Background: Accurate hindfoot alignment (HA) assessment is essential for surgical planning of foot and ankle procedures, as measurement errors may lead to inappropriate indication. Weight-bearing computed tomography (WBCT) enables HA assessment through coronal images, typically aligned perpendicular to the second ray. However, this forefoot-based reference may not be appropriate in all clinical scenarios, particularly when isolated hindfoot evaluation is required. This exploratory study sought to evaluate how 3 anatomical reference axes affect HA measurements in patients with different foot deformities. Methods: This retrospective cohort study examined 136 WBCT and standard foot radiographs of patients older than 18 years. HA was measured as hindfoot alignment angle (HAA) in coronal images perpendicular to (1) second ray, (2) ankle mortise (bisection of medial and lateral malleoli), and (3) forefoot midpoint (bisection of first and fifth metatarsal heads). Meary, Sgarlato, hallux valgus, and intermetatarsal I-II and I-V angles assessed foot morphology. Spearman correlation analysis was performed to assess relationships between 2-dimensional (2D) parameters and HAA measurements. Results: Median age was 50.3 years and 64% were female. HAA showed significant variations across different reference systems (second ray: 10.0 degrees, ankle mortise: 15.2 degrees, forefoot midpoint: 12.7 degrees; P < .01), with 20.6% of feet showing a discrepancy exceeding 10 degrees between the second ray and ankle mortise. Spearman correlation analysis showed correlation between HAA and Meary angle across all reference axes (ρ = −0.58 to −0.49, P < .01), and between HAA and Sgarlato angle with second ray referencing (ρ = −0.41, P < .01). Conclusions: Reference axis selection substantially influences 2D HA measurements on WBCT. The ankle mortise reference could provide isolated measurement of HA regardless of concurrent forefoot deformities. When using 2D measurement methods, reference system selection could be tailored to whether surgical planning requires comprehensive foot alignment assessment or isolated hindfoot evaluation. Level of Evidence: Level III, retrospective cohort study.

BACKGROUND:Lateral lengthening calcaneal osteotomy (LLOT, Evans and Hintermann) is widely used to treat progressive collapsing foot deformity (PCFD). In the Evans osteotomy, the cut is performed proximal to the calcaneocuboid joint, carrying a risk of violating the anterior or middle subtalar facet. Hintermann proposed a modified technique placing the osteotomy between the middle and posterior facets to reduce risks. Although anatomical studies have shown potential facet involvement, clinical data on the actual incidence and its impact on long-term outcomes remain scarce. This study aimed to determine the incidence of subtalar facet penetration after LLOT and to evaluate its effect on clinical and radiographic results. METHODS:All patients aged ≥18 years who underwent LLOT (Evans or Hintermann osteotomy) at our institution between January 1, 2010, and December 31, 2020, were included. Postoperative computed tomography (CT) was performed 6 weeks after surgery to assess possible subtalar facet violation. At a minimum follow-up of 5 years, magnetic resonance imaging (MRI) was obtained to evaluate cartilage and ligament integrity. Clinical outcomes at the time of MRI were assessed using the Foot Function Index (FFI) and the American Orthopaedic Foot & Ankle Society (AOFAS) score. Demographic variables, including type of osteotomy and outcome measures, were compared between patients with and without facet penetration. RESULTS:Thirty-one patients met inclusion criteria. Subtalar facet penetration was detected in 11 patients (35%) on postoperative CT. No significant differences were observed between groups with respect to demographic variables. MRI analysis revealed no relevant differences in cartilage degeneration. FFI and AOFAS scores were comparable between groups. CONCLUSION:Subtalar facet penetration occurred in one-third of patients after LLOT (Evans and Hintermann). With the numbers available, no significant differences in clinical or radiographic outcomes were detected at a minimum 5-year follow-up, suggesting that minor facet violations may have limited clinical relevance. LEVEL OF EVIDENCE:Level III, retrospective cohort study.

