Comparison of gait after total ankle arthroplasty and ankle arthrodesis

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.

Total ankle arthroplasty improves discrete and continuous stance phase gait symmetry

BACKGROUND

Total ankle arthroplasty (TAA) is used to treat symptomatic end-stage ankle arthritis (AA). However, little is known about TAA's effects on gait symmetry.

RESEARCH QUESTION

Determine if symmetry changes from before surgery through two years following TAA utilizing the normalized symmetry index (NSI) and statistical parametric mapping (SPM).

METHODS

141 patients with end-stage unilateral AA were evaluated from a previously collected prospective database, where each participant was tested within two weeks of surgery (Pre-Op), one year and two years following TAA. Walking speed, hip extension angle and moment, hip flexion angle, ankle plantarflexion angle and moment, ankle dorsiflexion angle, weight acceptance (GRF1), and propulsive (GRF2) vertical ground reaction forces were calculated for each limb. Gait symmetry was assessed using the NSI. A linear mixed effects model with a single response for each gait symmetry variable was used to examine the fixed effect of follow-up time (Pre-Op, Post-1 yr, Post-2 yr) and the random effect of participant with gait speed as a covariate in the model. A one-dimensional repeated measures analysis of variance (ANOVA) statistical parameter mapping (SPM) was completed to examine differences in the time-series NSI to determine regions of significant differences between follow-up times.

RESULTS

Relative to Pre-Op values, GRF1, and GRF2 showed increased symmetry for discrete metrics and the time-series NSI across sessions. Hip extension moment had the largest symmetry improvement. Ankle plantarflexion angle was different between Pre-Op and Post-2 yr (p=0.010); and plantarflexion moment was different between Pre- Op and each post-operative session (p<0.001). The time-series Ankle Angle NSI was greater during the early stance phase in the Pre-Op session compared to Post-2 yr.

SIGNIFICANCE

Symmetry across most of the stance phase improved following TAA indicating that TAA successfully improves gait symmetry and future work should determine if these improvements restore symmetry to levels equivalent with health age-match controls.

Postoperative Medial Malleolar Fractures in Total Ankle Replacement Are Associated With Decreased Medial Malleolar Width and Varus Malalignment: A Case-Control Study

BACKGROUND

There are limited data regarding risk factors associated with periprosthetic medial malleolar fractures in total ankle arthroplasty (TAA). This case-control study aimed to identify the risk factors and analyze the effect of prophylactic screw fixation in preventing a medial malleolar fracture after TAA.

METHODS

A case-control study was conducted on 149 patients who underwent primary TAA. Twenty patients with postoperative medial malleolar fractures >4 weeks postoperatively (cases) were identified. An additional 129 patients (controls) were randomly selected from the TAA database. Radiographic evaluation included tibial component coronal alignment and postoperative medial malleolar width. Demographics and radiographic variables were compared between cohorts. Logistic regression was used to investigate the association between medial malleolar fracture and postoperative coronal alignment, medial malleolar width, and prophylactic fixation of the medial malleolus.

RESULTS

Mean (SD) medial malleolar width was significantly smaller in the fracture cohort (8.52 mm [1.6]) than in the control group (11.78 mm [1.74]) (P < .001). Mean (SD) tibial component coronal alignment was 92.17 degrees (2.77) in the fracture cohort and 90.21 degrees (1.66) in the control group (P = .002). Regression analysis identified a significant negative association between postoperative medial malleolar width and the probability of fracture (OR = 0.06, 95% CI 0.01, 0.26, P < .001). Varus malalignment of the tibial component was positively associated with the probability of fracture (OR = 1.90, 95% CI 1.27, 2.86, P = .002). Prophylactic screw fixation resulted in more than 90% reduction in the odds of a fracture (OR = 0.04, 95% CI 0.01, 0.45, P = .01). ROC curve analysis determined a medial malleolar width of 10.3 mm as a potential threshold for predicting fracture.

CONCLUSION

Decreased medial malleolar width and postoperative varus malalignment were associated with an increased risk of postoperative medial malleolar fracture. Therefore, surgeons should consider prophylactic screw fixation in patients with a medial malleolar width <10.3 mm or at risk of postoperative varus deformity.

comparison of postoperative gait parameters after total ankle arthroplasty and ankle fusion: A systematic review

Ankle pathology, such as severe arthritis, often necessitates surgical intervention to restore mobility and alleviate pain. Two commonly performed procedures for end-stage ankle disease are ankle fusion (AF) and total ankle arthroplasty (TAA). This review aims to compare the impact of AF and TAA on postoperative gait parameters. An extensive search in PubMed, Scopus, and Web of Science electronic databases was conducted with the use of the keywords ("ankle arthrodesis" OR "ankle fusion") AND ("ankle replacement" OR "ankle arthroplasty") AND "gait." Clinical studies in terms of postoperative gait parameters were included in this review. At least one of the following gait parameters, included in gait analysis, should be researched: spatiotemporal variables and joint kinematics and kinetics. An initial search revealed 221 studies. After the removal of duplicates and screening of titles,10 studies (7 prospective and 3 retrospective case series) were included for qualitative analysis. In the majority of studies, there is no significant difference in spatiotemporal parameters, such as walking speed, cadence, stance duration, step length, and stride length among AF and TAA patients. Postoperative sagittal ankle ROM, mainly maximum ankle dorsiflexion angle is significantly higher in TAA patients, while results concerning hip and knee ROM are variable. The comparison of AF and TAA in terms of postoperative gait parameters has shown variable results. In the majority of studies, there is no significant difference in spatiotemporal and kinetic parameters among AF and TAA patients. Further high-quality prospective studies are needed to fully elucidate the comparison of postoperative gait parameters.

Gait asymmetry persists following unilateral and bilateral total ankle arthroplasty

Total ankle arthroplasty (TAA) improves gait symmetry in patients with unilateral end-stage ankle arthritis but has not been studied in patients undergoing bilateral TAA (B-TAA), and few studies compare TAA patients to control subjects. The purpose of this study was to compare gait symmetry in U-TAA and B-TAA patients and healthy controls. Using prospective databases, 19 unilateral and 19 bilateral ankle arthritis patients undergoing TAA were matched to 19 control subjects by age, sex, and BMI. The Normalized Symmetry Index (NSI) was determined for joint mechanics and ground reaction forces (GRF) during walking trials at a single visit for controls and preoperatively and 1 to 2 years postoperatively for TAA patients. Data was analyzed using linear mixed-effects models to determine differences among time points and cohorts at a significance of α = 0.05. Following surgery, B-TAA and U-TAA experienced improved peak plantarflexion moment symmetry (p = 0.017) but remained less symmetric than controls. B-TAA patients had more symmetry than U-TAA patients during peak weight acceptance GRF (p = 0.002), while U-TAA patients had greater peak dorsiflexion symmetry than B-TAA patients. TAA patients demonstrated more asymmetry compared to control subjects for all outcome measures. There was no significant impact of TAA on gait symmetry for GRF or peak ankle angles, and neither U-TAA nor B-TAA was consistently associated with higher gait symmetry. These results indicate that TAA improves symmetry during peak plantarflexion moment, and that significant gait asymmetry persists for B-TAA and U-TAA patients compared to healthy participants.

Change of Segmental Motion Following Total Ankle Arthroplasty Using a 3-Dimensional Multi-segment Foot Model

Background

Total ankle arthroplasty (TAA) enhances patients' subjective outcomes with respect to pain and function. The aim of this study was to analyze the biomechanical changes of the affected limb following TAA using gait analysis with a 3-dimensional multi-segment foot model (3D MFM).

Methods

We reviewed medical records, simple radiographs, and gait analyses using a 3D MFM of patients who underwent TAA for severe varus ankle arthritis. Preoperative and postoperative gait data of 24 patients were compared. Postoperative gait analyses were done at least 1 year after surgery.

Results

TAA significantly increased stride length (p = 0.024). The total range of motion of all planes in the hindfoot and forefoot showed no significant changes between preoperative and postoperative states. Hindfoot was significantly plantarflexed and pronated after TAA, while forefoot was significantly supinated in all phases. After appropriate calculations, the genuine coronal motion of the hindfoot showed no changes after TAA in all phases.

