In the cranial humeral end, osteochondral injuries localize in a circular crown including part of the humeral head and part of the major and minor tuberosities. Since this region is easy to depict with US, we investigated the potentials of this technique in detecting osteochondral injuries.
Seventy-five osteochondral injuries found at 492 US examinations performed in 12 months with a 7.5 MHz linear probe were retrospectively reviewed. Clinical history taking was focused on the following: a) previous trauma or b) luxation-instability and c) if the patient was a sportsman devoted to activities requiring forced abduction-external rotation or adduction-internal rotation. Since the site of the head's humeral injury is an important clue for diagnosis, we subdivided the humeral circle into four ideal quadrants by two perpendicular lines with the main line passing through the bicipital groove. Then, each injury was ascribed to a quadrant. All patients were also submitted to radiography (at least two films) and to MRI; CT was performed in 12 patients. Ten patients underwent surgery.
We found 34 Hill-Sachs lesions, 15 traumas, 9 arthrotic lesions, 7 cases of anterointernal and 4 of posterosuperior impingement, 4 cases of infraspinatus enthesopathy and 2 erosions due to perihumeral calcifications. In our experience, US was an accurate tool in the identification of humeral head conditions, which were confirmed at CT and/or MRI in all patients (no false positives). As for the injury nature, US diagnosis was confirmed in all Hill-Sachs lesions (34/34 cases), traumas (15/15 cases) and 50% of the cases of posterosuperior impingement (2/4 cases). These conditions made up about 2/3 of the whole cases (51/75 cases). US failed to establish the injury nature in the 9 arthrotic lesions, 7 cases of anterointernal impingement, 4 cases of infraspinatus enthesopathy and 2 erosions due to perihumeral calcifications.
US can be suggested as the method of choice in the study of the osteochondral lining of the humeral head.