Objective To analyze the composition of hospital cost for total knee replacement (TKR)in recent years in order to improve the effectiveness of TKR,reduce its complications and extend the TKR more widely in China.Methods The data was obtained for primary unilateral TKA performed in2001,1998,1995compared with that performed in1992in Peking University People's Hospital.There were no postoperative complications and other surgical treatments during the hospitalization period.Results From1992through2001,prosthetic and physical therapy cost were predominantly increased214.2%and318.0%respectively in1998;219.8%and291.4%respectively in2001.The least cost was hospital room and blood transfusion fee.Among all the hospital costs in these four individual years,the most expensive was at-tributed to prosthesis cost,reached as54.7%,56.1%,56.0%and63.3%of total costs respectively.The influ-enced factors of the increasing hospital costs for TKR were as following:1)The using of imported knee im-plants increased in achieving better post-operative function of knee;2)The expensive imported antibiotic was widely used because of high drug-resistance due to the abuse of antibiotics;3)The anti-coagulative drugs on account of reducing the incidence of post-operative DVT was widely accepted;4)The emphasis on physical therapy was more considered.The possible factors of the decreasing hospital costs for TKR were using less expensive home-made antibiotics in short time just to prevent infections,reducing the length of hospital stay by enough preparation before operation,improving surgical technique and adopting preoperative blood salvage and re-transfusion to reduce the blood transfusion cost.Conclusion Through the analysis of total hospi tal cost of TKR in recent ten years,the prosthesis cost accounted for the most proportion,and the in crease of the hospital cost was attributed to prosthesis,anti-coagulative drugs,antibiotics and physical ther-apy.At same time,the average postoperative ROM of knee increased from93.6?to112.3?,and the in ci-dence of compli cations decreased from10.3%to5.3%.The better result of TKR,satisfactory knee function and the life quality of patient were obtained.

0.05). The rate of perioperative complications was significantly higher in the obese patients (P

Osteoarthritis is mainly caused by the degenerative changes of cartilage and cartilage extracellular matrix,while Aggrecanases degradate Proteoglycans which are the major components of cartilage.This review includes three aspects:(1) We have concluded the major enzymes(ADAMTS-4 and ADAMTS-5) which regulate the metabolism of cartilage extracellular matrix.Meanwhile,we have summarized the structure of aggrecanases(ADAMTS-4 and ADAMTS-5) and introduced the function of each regional structure;(2) We have concluded the way cytokines and glycosaminoglycans regulate the metabolism of aggrecanases,and discussed the regulation and control principle of cytokines and glycosaminoglycan;(3) We have summarized the majority of inhibitors to the aggrecanases,introduced the endogenic inhibitors,and put our emphasis on the extrinsic inhibitors(chelating agents,polypeptides and so on).Through deeper research on the enzymes,it will help us further understand the pathogenesis of osteoarthritis,and open up new avenues to clinical treatment.Abstract:SUMM ARY Osteoarthritis is mainly caused by the degenerative changes of cartilage and cartilage extra-cellular matrix,while Aggrecanases degradate Proteoglycanswhich are the major components of cartilage.This review includes three aspects:(1) W e have concluded the major enzymes(ADAMTS-4 and ADAMTS-5) which regulate the metabolism of cartilage extracellular matrix.Meanwhile,we have sum-marized the structure of aggrecanases(ADAMTS-4 and ADAMTS-5) and introduced the function of each regional structure;(2) W e have concluded the way cytokines and glycosam inoglycans regulate the metab-olism of aggrecanases,and d iscussed the regulation and control principle of cytokines and glycosam inogly-can;(3) W e have summarized the majority of inhibitors to the aggrecanases,introduced the endogenic inhibitors,and put our emphasis on the extrinsic inhibitors(chelating agents,polypeptides and so on).Through deeper research on the enzymes,it will help us further understand the pathogenesis of osteoar-thritis,and open up new avenues to clinical treatment.

