[Translated article] Clinical and radiological study of the final outcome of Legg-Calvé-Perthes disease

The prediction of outcomes in Legg-Calvé-Perthes disease (LCPD) has traditionally relied on femoral head sphericity and hip joint congruence as determinants of the risk of osteoarthritis in adulthood. However, other less explored radiographic parameters may enhance the ability to anticipate functional prognosis. The aim of this study was to analyze the relationship between novel radiographic parameters of LCPD and patient-reported outcome measures (PROMs) in adulthood, including hip function, sports activity level, and quality of life.

A retrospective observational study was conducted in patients over 18 years of age with a history of LCPD in childhood. The latest available hip radiograph was assessed for sphericity and congruence (Stulberg classification), degree of osteoarthritis (Tönnis), femoral neck height (FNH), articulo-trochanteric distance (ATD), epiphyseal extrusion index (EEI), Sharp angle (SA), and neck-shaft angle (NSA). Patients completed the Hip Disability and Osteoarthritis Outcome Score (HOOS), Oxford Hip Score (OHS), modified Harris Hip Score (mHHS), UCLA Activity Level, and the 12-Item Short Form Survey (SF-12).

A total of 141 adults (154 hips) were included, with a mean age of 31.6 years (19-71) and a mean follow-up of 22.1 years (10-68). The distribution according to Stulberg classification was: class I (12%), II (18%), III (32.5%), IV (28%), and V (10.5%). Sixty percent of patients showed radiographic signs of osteoarthritis, with 34% being Tönnis grade 1. Multiple regression analysis identified femoral neck shortening (FNH), trochanteric overgrowth (reduced ATD), and femoral head extrusion (increased EEI) as predictors of poorer PROMs (p<.05). Regression equations were developed to estimate PROMs in adulthood based on these three parameters.

In addition to femoral head sphericity, joint congruence, and the degree of osteoarthritis, measurement of FNH, ATD, and EEI provides predictive value regarding functional outcomes, sports activity level, and quality of life in adults with a history of childhood LCPD.