Abstract: Objective To evaluate the early and mid-term clinical results of medial parapatellar soft tissue overlapping suture in total knee arthroplasty for treatment of severe osteoarthritis combined with permanent patellar dislocation. Methods We retrospectively analyzed the data of 12 patients (12 knees) diagnosed with severe knee osteoarthritis combined with permanent patellar dislocation undergoing total knee arthroplasty with medial parapatellar soft tissue overlapping suture. Knee Society Score (KSS), University of California Los Angeles (UCLA) activity-level rating, Visual Analog Scale (VAS) pain score, and knee range of motion of the patients were assessed before and 2 years after the surgery. Anteroposterior and lateral radiographs of the knee joint, full-length standing radiographs of the lower limbs and patellar axial radiographs were evaluated. Results The mean Knee Society Score of the patients increased from 34.2±11.1 before surgery to 73.5±6.3 at two years after the surgery (P<0.001). The UCLA activity-level rating increased from an average of 3.8 ± 0.8 before surgery to 5.8 ± 0.6 at two years postoperatively (P=0.003). The mean VAS pain score decreased from 42.8±6.0 before surgery to 20.1±3.7 (P<0.001) and the range of motion of the knee joint increased from 74.6±8.9 degrees to 97.5±4.5 degrees at two years (P<0.001). The radiographs showed no signs of subluxation or dislocation of the patella in all the patients. Conclusions Medial parapatellar soft tissue overlapping suture in total knee arthroplasty can achieve good early and mid-term clinical results for treatment of severe osteoarthritis combined with permanent patellar dislocation.

Key words: total knee arthroplasty; overlapping suture; osteoarthritis; permanent patellar dislocation