A simple radiographic predictor for rapid progression of hip arthrosis: the sacro-femoral-pubic angle in the coronal plane.

introductionThis study aimed to evaluate the association between coronal pelvic and sagittal spinal radiographic parameters and the rapid progression of hip arthrosis (RPHA). MATERIALS AND

methodsIn this retrospective case-control study, 92 patients (92 hips) who underwent hip arthroplasty were analysed. RPHA was defined as ≥ two millimeters of femoral head collapse or ≥ 50% narrowing of the hip joint space within 12 months. Patients were classified into two groups: the study group (n = 29) and the control group (n = 63), which comprised patients without RPHA during a minimum follow-up period of 12 months before the operation. Linear regression and receiver operating characteristic (ROC) curve analyses were performed to identify radiographic predictors of RPHA.

resultsRPHA was significantly associated with lumbar lordosis (p = 0.001), pelvic tilt (p = 0.012), sacro-femoral-pubic angle (SFP; p = 0.003), and T1 pelvic angle (p < 0.001). The predictive accuracy of SFP, based on the area under the ROC curve, was statistically comparable to that of established sagittal alignment parameters (p > 0.05). Patients with SFP < 62° had a significantly higher prevalence of RPHA than those with SFP ≥ 62° (p = 0.007).

conclusionsSFP, measurable from standard anteroposterior pelvic radiographs, may represent a simple and practical alternative to sagittal spinopelvic parameters for identifying radiographic features associated with RPHA.