BACKGROUND:Prosthesis friction interface is a hot focus in the study of total hip joint. Polyethylene wear particles induced inflammatory reaction, resulting in osteolysis surrounding the prosthesis and prosthesis loosening. To reduce polyethylene wear, ceramics-ceramics and ceramices-polyethylene friction interfaces were selected. High cross-linked polyethylene material with high intensity was selected. In young patients with large activity amount, the application of ceramic head is a great progress. OBJECTIVE:To assess the safety of large-diameter alumina ceramic matrix composites (BIOLOX? delta) bal on third-generation highly cross-linked polyethylene (Trident X3, Stryker, Mahwah, NJ) total hip arthroplasty in young patients, and to perform radiological measurements of high cross-linked polyethylene wear rate in the shortest two years after fol ow-up. METHODS:From July 2008 to June 2010, wear analysis of 30 cases aged less than 60 years with 32 hips with 36-mm BIOLOX ? delta ceramic femoral heads (CeramTec, Plochingen, Germany) on highly cross-linked polyethylene was performed in the 455 Hospital of Chinese PLA using Roman software (Robert Jones&Agnes Hunt Orthopaedic Hospital, Oswestry, United Kingdom). The mean age of patients was 56.8 ± 6.5 years. RESULTS AND CONCLUSION:Fol ow-up was conducted from 2 to 3.7 years old. There were no imaging evidences, such as dislocation, the bal head fracture or joint loosening or osteolysis. Mean Harris score was increased from (19.9±7.3) (11-36) before replacement to (35.3±5.4) at 6 months after replacement. The mean wear rate was (0.022±0.11) mm/year after run-in period. These data indicated that large-diameter ceramic head articulation against highly cross-linked polyethylene in young patients would have high safety for joint dislocation, prosthesis fragmentation and low wear rates.

[Objective]The patellar tendon lengths were compared in the knees with a history of patellar instability and in normal knees in Chinese,and the significance of patellar tendon length measurement in the knees of patellar instability was discussed.[Method]Totally 49 knees of 43 patients with patellar instability were reviewed from Jan.2003 to Dec.2005,including 15 males and 28 females and 6 paients with both instahle patellas.The mean age was 21.4 yrs(from 18~28 yrs),and the mean height was 163 cm(155~173 cm).And,50 normal control knees of 50 volunteers including 16 males and 34 females.The mean age was 24.2 yrs(from 18~35 yrs),and the mean height was 165cm(154~177 cm).The patellar tendon length,the distance between tibial tubercle and the anterior edge of tibial plateau and Insall-Salvati index on the lateral X-ray plain with 30? flexion of keens were measured and analyzed.[Result]The patellas tendon length of patients was longer than that of normal volunteers(53.3?2.7mm,47.3?3.3 mm,P0.05)of the distance from tibial tubercle to the anterior edge of tibial plateau between patients and volunteers.However,difference of Insall-Salvati index between patients and volunteers was significant(1.33?0.17,1.06?0.14,P

BACKGROUND:Signal transducer and activator of transcription 3 (STAT3) is an important cytokine signaling pathway, which plays an important role in inflammatory diseases. However, it is unclear whether gene polymorphism of STAT3 is associated with rheumatoid arthritis in the Chinese Han population. OBJECTIVE: To explore the association of gene polymorphism of STAT3 with rheumatoid arthritis in the Chinese Han population. METHODS:Four tag-single-nucleotide polymorphisms (tag-SNPs) in STAT3 were selected from the Chinese Han population of HapMap database. The study was performed with 228 rheumatoid arthritis cases and 228 normal controls. Four tag-SNPs (rs12601982, rs2293152, rs8078731 and rs9912773) were examined by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. RESULTS AND CONCLUSION:The frequency of GG genotype at rs9912773 was 18.9% and 10.5% respectively in rheumatoid arthritis and control groups, and there was a significant difference between the two groups (P < 0.05). These results indicate the possible association between the STAT3 gene polymorphism at rs9912773 and the susceptibility of rheumatoid arthritis in the Chinese Han population.