Conclusions

TAA did not result in biomechanical improvements of segmental motions in the forefoot and hindfoot, except for changes to the bony structures. Therefore, it is important to point out to patients that TAA will not result in significant improvement of ankle function and range of motion. Clinicians can consider this information during preoperative counseling.

3D kinematics of tibiotalar motion in patients with mobile bearing and fixed bearing total ankle arthroplasty: In vivo videofluoroscopic feasibility study

BACKGROUND

As total ankle arthroplasty (TAA) is an increasingly common surgical intervention for patients with end-stage ankle arthritis, there is a need to better understand the dynamic performance of prosthetic implants during activities of daily living. Our purpose was to quantify and compare relative tibiotalar motion during gait in persons with a fixed-bearing (FB) and mobile-bearing (MB) total ankle arthroplasty. We hypothesized a FB prosthesis would have lower tibiotalar range of motion (ROM).

METHODS

Patients at least 12 months postoperative with either a FB (n=5) or MB (n=3) total ankle arthroplasty were tested. We used high-speed biplanar videoradiography to quantify tibiotalar kinematics during self-selected gait. Angular and linear ROM in three axes were compared between the groups.

RESULTS

ROM for dorsiflexion-plantarflexion, internal-external rotation, and inversion-eversion angles in FB subjects averaged 7.47±4.05°, 7.39±3.63°, and 4.51±2.13°, respectively. ROM in MB subjects averaged 6.74±2.04°, 6.28±4.51°, and 5.68±2.81°, respectively. Linear ROM along anteroposterior, mediolateral, and superior-inferior axes in FB subjects averaged 1.47±2.07 mm, 1.13±1.49 mm, and 0.28±0.30 mm, respectively. Linear ROM in MB subjects averaged 0.68±1.44 mm, 0.60±1.41 mm, and 0.20±0.13 mm, respectively. We found no significant difference between the two groups for any of these ROM parameters (p>0.05).

CONCLUSION

Total ankle arthroplasty using either FB or MB design appears to confer similar ankle motion during the gait cycle in this biplanar fluoroscopic model.

LEVEL OF EVIDENCE

Level IV, case series.

Outcomes After Total Ankle Arthroplasty in Patients Aged ≤50 Years at Midterm Follow-up

BACKGROUND

Ankle arthritis differs from arthritis of the hip and knee in that 80% is posttraumatic and thus often occurs in a younger patient population. The literature supporting total ankle arthroplasty (TAA) in younger patients has increased over recent years and has bolstered the argument that in the short term, TAA in younger patients has successful outcomes that are comparable to older, lower-demand patients.The purpose of our study was to evaluate patient-reported outcomes (PROs) and implant survivorship at midterm after primary TAA in patients ≤ 50 years of age at the time of surgery.

METHODS

A retrospective chart review was conducted of patients ≤ 50 years of age who underwent primary TAA at a single institution from 2000 to 2017. Patient demographics, outcome measures, and complications were recorded. All patients had a minimum clinical follow-up of 5 years. PRO measures were evaluated at preoperative, 1-year postoperative, and final follow-up visits. Paired t tests were performed to compare individual patient changes in PROs from preoperative. Implant survivorship was evaluated based on need for revision of either the tibial or talar component. The need for additional surgery related to the TAA was also evaluated.

RESULTS

A total of 58 patients were included. The average age at the time of the index surgery was 43.3 years (range 22-50 years). All patients had a minimum follow-up of 5 years with a mean follow-up of 8.8 years. A total of 11 patients required additional surgery related to their TAA. Six patients (10.3%) required bone grafting of peri-implant cysts, 3 patients (5.2 %) required gutter debridement, and 1 patient underwent complete revision of metal components. Mean visual analog scale, 36-item Short Form Health Survey, Short Musculoskeletal Function Assessment, and American Orthopaedic Foot & Ankle Society hindfoot scores significantly improved from preoperative to 1-year postoperative and final postoperative follow-up.

CONCLUSION

The patients aged ≤50 years treated with a TAA whom we have been able to observe for a minimum of 5 years showed generally maintained improvement in functional scores and thus far have had a relatively low rate of secondary surgeries.Level of Evidence:Level III, retrospective cohort study.

Effects of Travel Distance on Complications and Outcomes in Total Ankle Arthroplasty

Owing to the last decade's increase in the number of total ankle arthroplasty (TAA) procedures performed annually, there is a concern that the disproportionate distribution of orthopaedic surgeons who regularly perform TAA may impact complications and/or patient satisfaction. This study examines patient-reported outcomes and complications in TAA patients who had to travel for surgery compared to those treated locally. This is a single-center retrospective review of 160 patients undergoing primary TAA between January 2016 and December 2018, with mean age 65 (range: 59-71) years, mean body mass index (BMI) 28.7 kg/m2, 69 (43.1%) females, and mean 1.5 (SD = 0.51) years follow-up. Patients were grouped by distance traveled (<50 miles [n = 89] versus >50 miles traveled [n = 71]). There were no significant differences in rate or type of postoperative complications between the <50 mile group (16.9%) and the >50 mile group (22.5%) (P = .277). Similarly, there were no significant difference in postoperative PROMIS scores between the groups (P = .858). Given uneven distribution of high-volume surgeons performing TAA, this is important for patients who are deciding where to have their TAA surgery and for surgeons on how to counsel patients regarding risks when traveling longer distances for TAA care.Levels of Evidence: Level III: Retrospective Cohort Study.

Total Ankle Arthroplasty in Young Patients

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Evidence Guiding Commercial Payer Coverage Criteria for Total Ankle Arthroplasty

Background

Total ankle arthroplasty (TAA), first developed as an alternative to ankle arthrodesis, has become an increasingly popular management option for end-stage ankle arthritis. Prior studies have shown commercial insurance payers base their coverage criteria on limited and low level of evidence research. This study aims to quantify and describe the evidence insurance companies use to support TAA coverage policies.

Methods

The top 11 national commercial health insurance payers for TAA were identified. A google search was performed to identify payer coverage policies. Policy documents were examined and cited references were classified by type of reference as well as reviewed for level of evidence (LOE). Specific coverage criteria for each individual payer were then extracted. Criteria were compared to assess for similarities among commercial payers. Finally, all references cited by each payer were examined to determine whether they mentioned the specific payer criteria.

Results

Six of the 11 payers had accessible coverage policies. The majority of cited references were primary journal articles (145, 60.9%) and the majority of references cited (179, 75.2%) were level III or level IV evidence. We found significant homogeneity in coverage criteria among payers. In addition, cited sources inconsistently mentioned specific payer coverage criteria.

Conclusion

This study demonstrates that commercial insurance payers rely on the relatively low level of currently available scientific evidence when formulating coverage policies for TAA use and adopt criteria that have not been thoroughly analyzed in the literature. More high level of evidence research is needed to help clinicians and insurance companies further refine indications for TAA so that patients who might benefit from the procedure are adequately covered.

Level of Evidence

Level IV, review.

Influence of Joint Line Level on Clinical Outcomes and Range of Motion in Total Ankle Arthroplasty

BACKGROUND

Ankle arthritis leads to an elevated joint line compared to the nonarthritic ankle, as measured by the "joint line height ratio" (JLHR). Previous work has shown that the JLHR may remain elevated after total ankle arthroplasty (TAA). However, the clinical impact of this has yet to be determined. This study assessed the correlation between postoperative JLHR, post-TAA range of motion (ROM), and 1-year Patient-Reported Outcome Measurement Information System (PROMIS) scores.

METHODS

A retrospective review of 150 patients who underwent primary TAA was performed. Preoperative and postoperative JLHR, as well as postoperative dorsiflexion, plantarflexion, and total ROM, was calculated on weightbearing radiographs at a minimum of 1-year follow-up. Correlation between JLHR, post-TAA ROM, and 1-year PROMIS scores was investigated using Pearson correlation and multiple linear regression models. Interobserver reliability for the JLHR was also calculated.

