Holding power of orthopedic screws in the large metacarpal and metatarsal bones of calves

Blikslager, A.T.; Bowman, K.F.; Abrams, C.F. Jr; Seaboch, T.R.; Hunt, E.L.

Holding power of orthopedic screws in the large metacarpal and metatarsal bones of calves

1994

Blikslager, A.T. | Bowman, K.F. | Abrams, C.F. Jr | Seaboch, T.R. | Hunt, E.L.

Holding power was determined for various orthopedic screws in bones of calves. Holding power was defined as maximal tensile force required to remove a screw divided by thickness of bone engaged by the screw (kN/mm). Comparative pull-out tests were performed, using pairs of large metacarpal or metatarsal bones from calves aged 3 to 14 days. Comparisons were made of the holding power of 6.5-mm fully threaded cancellous screws and 5.5-mm cortical screws in the proximal and distal metaphyses, and of 4.5-mm and 5.5-mm cortical screws in the diaphysis. Sixteen repetitions of each comparative trial were performed. There was no statistically significant difference in the holding power of 4.5- and 5.5-mm cortical screws in the diaphysis. There was no significant difference in the holding power of 5.5-mm cortical and 6.5-mm fully threaded cancellous screws in the proximal metaphysis. In the distal metaphysis, 6.5-nu-n fully threaded cancellous screws had significantly (P < 0.001) greater holding power than did 5.5-mm cortical screws. There was no significant difference between the mean holding power of 5.5-mm cortical screws in the proximal metaphysis and 5.5-mm cortical screws in the distal metaphysis. There was significantly (P < 0.01) greater mean holding power of 6.5-mm cortical, fully threaded cancellous screws in the distal metaphysis, compared with the proximal metaphysis.

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