Comparison of early curative effects of lateral unicompartmental knee arthroplasty with total knee arthroplasty and the legacy constrained condylar knee arthroplasty in the treatment of isolated lateral osteoarthritis: a single-center retrospective study

Background Aims of this study were to compare the functional and radiographic results, perioperative complication after lateral unicompartmental knee arthroplasty (LUKA) with total knee arthroplasty (TKA) and the legacy constrained condylar knee (LCCK) arthroplasty for the treatment of lateral compartmental knee osteoarthritis (LCKOA), and to provide a basis for the treatment of LCKOA. Methods From January 2021 to January 2024, analyzed retrospectively clinical data of 74 patients with LCKOA treated with LUKA, TKA and LCCK arthroplasty. According to the operation plan, the patients were divided into three groups: LUKA group (23 cases), TKA group (23 cases) and LCCK group (28 cases). The changes of hip-knee-ankle (HKA) angle of the affected knee before and after operation were measured. All patients were assessed using the operation time, blood loss during operation, incision length, visual analogue scale (VAS) score before operation and after operation, Hospital for Special Surgery score (HSS), Oxford Knee Score (OKS), range of motion (ROM). Results All 74 patients were followed up for (2.38 +/- 0.33) years. The operation time, blood loss during operation, incision length and VAS score after operation in the LUKA group were significantly less than those in the TKA group and LCCK group (P < 0.05); HKA valgus angle, ROM, HSS score and OKS score of the three groups after operation were significantly better than those before operation (P < 0.05); There was no significant difference among the three groups in HSS score and OKS score (P > 0.05). Conclusion LUKA, TKA and LCCK arthroplasty have good clinical effect in the treatment of LCKOA; Compared with TKA and LCCK arthroplasty, LUKA has the advantages of less trauma, less bleeding, less pain and quick recovery. The short-term effect is satisfactory, and the long-term effect remains to be observed.