A Radiographic Classification System for Intracapsular Hip Fractures that Reflects Fracture Displacement and Predicts Complications after Internal Fixation: A Clinical Study of 2262 Patients

Abstract

Introduction: Intra-capsular hip fractures may present on a spectrum from clinical suspicion of an un-displaced fracture on the radiograph, to off-ended with no overlap between fracture fragments. Existing classification systems such as AO, Garden, and Pauwels classifications attempt to describe this, but they rely purely on the Antero-Posterior (AP) radiograph. These classifications have all been found to be unreliable. In this study we propose a new classification system that details the progressive displacement of an intra-capsular fracture into six grades based on the fracture characteristics on the AP and lateral radiographs. The aim is to determine if this classification system is predictive of the occurrence of fracture non-union or Avascular Necrosis (AVN) and compare against traditional classification methods.

Method: Data was collected from 2,262 intra-capsular hip fractures undergoing internal fixation between May 1989 and April 2019 at Peterborough City Hospital.

Results: Fracture non-union was observed for 338 (12.9%) patients and avascular necrosis in 141 (5.4%) patients. The risk of fracture non-union increased for greater degrees of fracture displacement (5.2% to 36.8%, p<0.0001). For AVN the risk increased from 0.0% to 7.1% (p<0.0001) with increasing displacement. The overall risk of developing a fracture healing complication increased with progressive displacement (5.2% to 43.9%, p<0.0001). When classified using Garden classification; both non-union and avascular increased with increasing grade (non-union 5.9% to 22.9% p=0.001), AVN (4.0% to 8.1% p=0.0001), and overall fracture healing complications (9.8% to 31.0%, p=0.0001).

Conclusion: The new classification system was found to be highly predictive of fracture healing complications following internal fixation of an intra-capsular fracture. We have also demonstrated significant improvement in predicting fracture healing complications compared to the abilities of the established classification system. Thus, this new classification system can be used to guide operative decision making.

Keywords: Hip Fracture; Intra-capsular; Fixation; Non-Union; Fracture Healing Complications

Citation

Martyn J Parker. A Radiographic Classification System for Intracapsular Hip Fractures that Reflects Fracture Displacement and Predicts Complications after Internal Fixation: A Clinical Study of 2262 Patients. WebLog J Orthop. wjor.2026.g0902. https://doi.org/10.5281/zenodo.21436323