OBJECTIVE: To compare the biomechanical performance of a cephalomedullary nail (CMN), a proximal femoral locking plate, and a 95° angled blade plate in a comminuted subtrochanteric fracture model. METHODS: A comminuted subtrochanteric femoral fracture model was created with a 2-cm gap below the lesser trochanter in 15 pairs of human cadaveric femora confirmed to be nonosteoporotic. The femora were randomized to treatment with one of the previously mentioned 3 devices. Each was tested under incrementally increasing cyclic load up to 90,000 cycles from 50% to 250% of body weight to simulate progressive weight bearing during 3 months of an average 700-N (approximately, 70 kg or 150 lb) person. Force, number of cycles, and total load sustained to reach 10 mm of displacement were compared. Failure modes were also noted. RESULTS: The CMN construct withstood significantly more cycles, failed at a significantly higher force, and withstood a significantly greater load than either of the plate constructs (P < 0.001). Varus collapse was significantly lower in the CMN construct (P < 0.0001). Modes of failure differed among implant-bone constructs with damage to the femoral head through implant cutout in 5 of 10 blade plate specimens and 2 of 10 CMN specimens, whereas no damage to the femoral head bone was observed in any of the locking plate constructs. CONCLUSIONS: The CMN construct was biomechanically superior to either the locking plate or 95° blade plate constructs. The locking plate construct was biomechanically equivalent to the blade plate construct.
OBJECTIVE: To compare the biomechanical performance of a cephalomedullary nail (CMN), a proximal femoral locking plate, and a 95° angled blade plate in a comminuted subtrochanteric fracture model. METHODS: A comminuted subtrochanteric femoral fracture model was created with a 2-cm gap below the lesser trochanter in 15 pairs of human cadaveric femora confirmed to be nonosteoporotic. The femora were randomized to treatment with one of the previously mentioned 3 devices. Each was tested under incrementally increasing cyclic load up to 90,000 cycles from 50% to 250% of body weight to simulate progressive weight bearing during 3 months of an average 700-N (approximately, 70 kg or 150 lb) person. Force, number of cycles, and total load sustained to reach 10 mm of displacement were compared. Failure modes were also noted. RESULTS: The CMN construct withstood significantly more cycles, failed at a significantly higher force, and withstood a significantly greater load than either of the plate constructs (P < 0.001). Varus collapse was significantly lower in the CMN construct (P < 0.0001). Modes of failure differed among implant-bone constructs with damage to the femoral head through implant cutout in 5 of 10 blade plate specimens and 2 of 10 CMN specimens, whereas no damage to the femoral head bone was observed in any of the locking plate constructs. CONCLUSIONS: The CMN construct was biomechanically superior to either the locking plate or 95° blade plate constructs. The locking plate construct was biomechanically equivalent to the blade plate construct.
Authors: Joseph J Ruzbarsky; Ishaan Swarup; Matthew R Garner; Kathleen N Meyers; Folorunsho Edobor-Osula; Roger F Widmann; David M Scher Journal: HSS J Date: 2019-03-26
Authors: Korhan Ozkan; İsmail Türkmen; Adem Sahin; Yavuz Yildiz; Selim Erturk; Mehmet Salih Soylemez Journal: Indian J Orthop Date: 2015 May-Jun Impact factor: 1.251