The outcomes of non-surgically managed Perthes’ disease

Perthes' disease (PD) is an uncommon childhood condition. Few recent studies have reported the outcomes following non-surgical management of children with PD. This retrospective cohort study investigated the radiological development of an aspherical femoral head and the risk of requiring salvage surgery in these children. An analysis of risk factors was undertaken using age, sex, the Herring classification, and bilaterality as independent variables, with outcomes described using odds ratios (ORs). The median follow-up was 10.05 years (IQR 7.60 to 12.42). A total of 94 children with 105 hips were identified. PD presented at a median age of 6.17 years (IQR 4.31 to 7.87) and predominantly affected males. Bilateral disease was present in 11 children (11.70%). Non-surgical management resulted in the development of an aspherical femoral head in 62 hips (59.05%) at the end of treatment, and 12 (11.43%) required salvage surgery. The odds of developing an aspherical femoral head were significantly greater with increasing age (OR 1.81; p < 0.001) and in those with Herring group C hips (OR 8.78; p = 0.035), but significantly lower in males (OR 0.20; p = 0.018). For every year's increase in age at the time of diagnosis, the odds of requiring surgery increased by 57% (p = 0.003). Although the adjusted ORs were not statistically significant, of the patients in whom the diagnosis was made after the median age of six years, 11 (52.38%) of Herring group B hips and six (100%) of Herring group B/C hips developed an aspherical femoral head. These findings confirm that non-surgical management should be advised in children in whom the diagnosis of PD is made before the age of six years. However, the prognosis for those in whom the diagnosis is made after this age, with a Herring group B and above, was poor when compared with the findings reported in other studies. Further research should investigate the role of early containment surgery versus early primary total hip arthroplasty in patients with late-onset PD.