RESULTS

Interobserver reliability for the JLHR was excellent (r = 0.98). Mean (SD) JLHR changed from 1.66 (0.45) to 1.55 (0.26) after TAA (P < .001), indicating that the joint line was lowered after TAA. An elevated joint line was correlated with decreased post-TAA dorsiflexion (r = -0.26, P < .001), total ROM (r = -0.18, P = .025), and worse 1-year PROMIS physical function (r = -0.22, P = .046), pain intensity (r = 0.22, P = .042), and pain interference (r = 0.29, P = .007). There was no correlation between the JLHR and post-TAA plantarflexion (r = -0.025, P = .76). Regression analysis identified a 0.5-degree reduction in post-TAA dorsiflexion with each 0.1-unit increase in JLHR (Coeff. = -5.13, P = .005).

CONCLUSION

In this patient cohort, we found that an elevated joint line modestly correlated with decreased postoperative dorsiflexion, total ROM, and worse 1-year PROMIS scores. These data suggest that effort likely should be made toward restoring the native joint line at the time of TAA. In addition, future studies investigating the clinical outcomes after TAA may consider including a measure of joint line height, such as the JLHR, because we found it was associated with patient-reported outcomes.

LEVEL OF EVIDENCE

Level III, retrospective review of prospectively collected data.

The Effect of Tibiotalar Joint Line Level Alterations on Tibiotalar Range of Motion Following Total Ankle Arthroplasty

BACKGROUND

The effect of tibiotalar joint line level (TTJL) on patient outcomes following total ankle arthroplasty (TAA) remains unclear. It was previously reported that patients with end-stage ankle arthritis have an elevated TTJL compared with nonarthritic ankles, and the TTJL post-TAA remains elevated compared with nonarthritic ankles. The objectives of this study were to (1) propose a reliable radiographic method to measure the TTJL absolute value and (2) determine the effect of TTJL alterations on tibiotalar range of motion (ROM) following TAA.

METHODS

A retrospective review was performed on patients who underwent TAA between January 2018 and April 2021 with a minimum of 1-year postoperative follow-up and complete perioperative ROM radiographs. Radiographic TTJL and ROM measurements were performed by 2 observers. The proposed TTJL measuring technique computes 4 measurements: high, low, center of the talus (center), and center of the axis (axis). Reliability of measurements and correlation between TTJL measurements and ROM were assessed.

RESULTS

A total of 33 patients were included. Postoperatively, 22 patients had a lowered TTJL compared to 11 patients with an elevated TTJL (2.2 ± 1.3 mm lowered vs 1.9 ± 1.2 mm elevated; P < .0001). Of the 4 TTJL measurements, 3 (low, center, axis) demonstrated a significant positive correlation between lowering the TTJL and improved tibiotalar dorsiflexion and 2 (low, axis) for total ROM (all P < .05). Plantarflexion was not significantly affected by TTJL alterations. Compared to patients with an elevated TTJL, patients with a lowered TTJL had improved tibiotalar dorsiflexion (8.8 vs 2.5 degrees; P = .0015) and total ROM (31.0 vs 22.9 degrees; P = .0191), respectively. The interrater reliability was nearly perfect (intraclass correlation r = 0.96-0.99).

CONCLUSION

In this small series, we found that lowering the TTJL level may more closely reestablish the native TTJL and correlates with improved tibiotalar dorsiflexion and total ROM following TAA.

LEVEL OF EVIDENCE

Level IV, case series.

Bilateral lower extremity gait and function after unilateral total ankle arthroplasty: a case report

BACKGROUND

End-stage ankle osteoarthritis is one of the leading causes of chronic disability in North America. The main purpose of this case report was to describe the functional recovery of a person following total ankle arthroplasty (TAA) surgery using the INFINITY™ system for end stage osteoarthritis of the left ankle.

CASE DESCRIPTION

We report a case of a 55-year-old male who had attempted conservative management for end stage ankle osteoarthritis in his left ankle but ultimately elected to undergo TAA using The INFINITY™ Total Ankle System. He not only had significant left ankle pain limiting his daily function, but also had developed severe right knee pain. We performed gait analysis both before and 6 months after his TAA surgery to examine the sagittal and frontal-plane motions of bilateral ankle, knee, and hip joints during gait.

OUTCOMES

At 6 months post-surgery, the patient demonstrated a 44-point improvement in his Foot and Ankle Outcome questionnaire scores as well as an increase in both left knee and left ankle motion in the sagittal and frontal planes. Kinematic deviations in the left ankle, hip, and knee joints during gait also reduced post-surgery. Despite improvement in his left ankle and overall function, the participant's right knee pain and altered kinematics of the right limb during gait worsened after surgery.

DISCUSSION

Interventions, either before or after ankle surgery, should consider bilateral lower extremities simultaneously in order to optimize patient care and minimize future secondary complications for individuals with unilateral ankle osteoarthritis.

Reconstruction of the Articular Surface in the Subtalar Joint by Osteochondral Autologous Transplantation After Failure of Tibiotalocalcaneal Fusion With a Retrograde Nail: A Case Report

Tibiotalocalcaneal arthrodesis (TTCA) using the intramedullary nail has been conducted for severe deformity of both ankle and subtalar joints. While good clinical outcomes have been reported for TTCA, its nonunion rate is relatively high. We report a case of a 65-year-old male with nonunion of the tibiotalar joint and destruction of the subtalar joint after TTCA using a retrograde intramedullary nail. For this patient, we conducted a salvage procedure for the subtalar joint along with revision surgery for the tibiotalar joint to achieve bone union. The intramedullary nail was removed and the tibiotalar joint was debrided. Two osteochondral plugs were harvested from the lateral aspect of the talus and transplanted to the subtalar joint. The tibiotalar joint was fixed using screws and staples, with bone grafting. Magnetic resonance imaging (MRI) at six months after surgery showed that the articular surface of the subtalar joint was flushed and the osteochondral plugs were united with the surrounding bone. At one year and three months after surgery, the pain in the tibiotalar and subtalar joints had completely disappeared. Plain radiographs revealed that bone union of the tibiotalar joint and joint space of the subtalar joint was maintained. Japanese Society for Surgery of the Foot (JSSF) hindfoot scale improved from 53 points to 84 points at the final follow-up. Reconstruction of the subtalar joint using osteochondral autologous transplantation is a useful technique for failure cases with nonunion of the tibiotalar and subtalar joints after TTCA.

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.

Body Mass Index (BMI) Cutoffs and Racial, Ethnic, Sex, or Age Disparities in Patients Treated With Total Ankle Arthroplasty

Background

The rising prevalence of obesity among American adults has disproportionately affected Black adults and women. Furthermore, body mass index (BMI) has historically been used as a relative contraindication to many total joint arthroplasty (TJA) procedures, including total ankle arthroplasty. The purpose of this study was to investigate potential disparities in patient eligibility for total ankle arthroplasty based on race, ethnicity, sex, and age by applying commonly used BMI cutoffs to the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

Methods

Patients in the ACS-NSQIP database who underwent TAA from 2011 to 2020 were retrospectively reviewed in a cross-sectional analysis. BMI cutoffs of <50, <45, <40, and <35 were then applied. The eligibility rate for TAA was examined for each BMI cutoff, and findings were stratified by race, ethnicity, sex, and age. Independent t tests, chi-squared tests, and Fisher exact tests were performed to compare differences at an α = 0.05.

Results

A total of 1215 of 1865 TAA patients (65.1%) were included after applying the exclusion criteria. Black patients had disproportionately lower rates of eligibility at the most stringent BMI cutoff of <35 (P = .004). Hispanic patients had generally lower rates of eligibility across all BMI cutoffs. In contrast, Asian American and Pacific Islander patients had higher rates of eligibility at the BMI cutoffs of <35 (P = .033) and <40 (P = .039), and White non-Hispanic patients had higher rates of eligibility across all BMI cutoffs. Females had lower eligibility rates across all BMI cutoffs. Ineligible patients were also younger compared to eligible patients across all BMI cutoffs.

Conclusion

Stringent BMI cutoffs may disproportionately disqualify Black, female, and younger patients from receiving total ankle arthroplasty.

Level of Evidence

Level III, retrospective cross-sectional study.

