Title : Patient-specific versus oxford microplasty instrumentation in unicompartmental knee arthroplasty
Abstract:
Background: The purpose of the study was to compare patient-specific instrumentation (PSI) with Oxford microplasty instrumentation (MPI) in unicompartmental knee arthroplasty (UKA) for patients with anteromedial osteoarthritis (AMOA).
Methods: We performed a prospective study at a single high-volume orthopaedic hospital. All patients were randomly assigned to undergo either PSI-assisted UKA performed by inexperienced surgeons (PSI group) or MPI-assisted UKA performed by experienced surgeons (MPI group) at a 1:1 ratio. Radiological measurements included the femoral component varus and valgus angle, flexion and extension angle, tibial component varus and valgus angle, tibial posterior slope angle, and hip-knee-ankle angle (HKAA). The Knee Society Score (KSS) and Hospital for Special Surgery (HSS) score were assessed at one, three, six, and 12 months. Mixed-effects modelling was used to analyze repeated measurements.
Results: A total of 68 participants (34 in each group) were enrolled from June 2021 to July 2024. No patients were lost to follow-up. No significant differences between groups were found in the femoral component varus and valgus angle, flexion and extension angle, tibial component varus and valgus angle, tibial posterior slope angle, or hip-knee-ankle angle (all P >0.05). At the 12-month follow-up, the PSI group and MPI group achieved mean KSSs of 93.4 points (95% CI, 88.3-97.6) and 93.9 points (95% CI, 89.6-98.3), respectively. There were no significant between-group differences in the KSS and HSS score improvements from baseline to each follow-up point.
Conclusion: PSI-assisted UKA performed by inexperienced surgeons can yield radiological and functional outcomes comparable to those of MPI-assisted UKA performed by experienced surgeons in the treatment of AMOA. PSI is emerging as a promising alternative for practitioners inexperienced at UKA on a learning curve.
