[Effects of meniscectomy and transplantation of human knee on stress of tibiofemoral articular surface].

OBJECTIVE: To investigate the effects of meniscectomy and transplantation repair ot the knee on the stress area and average pressure of the tibiofemoral articular surface so as to provide a reference for the relevant basic and clinical researches. METHODS: Seven qualified right knee joints from adult men cadavers were selected. Required structure was retained after careful dissection. The pressure-sensitive paper was clipped to the proper size in accordance with the measured size of the tibial platform to reserve. The experiment was divided into 4 groups: normal knee group (group A), knee meniscus injury group (group B), knee meniscectomy group (group C), and knee meniscus transplantation group (group D). A horizontal incision above the meniscus was made in the position of knee joint capsule, and the pressure-sensitive paper was placed into the medial and lateral space of the knee joint, then the proximal tibia and distal femur were fixed stably and finally a universal mechanical machine was used for testing in appropriate environmental conditions (the knee joints were given longitudinal 700 N pressure at 00 extension and 30, 60, 90, and 1200 flexion for continuous 120 seconds) until the full color reaction. The knee models were prepared, and then the universal mechanical machine was used to perform a test according to the method stated above respectively. The pressure-sensitive paper was removed, and the color negative films were separated and marked. Colorful image analysis system was used to calculate and analyze the stress area and average pressure after the scanner being used to collect image information. RESULTS: The stress area was gradually reduced and the average pressure was gradually increased with increasing flexion angle of the knee. There was significant difference in the stress area and the average pressure between various flexion angles in 4 groups (P < 0.05). Group C had significantly lower stress area and significantly higher average pressure than the other 3 groups (P < 0.05), but no significant difference was found among groups A, B, and D (P > 0.05). CONCLUSION: The stress of the tibiofemoral articular surface significantly increases after knee meniscus injury or resection, and the average pressure significantly increases. The stress of the tibiofemoral articular surface can be restored to almost normal after meniscus transplantation. Therefore, the injured meniscus should also be retained or repaired in the static state.

Robust revascularization, despite impaired VEGF production, after meniscus allograft transplantation in rabbits.

BACKGROUND: Little is known about vascularization restoration and vascular circulation after allogenic graft transplantation, which are both important prerequisites for optimal use of allograft meniscus transplantation. PURPOSE: To study vascularization restoration through autograft and allograft meniscus models in Oryctolagus cuniculus. STUDY DESIGN: Controlled laboratory study. METHODS: Forty-eight rabbits at mature bone age were randomized to receive either an autograft or allograft after the meniscus of the left knee was completely resected. Vascularization, blood circulation, histological characteristics of the grafted meniscus and surrounding tissues, and vascular endothelial growth factor (VEGF) expression in the meniscus were assessed at 4, 8, and 12 weeks after allograft or autologous transplantation. RESULTS: The grafted meniscus was in good condition and was well connected to the surrounding joint capsule, and no obvious damage of the joint cartilage at the tibial plateau was observed. Even though the revascularization pattern was similar in the 2 groups, the meniscus body showed vessel growth mainly at the adhesion margin for less than one-third of the meniscus transverse diameter, and no significant vascular distribution was found at the free margin. Blood circulation peaked after 8 weeks at the anterior and posterior horns and declined thereafter. This was mimicked by VEGF expression, which showed a progressive decrease with time, even though the vascular endothelial cells gradually increased over time. There were no statistical differences in the various assessments between the allograft and autograft groups. CONCLUSION: At 12 weeks after meniscus allografting, the vascular circulation had almost recovered and gradual reconstruction of cells and fibers had begun, mimicking similar observations in the autograft group. CLINICAL RELEVANCE: Our data provide test reference for clinical rehabilitation after meniscus autograft.