Parkinson's disease (PD) adversely affects physical function after joint replacement. The biomechanical advantages of unicompartmental knee arthroplasty (UKA) may be particularly beneficial for these patients who suffer from gait and kinetic abnormalities. We aimed to describe the functional outcomes, complications and survivorship after UKA in patients with PD.
Ten patients (11 knees) undergoing primary fixed-bearing UKA for medial osteoarthritis were studied. Knee Society Knee (KSKS) and Function Scores (KSFS), as well as the Short-Form-36 (SF-36) Mental (MCS) and Physical Component Scores (PCS) were assessed preoperatively, at six months and at two years postoperatively. Complications, survivorship and all-cause mortality were analyzed.
No perioperative complications occurred. Length of stay was 5 ± 2 days and no patients were discharged to rehabilitation or readmitted. Nine of 11 knees had a flexion contracture preoperatively and this remained unchanged at two years. KSKS and SF-36 PCS improved significantly. However, there was no improvement in KSFS or SF-36 MCS. All patients achieved minimal clinically important difference for KSKS, six of 11 for KSFS and nine of 11 for SF-36 PCS. At mean 10 ± 5 years, there was one revision for progression of osteoarthritis. Seven of 10 patients progressed in Hoehn and Yahr stage and only three were able to ambulate independently at last follow-up.
Patients suffering from osteoarthritis and PD can experience a substantial improvement in knee pain with low morbidity after UKA. However, the improved kinematics of UKA did not translate to an improved range of motion or knee function postoperatively.