Ontogenic transformation of the ankle from the initial mediolateral arrangement of the calcaneus and talus: A histological study of human embryos and early fetuses.

The human calcaneus is robust and provides a prominent heel for effective bipedal locomotion, although the adjacent talus has no muscle attachments. However, there is incomplete information about the morphological changes in these prominent bones during embryo development. We examined serial histological sections of 23 human embryos and early-term fetuses (approximately 5-10 weeks' gestational age [GA]). At a GA of 5 weeks, the precartilage talus was parallel to and on the medial side of the calcaneus, which had a prolate spheroid shape and consisted of three masses. At a GA of 6 weeks, the cartilaginous talus extended along the proximodistal axis, and the tuber calcanei became long and bulky, with a small sustentaculum talus at the "distal" side. At a GA of 6 to 8 weeks, the sustentaculum had a medial extension below the talus so that the talus "rode over" the calcaneus. In contrast, the talus had a more complex shape, depending on the growth of adjacent bones. At a GA of 9 to 10 weeks, the talus was above the calcaneus, but the medial part still faced the plantar subcutaneous tissue because of the relatively small sustentaculum. Therefore, the final morphology appeared after an additional several weeks. Muscle activity seemed to facilitate growth of the tuber calcanei, but growth of the other parts of calcaneus, including the sustentaculum, seemed to depend on active proliferation at the different sites of cartilage. Multiple tendons and ligaments seemed to fix the talus so that it remained close to the calcaneus.

Low annual revision rate in ankle distraction for ankle osteoarthritis: A systematic review and meta-analysis.

PURPOSE: Ankle osteoarthritis severely impacts patients' mental and physical quality of life. Besides total ankle replacement and ankle arthrodesis, ankle distraction has been shown to be a promising alternative. The primary aim of the present study was to determine the annual revision rates (ARRs) after ankle distraction. The secondary aim was to obtain an overview of patient-reported outcome measures and functional outcomes. METHODS: A literature search until November 2023 was performed. Methodological quality was assessed using the methodological index for non-randomised studies criteria. Primary outcome was the ARR which was log-transformed and pooled using a random effects model. Secondary outcomes were pooled using a simplified pooling technique and included the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale (AOFAS), range of motion (ROM) and post-operative complications. RESULTS: The literature search resulted in 287 articles, of which 10 studies, comprising 602 patients, were included. The patients had a pooled mean age of 47 years (range of means: 40-68) and a mean follow-up of 35 months (range of means: 24-48). The overall methodological quality was moderate to fair. The pooled ARR after ankle distraction was 4% (95% confidence interval [CI], 3%-7%). Pooling of AOFAS showed mean 26-point improvement (from 54 to 80). Additionally, ROM dorsiflexion improved at 5°, and the plantarflexion remained at 31°. The overall complication rate was 41% (95% CI, 35%-48%), of which 77% (95% CI, 67%-85%) were pin-tract infections. CONCLUSION: Ankle distraction results in an ARR of 4% (95% CI, 3%-7%) with clinically relevant improved AOFAS scores. The overall complication rate is 41% and is mainly attributable to treatable pin-tract infections (77% of recorded complications). LEVEL OF EVIDENCE: Level IV, Systematic Review and Meta-Analysis.

Research on a Calculation Model of Ankle-Joint-Torque-Based sEMG.

The purpose of this article is to establish a prediction model of joint movements and realize the prediction of joint movemenst, and the research results are of reference value for the development of the rehabilitation equipment. This will be carried out by analyzing the impact of surface electromyography (sEMG) on ankle movements and using the Hill model as a framework for calculating ankle joint torque. The table and scheme used in the experiments were based on physiological parameters obtained through the model. Data analysis was performed on ankle joint angle signal, movement signal, and sEMG data from nine subjects during dorsiflexion/flexion, varus, and internal/external rotation. The Hill model was employed to determine 16 physiological parameters which were optimized using a genetic algorithm. Three experiments were carried out to identify the optimal model to calculate torque and root mean square error. The optimized model precisely calculated torque and had a root mean square error of under 1.4 in comparison to the measured torque. Ankle movement models predict torque patterns with accuracy, thereby providing a solid theoretical basis for ankle rehabilitation control. The optimized model provides a theoretical foundation for precise ankle torque forecasts, thereby improving the efficacy of rehabilitation robots for the ankle.

