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

Discrepancies Between Intraoperative and Postoperative Ankle Motion Measured for Anterior-Approach Total Ankle Arthroplasty

BACKGROUND

Although intraoperative ankle motion serves as a foundational reference for anticipated motion after surgery and guides the addition of procedures to enhance ankle motion in total ankle arthroplasty (TAA), the relationship between intraoperative and postoperative ankle motion remains unclear. This study aimed to investigate the discrepancy between intraoperative and postoperative ankle range of motion (ROM) following TAAs using the anterior-approach, fixed-bearing systems.

METHODS

This study retrospectively reviewed 67 patients (67 ankles) who underwent primary TAA at a single institution. Three different types of anterior-approach, fixed-bearing TAA systems were included. Intraoperative fluoroscopy was used to document the maximal dorsiflexion and plantar flexion at the end of the case. Standardized weightbearing maximum dorsiflexion and plantar flexion sagittal radiographs were obtained pre- and postoperatively, following a previously described method. The motion between 3 different time points (preoperative, intraoperative, and postoperative [mean 11.4 months]) was compared using pairwise t tests, and their differences were quantified.

RESULTS

The mean total tibiotalar ROM was 38.1 degrees (SD 7.8) intraoperatively, and the postoperative total tibiotalar ROM was 24.2 degrees (SD 9.7) (P < .001), indicating that a mean of 65.3% (SD 26.7) of the intraoperative motion was maintained postoperatively. Intraoperative dorsiflexion (mean 11.6 [SD 4.5] degrees) showed no evidence of difference from postoperative dorsiflexion (mean 11.4 [SD 5.8] degrees, P > .99), indicating that a median of 95.6% (interquartile range: 66.2-112) of the intraoperative maximum dorsiflexion was maintained postoperatively. However, there was a significant difference between intraoperative plantarflexion (mean 26.4 [SD 6.3]) and postoperative plantarflexion (12.8 [SD 6.9] degrees, P < .001), indicating a mean 50.6% (SD 29.6) of intraoperative motion maintained in the postoperative assessment. There was an improvement of 2.5 degrees in the total tibiotalar ROM following TAA with statistical significance (P < .043).

CONCLUSION

This study revealed a significant difference between intraoperative ankle ROM and ankle ROM approximately 1 year after anterior-approach, fixed-bearing TAA, mainly due to plantarflexion motion restriction. Minimal difference in dorsiflexion suggests the importance of achieving the desired postoperative dorsiflexion motion during the surgery using the best possible adjunct procedures.

LEVEL OF EVIDENCE

Level IV, case series.

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.

Obesity and Ankle Prosthesis Revision: A Systematic Review and Meta-analysis

BACKGROUND

The increasing number of total ankle arthroplasties (TAAs) has led to growing evidence on the risk factors for complications after surgery. However, the role of obesity in this patient group has been the subject of much debate. Therefore, this systematic review aimed to investigate the evidence for untoward effects of obesity following TAA.

METHODS

We conducted a comprehensive search on April 28, 2023, in MEDLINE (via PubMed), Embase, and CENTRAL. Eligible observational studies reported on the short- and long-term outcomes of primary TAA, comparing patients with and without obesity (defined as body mass index > 30). Using a random effects model, we calculated pooled odds ratios (ORs) with 95% confidence intervals (CIs) from 2 by 2 tables (event and nonevent in the obese and nonobese primary TAA groups).

RESULTS

Nine studies with 10 388 patients were eligible for inclusion in the meta-analysis. We found significantly higher odds of revision in the obese group compared to the nonobese group (OR = 1.68, CI: 1.44-1.95). However, the odds of overall perioperative complications (OR = 1.55, CI: 0.50-4.80) and wound complications (OR = 1.34, CI: 0.29-6.20) were nonsignificantly higher in the obese group.

CONCLUSION

Based on our results, obesity may have affected long-term outcomes following TAA and may have negatively affected the prosthesis's survival.

Changes in Relative Work of the Lower Extremity and Distal Foot Joints After Total Ankle Replacement: An Exploratory Study

Ankle osteoarthritis does not only led to lower ankle power generation, but also results in compensatory gait mechanics at the hip and Chopart joints. Much of previous work explored the relative work distribution after total ankle replacement (TAR) either across the lower extremity joints where the foot was modelled as a single rigid unit or across the intrinsic foot joints without considering the more proximal lower limb joints. Therefore, this study aims, for the first time, to combine 3D kinetic lower limb and foot models together to assess changes in the relative joint work distribution across the foot and lower limb joints during level walking before and after patients undergo TAR. We included both patients and healthy control subjects. All patients underwent a three-dimensional gait analysis before and after surgery. Kinetic lower limb and multi-segment foot models were used to quantify all inter-segmental joint works and their relative contributions to the total lower limb work. Patients demonstrated a significant increase in the relative ankle positive joint work contribution and a significant decrease in the relative Chopart positive joint work contribution after TAR. Furthermore, there exists a large effect toward decreases in the relative contribution of the hip negative joint work after TAR. In conclusion, this study seems to corroborate the theoretical rationale that TAR reduces the compensatory strategy in the Chopart and hip joints in patients suffering from end-stage ankle osteoarthritis.

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.

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

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

Survivorship of 4,748 Contemporary Total Ankle Replacements from the French Discharge Records Database

BACKGROUND

Studies of survivorship of primary total ankle replacements (TARs) beyond 5 years have shown varying results among early and modern designs. National cohorts give valuable insights about TAR outcomes, revision risk factors, and specific designs. The purpose of this study was to investigate implant survivorship and risk factors for revision of contemporary TARs using our national database.

