BACKGROUND:It has become increasingly concerned by the industry to detailed understand the morphology of people’s knee joint, thus achieving personalized and gender differentiated total knee arthroplasty, in order to design the knee joint prosthesis that match the characteristics of Chinese people. OBJECTIVE:To measure and characterize the morphological parameters of distal femur of normal adult Chinese people by CT tomography and three-dimensional reconstruction, and to discuss the differences between male and female in morphology of distal femur. METHODS:Seventy normal Chinese adults (35 males and 35 females, aging from 21 to 60 years) received bilateral knee joint CT scan. The scanning images of distal femur which we needed were col ected and handled with three-dimensional reconstruction or Picasa 3.0 software for col ages and overlapping exposure. The posterior condylar angle, anterior condylar angle and trochlear angle were measured on the images that treated by the software, as wel as the transverse diameter of distal femur, lateral condylar height, and the ratio between them. RESULTS AND CONCLUSION:The mean posterior condylar angle of Chinese women was larger than that of Chinese men (P<0.05);the mean anterior condylar angle of Chinese men was larger than that of Chinese women (P<0.05);The transverse diameter of distal femur, lateral condylar height and the femoral surface ratio (diameter/epicondyle height) of Chinese men were larger than those of Chinese women (P<0.05). The results showed that differences exist in morphology of distal femur between Chinese and western people. Also, the differences exist between male and female in Chinese people. These differences should be concerned in the design of femoral prosthesis for Chinese people as wel as in selecting and placing of femoral prosthesis before or during the total knee arthroplasty.

Objective To evaluate the effect of arthroscopic reshaping procedures on symptomatic discoid meniscus and compare the outcomes between children and adults. Methods The medical records of those who had undergone arthroscopic reshaping procedures for symptomatic discoid meniscus between January 1997 to December 2000 were reviewed. Results Fifty-four patients had been followed up more than 7 years, including 38 children and 16 adults. The average Lysholm score increased from (65.0?10.0) preoperatively to (72.0?10.0) postoperatively. The average 8.2-year follow-up showed no obvious clinical symptoms and signs or osteoarthritis in children. Fourteen knees in adults were found osteoarthritis on X-ray film, of which 6 showed the symptoms and signs of osteoarthritis. Conclusion The midterm efficacy of arthroscopic surgery for symptomatic discoid menisci and the occurrence of postoperative osteoarthritis are related to age and injury course.

Objective To introduce and evaluate arthroscopic release technique for treatment of knee stiffness due to arthrofibrosis after total knee arthroplasty (TKA). Methods Five patients with mean age of 56 years (41－ 70 years) underwent knee arthroscopy for a history of arthrofibrosis following TKA. There was no painful stiff total knee or infected total knee in this series. All of 5 cases had good range of motion in the operation room after total knee replaced. The arthroscopy was performed at 6 months (3－ 12 months) after the TKA, and at this time the flexion was limited to 70 degrees (60－ 85 degrees).In 2 cases,the extension was limited to 10 degrees and 30 degrees. With 3 standard portals, we examined the knee joint and found the adhesions and fibrous band formed in the suprapatellar pouch and two gutters. By resection of those fibro- band and passive flexion of the knee, the satisfactory range of motion(ROM)could be achieved. For the 2 cases of extension limited, CR prothesis was replaced. We released the posterior cruciate ligaments through the anterior portals. Continuous passive motion was started immediately postoperatively at the first day. The patients were evaluated at an average time of 20 months (8－ 46 months) after the arthroscopy. Results The mean knee ROM was 116 degrees (100－ 130 degrees) at the end of arthroscopy and was 105 degrees (90－ 115 degrees)at the last review.The mean ROM was improved by 35 degrees (15－ 50 degrees). There were no complications in this series. Conclusion Arthroscopic release for the treatment of knee stiffness due to arthrofibrosis without pain and infection following TKA is a useful, reliable and safe technique, compared with closed or open procedure. The arthrolysis should be done at 3 to 6 months after the TKA in order to obtain better results.