Analyzing Learning Curve Effects: Total Ankle Replacement Design Switch and Long-Term Survival.

Different aspects of the learning curve in total ankle replacement (TAR) have been studied in the short to mid-term, with 30 cases often considered critical. However, its impact on long-term (10- and 15-year) survival remains unclear. Therefore, we retrospectively analyzed 77 consecutive TARs performed by one orthopedic surgeon. The main outcome was long-term survival between cases 1-30 and 31-77 using the Kaplan-Meier with Competing Risk Analyses. Secondarily, we used Moving Average Method with LOESS regression to confirm the learning curve based on the perioperative complications. Thirdly, associations between perioperative complications and operation time on long-term survival were assessed using Cox proportional hazard models. The 10-year survival of cases 1-30 was 89.9% (95% CI 70.4-96.5), and of 31-77, 92.4% (95% CI 7745- 97.5) (p = .58). The 15-year survival was 81.8% (95% CI 59.5-91.8) and 74.8% (95% CI 52.4-86.6), respectively (p = .97). The long-term survival rate for the TAR that endured perioperative complication was 96.70% (95% CI 90.28-103.12), and for the uncomplicated TAR 87.50% (95% CI 77.12-97.88%) (p = .24). Operating time nor occurrence of perioperative fractures were significantly associated with long-term survival (p = .11 and 0.26, respectively). However, moving average method revealed a significant decreasing trend with a cut-off value of 33 procedures regarding the marginal probability of perioperative osseous complications (p < .01). In conclusion, surgeons should note a learning curve when adapting arthroplasty procedures. After the prosthesis design switch, the learning curve regarding perioperative osseous complications was confirmed at 33 TAR. The switch did not affect long-term survival.

[Tibiotalocalcaneal arthrodesis for end-stage ankle and hindfoot arthropathy: Short- and mid-term clinical outcomes].

OBJECTIVE: To analyze the clinical data of patients with end-stage ankle and hindfoot arthropathy who underwent tibiotalocalcaneal (TTC) arthrodesis by the same surgeon, explore the short- and mid-term clinical results, complications and functional improvement, and discuss the clinical prognosis and precautions of TTC arthrodesis. METHODS: Retrospective analysis was made on the clinical data of 40 patients who underwent TTC arthrodesis by the same surgeon from March 2011 to December 2020. In this study, 23 males and 17 females were included, with an average age of (49.1±16.0) years. All the patients underwent unilateral surgery. The clinical characteristics, imaging manifestations, main diagnosis and specific surgical techniques of the patients were recorded. The clinical outcomes were evaluated by comparison of the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and visual analogue scale (VAS) between pre-operation and at the last follow-up. The fusion healing time, symptom improvement (significant improvement, certain improvement, no improvement or deterioration) and postoperative complications were also recorded. RESULTS: The median follow-up time was 38.0 (26.3, 58.8) months. The preoperative VAS score was 6.0 (4.0, 7.0), and the AOFAS score was 33.0 (25.3, 47.3). At the last follow-up, the median VAS score was 0 (0, 3.0), and the AOFAS score was 80.0 (59.0, 84.0). All the significantly improved compared with their preoperative corresponding values (P < 0.05). There was no wound necrosis or infection in the patients. One patient suffered from subtalar joint nonunion, which was syphilitic Charcot arthropathy. The median bony healing time of other patients was 15.0 (12.0, 20.0) weeks. Among the included patients, there were 25 cases with significant improvement in symptom compared with that preoperative, 8 cases with certain improvement, 4 cases with no improvement, and 3 cases with worse symptoms than that before operation. CONCLUSION: TTC arthrodesis is a reliable method for the treatment of the end-stage ankle and hindfoot arthropathy. The function of most patients was improved postoperatively, with little impact on daily life. The causes of poor prognosis included toe stiffness, stress concentration in adjacent knee joints, nonunion and pain of unknown causes.

Ankle arthroscopy does not elevate complication rates in ankle fractures.

