Intraoperative transillumination of the lateral parapatellar area during lateral release in total knee arthroplasty can preserve blood supply in patella: a pilot study

Abstract

Abstract Background. Intraoperative patellofemoral maltracking/instability is often corrected by lateral retinaculum release. Due to the fact, that the medial parapatellar approach dissects medial genicular arteries, forced lateral release can also cause excision of lateral vessels, which leads to total devascularization of the patella and obviously devastating patellar complications. In this study, we evaluated the possibility of precise intraoperative localization of the lateral genicular arteries (aa. superior et inferior genicularis lateralis) by an orthopaedic surgeon using the transillumination method. Methods. 12 patients underwent cemented TKA with patella-friendly Zimmer Biomet NexGen Legacy Posterior Stabilized prostheses (without patellar resurfacing), 7 right knees and 5 left knees. The mean age of patients in the study group was 66.636 ± 7.003 years. The minimal follow-up period was 13 months (mean – 16,363 ± 2,5 months). Functional outcomes were assessed using Knee Society and a specific patellar questionnaire - Kujala Score. Intraoperative detection of insufficient patellar stability and/or patellar maltracking was based on the no-thumb technique. In pre- and postoperative period X-ray investigation, standard standing X-ray and Merchant view were used to evaluate implant position and patellofemoral congruency. Results. In this study, ten out of twelve knee joints (83.3%) had at least one artery visible by the proposed method in the lateral parapatellar area. Five out of ten knee joints had more than one artery that could be visualized and identified as an arterial vessel. In postoperative Doppler ultrasound sonography, we found at least 1 artery, namely the superior lateral genicular artery in all 12 patients, 8 out of 12 patients had also an inferior genicular artery. Postoperative Knee Society score showed significant improvement from a mean 51.181 ± 3,868 to a mean 88,727 ± 3,663. Mean hospital length of stay is 8.545 ± 1.863 days. X-ray assessment using standard anteroposterior, lateral and Merchant skyline views showed appropriate implant positioning and patellofemoral congruency. The mean Kujala score in the postoperative period (3 and 6 months) was 67.3 ± 6.75 and 75.6 ± 6.42 perspectively. Conclusions. Using the proposed transillumination method can help preserve the lateral blood supply to the patella and to avoid devascularized patella-related complications Trial registration: This study was retrospectively approved by the Republican Ethical Committee. Trial registration number 3/3-1757 on 5 of May 2023.