Sa4.8 Video-assisted interlocking of intramedullary nails

Abstract

either two 6.5mm cancellous, four 3.5mm cortical lag screws or 3.5mmLCP proximal lateral tibia plate, preliminary compression by a reduction clamp (n =5per group). Interfragmentary compressionwas measured by a pressure sensor film after instrumentation. A one-way analysis of variance (ANOVA)with Bonferroni post hoc correctionwas performed for statistical analysis (p <0.05). Results: Two 6.5mm cancellous lag screws achieved significantly higher compression in non-osteoporotic (2.1±0.6MPa) compared to osteoporotic (0.8±0.2MPa, p <0.01) surrogate bone. Using four 3.5mm cortical lag screws, compression was not significantly different in-between the non-osteoporotic (1.7±0.7MPa) and osteoporotic group (1.4±0.5MPa, p = 1.0), but significantly higher compared to locking plate fixation (non-osteoporotic 0.5±0.1MPa, p <0.01; osteoporotic 0.5±0.1MPa, p = 0.03; plate groups p =1.0). Conclusion: The two6.5mmcancellous screw technique is especially suited for young human non-osteoporotic bone, whereas the four 3.5mm cortical screw configuration could also be applied in osteoporotic bone. A certain amount of compression necessary to avoid a plateau widening and maintain reduction was also achieved by angle stable locking plates, if they are preliminary compressed by a reduction clamp.