Isolated lesions of the lower subscapularis tendon: diagnosis and management

Purpose: Isolated lesions of the caudal portion of the subscapularis (SSC) tendon are rare and have not been subject of major attention in the literature yet. However, these lesions can lead to tremendous impairment of shoulder function. The purpose of the present study was to raise clinician’s awareness for these “hidden lesions” and to present the crucial steps for diagnosis and management. Methods: Five patients (three men, two women; mean age 40) with traumatic isolated caudal SSC lesion were enrolled in the present study. After clinical and radiological examination, all patients underwent diagnostic arthroscopy and open inferior SSC repair. The results of the clinical and radiological examination were documented along with the intraoperative findings. Post-operative pain level and shoulder function were assessed. Results: In all patients the SSC lesion could be detected clinically. In two patients the caudal SSC tear was diagnosed delayed after initial conservative treatment. Preoperatively, all patients showed restricted active movement of the shoulder with positive clinical tests for the SSC. All SSC lesions could be detected on MR images and identified arthroscopically. After a mean follow-up of 12 months, all clinical SSC tests were negative, and the patients have almost regained preinjury shoulder function. The mean post-operative pain score (VAS) was 1 (range 0–1), and the mean ASES score was 93.3 (range 91.6–95). Conclusion: Arthroscopic visualization of the SSC tendon is incomplete rendering caudal SSC tears difficult to detect and easy to overlook. Clinicians’ awareness of this pathology along with accurate clinical and radiological examination leads to the correct diagnosis. Open caudal SSC repair provides pain relief and reliable shoulder function after short-term follow-up. Level of evidence: IV.