Three-dimensional in vivo kinematics of the subtalar joint during weight-bearing standing on coronal-wedge surfaces using upright computed tomography.

Nailing versus plating in tibiotalocalcaneal arthrodesis - A biomechanical human cadaveric study.

Background/Objectives: Triple arthrodesis (TA) involves fusion of subtalar, talonavicular and calcaneocuboid joints. In the paediatric population, this procedure is used to correct foot deformities, augment stability and decrease pain, often in neuromuscular conditions. There is limited research into long-term outcomes of paediatric TA in regards to patient quality of life (QOL). This study aims to retrospectively evaluate the long-term patient-reported outcomes of the paediatric TA at a single centre. Methods: All paediatric patients who underwent TA at the Women’s and Children’s Hospital between 1998 and 2012 were identified from operative records and the patient and/or their carer were given the opportunity to be interviewed. Patient-reported outcomes were measured over the phone using the Foot and Ankle Ability Measure (FAAM) and Manchester-Oxford Foot and Ankle Questionnaire (MOXFQ) tools. Results: Eighteen patients were included in the study, with a total of 23 feet, with five patients having bilateral surgery in the one sitting. Follow-up was at a mean time of 17 years post-surgery, with a mode of 20 years. There were recurring themes of continued pain plus impaired function and mobility, especially in children who could not walk prior to surgery. Derived from the FAAM, the average Activities of Daily Living Scale was 39.81%, with four patients at 0%. The MOXFQ outcomes for walking, pain and social interaction domains were converted from the Likert scale into an average total score of 34.99/64. Over half of the patients continued to have pain after the surgery in adult life. Conclusions: This study highlights variable results post-paediatric triple arthrodesis, with concerning rates of limited improvement in functional outcomes, ongoing pain and negative psychosocial impact in adulthood, as reported by the patient or their carer.

Pilon fractures result in substantial morbidity and are associated with a high rate of ankle arthritis. However, literature is scarce regarding the prevalence of posttraumatic subtalar arthritis. Tibiotalocalcaneal (TTC) arthrodesis, or hindfoot nailing, is increasingly used for comminuted pilon fractures, which often involve the subtalar joint. This study aimed to determine the prevalence and severity of posttraumatic subtalar arthritis, to better understand the implications of this surgical technique in these cases. Patients who sustained a pilon fracture and underwent open reduction and internal fixation were retrospectively identified. The patients were categorized into 4 groups on the basis of the time interval between the date of injury and the latest available radiographs: <12, 12 to 24, 25 to 48, and >forty-eight months. The Kellgren-Lawrence (K-L) and NSS (None, Some, Severe) grading systems were used to evaluate the radiographs. Postoperative computed tomography (CT) scans, when available, were similarly graded using the CT Ankle Osteoarthritis (CTAO) system. Pearson correlation, chi-square, Mann-Whitney U, and Welch t tests were used. P < 0.05 was considered significant. The study included 473 patients (mean age, 46.15 ± 7.50 years, 293 male and 180 female). The cohort was composed of 80.3% White and 15.8% non-White, with 3.9% missing data.(Patient age at the time of injury (p < 0.001) and at the time of imaging (p < 0.001), smoking status (p = 0.01), steroid use (p = 0.04), Charlson Comorbidity Index (CCI) (p = 0.003), AO/OTA classification (p = 0.03), and time from injury to final imaging (p = 0.004) were significantly correlated with the K-L grade. Group 3 was found to have a higher mean K-L grade than Group 1 (by 0.34, 95% confidence interval [CI]: 0.03 to 0.66; p = 0.04) and Group 2 (by 0.39, 95% CI: 0.05 to 0.73; p = 0.02). Group 4 had a higher K-L grade than Group 1 (by 0.37, 95% CI: 0.08 to 0.66; p = 0.01) and Group 2 (by 0.42, 95% CI: 0.11 to 0.73; p = 0.01). The CTAO score demonstrated meaningful correlation between subtalar arthritis and age at both the time of injury (p = 0.004) and the time of final CT (p = 0.01). Multiple patient-based factors including age, smoking status, steroid use, CCI, AO/OTA classification, and the time interval since injury were significantly associated with the development of subtalar arthritis, as assessed using the K-L grade, after pilon fracture. This suggests that acute hindfoot nailing as an index treatment option for pilon fractures may have fewer clinical ramifications than has been anticipated on the basis of its violation of the subtalar joint. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The purpose of this study was to assess the subtalar joint's kinematics in in the frontal plane (inversion-eversion) using 3D weightbearing cone beam computed tomography by measuring both translational and angular range of motion. In this cohort study, weightbearing cone beam computed tomography images were acquired of 41 subjects under weightbearing stress in 20 degrees inversion and 10 degrees eversion tilt, achieved with hard plastic wedges. The ankle was in neutral position, and the sole of the foot was entirely on the wedge. Interobserver and intraobserver reliability were assessed using intraclass correlation coefficients. All the measured numeric range of motion values in the normal subtalar joint's bony structures were small; however, values were larger in eversion than in inversion. Translational range of motion in the middle facet (1.4 mm) is smaller than in the anterior facet (4.9 mm). Reliability was good to excellent for most parameters; however, several showed poor reliability-particularly interobserver agreement for inversion measures of the middle-facet angle/translation and select talocrural metrics (midpoint/medial joint-space width, joint angle). This study defines the subtalar joint's translational and angular range of motion in the frontal plane (inversion-eversion) under weightbearing stress in normal subtalar joint's bony structures. The applicability of the method should be investigated in different patient groups.

