Severe musculoskeletal disease characterized by marked joint laxity was the cause of euthanasia in two wild juvenile American black bears (Ursus americanus) admitted to a rehabilitation facility in eastern Tennessee in 2023. Previously, almost all reported musculoskeletal diseases in this population were of traumatic etiology, even in malnourished yearlings. Case 1 was an orphaned 11-month-old male cub exhibiting disproportionate dwarfism, progressive immobility, and joint laxity. Necropsy findings suggested either chondrodysplasia or rickets, and imaging findings supported a skeletal dysplasia. Case 2 was a 14-month-old emaciated male yearling exhibiting joint laxity and immobility. Necropsy findings showed osteoporosis and serous atrophy of fat, and imaging findings were inconsistent with a skeletal dysplasia. Both cases were clinically inconsistent with rickets based on normal calcium, phosphorous, and parathyroid hormone concentrations; however, Case 1 had hypovitaminosis D (9 nmol/L) compared to healthy juvenile black bears. We hypothesize that Case 1 had a genetic chondrodysplasia while the osteoporosis of Case 2 was due to chronic malnutrition. The goal of this case report is to inform wildlife agencies and facilities to monitor for similar, non-trauma-related debilitating musculoskeletal disease in free-ranging bears and evaluate cases that allow us to further understand the disease processes involved.

BACKGROUND: Temporomandibular disorders (TMDs) and cervical spine problems are a growing public health issue, as they increase the risk of disability in people with hypermobility joint syndrome (HJS).
OBJECTIVE: The present study aimed to assess the prevalence of TMD symptoms, and cervical spine and TMJ disability in HJS patients.
METHODS: A survey was conducted among physical therapy students (mean age: 21 years). The study comprised 2 stages. The 1st one was HJS assessment (the Beighton scale and the Brighton criteria). Based on the assessment, 56 HJS subjects were enrolled for the study. The control group (CG) consisted of 60 HJS-free subjects, according to the aforementioned criteria. The 2nd stage of the study involved conducting a self-administered questionnaire on the prevalence of TMD symptoms. Both the TMD disability questionnaire (TMD-Q) and the neck disability index (NDI) scores were recorded. Pain intensity was assessed using the numeric rating scale (NRS).
RESULTS: The HJS group showed higher NRS scores (p < 0.001). Headache, neck and shoulder girdle pain, and temporomandibular joint (TMJ) pain were found to be more severe in almost each patient from the HJS group as compared to CG. Those individuals had a greater degree of disability on the TMD-Q and the NDI scales (p < 0.001). The HJS group showed significant positive correlations between the TMD-Q and NDI scores (p = 0.0035), and between the TMD-Q and TMJ symptom questionnaire scores (p = 0.0047). A significant positive correlation between the NDI and TMJ symptom questionnaire scores was found both in the HJS group (p < 0.001) and CG (p < 0.001).
CONCLUSIONS: The HJS bearers tended to obtain higher TMJ and cervical spine disability scores, at the same time reporting increased headache, neck and shoulder girdle pain, and TMJ pain intensity. Therefore TMJs should be carefully examined for possible signs of dysfunction in HJS subjects prior to dental or prosthetic treatment. According to our data, TMJ and cervical spine disability assessment should be included as a routine practice in the case of HJS patients, who should remain under the long-term care of a multidisciplinary team of doctors and therapists.

UNASSIGNED: Varus and valgus knee stress radiographs provide valuable information in the pre- and postoperative evaluation of joint laxity in patients with multiligament knee injuries (MLKIs).
UNASSIGNED: To review the literature for described techniques of quantifying laxity on coronal stress radiographs of the knee and identify the most reliable method.
UNASSIGNED: Cohort study (diagnosis); Level of evidence, 3.
UNASSIGNED: A thorough literature search using the MEDLINE and Embase databases identified 4 studies with distinct methods for objectively measuring laxity on varus and valgus stress radiographs: Heesterbeek et al (2008), Jacobsen (1976), LaPrade et al (2004), and Sawant et al (2004). To compare these methods, 200 coronal plane stress radiographs from 50 patients with MLKIs were retrospectively reviewed from an MLKI database at a single institution. The amount of varus and valgus laxity on each radiograph was measured independently by 4 reviewers using each method. Intraclass correlation coefficients (ICCs) with 95% CIs were calculated to assess the interobserver reliability of each method overall and the varus and valgus measurements individually.
UNASSIGNED: For all 4 methods, the overall interobserver reliability was considered at least moderate. The method by Heesterbeek et al proved to have the highest interrater reliability in all domains-overall (ICC, 0.87 [95% CI, 0.85-0.90]), valgus (ICC, 0.83 [95% CI, 0.78-0.88]), and varus (ICC, 0.87 [95% CI, 0.83-0.90])-demonstrating good to excellent reliability both overall and in varus measurements and showing good reliability in valgus measurements. The method by Sawant et al demonstrated good reliability in valgus measurements. All other measures demonstrated moderate reliability.
UNASSIGNED: Available methods for measuring knee joint laxity on varus and valgus knee stress radiographs in patients with MLKIs demonstrated moderate to good interobserver reliability. The method described by Heesterbeek et al proved to have the highest reliability overall as well as in measurements on varus and valgus views individually.

