Review Question - QID 213000

The patient is presenting with increased pain and weakness due to lesser tuberosity nonunion following total shoulder arthroplasty.

Total shoulder arthroplasty performed through a standard deltopectoral incision requires takedown of the subscapularis in order to access the glenohumeral joint. Options for takedown include tenotomy of the subscapularis tendon, subscapularis peel, or lesser tuberosity osteotomy, which has gained interest due to the higher biomechanical strength of bone-to-bone healing. Nonunion of the lesser tuberosity osteotomy can lead to very poor outcomes for affected patients, with many requiring several revision procedures.

Shi et al. report a case series of patients that had nonunion of the lesser tuberosity osteotomy following total shoulder arthroplasty. The authors found there were poor clinical outcomes in these patients with few presenting with a history of trauma and most requiring revision to reverse total shoulder arthroplasty. They recommended augmenting the lesser tuberosity repairs with a tension band construct in high-risk patients at the time of the index procedure.

Small et al. performed a review of a large series of patients undergoing a lesser tuberosity osteotomy for total shoulder arthroplasty. The authors found there to be an 11% nonunion rate of the osteotomy, with young males being at higher risk. The authors recommend the use of orthogonal radiographs when assessing the union of the lesser tuberosity osteotomy and that younger fit males must be reminded to follow postoperative protocols.

Matsen et al. performed a review of glenoid component failure in total shoulder arthroplasty. The authors reported that conforming articular surfaces and flat bone cuts contribute to the "rocking-horse" failure mechanism. They also reported that the presence of radiolucent lines adjacent to the glenoid component is associated with increased failure rates.

Steinmann et al. reviewed the treatment of periprosthetic humeral shaft fractures. Loose prostheses necessitate revision long stem component with supplementary fixation, whereas well-fixed stems with fractures at the tip or proximal require hybrid plate fixation. Fractures distal to the tip can be treated non-operatively, but in the presence of nonunion may require plate fixation with or without allograft struts.

Figure A demonstrates an axillary radiograph of the right shoulder with a nonunion of the lesser tuberosity. Illustration A depicts the Wright and Cofield classification for periprosthetic humeral shaft fractures. Illustration B depicts a diagram detailing the rocking horse mechanism of glenoid component failure.

Incorrect Answers:
Answer 1, 2, 3, 5: These can all cause symptoms of weakness, pain, decreased range of motion, and instability following total shoulder arthroplasty; however, this patient's radiograph demonstrates nonunion of the lesser tuberosity, which is consistent with the patient's physical exam.