Effect of Spinal Fusion Surgery on Total Hip Arthroplasty Outcomes: A Matched Comparison Study

Studies regarding postoperative outcomes after primary total hip arthroplasty (THA) in patients who have comorbid factors tend to focus on medical diseases. However, there is a paucity of literature examining the effect of a patient's orthopedic surgical history on outcomes after THA. Significantly, there are currently no studies on the effect of spinal fusion surgery on THA outcomes.

A review of 82 consecutive patients who had prior spinal fusion surgery who underwent elective THA from January 1, 2006 to December 31, 2015, was conducted. A matching cohort of 82 patients was selected from the remaining THA patients to maintain a 1:1 ratio control group. This cohort of 82 patients was matched for age, gender, body mass index ±5, preoperative Oxford score ±10, total Short Form-36 score ±10, and total Western Ontario and McMaster Universities Arthritis Index (WOMAC) score ±50. Data on the same functional outcomes were prospectively collected at 6-month and 2-year follow-up for comparison.

Patients without spinal fusion had better outcome scores than patients with prior spinal fusion, specifically in their 6-month WOMAC scores (253.33-225.07; P = .046), their 2-year Short Form-36 total scores (79.71-69.21; P = .041), and their 2-year WOMAC scores (213.5-267.41; P = .054).

This study demonstrates that patients with prior spinal fusion had worse outcomes after THA than patients without prior spinal fusion. This has clinical significance in counseling patients with previous spinal fusion undergoing THA.