[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.