Patients With a History of Lumbar Fusion Have a Greater Risk of Revision Arthroscopy and Conversion to Total Hip Arthroplasty After Primary Hip Arthroscopy.

Purpose: To characterize the risk of revision hip arthroscopy or conversion to total hip arthroplasty (THA) among patients with a history of lumbar fusion undergoing primary hip arthroscopy.

Methods: We used the Statewide Planning and Research Cooperative System, an administrative database including all ambulatory and inpatient surgery encounters in New York, to identify all patients who underwent hip arthroscopy for femoroacetabular impingement between 2010 and 2020. Patients with previous lumbar fusion were identified using Current Procedural Terminology and International Classification of Diseases, Ninth and Tenth Revision, coding definitions. Patients with and without previous fusion were matched in a 1:5 ratio according to age and comorbidity burden. The number of levels fused was defined in the following fashion: (1) no fusion, (2) 1-2 levels, or (3) ≥3 levels. Patients were followed for 2 years to evaluate the rate of revision hip arthroscopy or conversion to THA. Multivariable logistic regression models were used to measure the association between number of levels fused and revision hip arthroscopy or conversion to THA.

Results: Between 2010 and 2020, there were 23,277 patients who underwent primary hip arthroscopy in New York state. Of these, 348 (1.4%) had a previous lumbar fusion. After matching for age and comorbidities, the composite rate of revision hip arthroscopy or conversion to THA was greater in patients with previous lumbar fusion compared with patients without (16.5% vs 8.5%; P < .001). This risk increased with the number of levels fused (1-2 levels: 15.1%; adjusted odds ratio, 1.8; 95% confidence interval 1.3-2.6; vs ≥3 levels: 26.3%; adjusted odds ratio, 3.4; 95% confidence interval 1.7-7.0).

Conclusions: Patients with a history of lumbar fusion had significantly greater rates of revision hip arthroscopy and conversion to THA compared with patients without previous fusion. The risk of revision hip arthroscopy or conversion to THA was increased approximately 2-fold in patients with 1 to 2 levels fused and 3-fold in patients with 3 or more levels fused.

Level of evidence: Level III, prognostic retrospective matched comparative case series.