METHODS

This observational study included patients identified in the national PMSI (Programme médicalisé des systèmes d'information) database as having undergone TAR from 2010 to 2019. Demographics, discharge data, concomitant procedures, and type of implant were extracted. Kaplan-Meier estimations were performed to determine time to revision using metal component revision for implant failure and revision for deep infection as end points. Weighted Cox models were used for risk factor analysis, including risks of early revision (within the first 2 years). The adjusted hazard ratios (HRadj) were reported with 95% confidence intervals.

RESULTS

A cohort of 4,748 patients was extracted. The mean age at surgery was 63 years; 43% of the patients were female. The mean follow-up was 5 years (range, 1 to 10 years). Revisions were noted in 817 cases (17%), including 734 with metal component revision and 83 with revision due to deep infection. The 1-year, 2-year, 5-year, and 10-year survivorship free of metal component revision was 95%, 90%, 84%, and 78%, respectively. Younger age, implants derived from second-generation designs, and an institutional volume of ≤10 TARs per year were found to be independent predictors of revision for any cause. In addition to the above factors (except for implant generation), male sex and concomitant osteotomies and/or fusion were found to be significant predictors for any early revision.

CONCLUSIONS

The 10-year survivorship free of metal component revision after TAR was 78%, which was consistent with other national registries. Revisions were associated with young age, associated arthritis or deformities requiring concomitant fusion or osteotomy, and implants derived from second-generation designs. Institutions where >10 procedures were performed per year were associated with better TAR survivorship.

LEVEL OF EVIDENCE

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

Clinical efficacy of the Ankle Spacer for the treatment of multiple secondary osteochondral lesions of the talus

BACKGROUND

The Ankle Spacer was developed as a joint-sparing alternative to invasive end-stage surgeries. Currently, there are no clinical studies on the Ankle Spacer.

AIM

To describe the operative technique and the clinical efficacy of the Ankle Spacer for the treatment of multiple, cystic osteochondral lesions of the talus in patients with failed prior operative treatment.

METHODS

This is a prospective study during which patients were assessed preoperatively, at 2- and 6 wk, and at 3, 6, 12 and 24 mo postoperatively. Patients with multiple, cystic or large (≥ 15 mm) osteochondral lesions of the talus after failed prior surgery were included. The primary outcome measure was the numeric rating scale (NRS) for pain during walking at 2 years postoperatively. Secondary outcome measures included the NRS in rest and during stair climbing, the American Orthopaedic Foot and Ankle Society Hindfoot Score, the Foot and Ankle Outcome Score, the Short- Form 36 physical and mental component scale, and the Range of Motion (ROM). Radiographic evaluations were conducted to evaluate prosthetic loosening and subsidence. Revision rates and complications were also assessed.

RESULTS

Two patients underwent an Ankle Spacer implantation on the talus. The NRS during walking improved from 6 and 7 preoperatively to 2 and 2 points postoperatively at 2 years, in patient 1 and 2, respectively. The other patient-reported outcome measures also improved substantially. There were no re-operations nor complications. Radiological imaging showed no loosening of the implant and no change of implant position.

CONCLUSION

The Ankle Spacer showed clinically relevant pain reduction during walking, improvement in clinical outcomes as assessed with PROMs, and no complications or re-operations. This treatment option may evolve as a joint-sparing alternative to invasive end-stage surgeries.

Preoperative Gait Analysis of Peroneal Tendon Tears

BACKGROUND

Little is known regarding the impact of peroneal tendon tears on function. This study quantifies gait changes associated with operatively-confirmed peroneal tendon tears.

METHODS

Sixty-five patients with unilateral peroneal tendon tears were prospectively evaluated using preoperative 3D multisegment gait analysis of both limbs. Data were analyzed according to pattern/severity of tears, as confirmed surgically: peroneus brevis tears, reparable (PBR); peroneus brevis tears, irreparable (PBI); peroneus longus tears, irreparable (PLI); and concomitant irreparable tears of both tendons (PBI+PLI). The following parameters were analyzed: ankle sagittal motion, coronal motion, axial rotation, foot progression angle, sagittal power, sagittal moment.

RESULTS

Twelve patients (18.5%) had the PBR pattern, 37 (56.9%) PBI, 10 (15.4%) PLI, and 6 (9.2%) PBI+PLI. Compared with the contralateral, nonpathologic extremities, limbs with peroneal tears had diminished ankle sagittal motion (mean 23.14 vs 24.30 degrees, P = .012), ankle/hindfoot axial rotation (6.26 vs 7.23 degrees, P = .001), sagittal moment (1.16 vs 1.29 Nm/kg, P < .001), and sagittal power (1.24 vs 1.47 W/kg, P < .001). The most severe tear patterns had the greatest derangements in multiple parameters of gait (PBI+PLI > PBI or PLI > PBR). For example, all groups except PBR had loss of ankle sagittal moment and/or power in the affected limb, and the greatest losses in moment and power were in the PBI+PLI group (1.22 vs 0.91 Nm/kg, P = .003 for moment; 0.73 vs 1.31 W/kg, P < .001 for power). The PBI+PLI group had a >10-degree varus shift in coronal motion on the affected side (P = .002).

CONCLUSION

This is the first study to demonstrate diminished biomechanical function in patients with peroneal tendon tears. In vivo 3-dimensional gait analysis found significant changes in hindfoot motion, ankle motion, and ankle power. Impairments were related to the pattern and severity of the tears, and demonstrated a strong association of peroneal tendon tears with diminished ankle plantarflexion strength.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.