Sensitivity and Specificity of Radiographs in the Diagnosis of Little and/or Ring Carpometacarpal Joint Injuries.

Introduction  Little and ring finger carpometacarpal joints (CMCJs) injuries are commonly missed due to misinterpretation of radiographs. We aimed to determine the sensitivity and specificity of four different radiographic views. Materials and Methods  Radiographs (posteroanterior [PA], lateral [LAT], pronated oblique [POL], and supinated oblique [SOL] views) showing normal findings or little/ring finger CMCJ injuries were shown to two cohorts of orthopaedic trainees and a cohort of emergency nurse practitioners. Results  The POL view performed best in all three testing scenarios. The SOL view performed least well. The combination of a PA, true LAT, and POL identified 78% of injuries correctly. In no cases did the SOL view correctly identify an injury when the other three views had been interpreted as normal. Conclusion  We recommend a combination of the PA, POL, and LAT views in diagnosing these injuries. Where doubt remains, cross-sectional imaging is essential.