Hip Arthroscopy Patients With Lower Back Pain Show Delayed Clinical Improvement and Inferior Time-Dependent Survivorship: A Propensity Matched Study at Mid-Term Follow-Up.

PURPOSE: To evaluate patient-reported outcomes (PROs) and survivorship at mid-term follow-up after hip arthroscopy (HA) for femoroacetabular impingement syndrome (FAIS) in patients with and without preoperative lower back pain (LBP).

METHODS

Patients with self-endorsed preoperative LBP who underwent HA for FAIS with mid-term follow-up were identified and propensity matched 1:1 to patients without back pain by age, sex, and body mass index (BMI). PROs collected preoperatively and at postoperative years 1, 2, and 5 included Hip Outcome Score-Activities of Daily Living (HOS-ADL) and Hip Outcome Score-Sports Subscale (HOS-SS), 12-item International Hip Outcome Tool (iHOT-12), modified Harris Hip Score (mHHS), and Visual Analog Scale (VAS) for Pain. Achievement of minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were compared. Survivorship was compared with Kaplan-Meier analysis.

RESULTS

In total, 119 patients with LBP were matched to 119 patients without LBP. Group demographic factors were as follows: age (37.4 ± 11.9 vs 37.6 ± 12.6 years, P = .880), sex (64.4% vs 67.7% female, P = .796), and BMI (25.3 ± 5.1 vs 25.3 ± 5.4, P = .930). Average follow-up duration was 6.0 ± 1.9 years. LBP patients showed similar preoperative PROs, yet lower 1-year scores for all PROs (P ≤ .044). At final follow-up, similar PROs were shown between groups (P ≥ .196). LBP and non-LBP patients had similar MCID achievement for HOS-ADL (59.3% vs 63.1%, P = .640), HOS-SS (73.9% vs 70.8%, P = .710), mHHS (66.7% vs 73.4%, P = .544), iHOT-12 (85.1% vs 79.4%, P = .500), and VAS Pain (75.6% vs 69.9%, P = .490). Groups also had similar PASS achievement for HOS-ADL (63.5% vs 61.3%, P = .777), HOS-SS (57.0% vs 62.5%, P = .461), mHHS (81.9% vs 79.1%, P = .692), iHOT-12 (54.6% vs 61.2%, P = .570), and VAS Pain (51.0% vs 55.4%, P = .570). Additionally, achievement of MCID ≥ 1 PRO (P ≥ .490) and PASS ≥ 1 PRO (P ≥ .370) was similar across groups. Conversion to total hip arthroplasty occurred in 3.4% of hips with LBP and 0.8% of hips without LBP (P = .370). Back pain patients demonstrated inferior time-dependent survivorship compared with patients without back pain on Kaplan-Meier survival analysis (P = .023).

CONCLUSIONS

Patients undergoing primary hip arthroscopy for FAIS with LBP achieve comparable PROs and clinically significant outcomes to patients without back pain at mid-term, despite lower 1-year PRO scores. LBP patients show inferior reoperation-free time-dependent survivorship compared with those without LBP.

LEVEL OF EVIDENCE: Level III, retrospective comparative case series.