[Summary] Gender difference study of meniscus injury shows certain clinical significance in understanding epidemiologic characteristics of meniscus injury .Several large amount case studies demonstrated that the risk of meniscus tears was significantly higher in male than in female .However , in certain kinds of sports and special types or locations of meniscus tears , especially in medial meniscus posterior root tear ( MMPRT ) , there were more females than males .Further large amount case studies were needed for a deeper understanding of meniscus tears .In this paper,we reviewed the current situation and progress of gender difference of menisus tear .

Objective To summarize the clinical effect of arthroscopic Pridie drilling technique for repairing full-thickness articular chondral defects of the knee.Methods A retrospective study was made on clinical data of 28 patients(29 knees) with full-thickness articular cartilage defects treated with arthroscopic Pridie drilling technique from November 1999 to July 2005 in this hospital.A Kirschner wire 1.0~1.2 mm in diameter was used in the procedure to puncture holes in the subchondral bone plate.Holes were made adjacent to each other as closely as possible,but not to break into neighbouring ones,with normally 2~3 mm apart.The depth of the hole was 3~4 mm.A protected weight-bearing protocol lasting 6~8 weeks and continous passive motion(CPM) were used postoperatively.The Tegner activity levels,the Meyers scores,and the Lysholm knee scores were used for evaluation before and after the operation.Results The surgical outcomes were classified as "excellent" in 19 cases,"good" in 5 cases,and "poor" in 4,with the total effective rate being 85.7%(24/28).The Tegner activity levels were elevated from 1.9?1.2 preoperatively to 4.9?1.9 postoperatively(t=10.912,P=0.001),the Meyers scores from 10.3?1.3 preoperatively to 15.9?2.6 postoperatively (t=10.101,P=0.005),and the Lysholm knee scores from 47.7?12.5 to 83.2?15.4(t=10.302,P=0.003),respectively.Conclusions Arthroscopic Pridie drilling is a simple,safe,mini-invasive,and effective technique, which appears to be a practical surgical option for the treatment of full-thickness articular chondral lesions of the knee.

Objective To study the type Ⅰ,Ⅱ,Ⅲ and Ⅹcollag e n expression in meniscus and articular cartilage and immunoreactions post xenoge nic and allogenic meniscus transplantation. Methods After men iscectomy,30 adult New Zealand white rabbits were divded into two groups:group A undertook allogenic medial meniscus transplantation and group B undertook xenog enic meniscus transplantation with fitted meniscus tissues harvested from swine. 6, 12 and 24 weeks post transplantation, the histological and immunohistochemical analysis of type Ⅰ ,Ⅱ,Ⅲ and Ⅹ collagens monoclonal antibody were investigated in menisci and a rticular cartilage. Peripheral blood were obtained for immunoreactions study thr o ugh the methods of CDMT (Complement Dependent Microlymphocytotoxicity Test) and RIA (Radioimmunoassay)of IL-2 and IL-6. Results The meniscu s and articular cartilage were good post allogenic meniscus transplantation, but the transplanted xenogenic meniscus appeared to be dissolved and absorbed and c art ilage lesions were observed in 24 week post operation. No significant difference was found between two groups in type Ⅰ,Ⅱ and Ⅲ collagen expression during e xperiment. From 1～12 weeks, no significant diffe rence was found among type Ⅰ,Ⅱ and Ⅲ collagen expression in articular cartil age in two groups. However,24 weeks post operation, type Ⅹ collagen's expressio n in cartilage was abnormally increased. Neither allogenic nor xenogenic meniscu s transplantation caused fatal immunoreaction during the whole experiment. Con clusion The transplantation meniscus began to be dissolved and absorbed after half a year, but allogenic meniscus transplantation achieved good results . Type Ⅰ,Ⅱ and Ⅲ collagen expression in transplanted meniscus and articular cartilage showed no difference between two groups, but the expression of type Ⅹ collagen was abnormally increased in xenogenic group 24 weeks post operation. No fatal immunoreaction was found in both groups.