BACKGROUND:There remains controversy that whether patel ar resurfacing in total knee arthroplasty and whether patel ar chondromalacia has influence on clinical outcomes.
OBJECTIVE:To evaluate anterior knee pain, clinical function and effects of patel ar chondromalacia on clinical outcomes after total knee arthroplasty without patel ar resurfacing for degenerative osteoarthritis.
METHODS:Clinical data of 162 patients (162 knees) with degenerative osteoarthritis undergoing total knee arthroplasty without patel ar resurfacing from June 2008 to February 2010 were retrospectively analyzed. Outerbridge classification was used for patel ar chondromalacia, Visual Analogue Scale for anterior knee pain, and the Knee Society clinical scoring system for clinical function.
RESULTS AND CONCLUSION:The incision of al patients reached stage-I healing. The patel ar chondromalacia:grade I in 18 patients, grade II in 36 patients, grade III in 62 patients, and grade IV in 35 patients. At the final fol ow-up, there were six (4.0%) patients with anterior knee pain, including four cases of mild pain and two cases of moderate pain, no severe pain. The mean Knee Society clinical scoring system scores and patel ar score were obviously elevated. Outerbridge classification did not affect the incidence of anterior knee pain after replacement (χ2=0.42, P=0.94), the Knee Society clinical scoring system score (knee score:F=1.83, P=0.14;functional score:F=0.56, P=0.64) and partel ar score (F=0.78, P=0.51). These data suggested that total knee arthroplasty without patel ar resurfacing for degenerative osteoarthritis can obtain satisfactory clinical outcomes, and the patel ar chondromalacia may not affect the clinical outcomes.

Objective To explore the techniq ue and clinical result of total knee replacement in flex-ion ankylosed knee.Me thods From December1987to December2000,30TKRs in16patients were per formed by means of medial parapatellar approach,secondary osteotomy and soft tissue balance for knees with bony ankylosis in flexion position.At the same t ime,an appropriate technique was adopted to excise the patella-femoral joint while the femoral-tibial joint was ankylosed,so that the bone distribution an d the ori-entation of joint line were made appropriately to facilitate implan t prostheses.By measuring the range of mo-tion(ROM)and HSS score system ,the effects of this operative methods and the procedure of osteoto my were evaluated.In this group,there were12males and4females.The average age at s urgery was33.6years old(range,20to69years).All knees were fixed at a n average of 46.5?(range,15?to95?),with ROM of 0?.HSS scores w ere in average of 31.4points(16to47points).Of the16cases,14cases underwent bilat-eral TKRs,and2cases unilateral TKR.Results In the present series,the operative time lasted for 1.6hours(range,1.2to2.1h)ther e were3cases suffering from paralysis of unilateral common peroneal nerve for half a year,there was no other complication happened in this group.The mean f ollow-up was67.1months(range,1to14years),the average ROM of knee wa s72.5?(range,60?to100?),lack of full ex ten sion(ex-tension l ag)was7.8?(range,0?to15?).HSS of knee joint was average78.7p oints(range,71to89points),Comparing with the pre-operation,there was i mprovement of 47.3scores.Conclusion Al though it is more difficult to perf orm TKRS in bony ankylosed knee than in those without ankylosis,how ever,by using tech niques of medial parapatellar approach,secondary osteotomy,soft ti ssue balance and the appropriate way to ex cise patellar-femoral joint and fem ur-tibial joint which were naturally ankylosed,the ankylosed knee defor mi ti es could be corrected successfully,and TKR is also possible to improve the func tion of knee and life quali ty in these patients significantly.

Objective To determine whether LTB4 could indirectly stimulate human osteoclast differentiation in RA through increasing RANKL expression of RAFLs. Methods We utilize the coculture model of RAFLs and monocyte which were stimulated in the presence of 2.5 ng/ml M-CSF in the control group, 2.5 ng/ml M-CSF +10-8 mol/L LTB4 in the experimental group A, 2.5 ng/ml M-CSF+10-8 mol/L LTB4+100 ng/ml OPG in the experimental group B. After culture for 3 weeks, through TRAP staining we counted the number of multinucleated TRAP staining positive osteoclast-like cells stained with TRAP to evaluate the differentiation effect in each group. Results There was almost no osteoclast-like cell in the control group and the experimental group B. Whereas there were many osteoclast-like cells in the experimental group A. Conclusion LTB4 can indirectly stimulate human osteoclast differentiation in RA through increasing RANKL expression of RAFLs.

