In advanced stages of ankle osteoarthritis (OA), ankle arthrodesis (AA) or total ankle arthroplasty (TAR) may be necessary. Our purpose is to compare AA and total ankle replacement for the surgical ...management of end stage ankle OA.
We conducted a literature search of PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar databases using the terms 'ankle' in combination with 'OA', 'arthrodesis', 'arthroplasty', 'joint fusion', 'joint replacement'. Studies where treatment was exclusively total ankle replacement or AA were excluded. Treatment characteristics and outcome parameters (overall postoperative outcome and complication rate) were reviewed.
When counseling patients who are considering their options with regard to ankle arthritis treatment, surgeons should determine on an individual basis which procedure is more suitable.
TAR has become an accepted treatment for end-stage OA, but revision rates for TAR are significant higher than for AA (odds ratio 2.28 95% confidence interval CI, 1.63-3.19; P < 0.0001).
The results of TAA are gradually improving, but the procedure cannot yet be recommended for the routine management of ankle OA.
Although there is some evidence to support TAR to conserve ankle motion and offer improved function and decreased pain with high satisfaction rates, revision rates for TAR are significantly higher than revision rates for AA. Proper patient selection should be better addressed in future studies for successful treatment of end-stage ankle OA.
Systematic review, level III.
In human locomotion, we continuously modulate joint mechanical impedance of the lower limb (hip, knee, and ankle) either voluntarily or reflexively to accommodate environmental changes and maintain ...stable interaction. Ankle mechanical impedance plays a pivotal role at the interface between the neuro-mechanical system and the physical world. This paper reports, for the first time, a characterization of human ankle mechanical impedance in two degrees-of-freedom simultaneously as it varies with time during walking. Ensemble-based linear time-varying system identification methods implemented with a wearable ankle robot, Anklebot, enabled reliable estimation of ankle mechanical impedance from the pre-swing phase through the entire swing phase to the early-stance phase. This included heel-strike and toe-off, key events in the transition from the swing to stance phase or vice versa. Time-varying ankle mechanical impedance was accurately approximated by a second order model consisting of inertia, viscosity, and stiffness in both inversion-eversion and dorsiflexion-plantarflexion directions, as observed in our previous steady-state dynamic studies. We found that viscosity and stiffness of the ankle significantly decreased at the end of the stance phase before toe-off, remained relatively constant across the swing phase, and increased around heel-strike. Closer investigation around heel-strike revealed that viscosity and stiffness in both planes increased before heel-strike occurred. This finding is important evidence of "pretuning" by the central nervous system. In addition, viscosity and stiffness were greater in the sagittal plane than in the frontal plane across all subgait phases, except the early stance phase. Comparison with previous studies and implications for clinical study of neurologically impaired patients are provided.
OBJECTIVE:To examine the correlation between syndesmotic malreduction and functional outcome.
DESIGN:Prospective evaluation of bilateral computed tomography scans and functional outcome scores.
...SETTING:Level I regional trauma center.
MATERIALS AND METHODS:From January 1, 2004, to December 31, 2006, 107 of 681 operatively treated ankle fractures (15.7%) had associated syndesmotic injuries requiring reduction and fixation. All patients available at a minimum of 2 years postindex procedure underwent clinical and radiographic examination, computed tomographic (CT) scanning of both ankles (injured and uninjured), and functional outcome scoring using the Short Form Musculoskeletal Assessment and Olerud/Molander questionnaires.
RESULTS:Sixty-eight of 107 (63.5%) syndesmotic injuries in 68 patients were available for follow-up. Twenty-seven (39%) were malreduced (rotational or translational asymmetry) when compared with the contralateral uninjured syndesmotic joint. Fifteen percent of the open syndesmotic reductions were malreduced on postoperative CT scans, whereas 44% (A/B) of the closed syndesmotic reductions were malreduced on postoperative CT scan (P = 0.11). Patients with a malreduced syndesmosis recorded significantly worse functional outcome scores (P < 0.05) on both the Short Form Musculoskeletal Assessment and Olerud/Molander questionnaires when compared with those patients whose syndesmosis had healed in anatomic alignment.
