Genetic diseases with craniofacial malformations can be associated with anomalies of the craniocervical joint (CCJ). The functions of the CCJ are thus impaired, as mobility may be either limited by abnormal bone fusion causing headaches, or exaggerated in the case of hypermobility, which may cause irreparable damage to the spinal cord. Restoring the balance between mobility and stability requires surgical correction in children. The anatomy and biomechanics of the CCJ are quite unique, yet have been overlooked in the past decades. Pediatric evidence is so scarce, that investigating the adult CCJ is our best shot to disentangle the form-function relationships of this anatomical region. The motivation of the present study was to understand the morphological and functional basis of motion in the CCJ, in the hope to find morphological features accessible from medical imaging able to predict mobility. To do so, we have quantified the in-vitro kinematics of the CCJ in nine cadaveric asymptomatic adults, and estimated a wide range of mobility variables covering the complexity of spinal motion. We compared these variables with the shape of the occipital, the atlas and the axis, obtained using a dense geometric morphometric approach. Morphological joint congruence was also quantified. Our results suggest a strong relationship between bone shape and motion, with the overall geometry predicting best the primary movements, and the joint facets predicting best the secondary movements. We propose a functional hypothesis stating that the musculoligamental system determines movements of great amplitude, while the shape and congruence of joint facets determine the secondary and coupled movements, especially by varying the geometry of bone stops and the way ligaments are tensioned. We believe this work will provide valuable insights in understanding the biomechanics of the CCJ. Furthermore, it should help surgeons treating CCJ anomalies by enabling them to translate objectives of functional and clinical outcome into clear objectives of morphological outcome.

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BACKGROUND: Proximal interphalangeal joint (PIPj) fractures are a common yet challenging injury, particularly in athletes. This case study explores innovative surgical techniques combined with targeted rehabilitation to optimize recovery and functionality.
METHODS: A 20-year-old male soccer goalkeeper sustained a severe Proximal Interphalangeal Joint fracture-dislocation of the third finger during a game. He was treated using the wide awake local anesthesia no tourniquet (WALANT) technique and a Medartis TriLock plate, originally designed for the proximal phalanx but adapted for use on the middle phalanx.
UNASSIGNED: Immediate postoperative mobilization was facilitated by the WALANT technique, enhancing pain management and functional recovery. The adaptation of the TriLock plate, typically not used in this context, proved crucial for stabilizing the complex fracture. Follow-up included regular physiotherapy, focusing on mobility exercises and strength training, which were instrumental in the patient\'s quick return to sport.
CONCLUSIONS: This case underscores the effectiveness of combining innovative surgical adaptations with early rehabilitation in treating complex hand injuries. Such approaches can lead to successful outcomes, significantly improving recovery times and functional results in athletic populations. This strategy may set a precedent for future treatment protocols in sports-related hand injuries.

BACKGROUND: Most studies on cutting have focused on the biomechanics of the knee and lower-limb muscle activation characteristics, with less consideration given to the influence of motor experience on control strategies at the joint level. This study aimed to investigate the differences in knee stability and inter-joint coordination between high- and low-level athletes when cutting at different angles.
METHODS: A Vicon motion capture system and a Kistler force table were used to obtain kinematic and ground reaction force data during cutting. Joint dynamic stiffness and vector coding were used to assess knee stability and inter-joint coordination. Uncontrolled manifold analysis was used to clarify whether there was synergy among lower-limb joints to maintain postural stability during cutting.
RESULTS: During the load acceptance phase, skilled subjects had the smallest joint stiffness at 90° compared with novice subjects (P < 0.05). Compared with novice subjects, skilled subjects had smaller knee-hip ellipse areas at 90° and 135° (P < 0.05), but larger knee-ankle ellipse areas at 135° (P < 0.05). The synergy index in load acceptance was significantly higher (P < 0.05) for skilled subjects at 90° and 135°.
CONCLUSIONS: Advanced subjects can adjust joint control strategies to adapt to the demands of large-angle cutting on the change of direction. Advanced subjects can reduce knee stability for greater flexibility during cutting compared with novice subjects. By increasing the degree of synergy among the lower-limb joints, advanced athletes can maintain high postural stability.