Objective This study aimed to investigate the relationship between joint laxity and post-dural puncture headache (PDPH). Methods A total of 123 patients with PDPH - 73 females and 50 males - were included in the study. The patients were examined regarding joint laxity and classified into two groups according to the Beighton score. Those with a Beighton score between 0 and 3 were classified as Group I, and those with a score greater than 4 were classified as Group II. Data related to the demographic characteristics of the patients, time of onset of PDPH, severity, need for medical treatment, need for an epidural blood patch, and length of hospital stay were recorded, and a comparison was made between the two groups. Results There was no significant difference between the groups in terms of age, gender distribution, and PDPH onset time (p>0.05). In Group II, which included patients positive for joint laxity, total headache duration, headache severity, need for medical treatment, need for epidural blood patch, and hospital stay were significantly higher than in Group I (p<0.05). Conclusion Joint laxity may increase the risk of PDPH after spinal anesthesia and may affect treatment processes. The Beighton score can determine the development and severity of PDPH in patients with joint laxity. Assessing joint laxity and Beighton score can improve clinical decision-making in managing PDPH and positively affect patient outcomes.

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.

Bi-cruciate retaining total knee arthroplasty with an asymmetrical design may improve knee function and clinical outcomes. This study aimed to compare the kinematics, anteroposterior laxity, and in situ forces of the anterior and posterior cruciate ligaments of knees subjected to this treatment with those of healthy knees.
Seven fresh-frozen cadaveric knees were tested using a robotic/universal force-moment sensor system. The kinematics during passive flexion-extension motion and anteroposterior laxity for native knee, treated knee, and treated knee with cruciate ligament transection states were investigated. The motions of the intact and treated knees during each test were repeated after anterior/posterior cruciate ligament transection to calculate the in situ force in the ligaments.
The screw-home movement of normal knees disappeared after treatment. The in situ force of the anterior cruciate ligament in treated knees was higher than that in intact knees at ˃15° during flexion and at 60° and 90° against an anterior force. The in situ force of the posterior cruciate ligament in treated knees was higher at 0°, 15°, and 30° during flexion and at all flexion angles against a posterior force.
The screw-home movement of normal knees decreased, and the in situ force of the anterior and posterior cruciate ligaments increased after treatment.

BACKGROUND: Painful habitual instability of the thumb basal joint (PHIT) is a rarely diagnosed condition that can severely impair hand function. Furthermore, it can increase the risk of developing carpometacarpal arthritis of the thumb (CMAOT). Clinical examination and radiographic imaging provide the foundation for a correct diagnosis, but early detection is still challenging. We investigated two objective, radiographically obtainable parameters as potential risk factors for PHIT.
METHODS: Clinical data and radiographic images of 33 patients suffering from PHIT were collected and compared to those of 35 people serving as the control group. The two main objectives, the slope angle and the bony offset of the thumb joint, were gathered from the X-rays and statistically analyzed.
RESULTS: The analysis showed no differences between the study and the control group concerning the slope angle. Gender and the bony offset, on the other hand, had a significant influence. Female sex and higher offset values were associated with an increased risk of PHIT.
CONCLUSIONS: The results of this study prove a connection between a high bony offset and PHIT. We believe this information can be valuable in early detection and will allow more efficient treatment of this condition in the future.