Objective: To determine the overlapping area of the femoral condyle facet on which the patellofemoral and tibiofemoral joint surfaces move and to measure the pressures on such area in order to better design the length of femoral trochlea prosthesis in patellofemoral arthroplasty. Methods: Eight fresh cadaver knees were mounted on Instron 8501 biomechanics tester,and simulated physiologically weight-bearing situation of knee from standing to flexion position. Such overlapping area was drawed up with stain method and the contact pressures were measured with Fuji pressure film. Results: There existed an overlapping contact area on the femoral condyle facet within the patellofemoral contact area when knee flexion was 75? or larger. The tibiofemoral contact pressure was higher than the patellofemoral pressure in the area. Conclusion: The femoral trocher prosthesis should cover the whole contact area of patellofemoral joint.

[Objective]To measure the verus inclination of the proximal tibial of young Chinese through radiographs and determine how many degrees should the femoral prothesis be externally rotationed during total knee arthroplasty(TKA).[Method]Standardized anteroposterior radiographs of the entire lower legs of 200 volunteers' were taken. Two angles were measured as followes:Angle PT: angle between tibial articular margins and a line perpendicular to the tibial mechanical axis;Angle FT:angle between the transcondylar tangent anda line perpendicular to the tibial mechanical axis. [Result]Angle PT has a mean value of 4.06? and Angle FT is 5.00?. [Conclusion]When the posterior condylar axis is used during TKA for Chinese, the femoral prothesis should be externally rotationed 5.00? to get the optimum rotational orientation.

0.05). Conclusion Compared with the Whiteside′s line, the transepicondylar axis seems to be more reliable to determine the rotational alignment of femoral component in total knee arthroplasty. The posterior femoral condylar angle of the Chinese people is larger than that of the Caucasians. If the widely used way of 3? lateral rotational orientation of the femoral component referring to the posterior condylar surfaces of the femur in total knee arthroplasty is adopted, it tends to produce internal malrotation of the femoral prosthesis after operation.

[Objective]To evaluate the incidence and predictors of stiff knees after primary TKA.[Method]A retrospective review was given to the data from 1216 patients undergoing primary total knee arthroplasty between October 1996 and October 2006.Forty-five stiff TKA patients with a 1-year postoperative flexion range of less than 90?was taken as treatment group.Forty-five TKA patients with greater than 90? flexion at 1 year postoperative as control group.The age,sex,body mass index,American Society of Anesthesiologists(ASA) rating,surgeon,implant type,and fixation of the control group were matched to those of the treatment group.A case-control study was conducted to determine predictive factors of stiff TKA.[Result]No significant differences were found with regard to the mean age,ratio of sex and preoperative medical comorbidities.Preoperative flexion and intraoperative flexion were predictive of ultimate postoperative flexion(P=0.001 and P=0.039,respectively).Preoperative and postoperative relatively decreased patellar heightwere significantly correlated with postoperative stiffness(P=0.001).[Conclusion]Stiffness post-TKA is multifactorial,careful attention to surgical exposure,restoring gap kinematics,minimizing surgical trauma to the patellar ligament/extensor mechanism,appropriate implant selection,and physiotherapy may all serve to reduce the incidence of post-TKA stiffness.

In this review,concepts concerning etiology and nonoperative and operative treatment methods have been analyzed.This article is based almost exclusively on peer-reviewed studies.The etiology of nontraumatic osteonecrosis of the femoral head may have genetic basis.The interaction between certain risk factors and a genetic predisposition may determine whether this disease will develop in a particular individual.Early diagnosis and intervention prior to collapse of the femoral head is key to a successful outcome of joint-preserving procedures.The rational for use of joint-sparing procedure in the treatment of this disease is based on radiographic measurements and findings with other imaging modalities.The results of joint-preserving procedures are less satisfactory than the results of total hip arthroplasty for femoral head than have already collapsed.New pharmacological measures as well as the use of growth and differentiation factors for the prevention and treatment of this disease may eventually alter our treatment approach,but it is necessary to await results of clinical research with long-term follow-up of these patients.

