CLASSIFICATION IN SLIPPED CAPITAL FEMORAL EPIPHYSIS - SONOGRAPHIC ASSESSMENT OF STABILITY AND REMODELING

In a prospective study of 26 hips in 21 patients with slipped capital femoral epiphyses (SCFEs), serial sonography was more sensitive than r adiography in showing epiphyseal displacement and reduction. Reduction s were associated with grossly visible hip joint effusions. The initia l slips were reduced by treatment in seven of 11 hips with effusion. T he 15 hips without effusion were unreduced. After stabilization and pi nning, the effusion did not recur in any case. Sonography is sensitive and free from projectional errors in the assessment of metaphyseal re modeling. If any remodeling is present, the SCFE is at least three wee ks in duration. A new classification into acute, acute-onchronic, and chronic SCFEs is proposed, based on the objective sonographic data. Jo int effusion represents physeal instability or recent progression, and remodeling is a sign of chronicity. An acute SCFE is characterized by effusion, whereas a slip without effusion but with remodeling is desi gnated as chronic. An acute-on-chronic SCFE is associated with both ef fusion and remodeling. Joint effusion suggests that SCFEs should be op eratively fixed and that displacement may diminish with traction or in traoperative positioning of the hip.