Kazuhiko Saeki

Stability After Medial Collateral Ligament Release in Total Knee Arthroplasty

Six knees from cadavers were tested for change in stability after release of the medial collateral ligament with posterior cruciate-retaining and substituting total knee replacements. Load deformation curves of the joint were recorded in full extension and 30°, 60°, and 90° flexion under a 10 N-m varus and valgus torque, 1.5 N-m internal and external rotational torque, and a 35 N anterior and posterior force to test stability in each knee. The intact specimen and posterior cruciate ligament-retaining total joint replacement were tested for baseline comparisons. The superficial medial collateral ligament was released, followed by release of the posterior cruciate ligament. The knee then was converted to a posterior-stabilized implant. After medial collateral ligament release, valgus laxity was statistically significantly greater at 30°, 60°, and 90° flexion after posterior cruciate ligament sacrifice than it was when the posterior cruciate ligament was retained. The posterior-stabilizing post added little to varus and valgus stability. Small, but significant, differences were seen in internal and external rotation before and after posterior cruciate ligament sacrifice. The posterior-stabilized total knee arthroplasty was even more rotationally constrained in full extension than the knee with intact medial collateral ligament and posterior cruciate ligament.

Effect of Medial Epicondylar Osteotomy on Soft Tissue Balancing in Total Knee Arthroplasty

Balancing and surgical exposure of a severe varus knee during total knee arthroplasty (TKA) can be difficult. Use of a medial epicondylar osteotomy to solve these problems has been reported. This study compared knee stability in cadaveric specimens after TKA, after medial epicondylar osteotomy, and after conventional subperiosteal release of the medial collateral ligament (MCL). Five cadaveric knees were tested after TKA, after medial epicondylar osteotomy, and after repair of the osteotomy to compare the results to 5 cadaveric knees that underwent complete subperiosteal release of the MCL. A retrospective review of clinical cases also was performed of 118 varus knees exposed using the standard medial parapatellar approach and subperiosteal release of the MCL to compare results to the literature using a medial epicondylar osteotomy. Coronal and transverse plane laxity increased significantly at 60° and 90° flexion in the knees after medial epicondylar osteotomy. Suture repair of the osteotomy did not affect stability. The knees with MCL release had a significantly lower degree of coronal and transverse plane laxity at 60° and 90° than knees with an epicondylar osteotomy. The retrospective case review found satisfactory exposure and correct ligament balance was achieved in all cases. The findings of this study question the need for an epicondylar osteotomy in severe varus osteoarthritic knees. Because the knee remains unstable in flexion after this technique, an implant with higher constraint should be used.

Deformation of the patellofemoral joint caused by synovial hemangioma: a case report.

A 15-year-old girl with synovial hemangioma of the knee joint presented with gait pain and occasional sudden swelling for over 7 years. Plain radiographs showed an irregular joint line and a lateral shift of the patella caused by malformation of the patellar groove. Arthroscopy was performed to resect the tumor and to release the lateral patellar retinaculum. If the synovial hemangioma exists in the patellofemoral joint during the growth period, we propose that early surgical treatment is necessary to avoid the deformation of the joint.