Ankle Joint Salvage for Rigid Flatfoot Deformity

Rigid flatfoot deformity with valgus ankle instability is a complex condition to treat. Thorough clinical and radiographic evaluation is vital to determine treatment strategies. Nonoperative treatment usually relies on bracing or various orthoses. Surgical interventions include ligament reconstruction, osteotomies, arthrodesis, arthroplasty, or a combination of these procedures. Before addressing the ankle deformity, a plantigrade foot is important so a staged approach may be necessary. Misalignment of the ankle replacement can lead to edge loading and early failure. As the implants and our understanding of ankle arthroplasty improve, more patients may benefit from a motion-preserving procedure rather than an arthrodesis.

Reflections on Presurgical and Postsurgical Gait Mechanics After 50 Years of Total Ankle Arthroplasty and Perspectives on the Next Decade of Advancement

Although not the most prevalent form of lower limb pathology, ankle arthritis is one of the most painful and life-limiting forms of arthritis. Developing from overuse and various traumatic injuries, the effect of ankle arthritis on gait mechanics and effective treatment options for ankle arthritis remain an area of extensive inquiry. Although nonsurgical options are common (physical therapy, limited weight-bearing, and steroidal injections), surgical options are popular with patients. Fusion remains a common approach to stabilize the joint and relieve pain. However, starting in the early 1970s, total ankle arthroplasty was proposed as an alternative to fusion.

Short-term Results of Hemiarthroplasty of the Ankle Joint for Talar-Sided Cartilage Loss

Background

Ankle hemiarthroplasty is a 1-piece implant system replacing the talar side of the tibiotalar joint. Hemiarthroplasty offers limited bone resection and may provide easier revision options than joint-ablating procedures.

Methods

Prospective, multicenter, noncomparative, nonrandomized clinical study with short term follow-up on patients undergoing hemiarthroplasty of the ankle. Radiologic and functional outcomes (Foot and Ankle Outcome Score FAOS, Foot and Ankle Ability Measure [FAAM], Short Form-36 Health Survey [SF-36], Short Musculoskeletal Functional Assessment [SMFA], and visual analog scale [VAS] pain scores) were obtained at 3 and 12 months and the last follow-up (mean 31.9 months).

Results

Ten patients met the inclusion criteria. Three were converted to total ankle replacement at 14, 16, and 18 months. Pain VAS scores improved on average from 6.8 to 4.8 (P = .044) of the remaining 7 at a mean of 31.9 months' follow-up. For these 7 in the Survival Group, we found that SF-36 physical health component improved from 25.03 to 42.25 (P = .030), SMFA dysfunction and bother indexes improved from 46.36 to 32.28 (P = .001), and from 55.21 to 30.14 (P = .002) in the Survival Group, and FAAM sports improved from 12.5 to 34.5 (P = .023).

Conclusion

Patients undergoing hemiarthroplasty of the ankle joint for talar-sided lesions had a 30% failure rate by 18 months. Those who did not have an early failure exhibited modest pain reduction, functional improvements, and better quality of life in short-term follow-up. This procedure offers a possible alternative for isolated talar ankle cartilage cases.

Level of Evidence

Level IV, prospective case series.

Tibiopedal Motion Following Tendo-Achilles Lengthening or Gastrocnemius Recession in Total Ankle Replacement: A Comparative Cohort Study

BACKGROUND

End-stage ankle arthritis is a debilitating condition often necessitating total ankle replacement (TAR). Tendo-Achilles lengthening (TAL) and gastrocnemius recession (GR) are commonly performed with TAR to improve ankle dorsiflexion (DF). No studies to date have radiographically analyzed tibiopedal motion to guide surgical management. The purpose of this study is to determine the effect of a TAL or GR during TAR on radiographic tibiopedal range of motion (ROM).

METHODS

A retrospective review of a prospectively maintained database was conducted followed by a propensity score-matched analysis of 110 patients who underwent TAL (n = 26), GR (n = 29), or no lengthening procedure (n = 55) with TAR. Minimum of 1-year ROM radiographic follow-up was required. Exclusion criteria included (1) calcaneal osteotomies, (2) simultaneous or previous hindfoot or midfoot arthrodesis, (3) prior ankle arthrodesis, or (4) revision TAR. Demographic data were extracted from the TAR database. Radiographic assessment included tibiopedal dorsiflexion (DF) and plantarflexion (PF).

RESULTS

DF improved by 2.8 degrees (P = .0286) and by 6.0 degrees (P < .0001) in the TAL and GR cohorts, respectively, with no difference in the control group (+0.7 degrees, P = .3764). PF was decreased by 4.5 degrees (P = .0152) and by 7.2 degrees (P = .0002) in the TAL and GR cohorts, respectively, with no difference in the control group (-0.2 degrees, P = .8546). Minimal differences were observed for total arc of motion for all 3 groups (control 0.5 degrees, GR -1.2 degrees, TAL -1.7 degrees), all of which were nonsignificant (all P > .05). There was no between-group difference in the change in overall arc of motion between the groups (P = .3599). GR resulted in a greater increase in DF (6.0 vs 2.8 degrees; P = .1074), with a reciprocal greater decrease in PF (7.2 vs 4.5 degrees; P = .2416) compared with the TAL cohort.

CONCLUSION

Both TAL and GR increased postoperative DF; however, this was accompanied by a reciprocal loss in PF. Minimal differences were observed for total arc of motion. Patients should be counseled that concomitant procedures performed to increase DF will do so at the expense of PF.

LEVEL OF EVIDENCE

Level III, retrospective review of prospectively collected data.

Gait Analysis in Orthopaedic Surgery: History, Limitations, and Future Directions

Gait analysis has expanding indications in orthopaedic surgery, both for clinical and research applications. Early work has been particularly helpful for understanding pathologic gait deviations in neuromuscular disorders and biomechanical imbalances that contribute to injury. Notable advances in image acquisition, health-related wearable devices, and computational capabilities for big data sets have led to a rapid expansion of gait analysis tools, enabling novel research in all orthopaedic subspecialties. Given the lower cost and increased accessibility, new gait analysis tools will surely affect the next generation of objective patient outcome data. This article reviews the basic principles of gait analysis, modern tools available to the common surgeon, and future directions in this space.

Predicting post-total ankle arthroplasty walking speed based on preoperative gait mechanics

Decreased walking speed is associated with impaired physical performance and function in older adults. Following total ankle arthroplasty (TAA), walking speed continues to be slower than age matched controls. The purpose of this study was to determine if patients 1 year post-TAA can achieve walking speed benchmarks and investigate if gait metrics are predictive of achieved benchmarks. 191 TAA patients were recruited and assessed pre-TAA and 1 year post-TAA. Kinetic and kinematic data were collected during seven self-selected speed barefoot walking trials along a 30-m walkway. Receiver operator curves were generated for each variable to determine threshold values needed to achieve walking speeds of 0.8, 0.9, 1.1, and 1.3 m/s. Each variable's predictive ability was classified according to the area under the curve. Ninety one percent of participants achieved a walking speed > 0.8 m/s, 85.3% achieved ≥0.9 m/s, 64.9% walked at ≥1.1 m/s, and 24.1% achieved a walking speed of 1.3 m/s by 1 year post-TAA. Walking speed pre-TAA was the strongest predictor with ankle moment, power and GRF data showing mixed results. Clinical Significance: 75.9% of participants were unable to walk at 1.3 m/s-a speed indicative of safely crossing a street. Variables predictive of postoperative walking speed benchmarks could be useful in developing interventions for the TAA population. The strongest predictor across all walking speed benchmarks was preoperative walking speed. A walking speed > 0.71 m/s was predictive of achieving 0.8 m/s 1 year post-TAA, while >1.09 m/s predicted 1.3 m/s 1 year post-TAA.

Tranexamic Acid Associated With Less Wound Complications in Ankle and Hindfoot Surgery: Level III, Retrospective Cohort Study

INTRODUCTION

The purpose of this study was to determine whether total ankle arthroplasty (TAA) and ankle/hindfoot fusion patients receiving tranexamic acid (TXA) exhibit fewer wound complications.

METHODS

A retrospective review was conducted of 212 patients (217 feet) undergoing TAA (n = 72), ankle (n = 36), tibiotalocalcaneal (n = 20), pantalar (n = 1), or hindfoot fusion (ie, subtalar = 47, double = 33, and triple = 8) between 2015 and 2020 by a fellowship-trained foot and ankle surgeon at an academic medical center. Demographics, medical history, complications, and union status were compared between TXA (n = 101) and non-TXA (n = 116) cohorts. The mean follow-up was 1.24 years (range, 0.25 to 4.68).

