Internal Rotation Traction Radiograph Improves Proximal Femoral Fracture Classification Accuracy and Agreement.

OBJECTIVE: The objective of this study is to assess the clinical utility of internal rotation traction radiography in the classification of proximal femoral fractures.

MATERIALS AND METHODS: The study cohort included 78 consecutive patients who were surgically treated for a proximal femoral fracture and for whom preoperative physician-assisted internal rotation traction radiographs of the fractured hip were obtained in addition to standard radiographs. Two radiologists who were blinded to clinical information independently classified each fracture without the traction view and then with the traction view. The radiologists also reported their confidence (expressed as a percentage) in their classifications. The reference standard was the consensus interpretation of intraoperative C-arm fluoroscopic images by two orthopedic surgeons and one radiologist. Classification accuracy was compared using the McNemar test. Subjective confidence and confidence-weighted accuracy were compare using paired t tests. Agreement with the reference standard and interreader agreement were calculated using the kappa statistic and were compared using the z-test after bootstrapping was performed to obtain the standard error.

RESULTS: With the traction view, the pooled accuracy increased from 44.9% to 72.4%, subjective confidence increased from 87% to 94%, and confidence-weighted accuracy increased from 51.7% to 74.3% (p < 0.001). With the traction view, the kappa statistic for agreement with the reference standard increased from 0.530 to 0.791 and from 0.381 to 0.625 for the two readers, and interreader agreement increased from 0.480 to 0.678 (p < 0.001).

CONCLUSION: The addition of an internal rotation traction radiographic view significantly improves radiologist accuracy and confidence as well as interreader agreement in the classification of proximal femoral fractures, all of which would be expected to best guide appropriate surgical management.