CONCLUSIONS:At a minimum of 2 years follow-up, patients with malreduced syndesmotic injuries demonstrated significantly worse functional outcome using the Short Form Musculoskeletal Assessment and Olerud/Molander questionnaires. Open reduction of the syndesmosis resulted in a substantially lower rate of malreduction when evaluated by postoperative CT scan. Based on these findings, we recommend that surgeons not only perform a direct, open visualization of the syndesmosis during the reduction maneuver, but obtain a postoperative CT scan with comparison to the contralateral extremity as well. If the syndesmosis is found to be malreduced, consideration must be given to revising the osteosynthesis.
LEVEL OF EVIDENCE:Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.
Background:
Time-dependent postoperative changes in knee joint line obliquity (KJLO) and subsequent adaptational changes in the hip and ankle joints have not been fully proven after medial open wedge ...high tibial osteotomy (MOWHTO).
Purpose:
To investigate the serial postoperative changes in KJLO and subsequent adaptational changes in the hip and ankle joints over time after MOWHTO.
Study design:
Case series, Level of evidence, 4.
Methods:
A total of 92 patients who underwent MOWHTO between April 2015 and December 2020 were evaluated. Radiographic parameters, including KJLO, ankle joint line obliquity (ALO), hip abduction angle (HAA), joint line convergence angle, weightbearing line ratio, and hip-knee-ankle angle, were analyzed in time sequence (preoperatively and 3, 6, 12, and 24 months postoperatively). Repeated-measures analysis of variance and post hoc analysis were used to demonstrate alterations and the statistical significance of KJLO and other related radiographic parameters over time.
Results:
The mean KJLO values were –1.9°, –2.1°, –2.7°, and –3.2° at 3, 6, 12, and 24 months postoperatively, respectively, indicating that there was consistent increase in valgus tilting of KJLO from 6 to 24 months (P < .001 for both 6-12 months and 12-24 months). ALO and HAA showed significant changes from 6 to 12 months (ALO, P < .001; HAA, P = .002), but not between 12 and 24 months (ALO: –3.0°, –2.7°, –1.9°, and −1.6°; HAA: –0.8°, –0.9°, –1.5°, and −1.8° at 3, 6, 12, and 24 months, respectively). The mean joint line convergence angle, weightbearing line ratio, and hip-knee-ankle angle did not change significantly from 3 months to 24 months postoperatively.
Conclusion:
There was a consistent increase in valgus tilting of the postoperative KJLO from 6 to 24 months after MOWHTO. The adaptive ALO and HAA significantly changed between 6 and 12 months and were maintained until 24 months after MOWHTO. It is necessary to consider the adaptive change when hip or ankle surgery is planned within this period.
Alterations in ankle’s articular contact mechanics serve as one of the fundamental causes of significant pathology. Nevertheless, computationally intensive algorithms and lack of bilateral ...weightbearing imaging have rendered it difficult to investigate the normative articular contact stress and side-to-side differences. The aims of our study were two-fold: 1) to determine and quantify the presence of side-to-side contact differences in healthy ankles and 2) to establish normative ranges for articular ankle contact parameters. In this retrospective comparative study, 50 subjects with healthy ankles on bilateral weight-bearing CT were confirmed eligible. Segmentation into 3D bony models was performed semi-automatically, and individualized cartilage layers were modelled based on a previously validated methodology. Contact mechanics were evaluated by using the mean and maximum contact stress of the tibiotalar articulation. Absolute and percentage reference range values were determined for the side-to-side difference. Amongst a cohort of individuals devoid of ankle pathology, mean side-to-side variation in these measurements was < 12 %, while respective differences of > 17 % talar peak stress and > 31 % talar mean stress indicate abnormality. No significant differences were found between laterality in any of the evaluated contact parameters. Understanding these values may promote a more accurate assessment of ankle joint biomechanics when distinguishing acceptable versus pathological contact mechanics in clinical practice.