ObjectiveTo detect the expression level of programmed cell death (PDCD) 5 and tumor necrosis factor(TNF)-α in serum and joint fluid from rheumatoid arthritis (RA) and osteoarthritis (OA)patients,and analyze the correlation between PDCD5 and TNF-α in order to study the role of PDCD5 in the pathogenesis of RA.MethodsFiftypatients(including 26 RA,24 OA) between December 2009 and August 2010 were selected to this study.ELISA was used to detect the concentration of PDCD5 and TNF-α in the serum and joint fluid.Two-independent sample t-test and Pearson's correlation analysis were used for statistics.ResultsIn both serum and joint fluid,the concentration of PDCD5 from RA patients [(37±33) vs (37±26) pg/ml ] was significantly higher than that of OA patients [ ( 13± 14) vs ( 11 ±7 ) pg/ml ] (P＜0.05).The concentration of TNF-α in the serum from RA and OA patients did not differ significantly(P=0.122),but its concentration in joint fluid of RA patients was significantly higher than that of OA patients (P=0.037).In the serum,there was significant correlation between PDCD5 and TNF-α (r=-0.55,P=0.004; r=-0.51,P=0.012)in both RA and OA patients.The correlation between PDCD5 and TNF-α in joint fluid of RA patients was statistically significant(r=-0.49,P=0.012),but no correlation could be found in joint fluid between PDCD5and TNF-α of OA patients(r=-0.353,P=0.09).ConclusionThis study suggests that PDCD5 and TNF-αare important apoptosis-regulatory factors in RA,and play important roles in the occurrence and development of RA.

Deep venous thrombosis (DVT) is one of the most common complications after total joint replacement, which is also one of the most concerned problems for clinicians. Domestic research data shows that the incidence of DVT in patients without thrombotic prophylaxis after joint replacement surgery are 20.6%-40.0%. The occurrence mechanism of DVT is explained by the Virchow theory, that is blood stasis, the blood vessel wall damage and blood coagulation state. The diagnostic rate of DVT is not satisfactory. The diagnosis of symptomatic DVT depends mainly on clinical symptoms and auxiliary examination. The diagnosis of asymptomatic DVT is mainly based on the auxiliary examination. The prevention and treatment of DVT after artificial joint replacement is currently mainly concentrated in the aspects of new oral anticoagulant agents, drug prevention method, and time limit.
Anticoagulants ; therapeutic use ; Arthroplasty, Replacement ; adverse effects ; Blood Coagulation ; Humans ; Incidence ; Venous Thrombosis ; diagnosis ; therapy

Bearing dislocation is a special complication of mobile-bearing unicompartmental arthroplasty, caused by many factors, such as imbalance of the flexion and extension gap, malposition of components, impingement by the remaining osteophytes and cement, damage or delayed chronic laxity of medial collateral ligament, traumatic accident and habitual high knee flexion. It can be reduced by strictly controlling the operation indications before operation, osteotomy and implanting the prosthesis accurately while protecting the medial collateral ligament during operation, actively guiding the appropriate rehabilitation actions and activity intensity of patients after operation. Treatment should be individualized according to the causes and individual conditions of patients.

Bearing dislocation is a special complication of mobile-bearing unicompartmental arthroplasty, caused by many factors, such as imbalance of the flexion and extension gap, malposition of components, impingement by the remaining osteophytes and cement, damage or delayed chronic laxity of medial collateral ligament, traumatic accident and habitual high knee flexion. It can be reduced by strictly controlling the operation indications before operation, osteotomy and implanting the prosthesis accurately while protecting the medial collateral ligament during operation, actively guiding the appropriate rehabilitation actions and activity intensity of patients after operation. Treatment should be individualized according to the causes and individual conditions of patients.