Influence of risk factors and therapy on hip deformity in Legg-Calve-Perthes disease.

Problem: The prognostication of risk factors for the outcome of LCPD was ex amined. The radiographic results of conservative treatment with Thomas spli nt and operative treatment with intertrochanteric derotational varus osteot omy (DVO) were compared using the Index of Deformity (D). Method: Radiograp hs of 153 patients with unilateral LCPD were evaluated retrospectively 1.5- 3 years and 3-7 years after diagnosis using the Index of Deformity and Inde x of Direction. We investigated the radiographic changes in relation to ace tabular or metaphyseal reaction, Waldenstrom classification or limited rang e of motion at diagnosis and in dependence of therapy. Results: There was a significant better acetabulum-head-index of deformity after DVO. Children with metaphyseal or acetabular reaction had bigger deformities. Patients wi th metaphyseal reaction had smaller deformities after DVO compared with con servative treatment. Free range of motion (ROM) was prerequisite for good r esults after DVO. Waldenstrom classification at diagnosis did not have any influence on morphologic changes after 3-7 years. Conclusion: DVO leads to a better containment than conservative treatment with Thomas splint, metaph yseal reaction should be an indication for operative treatment. Prerequisit e for DVO is a free ROM. Because Waldenstrom class at diagnosis does not in fluence the outcome, free ROM before starting the treatment is more importa nt than an immediate start of therapy.