ABSTRACT:The anatomical structure at bone-tendon and bone-ligament interfaces is called the enthesis. Histologically, the enthesis is characterized by a transitional series of tissue layers from the end of the tendon to bone, including tendon, fibrocartilage, calcified fibrocartilage, and bone. This arrangement yields stronger direct connection of the soft tissues to bone. In surgical repair, the enthesis has proven difficult to reproduce, and the success of ligament-bone bonding has depended on the fibrous attachment that forms after any ligament reconstructions. In this study, we attempted to generate a direct-insertion enthesis in two stages. First, recombinant human bone morphogenetic protein-2 (rhBMP-2) was injected into the flexor digitorum communis tendon in the rabbit hind limb to induce ectopic ossicle formation. In a second step, the resultant tendon/ossicle complex was then surgically transferred onto the surface of the rabbit tibia to generate a stable tendon-bone junction. One month following surgery, histomorphological examination confirmed direct insertion of tendon-bone structures in the proximal tibia of the rabbit. Ultimate failure loads of the BMP-2-generated tendon-bone junction were significantly higher than in the control group ( p < 0.01). These findings suggest that it is possible to successfully regenerate a direct tendon-tobone enthesis. Use of this approach may enable successful reconstruction of joints rendered unstable after ligamentous rupture or laxity after anterior cruciate ligament injury. ß

MD provided similar or slightly better clinical outcomes with less complication as compared to DV. For athletes, the rate of return to sports was higher and the duration to return to sports was significantly shorter in the MD group.

The movement of the posterior cruciate ligament (PCL) during flexion of the living knee is unknown. The purpose of the present study was to analyze the movement of the PCL using magnetic resonance imaging (MRI). The posterior cruciate ligaments in 20 normal knees were visualized using MRI from extension to deep flexion. Sagittal inclination relative to the longitudinal axis of the tibia was measured and analyzed with reference to the patellar tendon (PT) and the anterior cruciate ligament (ACL). Although the PCL was slack in extension, it straightened with anterior inclination (24.1 k 5.1") at 90" flexion. At active maximum flexion (129.2 k 8.1°), the ligament was almost parallel (3.9 f 7.4" inclination) to the longitudinal axis of the tibia. At passive maximum flexion (1 58.8 f 5.8"), the inclination was reversed anteroposteriorly. measuring -23.0 k 6.7". The PCL and PT moved in a corresponding manner within 20" of discrepancy. The results of this in vivo study of the PCL have clinical relevance to conservative therapy for PCL knee injuries. The results of this study could also be useful in PCL reconstruction surgery to determine the optimum graft position to allow maximum postoperative motion.

Osteochondritis dissecans (OCD) of the lateral femoral condyle sometimes occurs with a discoid lateral meniscus. Recently, it was reported that OCD of the lateral femoral condyle occurred after total removal of the lateral meniscus. We report the case of a 12-year-old boy with bilateral OCD of the lateral femoral condyle following bilateral total removal for discoid lateral meniscus. Valgus deviation of the knee after total removal and increased sporting activity might have concentrated excessive stress on the lateral condyles in the standing position. As a result, bilateral OCD might have occurred. Drilling of the areas of OCD on the bilateral lateral femoral condyles was done and the patient wore inner wedge arch supports postoperatively. After 2 years, neither knee pain nor arthrosis has occurred so far, but long-term follow-up of this patient is considered to be necessary.

There was no significant difference in the incidence of post-operative femoral tunnel communication between two techniques. To avoid post-operative femoral tunnel bone communication, more than 2 mm distance of bone bridge at surgery is recommended.