Unicompartmental knee arthroplasty improves mental health in patients with single compartment knee osteoarthritis

The purpose of this study was to determine if preoperative mental health status improves following unicompartmental knee arthroplasty (UKA) in patients with single compartment knee osteoarthritis (OA).

A total of 163 patients underwent UKA [115 (71%) medial, 48 (29%) lateral] (mean age = 65 ± 11) completed preoperative and minimum 2-year postoperative veterans RAND 12 item health survey (VR-12) mental component score (MCS). VR-12 MCS was the primary outcome measure. Secondary measures included VR-12 physical component summary score (PCS), knee osteoarthritis outcome score (KOOS) and KOOS patient acceptable symptom state at the final follow-up.

The median VR-12 MCS improved from 50.5 [interquartile range (IQR): 43.7-56.8] to 55.0 [IQR: 52.3-57.0] (p < 0.001) at a mean follow-up of 9.5 ± 4 years (range 2-19 years) following UKA. Preoperative VR-12 MCS was significantly correlated with patients postoperative VR-12 PCS (ρ = 0.294, p < 0.01), KOOS pain (ρ = 0.201, p = 0.012), KOOS ADL (ρ = 0.243, p = 0.002) and KOOS quality of life (ρ = 0.233, p < 0.01). Sixty-three (39%) patients improved from low VR-12 MCS (<50) to normal VR-12 MCS (≥50). One hundred forty-two (87%) achieved a normal VR-12 MCS score (≥50) postoperatively.

At a mean of 10-year follow-up, patients who underwent UKA for single compartment osteoarthritic knee pain demonstrated significant improvement in mental health scores. UKA resulted in normal mental health in a majority of patients (87%). The resultant improved mental health scores were associated with improved patient pain and activities of daily living.

Level III retrospective cohort study.