[Case-control study on midterm follow-up effects of the extended release of posterior clearance in total knee arthroplasty].

OBJECTIVE: To evaluate the midterm follow-up results of extended release of posterior clearance in total knee arthroplasty. METHODS: A total of 120 patients with knee osteoarthritis were equally randomly assigned to the experimental group and control group, and underwent unilateral TKA from March 2010 to March 2012. In experimental group, there were 21 males and 39 females with an average age of (62.2±10.9) years old. In the control group, there were 25 males and 35 females with an average age of (64.9±11.4) years old. All the patients were performed using the anterior knee approach. During operation, after osteotomy of the tibia and the femoral condyle, extended release of the posterior knee clearance were taken in experimental group, while only the clearance of osteophyte in the posterior condyle were performed in the control group. The KSS scores including knee functional score and knee clinical score,as well as the range of motion (ROM) of patients, were compared between the two groups at midterm follow-up. RESULTS: Totally 49 patients in the experimental group and 54 patients in the control group were followed up, and the median follow-up time was 46 months. The knee functional score of patients in the experimental group was 91.3±3.4, which was better than 86.4±3.9 of patients in the control group; initiative ROM of flexion of patients in the experimental group was (133.2±5.9)°, which was better than (126.9±7.4)° of patients in the control group. There were no significant difference of knee clinical score between 86.9±4.6 of patients in the experimental group and 85.7±5.1 of patients in the control group, and the initiative ROM of extension between (0.5±1.1)° and (0.3±1.2)°. CONCLUSION: Extended release of the posterior knee clearance contributes to the knee function and initiative flexion ROM during a midterm follow-up and patients benefit.

[Effect of extended release of posterior clearance on flexion clearence and range of motion of the knee in total knee arthroplasty].

OBJECTIVE: To observe the change of clearance and range of joint improved situation during total knee arthroplasty (TKA) by operating extended release manipulation of the posterior knee clearance. METHODS: A total of 120 patients with knee osteoarthritis undergoing unilateral TKA from March 2010 to March 2012 were equally randomized prospectively assigned to the experimental group and control group, each 60 cases. There were 46 male and 74 female patients, the mean age was 63.6 years (range from 49 to 75 years). After the osteotomy of the tibia and the femoral condyle and before the release of soft tissue intraoperation, patients in experimental group were taken the extended release manipulation of the posterior knee clearence while the control group were cleaned the osteophyte of the posterior condyle only, 2-sided paired t test was used to compare the clearence intraoperation and the time to flexion angle of 90° and 120° and the maximum angle after 3 months' follow-up. RESULTS: There was no significant difference of the index between the experimental group and control group (P > 0.05). Between experimental group and control group, the difference was significant in extention clearance ((18.9 ± 1.5) mm vs. (17.9 ± 1.6) mm, t = 3.53, P < 0.01) intraoperation, and no significant difference in flexion clearance ((20.7 ± 1.8) mm vs. (20.2 ± 1.9) mm, t = 1.48, P > 0.05). It took longer time for the knee flexion range of motion to 90°(t = 10.2399, P < 0.01) or 120°(t = 11.142, P < 0.01) of the control group than that of the experimental group, and the difference of the maximum range of motion between experimental group and control group was significant statistically at the 3-months follow-up (t = 4.4255, P < 0.01). All the patients were followed up for 3 - 24 months, average of 14.6 months, no femoral component loosening happened. CONCLUSIONS: Extended release of the posterior knee clearance benefits the knee extension clearence intraoperation and functional exercise of range of motion postoperation, while it is no meaning to the flexion clearence.