Reliability of Bucholz and Ogden classification for osteonecrosis secondary to developmental dysplasia of the hip.

BACKGROUND: Osteonecrosis is perhaps the most important serious complication after treatment of developmental dysplasia of the hip (DDH). The classification by Bucholz and Ogden has been used most frequently for grading osteonecrosis in this context, but its reliability is not established and unreliability could affect the validity of studies reporting the outcome of treatment. QUESTIONS/PURPOSE: We established the interrater and intrarater reliabilities of this classification and analyzed the frequency and nature of disagreements. METHODS: Three pediatric hip surgeons, a musculoskeletal pediatric radiologist, and three orthopaedic trainees graded 39 radiographs (hips) according to the Bucholz and Ogden classification, blinded to any clinical data. Ratings were repeated after 2 weeks. Interrater reliability and intrarater reliability were determined using the simple kappa statistic. Grading was compared among raters, the nature and frequency of disagreements established, and subgroup analyses performed. RESULTS: Interrater reliability was 0.34 (95% CI = 0.28, 0.40) for all raters, and 0.31 (0.20 to 0.43) for the three surgeons. The best interrater reliability was observed between the radiologist and a surgeon with a kappa of 0.51 (0.30, 0.72). Intrarater reliability estimates ranged from 0.44 to 0.69. Raters disagreed regarding the grade of osteonecrosis in 26 of 39 hips (67%), with seven of 26 disagreements (27%) involving confusion between Grades I and II. CONCLUSIONS: The interrater reliability was lower than expected, considering the raters' experience. Distinguishing between Grades I and II was the most frequently observed problem. We believe that the low reliability was a result of an ambiguous classification scheme rather than the variability among the raters. Outcome studies of DDH based on this classification should be interpreted with caution. We recommend the development of a new classification with better prognostic ability. LEVEL OF EVIDENCE: Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Transitional fractures of the distal tibia: a minimal access approach for osteosynthesis.

BACKGROUND: Transitional fractures typically occur in patients with partially closed growth plates. In case of displacements >2 mm, osteosynthesis is recommended. Open reduction and stabilization with lag screws is the most common approach. Infection and paraesthesia are common complications of this method. This study describes an alternative approach by closed reduction and cannulated screw fixation. METHODS: All patients with transitional fractures treated by closed reduction and cannulated screw fixation were identified. All patients with >1 year after implant removal were included in this investigation. Of 27 patients treated by this technique, 21 met the inclusion criteria and were sent a standardized questionnaire including the Foot Function Index (FFI). All cases with impairments in the FFI were invited for a follow-up examination. RESULTS: Postoperative complications occurred in two patients (8.3%): one reported paraesthesia of the hallux and one showed skin irritations above the screw insertion. Average follow-up time was 3.8 years after implant removal. Of 21 patients who returned the questionnaire, three patients (14.3%) had impairment in the FFI and were invited for clinical follow-up: one patient showed mild signs of osteoarthritis without visible gaps of the joint surface, one patient had minimally restricted pronation, and one had neither clinical nor radiologic correlates for the impairment reported. Sports activity was reduced in one patient. CONCLUSION: If closed reduction can be achieved fixation with cannulated screws proved to be a satisfactory method with little scars and good clinical results.