ABSTRACT
Osteoarthritis is a common articular cartilage degenerative disease and the main cause is mechanical instability. The mechanical instability can reduce the number of chondrocytes and destroy extracellular matrix through direct injury, inducing cell apoptosis, and stimulating the production of inflammatory factors, leading to decrease of matrix typeⅡ collagen and proteoglycan and degeneration of cartilage. Long-term cartilage degeneration can result in osteoarthritis. Therefore, understanding how mechanical instability leads to the incidence of osteoarthritis can better improve the course of osteoarthritis from the perspective of mechanics.
ABSTRACT
Objective To evaluate the angle between the anterior talofibular ligament (ATFL) and posterior talofibular ligament (PTFL) in patients with mechanical ankle instability,so as to find out a new indirect diagnosis method for the chronic ATFL lesion.Methods One hundred subjects were included in this study,among which 50 patients with mechanical ankle instability were assigned to group A and 50 counterparts without it were selected into group B All patients were taken MR Images and the ATFL and PTFL angle at the axial plane was evaluated.The difference between two groups was evaluated.Results The ATFL and PTFL angle increased significantly in group A when compared to group B (82.1° ± 8.0° v.s,74.4° ± 5.9°,P＜0.01).The area under receiver operating characteristic curve (ROC)was 0.874 (P＜0.01),indicating great significance in diagnosing the chronic ATFL tear.Moreover,the angle was 79 degree,showing high sensitivity (0.88) and specificity (0.64) of diagnosing ATFL tear.Conclusion The ATFL and PTFL angle increases significantly in patients with the mechanical instability.Moreover,the possibility of ATFL tear increases when the ATFL and PTFL angle is greater than 79 degree.
ABSTRACT
Objective To analyze and evaluate the effect of posterior circumferential fusion for treatment of the mechanical instability of lumbar spine, and discuss the relative merits,indications and contraindications in this procedure. Methods Two hundred and two patients with mechanical instability of lumbar spine treated by the posterior instrumented circumferential fusion technique from January 2001 to January 2007. One hundred and thirty-two patients were selected who were treated with only one segment fusion and followed up for at least 1 year, of them 97 patients suffered lumbar spondylolisthesis, 35 patients suffered degenerative lumbar instability. X-ray was used to evaluate the fusion condition of the bone graft, and VAS and ODI questionnaire were applied to assess the pain of back and leg,and the conventional function. Results All patients were followed up for 12-84 months, averaged (43±23) months,125 patients got bone fusion, accounted for 94.7%(125/132). The VAS of low back pain was (6.71 ± 1.31) points before operation, while (3.20 ± 1.14) points after operation (P < 0.05) ,and the VAS of leg pain was (8.33 ± 1.78) points before operation,while (4.31 ± 1.15) points after operation (P< 0.05). The ODI was (68.6 ± 14.7) % before operation, while (13.6 ± 1.5) % after operation (P < 0.05). Conclusions Posterior circumferential fusion is a positive and excellent treatment for the mechanical instability of lumbar spine. With its merits, the high fusion rate and good clinical results can be received.