Operative treatment of greater tuberosity fractures of the humerus--a biomechanical analysis.
BACKGROUND
Fractures of the greater tuberosity of the humerus present with increasing frequency. However, no biomechanical data about the optimal fixation technique of greater tuberosity fractures is available. This biomechanical cadaver study compares the stability of three standard fixation techniques used for the treatment of greater tuberosity fractures of the proximal humerus.


METHODS
In 21 fresh frozen proximal humeri, standardized fractures of the greater tuberosity were created. The specimens were randomly assigned to one of three operation techniques: wire tension banding, two cancellous screws and transosseous sutures. These constructs were mechanically tested by applying an increasing force to the supraspinatus tendon. Load to 5mm displacement (load to 5mm yield point) and load to failure (maximum stretch strength) were measured in Newton (N).


RESULTS
Load to 5mm yield point values showed no significant differences between tension banding (498 N, SD 153) and two cancellous screws (400 N, SD 174) (P>0.01). Both techniques showed significantly higher values than transosseous sutures (185 N, SD 132) (P<0.01). Load to failure values were significantly higher for tension banding (1054 N, SD 125) than screws (842 N, SD 140) and sutures (480 N SD 101) (P<0.01). The difference between screws and sutures was also significant (P<0.01).


CONCLUSIONS
Tension banding and two cancellous screws provided the strongest fixation for isolated fractures of the greater tuberosity.
Braunstein
V
V
Department of Surgery, Klinikum Innenstadt, Ludwig-Maximilians-Universitaet Muenchen, Muenchen, Germany. volker.braunstein@aofoundation.org
Wiedemann
E
E
Plitz
W
W
Muensterer
O J
OJ
Mutschler
W
W
Hinterwimmer
S
S
D000328:Adult; D001696:Biomechanical Phenomena; D001863:Bone Screws; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D006810:Humeral Fractures / Q000503:physiopathology* / Q000601:surgery*; D013536:Suture Techniques