Post-op CT more accurately detects screw penetration in arm fractures

Postoperative CT, most notably 3D CT scans, are the preferred imaging technique in evaluating intra-articular screw penetration of proximal humerus fractures, according to a study published in Academic Radiology.

Proximal humerus fractures are the third most common type of breakages. Recently, locking plates have become the preferred method of treatment, but this method includes risk with the rate of screw penetration beyond the humeral cortex is up 10 to 15 percent, wrote Yanxi Chen, MD, PhD with the Tongji University School of Medicine in Shanghai.

For surgeons to be confident in a diagnosis, postoperative radiological evaluation is necessary to determine if screws penetrated the joint, but the standard radiography may not detect this, Chen and colleagues wrote.

“Therefore, the ability of plain radiography alone to evaluate intra-articular screw penetration is questionable,” Chen et al. added.

Radiological images of 134 patients who sustained proximal humerus fractures treated with locking plates were examined by two observers. They were then asked two questions:

Is there screw penetrating into glenohumeral joint for this patient?

On a scale from zero to 10, how confident are you about this diagnosis?

Three evaluations were performed: plain radiography alone, radiography and 2D CT four weeks later and radiography in combination with 2D and 3D CT after that.

“In this study, we found that postoperative CT could detect more screw penetration than conventional plain radiography, and it was more reliable. Meanwhile, surgeons felt more confident about their diagnoses when CT images were used,” Chen et al wrote. “Although there was no significant difference in the detection of screw penetration with addition of 3D CT to 2D CT and radiography, the confidence in the diagnosis was higher with the addition of 3D CT.”