The Relationship between Pre-Operative Pain Characteristics and Periacetabular Osteotomy Outcomes in Patients with Acetabular Dysplasia

INTRODUCTION: Bernese Periacetabular Osteotomy (PAO) is widely performed for patients with acetabular dysplasia, however the relationship between preoperative pain characteristics and patient-reported outcome measures (PROM) is not well-studied. AIMS: (1) Does maximum severity of pain in a location other than the groin that is greater or equal to that of the groin affect PROM? (2) Does the presence of nongroin pain affect PROM? (3) Does the severity of pain affect PROM? (4) Does the number of pain locations affect PROM? METHODS: We reviewed 52 hips (48 patients) treated with PAO for acetabular dysplasia from February 2017 to July 2020, using modified Harris Hip Score (mHHS), Hip Outcome Score (HOS), and international Hip Outcome Tool (iHOT-12) score, radiographic analysis, and pain location/severity questionnaires. Descriptive statistics, Analysis of Covariance (ANCOVA), and Spearman partial correlation coefficients were implemented. RESULTS: Twenty-six hips experienced the most severe pre-operative pain in the groin, and 26 hips experienced equal or greater pain in a non-groin location. Outcome scores between these groups were not significantly different (mHHS P = .59, HOS P = .48, iHOT-12 P = .99). Additionally, the presence of pre-operative pain in any non-groin location had no significant relationship with PROM (all Pvalues ≥ .14). Furthermore, the maximum severity of pre-operative pain and number of pain locations showed no significant relationship with PROM (maximum severity: mHHS P = .82, HOS P = .99, iHOT-12 P = .36; number of pain locations: mHHS P = .56, HOS P = 0.10, iHOT-12 P = 0.62). DISCUSSION: Location of most severe pre-operative pain and the presence of nongroin pain in a patient with acetabular dysplasia does not adversely affect PROM. Additionally, increased pain severity and pain locations does not appear to have any significant impact on outcomes. Therefore, a wide array of patients with acetabular dysplasia might expect similar, favorable outcomes from PAO regardless of pre-operative pain characteristics. CLINICAL RELEVANCE: This study attempts to fill a current gap in knowledge that could help orthopaedic surgeons better understand the relationship between pain location and hip outcomes for patients following PAO.