankle arthroplasty wore a step activity monitor preoperatively and at 6, 12, 24, and 36 months postoperatively. Changes from preoperative baseline in total steps per day and per-day metrics of low, medium, and high-activity step counts were measured in both treatment groups. Step activity was compared with each subject's PROM scores as reported on the Musculoskeletal Function Assessment (MFA) and the Short Form-36 (SF-36) physical function and bodily pain subscales.

RESULTS

Of the 3 activity levels, combined group high-activity step counts showed the greatest increase (mean of 278 steps [95% confidence interval (CI), 150 to 407 steps], a 46% improvement from preoperatively). At 6 months, the mean high-activity step improvement for the arthroplasty group was 194 steps compared with a mean decline of 44 steps for the arthrodesis group (mean 238-step difference [95% CI, -60 to 536 steps]). By 36 months postoperatively, the greater improvement in high-activity steps for the arthroplasty versus the arthrodesis group was no longer present. There were no significant pairwise differences in improvement based on surgical treatment method at any individual follow-up time point. For a within-patient increase of 1,000 total steps, there was a mean change in the MFA, SF-36 physical function, and SF-36 bodily pain scores of -1.8 (95% CI, -2.4 to -1.2), 3.8 (95% CI, 2.8 to 4.8), and 2.8 (95% CI, 1.8 to 3.9), respectively (p < 0.0001 for all associations). There was no evidence that the association differed by study visit, or by study visit and surgical procedure interaction (p > 0.10).

CONCLUSIONS

Surgical treatment of ankle arthritis significantly improves ambulatory activity, with greater change occurring at high activity levels. Improvement may occur more quickly following arthroplasty than arthrodesis, but at 3 years, we detected no significant difference between the 2 procedures. Step counts, while associated with PROMs, do not parallel them, and thus may be a useful supplementary measure, particularly in longitudinal studies.

LEVEL OF EVIDENCE

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

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.

Total ankle arthroplasty incorporating a total talar prosthesis

Aims

Total ankle arthroplasty (TAA) has become the most reliable surgical solution for patients with end-stage arthritis of the ankle. Aseptic loosening of the talar component is the most common complication. A custom-made artificial talus can be used as the talar component in a combined TAA for patients with poor bone stock of the talus. The purpose of this study was to investigate the functional and clinical outcomes of combined TAA.

Patients and Methods

Ten patients (two men, eight women; ten ankles) treated using a combined TAA between 2009 and 2013 were matched for age, gender, and length of follow-up with 12 patients (one man, 11 women; 12 ankles) who underwent a standard TAA. All had end-stage arthritis of the ankle. The combined TAA features a tibial component of the TNK ankle (Kyocera, Kyoto, Japan) and an alumina ceramic artificial talus (Kyocera), designed using individualized CT data. The mean age at the time of surgery in the combined TAA and standard TAA groups was 71 years (61 to 82) and 75 years (62 to 82), respectively. The mean follow-up was 58 months (43 to 81) and 64 months (48 to 88), respectively. The outcome was assessed using the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale, the Ankle Osteoarthritis Scale (AOS), and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q).

Results

The mean preoperative JSSF score of the combined TAA and standard TAA groups was 44 (sd 11) and 49 (sd 10), respectively. The mean postoperative JSSF scores were 89 (sd 6.1) and 72 (sd 15), respectively. The mean postoperative JSSF score of the combined TAA group was significantly higher (p = 0.0034). The mean preoperative AOS scores for pain and function in the combined TAA and standard TAA groups were 5.8 (sd 3.3) and 5.5 (sd 3.1), and 8.6 (sd 1.3), and 7.1 (sd 2.9), respectively. The mean postoperative AOS scores of pain and function were 2.5 (sd 2.5) and 2.2 (sd 1.9), and 2.5 (sd 3.3) and 3.4 (sd 2.9), respectively. There were no significant differences between the two groups in terms of postoperative AOS scores. The mean postoperative SAFE-Q scores were: for pain, 76 (sd 23) and 70 (sd 23); for physical function, 66 (sd 25) and 55 (sd 27); for social function, 73 (sd 35) and 62 (sd 34); for shoe-related, 73 (sd 19) and 65 (sd 26); and for general health, 78 (sd 28) and 67 (sd 29), respectively. There were no significant differences between the two groups in terms of postoperative SAFE-Q scores.

Conclusion

Combined TAA resulted in better clinical results than standard TAA. Cite this article: Bone Joint J 2019;101-B:443–446.

Revision Surgery for Metal Component Failure in Total Ankle Arthroplasty

Background:

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

Methods:

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

Results:

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

Conclusions:

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

Level of Evidence:

Level III, therapeutic.

Analysis of Failed Ankle Arthroplasty Components

BACKGROUND:

Although advances in joint-replacement technology have made total ankle arthroplasty a viable treatment for end-stage arthritis, revision rates for ankle replacements are higher than in hip or knee replacements. The questions asked in this study were what can retrieved ankle devices demonstrate about ankle arthroplasty failures and how can understanding the causes of these failures inform clinical decisions for current and future ankle arthroplasty patients?