BACKGROUND:Current literature lacks consensus on managing latent unstable isolated syndesmotic injuries. Stability is considered a prerequisite for a good clinical outcome. But so far, it is unknown how stable isolated syndesmotic lesions heal after conservative and surgical treatment. PURPOSE:The purpose of this study was to retrospectively analyze patients with isolated Grade II syndesmotic lesions according to syndesmotic stability, structural changes and clinical outcome. And whether there is a difference between conservative and surgical treatment. STUDY DESIGN:Retrospective case-control study METHODS: A retrospective analysis of 20 patients (10 conservatively treated, 10 surgically treated) with isolated syndesmotic lesions was conducted, with a minimum 2-year follow-up. Evaluation included bilateral external torque CT for syndesmotic stability, MRI for ligament healing structural changes, and clinical examination with foot-specific patient-reported outcome measures (PROMs). RESULTS:Scarred syndesmosis demonstrated stability in external rotation, with non-significant changes compared to the healthy contralateral side: anterior distance (AD): 0.4 mm ±1.2 (p value 0.718), posterior distance (PD): -0.1 mm ±1.3 (p value 0.709), tibiofibular clear space (TCS): 0.3 mm ±0.8 (p value 0.321), external rotation (ER): 1.8 ° ±2.9 (p value 0.684). No statistically significant differences were observed between conservative and operative treatments regarding syndesmotic stability, structural changes, or clinical outcomes. CONCLUSION:Conservative and operative treatments for isolated Grade II syndesmotic lesions achieved comparable results in syndesmotic stability and healing.

Background: Understanding syndesmotic injury in conjunction with lateral ligament disruption is essential for accurate diagnosis and treatment. Although the influence of deltoid ligament injury on syndesmotic evaluation during bilateral external torque computed tomography (BET-CT) has been examined, the effect of concurrent lateral ligament lesion remains unclear and is rarely examined in the literature. This leads to the question of whether a lateral ligament lesion influences the previously established measurement parameters of syndesmosis instability in BET-CT and whether it results in a quantifiable increase in tibiotalar instability. Methods: Seven paired cadaveric lower limbs (n = 14; mean age 78.6 years) with pre-existing iatrogenic syndesmotic transection underwent sequential lateral ligament sectioning: anterior talofibular (ATFL), calcaneofibular (CFL), and posterior talofibular ligaments (PTFL). BET-CT imaging was performed under applied external rotation torques of 0, 2.5, 5.0, and 7.5 Nm. Outcome measurements included the anterior tibiofibular distance, tibiofibular clear space, posterior tibiofibular distance, medial tibiotalar gutter angle, and lateral fibulotalar gutter angle for each ligament condition and torque level. Results: The anterior tibiofibular distance remained stable despite progressive lateral ligament dissection and increasing torque ( P > .05). Tibiofibular clear space and posterior distance measurements showed inconsistent trends and did not reach statistical significance. In contrast, the medial tibiotalar gutter angle increased significantly from 22.9° in isolated syndesmotic injury to 27.6° (±6.3°) following complete disruption of the lateral complex ( P < .001). Conclusion: Concurrent lateral ligament injury does not impair the assessment of syndesmotic widening in BET-CT, as tibiofibular alignment remains preserved. However, disruption of the lateral complex exacerbates rotational tibiotalar instability. Clinical Relevance: In this cadaveric model, BET-CT remains reliable for assessing syndesmotic lesions even in the presence of lateral ligament injury. However, the increase in rotational tibiotalar instability with combined injuries highlights the need for comprehensive evaluation of ankle ligament injuries, pending clinical validation.

Background:The Hintermann osteotomy (HOT) is one type of calcaneal lengthening osteotomy during progressive collapsing foot deformity surgery. The entry point on the lateral wall of the calcaneus is critical because it affects the direction and depth of the osteotomy. Accurate osteotomy placement can be technically demanding, and joint facets can sustain damage in up to 50% of the cases. We hypothesize that the further posterior the osteotomy is performed, the greater the risk of facet injury. Methods:Twenty-two computed tomography-based 3-D models underwent simulated HOT at 5, 10, 15, 20 mm posterior to the calcaneocuboid joint. Primary outcomes were facet penetration rate and "safe-zone" angle; secondary outcomes were distance to the flexor hallucis longus (FHL) and anterior-facet translation. Results:Facet penetration increased from 0% (0/22) with entry points 5 to 15 mm posterior to the calcaneocuboid joint to 23% (5/22) at 20 mm. The safe-zone angle narrowed from 11 ± 2.6 degrees at 5 mm to 3.0 ± 6.5 degrees at 20 mm (P < .01). Mean FHL clearance decreased from 44 ± 6 mm to 35 ± 6 mm (-20%, P < .05), and anterior-facet translation increased by 32% between the 5- and 20-mm cuts. Conclusion:The choice of the entry point is crucial. If an entry point is chosen 20 mm behind the calcaneocuboid joint, facet penetration is anatomically inevitable in 23% of cases. A more anterior entry point results in a longer distance between the lateral wall and the sensitive medial structures. Level of Evidence:Level IV, case series.