INTRODUCTION: Ankle fractures rank as the second most common lower limb fractures, and surgical intervention is essential for unstable ankle fractures. The use of ankle arthroscopy in such cases offers several advantages. This study aim is to assess whether arthroscopy influenced on complication rates in 171 ankle fractures treated with arthroscopic assistance. METHODS: This retrospective epidemiological analysis encompassed adult ankle fractures between December 2018 and December 2021. Initially, 173 patients were considered, but two were excluded, leaving a final sample of 171 patients. Postoperative complications were categorized as major or minor. RESULTS: The study included 171 patients with surgically treated ankle fractures assisted by arthroscopy, comprising 76 females and 95 males, with an average age of 41.9 years. Syndesmosis injuries were treated in all diagnosed cases (55.0%), and deltoid ligament injuries received attention when identified (33.7%). Arthroscopic techniques were preferred over open techniques (47.4%). Ten patients experienced complications, consisting of 2 major and 8 minor complications (5.8%). DISCUSSION: Our study's epidemiological findings align with prior literature, demonstrating that intra-articular injuries accompany 63% to 79% of ankle fractures. Arthroscopy allows for both diagnosis and treatment within the same procedure, including joint lavage to reduce inflammation. We diagnosed 57 deltoid injuries and identified a statistical relationship between chondral, syndesmotic, and deltoid ligament injuries. Infection is a common complication in ankle fracture surgery, with rates ranging from 1.44% to 16%. Our study yielded a 5.8% complication rate, comprising 1.2% major and 4.6% minor complications. Patients undergoing ORIF with arthroscopic assistance had a lower prevalence of infection. CONCLUSION: The use of arthroscopic assistance in the surgical treatment of ankle fractures does not increase the overall complication rate. LEVEL OF EVIDENCE: IV.

Numerical simulations of the effect of lateral malleolus fracture malunion on ankle biomechanics: Different offset directions and offsets.

INTRODUCTION: Ankle fractures account for approximately 10 % of all fractures. Approximately 5-68 % of patients with ankle fractures may suffer from malunion. Besides, suboptimal reduction of fracture fragments can affect the biomechanics of the ankle joint, ultimately leading to damage to the ankle joint. However, there are certain controversies over the conclusion of previous cadaveric studies. METHODS: In this study, a three-dimensional model of the ankle joint was established based on CT image data. In addition, the effects of backward offset (1-2 mm) and outward offset (0.5-1 mm) of the fracture fragment on the contact area, contact pressure, and ligament force of the ankle joint were investigated via the finite element method. Moreover, lateral malleolus fracture malunion in five ankle positions (neutral, 10° dorsiflexion, 10° plantarflexion, 20° dorsiflexion, and 20° plantarflexion) was investigated. RESULTS: This model predicted an overall increased contact area in the ankle joint in patients with lateral malleolus fracture malunion compared with the normal ankle joint. The results demonstrated that the outward offset had a more significant effect than the backward one. The larger the dorsiflexion-plantarflexion angle, the more pronounced the effect of malunion. Further, an outward offset can cause the fibula to lose its function. CONCLUSION: Post-traumatic osteoarthritis occurs under the action of unaccustomed cartilage forces due to altered tibial talar joint contact patterns, rather than increased contact pressure reported in previous studies. Malunion leads to an increase or decrease in force on the affected ligament, while the cause of malunion can be envisioned based on a decrease in the force on the ligaments.

Comparison of visibility in needle arthroscopy of the ankle according to surgical experience: A cadaveric study.

BACKGROUND: Literature regarding the feasibility of inexperienced surgeons using needle arthroscopy is limited. The present study aimed to clarify the feasibility of performing ankle needle arthroscopy for inexperienced surgeons. METHODS: Diagnostic needle arthroscopy was performed for 10 cadaveric ankles by two surgeons with different levels of experience in ankle arthroscopy (inexperienced and expert surgeons). The visibility of arthroscopy was assessed based on a 15-point checklist and compared between surgeons. In addition, iatrogenic articular cartilage injury created by the inexperienced surgeon was investigated. RESULTS: The number of visible points was significantly larger for the expert surgeon than for the inexperienced surgeon (14.1 ± 1.0 vs. 13.7 ± 1.0, P = 0.035). The location of cartilage injury was greatest on the medial talar dome when viewing from the anteromedial portal at a rate of 30%. CONCLUSION: Ankle needle arthroscopy may be an option for surgeons in the future, however, differences in surgeon experience may impact effective visualization.

[Therapy of degenerative changes in the ankle joint with US-guided linear hyaluronic acid injections. A review].