Intrinsic subtalar ligaments are primary varus stabilizers of the subtalar joint: A 3D cadaveric motion analysis.

Evaluation of the location of the weight-bearing line on the ankle in varus ankle osteoarthritis using weight-bearing long-leg anteroposterior view: A retrospective clinical study.

Biomechanical effects of varying arch support hardness in foot orthosis for adults with flexible flatfoot: A comprehensive Bayesian statistical analysis.

Lateral Subtalar Joint Capsuloligamentous Instability: A Review and Proposed Repair Technique

Subtalar arthrodesis presents a challenge to the surgeon due to the complexity of joint anatomy and a limited blood supply, which can slow healing. In revision procedures these challenges are even more prevalent. A 72-year-old male patient presented with a failed subtalar arthrodesis performed two years prior with constant pain (VAS 7/10) and antalgic gait, with tenderness at the subtalar joint. The revision surgery included the replacement of the original screws with larger fully threaded screws. A silicate enriched (5.8wt% silicon) calcium phosphate bone graft substitute (OssDsign Catalyst®) was developed recently with nanoarchitecture and site-specific silicate substitution to mimic the structure of natural bone and follow the healing pathways more commonly associated with autograft or biologics, including both intramembranous and endochondral ossification. Five ccs of Catalyst bone graft substitute were mixed with a small amount of calcaneal autograft thus completing the revised construct. X-Ray and CT Scans at 3-month follow-up showed intact and well positioned screws and evidence of early and complete consolidation of the bone graft. The patient returned to full weight bearing and was free of pain, walking with regular shoes. There were no intraoperative or post-operative complications. The choice of larger fully threaded screws and selection of a synthetic bone graft highly suited for challenging environments with limited blood supply (endochondral ossification), allowed the surgeon to achieve unexpected early arthrodesis and excellent clinical outcome.

