The relationship between pre-operative pain characteristics and periacetabular osteotomy outcomes in patients with acetabular dysplasia

The aims of this study were to determine if pre-operative pain characteristics (location of maximum severity of pain, presence of non-groin pain, maximum severity of pain and number of pain locations) affect patient-reported outcome measures in patients undergoing periacetabular osteotomy (PAO) for acetabular dysplasia. 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 and Spearman partial correlation coefficients were implemented. 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 = 0.59, HOS P = 0.48, iHOT-12 P = 0.99). Additionally, the presence of pre-operative pain in any non-groin location had no significant relationship with PROM (all P-values ≥0.14). Furthermore, the maximum severity of pre-operative pain and number of pain locations showed no significant relationship with PROM (maximum severity: mHHS P = 0.82, HOS P = 0.99, iHOT-12 P = 0.36; number of pain locations: mHHS P = 0.56, HOS P = 0.10, iHOT-12 P = 0.62). Varying pre-operative pain characteristics do not appear to have any significant impact on outcomes. Therefore, a wide array of patients with acetabular dysplasia might expect similar, favourable outcomes from PAO regardless of pre-operative pain characteristics.