The article discusses the issue and our own experience of local therapy for osteoarthritis of the ankle joint with injections of linear hyaluronic acid under ultrasound navigation. Since the ankle joint is difficult in terms of surgical treatment in general and endoprosthetics in particular, a course of intra-articular injection of 1% Flexotron® Forte hyaluronate, especially in the early stages of dystrophic changes in cartilage, is a promising method for relieving pain, chondroprotection and preserving the biomechanics of the joint, and ultrasound navigation when performing manipulation, it ensures the most accurate introduction of the drug into the joint cavity.

The value of bone SPECT/CT in evaluation of foot and ankle arthrodesis and adjacent joint secondary osteoarthritis.

OBJECTIVE: To evaluate the value of SPECT/CT (single photon emission computed tomography/computed tomography) in foot and ankle arthrodesis and development of secondary osteoarthritis in the adjacent joints. MATERIALS AND METHODS: SPECT/CT of 140 joints in the foot and ankle (34 upper ankle (UA), 28 lower ankle (LA), 27 talonavicular (TN), 12 calcaneo-cuboidal (CC), and 39 other smaller joints after arthrodesis in 72 patients were evaluated retrospectively regarding fusion grade in CT (0 = no fusion, 1 = < 50% fusion, 2 = > 50% fusion, 3 = complete fusion) and radiotracer uptake (0 = no uptake, 1 = mild uptake, 2 = moderate uptake, 3 = high uptake) on SPECT/CT. Severity of osteoarthritis (1 = mild, 2 = moderate, 3 = severe) and radiotracer uptake grade in adjacent joints was also assessed. In 54 patients, clinical information about interventions in the follow-up was available. RESULTS: According to the SPECT/CT, arthrodesis was successful (grade 2 or 3 CT fusion and grade 0 or 1 uptake) in 73% (25/34) of UA joints, 71% (20/28) of LA joints, 67% (18/27) TN, 100% (12/12) CC joints, and 62% (24/39) of other smaller joints. In 12 joints, there were discrepant findings in SPECT/CT (fusion grade 2 and uptake grade 2 or 3 (n = 9); or, fusion grade 0 or 1 and uptake grade 1 (n = 3)). The fusion rate 6-12 months after arthrodesis was 42% (14/33), 59% (20/34) after 13-24 months, and 89% (65/73) after more than 24 months, respectively. Average radiotracer uptake in arthrodesis decreased with age: 6-12 months: 1.60, 12-24 months: 1.32, > 24 months: 0.38. There was a significant negative correlation between radiotracer uptake grade and CT fusion grade. Osteoarthritis was observed in 131 adjacent joints. During the post scan follow-up, additional arthrodeses were performed in 33 joints, of which 11 joints were re-arthrodesis and 22 were new arthrodeses in osteoarthritic adjacent joints. All these 11 joints with failed arthrodesis had grade 0 of CT fusion and grade 2 or 3 of radiotracer uptake. All 22 adjacent joints with osteoarthritis, which subsequently underwent arthrodesis, had grade 2 or 3 radiotracer uptake, and the primary arthrodesis joints were healed and fused in all these cases. CONCLUSION: Bone SPECT/CT is a valuable hybrid imaging tool in the evaluation of foot and ankle arthrodesis and gives additional useful information about the development of secondary osteoarthritis in the adjacent joints with higher value for the assessment of secondary osteoarthritis. A practical four-type classification ('Lucerne Criteria') combining metabolic and morphologic SPECT/CT information for evaluation of arthrodesis joints has been proposed.

Structural changes after ankle joint distraction in haemophilic arthropathy: an explorative study investigating biochemical markers and 3D joint space width.

