PRE-OPERATIVE LOW BACK PAIN NEGATIVELY AFFECTS SELF-REPORTED FUNCTION IN INDIVIDUALS UNDERGOING HIP ARTHROSCOPY

Abstract

Background/purpose: Low back pain (LBP) is a common source of disability in adults and highly prevalent in patients with painful hip pathology. Persistent LBP after hip arthroplasty is associated with lower self-reported function, however, the effect of pre-operative LBP in patients undergoing hip arthroscopy for FAI has not been evaluated. The purpose of this study was to determine whether improvements in self-reported hip function following arthroscopic surgery for femoroacetabular impingement (FAI) differed between those with and without reports of pre-operative low back pain.

Study design: Cohort.

Methods: Three hundred eighteen subjects undergoing primary hip arthroscopy for clinically and radiographically-confirmed FAI were recruited and consented. One hundred fifty-six of these subjects completed the International Hip Outcomes Tool (iHOT-33) and the Hip Outcome Score Activities of Daily Living Subscale (HOS-ADL) before, and six and 12 months after surgery. Subjects were grouped based on the self-reported presence or absence of LBP prior to arthroscopy. A repeated measures analysis of variance was used to determine the effects of time and low back pain on iHOT-33 and HOS-ADL scores.

Results: Seventy-five of 156 subjects (48.1%) reported LBP prior to surgery. A main effect of time was found for both outcome measures (p<0.001), demonstrating improvement in self-reported outcomes over the testing period. There was a main effect of group for the iHOT-33 (LBP: 52.0 [47.9,56.0]; no LBP 57.9 [53.9,61.8]; p = 0.043) but not for the HOS-ADL (LBP: 75.2 [72.2,78.2]; no LBP 78.8 [75.9,81.7]; p = 0.088) indicating that subjects with pre-operative LBP had poorer self-reported function per the iHOT-33 compared to those without LBP.

Conclusion: Self-reported hip function scores improved regardless of the presence of pre-operative LBP; however subjects with LBP reported poorer self-reported function per the iHOT-33 as compared to those without LBP up to 12 months post-operatively.

Level of evidence: 3c.

Keywords: Femoroacetabular impingement; low back pain; outcomes.

Figure 1.

Subject Recruitment Process Subjects were recruited from the Hip Preservation Division at The Ohio State University Wexner Medical Center. Subjects who completed outcome measures at all time points were included in the data set and grouped by presence or absence of self‐reported pre‐operative LBP.

Figure 2.

iHOT‐33 scores in subjects with and without LBP iHOT‐33 scores in those with LBP (blue) and without LBP (red) at pre‐op, 6 months, and 12 months post‐op. 95% confidence intervals are shown.

Figure 3.

HOS‐ADL scores in subjects with and without LBP HOS‐ADL scores in those with LBP (blue) and without LBP (red) at pre‐op, 6 months and 12 months post‐op. 95% confidence intervals are shown.