Intraobserver and interobserver reliability of Kalamchi and Macewen's classification system for evaluation of avascular necrosis of the femoral head in developmental hip dysplasia.

This study evaluates the intraobserver and interobserver reliability of the Kalamchi and MacEwen's classification system of avascular necrosis of the femoral head. Radiographs of 48 developmentally dysplastic hips that had an average follow-up of 40.5 months (range: 36 to 52 months) and that had been treated by the same operative technique were interpreted twice by four experienced pediatric orthopaedic surgeons. When the absence or presence of avascular necrosis was taken into consideration the average intraobserver agreement percentage and kappa coefficient were 86% and 0.71, respectively. The average interobserver agreement percentage and kappa coefficient were 83% and 0.66, respectively. When the agreement on the type of avascular necrosis was analyzed, the average intraobserver agreement percentage and kappa coefficient were 85% and 0.74, respectively. The average interobserver agreement percentage and kappa coefficient were 81% and 0.66, respectively. No statistically significant difference was found between the rates of avascular necrosis of four observers. The Kalamchi and MacEwen's classification system was found to be reliable and reproducible.

Severin classification system for evaluation of the results of operative treatment of congenital dislocation of the hip. A study of intraobserver and interobserver reliability.

The Severin classification system frequently is used to evaluate the radiographic results of operations performed for the treatment of congenital dislocation of the hip. However, the reliability of this classification scheme has not been established, to our knowledge. Ideally, a classification system should be validated before it is used to promote therapeutic guidelines or to compare results of treatment; the purpose of the present study was to establish the intraobserver and interobserver reliability of the Severin classification system. Four blinded raters and the operating surgeon independently used the Severin system to evaluate the most recent radiographs of thirty-seven children (fifty-six hips) who had been managed, an average of nine years previously, with a medial open reduction for congenital dislocation of the hip. Three of the raters evaluated the same radiographs again under similar testing circumstances eight weeks later. Ten paired interobserver and three intraobserver comparisons then were analyzed with use of the Cohen kappa coefficient (kappa). The average kappa coefficient for the six pairwise comparisons between the four blinded raters was 0.15 (range, -0.05 to 0.42) when all Severin classes were analyzed independently. The average kappa coefficient for the four pairwise comparisons between the blinded raters and the operating surgeon was even lower (0.02). The kappa coefficients for the three intraobserver comparisons were 0.20, 0.38, and 0.44 (average, 0.34). Kappa analysis demonstrated variable and low levels of agreement when the Severin system was used to rate the results of operations performed for the treatment of congenital dislocation of the hip. We believe that the unadjusted kappa coefficient should indicate excellent agreement (kappa > 0.75) for all comparisons if this system is to be used for the evaluation of clinical results. The unacceptably low levels of intraobserver and interobserver reliability call into question the clinical conclusions of reports in which the Severin system has been used as the basis of proof.

Medial open reduction in the treatment of developmental dislocation of the hip.

Fifty-six developmentally dislocated hips occurring in 37 children with an average age of 11.2 months (range, 2-25) underwent medial open reduction without preliminary traction by Ferguson's approach. Follow-up averaged 8.1 years (range, 3-17). Ninety-eight percent of hips were rated either excellent or good at final follow-up (Severin I or II). Eleven (19%) hips required secondary bony reconstructive procedures. Five (8.9%) hips demonstrated evidence of avascular necrosis. The authors conclude that medial open reduction is a safe and effective surgical treatment for developmental dislocation of the hip in the child younger than 2 years.

Posterior iliopsoas transfer: a treatment for some myelodysplastic hips.

A retrospective study of our 16-year experience in utilizing posterior iliopsoas transfer as treatment for the neurogenic dislocated hip is presented. Fifty-four surgically treated hips are compared with 20 hips treated nonoperatively. Maintenance of location was achieved in 84% of the operated hips. All of the postoperative dislocations can be explained by failure of the surgeon to adhere to the essentials of tendon transfer.