BACKGROUND:Ultrasound-based bone surface segmentation is crucial in computer-assisted orthopedic surgery. However, ultrasound images have limitations, including a low signal-to-noise ratio, acoustic shadowing, and speckle noise, which make interpretation difficult. Existing deep learning models for bone segmentation rely primarily on costly manual labeling by experts, limiting dataset size and model generalizability. Additionally, the complexity of ultrasound physics and acoustic shadow makes the images difficult for humans to interpret, leading to incomplete labels in low-intensity and anechoic regions and limiting model performance. To advance the state-of-the-art in ultrasound bone segmentation and establish effective model benchmarks, larger and higher-quality datasets are needed. METHODS:We propose a methodology for collecting ex-vivo ultrasound datasets with automatically generated bone labels, including anechoic regions. The proposed labels are derived by accurately superimposing tracked bone Computed Tomography (CT) models onto the tracked ultrasound images. These initial labels are refined to account for ultrasound physics. To clinically evaluate the proposed method, an expert physician from our university hospital specialized in orthopedic sonography assessed the quality of the generated bone labels. A neural network for bone segmentation is trained on the collected dataset and its predictions are compared to expert manual labels, evaluating accuracy, completeness, and F1-score. RESULTS:We collected UltraBones100k, the largest known dataset comprising 100k ex-vivo ultrasound images of human lower limbs with bone annotations, specifically targeting the fibula, tibia, and foot bones. A Wilcoxon signed-rank test with Bonferroni correction confirmed that the bone alignment after our optimization pipeline significantly improved the quality of bone labeling (p<0.001). The model trained on UltraBones100k consistently outperforms manual labeling in all metrics, particularly in low-intensity regions (at a distance threshold of 0.5 mm: 320% improvement in completeness, 27.4% improvement in accuracy, and 197% improvement in F1 score) CONCLUSION:: This work is promising to facilitate research and clinical translation of ultrasound imaging in computer-assisted interventions, particularly for applications such as 2D bone segmentation, 3D bone surface reconstruction, and multi-modality bone registration.

Background: Subtle chronic or latent instabilities are difficult to delineate with currently available diagnostic modalities and do not allow assessment of ligamentous functionality. The noninvasive bilateral external torque computed tomography (CT) was able to reliably detect syndesmotic lesions in a cadaveric study. The aim of the study was to test the external torque device in young, healthy subjects at 3 different torque levels and to demonstrate comparability with the contralateral side. Methods: Ten healthy subjects without history of injury or surgery to the ankle joint were enrolled in this cross-sectional study. Four CT scans were performed. During the scans, the lower legs and feet were placed in an external torque device with predefined external rotation torques of 0, 2.5, 5, and 7.5 Nm. Five different radiographic measures of syndesmotic stability were measured: anterior distance (AD), tibiofibular clear space (TCS), posterior distance (PD), external rotation (ER), and β angle. Results: With increasing external torque, slight increases in AD, ER, and β angle were observed, whereas TCS and PD decreased slightly. Large absolute differences were found between the healthy subjects for all measured parameters, regardless of the external torque applied. Differences from the contralateral side using the same external torque were minimal for all parameters, but smallest for AD with a maximum difference of 0.5 mm. Conclusion: Using the healthy contralateral ankle joint is appropriate for assessing syndesmotic stability based on minimal intraindividual side differences using the external torque device. Side differences >0.5 mm in AD and >0.9 mm in PD may be considered abnormal and may indicate significant instability of the syndesmosis. However, future studies are needed to define definitive cutoff values for relevant side differences in acute and chronic syndesmotic instability to guide clinicians in their treatment decisions.

