Augmentation of XXXX Healing Using Soft Callus.

@entity35 @entity245 @entity174
OBJECTIVES: This study sought to investigate the effect of soft callus removal and reapplication in a @entity35 closed femur @entity174 model. We hypothesized that removing soft callus will impair @entity174 healing, whereas reapplication will facilitate healing. METHODS: A closed midshaft femur @entity174 was created in 78 @entity35 and stabilized with an intramedullary wire. Seven days later, @entity35 were equally divided and @entity174 surgically exposed. In the control group, no callus was removed, whereas in the callus removal group CR(-) group, the callus was removed and in the callus replaced group CR(+), callus was removed and replaced. Half of the @entity35 were killed at 4 and 7 weeks. @entity174 healing was graded with radiographs and callus volume measured with micro-CT. Mechanical torsion properties were measured, and histologic analysis was conducted. RESULTS: At both end points, evidence of @entity245 was found on radiographs and micro-CT in CR(-) @entity35 (P = 0.0001), whereas CR(+) @entity35 showed normal @entity174 healing compared with controls. The normalized callus volume was similar in all groups at both end points. At 7 weeks, the maximum stiffness in CR(-) @entity35 was 68% less than control (P = 0.0001). Stiffness increased 55% in CR(+) @entity35 from CR(-) @entity35 (P = 0.0017). Histology supported our findings with complete endochondral ossification in CR(+) @entity35 but wide areas of hyaline cartilage in CR(-) @entity35 at 7 weeks. CONCLUSIONS: Removal of soft callus in a @entity35 model delays @entity174 healing at early and late time points, whereas replacement mitigates these negative consequences. Replacing the soft callus should be considered in all osteosynthesis procedures.