This study constructed a statistical shape model (SSM) of the full ankle joint-including the tibia, talus, calcaneus, and fibula-in healthy Chinese males and analyzed the variation patterns of joint space width (JSW). Computed tomography scans of 108 asymptomatic ankle joints were collected from healthy Chinese males and used to construct a statistical shape model based on principal component analysis. Anatomical variations were evaluated using spatial mapping and least-squares regression. The statistical shape model satisfied the validation criteria for accuracy, compactness, generalization, and specificity, and participants demonstrated high conformity in joint surface coverage and congruency. The first principal component explained more than 22% of the total variance. The minimum joint space widths for the tibiotalar, talofibular, and talocalcaneal joints ranged from 0.85 to 1.95mm, 0.87 to 2.39mm, and 0.90 to 3.32mm, respectively, while the average joint space widths ranged from 2.81 to 3.35mm, 1.36 to 3.36mm, and 2.12 to 4.95mm, respectively. Regression analysis showed that the first five principal modes of variation were strongly correlated with anatomical variations in ankle JSW. This study will provide theoretical support for the early diagnosis and personalized treatment of ankle joint diseases, as well as important morphological references for prosthesis design and biomechanical simulation research.

BackgroundFlexible flatfoot is a common foot deformity in adolescents. Subtalar arthroereisis can help reduce excessive foot pronation by placing an implant in the subtalar joint. In recent years, this method has been widely used to treat adolescent flexible flat feet. However, some postoperative complications may occur 3–6 months after subtalar arthroereisis, and few studies have explored plantar pressure and lower limb muscle activation patterns during this period.MethodsTwenty adolescents with flexible flatfoot deformities who underwent subtalar arthroereisis were enrolled in this study. The plantar areas of all patients were divided into eight regions, and the average standing pressure and peak pressure during the gait cycle were compared before and three months after surgery. Surface electromyography (sEMG) of the tibialis anterior (TA), peroneus longus (PL), and medial gastrocnemius (MG) muscles was simultaneously measured during a single gait cycle.ResultsAll patients were able to walk in their shoes at 3 months postoperatively. After surgery, while standing, the average pressure on the lesser toes, lateral forefoot, and lateral midfoot increased significantly (p < 0.05). In contrast, the pressure of the hallux region, medial forefoot, medial midfoot, medial hindfoot, and lateral hindfoot decreased significantly (p < 0.05). During the gait cycle, the peak pressure in the lesser toes, lateral forefoot, lateral midfoot, and lateral hindfoot increased significantly (p < 0.05), whereas that in the hallux, medial forefoot, medial midfoot, and medial hindfoot decreased significantly (p < 0.05). The maximum lateral displacement of the center of pressure (COP) decreased from 3.81 ± 0.56 cm preoperatively to 3.59 ± 0.41 cm postoperatively. The maximum longitudinal displacement decreased from 21.07 ± 3.96 cm to 19.37 ± 3.08 cm (p < 0.05), and the COP trajectory curve shifted laterally. During the gait cycle, the peak activation percentage of TA significantly decreased postoperatively, that of the PL significantly increased after surgery, and that of the MG significantly decreased. The integral percentage of TA activation was significantly reduced postoperatively. The integral percentage of PL activation was significantly higher than that at the preoperative stage. Additionally, the integral percentage of MG activation was significantly lower than that of the preoperative value. (all p < 0.05).ConclusionThis study found that plantar pressure shifted laterally during the early postoperative period. Such changes in plantar pressure distribution may compensate for alterations in lower limb muscle activation patterns, which may potentially contribute to postoperative plantar pain or painful peroneal muscle spasm. Therefore, monitoring plantar pressure distribution and muscle activation in the early postoperative period is recommended.

Three-Dimensional Navigation for Talocalcaneal Coalition Resection: A Comparative Analysis.

Synovial chondromatosis (SC) is a rare, benign neoplastic process involving multiple hyaline cartilaginous nodules in the subsynovial tissue of a joint, tendon sheath or bursa. Primary intraarticular SC (PISC) is an idiopathic and largely monoarticular, involving large joints. Most cases occur at the knee, then the hip, elbow, shoulder and ankle. PISC is rare in the foot. We present the case of a 38-year-old male with a three-year history of indolent and progressive unilateral right foot swelling and pain with PISC of the right calcaneocuboid joint (CCJ) and review the literature. A literature review revealed one case of PISC of the CCJ that did not describe radiological features and one case of PISC of the subtalar joint that extended into CCJ.

