The Impact of Spino-Pelvic Alignment on Total Hip Arthroplasty Outcomes: A Critical Analysis of Current Evidence.

Abstract

In this review, we (1) evaluated the effect of adult spine deformity (ASD) and its surgical correction on patients who had a total hip arthroplasty (THA); (2) evaluated the outcomes of THA in patients who have had previous spinal fusion; and (3) we presented an algorithm on how to surgically address patients who simultaneously require THA and ASD correction. A comprehensive literature search was conducted. Our final analysis included 14 studies. Overall, there were 3 studies that reported on the impact of ASD on THA outcomes, 6 studies reported on the effect of ASD correction on THA outcomes, and 5 studies reported on the effect of spinal fusion on THA outcomes. Patients with concurrent ASD and THA are at increased risk of THA dislocations and revisions with studies reporting a compiled 2.9% dislocation rate in 1167 patients. Patients who underwent ASD correction demonstrated a post-operative reduction of acetabular anteversion (mean reduction range 4.96°-11.2°, P < .001) and tilt (mean -7° ± 10°, P < .001). In THA patients with concurrent lumbosacral fusion, dislocation rates ranged between 3% at 1 year and 7.5% at 2 years compared to 0.4%-2.1% dislocation rates in matching cohorts (P < .001). Spine balance can alter THA outcomes, but the exact mechanism is yet to be elucidated. We aimed at bridging the gap between hip and spine surgeons with an up-to-date analysis of the best available evidence and presented an algorithm for approaching patients who may simultaneously need ASD correction and THA.