BACKGROUND:Differentiation of growth factor-induced cells into fibrocartilage is the hot topic in the research of meniscus tissue engineering. The in vitro construction and in vivo reconstruction of menisci are closely related with the effect of growth factors. OBJECTIVE:To review the current development of growth factors in meniscus tissue engineering, and to investigate the mechanism. METHODS:The VIP database (http://lib.cqvip.com), CNKI database (www.cnki.net) and PubMed database (http://www.ncbi.nlm.nih.gov/pubmed) were retrieved for the related articles from January 2008 to March 2013 with the key words of“meniscus tissue engineering, cartilage, growth factors”. A total of 53 articles on the research of growth factors in meniscus tissue engineering were included. RESULTS AND CONCLUSION:There were various growth factors in cartilage tissue engineering research, and the new growth factors have been found in the constant. The research on the regulation effect of growth factors on cartilage was changed from the research of single growth factor model to the research of the interactions between multiple growth factors;the molecular mechanisms of growth factors in regulating the cartilage have also been extensively studied. Growth factors have good application prospects in tissue engineering, but there are stil many problems to be solved, such as during the healing of menisci, the expressions and the effect of different growth factors are different in different time points. So how to play the interaction between growth factors timely and appropriately thus stimulating the in vivo microenvironment, investigating the molecular mechanisms of growth factors in regulating the cartilage, as wel as finding the new growth factors are the research focus in meniscus tissue engineering.

Objective To explore the differences of the joint function and the patient's satisfaction between two different methods to reconstruct limb length for unilateral Crowe Ⅳ developmental dysplasia of the hip (DDH).Methods The clinical controlled study were used.21 cases with unilateral DDH Crowe Ⅳ treated with total hip arthroplasty were divided into 2 groups randomly.The patients in the first group were reconstructed the limb with the compensatory length and those in the second group were did with the real length.The patients were followed up 10 years.Two independent sample t-test was used to compare these two operations.Harris scores and SF-36 scores were used in the test.Survival analysis with Kaplan-Meier method was involved in the survival of the prosthesis and then test with Log-rank test.X-ray films of different period were compared to confirm the prosthetic loosening.Results Seventeen patients were followed up 8-10 years.There were no significant differences both in Harris score and most of the SF-36 scores at the median follow-up of 10 years.The item mental healthy of SF-36 expressed significant difference.Five patients required revision.There were 10 cases suffered with polyethylene wear,6 cases with severe osteoporosis in greater trochanter,and 3 cases with osteolytic reaction.Conclusion There are no significant differences between the two surgical method in the survival rate of prosthesis and the joint function in the median follow up.The satisfaction of the control groups is lower than the trial groups both at the early stage after the operation and the median follow up.The revision rate between the two groups is similar but the reason is different.

BACKGROUND:A large amount of studies have confirmed that synovial mesenchymal stem cells have the similarity in cellmorphology, immune phenotype, colony forming ability and differentiation potential with bone marrow mesenchymal stem cells. But bone marrow mesenchymal stem cells are better than synovial mesenchymal stem cells in the ability to differentiate into cartilages. OBJECTIVE:To discuss the possibility of using synovial mesenchymal stem cells as seed cells for meniscal tissue engineering. METHODS:The synovial mesenchymal stem cells were isolated from rabbit synovial tissues with limiting dilution monoclonal culture method, and then the cells were purified. The morphology, ultrastructure, molecular phenotype, proliferation kinetics, karyotype and tumorigenicity of the in vitro cultured cells were analyzed. RESULTS AND CONCLUSION:The synovial mesenchymal stem cells isolated from the rabbit synovial cells had high proliferation capacity during in vitro monolayer culture. The synovial mesenchymal stem cells grew to peak at 6 days, and the doubling time was (30.2±2.4) hours. Flow cytometry results showed the synovial mesenchymal stem cells could express some molecular makers of mesenchymal stem cells, such as CD44 and CD90. DNA contents check, karyotype test and oncogenicity test confirmed isolated and purified synovial mesenchymal stem cells were the normal diploid cells without tumorigenicity, so the cells can be used as seed cells for meniscal tissue engineering.

