Restoring the level of the knee joint line during revision arthroplasty: randomized controlled trial

The spatial orientation of the endoprosthesis components and the level of the joint line are the conditions for the success of revision knee arthroplasty. The OBJECTIVE was to test the proposed tool for precision restoration of the level of the knee joint line along the top of the head of the fibula and to evaluate the effectiveness of the technique based on the results of revision arthroplasty. METHODS AND MATERIALS. A single center randomized controlled study was conducted at the Department of Traumatology, Orthopedics and Disaster Surgery of the Sechenov First Moscow State Medical University of the Ministry of Health of Russia (Sechenov University). Inclusion criteria: aseptic loosening and aging of the knee joint components. Two groups of patients: the first (main) group underwent revision TKA with determination of the level of the joint line according to the method proposed by us using the original instrument, the second (control) – revision arthroplasty according to the standard method. A total of 64 patients were included in the study: 26 men and 38 women, mean age – 66.5±7.2 years, BMI on average – 32.9±2.6 kg/m2, the average period of revision knee arthroplasty was 36.3±6.7 months. Before and after the operation, CT and X-ray in the frontal plane were performed, the height of the joint line was measured, focusing on the top of the head of the fibula; testing on the VAS pain scale, knee joint scales: OKS, FJS-12, KSS, SF-36 for 12 months after operation. RESULTS. According to CT data, the height of the joint line in the frontal plane before surgery: group I – 21.9±3.3 mm, group II – 23.4±2.1 mm (p=0.946), after surgery: group I – 23.7±3.4 mm, group II – 20.8±3.0 mm, p=0.584). When testing for VAS, OKS, FJS–12, KSS, SF–36 for 12 months, there was no statistically significant difference between the groups. CONCLUSION. The proposed method and instrument make it possible to position the level of the knee joint line more accurately (by 3.9 % according to CT data and by 6.4 % according to X-ray data) during revision arthroplasty.