Objective This is a feasibility study of rabbit meniscus regeneration evaluated with the use of autologous bone marrow derived mesenchymal stem cells(MSCs) and collagen glycosaminoglycan(GAG). Methods Autologous MSCs were prepared from the rabbit proximal tibial bone marrow and stimulated in vitro to start fibrocartilage differentiation lineage by bFGF and TGF ? 1. Then, collagen GAG templates enriched with these MSCs were implanted in vivo to the menisci excised rabbit knees as the substitute for the excised meniscus. After 3, 6, 12, 24 weeks postoperatively, the implants were evaluated by the gross, histological and ultrastructural observations. Results The MSCs enriched collagen GAG implants underwent inflammation, degradation, MSCs division and remodeling stages in vivo, and consequently formed a meniscus like fibrocartilage tissue. Special staining and electronic microscope observation proved that the regenerated fibrocartilage were chondrocyte like fibrochondrocytes; in contrast, the results of the control group showed that both collagen GAG implants without MSCs and no substitute had limited regenerating tissue, further evaluations by histological and electronic microscope showed no evidence of fibrochondrocytes, and hence these regenerated tissue were fibrous rather than fibrocartilaginous. Conclusion The inducing of rabbit meniscus regeneration by the autologous bone marrow derived MSCs and porous collagen GAG template is proved to be feasible in this study. However, further studies to improve the biomaterial design, to evaluate the biomechanical properties of the regenerated tissue and to ensure clinical safety etc are needed prior to its clinical application.

AIM: To evaluate the analgesic effects of combining application of low-dose morphine and diprospan in intra-articular injection after knee arthroscopy.METHODS: ① A total of 100 patients with knee arthroscopy were selected from the Surgery of Joint, Department of Orthopaedics, Changzheng Hospital, the Second Military Medical University of Chinese PLA from February 2002 to January 2003, including 52 males and 48 females aged from 16 to 56 years. All of them did not have a history of administration of pain-killer before operation. Patients were classified from grade Ⅰ to grade Ⅱ based on American Society of Anesthesiologists (ASA) before operation. Meanwhile, all the patients did not have obvious histories of heart,lung and liver diseases, and all patients provided informed consent. ② All patients were randomly divided into two groups, including combination group and morphine group with 50 in each group. Patients in the combination group were given intra-articular injection with 1 mg morphine hydrochloride and 1 mL compound diprospan [Xianling Baoya Pharmaceutical Factory, Belgian; batch number: 4JBBKA35A; qualification: 1 mL (5 mg/2 mg)/ampoule] after operation.In addition, patients in morphine group were injected with 1 mg morphine hydrochloride [the First Pharmaceutical Factory, Shenyang; batch number: 020316; qualification: 1 mL (10 mg)/ampoule]. ③ At 8 and 24 hours after administration, when patients maintained the status of standing with both feet and unfolding knee joint, analgesic effect was evaluated by visual analogue scale (VAS). Scores ranged from 0 to 10. The higher the scores were, the severer the painfulness was. Moreover, various side effects were observed at 48 hours after operation. ④ Differences of data were compared with one-way analysis of variance and deep differences between the two groups were compared with q test.RESULTS: A total of 100 patients received knee arthroscopy were involved in the final analysis. ① Visual analogue scale: At 8 hours after administration, scores were similar in combination group to those in morphine group, and the scores were 1.41 ±0.74 and 1.52±0.65, respectively (q =2.72, P ＞ 0.05). At 24 hours after administration, scores were remarkably lower in combination group than those in morphine group, and the scores were 1.46±0.61 and 2.53±1.24,respectively (q =3.42, P ＜ 0.05). ② Adverse events and side effects: Side effects, which were always found out in the application of morphine in vein, were not observed in both combination group and morphine group.CONCLUSION: Combining application of low-dose morphine and compound diprospan has an excellent analgesic effect with intra-articular injection, which is superior to that of the single application of morphine. Meanwhile, the combining application of low-dose morphine and compound diprospan is safe.