Explore the vast range of titles available.

Distribution of strain through the thickness of articular cartilage, or transchondral strain, is highly dependent on the geometry of the joint involved. Excessive transchondral strain can damage the solid matrix and ultimately lead to osteoarthritis. Currently, high-resolution transchondral strain distribution is unknown in the human hip. Thus, knowledge of transchondral strain patterns is of fundamental importance to interpreting the patterns of injury that occur in prearthritic hip joints. This study had three main objectives. We sought to 1) quantify high-resolution transchondral strain in the native human hip, 2) determine differences in transchondral strain between static and dynamic loading conditions to better understand recovery and repressurization of cartilage in the hip, and 3) create finite element (FE) models of the experimental testing to validate a modeling framework for future analysis. The transchondral strain patterns found in this study provide insight on the localization of strain within cartilage of the hip. Most notably, the chondrolabral junction experienced high tensile and shear strain across all samples, which explains clinical data reporting it as the most common region of damage in cartilage of the hip. Further, the representative FE framework was able to match the experimental static results and predict the dynamic results with very good agreement. This agreement provides confidence for both experimental and computational measurement methods and demonstrates that the specific anisotropic biphasic FE framework used in this study can both describe and predict the experimental results.

Osteoarthritis of the hip can result from mechanical factors, which can be studied using finite element (FE) analysis. FE studies of the hip often assume there is no significant loss of fluid pressurization in the articular cartilage during simulated activities and approximate the material as incompressible and elastic. This study examined the conditions under which interstitial fluid load support remains sustained during physiological motions, as well as the role of the labrum in maintaining fluid load support and the effect of its presence on the solid phase of the surrounding cartilage. We found that dynamic motions of gait and squatting maintained consistent fluid load support between cycles, while static single-leg stance experienced slight fluid depressurization with significant reduction of solid phase stress and strain. Presence of the labrum did not significantly influence fluid load support within the articular cartilage, but prevented deformation at the cartilage edge, leading to lower stress and strain conditions in the cartilage. A morphologically accurate representation of collagen fibril orientation through the thickness of the articular cartilage was not necessary to predict fluid load support. However, comparison with simplified fibril reinforcement underscored the physiological importance. The results of this study demonstrate that an elastic incompressible material approximation is reasonable for modeling a limited number of cyclic motions of gait and squatting without significant loss of accuracy, but is not appropriate for static motions or numerous repeated motions. Additionally, effects seen from removal of the labrum motivate evaluation of labral reattachment strategies in the context of labral repair.

There is a mean incidence of osteoarthritis (OA) of the hip in 8% of the overall population. In the presence of focal chondral defects, defined as localized damage to the articular cartilage, there is an increased risk of symptomatic progression toward OA. This relationship between chondral defects and subsequent development of OA has led to substantial efforts to develop effective procedures for surgical cartilage repair. This study examined the effects of chondral defects and labral delamination on cartilage mechanics in the dysplastic hip during the gait cycle using subject-specific finite element analysis. Models were generated from volumetric CT data and analyzed with simulated chondral defects at the chondrolabral junction on the posterior acetabulum during five distinct points in the gait cycle. Focal chondral defects increased maximum shear stress on the osteochondral surface of the acetabular cartilage, when compared to the intact case. This effect was amplified with labral delamination. Additionally, chondral defects increased the first principal Lagrange strain on the articular surface of the acetabular cartilage and labrum. Labral delamination relieved some of this tensile strain. As defect size was increased, contact stress increased in the medial zone of the acetabulum, while it decreased anteriorly. The results suggest that in the presence of chondral defects and labral delamination the cartilage experiences elevated tensile strains and shear and contact stress, which could lead to further damage of the cartilage, and subsequent arthritic progression. The framework presented here will serve as the procedure for future finite element studies on cartilage mechanics in hips with varying disease states with simulated chondral defects and labral tears.

Knee cartilage does not regenerate spontaneously after injury, and a gold standard regenerative treatment algorithm has not been established. This study demonstrates preclinical safety and efficacy of scaffold-free, human juvenile cartilage-derived-chondrocyte (JCC) sheets produced from routine surgical discards using thermo-responsive cultureware. JCCs exhibit stable and high growth potential in vitro over passage 10, supporting possibilities for scale-up to mass production for commercialization. JCC sheets contain highly viable, densely packed cells, show no anchorage-independent cell growth, express mesenchymal surface markers, and lack MHC II expression. In nude rat focal osteochondral defect models, stable neocartilage formation was observed at 4 weeks by JCC sheet transplantation without abnormal tissue growth over 24 weeks in contrast to the nontreatment group showing no spontaneous cartilage repair. Regenerated cartilage was safranin-O positive, contained type II collagen, aggrecan, and human vimentin, and lacked type I collagen, indicating that the hyaline-like neocartilage formed originates from transplanted JCC sheets rather than host-derived cells. This study demonstrates the safety of JCC sheets and stable hyaline cartilage formation with engineered JCC sheets utilizing a sustainable tissue supply. Cost-benefit and scaling issues for sheet fabrication and use support feasibility of this JCC sheet strategy in clinical cartilage repair.

