Biomechanical considerations in the pathogenesis of osteoarthritis of the knee

Osteoarthritis is the most common joint disease and a major cause of disability. The knee is the large joint most affected. While chronological age is the single most important risk factor of osteoarthritis, the pathogenesis of knee osteoarthritis in the young patient is predominantly related to an unfavorable biomechanical environment at the joint. This results in mechanical demand that exceeds the ability of a joint to repair and maintain itself, predisposing the articular cartilage to premature degeneration. This review examines the available basic science, preclinical and clinical evidence regarding several such unfavorable biomechanical conditions about the knee: malalignment, loss of meniscal tissue, cartilage defects and joint instability or laxity

Meniscal and articular cartilage lesions in the anterior cruciate ligament-deficient knee: correlation between time from injury and knee scores

Anterior cruciate ligament (ACL) rupture is associated with meniscal tears and/or articular cartilage damage. The aim of this study was twofold: (a) to report and correlate the incidence of meniscal and cartilage lesions in ACL-deficient knees with time from injury and (b) to correlate lesions of menisci and cartilage with widely used knee scores. Data were analysed from 109 consecutive patients with ACL rupture. Meniscal and articular cartilage lesions were documented during the arthroscopic reconstruction of the ACL. Patients were distributed into 3 groups according to time from injury; group A: 0-3 months (35 patients), group B: 3-12 months (39 patients) and group C: more than 12 months (35 patients). Lysholm, KOOS and IKDC rating scales were recorded preoperatively. Logistic regression analyses were applied to correlate the concomitant intra-articular pathologies with the time from injury and knee-rating scales. Of 109 patients, 32 (29 %) had a medial meniscus tear, 20 (19 %) had a lateral meniscus tear, 17 (15 %) had both menisci torn and 40 (37 %) had no meniscal tear. Analysis revealed that time from injury was not a significant factor for the presence of a meniscal lesion. The odds of development of a high-grade cartilage lesion in an ACL-deficient knee reconstructed more than 12 months from time from injury are 5.5 and 12.5 times higher when compared with knees that underwent ACL reconstruction less than 3 months and between 3 and 12 months after knee injury, respectively. No association was found between intra-articular pathology and the KOOS and Lysholm scores. A positive correlation between the IKDC score and patients without any intra-articular pathology was found. The presence of high-grade cartilage lesions is significantly increased in an ACL-deficient knee when reconstruction is performed more than 12 months after injury. However, the incidence of meniscal tears is not increased significantly. Correlation of intra-articular pathology in ACL-deficient knees with knee-rating scales is weak. Diagnostic study, Level II