Objective To study the magnetic resonance imaging (MRI) characteristic of bone bruises associated with acute anterior cruciate ligament (ACL) ruptures and to investigate the correlation between bone bruises and cartilage lesions. Methods The MRI findings of 37 cases of acute ACL ruptures associated with bone bruises were studied retrospestively. The classification and distribution of bone bruises were analyzed and the cartilage lesions were also observed under arthroscopy. Results A total of 57 independent bone bruises(type Ⅰ:14, type Ⅱ:32, type Ⅲ:3, type Ⅳ:6 and type Ⅴ:2) were documented by MRI in the 37 patients. 54 (94.7%) bone bruises located in lateral joint compartment with involvement of lateral femoral condyle in 31 and lateral tibial plateau in 23. Nine cases (15.8%) of articular cartilage lesions were found under arthroscopy in the area overlying bone bruises. Conclusion Bone bruises associated with acute ACL ruptures mainly located in the lateral compartment of knee, especially in anterior portion of lateral femoral condyle and posterior portion of lateral tibial plateau. Arthroscopic cartilage lesions were not corresponding to bone bruises.

BACKGROUND: Thawed allografts are usually discarded for various reasons. Whether these discarded allografts can be refrozen for later use and their histological changes in vivo have not been reported. OBJECTIVE: To investigate the histological characteristics of anterior cruciate ligament (ACL) reconstructed with the repetitive freeze-thawing allogenic Achilles tendon in New Zealand white rabbits. METHODS: Allogenic Achilles tendons were harvested from adult male New Zealand white rabbits, and were stored at -8 ℃ and thawed at 20 ℃ for 1, 2, 3 and 10 times, respectively, after sealed package and 60Co irradiation. Twenty-four adult male New Zealand white rabbits were enrolled: the left and right knees of 12 rabbits were respectively reconstructed with 1 (control group) and 2 times of freeze-thawing allogenic Achilles tendon, and another 12 rabbits underwent reconstruction with 3 and 10 times of freeze-thawing allogenic Achilles tendon, respectively. Three specimens from each group were evaluated with modified histology grading scores at 6, 12 and 24 weeks to assess the cell morphology, cell quantity, matrix staining intensity, fibrocartilage formation, new bone formation, tendon healing and cartilage injury. RESULTS AND CONCLUSION: The cell morphology, matrix staining intensity and total scores of the 10 times group were significantly higher than those of the other groups at 6 weeks (P < 0.05), but other parameters showed no significant differences among groups (P > 0.05). ACL reconstructed with 10 times of repetitive freeze-thawing allogenic Achilles tendons had higher histological scores at 6 weeks after modeling, but no significant differences were shown at 12 and 24 weeks after modeling. To conclude, our study only testifies better histological scores on the multiple times of freezethawing Achilles tendon than the less times of freeze-thawing Achilles tendon at the early period after operation.

In oder to make the bone tunnel in optimal position, effective and firm fixation, early functional recov- ery and minimally operative injury we reported a new technique in reconstructive anterior cruciate ligament(ACL)using patellar tendon autograft fixed with interference screw. With the assistance of arthroscopy 74 patients with ACL rupture were treated between October 1997 and April 1999. The clinical results showed that the operative injury was minimal, fixed bone grafts were accurate and the reconstructed ACL was isometricity. The reconstructed ligament could be fixed biologically and firmly because of used patellor tendon autograft with bone grafts at two end. Clinical experience of ar- throscopic - assisted ACL reconstruction was summarized.

Objective To study the prognosis of the implanted xenogenic and allogenic menisci, and the implanted menisci's protection effects on articular cartilage. Methods 30 adult New Zealand white rabbits were divided equally into two groups and the medial meniscus defection models were established by medial meniscectomy. Allogenic medial menisci implantation were done in group A. Small pieces of menisci tissue were taken from pig meniscus and moulded them as the same shape and size as rabbit's medial menisci,then, xenogenic menisci implantation were done in group B with these moulded grafts. 6, 12 and 24 weeks after the operations, rabbits were sacrificed to observe the implanted menisci and the articular cartilage on medial tibial plateau, medial femoral condylus and femoral trochlea with naked eye and histological method. Results After allogenic meniscus transplantation, the state of implanted meniscus was good, and healed well around the capsula. 24 weeks post allogenic meniscus transplantation, the injury of the articular cartilage was not in evidence. In short time post xenogenic meniscus transplantation, the state of meniscus and cartilage was good and after 24 weeks the xenogenic meniscus was dissolved and absorbed, the articular cartilage also showed degeneration and injury. Conclusion With xenogenic meniscus moulded from pig meniscus tissue,the implanted meniscus was resolved and absorbed and the cartilage degeneration also appeared after half a year. Post allogenic meniscus transplantation, the meniscus structure and function were reconstructed well and the articular cartilage was also well protected.

