Prognostic factors and outcome of treatment in Perthes’ disease

Abstract

This nationwide prospective study was designed to determine prognostic factors and evaluate the outcome of different treatments of Perthes' disease. A total of 28 hospitals in Norway were instructed to report all new cases of Perthes' disease over a period of five years and 425 patients were reported and followed for five years. Of these, 368 with unilateral disease were included in the present study. The hips were classified radiologically according to a modified two-group Catterall classification and the lateral pillar classification. A total of 358 patients (97%) attended the five-year follow-up, when a modified three-group Stulberg classification was used as a radiological outcome measure. For patients over six years of age at diagnosis and with more than 50% necrosis of the femoral head (152 patients), the surgeons at the different hospitals had chosen one of three methods of treatment: physiotherapy (55 patients), the Scottish Rite abduction orthosis (26), and proximal femoral varus osteotomy (71). Of these hips, 146 (96%) were available for the five-year follow-up. The strongest predictor of outcome was femoral head involvement of more or less than 50% (odds ratio (OR) = 7.76, 95% confidence interval (CI) 2.82 to 21.37), followed by age at diagnosis (OR = 0.98, 95% CI 0.92 to 0.99) and the lateral pillar classification (OR = 0.62, 95% CI 0.40 to 0.98). In children over six years at diagnosis with more than 50% of femoral head necrosis, proximal femoral varus osteotomy gave a significantly better outcome than orthosis (p = 0.001) or physiotherapy (p = 0.001). There was no significant difference between the physiotherapy and orthosis groups (p = 0.36), and we found no difference in outcome after any of the treatments in children under six years (p = 0.73). We recommend proximal femoral varus osteotomy in children aged six years and over at the time of diagnosis with hips having more than 50% femoral head necrosis. The abduction orthosis should be abandoned in Perthes' disease.

Treatment outcome in the most severely affected Legg-Perthes patients, comparing prolonged traction in abduction with femoral varus derotation treatment

“…Several reports do compare conservative containment treatment to femoral osteotomy, even though all report on other conservative containment regimens (e.g., abduction plasters, abduction orthosis or weight relieving calipers). Furthermore, most studies include less severely affected patients (i.e., Catterall 1 and 2), use other operative methods as well and/or use divers classification and outcome parameters [13,14,17,20,[33][34][35][36][37][38][39]. Some of these studies report better results for conservative regime [17] or femoral osteotomy [37,38].…”

The natural history of Perthes' disease

“…Studies on prognosis have to account for these risk factors and the number of patients has to be large to make the statistical analysis of subgroups meaningful and reliable. These requirements were met by the Norwegian nationwide prospective study on Perthes' disease in which 368 children with unilateral affection were included (Wiig et al 2008). A large proportion of the patients were managed by physiotherapy only.…”

Legg-Calv�-Perthes disease: classifications and prognostic factors

“…In 2009, another modification of this classification (7) was published, dividing Stages C into Stage C1, involving <75% of the lateral pillar, and C2, involving > 75%. The prognostic value of this classification has been confirmed since (5,6,8,15,16). It is also the classification with the best intra-and inter-observer reproducibility (17).…”

“…It is the oldest classification (1971) and encompasses 4 stages, each of which is associated to a prognostic value (9). In 2008, a modified Catterall classification was proposed, due to poor reproducibility of the original one (6 (Table 4) It was published in 1992, because of the poor reproducibility of that of Catterall. It is also known as the "lateral pillar classification".…”