Patient RF was a 42-year-old man who had a left side os acromiale with an impingement syndrome. He was first treated by a colleague orthopaedic surgeon, who performed three surgeries. The first was an arthroscopic limited decompression, followed by fixation with K-wires and tension band wiring. Because of an infection and perforation of the osteosynthesis materials, they were removed and replaced by two Acutrak screws. However, a monitoring CT showed loosening of these screws. The patient continued to suffer from a loss of strength and pain at night. As an alternative approach, an osteosynthesis using a distal clavicle osteosynthesis plate was performed. Fixation was achieved using cortical and angle-stable locking screws (4 × 10 mm and 2 × 12 mm). One compression screw was used. A bone graft was harvested from the left iliac crest and applied at the osteotomy site.
Patient TR was a 67-year-old woman who had a left-side os acromiale together with a rotator cuff tear, a type of partial articular supraspinatus tendon avulsion and a biceps hourglass impingement. The first operation (2009) was an arthroscopic decompression, biceps tenotomy and rotator cuff repair. Because of recurrent pain with documented impingement syndrome, an osteosynthesis with an osteosynthesis plate was performed. An osteotomy of 1 mm was performed either side of the non-union. Fixation was achieved using cortical and angle-stable screws (14 or 16 mm) and one compression screw was used. Her acromion was so small that the usual procedure of inserting 3.5-mm hollow screws was not possible. The bone remnants were pulverized and used as a bone graft.