BACKGROUND: Previous artificial ligament is easy to break for material fatigue and to appear synonitis for materialbiocompatibility.OBJECTIVE: To observe the application effect of ligament advanced reinforcement system (LARS) artificial ligament inreconstruction of anterior cruciate ligament via follow-up.DESIGN, TIME AND SETTING: An own control, follow-up observation was performed between August 2004 andJanuary 2007 at the Department of Orthopedics and Joint Surgery, Shanghai Changzheng Hospital, Shanghai, China.PARTICIPANTS: Twenty-eight patients with anterior cruciate ligament injury, including 16 with sport injury and 12 withvehicle accident injury.MATERIALS: The main component of LARS artificial ligament (Laboratoire d'Applieation et de Recherche Scientifique,France) is the high-tenacity polyester fiber polyethylene terephthalate.METHODS: Twenty-eight patients with anterior cruciate ligament injury were performed arthroscopic reconstruction of theligament with LARS artificial ligament and were averagely followed up for 20 months.MAIN OUTCOME MEASURES: Patients' anterior drawer test, Lysholm score, range of motion prior to transplantationand in follow-up.RESULTS: The knee unstable symptom of 28 patients disappeared, anterior drawer test was negative, joint function wasgood with the flexion of 5.71 to 129.64 degrees. Average Lysholm score raised from (45.7±9.82) points prior totransplantation to (86.5±6.44) points after transplantation (P < 0.001). All patients resumed normal activities at 2 monthsafter transplantation, without acute or chronic synovitis and host response to materials.CONCLUSION: LARS artificial ligament is a relatively safe transplantation material and especially suitable to reconstructanterior cruciate ligament with sport injury. Mid-/short-term follow-up shows good result.

BACKGROUND:Some overseas searchers have shown that,the midvastus approach in total knee arthroplasty(TKA)can reserve the complete medial structure of quadriceps femoris,improve the functional recovery of knee extension apparatus,but also preserve the blood supply of medial knee joint and maintain proprioceptive sense of knee joint.OBJECTIVE:To evaluate the early functional outcome of midvastus approach and standard medial parapatellar approach in TKA.DESIGN:A prospective,randomized,double-blind,comparative study.SETTING:Changzheng Hospital Affiliated to the Second Military Medical University of Chinese PLA.PARTICIPANTS:From March 2004 to March 2006,34 patients undergoing bilateral TKA simultaneOusly were admitted to the Changzheng Hospital Affiliated to the Second Military Medical University of Chinese PLA,including 7 males and 27 females.They aged 56-78 years with a mean of 70.5 years,and consisted of 24 cases with osteoarthritis,and 10 cases with rheumatoid arthritis;24 cases with bilateral genu varum,9 cases with bilateral enu valgum,and 1 case with lateral genu varum and contralateral genu valgum.Informed consents were obtained from all the included patients.Materials:Press Fit Condylar(PFC)Sigma knee prosthesis(DUPUY Company),the central tibial pad was added with a polyethylene prominence,while the corresponding femoral prosthesis was treated with anterioposterior steotomy,identical with the remained prosthesis.METHODS:The surgical approach of 34 patients was randomized into a midvastus approach in one knee and a standard medial parapatellar approach in the other knee.The comparison included the surgical parameters and clinical parameters.mevemnt,the time of performing an active straight leg raise,the time of reaching 90°knee flexion,range of motion and complications.RESULTS:All of 34 patients were involved in the result analysis.There was no significant difference in the surgical time botween the two roups.The assessment revealed significantly less blood loss[(286±29.8)Ml,(368±35.8)Ml,P＜0.05],fewer lateral release in valgus knee(20%,50%,P＜0.05),less pain in the first week(P＜0.05),earlier return of active straight-leg raise[(1.8±0.3)days,(4.5±0.8)days,P＜0.01],earlier reach of 90° knee flexion [(3.2±0.8)days.(7.1±1.2)days,P＜0.01]and greater range of motion at 45 day[(107±20)°,(98±12)°,P＜.05]in the midvastus approach group.CONCLUSION:The midvastus approach,which is based on diminished disruption of extensor mechanism and peripatellar pIexus of vessels,relieves pain and improves range of motion in the early rehabilitation period following TKA.