BackgroundThe deep, flexor hallucis longus (FHL)-associated part of Kager’s fat pad (KFP-F) is adjacent to structures implicated in the pathophysiology of posterior ankle impingement syndrome (PAIS), and pathological changes within Kager’s fat pad itself are also observed in PAIS. However, the detailed topographical relationships of these structures in the deep ankle remain insufficiently understood. This study aimed to provide a comprehensive anatomical description of the KFP-F and its relationship with surrounding neurovascular and musculoskeletal structures.MethodsFifty legs from 28 Japanese cadavers (28 male, 22 female; mean age at death, 78 years) were examined. The presence or absence of direct contact and positional relationship between the KFP-F with FHL, tibial nerve, posterior tibial artery, posterior tibial vein, talocrural joint capsule, and subtalar joint capsule was systematically evaluated. The width of the contact interface of KFP-F with the talocrural and subtalar capsules were measured and compared.ResultsThe KFP-F demonstrated direct contact with the FHL and the talocrural and subtalar joint capsules in all specimens. In 45 ankles (90%), the KFP-F also demonstrated direct contact with the tibial nerve, posterior tibial artery, and posterior tibial vein. Notably, the KFP-F was observed to circumferentially envelop the superficial and deep aspects of the FHL and neurovascular structures. The width of the contact interface with the talocrural joint capsule was significantly greater than that with the subtalar joint capsule (p < 0.01).ConclusionThe KFP-F forms circumferentially enveloping relationship with the FHL and the posterior tibial neurovascular bundle. This detailed topographical description provides a crucial foundation for improving the interpretation of diagnostic imaging and refining surgical approaches for deep posterior ankle pain.

Rates of subtalar joint osteoarthritis after modified Chrisman-snook.

Subtalar Joint Nonunions Following Isolated Ipsilateral Ankle Arthrodesis a Systematic Review and Meta Analysis.

Combined supramalleolar osteotomy and ankle arthrodesis for end-stage ankle arthritis with large varus deformity.

Cardan sequence selection influences subtalar and talonavicular joint kinematics.

It is well documented that limb salvage interventions may induce or exacerbate biomechanical dysfunction in the residual limb. As a result, patients with Charcot's neuroarthropathy (CN) are at theoretical risk for progression of or novel neuroarthropathic breakdown, which has been observed in the midfoot after amputation; however, this has not been investigated in rearfoot interventions such as partial calcanectomy. We retrospectively identified eight patients during a 7.25-year period who had a history of CN and partial calcanectomy in the ipsilateral limb. Patients with contralateral involvement were excluded, and included medical records were analyzed and radiographically characterized. The mean patient age was 73.9 years (range, 59-86 years), and the mean body mass index was 31.4 (range, 22-50). Two patients (25.0%) demonstrated multijoint breakdown. Two feet (25.0%) were characterized as Sanders-Frykberg (SF) II, one (12.5%) as SF III, and three (37.5%) as SF IV/V breakdown. Three patients developed CN a mean of 350.3 days after partial calcanectomy was performed. The mean age and body mass index of patients who experienced post-vertical contour calcanectomy CN was 70.7 years (range, 59-83 years) and 29.0 years (range, 22-35 years), respectively. All instances of postcalcanectomy CN resulted in rearfoot breakdown, with one (33.3%) isolated to the tibiotalar joint and two (66.7%) at the tibiotalar and subtalar joints. A 66.7% limb salvage rate was found in patients who developed postcalcanectomy CN. We conclude that partial calcanectomy in patients with antecedent CN does not result in clinically significant changes that further threaten the limb but identified three instances where partial calcanectomy destabilized the rearfoot and resulted in rearfoot CN breakdown. Although this knowledge should not discourage the use of calcanectomies, clinicians should be cognitive of complications such as CN breakdown that can further threaten the limb.