We performed a systematic review and meta-analysis of modern total ankle replacements (TARs) to determine the survivorship, outcome, complications, radiological findings and range of movement, in ...patients with end-stage osteoarthritis (OA) of the ankle who undergo this procedure. We used the methodology of the Cochrane Collaboration, which uses risk of bias profiling to assess the quality of papers in favour of a domain-based approach. Continuous outcome scores were pooled across studies using the generic inverse variance method and the random-effects model was used to incorporate clinical and methodological heterogeneity. We included 58 papers (7942 TARs) with an interobserver reliability (Kappa) for selection, performance, attrition, detection and reporting bias of between 0.83 and 0.98. The overall survivorship was 89% at ten years with an annual failure rate of 1.2% (95% confidence interval (CI) 0.7 to 1.6). The mean American Orthopaedic Foot and Ankle Society score changed from 40 (95% CI 36 to 43) pre-operatively to 80 (95% CI 76 to 84) at a mean follow-up of 8.2 years (7 to 10) (p < 0.01). Radiolucencies were identified in up to 23% of TARs after a mean of 4.4 years (2.3 to 9.6). The mean total range of movement improved from 23° (95% CI 19 to 26) to 34° (95% CI 26 to 41) (p = 0.01). Our study demonstrates that TAR has a positive impact on patients' lives, with benefits lasting ten years, as judged by improvement in pain and function, as well as improved gait and increased range of movement. However, the quality of evidence is weak and fraught with biases and high quality randomised controlled trials are required to compare TAR with other forms of treatment such as fusion.
An ankle joint stretching device controlled by healthy-side ankle movements was developed for self-rehabilitation. Physical therapists treat their patients to prevent a subject ankle joint’s ...contracture and improve their walking function. However, sufficient rehabilitation therapy cannot be performed because of the labor demands of ankle joint rehabilitation. There has long been a demand for a self-rehabilitation system to reduce the amount of labor required, with the rehabilitation system operated by a physical therapist using a machine. Self-rehabilitation has not yet been realized. By stretching the affected ankle through the movement of the ankle on the healthy side, a self-rehabilitation device that can be used according to the will of the patient can be developed. An experiment confirmed that the device can realize affected-side ankle joint stretching by moving a foot plate connected to a linear actuator using the angle of the healthy-side ankle joint as a trigger. Ankle joint rotation angles of the affected and healthy sides were measured using two acceleration sensors. Compared with the previously used button-push-type control, healthy-side control can realize a smooth and stable affected-side sole-pushing procedure. The proposed system, which does not require operation by a physical therapist during treatment, makes self-rehabilitation of the ankle joint possible.
•Posterior malleolar fracture morphology evaluated with computed tomography and not with - unreliable - plain radiographs.•Posterior malleolar fracture morphology determines outcome in rotational ...type ankle fractures.•Posterior malleolar ankle fractures with medial extension are associated with significantly poorer functional outcome scores at two years postoperative.•Undertake computed tomography imaging when a posterior malleolar ankle fracture is expected.•Base treatment decision not on the fracture-fragment-size threshold, but merely on fracture morphology and fragment pathoanatomy.
Rotational type ankle fractures with a concomitant fracture of the posterior malleolus are associated with a poorer clinical outcome as compared to ankle fractures without. However, clinical implications of posterior malleolar (PM) fracture morphology and pattern have yet to be established. Many studies on this subject report on fragment size, rather than fracture morphology based on computed tomography (CT). The overall purpose of the current study was to elucidate the correlation of PM fracture morphology and functional outcome, assessed with CT imaging and not with –unreliable- plain radiographs.