Despite growing numbers of scientific publications on the optimal antibiotic treatment for diabetic foot infections, the data on the adult population with non-diabetic (postsurgical) foot infections is limited. Therefore, one of the largest single-center databases at the Balgrist University Hospital in Zurich, Switzerland, was established between January 2014 and August 2022. Using a case–control study design, we retrospectively investigated failures of combined surgical and antibiotic therapy for surgical site foot infections (SSIs). Overall, 17.4% of the episodes experienced therapeutic failures, particularly in patients with infected ankle prostheses. However, age, biological sex, pathogens, the duration of post-debridement antibiotic treatment, the number of surgical debridements, or the use of negative-pressure wound care altered the failure risk. In the multivariate logistic regression analyses, the duration of postsurgical antibiotic use was completely indifferent (as a continuous variable with an odds ratio of 1.0 and a 95% confidence interval ranging from 0.96 to 1.03) when stratified into inter-tertiary groups. Our findings suggest that shorter courses of systemic antibiotics may be appropriate in non-diabetic adults, supporting better antibiotic stewardship. Ongoing randomized controlled trials are under way to investigate which patients might safely receive shorter antibiotic treatments for surgical site infections following elective foot and ankle procedures.

BACKGROUND:If tibiofibular syndesmotic injury is undetected, chronic instability may lead to persistent pain and osteoarthritis. So far, no reliable diagnostic method has been available. The primary objectives of this study were to determine whether defined lesions of the syndesmosis can be correlated with specific tibiofibular joint displacements caused by external rotational torque and to compare the performance of bilateral external torque computed tomography (BET-CT) and arthroscopy. Secondary objectives included an evaluation of the reliability of CT measurements and the suitability of the healthy contralateral ankle as a reference. METHODS:Seven pairs of healthy, cadaveric lower legs were tested and assigned to 2 groups: (1) supination-external rotation (SER) and (2) pronation-external rotation (PER). In the intact state and after each surgical step, an ankle arthroscopy and 3 CT scans were performed. During the scans, the specimens were placed in an external torque device with 2.5, 5.0, and 7.5 Nm of torque applied. RESULTS:The arthroscopic and CT parameters showed significant correlations in all pairwise comparisons. The receiver operating characteristic (ROC) curve analyses yielded the best prediction of syndesmotic instability with the anterior tibiofibular distance on CT, with a sensitivity of 84.1% and a specificity of 95.2% (area under the curve [AUC], 94.8%; 95% confidence interval [CI], 0.916 to 0.979; p < 0.0001) and with the middle tibiofibular distance on arthroscopy, with a sensitivity of 76.2% and specificity of 92.3% (AUC, 91.2%; 95% CI, 0.837 to 0.987; p < 0.0001). Higher torque amounts increased the rate of true-positive results. CONCLUSIONS:BET-CT reliably detects experimental syndesmotic rotational instability, compared with the healthy side, with greater sensitivity and similar specificity compared with the arthroscopic lateral hook test. Translation of these experimental findings to clinical practice remains to be established. LEVEL OF EVIDENCE:Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:In progressive collapsing foot deformity (PCFD), an internal and plantar rotation of the talus relative to the calcaneus may result in painful peritalar subluxation. Medial soft tissue procedures (eg, spring ligament repair) aim to correct the talar position via the navicular bone if bony correction alone is not sufficient. The effect of the medial soft tissue reconstruction on the talar reposition remains unclear. We hypothesized that a subtalar talocalcaneal ligament reconstruction might be favorable in PCFD to correct talar internal malposition directly. This pilot study aims to evaluate the anatomical feasibility and kinematic behavior of a subtalar ligament reconstruction in PCFD. METHODS:Three-dimensional surface model from 10 healthy ankles were produced. A total of 1089 different potential ligament courses were evaluated in a standardized manner. A motion of inversion/eversion and talar internal/external in relation to the calcaneus were simulated and the ligament strain, expressed as a positive length variation, for each ligament was analyzed. The optimal combination for the ligament reconstruction with increased length in internal rotation of the talus, isometric kinematic behavior in inversion/eversion, and extraarticular insertion on talus and calcaneus was selected. RESULTS:A laterodistal orientation of the talar insertion point in respect to the subtalar joint axis and laterodistal deviation of the calcaneal insertion point presents the highest ligament lengthening in internal talar rotation (+0.56 mm [3.8% of total length]) and presented a near-isometric performance in inversion/eversion (+0.01 to -0.01 mm [0.1% of total length]). CONCLUSION:This kinematic model shows that a ligament reconstruction in the subtalar space presents a pattern of length variation that may stabilize the internal talar rotation without impeding the physiological subtalar motion. CLINICAL RELEVANCE:This study investigates the optimal location, feasibility, and kinematic behavior of a ligament reconstruction that could help stabilize peritalar subluxation in progressive collapsing foot deformity. [Formula: see text].

