[Repair full-thickness meniscal defects with injectable tissue engineering technique].

OBJECTIVE: To investigate the effectiveness of injectable tissue engineering to repair full-thickness meniscal defects. METHODS: From June 2008 to February 2009 full-thickness of meniscal defects were created in the anterior corner of goats, which with no blood supply, in a diameter of 2 mm. Then bone marrow stem cells (BMSCs) was mixed with injectable calcium alginate gel to fill the defects. Other groups include the calcium alginate gel and empty group were served as control groups. At different time points, the animals were sacrificed and macroscopy, microscopy determination, electroscopy and MRI detection were performed to assess the outcomes of repairing. RESULTS: The meniscal defects had been filled thoroughly in 16 weeks after operation with white, tough and elastic repair tissue similar to normal meniscal fibrocartilage in the tissue engineering groups. The repair tissue was mainly fibrochondrocytes in line with the calcium alginate fiber. Thick matrix secreted by the cells crammed the space between fibers. The view under electroscopy demonstrated that the microstructure of the repair tissue was normal and cells were in a fibrocartilage phenotype. CONCLUSION: The full-thickness meniscal defects in regions without blood supply can be reconstructed effectively with injectable tissue engineering.

[The efficacy of open-wedge high tibial osteotomy for varus knee].

OBJECTIVE: To introduce the biplanar opening high tibial osteotomy with rigid fixation for adult varus knee. METHODS: Twelve patients with varus knee and degeneration of medial compartment received the biplanar opening high tibial osteotomy between June 2001 and July 2008. The pre-operative deformity was about 11.5 degrees without osteoarthritis changes in other compartments. The average range of motion was more than 90 degrees . One of the patients had ruptures of LCL and ACL, who received osteotomy after reconstruction of the ligaments. The main symptom before the operation was pain in medial compartment. The range of motion, Lysholm score and subjective satisfactory examinations were assessed before and after the osteotomy. RESULTS: All of the osteotomy sites were healed at twelve to sixteen weeks after operation. No complications such as plate broken or injury of nerve or blood vessel had occurred. The mean correct angle was 9.5 degrees . No degenerative changes had developed in other compartments of the knee. The mechanical axis of the lower extremities was maintained during the follow-up. The overall satisfactory rate was 83.3%. Statistically significant changes exist in the Lysholm score and varus degree. CONCLUSION: The open-wedge high tibial osteotomy is suitable for the symptomatic genu varum in younger patients with good short-term and mid-term results.

Modified biplanar open-wedge high tibial osteotomy with rigid locking plate to treat varus knee.

OBJECTIVE: To introduce and characterize the modified biplanar opening high tibial osteotomy with rigid fixation to treat varus knee in young and active patients. METHODS: Between June 2001 to July 2008, 18 patients with monocompartmental degeneration of the knee combined with a varus malalignment of the leg had the modified biplanar opening high tibial osteotomy and the osteotomy was fixed with the locking plates (Locking Compression Plate System). The mean varus deformity before operation was 11.5 degrees (5 degrees approximately 19 degrees ) and no degenerative changes were found in other departments. Stability of the knee was normal in 15 patients, but ruptures in anterior cruciate ligaments or lateral collateral ligament were presented in the remaining 3 patients. Preoperative symptom was mainly limited in the pain of medial compartment. The preoperative and follow-up data for the range of motion and Lysholm score were determined. Subjective satisfactory examination was also applied to the patients for the operation they selected. RESULTS: All of the patients were followed up with an average of 32.5 months (12 approximately 82 months). There was no ununion or delayed union in this group during the follow-up period. No complications like broken plate, nerve injury, or blood vessel injury occurred. The postoperative average corrected degree was 9.5 degrees (5.5 degrees approximately18 degrees ). No degenerations developed in the three departments of the knee. The Lysholm scores before and after surgery were 42.5 and 77.5, respectively (P<0.01). The overall fineness rate was 83.3%. The subjective satisfactory survey demonstrated that about 83.3% patients showed satisfactory on the operation. There was no obvious difference in the range of motion before and after operation, but significant changes were found in the Lysholm score and varus degree from preoperative to follow-up. CONCLUSION: Proximal opening high tibial osteotomy performed in conjunction with the special rigid locking plate yielded good results for symptomatic genu varum. This new classic technique can be effectively applied to the medial compartment degeneration of the knee in active young patients.