Objective To determine the biomechanical properties of anterior cruciate ligament allograft reconstructing posterior cruciate ligament in rabbits. Methods Based on the study of anatomy and biomechanics of normal rabbit cruciate ligaments, anterior cruciate ligament allografts were employed to reconstruct the posterior cruciate ligament in rabbits. The sterilized fresh-frozen allograft of bone-anterior cruciate ligament-bone were prepared and reserved for more than 14 days under -80 ℃. Twenty-four skeletally matured New Zealand white rabbits underwent a posterior cruciate ligament reconstruction on one knee randomly, the opposite knee was served as the paired control. Rabbits were sacrificed at 6, 12, 26 and 52 weeks respectively. Evaluations of the reconstructions and contralateral controls included the geometric, structural and material properties and rupture site. Results The mean length of the grafts at 52 weeks was 101% of the control (P=0.90), the cross-sectional area was 142%; the maximum load at 52 weeks was 83% of the control, the maximum elongation was 72%, the stiffness was 92%; the maximum stress at 52 weeks was 58% of the control, the maximum strain was 72%, and the modulds was 65%; the rupture site was all at the body part of the graft. The geometric, structural and material properties of the graft were gradually similar to those of the normal posterior cruciate ligament with the elapse of the time. Conclusion The biomechanical properpies of graft with similar material properties to normal posterior cruciate ligament following posterior cruciate ligament reconstruction in rabbits was favourable. The similar material properties of graft to normal posterior cruciate ligament play the very important roles in the posterior cruciate ligament reconstruction.

Objective To report the diagnostic and therapeutic effects of arthroscopic surgery on elbow sports injuries. Methods Nineteen patients with elbow diseases were treated by arthroscopic methods from January 1996 to February 2000. The modified HSS elbow rating scale was used as criteria of the efficacy. All patients were followed up for 4.5 months to 4.5 years (an average 8.6 months). Results Among nineteen patients, eleven had an excellent results, seven good, one poor, and satisfactory rate was 94.7 percent. Ten patients were satisfied greatly with the results,eight patients satisfied, one unsatisfied, the satisfactory rate was up to 94.7 percent according to the responses of questionnaire from the patients. The time resuming daily was in a medium of 7 days, and that for sports was in an average of 2.5 months. All the 11 cases of athletes and actors(actresses) resumed their previous seats. Complications occurred in 3 earlier cases, one had radial nerve temporary paralysis, the other two had residue loose bodies. Conclusion Elbow arthroscopic treatment is a reliable method with the advantages of minor trauma, quicker recovery and less traumatic manipulation. Careful pre-operative examination, selection of a safer portal of entry, and standard manipulation are very important points for the attainment of better results and less complications.

Objective To study the reasons, patterns of the injury and methods of early reconstruction of the articular cartilage injuries associated with the rupture of anterior cruciate ligament(ACL). Methods The pathologic change, location, degree of articular cartilage lesion were observed in 64 old ACL ruptures and 23 fresh ones by arthroscopy. The relationship between the incidence， duration of the injury, degree of cartilage injury and ACL ruptures, the correlation between the cartilage injury of femoral condyles and meniscus injury were studied. Results The incidence of articular cartilage injury in old ACL rupture group(75％ ) was significantly higher than that in fresh group(26％ )(P

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 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 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.

Objective To observe the articular cartilage injuries complicated with the rupture of anterior cruciate ligament(ACL)in 21 athletes and 43 non-athletes,and investigate the cause and the pattern of cartilage of knee following the ACL rupture in those patients.Methods The pathologic change,location,degree of cartilage lesion were observed. The relationship between the incidence, occurrent time,degree of cartilage injury and ACL rupture,injured degree of cartilage and the course of ACL rupture were studied.Results The incidence of cartilage injury were 75% in all patients, 66.7% in athletes and 79%in non-athletes. Incidence of cartilage injury in non-athletes was significantly higher than that in athletes (P<0.01).Incidence of serious injury of cartilage in the course more than 1 year was significantly higher than that less than 1 year (P<0.01),but there were no statistical difference between the two groups.Conclusion The incidence of articular cartilage injury following ACL rupture were significantly raised in athletes and non-athletes. The longer the ACL ruptured, the more serious the cartilage injured. Results indicated that articular cartilage injuries in the ACL rupture knee were mainly caused by the instability of knee.

Objective To investigate the targeted capacity of ultrasound contrast agent with a galactosepoly-L-lysine ligand,and lay the foundation for targeted imaging in vivo and the treatment of liver cancer.Methods The small molecular targeted ligand was synthetized by a method of reductive amination,the targeted lipid microbubbles were performed by combining lipid microbubbles with the targeted ligand,the targeted effectiveness was observed by fluorescence microscopy.Results Galactose and poly-L-lysine were combined effectively after 24 h with the molar ratio 1:1 00,the average particle size of the targeted lipid microbubbles was 2 micron,the targeted combine of the HepG2 liver cancer cells with the targeted ultrasound contrast agent was observed by laser scanning confoeal microscope.Conclusions The targeted lipid miembubbles can target effectively to the HepG2 cells.

Objective To establish the animal model(rabbit) of shoulder instability for providing the experimental basis of related studies.Methods shoulder joints of 6 skeletally matured New Zealand white rabbits were measured with the anatomical characteristics and joint motion range in order to determine the operative approach,the similarities of skeletal structure,surrounding muscles,joint capsule and ligaments between rabbit and human were compared.Eighteen rabbits,weighing between 2.5 and 3kg were randomized into 2 groups(experimental group 12 and control 6).In experimental group,instability model was established by means of the operation procedure as follows:the glenohumeral joint of right shoulder was exposed by cutting the subscapularis tendon,then the anteroinferior labrum and surrounding capsular ligament were excised.For control group,sham operation was performed by only curing the skin and superficial tissue,the subscapularis tendon and glenoid structures was kept intact.The specimens of 6 rabbits were harvested 6 weeks after operation.The remaining rabbits of both experimental and control groups were killed 12 weeks post the operation for specimens processing.The motion range and instability were measured in all specimens.Results The gross anatomy of shoulder ioint in rabbit is similar to human.In experimental group,the stability is showed less than control,grade 2 anterior instability was found.The motion range was restricted in all directions,such as external and internal rotation,extension and abduction compared to control group.Conclusion Rabbit is suitable to establish animal model for shoulder instability and related iniuries,the animal model which was designed by this study could provide valuable information for the research of anterior shoulder instability.