Objective To establish a ten-zone divisional method of the knee joint and investigate its clinical application to arthroscopic total synovectomy for rheumatoid arthritis (RA). Methods A total of 22 fresh frozen specimens of adult knee joints were prepared for anatomical study on the sagittal septum of the knee to establish ten-zone divisional method of the knee joint. A retrospective study was carried out on 37 patients with early-stage RA (40 knees) undergone arthroscopic total synovectomy. Among the cases,15 knees were operated according to ten-zone divisional method; and the other 25 were treated with the routine method. The patients were followed up for 10-72 months to evaluate their Lysholm score,Lequesne Index,and Larsen stage classification. Results There was a sagittal septum in the knees,connecting anteriorly to the fat pad,alar fold,or mucous ligament. The middle part of the sagittal septum lied between the anterior and posterior cruciate ligaments,and its posterior part formed the posterior septum of the knee. Considering the anatomy of the sagittal septum,the synovium of the knee could be divided into 10 zones. All of the patients underwent total synovectomy by ten-zone divisional method achieved excellent or good outcomes (100%,15/15),none of them recurred during follow-up. Among the 25 knees that received total synovectomy by routine arthroscopic method,17 achieved excellent or good outcomes (68%,17/25),and 8 had recurrence (Fisher's exact test,P=0.016). Conclusions Arthroscopic total synovectomy was one of the effective treatments for early-stage RA. The ten-zone divisional method for total synovectomy according to the structure of the knee sagittal septum could improve the clinical results of total synovectomy for rheumatoid arthritis.

Objective To evaluate the mid-term(44 months) outcomes of meniscus allograft transplantation in four patients.Methods Between June and July 2005,four patients(3 medial and 1 lateral;3 men and 1 women;aged 21,27,35,38 years) underwent arthroscopy-assisted meniscus allograft transplantation in our hospital.The clinical outcome of the patients was evaluated by assessing the symptoms and signs,IKDC,Lysholm,and Tegner scores and examining the anteroposterior and lateral radiographs of the transplanted knee,weight-bearing radiographs of the both knees,anteroposterior radiographs of the lower extremities as well as magnetic resonance imaging(MRI).One patient underwent second-look arthroscopy. Results The follow-up time was 44-45 months.During the period,all the patients showed a normal motion range of the knee without pain or effusion of the knee joints.The mean IKDC,Lysholm,and Tegner scores of the patients were 84.75?2.63,91.50?4.43 and 7.00?0.82 respectively,which were significantly higher than those detected before the operation(60.50?14.06,69.25?22.04 and 4.00?0.82).The radiological results revealed no obvious degeneration or alignment changes though a 2-mm narrowing was shown in one of the patients.MRI showed mild extrusion for the body of the transplanted medial menisci and Ⅱ to Ⅲ stage signal for the body and the posterior horn.Almost normal performance and tension of the transplanted meniscus was shown by arthroscopy. Conclusions Meniscus allograft transplantation shows good outcomes in mid-term follow-up.MRI is valuable for evaluating the implanted meniscus.

Objective To evaluate the diagnostic value of different sequences of magnetic resonance imaging (MRI) in repaired meniscus.Methods From September 2002 to December 2008,118 patients (130 menisci) underwent arthroscopic meniscus suture in our hospital,including 94 males and 24 females,aged from 15 to 50 years (average,25.7t7.5 years).All patients underwent MRI and second-look arthroscopy postoperatively.Different sequences of MRI were taken to evaluate the grade of meniscal signal at repaired site and the slices involved by grade 3 signal.The diagnostic sensitivity,specificity,accuracy,positive predict value (PPV) and negative predict value (NPV) were calculated for each sequence by using second-look arthroscopy as the gold standard.Results The total healing rate was 80.8％ (105/130) by second-look arthroscopy,which was higher than that by different sequences of MRI.The integrated T2 sequence held the highest diagnostic value,and the sensitivity,specificity,accuracy,PPV and NPV were 76.0％,71.4％,72.3％,38.8％ and 92.6％,respectively.According to the second-look arthroscopy result,the menisci were divided into the healed group and unhealed group.In the healed group,28.6％ of cases (30/105) showed grade 3 signal in MRI,which was less than that (76.0％) in the unhealed group.The rate of the new grade 3 signal (8.6％) and the slices involved by grade 3 signal (0.8±1.0) in the healed group were less than those (16.0％ and 3.0±2.0) in the unhealed group.Conclusion The diagnostic value of the integrated T2 sequence is encouraging with high sensitivity,specificity and accuracy.The new grade 3 signal in the repaired meniscus usually implies that the meniscus is not healed.