The triangular fibrocartilaginous complex is made of multiple components, of which the palmar and dorsal radioulnar ligaments play an important role in distal radioulnar joint stability. The ulnar wrist ligaments may be injured during forearm and wrist trauma. There are several aspects of triangular fibrocartilaginous complex management that are still open to debate. The aim of the present study was to review the current concepts and discuss emerging trends to better elucidate and treat this important ligament complex.Level of evidence: V.

The suction seal of the hip plays an important role in maintaining hip stability; however, the function of the ligamentum teres in maintaining this seal remains poorly understood. This study aimed to evaluate the effectiveness of the hip suction seal in ligamentum teres deficient hips for joint positions occurring during gait.
Six fresh-frozen human cadaveric hips were dissected and mounted to an Instron materials test system. Each specimen was analyzed for average peak distraction force, stiffness, and total energy during hip displacement. Testing was performed in the native intact ligamentum teres state and the deficient ligamentum teres state. Specimens were examined in 20° of flexion, neutral, and 10° of extension.
In the neutral position, the ligamentum teres deficient state displayed a significant decrease in peak distraction force (mean difference: 33.2 N, p < 0.001), average stiffness (mean difference: 63.7 N/mm, p = 0.016), and total energy (mean difference: 82.3 mJ, p = 0.022) compared to the intact controls. In extension, the deficient state exhibited a significant decrease in peak distraction force (mean difference: 42.8 N, p < 0.001) and total energy (mean difference: 72.9 mJ, p = 0.007). In flexion, the deficient state displayed a significant decrease in peak distraction force relative to contols (mean difference: 7.1 N, p = 0.003).
The ligamentum teres plays a significant role in maintaining the suction seal of the hip, with its effect being most prominent when the hip is in neural alignment or in extension. The findings suggest that ligamentum teres deficiency may be a relevant treatment target in the clinical setting.

Shoulder complex stability can be estimated in vivo through the analysis of helical axes (HAs) dispersion during upper limb movements. The study aimed at investigating test-retest reliability of shoulder HAs dispersion parameters during upper limb tasks. Twenty healthy volunteers performed 2 intransitive (shoulder flexion and rotation) and one transitive (combing) tasks with the dominant and nondominant upper limbs during 2 recording sessions at 1-week distance. Kinematics was detected through an optoelectronic system. Mean distance and mean angle (MA) were adopted as HAs dispersion indexes. Reliability was excellent for mean distance (intraclass correlation coefficient [ICC]: .91) and MA (ICC: .92) during dominant flexion, and good for MA (ICC: .90) during nondominant flexion. Moderate reliability was found for HAs parameters during rotation (ICCs from .70 to .59), except for MA during dominant rotation where reliability was poor. Reliability was good for mean distance (ICC: .83) and moderate for MA (ICC: .67) during the dominant combing task, whereas no reliability was found during the nondominant combing task. HAs dispersion parameters revealed high reliability during simple intransitive tasks with the dominant limb. Reliability decreased with the increase in task complexity due to the increase in movement variability. HAs dispersion technique could be used to assess shoulder complex stability in patients after rehabilitation or surgery.

