[Biomechanical comparison of six different fixation techniques for treatment of metacarpal neck fractures].


Klinik für Unfall- und Wiederherstellungschirurgie, Handchirurgie und Orthopädie, St. Vinzenz-Hospital, Köln, Deutschland. [Email]


OBJECTIVE : The purpose of this study was to evaluate the primary stability of commonly used fixation techniques for metacarpal neck fractures and to compare it with that of an innovative osteosynthesis device: IlluminOss™, the photodynamic bone stabilization system™.
METHODS : Metacarpal neck fractures were created on the second to fifth metacarpal bones of 24 freshly frozen human cadavers using a band saw. Specimens were randomly assigned to one of six groups and treated with (1) K-wire fixation, (2) dorsal plating, (3) external fixation, (4) cross-threaded K‑wire fixation, (5) IlluminOss™ and (6) locked IlluminOss™. In each group 16 specimens each underwent either monocyclic or polycyclic loading protocols.
RESULTS : During monocyclic loading none of the specimens failed prior to a maximum deformation of 3 mm. With intramedullary K‑wire fixation the mean loads were significantly lower than those of the other techniques. Mean loads causing 2 mm deformation with external fixation were significantly lower than those with dorsal plate osteosynthesis. The mean linear stiffness of the K‑wire osteosynthesis was significantly lower than for the other fixation techniques and all methods of external fixation were significantly lower than dorsal plates. There were no significant differences with respect to the linear stiffness between the groups with dorsal plates, fragment fixation system (FFS), IlluminOss™ and locked IlluminOss™. During polycyclic testing the loss of resistance in dorsal plate osteosynthesis was significantly lower than with K‑wire and IlluminOss™ fixation. No significant differences in loss of resistance could be shown between dorsal plate osteosynthesis, external fixation, FFS and locked IlluminOss™.
CONCLUSIONS : In summary, IlluminOss™ can be used as an intramedullary stabilization system for treatment of metacarpal neck fractures. In combination with locking screws the biomechanical characteristics of IlluminOss™ are comparable to the other fixation techniques.


Boxers fracture,Hand,IlluminOss,Metacarpus,Phalangeal,Photodynamic monomer,