Open reduction internal fixation for midline mandibulotomy: lag screws vs plates.

IMPORTANCE

Midline mandibulotomy is a common approach for resection of head and neck oral cavity and oropharyngeal tumors; however, there are limited data available on the outcomes of lag screw vs plate fixation.

OBJECTIVE

To compare outcomes for midline mandibulotomy open reduction and internal fixation using plates vs lag screw technique.

DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study at a tertiary care academic medical center of patients undergoing midline mandibulotomy for head and neck tumor resection over a 6-year period.

INTERVENTIONS

Mandibular fixation using lag screws or plates.

MAIN OUTCOMES AND MEASURES

The medical records and computed tomographic (CT) scans of patients undergoing midline mandibulotomy for head and neck tumor resection over a 6-year period were retrospectively reviewed. The postoperative CT scans were reviewed by a neuroradiologist who graded the fusion site on a scale of 0 to 2 using a 2-pass method. The rates and grades of union were compared, as well as several factors that affect healing, for fixations performed with plates vs lag screws.

RESULTS

Thirty-seven patients were included. The overall rate of radiologic union was 90% (9 out of 10) for lag screw technique and 41% (11 out of 27) for plates (P = .01). The average grade of radiologic union was 1.3 for lag screws and 0.67 for plates (P = .04). Hardware exposure occurred in 4 (15%) of the plate group and fistulae formed in 3 (11%); neither complication occurred in the lag screw group. In univariate analysis, both presence of dentition (odds ratio [OR], 5.50 [95% CI, 1.33-22.73]; P = .02) and plate technique (OR, 13.09 [95% CI, 1.45-11.62]; P = .02) were significantly associated with nonunion. In multivariate analysis, plate technique had an OR of 8.32 (95% CI, 0.85-81.75) for nonunion (P = .07).

CONCLUSIONS AND RELEVANCE

Fixation of midline mandibulotomy with lag screws results in a significantly increased rate of radiologic union compared with plates. Lag screws were also significantly better at achieving radiologic union in patients who underwent postoperative radiation, and the rates of fistula formation and hardware exposure were lower. Thus, lag screw fixation of midline mandibulotomy should be considered an excellent option, especially when patients will undergo postoperative adjuvant therapy and in patients at high risk for wound complications.