BACKGROUND:Smal intestinal submucosa is characterized as antimicrobial activity, good biocompatibility, bio-mechanical properties, and rapid degradation in vivo, similar to the extracellular matrix of meniscal
fibrochondrocytes.
OBJECTIVE:To observe whether there exists a good histocompatibility between smal intestinal submucosa and synovial mesenchymal stem cells.
METHODS:Smal intestinal submucosa was treated with physical and chemical treatment. And hematoxylin-eosin staining and scanning electron microscopy observation were performed. Then, smal intestinal submucosa extracts were prepared for the fol owing experiments. (1) Pyrogenic test:smal intestinal submucosa extracts were injected into the ear vein of New Zealand white rabbits. (2) Skin sensitization test:smal intestinal submucosa extracts, paraformaldehyde solution and normal saline were respectively injected intradermal y into New Zealand white rabbits. (3) General toxicity test:smal intestinal submucosa extracts and normal saline were respectively injected into the ear vein of New Zealand white rabbits. Smal intestinal submucosa was co-cultured with osteogenic rabbit synovial mesenchymal stem cells, and smal intestinal submucosa cultured alone served as control. RESULTS AND CONCLUSION:There were some intestinal mucosal epithelial cells, fat cells and other cells adhered onto the surface of smal intestinal submucosa after physical treatment. While, the amount of residual cells decreased sharply after chemical treatment. But the main structure and the component had not been changed. The surface of smal intestinal submucosa was smooth and no cells remained, and there was a three-dimension network spatial structure. The porosity was 80%. Smal intestinal submucosa is a non-toxic, nonirritating, non-immunogenic biomaterial with very good biocompatibility, which has a good histocompatibility with rabbit synovial mesenchymal stem cells.

Objective To assess the clinical significance of modular femoral component in restoring femoral offset after total hip arthroplasty.Methods Data of 75 patients,who had undergone THA with modular femoral component from June 2009 to June 2012,were retrospectively analyzed.There were 42 males and 33 females,aged from 44 to 83 years (average,64.7±12 years).There were 40 cases of left hip and 35 cases of right hip.The average Harris hip score was 54±6 (range,32 to 65) before operation.The Zimmer M/L Taper hip prosthesis with Kinectiv technology was used in all patients.Preoperative templating was utilized to accurately predict the prosthetic size and the femoral offset.During the surgery,the femoral offset was measured accurately,and the appropriate femoral neck prosthesis was selected in order to restore the femoral offset and reconstruct hip abductor moment arm.The femoral offset and leg length were measured according to X-rays after operation.The Harris hip score was used to assess the clinical results.Results The femoral offset was reconstructed in all patients,ranging from-3.0 to 3.0 mm (average,1.3±0.3 mm).The average leg length discrepancy was improved to 3.0±0.8 mm.All patients were followed up for 6 to 36 months (average,19.7 months).The average hip abduction angle was 40°±10° at 12 weeks after operation.The average Harris hip score was 86±13 (range,65-94) at 12 weeks after operation and 95±15 (range,78 to 98) at final follow-up.There was no hip dislocation and femoral acetabular impingement syndrome.Conclusion Modular femoral component can restore femoral offset without changing the leg length,which can result in good hip abductor strength,range of motion of the hip and stability,as well as less complications.