A biomechanical comparison of fixed angle locking compression plate osteosynthesis and cement augmented screw osteosynthesis in the management of intra articular calcaneal fractures.
OBJECTIVE
The purpose of this study was to investigate whether cement-augmented screw osteosynthesis results in stability comparable to conventional fixed-angle locking plate osteosynthesis using cadaveric bones to model a Sanders type 2B fracture.


METHODS
Seven pairs of fresh frozen human calcanei and the corresponding tali were used. The specimens were assigned pairwise to two study groups in a randomised manner. In order to determine the initial quasi-static stiffness of the bone-implant construct, testing commenced with quasi-static compression ramp loading; subsequently, sinusoidal cyclic compression loading at 2 Hz was performed until construct failure occurred. Initial dynamic stiffness (cycle 1), range of motion (ROM), cycles to failure and load to failure were determined from the machine data during the cyclic test. In addition, at 250-cycle intervals, Böhler's angle and the critical angle of Gissane were determined on mediolateral X-rays shot with a triggered C-arm; 5° angle flattening was arbitrarily defined as a failure criterion.


RESULTS
Bone mineral density was normally distributed without significant differences between the groups. The augmented screw osteosynthesis resulted in higher stiffness values compared to the fixed-angle locking plate osteosynthesis. The fracture fragment motion in the locking plate group was significantly higher compared to the group with augmented screw osteosynthesis.


CONCLUSIONS
The results of this study indicate that in our selected test set-up augmented screw osteosynthesis was significantly superior to the conventional fixed-angle locking plate osteosynthesis with respect to primary stability and ROM during cyclic testing.
Klinik für Unfall-, Hand-, und Wiederherstellungschirurgie, Friedrich-Schiller-Universität, Jena, Germany, sascha.rausch@med.uni-jena.de.
Sascha
S
Rausch
Kajetan
K
Klos
Uwe
U
Wolf
Marc
M
Gras
Paul
P
Simons
Steffen
S
Brodt
Markus
M
Windolf
Boyko
B
Gueorguiev
D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001843:Bone Cements; D015519:Bone Density; D001860:Bone Plates; D001863:Bone Screws; D002102:Cadaver; D002111:Calcaneus / Q000293:injuries* / Q000601:surgery; D005260:Female; D033023:Foot Joints / Q000601:surgery; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods*; D050723:Fractures, Bone / Q000601:surgery*; D006801:Humans; D007593:Joint Instability / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D016896:Treatment Outcome
D001843:Bone Cements