METHODS:

An IRB-approved retrieval laboratory received retrieved components and surgeon-supplied reason for revision from 70 total-ankles (7 designs, including 5 currently marketed designs) from 2002 to 2018. These retrievals were rated for clinical wear and damage. Metal components were rated by method and effectiveness of fixation. Polyethylene inserts received by the laboratory 6 months or less after retrieval (n = 45) were analyzed for oxidation using Fourier transform infrared spectroscopy. Statistical analysis was performed using IBM SPSS, version 22.

RESULTS:

The ankle implants were retrieved most commonly for loosening and polyethylene fracture. Loosening occurred more frequently in fixed-bearing designs (n = 18) than in the mobile-bearing designs (n = 4) and after shorter in vivo time (mean in vivo time to retrieval for loosening: fixed bearing 3.2 ± 2.1 years, mobile bearing 9.7 ± 4.5 years). Gamma-sterilized ankle inserts oxidized at a higher rate than non-gamma (EtO or gas-plasma) sterilized ankle inserts (gamma 0.29 ± 0.22/y, non-gamma 0.07 ± 0.05/y, mean difference=0.215, 95% CI 0.128-0.303, P < .001). The presence of clinical fatigue (cracking and/or delamination) of the polyethylene insert correlated with measured oxidation (Spearman rho = 0.685, P < .001). Nine inserts, all gamma-sterilized, fractured in vivo.

CONCLUSIONS:

This study suggests that loosening could be more of a problem in fixed-bearing devices than in mobile bearing devices. Gamma-sterilized polyethylene inserts were found to suffer fatigue damage or fracture in vivo, resulting in the need for revision. Retrieval analysis can provide insight into implant-related reasons for revision, with the goal of understanding the implant-related causes of these failures, informing future ankle design and clinical decisions for current and future ankle arthroplasty patients.

LEVEL OF EVIDENCE:

Level III, comparative series.

Comparison of 25 ankle arthrodeses and 25 replacements at 67 months' follow-up

INTRODUCTION

In the treatment of osteoarthritis of the ankle, controversy persists between advocates of arthrodesis and of joint replacement.

HYPOTHESIS

Results of total ankle replacement (TAR) are equivalent to those of ankle arthrodesis (AA).

MATERIAL AND METHODS

A single-center continuous retrospective series included 50 patients (25 TAR, 25 AA) operated on by a single surgeon. TAR used the standard Salto^® mobile-bearing prosthesis, and arthrodesis used screws or plates. Results were assessed clinically on AOFAS score, visual analog scale (VAS) and satisfaction questionnaire, and radiologically on X-ray and CT. Survivorship in the 2 procedures was estimated on the Kaplan Meier method.

RESULTS

At a mean 67 months' follow-up (range, 40-105 months), mean AOFAS and VAS scores were significantly better in the AA group (74.1 and 1.9, respectively) than in the TAR group (67 and 3.5, respectively) (p<0.001). In the AA group, 80% of patients were satisfied or very satisfied, compared to 64% after TAR. Five-year survival without revision for non-union (AA) or implant removal (TAR) was similar between groups: AA, 96%; TAR, 90% (p=0.72). In contrast, survival with no revision procedures was significantly better with AA (96%) than TAR (75%) (p=0.03).

DISCUSSION

At 5 years, surgical revision rates were significantly greater than after standard Salto^® mobile-bearing TAR than for arthrodesis, notably due to onset of cysts; we therefore decided to abandon this implant.

LEVEL OF EVIDENCE

IV, comparative retrospective study.

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

BACKGROUND:

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

METHODS:

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

RESULTS:

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

CONCLUSIONS:

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

LEVELS OF EVIDENCE:

Therapeutic Level III, comparative series.

Revision and Salvage Management: Proceedings of the International Consensus Meeting on Cartilage Repair of the Ankle

BACKGROUND

The evidence supporting best practice guidelines in the field of cartilage repair of the ankle are based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article was to report on the consensus statements on "Revision and Salvage Management" developed at the 2017 International Consensus Meeting on Cartilage Repair of the Ankle.

METHODS

Seventy-five international experts in cartilage repair of the ankle representing 25 countries and 1 territory were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within 11 working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed and the available evidence for each statement was graded. Discussion and debate occurred in cases where statements were not agreed on in unanimous fashion within the working groups. A final vote was then held, and the strength of consensus was characterized as follows: consensus, 51% to 74%; strong consensus, 75% to 99%; unanimous, 100%.

RESULTS

A total of 8 statements on revision and salvage management reached consensus during the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. One achieved unanimous support and 7 reached strong consensus (greater than 75% agreement). All statements reached at least 85% agreement.

CONCLUSIONS

This international consensus derived from leaders in the field will assist clinicians with revision and salvage management in the cartilage repair of the ankle.