Comparison of Postoperative Functional Outcomes Between Subvastus and Medial Parapatellar Approach in Total Knee Arthroplasty

This study aims to compare the effects of the medial parapatellar approach (MP) and the subvastus approach (SV) on postoperative clinical function in total knee arthroplasty (TKA). A total of 84 patients, who visit the Joint Surgery Department of Peking University Third Hospital and are diagnosed with end-stage knee osteoarthritis and require unilateral, primary total knee arthroplasty, will be recruited. The patients will be randomly assigned to two groups, with 42 patients in each group. TKA will be performed using the MP and SV approaches respectively. Postoperative data such as quadriceps muscle strength, the time of first unassisted straight leg raise (SLR), joint range of motion (ROM), KSS score, WOMAC score, SF-12 score, VAS score, and shear wave elastography (SWE) of the medial thigh muscle will be collected. The patients will be followed up for 2 years postoperatively to compare the short-term and long-term clinical functional outcomes of the two surgical approaches.

Inclusion Criteria: * Patients aged 50 to 80 who are diagnosed with end-stage knee osteoarthritis that require unilateral primary total knee arthroplasty; * Patients who are determined by clinical and laboratory tests to have no absolute surgical contraindications; * Patients with good compliance, willing and able to undergo follow-up observations as required and sign the informed consent form; Exclusion Criteria: * Patients with a history of surgery on the affected knee joint in the past; * Patients with neuromuscular diseases; * Patients scheduled for knee joint replacement revision surgery; * Patients with active knee joint infection or systemic infection; * Patients who receive primary joint replacement due to non-knee osteoarthritis, such as rheumatoid arthritis, tuberculous arthritis, traumatic arthritis, etc; * Patients with valgus or varus deformity of the knee joint greater than 15°; * Patients with knee flexion deformity greater than 15°; * Patients whose heart and lung functions are determined by clinical and laboratory tests to be unable to tolerate surgery; * Patients with mental disorders who are unable to cooperate with treatment; * Patients who is lactating or pregnant; * Patients who are unwilling to participate in this study and did not sign the informed consent form; * Patients with poor compliance and inability to cooperate in completing the follow-up observers at critical times; * For any reason, the researchers believe that the subject is unlikely to complete this study.