Background Multiligament knee injuries (MLKIs) often result from high-energy trauma in polytrauma patients. They may coincide with other musculoskeletal injuries, especially fractures of the ipsilateral lower extremity (LE) or pelvis. Understanding these fracture patterns can guide surgical planning and improve patient outcomes. The study aim is to describe the ligamentous injury patterns of combined ipsilateral LE or pelvic fractures with surgically treated MLKIs. Methods A retrospective cohort study was conducted from April 2008 to August 2024. Patients who sustained tibial plateau (TP), femoral condyle (FC), fibular, tibial shaft, femoral shaft, or pelvic fractures, concurrent with surgically treated MLKIs, were included. Ligament injuries (anterior cruciate [ACL], posterior cruciate [PCL], medial collateral [MCL], and lateral collateral [LCL]) were categorized by number (≥ 2) and pattern (ACL-based, PCL-based, or bicruciate). Comparisons were made between fracture and non-fracture groups. Results Among 211 patients (69% male; mean age 28.3 ± 12.9 years), 36% (75/211) had fractures, with 19% (17/75) requiring operative fixation. TP fractures were the most common (57%), followed by FC (47%) and pelvic fractures (16%). ACL-based injuries (65%) were predominant, while PCL-based injuries were less frequent in fracture patients (4% versus 13% in the non-fracture group). ACL/LCL injuries were significantly more common in the fracture group (29% versus 18%, p  = 0.049). Two-ligament injuries accounted for 71% (53/75) of fracture cases. Conclusions More than one-third of patients with MLKI sustained concomitant LE fractures, with TP fractures occurring most frequently. ACL/LCL and ACL/PCL/LCL patterns showed particularly high fracture rates, whereas PCL-based MLKIs were more common without fractures.

Background: The lateral center-edge angle (LCEA) is an important measurement in understanding acetabular morphology and has had multiple interpretations. Misunderstanding of the LCEA and its relationship with acetabular 3-dimensional (3D) morphology may result in misdiagnosis and poor outcomes. Purpose: To determine the discrepancy between bone-edge and sourcil-edge LCEA measurements on anteroposterior (AP) radiographs and to determine the 3D anatomic location of the sourcil-edge and bone-edge LCEA measurements. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The LCEA was measured on radiographs to both the sourcil-edge and bone-edge on AP images of 60 symptomatic hips. On computed tomography (CT), coronal slices producing an LCEA matching the magnitude of each AP LCEA were identified. These coronal slices were mapped to a sagittal image of the acetabulum, which was divided into a standard clockface (3 = anterior, 12 = superior). We identified clockface locations corresponding to the AP sourcil-edge and bone-edge LCEA measurements. Paired t tests identified differences in magnitude and location of the bone and sourcil LCEAs. Limits of agreement were calculated for the differences between measures. Intraclass correlation coefficients (ICCs) assessed inter- and intraobserver repeatability. Results: On the AP radiographs, the bone-edge LCEA was a mean 4.7° (95% CI, −4.0° to 13.3°) greater than the sourcil-edge LCEA (P < .001). On CT, the sagittal clockface location of the sourcil-edge LCEA was more anterior compared with the sagittal clockface location of the maximum bone-edge LCEA (1:03 ± 0:42 vs 12:06 ± 0:30, respectively; P < .001). In hips with a difference >5° between sourcil-edge and bone-edge measurements, the coronal CT slice corresponding to the sourcil-edge LCEA was significantly more anterior (1:26 ± 0:35) than the CT slice corresponding to the bone-edge LCEA (11:46 ± 0:29; P < .001). This significant difference was similar in location but less pronounced in hips with a difference ≤5°: the sourcil-edge LCEA occurred at 12:50 ± 0:40, while the bone-edge LCEA occurred at 12:00 ± 0:11 (P < .001). Interobserver repeatability was excellent for all LCEA and clockface location measurements (all ICCs >0.82). Conclusion: The sourcil-edge LCEA represents anterosuperior acetabular coverage while the bone-edge LCEA represents superior/lateral coverage. This information can be used in preoperative evaluation of and perioperative planning for hip preservation procedures.

