Pediatric Lateral Humeral Condyle Fractures: Reliability of a Modified Jakob Classification System and its Impact on Treatment Planning With or Without Arthrography

Abstract

Background: Various lateral humeral condyle fracture (LHCF) classification systems have been in use since the 1950s, but limited research exists on their reliability. The most widely utilized, yet un-validated system is that of Jakob and colleagues. The purpose of the current study was to analyze the reliability of a modified Jakob classification system and its value in guiding treatment either with or without arthrography. Methods: Interrater and intrarater reliability studies were performed using radiographs and arthrograms from 32 LHCFs. Radiographs were presented to 3 pediatric orthopaedic surgeons and 6 pediatric orthopaedic surgery residents who were asked to classify the fractures according to a modified Jakob classification system, enunciate their treatment plan, and whether they would utilize arthrography. Classification was repeated within 2 weeks to assess intrarater reliability. The treatment plan using radiographs only and radiographs with arthrography were compared at both rating points. Results: The modified Jakob system had excellent interrater reliability using only radiographs with a kappa value of 0.82 and an overall agreement of 86%. The average kappa for intrarater reliability using only radiographs was 0.88 with a range of 0.79 to 1.00 and an average overall agreement of 91% with a range of 84% to 100%. Interrater and intrarater reliability was poorer using both radiographs and arthrography. On average, arthrography changed the treatment plan in 8% of cases. Conclusions: The modified Jakob classification system proved to be a reliable classification system for LHCFs, independent of arthrography, given the excellent free-marginal multirater kappa values. Level of Evidence: Level III—diagnostic.