RESULTS

The TXA group had significantly less postoperative infections (5.9% versus 15.5%, P = 0.025). Within a subgroup analysis of ankle/hindfoot fusions, the TXA group exhibited significantly more Charcot neuroarthropathy (20.7% versus 5.7%, P = 0.006) and shorter follow-up duration (0.96 versus 1.30 years, P = 0.030); however, TXA was associated with shorter time to fusion (146 versus 202 days, P = 0.049) and fewer revision surgeries (8.6% versus 21.8%, P = 0.036). Subgroup analysis excluding feet with Charcot also demonstrated less postoperative infections (4.5% versus 14.4%, P = 0.020). Subgroup analysis of TAAs showed fewer cases of superficial infections (2.3% versus 27.6%, P = 0.002) and delayed wound healing (25.6% versus 48.3%, P = 0.047) in the TXA cohort.

DISCUSSION

TXA use in ankle/hindfoot surgery was correlated with a reduction in superficial infections and radiographic time to union. The use of TXA in TAA correlated with fewer superficial infections and cases of delayed wound healing. Thus, in addition to other areas of orthopaedics, TXA seems to be beneficial in hindfoot and ankle surgery.

DATA AVAILABILITY AND TRIAL REGISTRATION NUMBERS

All data were obtained from our institution's medical records. This study is not associated with a clinical trial.

Cadaveric Gait Simulation of the Effect of Subtalar Arthrodesis on Total Ankle Replacement Kinematics

BACKGROUND

Patients undergoing total ankle replacement (TAR) often have symptomatic adjacent joint arthritis and deformity. Subtalar arthrodesis can effectively address a degenerative and/or malaligned hindfoot, but there is concern that it places abnormal stresses on the TAR and adjacent joints of the foot, potentially leading to early TAR failure. This study hypothesized that ankle and talonavicular joint kinematics would be altered after subtalar arthrodesis in the setting of TAR.

METHODS

Thirteen mid-tibia cadaveric specimens with neutral alignment were tested in a robotic gait simulator. To simulate gait, each specimen was secured to a static mounting fixture about a 6-degree of freedom robotic platform, and a force plate moves relative to the stationary specimen based on standardized gait parameters. Specimens were tested sequentially in TAR and TAR with subtalar arthrodesis (TAR-ST_fuse). Kinematics and range of motion of the ankle and talonavicular joint were compared between TAR and TAR-ST_fuse.

RESULTS

There were significant differences in kinematics and range of motion between TAR and TAR-ST_fuse groups. At the ankle joint, TAR-ST_fuse had less internal rotation in early-mid stance (P < .05), with decreased range of motion in the sagittal (-2.7 degrees, P = .008) and axial (-1.8 degrees, P = .002) planes in early stance, and increased range of motion in the coronal plane in middle (+1.2 degrees, P < .001) and late (+2.5 degrees, P = .012) stance. At the talonavicular joint, there were significant differences in axial and coronal kinematics in early and late stance (P < .05). Subtalar arthrodesis resulted in significantly decreased talonavicular range of motion in all planes in early and late stance (P < .003).

CONCLUSION

In ankles implanted with the TAR design used in this study, kinematics of the ankle and talonavicular joint were found to be altered after subtalar arthrodesis. Aberrant motion may reflect altered contact mechanics at the prosthesis and increased stress at the bone-implant interface, and affect the progression of adjacent joint arthritis in the talonavicular joint.

CLINICAL RELEVANCE

These findings may provide a correlate to clinical studies that have cited hindfoot arthrodesis as a risk factor for TAR failure.

Simultaneous Total Ankle Replacement and Contralateral Ankle Arthrodesis for Bilateral Ankle Osteoarthritis: A Retrospective Study Focused on Clinical Outcomes and Cost-effectiveness

Objective

Total ankle replacement (TAR) and ankle arthrodesis (AA) are two common surgical treatment options for end‐stage ankle osteoarthritis. However, few reports compare the outcomes of simultaneous TAR and contralateral AA for bilateral ankle osteoarthritis. The aim of this study was to assess changes in pain, joint range of movement (ROM), functional outcomes, patient satisfaction, and cost‐effectiveness following simultaneous TAR and contralateral AA.

Methods

A retrospective study was conducted on 12 patients with bilateral end‐stage ankle osteoarthritis who underwent simultaneous TAR and contralateral AA in our institution between May 2016 and August 2018, and who had a minimum of two‐year follow‐up data. Clinical and radiological follow‐up data for all patients were collected after 4 months, 1 year and 2 years. The results were assessed clinically on a visual analogue scale (VAS) and included ROM, American Orthopedic Foot and Ankle Society (AOFAS) ankle hindfoot score, and satisfaction questionnaire. The total hospital costs of patients were also recorded. Independent sample t tests were conducted to compare continuous variables between groups. Paired sample t‐tests were conducted to compare changes from the preoperative to postoperative evaluations within each group.

Results

Both surgical groups presented with pain reduction (P < 0.001) at the one‐year postoperative session, which was generally consistent until the two‐year follow‐up. There was a significant increase (P < 0.001) in the mean AOFAS score postoperatively in both ankles. The functional outcomes at the one‐ and two‐year follow‐up were significantly better in patients in the TAR group than in those in the AA group (P < 0.001). Joint ROM differences were observed between the two groups after surgery (decreased ankle ROM in arthrodesis, P < 0.001; increased ankle ROM in arthroplasty, P < 0.001). The mean satisfaction score was 2 (range, 1–4) for the TAR group and 3 (range, 1–5) for the AA group. A significant difference in the satisfaction score was observed between the two groups (P = 0.036). Simultaneous TAR and contralateral AA was 34.1% less expensive than simultaneous bilateral TAR. No intraoperative complications were noted in either group. Wound healing occurred without problems within 2 weeks after surgery. No symptomatic deep venous thrombosis was found during follow‐up.

Conclusion

TAR had better patient‐perceived post‐operative function and preserves more anatomic sagittal plane motion compared to ankles undergoing AA. In addition, simultaneous TAR and contralateral AA are more cost‐effective than simultaneous bilateral TAR, with lower costs for the average patient.

Total Ankle Replacement Provides Symmetrical Postoperative Kinematics: A Biplane Fluoroscopy Imaging Study

BACKGROUND

In vivo measurements of tibiotalar and subtalar joint motion following TAR are unavailable. Using biplane fluoroscopy, we tested the hypothesis that the prosthetic tibiotalar joint and adjacent subtalar joint would demonstrate kinematic and range of motion differences compared to the contralateral untreated limb, and control participants.

METHODS

Six patients of 41 identified candidates that all underwent unilateral Zimmer TAR (5.4 ± 1.9 years prior) and 6 control participants were imaged with biplane fluoroscopy during overground walking and a double heel-rise activity. Computed tomography scans were acquired; images were segmented and processed to serve as input for model-based tracking of the biplane fluoroscopy data. Measurements included tibiotalar and subtalar kinematics for the TAR, untreated contralateral, and control limbs. Statistical parametric mapping quantified differences in kinematics throughout overground walking and the double heel-rise activity.

RESULTS

Patients with this TAR performed walking and heel-rise activities symmetrically with no significant kinematic differences at the tibiotalar and subtalar joints between limbs. Compared to control participants, patients exhibited reduced dorsi/plantarflexion range of motion that corresponded to decreased peak dorsiflexion, but only in the late stance phase of walking. This reduction in tibiotalar dorsi/plantarflexion range of motion in the TAR group became more apparent with double heel-rise activity.

CONCLUSION

Patients with a Zimmer TAR had symmetric kinematics during activities of walking and double heel-rise, but they did exhibit minor compensations in tibiotalar kinematics as compared to controls.

CLINICAL RELEVANCE

The lack of significant kinematic compensation at the subtalar joint may explain why secondary subtalar osteoarthritis is reported as being relatively uncommon in patients with some TAR designs.

