The Efficacy and Outcome of a Two-Staged Operation for Irreducible Knee Dislocation: A Prospective Short-Term Follow-Up

Background: Irreducible knee dislocation (IKD) is a very rare but serious type of knee dislocation; it can lead to soft tissue necrosis due to incarceration of the medial structures and faces great difficulty in the postoperative rehabilitation, too. IKD needs careful pre-operative planning. There is no universal agreement about the appropriate surgical strategy for IKD. The purpose of this study was to investigate the clinical efficacy, safety, and outcome of the two-staged operation in treatment of IKD.Methods: IKD patients were included from June 1, 2016 to May 31, 2020. In the stage-1 surgery, acute reduction and extra-articular structure repair were performed. Following an intermediate rehabilitation, delayed cruciate ligament reconstructions were performed in stage-2. Physical examination, CT, MRI, and X-ray were performed during the pre-operative period. Knee function, joint stability, ligament laxity, knee range of motion (ROM), and alignment were accessed at follow-ups. The minimum and maximum follow-up times were 0.5 years and 1 year, respectively.Results: In total, 17 IKD patients were included. There were three subjects (17.65%) missing at the 1 year follow-up and the average follow-up was 11.18 +/- 2.53 months. After stage-1, normal alignment and superior valgus/varus stability were restored in most subjects; however, a notable anterior-posterior instability still existed in most patients. The intermediate rehabilitation processed smoothly (6.94 +/- 1.20 weeks), and all patients achieved knee ROM of 0-120 degrees finally. At 0.5 years and 1 year follow-up after stage-2, all subjects had achieved normal knee stability, ROM, and satisfying joint function. No infection or DVT was observed.Conclusions: The two-staged operation for IKD has superior efficacy on knee stability and function, and it can facilitate the rehabilitation and achieve satisfactory short-term outcome.