UNASSIGNED: To investigate the correlation between glenohumeral joint congruence and stability in recurrent shoulder dislocations.
UNASSIGNED: Eighty-nine patients (89 sides) with recurrent shoulder dislocation admitted between June 2022 and June 2023 and met the selection criteria were included as study subjects. There were 36 males and 53 females with an average age of 44 years (range, 20-79 years). There were 40 cases of left shoulder and 49 cases of right shoulder. The shoulder joints dislocated 2-6 times, with an average of 3 times. The three-dimensional models of the humeral head and scapular glenoid were reconstructed using Mimics 20.0 software based on CT scanning images. The glenoid track (GT), inclusion index, chimerism index, fit index, and Hill-Sachs interval (HSI) were measured, and the degree of on/off track was judged (K value, the difference between HSI and GT). Multiple linear regression was used to analyze the correlation between the degree of on/off track (K value) and inclusion index, chimerism index, and fit index.
UNASSIGNED: Multiple linear regression analysis showed that the K value had no correlation with the inclusion index ( P>0.05), and was positively correlated with the chimerism index and the fit index ( P<0.05). Regression equation was K=-24.898+35.982×inclusion index+8.280×fit index, R 2=0.084.
UNASSIGNED: Humeral head and scapular glenoid bony area and curvature are associated with shoulder joint stability in recurrent shoulder dislocations. Increased humeral head bony area, decreased scapular glenoid bony area, increased humeral head curvature, and decreased scapular glenoid curvature are risk factors for glenohumeral joint stability.
UNASSIGNED: 探讨肩关节复发性脱位患者盂肱关节一致性与稳定性的相关性。.
UNASSIGNED: 以2022年6月—2023年6月收治且符合选择标准的89例（89侧）肩关节复发性脱位患者作为研究对象。其中，男36例，女53例；年龄20～79岁，平均44岁。左肩40例，右肩49例。脱位2～6次，平均3次。采用Mimics 20.0软件基于CT扫描图像重建肱骨头及肩胛盂三维模型，测算肩胛盂轨迹（glenoid track，GT）、包容指数、嵌合指数、契合指数、Hill-Sachs间隙（Hill-Sachs interval，HSI），并判断on/off track程度（K值，即HSI与GT差值）。采用多重线性回归分析on/off track程度（K值）与包容指数、嵌合指数、契合指数之间的相关关系。.
UNASSIGNED: 多重线性回归分析示，K值与包容指数无相关（ P>0.05），与嵌合指数、契合指数成正相关（ P<0.05）。回归方程：K=–24.898+35.982×嵌合指数+8.280×契合指数， R 2=0.084。.
UNASSIGNED: 肩关节复发性脱位中，肱骨头、肩胛盂骨性面积及曲率与肩关节稳定性相关。肱骨头骨性面积增大、肩胛盂骨性面积减小、肱骨头曲率增大、肩胛盂曲率减小是影响盂肱关节稳定性的危险因素。.

BACKGROUND: Cranial cruciate ligament (CCL) disease is one of the most common causes of lameness in dogs. The extracapsular stabilization (ECS) utilizing bone anchors and monofilament nylon leader was an alternative treatment for CCL-deficient (CCLD) dogs. However, the biomechanical response of the canine stifle to such a surgical repair strategy in conjunction with the use of recently reported quasi-isometric anchoring points remains unclear. The objectives of the study were to evaluate the mobility and stability of CCL-intact, CCLD, and CCLD stifles repaired with ECS at two different pairs of quasi-isometric points (quasi-IPs).
METHODS: Twelve stifle specimens from 7 dogs underwent mobility and stability tests under 4 different conditions, namely, CCL-intact, CCLD, and ECS-repaired at 2 different pairs of quasi-IPs (referred to as ECS-IP1 and ECS-IP2). The mobility tests evaluated 6 degrees-of-freedom stifle kinematics during flexion and extension. The stability tests involved cranial drawer and tibial internal rotation (IR) tests at various stifle opening angles and quantifying the cranial tibial translation (CTT) and tibial IR angles under constantly applied loadings.
RESULTS: The ECS repaired at quasi-IPs was shown to restore cranial instability of the stifles with averaged CTT magnitudes < 1.4 mm. During the tibial IR test, the ECS treatments resulted in significantly less tibial IR compared to those in intact CCL stifles. The mobility tests showed similar results.
CONCLUSIONS: The 2 chosen pairs of quasi-IPs were shown to effectively correct the excessive CTT caused by CCLD stifles, whereas the excessive tibial external rotation in comparison to those of intact stifles should be considered for its subsequent influence on joint alignment and the contact pressure applied to the stifle joint.

Although higher anterior knee laxity is an established risk factor of ACL injury, underlying mechanisms are uncertain. While decreased proprioception and altered movement patterns in individuals with anterior knee laxity have been identified, the potential impact of higher laxity on brain activity is not well understood. Thus, the purpose of this study is to identify the impact of different magnitudes of knee laxity on brain function during anterior knee joint loading. Twenty-seven healthy and active female college students without any previous severe lower leg injuries volunteered for this study. Anterior knee laxity was measured using a knee arthrometer KT-2000 to assign participants to a higher laxity (N=15) or relatively lower laxity group (N=12). Functional magnetic resonance images were obtained during passive anterior knee joint loading in a task-based design using a 3T MRI scanner. Higher knee laxity individuals demonstrated diminished cortical activation in the left superior parietal lobe during passive anterior knee joint loading. Less brain activation in the regions associated with awareness of bodily movements in females with higher knee laxity may indicate a possible connection between brain activity and knee laxity. The results of this study may help researchers and clinicians develop effective rehabilitation programs for individuals with increased knee laxity. This article is protected by copyright. All rights reserved.