Patient PW was a 48-year-old male triathlete who had bilateral os acromiale, but only the left side was locally symptomatic. The acromion was sensitive on palpitation and after swimming. All impingement signs were negative and the ultrasound and magnetic resonance imaging (MRI) showed marked oedema at the os acromiale but did not reveal any rotator cuff tendinopathy. The patient was first treated with local conservative therapy. This included physical therapy with ice and an infiltration of the os acromial joint with Kenacort and Xylocaine 2%. This gave immediate pain relief for a few hours. Conservative treatment was unsuccessful, meaning that an operation was necessary. In this case, nine screws (2.7- and 3.5-mm) were used. Six anterior angle-stable screws were necessary. Posteriorly two cortical screws (one of which was used for compression) and two angle-stable locking screws were used. Because of the congenital or primary pseudarthrosis, an osteotomy of 1 mm was performed on each side of the osseous non-union including the cranial osteophytes. These bone remnants were pulverized and replaced between or lateral to the plate and the osteotomy site. The control radiography showed correct positioning.
Patient VR was a 60-year-old homeless male. He experienced a frontal collision on his motorcycle under the influence of alcohol. He had a history of alcohol, nicotine and heroin abuse. He complained about pain in his right shoulder. A CT showed fractures of the acromion, the coracoid process with an intra-articular glenoid component, the scapula tip and three rib fractures. These fractures could be classified according to the LSSS as S1b and S2c fractures, without including the concomitant scapular tip fracture and three rib fractures (Lambert et al., ). This scapular fracture was similar to that of patient VL, and there was also a rupture of the AC ligaments, which caused instability.\nThis fracture was set using an osteosynthesis plate and six anterior 12-mm angle-stable locking screws and three posterior compression screws. The AC ligaments were repaired and the coracoid fracture was treated the same way as that of patient VL. A monitoring X-ray showed good positioning of the osteosynthesis plate and screws.