Patient-reported Physical and Mental Health Outcomes Following Lumbar Spinal Fusion versus Total Hip and Total Knee Replacement.

Background: Total hip and knee arthroplasty (THA/TKA) are reliable surgical procedures for alleviating pain and optimizing function. Spinal fusion has also been shown to be beneficial, however the comparative benefit of THA/TKA to lumbar spinal fusion is incompletely understood.

Methods: This study analyzed a single-center database of patients who underwent primary lumbar spinal fusion, elective primary TKA, or THA. Patient-reported outcome measures (PROMs) included Veterans-Rand (VR12) Physical and Mental Component Score (PCS/MCS) for TKA/THA and PROMIS (Patient-Reported Outcomes Measurement Information System) Global Mental and Physical Health (GPH/GMH) for spinal fusion.

Results: A total of 356 patients who underwent TKA, 290 who underwent THA, and 125 who underwent spinal fusion were included. Joint replacement patients were older, with higher body mass index in the TKA group. Spine patients had a lower improvement in physical health than the joint patients (TKA: 9.4 ± 11.2, THA: 15.2 ± 11.2, Spine: 6.2 ± 8.7, P < 0.001) and a lower proportion of patients reaching the minimal clinically important difference (MCID). Spine patients had higher GMH improvements compared with TKA patients (TKA: -1.1 ± 10.7, THA: 1.1 ± 11.9, Spine: 1.8 ± 8.4, P = 0.009) and the highest proportion of patients reaching the MCID.

Conclusions: Spinal fusion, total knee arthroplasty, and total hip arthroplasty all significantly improved PROMs at 1-year follow-up. At baseline, spinal fusion patients had better physical function scores and worse mental health scores compared with joint arthroplasty patients, while spinal fusion resulted in mean smaller gains in patient reported physical function and higher gains in patient reported mental health function compared with arthroplasty.