vendex and Osteochondritis-Dissecans

Contact between the tibial spine and medial femoral condyle with internal tibial rotation (ITR) has been proposed as a factor for the development of osteochondritis dissecans lesions. We hypothesized that tibial spine contact force (CF) would increase significantly with applied internal tibial torque (IT).. A 20 mm diameter cylinder of bone encompassing the tibial spine was cored and attached to a load cell. The isolated bone cylinder included the tibial attachments of the anterior cruciate ligament (ACL) and anterior horn of the lateral meniscus (AHLM). Eleven human cadaveric knees were flexed from 0°-50° under 200 N of tibiofemoral compression (TFC), without and with 2 N-m IT. Tests were repeated with the AHLM cut, and again with both AHLM and ACL cut, where the load cell recorded CF alone without contributions from any ligamentous attachments.. There were no significant differences in CF, ITR, or valgus tibial rotation (VTR) after sectioning the AHLM, without or with applied IT. With no tibial torque, mean CFs were less than 20 N throughout the flexion range. Addition of IT significantly increased 1) mean CF by 44.4 N(SD 15.8 N) at 0°(+240%) and 27.2 N(SD 5.0 N) at 20°(+675%), 2), mean ITR by 10.2°(SD 0.8°) at 0° flexion and 18.6°(SD 2.0°) at 20° flexion, and 3) mean VTR by 1.3°(SD 0.4°) at 0° flexion and 4.4°(SD 0.8°) at 20° flexion.. Our hypothesis was confirmed only between 0° and 20° of knee flexion, where the intercondylar separation distance is relatively small and the possibility of tibial spine contact with ITR is greater.

Topics: Anterior Cruciate Ligament; Biomechanical Phenomena; Cadaver; Femur; Humans; Knee Joint; Menisci, Tibial; Osteochondritis Dissecans; Rotation; Tibia; Torque

The repetitive, excessive compression forces in the radiocapitellar joint caused by elbow valgus stresses during throwing motions can result in osteochondritis dissecans (OCD) of the humeral capitellum in adolescent athletes.. To assess the effect of elbow valgus torque on contact pressure in the radiocapitellar joint and that of central and lateral capitellar osteochondral defects on radiocapitellar joint contact pressure, elbow valgus laxity, and ulnar collateral ligament (UCL) strain.. Controlled laboratory study.. In 8 matched pairs of fresh-frozen cadaveric upper limbs, lateral osteochondral defects of the humeral capitellum (5-, 10-, 15-, and 20-mm diameters) were evaluated in one side, and central defects were evaluated in the contralateral side. Radiocapitellar joint contact pressure, elbow valgus laxity, and UCL strain were all measured with and without 2 N·m of valgus torque at 30°, 60°, and 90° of elbow flexion in neutral forearm rotation.. Applying valgus torque increased contact pressure in radiocapitellar joints with intact or damaged capitula. Contact pressure in joints with 15-mm (90° of elbow flexion) and 20-mm (60° and 90° of elbow flexion) lateral capitellar defects was greater than that in joints with intact capitula. Radiocapitellar contact pressure was greater with a 20-mm lateral capitellar defect than in the same-sized central defect at 60° and 90° of elbow flexion. In both central and lateral defect groups, elbow valgus laxity increased as the size of the capitellar defect increased, and UCL strain remained unchanged regardless of the size of the capitellar defect.. Elbow valgus torque increases contact pressure in the radiocapitellar joint. Capitellar osteochondral defects increase elbow valgus laxity and contact pressure without increasing UCL strain. When valgus torque is applied, contact pressure in the radiocapitellar joint is greater with a lateral defect than with a central defect.. Adolescent baseball players with capitellar OCD should stop throwing, even if the UCL is intact, to prevent exacerbating the osteochondral defect. Lateral capitellar OCD is more severe than central capitellar OCD.

Topics: Baseball; Biomechanical Phenomena; Collateral Ligaments; Cumulative Trauma Disorders; Elbow Injuries; Elbow Joint; Female; Humans; Humerus; Joint Instability; Male; Osteochondritis Dissecans; Pressure; Torque