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“Normal” Prevertebral Soft Tissue Swelling Following Elective Anterior Cervical Decompression and Fusion

Introduction Prevertebral soft tissue swelling (PSTS) has been evaluated in the setting of traumatic cervical spine injuries. However, no study to date has quantified the PSTS following elective anterior cervical decompression and fusion or the time course to resolution of that swelling. Methods From May 2002 to May 2005 the senior author performed 193 elective 1- or 2-level anterior cervical decompression and fusions. Patients who underwent corpectomies and anterior cervical fusions for trauma or tumor were excluded. Preoperative, 2-week postoperative and 6-week postoperative radiographs were available on 100 patients. The prevertebral soft tissue stripe was measured on the neutral lateral radiographs for the 3 time points. The mean swelling (mm) for each time point was calculated and stratified by cervical level. Repeated measures analysis of variance with the Tukey-Kramer multiple comparisons test was used to compare the measured swelling at the various time points. Results The average PSTS was calculated for each cervical level, for each of the 3 time points, preoperative, 2- and 6-week postoperative. There was a significant increase in PSTS between the preoperative and 2-week postoperative measurements at all levels. There is a significant decrease in PSTS between 2- and 6-week postoperatively at all cervical levels. There is no significant change in PSTS at C2, C3, and C5, when comparing the preoperative and 6-week postoperative measurements. There is significant PSTS at C4, C6, and C7, when comparing preoperative and 6-week postoperative measurements. Conclusions The “normal” range for PSTS at 2 weeks and at 6 weeks after elective 1- and 2- level anterior cervical decompression and fusions is described. Our data demonstrates that edema persists at the 2-week follow-up. By 6 weeks postoperative, the increased PSTS has greatly dissipated.