Abstract
Objectives
To investigate the amount of interfragmentary compression obtained in a transverse tibia fracture model with backslapping alone (BS) versus the intramedullary nail’s dynamic internal compression (IC) mechanism and if that compression is maintained after loading.
Methods
A transverse diaphyseal tibia synthetic fracture model was used. Specimens were allocated to four groups (n=5/group) that received one of two intramedullary nails (A or B) and obtained compression either with the IC device or with BS alone. Specimens underwent sinusoidal loading for 135,000 cycles of 700N @3Hz to simulate three months of weightbearing. Interfragmentary pressure measurements were measured at initial compression, procedure completion (pre-cycling) and after loading (post-cycling). Compression at each stage was compared between BS and IC groups as well as between stages. Outcomes were also compared between Nails A and B.
Results
There was significantly greater initial (1097N vs 167N, p
Conclusions
Intramedullary IC devices generated and maintained greater interfragmentary fracture compression than traditional BS techniques alone. However, some compressive force was lost after loading regardless of compression technique utilized. Differences in compressive force were observed between nail manufacturers with both techniques, which may suggest that nail geometry and instrumentation may contribute to fracture compression.
Level of Evidence
V