Evaluation of 2 cement techniques for augmentation of stripped 1.5 mm screw sites in the distal metaphysis of feline radii.
OBJECTIVE
To evaluate the effect of 2 cement augmentation techniques on pullout strength of 1.5 mm screws placed in stripped 1.5 mm screw sites in the distal metaphysis of feline radii.


METHODS
Experimental study.


METHODS
Feline radii (21 pairs).


METHODS
Treatment groups (n=4) were allocated according to a Latin square design to 4 sites in each pair of radii. Positive and negative controls were a 1.5 mm screw and a screw of the same diameter in a previously stripped screw hole, respectively. Treatment groups were a 1.5 mm screw implanted in a previously stripped screw hole after injection of polymethylmethacrylate (PMMA) or a bioresorbable calcium phosphate cement (CPC, Norian skeletal repair system (SRS)). The ultimate pullout strength was compared between groups.


RESULTS
The mean (+/-SEM) pullout strength of screws augmented with either bone cement was less than that of the positive control group and greater than that of the negative control. Injection of CPC or PMMA before screw implantation increased the pullout strength of the negative control by 86.8+/-22.9% and 104.1+/-32.1%, respectively. Holding power of the positive control screws differed from these 2 groups, and was 274.8+/-39.17% higher than that of the negative control.


CONCLUSIONS
Injection of CPC or PMMA increases but does not restore the holding power of stripped 1.5 mm diameter screws.


CONCLUSIONS
The use of CPC (Norian SRS) augmentation of stripped 1.5 mm diameter screws warrants clinical investigation as it combines biomechanical results similar to PMMA with osteoconduction and resorbability.
Griffon
Dominique J
DJ
Departments of Veterinary Clinical Sciences and Veterinary Biosciences, College of Veterinary Medicine, University of Illinois, 1008 W. Hazelwood Drive, Urbana, IL 61802, USA. dgriffon@uiuc.edu
Stoller
Alex
A
Schaeffer
David J
DJ
Seddighi
Mohamed R
MR
Johnson
Ann L
AL
Kurath
Peter
P
D000818:Animals; D001843:Bone Cements; D001863:Bone Screws / Q000662:veterinary*; D002415:Cats / Q000293:injuries / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000379:methods / Q000662:veterinary*; D011859:Radiography; D011885:Radius Fractures / Q000000981:diagnostic imaging / Q000601:surgery / Q000662:veterinary*; D013718:Tensile Strength
D001843:Bone Cements