Intra-articular injection of magnesium chloride attenuates osteoarthritis progression in rats.

OBJECTIVE: To explore the effects of Mg2+ on the expression of osteoarthritic markers in human cartilage and synovium tissue explants. To investigate the therapeutic effect of intra-articular injection of Mg2+ in an established rat OA (Osteoarthritis) model of anterior cruciate ligament transection with partial medial meniscectomy (ACLT + PMM). DESIGN: Human cartilage and synovium explants were collected from total knee replacement surgeries and incubated with MgCl2 (20 mmol/L) in vitro. A rat OA model was established by ACLT + PMM surgery in 450-500 g male Sprague Dawley (SD) rats. To select the optimal dose, intra-articular injections of MgCl2 (0.05, 0.5, 5 mol/L) were performed at 4 weeks after the surgery every 3 days for 2 weeks. The effect of optimized MgCl2 was further determined by histology, immunohistochemistry, and quantitative real-time polymerase chain reaction. RESULTS: The expressions of osteoarthritic markers in human cartilage and synovium explants were inhibited by Mg2+in vitro. Immunohistochemical analysis further suggested the inhibitory effects of Mg2+ on the expression of MMP-13 and IL-6 in the human tissue explants. Cartilage degeneration and synovitis in ACLT + PMM rats were significantly improved by intra-articular injections of Mg2+ (0.5 mol/L). Immunohistochemical analysis also showed the regulatory effects of Mg2+ on osteoarthritic markers in both cartilage and synovium in rats, consistent with in vitro results. CONCLUSION: Intra-articular injections of Mg2+ at 0.5 mol/L attenuate the progression of OA in the ACLT + PMM rat model. Such effect was at least in part explained by the promotion of cartilage matrix synthesis and the suppression of synovial inflammation.

Arthroscopy-assisted computer navigation in high tibial osteotomy for varus knee deformity.

PURPOSE: To assess the accuracy of knee alignment after high tibial osteotomy (HTO) for varus knee deformity using arthroscopy-assisted computer navigation. METHODS: Six men and 4 women aged 47 to 53 (mean, 49) years underwent medial open wedge HTO for varus knee deformity and medial unicompartmental osteoarthritis using arthroscopy-assisted computer navigation with fluoroscopy. Patients were followed up for a mean of 23 (range, 11-32) months. Intra- and post-operative leg alignments were compared. RESULTS: The mean postoperative coronal plane alignment was 2.7 (range,1-4) degree valgus; the mean deviation from intra-operative computer images was one (range, 0.1-1.9) degree; 5 knees had less valgus in the postoperative radiographs than the intra-operative computer images. CONCLUSION: Despite being more technically demanding, time consuming, and costly, arthroscopy-assisted computer navigation is safe, accurate, and reliable for HTO.

Coracoclavicular ligament reconstruction using a gracilis tendon graft for acute type-III acromioclavicular dislocation.

PURPOSE: To review the functional and radiological results of patients after coracoclavicular ligament reconstruction. METHODS: Five patients aged 21 to 50 (mean, 37) years with acute Rockwood type-III acromioclavicular dislocation underwent coracoclavicular ligament reconstruction with autogenous gracilis tendon grafts. Patients were either active in sports or heavy manual workers. Assessments on shoulder function (using the Constant score), wound size, pain (using a visual analogue scale), and reduction (using radiographs of both acromioclavicular joints) were made. RESULTS: The mean follow-up period was 26 (range, 15-43) months; the mean time to return to work or sports was 14 (range, 12-20) weeks. The mean Constant score was 94 (range, 90-98). The mean donor-site scar size was 3 cm and the mean pain score was 0. No major complication or donor-site morbidity was noted. There was one subluxation. CONCLUSION: Coracoclavicular ligament reconstruction using an autogenous gracilis tendon graft was safe in physically active patients having acute type-III acromioclavicular dislocation.

Percutaneous intramedullary Kirschner wiring for displaced diaphyseal forearm fractures in children.

Displaced fractures of the forearm in children are often treated conservatively, but there is a relatively high incidence of redisplacement, malunion and consequent limitation of function. We have performed percutaneous Kirschner (K) wire fixation in 72 such children under the age of 14 years, of which 57 were reviewed for our study. Both the radius and ulna were fractured in 45 (79%), the radius only in eight and the ulna only in four. The mean initial angulation was 19 degrees in the lateral plane and 9 degrees in the anteroposterior plane for the radius and 15 degrees and 9 degrees, respectively, for the ulna. In 42 patients (74%) we performed closed reduction. In the remaining 15 (26%) closed reduction failed and an open reduction, through a minimal approach, was required before K wiring. At a mean follow-up of 20 months all patients had good functional results with an excellent range of movement. Only five had angulation of from 10 degrees to 15 degrees and none had nonunion, premature epiphyseal closure or deep infection. Percutaneous intramedullary K wiring for forearm diaphyseal fracture is a convenient, effective and safe operation, with minimal complications.