Cranial cruciate ligament deficiency (CCLD) results in internal rotational instability of the stifle (RLS). By contrast, tibial torsion (TT) is an anatomical feature of the tibia along its longitudinal axis. The objective of this study was to validate a dynamic radiographic technique to measure internal rotational laxity of the stifle and differentiate it from TT. Models included transection of the CCL for RLS and an osteotomy for TT. One limb within eight pairs of canine cadaveric hind limbs was randomly assigned to CCLD. The contralateral limb underwent TT, followed by CCLD. Neutral and stress radiographs were taken with the limb in a custom rotating 3-D printed positioning device before and after each modification. The position of the calcaneus on neutral views and the magnitude of its displacement under standardized torque were compared within limbs and between groups. Transection of the CCL increased the magnitude of displacement of the calcaneus by 1.6 mm (0.3-3.1 mm, p < 0.05) within limbs. The lateral calcaneal displacement (dS-dN) tended to be greater when CCLD limbs were compared to limbs with intact CCL. A magnitude of calcaneal displacement of 3.45 mm differentiated limbs with RLS from intact limbs with 87.5% sensitivity and 68.7% specificity. The calcaneus was displaced further laterally by about 3 mm on neutral radiographs (dN) when limbs with experimental TT were compared to those without TT (p < 0.05). A calcaneus located at least 3.25 mm from the sulcus differentiated limbs with TT from intact limbs with 87.5% sensitivity and 87.5% specificity. The technique reported here allowed detection of RLS, especially within limbs. A calcaneus located at least 3.25 mm on neutral radiographs of large dogs should prompt a presumptive diagnosis of TT.

BACKGROUND: The purpose of this study was to systematically review the literature to understand the contemporary outcomes for patients with joint laxity managed with hip arthroscopy.
METHODS: A search was performed utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement guidelines. All literature related to joint laxity in hip arthroscopy patients was identified. Inclusion criteria consisted of patient-reported outcomes and Beighton and Horan Joint Mobility Index scoring. Study quality was assessed using the Methodological Index of Non-Randomized Studies criteria.
RESULTS: Seven articles were identified, including 412 patients (416 hips). Patients were predominantly female (range 83-100%). Mean patient age ranged from 13-69 years. Five studies consisting of 370 hips reported a range of 75 to 100% undergoing labral repair, 0 to 13% labral debridement, 0 to 7% labral reconstruction, 43 to 100% capsular closure, 94 to 99% femoroplasty, 3 to 80% rim resection, and 9 to 50% subspine decompression for surgical management. Post-operative follow-up range was 6-99 months. The mean range of improvement in Hip Outcomes Score Activities of Daily Living, Hip Outcomes Score-Sports Subscale, modified Harris Hip Score, Visual Analog Scale, and 12 item Short Form Health Survey were 17.6-31.3, 31.3-35.1, 22.5-53.8, - 2.79-8, and 12.4-16.9 respectively.
CONCLUSIONS: Generalized ligamentous laxity patients managed with hip arthroscopy were predominantly young women. At short-term follow-up, mean patient-reported outcomes were positive, with improvement postoperatively in activities of daily living, sports, and quality of life.

BACKGROUND: Posterior-stabilized (PS)-total knee arthroplasty (TKA) arose as an alternative to cruciate-retaining (CR)-TKA in the 1970s. Since then, it has become a popularly utilized TKA design with outcomes comparable to CR-TKA. The post-cam mechanism is unique to PS-TKA as it substitutes the function of the posterior cruciate ligament (PCL). The study aimed to understand the kinematic and laxity changes in PS-TKA with under- and overstuffing of the tibiofemoral joint space with the polyethylene (PE) insert.
METHODS: This study employed a hybrid computational-experimental joint motion simulation on a VIVO 6 degrees of freedom (6-DoF) joint motion simulator (AMTI, Watertown, MA, USA). Physical prototypes of a virtually-performed TKA in mechanical alignment (MA) and kinematic alignment (KA) based on cadaveric CT scans and a virtual ligament model were utilized. The reference, understuffed (down 2 mm) and overstuffed (up 2 mm) joint spaces were simulated, neutral flexion and laxity testing loads and motions were performed for each configuration.
RESULTS: The PE insert thickness influenced post-cam engagement, which occurred after 60º in the overstuffed configurations, after 60º-75º in the reference configurations and after 75º in the understuffed configurations. The understuffed configurations, compared to the reference configurations, resulted in a mean 2.0º (28%) and 2.0º (31%) increase in the coronal laxity in MA and KA respectively. The overstuffed configurations, compared to the reference configuration, resulted in an increase in the mean joint compressive forces (JCFs) by 73 N (61%) and 77 N (62%) in MA and KA models, respectively.
CONCLUSIONS: The under- and overstuffing in PS-TKA alter the kinematics with variable effects. Understuffing decreases the stability, JCFs and inverse with overstuffing. Subtle changes in the PE insert thickness alter the post-cam mechanics.