The Impact of Lateral Mass Versus Pedicle Screws at C7 in C3-T1 Posterior Cervical Decompression and Fusion on Postsurgical Outcomes

Abstract

Study design: Retrospective cohort.

Objective: To evaluate surgical outcomes and opioid consumption among patients undergoing a C3-T1 posterior cervical decompression and fusion (PCDF) with lateral mass or pedicle screw fixation at C7.

Background: Biomechanical work has suggested that junctional pedicle screws provide more robust fixation during cervicothoracic fixation at the expense of increased technical risk compared with lateral mass screws. However, minimal data exist directly comparing these 2 hardware options.

Methods: Adult patients who underwent primary C3-T1 PCDF (2017-2022) with C7 lateral mass versus pedicle screw fixation were compared. Patient demographics, surgical characteristics, and surgical outcomes were collected. Outpatient opioid utilization and morphine milligram equivalents (MMEs) from 1-year preoperatively to 1-year postoperatively were obtained from Pennsylvania Prescription Drug Monitoring Program. In-hospital MME data were also collected.

Results: Thirty patients received lateral mass fixation, and 50 patients received pedicle screw fixation at C7. These groups were demographically similar, with similar average length of follow-up between the lateral mass (748±364 d) and pedicle screw (853±402 d, P=0.28) groups. Despite requiring a greater number of decompressed levels (4.17 vs. 3.74, P=0.002), cut-to-close time was shorter for the lateral mass group compared with the pedicle screw group (168±37.6 vs. 191±41.3 min, P=0.015). However, both groups were similar regarding surgical outcomes and preoperative and 1-year postoperative opioid consumption.

Conclusions: Despite a greater number of decompressed levels among the lateral mass group, these patients experienced a shorter average operative time during C3-T1 PCDF. However, short-term surgical outcomes and opioid consumption up to a year postoperatively were similar between groups. Thus, there does not appear to be short-term safety or pain drawbacks to C7 pedicle screws that would justify the decreased biomechanical advantages of lateral mass screws.

Keywords: PCDF; cervicothoracic junction; lateral mass screw; pedicle screw; posterior cervical decompression and fusion.