Deterioration of trabecular bone microarchitecture in the lumbar vertebrae in growing male mice following sciatic neurectomy

Sciatic nerve injury (SNI) can lead to significant bone loss in the lower extremities. However, the effects of SNI on the lumbar vertebrae are controversial. The present study aimed to evaluate the longitudinal effects of SNI on the lumbar vertebrae. Twenty-four 12-week-old male C57BL/6 mice (24.55±0.17 g) were randomly assigned to 3 groups (8 mice each) and underwent unilateral sciatic neurectomy (USN group), bilateral sciatic neurectomy (BSN group), or no surgery (CON group). The third (L3) and fourth (L4) lumbar vertebrae were scanned by in-vivo micro-computed tomography (ìCT) preoperatively and at 14 and 28 days postoperatively. Using μCT images, structural parameters and bone mineralization density distribution of the trabecular bone were analyzed among the 3 groups. In the BSN group, structural and material properties of L3 and L4 worsened after 14 days. Deterioration in the structural properties of L3 was observed at 28 days in the USN group, whereas no changes were observed in L4. These results implied that SNI can cause considerable deterioration in the microarchitecture of trabecular bone in the lumbar vertebrae. However, differences in the magnitude and rate of the deterioration and its onset period are observed between cases of unilateral and bilateral SNI.