Background Developmental factors were assumed to be the key factors that influenced the morphology of femoral trochlea. This study investigated the effects of insufficient patellar stress after birth on the morphological development of the femoral trochlea. Effects of insufficient patellar stress on femoral trochlea were investigated using surgical induced patellectomy and patellar dislocation in growing rat model. Methods In this study, two experimental groups and one sham group (SG) were established. Thirty-six Wistar rats (female, 28 days of age) were randomly assigned to three groups. The patellectomy group (PG), rats underwent the patellectomy in this group. The dislocation group (DG), rats underwent the surgery-induced patellar dislocation. Histological staining (Safranin-O and fast green), Micro-computed tomographic (Micro-CT) analysis in two experimental endpoints (3, 12 weeks postoperatively) were selected to evaluate morphological changes of the femoral trochlea. Results Articular cartilage on the trochlear sulcus was remodeled at 3 weeks after the surgery, and degenerated at 12 weeks through the histological staining. The femoral trochlear angle (FTA) did not show a significant difference at 3 week between the experimental groups and the sham group (PG vs SG P = 0.38, DG vs SG p = 0.05), but the FTA was significantly increased in experimental groups at 12 weeks(PG vs SG P = 0.001, DG vs SG p = 0.005). The Bone volume density (BV/TV), Trabecular number (Tb.N) under the trochlea groove were significantly reduced at 3 weeks postoperatively in the experimental groups (PG vs SG p = 0.001, DG vs SG p = 0.002). No significant difference was found in BV/TV and Tb. N among the three groups at 12 weeks postoperatively. Conclusion Surgical induced patellectomy and patellar dislocation leads to the dysplastic trochlear sulcus in growing rats. Besides the bone morphology of trochlear sulcus, the articular cartilage and subchondral trabecula under the trochlear sulcus were remodeled early stage after the surgery.

IV.

No abstract

No abstract

This article compares the long-term outcomes of closing-wedge osteotomy (CWO) and opening-wedge osteotomy (OWO) in the treatment of unicompartmental medial osteoarthritis with varus deformity. This study included 79 patients who underwent high tibial osteotomy (HTO) between 2002 and 2008. Pre- and postoperative radiography and computed tomography were used to evaluate the posterior tibial slope, the patellar height, the tibiofemoral angle, and the lateral and medial tibiofemoral joint space. Pre- and postoperative severity of arthritis was assessed with the Kellgren-Lawrence grading system. Pre- and postoperative American Knee Society (AKS) score and Lysholm Knee Score (LKS) were determined to evaluate functional outcomes. The duration of follow-up was 86.1 ± 6.2 months. Postoperatively, at the most recent follow-up, there was a slight increase in the size of the medial tibiofemoral joint space after CWO and OWO, which reflected a decrease in stress on the medial compartment and manifested as a significant improvement in the AKS knee and function scores and the LKS. OWO increased the posterior tibial slope as compared with the preoperative value, while CWO reduced the posterior tibial slope. CWO and OWO for HTO resulted in similar functional outcomes. OWO was associated with patella infera and more severe patellofemoral arthritis, while CWO was associated with a greater severity of lateral tibiofemoral arthritis.