INTRODUCTION: Ankle joint distraction (AJD) is a promising treatment for patients with severe haemophilic ankle arthropathy (HAA). However, some patients showed no clinical improvement after AJD and these differences may be related to structural differences. AIM: Primarily to quantify the structural changes after AJD in patients with HAA by the use of 3D joint space width (JSW) measurements and biochemical markers and secondarily to correlate these findings with clinical pain/function. METHODS: Patients with haemophilia A/B who underwent AJD were included for this study. Bone contours on MRI (performed before and 12 and 36 months after AJD) were drawn manually and percentage change in JSW was calculated. Blood/urine (before and 6, 12, 24 and 36 months after AJD) was collected for biomarker measurement (COMP, CS846, C10C, CALC2, PRO-C2, CTX-II) and combined indexes of markers were calculated. Mixed effects models were used for analyses on group level. Structural changes were compared with clinical parameters. RESULTS: Eight patients were evaluated. On group level, percentage changes in JSW showed a slight decrease after 12 months followed by a non-statistically significant increase in JSW after 36 months compared to baseline. Biochemical marker collagen/cartilage formation also showed an initial decrease, followed by a trend towards net formation 12, 24 and 36 months after AJD. On individual patient level, no clear correlations between structural changes and clinical parameters were observed. CONCLUSION: Cartilage restoration activity on group level in patients with HAA after AJD was in concordance with clinical improvements. Correlating structural modifications with clinical parameters in the individual patient remains difficult.

3-D joint space mapping at the ankle from weight-bearing CT: reproducibility, repeatability, and challenges for standardisation.

OBJECTIVES: We present a 3-D approach to joint space width (JSW) measurement across the ankle from weight-bearing CT (WBCT) to demonstrate inter-operator reproducibility, test-retest repeatability, and how differences in angulation affect ankle JSW distribution. METHODS: One side from repeat WBCT imaging of both feet and ankles was analysed from 23 individuals as part of their routine clinical care pathway. Joint space mapping was performed at four facets across the talus: talonavicular, talar dome and medial gutter (dome-medial), lateral gutter, and posterior subtalar. Inter-operator reproducibility was calculated for two users, while test-retest repeatability was calculated by comparing the two visits, both presented as Bland-Altman statistics. Statistical parametric mapping determined any significant relationships between talocrural joint space angulation and 3-D JSW distribution. RESULTS: The average ± standard deviation interval between imaging was 74.0 ± 29.6 days. Surface averaged bias ± limits of agreement were similar for reproducibility and repeatability, the latter being: talonavicular 0.01 ± 0.26 mm, dome-medial 0.00 ± 0.28 mm, lateral gutter - 0.02 ± 0.40 mm, and posterior subtalar 0.02 ± 0.34 mm. Results are presented as 3-D distribution maps, with optimum test-retest repeatability reaching a smallest detectable difference of ± 0.15 mm. CONCLUSIONS: Joint space mapping is a robust approach to 3-D quantification of JSW measurement, inter-operator reproducibility, and test-retest repeatability at the ankle, with sensitivity reaching a best value of ± 0.15 mm. Standardised imaging protocols and optimised metal artefact reduction will be needed to further understand the clinical value of these 3-D measures derived from WBCT. CLINICAL RELEVANCE STATEMENT: Weight-bearing computed tomography is an increasingly important tool in the clinical assessment of orthopaedic ankle disorders. This paper establishes the performance of measuring 3-D joint space width using this technology, which is an important surrogate marker for severity of osteoarthritis. KEY POINTS: • Joint space width values and error metrics from across the ankle measured from weight-bearing CT can be presented as 3-D maps that show topographic variation. • The best sensitivity for detecting meaningful change in 3-D joint space width at the ankle was ± 0.15 mm, a value less than the isotropic imaging voxel dimensions. • Standardised imaging protocols and optimised metal artefact reduction will be needed to understand the clinical value of 3-D measures from weight-bearing CT.

Study on the effect of self-made fracture positioning compression guide device for posterior malleolus fracture surgery: Medical prevention.

To evaluate the effectiveness of a self-designed pressure-guided fracture positioning device, a prospective study was conducted in patients with posterior ankle fractures undergoing surgery using the device. Twenty-seven cases of ankle joint fracture with posterior malleolus fracture were treated by surgery. In the process of fixing posterior malleolus fracture, a self-designed fracture positioning compression guide device was used to fix posterior malleolus bone by anterior and posterior approaches. Postoperative CT images were used to assess the fixation position as well as length of the screw and the compression of the fracture. All patients had healed ankle fractures, and the anterior-posterior screws were fixed in the central area of the posterior malleolus. Posterior malleolus fragment displacement was <2 mm. The screw effectively secured the cortex beyond the length of the posterior malleolus cortex by no more than two threads. The good rate of ankle joint function was 85.16%. Compared to traditional surgical techniques, minimally invasive fixation using the self-designed positioning compression guide device has several advantages, including smaller trauma, faster postoperative recovery, and improved patient satisfaction. The device also provides the surgeon with greater control and precision during the surgical procedure, which can contribute to better surgical outcomes.