Distribution of High-Volume Ankle Replacement Surgeons in United States Metropolitan Areas

BACKGROUND

Ankle osteoarthritis is increasing, thus creating greater demand for high-volume total ankle arthroplasty (TAA) surgeons. The Medicare Provider Utilization and Payment Data Public Use File (MPUPD-PUF) provides volume and reimbursement data for procedures performed by physicians participating in Medicare. This study analyzes surgeon prevalence, surgeon distribution, and factors affecting surgeon prevalence in metropolitan areas.

METHODS

The MPUPD-PUF was reviewed from 2012 to 2015, and data were extracted for physicians performing ≥11 TAA procedures. Physicians in metropolitan areas (population >1 million) were grouped together, and reimbursement, number of high-volume surgeons, and procedures were calculated. Presence of an American Orthopaedic Foot and Ankle Society (AOFAS) fellowship program was analyzed for associations with high-volume TAA surgeons.

RESULTS

Fifty-three surgeons performed ≥11 TAA procedures (1,960 total) covered by Medicare. Of these surgeons, 66% practice in metropolitan areas with a population >1 million. Fifty-one percent of US major metropolitan areas contained no surgeon who submitted >10 traditional Medicare claims for TAA. Areas with an AOFAS fellowship had nominally more TAA claims submitted.

CONCLUSIONS

The distribution of high-volume TAA surgeons among major metropolitan areas in the United States is highly unequal. Analyzing the data with this method aids in targeting TAA surgeons to currently underserved areas.

LEVELS OF EVIDENCE

Level IV: Retrospective-comparative study.

Multi-segment foot kinematics during gait following ankle arthroplasty

Ankle arthritis is a debilitating disease marked by pain and limited function. Total ankle arthroplasty improves pain while preserving motion and offers an alternative to the traditional treatment of ankle fusion. Gait analysis and functional outcomes tools can provide an objective balanced analysis of ankle replacement for the treatment of ankle arthritis. Twenty-nine patients with end-stage ankle arthritis were evaluated before and after ankle arthroplasty. Multi-segment foot and ankle kinematics were assessed annually following surgery (average 3.5 years, range 1-6 years) using the Milwaukee Foot Model and a Vicon video motion analysis system. Functional outcomes (American Orthopedic Foot and Ankle Society [AOFAS] ankle/hindfoot scale, short form 36 [SF-36] questionnaire) and temporal-spatial parameters were also assessed. Kinematic results were compared to findings from a previously collected group of healthy ambulators. AOFAS and SF-36 mean scores improved postoperatively. Walking speed and stride length increased after surgery. There were significant improvements in tibial sagittal range of motion in terminal stance and hindfoot sagittal range of motion in preswing. Decreased external rotation of the tibia and increased external rotation of the hindfoot were noted throughout the gait cycle. Pain and function improved after ankle replacement as supported by better outcomes scores, increased temporal-spatial parameters, and significant improvement in tibial sagittal range of motion during terminal stance and hindfoot sagittal range of motion during preswing. While multi-segment foot kinematics were improved, they were not restored to control values. Statement of clinical significance: Total ankle arthroplasty does not fully normalize mutli-segment gait kinematics despite improved patient-reported outcomes and gait mechanics.

Open Ankle Arthrodesis for Deformity Correction

Open ankle arthrodesis remains a reliable solution for ankle arthritis, especially in the setting of deformity. Careful preoperative evaluation needs to be performed, both clinically and radiographically. The specific deformity present helps determine the approach used and the fixation choices. Deformity is most commonly seen intraarticularly, though deformity can also be present anywhere along the lower extremity, including compensatory deformity in the foot. Multiple different techniques can be used to address both the deformity and achieve a successful ankle arthrodesis. Patient outcomes reported in the literature are generally good, with high union rates and improved functional outcomes.

Deciding Between Ankle and Tibiotalocalcaneal Arthrodesis for Isolated Ankle Arthritis

After isolated ankle (tibiotalar) arthrodesis, the triceps progressively shifts the subtalar joint into varus thus blocking compensatory motion from the midtarsal joints. In a tibiotalocalcaneal arthrodesis, the subtalar may be fixed with the correct valgus. Comparison between ankle and tibiotalocalcaneal arthrodesis does not clearly favor one over another for pain relief, satisfaction, and gait analysis. Compensatory sagittal plane motion through the midtarsal joints when the subtalar is fixed in valgus may be responsible for these results. Tibiotalocalcaneal arthrodesis has become our procedure of choice over isolated tibiotalar for end-stage ankle arthritis regardless of the radiographic state of the subtalar.

Patient-Reported Outcomes of Primary Total Ankle Arthroplasty in Patients Aged <50 Years

Background:

Compared to more prevalent arthritic conditions, ankle arthritis is complicated by an earlier age of onset. Recently published data demonstrates excellent survivorship and complication rates in short-/midterm follow-up of younger patients who received a primary total ankle arthroplasty (TAA). Additionally, older TAA patients display comparable reported outcomes relative to hip/knee arthroplasty. However, there remains a paucity of literature surrounding the reported outcomes of younger patients undergoing TAA. Thus, our aim was to assess the reported outcomes of individuals aged <50 years receiving a primary TAA.

Methods:

A retrospective cohort analysis of adult patients <50 years who received a primary total ankle replacement was conducted. Patient demographics, diagnosis, treatment, and outcome characteristics were recorded from a chart review of 41 patients with at least 1 year of postoperative clinical follow-up. Postoperative reported outcomes were obtained via telephone interviews. Primary outcomes that were measured included emotional and physical health, activity limitation, ambulation, and global health. Measures used included the 36-Item Short Form Health Survey (SF-36), Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health, and Sickness Impact Profile Ambulation. The functional outcomes in our study sample were compared with age- and gender-matched norms from a general US population, and 95% CIs were calculated for each functional outcome mean. Student t test was used for continuous variables, and χ² analysis was used for categorical variables.

Results:

Thirty-one of 41 eligible patients were reached for interview. The average age at surgery was 39.7 years. Clinical and radiographic follow-up was a mean of 51.6 months and 31.2 months following TAA, respectively. General health as measured with the SF-36 was not significantly different from age-/gender-matched norms. Eighty-seven percent of patients would choose to have a TAA again. Although 58% reported being limited in vigorous activities, 61% were able to ambulate frequently for long periods of time. On average, the patients did not report ongoing pain, and only 16% reported fatigue that hindered activities. Eighty-one percent reported returning to full employment and performing their duties without difficulty, and 84% reported they resumed all normal social activities. Primary implant survivorship was 93%.

Conclusion:

Despite a younger age and potentially increased demands, patients aged <50 years undergoing primary TAA are generally satisfied with their index procedure at a mean follow-up of nearly 5 years. Our findings of positive outcomes on their health and well-being may improve surgeon insight for TAA as an alternative treatment for younger individuals with end-stage ankle arthritis.

Level of Evidence: Level IV, case series.

Ankle Osteoarthritis

Osteoarthritis (OA) is characterized by a chronic, progressive and irreversible degradation of the joint surface associated with joint inflammation. The main etiology of ankle OA is post-traumatic and its prevalence is higher among young and obese people. Despite advances in the treatment of fractures around the ankle, the overall risk of developing post-traumatic ankle OA after 20 years is almost 40%, especially in Weber type B and C bimalleolar fractures and in fractures involving the posterior tibial border. In talus fractures, this prevalence approaches 100%, depending on the severity of the lesion and the time of follow-up. In this context, the current understanding of the molecular signaling pathways involved in senescence and chondrocyte apoptosis is fundamental. The treatment of ankle OA is staged and guided by the classification systems and local and patient conditions. The main problems are the limited ability to regenerate articular cartilage, low blood supply, and a shortage of progenitor stem cells. The present update summarizes recent scientific evidence of post-traumatic ankle OA with a major focus on changes of the synovia, cartilage and synovial fluid; as well as the epidemiology, pathophysiology, clinical implications, treatment options and potential targets for therapeutic agents.

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.

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.

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 With Valgus Deformity

BACKGROUND

A substantial coronal plane deformity is common in the context of end-stage ankle osteoarthritis. Recent literature shows a trend toward extending the indication of total ankle arthroplasty in increasingly severe coronal deformities, showing promising results when correct alignment is achieved. Nevertheless, the results of lateral transfibular total ankle replacement (LTTAR) in valgus has not been extensively studied. We aimed to evaluate if the outcomes of LTTAR in ankles with valgus deformity were similar to those with no major deformity at short-term follow-up.

