Successful treatment of fractures of the base of the acromion after reverse shoulder arthroplasty: Case report and review of the literature
A 71-year-old right-handed woman presented with a 2-year history of right shoulder pain and dysfunction, which began abruptly when lifting a heavy load. At the initial evaluation, her range of motion was limited, particularly in active abduction as she achieved only 45 degrees in this plane. A cuff arthropathy (Hamada grade 3) was diagnosed and the decision was taken to proceed with reverse shoulder arthroplasty. To complete the pre-operative assessment, a CT scan was performed which confirmed there was no acromial pathology involved.\nA reverse shoulder prosthesis and a biceps tenodesis was carried out (Delta Xtend™, Depuy, Warsaw, IN, USA) through a deltopecoral approach []. The patient's right arm was immobilized in a sling and the range of motion exercises were started 6 weeks after arthroplasty []. Five months after surgery, she sustained a blow to the right shoulder but sought medical attention 1 month later, at her scheduled follow-up visit. Radiographs showed a displaced fracture at the base of the acromion []. A CT scan was performed to better characterize the fracture. This showed that both the humeral and glenoid components were well fixed and the only pathology was the fracture.\nShe was taken to the operating room and her previous incision was extended into a “sabre” incision to better expose the acromion. Two small fragment (3.5 mm) locking plates (Synthes, West Chester, PA, USA) were used in a 90/90 configuration; one was a fragment specific clavicular plate and the other a reconstruction plate. The fragment specific clavicular plate was applied on the superior edge of the scapular spine in a compression mode. Distally, 2.7 mm locking screws were used. A second reconsrtuction plate was applied from the posterior acromion to the posterior cortex of the scapular spine, in the infraspinatus fossa. Long screws were placed from the posterior to the anterior acromion. Fixation was solid, but in order to protect the construct, the patient was placed in an abduction brace for 6 weeks.\nEighteen months after fracture fixation, the patient was satisfied with the clinical result []. She was capable of 125 degrees of abduction, 160 degrees of forward flexion, 85 degrees of external rotation in adduction, and 60 degrees of internal rotation. Her QuickDASH score was 29.5 (compared to 82.5 pre-op) and Constant score was 69 on the affected side compared to 85 on the left side, for a “good” functional outcome.