Effects of Conservative Interventions on Static and Dynamic Balance in Individuals With Chronic Ankle Instability: A Systematic Review and Meta-analysis.

OBJECTIVE: To determine which conservative interventions are effective for static and dynamic balance in patients with chronic ankle instability (CAI). DATA SOURCES: PubMed, Cochrane Library, Web of Sciences, and CINAHL databases were searched up to March 20, 2022. STUDY SELECTION: Randomized controlled trials investigating the effects of conservative interventions on static and/or dynamic balance in patients with CAI compared with those of different conservative interventions or controls were included. DATA EXTRACTION: Two independent reviewers extracted the data. Certainty of the evidence was assessed using the GRADE approach. DATA SYNTHESIS: Forty-eight studies (1906 participants) were included. Whole-body vibration training (WBVT) was significantly more effective than controls for both static (standardized mean difference, 1.13; 95% confidence interval [CI], 0.58-1.68; moderate-certainty evidence) and dynamic balance (0.56; CI, 0.24-0.88; low-certainty evidence). Balance training (BT) and joint mobilization were significantly more effective than controls for dynamic balance (0.77; CI, 0.41-1.14; and 0.75; CI, 0.35-1.14, respectively), but not for static balance (very low to low-certainty evidence). Adding other interventions to BT had no significant effect on either type of balance compared with that of BT alone (moderate to low-certainty evidence). Strength training (ST) and taping had no significant effect on either type of balance (very low- to low-certainty evidence). Multimodal interventions were significantly effective in improving dynamic balance (0.76; CI, 0.32-1.20; low-certainty evidence). Adding transcranial direct current stimulation to ST was significantly more effective for dynamic balance than ST (0.81; CI, 0.08-1.53; moderate-certainty evidence). The effects on balance were not significantly different among BT, ST, and WBVT (very low- to low-certainty evidence). CONCLUSIONS: The significantly effective interventions reviewed may be treatment options for balance impairments associated with CAI. However, interventions should be chosen carefully, as much of the certainty of evidence is very low to low.

Acute passive stretching has no effect on gastrocnemius medialis stiffness in children with unilateral cerebral palsy.

PURPOSE: The aim of this study was to investigate the effects of an acute high-intensity, long-duration passive stretching session of the plantar flexor muscles, on maximal dorsiflexion (DF) angle and passive stiffness at both ankle joint and gastrocnemius medialis (GM) muscle levels in children with unilateral cerebral palsy (CP). METHODS: 13 children [mean age: 10 years 6 months, gross motor function classification system (GMFCS): I] with unilateral CP underwent a 5 min passive stretching session at 80% of maximal DF angle. Changes in maximal DF angle, slack angle, passive ankle joint and GM muscle stiffness from PRE- to POST-intervention were determined during passive ankle mobilization performed on a dynamometer coupled with shear wave elastography measurements (i.e., ultrasound) of the GM muscle. RESULTS: Maximal DF angle and maximal passive torque were increased by 6.3° (P < 0.001; + 50.4%; 95% CI 59.9, 49.9) and 4.2 Nm (P < 0.01; + 38.9%; 95% CI 47.7, 30.1), respectively. Passive ankle joint stiffness remained unchanged (P = 0.9; 0%; 95% CI 10.6, - 10.6). GM muscle shear modulus was unchanged at maximal DF angle (P = 0.1; + 34.5%; 95% CI 44.7, 24.7) and at maximal common torque (P = 0.5; - 4%; 95% CI - 3.7, - 4.3), while it was decreased at maximal common angle (P = 0.021; - 35%; 95% CI - 11.4, - 58.5). GM slack angle was shifted in a more dorsiflexed position (P = 0.02; + 20.3%; 95% CI 22.6, 18). CONCLUSION: Increased maximal DF angle can be obtained in the paretic leg in children with unilateral CP after an acute bout of stretching using controlled parameters without changes in passive stiffness at joint and GM muscle levels. CLINICAL TRIAL NUMBER: NCT03714269.

A rare case of an intra-articular true lipoma of the ankle.

