Application And The Short Term-effect Of Rotating Platform Total Knee System In The Total Knee Arthroplasty

Objective To investigate the clinical effects of rotating-platform total knee arthroplasty (TKA).Methods147patients (174knees) were treated with TKA in Tianjin Hospital between June2006and June2009.A11patients had knee pain at different degree and experienced difficulty in walking preoperatively. The flexion and extension of the knee were limited significantly. Some knees had flexion deformity and varus or valgus deformity at different degree. All the patients received the total knee arthroplasty (TKA) for the first time using mobile bearing or fixed-bearing total knee system. All the TKA operations were performed by a same group of experienced operators. The operation was performed by midline incision and medial parapatella approaches, the patella was treated with denervation and reparation, and then prosthesis was performed without replacements of patella. The affected limb was drived up postoperatively. The patients began limb muscle tension exercise when they were conscious after anesthesia. Broad-spectrum antibiotics were used in preoperative to prevent infection. All patients were administrated with low molecular weight heparin subcutaneous to prevent deep venous thrombosis (DVT).Drainage tube was taken out24-48hours postoperatively and the patients began continuous passive motion(CPM),twice a day.The patient were directed for active limb exercise and foot Sole Pump were used routinely to prevent DVT. Oral drug were taken to prevent DVT after discharge to3weeks postoperative. The fixation of prosthesis was observed by X-ray, the knee score and knee function score were evaluated by KSS scoring, and the complications were observed. Reexamination were taken at1、3、6、12months postoperative and then at every year. All the data were processed statistically by SPSS11.5and the results have statistical significance when p<0.05.(58knees),aged52～79years,;46cases with left knee,33cases with right knees and7cases with both knees. All patients were followed up for an average period of33.61months (24～48months)Results The operation were performed successfully and the operation time was range from60to100minutes, average70minutes. Incisions of all the cases were healed, and there was no infection, DVT, facture, nerve or vascular injury. Pain and function of all the patients were obviously ameliorated after operation.79patients (93knee) received the total knee arthroplasty (TKA) using mobile bearing total knee system, mean aged64.23years. The cases were composed of53cases with osteoarthritis (OA), including18men and35women and26cases with rheumatoid arthritis (RA), including6men and20women, the average courses was10.98years, The average period of follow up was37.28months.68patients (81knee) received the total knee arthroplasty (TKA) using fixed-bearing total knee system, mean aged62.46years. The cases were composed of44cases with osteoarthritis (OA), including16men and28women and24cases with rheumatoid arthritis (RA), including8men and16women, the average courses was11.12years, The average period of follow up was36.37months. The overall follow-up rate was78.5%.In group A, the average Knee Society knee scores improved from37.79scores preoperatively to88.69points; the average Knee Society function scores improved from32.37scores preoperatively to79.76points, and the average total range of knee motion improved from72.42°preoperatively to103.33°postoperatively. In group B, the average Knee Society knee scores improved from35.84scores preoperatively to87.51points; the average Knee Society function scores improved from29.67scores preoperatively to76.91points, and the average range of knee motion improved from65.06°preoperatively to99.01°postoperatively. Statistical analyses respect that each evaluation index in the two groups has no significant difference preoperatively. The knee function and range of motion of all patients were significantly improved at the latest follow-up. The mobile bearing total knee system was more advantageous in the average range of knee motion, but there was no significant difference in overall effect’s-ray showed there was no prosthesis loosening or patella dislocation. Six of fifty-eight knees with OA and four of thirty-five knees with RA in A group had lucencies around the tibial prosthesis, and the same in the five of the forty-nine knees with OA and three of thirty-two knees with RA in B group, but the radiolucencies were less than2mm and were nonprogressive.Conclusions Total knee arthroplasty using rotating-platform and fixed-bearing total knee system can improve the function of knee reliability and effectively. The rotating-platform total knee system was more advantageous in the average range of knee motion, but there was no significant difference in overall effect. The short term effect of TKA by rotating-platform total knee system is definite, but the long term-effect needs further follow up studies.