الملخص
BACKGROUND:Reconstruction of the medial patellofemoral ligament is the primary and basic treatment for patellofemoral dislocation.Generally,autologous or allogeneic tendons are used to fix the patellofemoral podogram area and the femoral insertion,respectively.There are various fixation methods.Patellar lateral insertion fixation methods are relatively diverse,mainly traditional transosseous fixation and recent anchoring methods,including single tunnel,double-tunnel transosseous fixation,and two-wire anchor fixation.However,which fixation method is more effective in reducing patellofemoral joint stress and is more biomechanical has not been determined. OBJECTIVE:To observe the mechanical effects of patellofemoral joint and medial patellofemoral ligament reconstruction with transosseous and wire anchor fixation. METHODS:A three-dimensional finite element model of the knee joint was constructed.The medial patellofemoral ligament was reconstructed by a single tunnel through the bony canal or two wire anchors at the medial edge of the patella.The femoral side was fixed by extrusion nails to the medial epicondyle of the femur and the midpoint of the adductor tubercle.We observed the effects of the two fixation methods on patellofemoral joint and medial patellofemoral ligament loading during knee flexion at 0°,30°,60°,90°,and 120°. RESULTS AND CONCLUSION:(1)The stress on the patellofemoral joint was large when the knee was at flexion of 0-60°,peaked at 30°,and gradually decreased at 90° and 120°.The two fixation methods had little difference in the stress on the patellofemoral joint.(2)The stress on the medial patellofemoral ligament peaked at 30° and decreased significantly at 60°,and the load on the medial patellofemoral ligament was significantly greater at all angles with anchor fixation than with bony canal fixation.(3)The results showed that there was no significant difference in patellofemoral joint loading between the two fixation methods,but the stress on the medial patellofemoral ligament in anchoring was significantly greater than that in transosseous fixation.
الملخص
OBJECTIVE@#To investigate early effectiveness of arthroscopic superior fulcrum reconstruction in the treatment of irreparable massive rotator cuff tear (IMRCT).@*METHODS@#A retrospective analysis was conducted on the clinical data of 24 patients with IMRCT who met the inclusion criteria between January 2020 and April 2022. Among them, there were 11 males and 13 females with an average age of 56.2 years (range, 42-68 years). There were 12 cases of falling injuries, 3 cases of traction injuries, and the other 9 cases had no obvious causes. The disease duration ranged from 1 to 25 months (median, 6 months). The rotator cuff tears were classified as Hamada grade 2 in 18 cases and grade 3 in 6 cases, and Goutallier grade 1 in 3 cases, grade 2 in 20 cases, and grade 3 in 1 case. All patients were treated with arthroscopic superior fulcrum reconstruction. Visual analogue scale (VAS) score, Constant-Murley score, the University of California at Los Angeles (UCLA) score, and the American Shoulder and Elbow Surgeons (ASES) score were recorded before operation and at 1, 3, 6, and 12 months after operation.@*RESULTS@#The operations were all successfully completed. The incisions healed by first intention and no related complications occurred. All patients were followed up 12-33 months (mean, 24.6 months). The VAS, Constant-Murley, UCLA, and ASES scores at different time points after operation were superior to those before operation ( P<0.05). All of the above indicators further improved with time. Except for no significant difference in VAS and Constant-Murley scores between 6 and 12 months ( P>0.05), the differences between the other time points were significant ( P<0.05). At 12 months after operation, according to UCLA scoring standard, shoulder joint function was rated as excellent in 4 cases, good in 19 cases, and poor in 1 case, with an excellent and good rate of 96.0%. MRI showed that there was no graft re-tear and the transplanted tendon and bone tunnel healed.@*CONCLUSION@#The arthroscopic superior fulcrum reconstruction for IMRCT can effectively relieve the pain, improve the shoulder range of motion, and restore good shoulder function.