BACKGROUND: Most of the foot and ankle soft tissue tumors are benign. Although lipomas are the most common soft tissue tumors, intra-articular lipomas are an extremely rare entity. The majority of described cases of intra-articular lipomas occur in the knee joint. In particular, an intra-articular true lipoma of the ankle has not been reported. CASE PRESENTATION: We report the case of a 45-year-old woman who presented with a progressively growing ankle mass over 5 years, which started to restrict the range of motion. It was not preceded by any trauma or sports activity. On examination, a non-tender firm mass was evident on the lateral aspect of the right ankle joint with no signs of inflammation. It was non-compressible, non-mobile, and did not transilluminate. The clinical diagnosis was probable for a soft tissue ganglion. A radiograph revealed a soft tissue opacity over the anterolateral aspect of the tibiotalar joint. Magnetic resonance imaging (MRI) demonstrated a well-defined, multilobulated, encapsulated lesion located at the lateral aspect of the tibiotalar joint; with intra- and extra-articular components and an analogous signal intensity to fat. The patient underwent surgical excision of the tumor, and the histopathological examination showed mature adipose tissue representing an intra-articular lipoma. At the follow-up visit, the patient had complete resolution of symptoms and no active complaints. CONCLUSION: An intra-articular true lipoma of the ankle is an extremely rare tumor. MRI is an invaluable diagnostic tool to make a reliable diagnosis of intra-articular masses.

Coronal and sagittal alignment of ankle joint is significantly affected by high tibial osteotomy.

PURPOSE: Changes in coronal and sagittal alignment of the knee joint after HTO have been reported in several previous studies. However, only few of them investigated the changes only on coronal alignment of the ankle joint. The purpose of this study was to investigate changes in both coronal and sagittal alignment of the ankle joint after HTO. METHODS: 46 patients (49 cases) who underwent HTO were retrospectively analyzed. Preoperative and postoperative lower extremity scanogram and EOS imaging system were investigated. The hip-knee-ankle (HKA) angle, medial proximal tibial angle (MPTA), and knee tibia plafond angle (KTPA) were measured by scanogram to evaluate coronal alignment of the knee. Tibial anterior surface angle (TAS), talar tilt (TT), tibial plafond inclination (TPI), and ankle joint axis point on the weight-bearing-line (AAWBL) ratio were measured by scanogram to investigate coronal alignment of the ankle. Knee lateral ankle surface angle (KLAS) and tibial lateral surface angle (TLS) were measured by EOS to evaluate sagittal alignment of the ankle. RESULTS: Varus alignment of the knee was corrected by significant change of the HKA angle (5.8 ± 3.1° vs. - 2.1 ± 2.8°, p < 0.001), MPTA (85.7 ± 2.9° vs. 91.7 ± 3.3°, p < 0.001), and KTPA (5.0 ± 3.5° vs. - 2.1 ± 4.2°, p < 0.001) after HTO. Regarding the ankle coronal alignment, there was significant change in TPI (3.9 ± 3.4° vs. - 0.9 ± 3.8°, p < 0.001) and AAWBL ratio (45.5 ± 14.7% vs. 61.6 ± 13.3%, p < 0.001). In sagittal alignment of the ankle, KLAS (4.5 ± 3.1° vs. 7.7 ± 3.7°, p < 0.001) significantly increased. Among the variables, the amount of correction in AAWBL ratio (R = 0.608, p < 0.01) showed strongest relationship with tibial correction angle. CONCLUSION: Based on the present study, coronal and sagittal alignment of ankle joint was significantly affected by HTO. After HTO, AAWBL ratio increased due to lateralization of the ankle joint axis, and KLAS increased due to increased posterior tibial slope. LEVEL OF EVIDENCE: III.

Changes in ankle and hip joints following medial opening-wedge high tibial osteotomy affect knee joint line obliquity.