Between January 2010 and May 2014, 194 patients with an operatively (ORIF) treated ankle fracture, were prospectively included in the randomized clinical EF3X-trial at our Level-I trauma center. The current study retrospectively included 73 patients with rotational type ankle fractures and concomitant fractures of the posterior malleolus. According to the CT-based Haraguchi fracture morphology, all patients were divided into three groups: 20 Type I (large posterolateral-oblique), 21 Type II (transverse medial-extension) and 32 Type III (small-shell fragment). At 12 weeks, 1 year and 2 years postoperatively the Foot and Ankle Outcome Scores (FAOS) and SF-36 scores were obtained, with the FAOS domain scores at two years postoperative as primary study outcome. Statistical analysis included a multivariate regression and secondary a mixed model analysis.
Haraguchi Type II PM ankle fractures demonstrated significantly poorer outcome scores at two years follow-up compared to Haraguchi Types I and III. Mean FAOS domain scores at two years follow-up showed to be significantly worse in Haraguchi Type II as compared to Type III, respectively: Symptoms 48.2 versus 61.7 (p = 0.03), Pain 58.5 versus 84.4 (p < 0.01), Activities of Daily Living (ADL) 64.1 versus 90.5 (p < 0.01).
Posterior malleolar ankle fractures with medial extension of the fracture line (i.e. Haraguchi Type II) are associated with significantly poorer functional outcomes. The current dogma to fix PM fractures that involve at least 25–33% of the tibial plafond may be challenged, as posterior malleolar fracture pattern and morphology - rather than fragment size - seem to determine outcome.
Abstract Posterior malleolar fractures are relatively common and usually result from rotational ankle injuries. Although treatment of associated lateral and medial structures is well established, ...several controversies exist in the management of posterior malleolus fractures. We performed a systematic review of the current published data with regard to the diagnosis, management, and prognosis of posterior malleolus fractures. A total of 33 studies (8 biomechanical and 25 clinical) with >950 patients were reviewed. The outcome of ankle fractures with posterior malleolar involvement was poor; however, the evidence was not enough to prove that the size of the posterior malleolus affects the outcome. Significant heterogeneity was noted in the cutoff size of the posterior malleolar fragment in determining management. The outcome was related to other factors, such as fracture displacement, congruency of the articular surface, and residual tibiotalar subluxation. Indirect evidence showed that large fracture fragments were associated with fracture dislocations and ankle instability and, thus, might require surgical fixation. We have concluded that the evidence to prove that the size of the posterior malleolar affects the outcome of ankle fractures is not enough, and the decision to treat these fractures should be determined by other factors, as stated previously.
The majority of the ankle osteoarthritis cases are posttraumatic and affect younger patients with a longer projected life span. Hence, joint-preserving surgery, such as supramalleolar osteotomy ...becomes popular among young patients, especially those with asymmetric arthritis due to alignment deformities. However, there is a lack of biomechanical studies on postoperative evaluation of stress at ankle joints. We aimed to construct a verifiable finite element model of the human hindfoot, and to explore the effect of different osteotomy parameters on the treatment of varus ankle arthritis.
The bones of the hindfoot are reconstructed using normal CT tomography data from healthy volunteers, while the cartilages and ligaments are determined from the literature. The finite element calculation results are compared with the weight-bearing CT (WBCT) data to validate the model. By setting different model parameters, such as the osteotomy height (L) and the osteotomy distraction distance (h), the effects of different surgical parameters on the contact stress of the ankle joint surface are compared.
The alignment and the deformation of hindfoot bones as determined by the finite element analysis aligns closely with the data obtained from WBCT. The maximum contact stress of the ankle joint surface calculated by this model increases with the increase of the varus angle. The maximum contact stresses as a function of the L and h of the ankle joint surface are determined.
The relationship between surgical parameters and stress at the ankle joint in our study could further help guiding the planning of the supramalleolar osteotomy according to the varus/valgus alignment of the patients.
•Quantitative study of the stress concentration/peak position in supramalleolar osteotomy.•A nonlinear finite element hindfoot model with major ligaments and contacting properties.•The model is validated by comparing the simulation results to the weight-bearing CT data.
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