Abstract Purpose Primary glenohumeral osteoarthritis is commonly associated with static posterior subluxation of the humeral head. Scapulae with static/dynamic posterior instability feature a superiorly and horizontally oriented acromion. We investigated whether the acromion acts as a restraint to posterior humeral translation. Methods Five three‐dimensional (3D) printed scapula models were biomechanically tested. A statistical shape mean model (SSMM) of the normal scapula of 40 asymptomatic shoulders was fabricated. Next, a SSMM of scapular anatomy associated with posterior subluxation was generated using data of 20 scapulae (“B1”). This model was then used to generate three models of surgical correction: glenoid version, acromial orientation, and acromial and glenoid orientation. With the joint axially loaded (100N) and the humerus stabilized, an anterior translation force was applied to the scapula in 35°, 60° and 75° of glenohumeral flexion. Translation (mm) was measured. Results In the normal scapula, the humerus translates significantly less to contact with the acromion compared to all other configurations (p < .000 for all comparisons; i.e. 35°: “normal” 8,1 mm (± 0,0) versus “B1” 11,9 mm (± 0,0) versus “B1 Acromion Correction” 12,2 mm (± 0,2) versus “B1 Glenoid Correction” 13,3 mm (± 0,1)). Restoration of normal translation was only achieved with correction of glenoid and acromial anatomy (i.e. 75°: “normal” 11 mm (± 0,8) versus “B1 Acromion Correction” 17,5 mm (± 0,1) versus “B1 Glenoid Correction” 19,7 mm (± 1,3) versus “B1 Glenoid + Acromion Correction” 11,5 mm (± 1,1)). Conclusions Persistence or recurrence of static/dynamic posterior instability after correction of glenoid version alone may be related to incomplete restoration of the intrinsic stability that is conferred by a normal acromial anatomy. Level of Evidence V biomechanical study

Background: Painful degenerative joint disease (DJD) of the first metatarsophalangeal joint (MTP I), or hallux rigidus, mainly occurs in later stages of life. For end-stage hallux rigidus, MTP I arthrodesis is considered the gold standard. As young and active patients are affected considerably less frequently, it currently remains unclear, whether they benefit to the same extent. We hypothesized that MTP I arthrodesis in younger patients would lead to an inferior outcome with decreased rates of overall with lower rates of patient postoperative pain and function compared to an older cohort.Methods: All patients aged <50 y ears who underwent MTP I arthrodesis at our institution between 1995 and 2012 were included in this study. This group was then matched and compared with a group of patients aged >60 years. Minimum follow-up was 10 years. Outcome measures were Tegner activity score (TAS), a "Virtual Tegner activity score" (VTAS), the visual analog scale (VAS), and the Foot Function index (FFI).Results: Sixty-one MTP I fusions (n = 28 young, n = 33 old) in 46 patients were included in our study at an average of 14 years after surgery. Younger patients experienced significantly more pain relief as reflected by changes in VAS and FFI Pain subscale scores. No difference in functional outcomes was found with change in the FFI function subscale or in the ability to have desired functional outcomes using the ratio of TAS to VTAS. Revision rate did not differ between the two groups apart from hardware removal, which was significantly more likely in the younger group.Conclusion: In patients below the age of 50 years with end-stage DJD of the first metatarsal joint, MTP I arthrodesis not only yielded highly satisfactory postoperative results at least equal outcome compared to an older cohort of patients aged >60 years at an average 14 years' follow-up. Based on these findings, we consider first metatarsal joint fusion even for young patients is a valid option to treat end-stage hallux rigidus.Level of Evidence: Level III, a case-control study.

