Die winkelstabile Osteosynthese am proximalen Humerus mit der PHILOS-Platte

BACKGROUND: Proximal fracture of the humeral head is the third most frequent fracture in humans. Most (70%) of those affected are over 60 years old. It is hoped that advanced locking medullary screws or plates will reduce the risk of secondary dislocation of screws or fracture segments when the bone of the humeral head is osteoporotic. METHODS: From January 2002 to August 2005, 225 displaced humeral head fractures in 223 patients aged on average 66+/-15 years were treated with a new locking proximal humeral plate. RESULTS: In 176 patients in whom follow-up was possible, the average Constant Score after 9 months was 70+/-19 points (raw data), or 81+/-22% in the normalized score. No significant difference was detected between the younger group up to 65 years of age (73% points) and those over 65 years of age (80% points). Axial deviations by more than 30 degrees were noted in 11 (5%), and of 159 displaced tubercles, malreduction by more than 5 mm was noted in 14 (9%). Two infections and two haematomas had to be treated so far. Primary screw perforations were seen in 24 (11%) cases as well as further implant dislocations in 3 (1,7%). Plate dislocations out of the shaft existed in 4 (2,4%) and 14 collapses of the humeral head with secondary screw perforations were recorded. All other complications arose out of technical faults, such as 24 screw perforations (11%) into the glenohumeral joint and 3 (1.7%) cases of secondary implant dislocation from the humeral head and 5 (3%) from the shaft, and 14 (8%) sinterings with glenohumeral screw perforation. So far, in addition to 1 case of pseudarthrosis with a broken plate, 5 (3%) cases of total and 9 (5%) of partial avascular humeral head necrosis have been observed. CONCLUSION: The new implant provides superior stability in the fixation of humeral head fragments and has proved its worth in everyday clinical practice when additional indirect fixation of the tubercle is needed, as it frequently is in elderly patients.