Calcific tendinitis is a term used to describe radiographic evidence of calcific deposition within a tendon. This condition, also known as calcium deposition disease, has been described in the gluteus maximus, the peroneus longus tendon, the popliteus tendon, the longus colli muscle in the neck, and the tendon of the rectus femoris. However, most of the literature on calcific tendinitis relates to crystal deposition within the rotator cuff of the shoulder. The peri-articular pain related to calcium deposition may be indolent and chronic, and patients can have varying degrees of functional deficit. Patients also may present with an acute inflammatory event, with severe incapacitation and restricted passive range of motion and a clinical picture that is concerning for septic arthritis. Severe pain associated with calcific tendonitis usually occurs during the resorptive phase, where there is vascular infiltration of the calcium deposits and histologic evidence of phagocytosis. The authors report a case of calcium deposition disease found within the hip labrum with a clinical presentation of acute, atraumatic, debilitating pain in a patient with underlying femoroacetabular impingement. This clinical picture is similar to that described during the resorptive phase seen in calcific tendonitis of the shoulder. The authors attribute this presentation to acute rupture of the calcium deposit into the intra-articular joint space of the hip. To the authors’ knowledge, there are no other reports of this clinical presentation in the literature. [Calcific tendinitis is a term used to describe radiographic evidence of calcific deposition within a tendon. This condition, also known as calcium deposition disease, has been described in the gluteus maximus, the peroneus longus tendon, the popliteus tendon, the longus colli muscle in the neck, and the tendon of the rectus femoris. However, most of the literature on calcific tendinitis relates to crystal deposition within the rotator cuff of the shoulder. The peri-articular pain related to calcium deposition may be indolent and chronic, and patients can have varying degrees of functional deficit. Patients also may present with an acute inflammatory event, with severe incapacitation and restricted passive range of motion and a clinical picture that is concerning for septic arthritis. Severe pain associated with calcific tendonitis usually occurs during the resorptive phase, where there is vascular infiltration of the calcium deposits and histologic evidence of phagocytosis. The authors report a case of calcium deposition disease found within the hip labrum with a clinical presentation of acute, atraumatic, debilitating pain in a patient with underlying femoroacetabular impingement. This clinical picture is similar to that described during the resorptive phase seen in calcific tendonitis of the shoulder. The authors attribute this presentation to acute rupture of the calcium deposit into the intra-articular joint space of the hip. To the authors’ knowledge, there are no other reports of this clinical presentation in the literature. [ Orthopedics. 2014; 37(12):e1137–e1140.]

Purpose Develop a framework to quantify the size, location and severity of femoral and acetabular-sided cartilage and labral damage observed in patients undergoing hip arthroscopy, and generate a database of individual defect parameters to facilitate future research and treatment efforts. Methods The size, location, and severity of cartilage and labral damage were prospectively collected using a custom, standardized post-operative template for 100 consecutive patients with femoroacetabular impingement syndrome. Chondrolabral junction damage, isolated intrasubstance labral damage, isolated acetabular cartilage damage and femoral cartilage damage were quantified and recorded using a combination of Beck and ICRS criteria. Radiographic measurements including alpha angle, head–neck offset, lateral centre edge angle and acetabular index were calculated and compared to the aforementioned chondral data using a multivariable logistic regression model and adjusted odd’s ratio. Reliability among measurements were assessed using the kappa statistic and intraclass coefficients were used to evaluate continuous variables. Results Damage to the acetabular cartilage originating at the chondrolabral junction was the most common finding in 97 hips (97%) and was usually accompanied by labral damage in 65 hips (65%). The width ( p  = 0.003) and clock-face length ( p  = 0.016) of the damaged region both increased alpha angle on anteroposterior films. 10% of hips had femoral cartilage damage while only 2 (2%) of hips had isolated defects to either the acetabular cartilage or labrum. The adjusted odds of severe cartilage ( p  = 0.022) and labral damage ( p  = 0.046) increased with radiographic cam deformity but was not related to radiographic measures of acetabular coverage. Conclusions Damage at the chondrolabral junction was very common in this hip arthroscopy cohort, while isolated defects to the acetabular cartilage or labrum were rare. These data demonstrate that the severity of cam morphology, quantified through radiographic measurements, is a primary predictor of location and severity of chondral and labral damage and focal chondral defects may represent a unique subset of patients that deserve further study. Level of evidence IV.

Injury management is critical in the National Basketball Association (NBA), as players experience a wide variety of injuries. Recently, it has been suggested that game schedules, such as back-to-back games and four games in five days, increase the risk of injuries in the NBA. The aim of this study was to examine the association between game schedules and player injuries in the NBA. Descriptive epidemiology study. The present study analyzed game injuries and game schedules in the 2012–13 through 2014–15 regular seasons. Game injuries by game schedules and players’ profiles were examined using an exact binomial test, the Fisher’s exact test and the Mann–Whitney–Wilcoxon test. A Poisson regression analysis was performed to predict the number of game injuries sustained by each player from game schedules and injured players’ profiles. There were a total of 681 cases of game injuries sustained by 280 different players during the three years (total N=1443 players). Playing back-to-back games or playing four games in five days alone was not associated with an increased rate of game injuries, whereas a significant positive association was found between game injuries and playing away from home (p<0.05). Playing back-to-back games and away games were significant predictors of frequent game injuries (p<0.05). Game schedules could be one factor that impacts the risk of game injuries in the NBA. The findings could be useful for designing optimal game schedules in the NBA as well as helping NBA teams make adjustments to minimize game injuries.