PURPOSE: This study aimed to measure the change in knee joint line obliquity (KJLO) and the changes in radiologic parameters of the ankle and hip joints after medial opening-wedge high tibial osteotomy (MOWHTO), and to evaluate the correlation and causal relationship between these parameters. METHODS: This study evaluated 109 patients who underwent MOWHTO between April 2015 and December 2021. Radiologic parameters, including KJLO, medial proximal tibial angle (MPTA), ankle joint line obliquity (AJLO), and hip abduction angle (HAA), were analysed before and 1 year after MOWHTO. Multiple linear regression analysis was used to identify independent variables that significantly affected the change in KJLO after MOWHTO. Receiver operating characteristic (ROC) analysis was used to evaluate the cutoff value for a change in KJLO that exceeded 5° postoperatively, and the predicting values of radiologic parameters. RESULTS: Multiple linear regression analysis showed that changes in MPTA, AJLO, and HAA (ß = 0.440, P < 0.001; ß = - 0.310, P < 0.001; ß = 0.164, P = 0.035, respectively) were predictors of the change in KJLO after MOWHTO. ROC analysis showed that the threshold value for a change in KJLO which exceeded 5° postoperatively was 4.6° (66.7% sensitivity, 63.8% specificity, P = 0.025). Moreover, ROC curves for predicting a change in KJLO of > 4.6° showed that the AUC was significantly higher for the change in MPTA than that of the other two parameters (P = 0.011 for AJLO and P < 0.001 for HAA). CONCLUSION: MOWHTO increases the KJLO by valgization of the proximal tibia and causes hip adduction and ankle valgization. The postoperative ankle valgization after MOWHTO could reduce the increase in KJLO, counteracting the effects of proximal tibial valgization and hip adduction. Therefore, the effects of the hip and ankle joints should be considered to achieve an optimal KJLO and satisfactory clinical outcomes after MOWHTO. LEVEL OF STUDY: Cohort study, IV.

Referential values for lower limb flexibility in healthy children and adolescents in Japan: A five-year cross-sectional study.

BACKGROUND: Lower limb flexibility (LLF) is an essential motor function. However, assessing LLF during adolescence is difficult because of the influence of marked physical changes. We, therefore, assessed LLF and investigated the relationship between LLF and sex and age in healthy children and adolescents. METHODS: We conducted a five-year cross-sectional study with students aged 8-14 years at a single school in Japan. We evaluated the heel-buttock distance (HBD), straight leg raising angle (SLRA), and dorsiflexion angle of the ankle joint (DFA) at the beginning of each year. We conducted a comparative analysis on the performance of the HBD, SLRA, and DFA techniques, stratified by both sex and age. The statistical significance of observed differences was assessed through the application of Mann-Whitney U and Kruskal-Wallis tests. Furthermore, we analyzed the effects of sex, age, height, and weight on LLF using a multivariable linear regression model. RESULTS: Of the 4221 initial study participants, 3370 were analyzed. Mean HBD, SLRA, and DFA values were 1.6 cm, 77.0°, and 15.7°, respectively. Girls showed significantly higher HBD and lower SLRA and DFA values than boys and 14-year-olds (p < 0.01). Median HBD value for girls was 0 cm, whereas for boys, it exceeded 0 cm after age 13. The median SLRA value for girls was 80-85°, while for boys, it was 70-75°. The median DFA value for girls was 15-19°, and for boys, it was 12-15°. A multivariable linear regression model indicated that boys had significantly greater tightness than girls (p < 0.01). CONCLUSIONS: The reference values of HBD, SLRA, and DFA differed according to age and sex. Furthermore, we showed that sex differences were significantly associated with LLF. Data in this study provide the reference value for assessing LLF in children and adolescents.

Variation in the anterior talofibular ligament and the impact of sex, height, weight, and age.

The anterior talofibular ligament (ATFL) is one of the lateral ankle ligaments stabilizing the ankle joint, primarily involved with restricting foot supination. There has been limited research on precise ATFL anatomy and variations, and several studies have conflicting results. The objective of this study was to determine if a correlation exists between ATFL variation and sex, height, weight, and age. In this study, 15 male ankles and 24 female ankles were dissected free of overlying structures to reveal the ATFL, which was classified based on the number of fascicles. Nine of the ligaments had one fascicle, 13 had two incompletely separated fascicles, 12 had two completely separated fascicles, and three had three fascicles. Two ankles had no ATFL. Ligament length and width were measured using the program ImageJ; average length was 19.2 mm and average width was 9.59 mm. Male ligaments were longer and wider than female ligaments. A multivariate regression model was used to assess the influence of sex, height, weight, age, ligament length, and ligament width in predicting ligament variant type; these factors were determined to have no influence. This study found a large amount of ATFL variability, but no correlation between height, weight, age, ligament length, ligament width and ATFL variation. Male ligaments were longer and wider than female ligaments.