ZusammenfassungDer Begriff Arthrose bezeichnet eine degenerative Gelenkerkrankung, von der jedes Gelenk betroffen sein kann. Unter Omarthrose wird der Gelenkverschleiß des Glenohumeralgelenks verstanden. Der Beitrag bietet Ihnen ein Update zu Operationen und Physiotherapie nach Omarthrose-OP.

Background: Acromial and scapular spine fractures are common complications after reverse total shoulder arthroplasty (RTSA). There is limited information on the treatment outcome of these fractures. Therefore, the purpose of this study was to compare the clinical outcome of operative and conservative treatment of patients with acromial or scapular spine fractures. Methods: A total of 1146 RTSAs were performed in our institution between 1999 and 2016. In 23 patients (2%), we identified an acromial fracture, and in 7 cases (0.6%), a scapular spine fracture in the postoperative course. Of those patients, 7 patients (23%) were treated with open reduction and internal fixation and 23 (77%) were treated conservatively. We compared the outcome of operative vs. conservative treatment assessing the Constant score (CS), range of motion, and subjective shoulder value (SSV). Fractures were classified by the system of Crosby. Radiographic assessment consisted of measuring the healing rate, time to heal, and the displacement of the acromion before and immediately after the fracture as well as after treatment. Results: There were no statistically significant differences between operative and conservative treatment. The mean preoperative CS in the operative group was 32 points and improved to 45 points after surgery, whereas it was 35 points in the conservative group and improved to 61 points at the final follow-up. The mean SSV improved from 20 to 50 points in the operative group and from 22 to 58 points in the conservative group. Mean active flexion changed from 59 to 75, mean abduction from 68 to 67, and external rotation from 25 & DEG; to 13 in the operative group and from 75 to 91, 67 to 92, and 28 to 24 in the conservative group. Conclusions: In our study, operative treatment was not superior to conservative treatment, neither for CS, SSV, or range of motion. Both treatment forms, however, resulted in inferior results to those previously reported for RTSA without postoperative acromion fractures. Before better surgical methods have been developed, conservative treatment of acromial fractures may be the better treatment option for acromial fractures after RTSA. (c) 2022 Published by Elsevier Inc. on behalf of Journal of Shoulder and Elbow Surgery Board of Trustees.

Progressive collapsing foot deformity (PCFD) is a complex 3-dimensional (3-D) deformity with varying degrees of hindfoot valgus, forefoot abduction, and midfoot varus. The first aim of this study was to perform a 3-D analysis of the talus morphology between symptomatic PCFD patients that underwent operative flatfoot correction and controls. The second aim was to investigate if there is an impact of individual talus morphology on the success of operative flatfoot correction. We reviewed all patients that underwent lateral calcaneal lengthening for correction of PCFD between 2008 and 2018 at our clinic. Radiographic flatfoot parameters on preoperative and postoperative radiographs were assessed. Additionally, 3-D surface models of the tali were generated using computed tomography (CT) data. The talus morphology of 44 flatfeet was compared to 3-D models of 50 controls without foot or ankle pain of any kind. Groups were comparable regarding demographics. Talus morphology differed significantly between PCFD and controls in multiple aspects. There was a 2.6° increased plantar flexion (22.3° versus 26°; p = 0.02) and medial deviation (31.7° and 33.5°; p = 0.04) of the talar head in relation to the body in PCFD patients compared to controls. Moreover, PCFD were characterized by an increased valgus (difference of 4.6°; p = 0.01) alignment of the subtalar joint. Satisfactory correction was achieved in all cases, with an improvement of the talometatarsal-angle and the talonavicular uncoverage angle of 5.6° ± 9.7 (p = 0.02) and 9.9° ± 16.3 (p = 0.001), respectively. No statistically significant correlation was found between talus morphology and the correction achieved or loss of correction one year postoperatively. The different morphological features mentioned above might be contributing or risk factors for progression to PCFD. However, despite the variety of talar morphology, which is different compared to controls, the surgical outcome of calcaneal lengthening osteotomy was not affected. III.