ObjectiveTo investigate the effects of meniscectomy and transplantation repair of 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. MethodsSeven 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 0° extension and 30, 60, 90, and 120° 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. ResultsThe 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). ConclusionThe 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.
ObjectiveTo investigate the diagnosis and effectiveness of limited operative treatment for multi-segmental lumbar disease. MethodsBetween February 2008 and February 2011, 47 patients with multi-segmental lumbar disease were treated, including 27 males and 20 females with an average age of 60.3 years (range, 38-82 years) and a median disease duration of 21 months (range, 6 months to 7 years). Based on preoperative clinical manifestation and imaging examination results, the possibility of preliminary responsible segment was identified as two levels in 31 cases (L4, 5 and L5, S1 in 22 cases, L3, 4 and L4, 5 in 6 cases, L2, 3 and L3, 4 in 3 cases) and three levels in 16 cases (L3, 4, L4, 5, and L5, S1 in 9 cases, L1, 2, L4, 5, and L5, S1 in 4 cases, L2, 3, L4, 5, and L5, S1 in 3 cases). Selective nerve root block (SNRB) was used in all cases to identify the responsible segment. Based on the results, the patients were treated by limited operative treatment. The operation time, intra operative blood loss, postoperative drainage volume, postoperative ambulation time, and complications were recorded. The clinical outcome was evaluated according to the visual analogue scale (VAS) scores for back and leg pain, Japanese orthopaedic association (JOA) scores, and Oswestry disability index (ODI). The position of internal fixators and interbody fusion were observed through lumbar anteroposterior and lateral X-ray films. ResultsThe responsible segment was identified as single level in 33 cases (L4, 5 in 18 cases, L5, S1 in 11 cases, and L3, 4 in 4 cases) and two levels in 10 cases (L4, 5 and L5, S1 in 6 cases, L3, 4 and L4, 5 in 3 cases, L2, 3 and L4, 5 in 1 case) by SNRB. After SNRB, 4 cases did not receive surgical treatment because of a low relief rate of less than 30%. The operations were performed successfully in all 43 patients. The mean operation time was 101.9 minutes; the mean intraoperative blood loss was 164.5 mL; the mean postoperative drainage volume was 238.9 mL; and the mean postoperative ambulation time was 38.2 hours. There was no complication of nerve injury or incision infection. All 43 patients were followed up 12-36 months (mean, 19.3 months). The VAS scores, JOA scores, and ODI after operation were significantly improved when compared with preoperative ones (P<0.05). The postoperative JOA recovery rates were 62.2%±12.6%, 63.4%±12.4%, and 68.6%±14.6% at 3, 6 months, and last follow-up respectively, showing no significant difference (F=2.841, P=0.062). The postoperative X-ray films showed that the internal fixators were in good position without loosening or fracture, and the interbody fusion was good. ConclusionAfter identifying the responsible segment by SNRB in the diagnosis, limited operative treatment is safe and reliable in the treatment of multi-segmental lumbar disease. It can relieve compression effectively, decrease the range of operation, maintain the spinal stabilization, and has a good effectiveness.