Rapidly destructive osteonecrosis of the humeral head after arthroscopic rotator cuff repair: a case report

Background: Cases of rapidly destructive osteonecrosis (RDON) of the humeral head after arthroscopic rotator cuff repair (RCR) have rarely been reported, which has prevented a clear consensus on the cause of osteonecrosis. Case presentation: A 63-year-old woman without a history of trauma underwent arthroscopic RCR after being diagnosed with a medium-sized full-thickness rotator cuff tear for symptoms of left shoulder pain for six months. The patient had no medical history other than hypertension, and no other potential cause was found for osteonecrosis of the left shoulder prior to surgery. Four months after surgery, pain and range of motion improved. Six months after surgery, the patient complained of an increase in shoulder pain. While follow-up ultrasonography did not show a re-tear of the repaired tendon, osteonecrosis of the humeral head could not be confirmed as plain radiography was not performed. Follow up MRI performed a year after surgery revealed RDON of the humeral head. Despite mild improvement in the shoulder pain, the Shoulder Rating Scale of the University of California at Los Angeles (UCLA) and Constant score were poor at 23 and 69, respectively. In the present case, the arthroscopic RCR was performed using two anchors; for the repair of the anterior of the supraspinatus and the rotator interval, a 2.8-mm all-suture anchor was inserted into the upper part of the intertubercular groove. The cause of RDON is presumed to be the damage to the anterolateral and intraosseous branches of the anterior humeral circumflex artery (AHCA) for anchor positioning and insertion. Conclusions: A poor outcome was obtained in the case of RDON, despite the integrity of the repaired rotator cuff tendon after arthroscopic RCR was intact. Although the cause of RDON has not been clearly established, care should be taken not to damage the anterolateral and intraosseous branches of the AHCA regarding the insertion location of the suture anchor, and to prepare the anchor in the vicinity of the intertubercular groove.