The height-to-width index for the assessment of femoral head deformity following osteonecrosis in the treatment of developmental dysplasia.

BACKGROUND: The principal complications that follow the treatment of developmental dysplasia of the hip are redislocation and growth disturbance of the femoral head and neck as a result of osteonecrosis of the femoral epiphysis. Growth disturbance secondary to osteonecrosis is difficult to determine until long after the treatment episode has passed. Consequently, the treating surgeon has little early feedback regarding the long-term consequences of management interventions. We therefore sought to devise a quantitative method to identify early evidence of growth disturbance related to osteonecrosis. METHODS: The width and height of the epiphyses were measured on anteroposterior radiographs of the pelvis made twelve to eighteen months after successful closed reduction and on the latest available radiograph for each patient (mean age, 8.6 years). The epiphyseal index was calculated by dividing the height by the width. The radiographs were also scored for osteonecrosis with use of the Kalamchi and MacEwen classification system and were also assessed for sphericity with use of Mose rings. RESULTS: Forty-seven patients with late-presenting developmental dysplasia of the hip who subsequently underwent successful closed reduction were included. An index of <0.357 on the twelve to eighteen-month post-treatment radiograph strongly predicted the development of a nonspherical femoral head on the latest radiograph (sensitivity, 0.83; specificity, 0.95; positive predictive value, 0.55; and negative predictive value, 0.99). CONCLUSIONS: The height-to-width index appears to be a simple and quantifiable measurement of the severity of growth disturbance as a consequence of osteonecrosis following treatment for developmental dysplasia of the hip. It is predictive of asphericity at the time of intermediate-term follow-up and appears likely to predict asphericity at maturity, but this must be confirmed with follow-up to maturity. Unlike the currently used methods of assessing osteonecrosis, the index allows for the quantifiable evaluation of growth disturbance within a few years after the corrective procedure.

Post-operative mortality related to waiting time for hip fracture surgery.

UNLABELLED: In this retrospective study, we looked at the difference in 1 year mortality between two groups of patients who were operated for fracture of the hip. PATIENTS AND METHODS: In cohort 1, 72% of the patients underwent surgery on the same day of admission, 15% of the patients were operated on the next day, the remaining 13% of the patients waited more than 1 day for surgery. The mean waiting time was 0.47 day. The percentage of patients who were operated on the same day of admission in cohort 2 was 18%. Sixty-nine percent of the patients had to wait 1 day before they were operated and 13% waited 2 days or more. The average waiting time was 1.01 days. The date of death for both the 166 patients in cohort 1 and the 197 patients in cohort 2, was obtained from the national mortality register and the 1 year mortality was calculated. These two groups of patients were from separate 12 month periods and the operations performed were either Dynamic Hip Screw (DHS) or hemiarthroplasty. The two groups were comparable in gender, age distribution and the types of operations. RESULTS: There was an increase of 10.1% (P<0.025, chi(2), 1 d.f.; 95% CI 1.7-18.5) in the mortality of patients in cohort 2. The mortality data of the two cohorts was also analysed after dividing the patients into three groups according to their age. A statistically significant increase in mortality of 16.9% in patients over 80 years of age in cohort 2 was found. The difference in mortality was still statistically significant when only patients over 80 years of age and having a DHS operation were compared. Total mortality at 2 years after the operation was the same in the two cohorts. Mortality rate for patients in cohort 2 was less than that for cohort 1 patients during the second post-operative year. CONCLUSION: This study shows that survival at 1 year is better when patients who are medically fit for surgery are operated on the same day of admission. This survival advantage is more pronounced for patients who are over 80 years of age.