Accuracy of clinical and radiographic measurements for detecting significant shortening in acute midshaft clavicle fractures: a cross-sectional study with computed tomography scan as the reference standard.

BACKGROUND

Operative intervention is now frequently recommended for displaced midshaft clavicle fractures with shortening exceeding 15-20 mm. Accurate measurement of clavicular shortening is therefore critical for therapeutic decision-making. The diagnostic validity and reliability of the commonly used clinical and radiographic measurement methods remain subjects of debate. The purpose of this study was to evaluate the validity and interobserver reliability of clinical and radiographic measurements of acute clavicular fracture shortening using computed tomography (CT) as the criterion standard and to evaluate their diagnostic performance to detect the shortening cutoff value of 15 mm.

METHODS

Fifty-one corresponding measurements (clinical, radiography, and CT) for fractured clavicles with similar measurements for their normal contralateral side were evaluated by 2 experienced examiners. Shortening is then computed as the difference in length from the normal clavicle length. In addition, a combined clinical-radiographic measurement method was calculated for each patient. All patients had midshaft clavicle fracture without initial cortical contact and underwent the 3 clavicle measurements within the first 3 days after admission.

RESULTS

All 3 index methods demonstrated poor agreement with CT measurements. Intraclass correlation coefficients were very low, and Bland-Altman analysis confirmed significant bias and wide limit of agreement for each method. Clinical and radiographic measurements were more specific than sensitive but with overall low accuracy. Combining clinical and radiography assessment improved specificity. The radiographic method was more reliable than clinical assessment.

CONCLUSION

Due to the detected wide measurement error, clinical examination and radiography are insufficient for determining operative indication.