METHODS

This retrospective cohort study included 228 LTTARs. Patients were classified into 2 groups according to the preoperative coronal plane tibiotalar angle (TTS): neutral (less than 10 degrees of coronal deformity, 209 patients) and valgus (above 10 degrees of valgus, 19 patients). Clinical evaluation was performed using the American Orthopaedic Foot & Ankle Society (AOFAS) score, visual analog scale (VAS), 12-Item Short Form Health Survey 12 (SF-12) regarding its Physical and Mental Component Summary items. The radiographic evaluation considered anteroposterior and lateral ankle radiographs. Complications were also registered and classified as major or minor. The minimum follow-up was 2 years.

RESULTS

The average AOFAS, VAS, and SF-12 scores improved significantly postoperatively (P < .001), without differences between groups. At final radiographic follow-up, the valgus alignment group did not show significant differences with the neutral alignment group regarding TTS, lateral distal tibial angle, or anterior distal tibial angle (P > .05).

CONCLUSION

LTTAR in cases with valgus deformity achieved and maintained correction at short-term follow-up, as obtained in neutral alignment ankles. Clinical outcomes improved significantly regardless of preoperative valgus deformity.

LEVEL OF EVIDENCE

Prognostic Level III, retrospective cohort study.

Clinical Outcomes of Total Ankle Arthroplasty Versus Ankle Arthrodesis for the Treatment of End-Stage Ankle Arthritis in the Last Decade: a Systematic Review and Meta-analysis

Ankle arthrodesis (AA) and total ankle arthroplasty (TAA) are the 2 primary surgical treatments for patients with end-stage ankle arthritis. The comparative outcomes between AA and TAA using modern techniques remain unclear. A systematic search to identify all relevant articles comparing AA with TAA was conducted through 3 online databases. The clinical outcomes were extracted for meta-analysis, including AOFAS (American Orthopaedic Foot & Ankle Society) score, VAS (visual analog scale), AOS (Ankle Osteoarthritis Scale), gait analysis, ROM (range of motion), satisfaction, complication, and reoperation. Our meta-analysis shows no heterogeneity in any subgroup analyses. There were no significant differences in AOFAS total, pain, and alignment scores between the AA and TAA groups. The TAA group had significant improvement in AOFAS function score compared with the AA group. There was no significant difference in VAS and AOS total scores between the 2 groups. No significant differences in gait analysis were observed between the 2 groups. The TAA group had significant improvement in both ROM and change in ROM compared with the AA group. There was no significant difference in satisfaction rate between the 2 groups. The TAA group had significantly higher complication and reoperation rates compared with the AA group. Our meta-analysis provides updated evidence on clinical outcomes comparing AA with TAA using third-generation implants. The TAA group had better improvement in AOFAS function and ROM than the AA group. No significant differences in pain relief, gait analysis, or patient satisfaction were observed between the 2 groups.

End-stage ankle osteoarthritis: arthroplasty offers better quality of life than arthrodesis with similar complication and re-operation rates-an updated meta-analysis of comparative studies

PURPOSE

Ankle arthrodesis (AA) has traditionally been the surgical standard for patients with an end-stage ankle osteoarthritis, with total ankle arthroplasty (TAA) recently becoming an alternative. The aim of this study was to update evidence in terms of functional outcomes, complications, and quality of life between AA and TAA by analyzing comparative studies.

METHODS

PubMed, MEDLINE, Scopus, and Cochrane Central databases were used to search keywords. A total of 21 studies entered our qualitative and quantitative analysis. Demographics, functional outcomes, and complications were extracted. Random and fixed-effect models were used for the meta-analysis of standardized mean differences (SMDs) and odds ratios (ORs).

RESULTS

A total of 18,448 patients were identified, with a mean age of 57.3 ± 11.3 years. TAA showed significantly greater post-operative range of motion (SMD - 0.883, 95% CI - 1.175 to - 0.590; I² < 0.001) and Ankle Osteoarthritis Scale scores (SMD - 1.648, 95% CI - 3.177 to - 0.118; I² = 97.67), but no differences in other patient-reported outcome scores were found. Patients undergoing TAA showed higher post-operative SF-36 (SMD - 0.960, 95% CI - 1.584 to - 0.336; I² = 68.77). The total complication rate was similar between the two procedures (OR 0.936, 95% CI 0.826 to 1.060; I² = 87.44), including the incidence of re-operations (OR 1.720, 95% CI 0.892 to 3.316; I² = 77.65).

CONCLUSION

While TAA and AA showed no differences in most post-operative functional outcomes, our review demonstrates that patients undergoing TAA show better health-related quality of life than AA. We found no evidence to suggest that TAA carries a higher risk of complications and re-operations compared to AA.

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.

Takedown of Painful Ankle Arthrodesis to Total Ankle Arthroplasty: A Case Series of 77 Patients

Treatment of painful or malaligned ankle arthrodesis can present as a challenging issue. Several published studies have demonstrated that takedown of a painful ankle arthrodesis to total ankle arthroplasty can assist in restoring some sagittal plane motion and improving functional scores. The goal of this study was to contribute to the limited body of literature with the largest cohort and longest follow-up to date. A retrospective analysis was performed on patient and surgical characteristics of those who underwent a conversion of a painful ankle arthrodesis to a total ankle arthroplasty by 1 of 3 experienced total ankle arthroplasty surgeons from February 2003 to December 2016 with ≥2 years of follow up. Seventy-seven subjects were included for evaluation, with an implant retention rate of 88% (68 of 77) and mean follow-up of 8.3 years (range 2.6 to 15.8). Of the 11 (14%) failures (defined as retrieval or exchange of metallic components), 8 (10%) were revised to a total ankle replacement, 2 (2%) underwent revision arthrodesis, and 1 (1%) elected for below-the-knee amputation. The mean time since the primary arthrodesis was 8.6 years (range 1 to 44), and the longer time interval between primary arthrodesis to takedown total ankle arthroplasty did not correlate with poorer outcome scores or increased risk of failure. The mean American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot, Buechel-Pappas, and visual analog pain scale scores improved from preoperative values, with less satisfaction noted in those who needed revision surgery. The conversion of a painful ankle arthrodesis to a total ankle implant is a viable option to obtain range of motion and improved patient satisfaction scores similar to primary total ankle replacement.

Effect of Achilles Tendon Lengthening and Gastrocnemius Recession on Radiographic Tibiotalar Motion Following Total Ankle Replacement

BACKGROUND

Surgeons frequently add an Achilles tendon lengthening or gastrocnemius recession to increase dorsiflexion following total ankle replacement. Previous studies have looked at the effects of these procedures on total tibiopedal motion. However, tibiopedal motion includes motion of the midfoot and hindfoot as well as the ankle replacement. The current study examined the effects of Achilles tendon lengthening and gastrocnemius recession on radiographic tibiotalar motion at the level of the prosthesis only.

METHODS

Fifty-four patients with an average of 25 months follow-up after total ankle replacement were divided into 3 groups: (1) patients who underwent Achilles tendon lengthening, (2) patients who had a gastrocnemius recession, (3) patients with no lengthening procedure. Tibiotalar range of motion was measured on lateral dorsiflexion-plantarflexion radiographs using reference lines on the surface of the implants.

RESULTS

Both Achilles tendon lengthening and gastrocnemius recession significantly increased tibiotalar dorsiflexion when compared to the group without lengthening. However, the total tibiotalar range of motion among the 3 groups was the same. Interestingly, the Achilles tendon lengthening group lost 11.7 degrees of plantarflexion compared to the group without lengthening, which was significant.

CONCLUSION

Both Achilles tendon lengthening and gastrocnemius recession increased radiographic tibiotalar dorsiflexion following arthroplasty. Achilles tendon lengthening had the unexpected effect of significantly decreasing plantarflexion. Gastrocnemius recession may be a better choice when faced with a tight ankle replacement because it increases dorsiflexion without a compensatory loss of plantarflexion.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Functional Outcomes of Total Ankle Arthroplasty at a Mean Follow-up of 7.6 Years: A Prospective, 3-Dimensional Gait Analysis

BACKGROUND

In vivo gait analysis provides objective measurement of patient function and can quantify that function before and after ankle reconstruction. Previous gait studies have shown functional improvement for up to 4 years following total ankle arthroplasty (TAA), but to date, there are no published studies assessing function at ≥5 years following TAA. We hypothesized that patients who underwent TAA would show significant improvements in walking function at a minimum follow-up of 5 years, compared with their preoperative function, as measured by changes in temporospatial, kinematic, and kinetic gait parameters.

METHODS

Three-dimensional gait analysis with a 12-camera digital motion-capture system and double force plates was utilized to record temporospatial, kinematic, and kinetic measures in 33 patients who underwent TAA with either the Scandinavian Total Ankle Replacement (Stryker; n = 28) or Salto Talaris Ankle (Integra LifeSciences; n = 5). Gait analysis was performed preoperatively and at a minimum follow-up of 5 years (mean, 7.6 years; range, 5 to 13 years).

RESULTS

Significant improvements were observed in multiple gait parameters, with temporospatial increases in cadence (+9.5 steps/min; p < 0.0001), step length (+4.4 cm; p = 0.0013), and walking speed (+0.2 m/s; p < 0.0001), and kinematic increases in total sagittal range of motion (+2.0°; p = 0.0263), plantar flexion at initial contact (+2.7°; p = 0.0044), and maximum plantar flexion (+2.0°; p = 0.0488). Kinetic analysis revealed no loss of peak ankle power, despite patients aging.

CONCLUSIONS

To our knowledge, this is the first study to report 7-year functional outcomes of TAA, quantified by objective, in vivo measurements of patient gait. Patients were shown to have sustained improvement in multiple objective parameters of gait compared with preoperative function.

LEVEL OF EVIDENCE

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

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.

A Survey for End-Stage Ankle Arthritis Treatment: Ankle Arthrodesis Versus Ankle Arthroplasty

With promising technological advances, ankle arthroplasty has become an alternative to arthrodesis, traditionally the gold standard, for treating end-stage ankle arthritis. We collected knowledge and perceptions on both procedures to determine the need for a patient decision aid for these patients by administering a cross-sectional survey to 103 orthopaedic surgeons. Respondents were predominantly male and 41 to 50 years old. Half of those who stated that they do not perform arthroplasty said this was because they do not have adequate training. Additionally, certain variables were associated with the surgeon's choice of intervention: patient gender, age, body mass index, postoperative activity level, employment type, perceived risk of infection, neurovascular injury or wound complication, risk of developing or pre-existing adjacent arthritis, deformity, malalignment, bone loss or abnormal bone quality, number of prior ankle operations, cause of arthritis, and desire for motion preservation. The majority agreed that they always incorporate patient preferences into their decisions and that a decision aid would be beneficial. This survey revealed that several patient characteristics are influential in the surgeon's preference for either arthroplasty or arthrodesis for end-stage ankle arthritis. Because the majority of surgeons incorporate patient preferences in their decisions and report that a decision aid would be beneficial for informed decision-making in this clinical scenario, this survey identified an unmet need supporting the development of such a tool for these patients.

Loss of Mechanical Ankle Function Is Not Compensated by the Distal Foot Joints in Patients with Ankle Osteoarthritis

BACKGROUND

Patients with isolated ankle osteoarthritis (OA) often demonstrate disturbed ankle biomechanics during walking. Clinicians often believe that this triggers the distal foot joints to compensate these altered ankle biomechanics and that these foot joints are consequently subjected to degenerative joint diseases due to overuse.

QUESTIONS/PURPOSES

Do patients with isolated ankle OA differ from those without ankle OA in terms of (1) ankle and foot joint kinematics and (2) ankle and foot joint kinetics as measured using three-dimensional (3-D) gait analysis? (3) Do these patients demonstrate compensatory strategies in their Chopart, Lisfranc, or first metatarsophalangeal joints in terms of increased joint kinematic and kinetic outputs?

METHODS

Between 2015 and 2018, we treated 110 patients with unilateral ankle OA, and invited all of them to participate in the gait analysis laboratory. Of those, 47% (52) of patients did so, and of these, 16 patients met the inclusion criteria for this study, which were (1) diagnosis of unilateral ankle OA; (2) absence of radiographical signs of OA in the contralateral foot or lower limbs; (3) ability to walk at least 100 m without rest; and (4) being older than 18 years of age. A control group (n = 25) was recruited through intranet advertisements at the University Hospitals of Leuven. Participants were included if their age matched the age-range of the patient group and if they had no history of OA in any of the lower limb joints. Patients were slightly older (55.9 ± 11.2 years), with a slightly higher BMI (28 ± 6 kg/m2) than the control group participants (47.2 ± 4.4 years; p = 0.01 and 25 ± 3 kg/m2; p = 0.05). All participants underwent a 3-D gait analysis, during which a multisegment foot model was used to quantify the kinematic parameters (joint angles and ROM) and the kinetic parameters (rotational forces or moments), as well as power generation and absorption in the ankle, Chopart, Lisfranc, and first metatarsophalangeal joints during the stance phase of walking. Peak values were the maximum and minimum values of waveforms and the latter were time-normalized to 100% of the stance phase.

RESULTS

Regarding joint kinematics, patients demonstrated a sagittal plane ankle, Chopart, Lisfranc, and first metatarsophalangeal joint ROM of 11.4 ± 3.1°, 9.7 ± 2.7°, 8.6 ± 2.3° and 34.6 ± 8.1°, respectively, compared with 18.0 ± 2.7° (p < 0.001), 13.9 ± 3.2° (p < 0.001), 7.1 ± 2.0° (p = 0.046) and 38.1 ± 6.5° (p = 0.15), respectively, in the control group during the stance phase of walking. With regard to joint kinetics in the patient group, we found a mean decrease of 1.3 W/kg (95% CI confidence interval 1.0 to 1.6) (control group mean: 2.4 ± 0.4 W/kg, patient group mean: 1.1 ± 0.5 W/kg) and 0.8 W/kg (95% CI 0.4 to 1.0) (control group mean: 1.5 ± 0.3 W/kg, patient group mean: 0.7 ± 0.5 W/kg) of ankle (p < 0.001) and Chopart (p < 0.001) joint peak power generation. No changes in kinetic parameters (joint moment or power) were observed in any of the distal foot joints.

CONCLUSION

The findings of this study showed a decrease in ankle kinematics and kinetics of patients with isolated ankle OA during walking, whereas no change in kinematic or kinetic functions were observed in the distal foot joints, demonstrating that these do not compensate for the mechanical dysfunction of the ankle.

CLINICAL RELEVANCE

The current findings suggest that future experimental laboratory studies should look at whether tibiotalar joint fusion or total ankle replacement influence the biomechanical functioning of these distal joints.

The Biomechanical Behavior of Distal Foot Joints in Patients with Isolated, End-Stage Tibiotalar Osteoarthritis Is Not Altered Following Tibiotalar Fusion

Ankle arthrodesis is considered to be an optimal treatment strategy to relieve pain during walking in patients with isolated, end-stage tibiotalar osteoarthritis. The aim of this study was to investigate the post-operative effect of an arthrodesis on the ankle and foot joint biomechanics. We included both patients (n = 10) and healthy reference data (n = 17). A multi-segment foot model was used to measure the kinematics and kinetics of the ankle, Chopart, Lisfranc, and first metatarsophalangeal joints during a three-dimensional (3D) gait analysis. These data, together with patient reported outcome measures, were collected at baseline (pre-operative) and one year post-operatively. Patients experienced a decrease in pain and an increase in general well-being after surgery. Compared to the baseline measurements, patients only demonstrated a significant average post-operative increase of 0.22 W/kg of power absorption in the ankle joint. No other significant differences were observed between baseline and post-operative measurements. Current findings suggest that the biomechanical behavior of distal foot joints is not altered one year after fusion. The pain relief achieved by the arthrodesis improved the loading patterns during walking. Clinical significance of this study dictates that patients do not have to fear a loss in biomechanical functionality after an ankle arthrodesis.