C7 Pedicle vs. Lateral Mass Screws in Cervical Spondylotic Myelopathy: A Retrospective Analysis of Cervical Alignment Parameters

Abstract

Cervical spondylotic myelopathy (CSM) frequently requires surgical intervention at C7, with the choice between pedicle and lateral mass screws influencing outcomes. Pedicle screws offer superior biomechanical stability but carry higher neurovascular risks, while lateral mass screws are safer but less stable. Limited data compare these techniques in CSM treatment, particularly without O-arm navigation. To compare the safety, efficacy, and spinal alignment outcomes of C7 pedicle screws versus lateral mass screws in CSM patients, especially in settings lacking advanced imaging technologies. This retrospective cohort study analyzed 23 patients (13 with lateral mass screws, 10 with pedicle screws) who underwent posterior fusion surgery for CSM between 2013 and 2022. Preoperative and postoperative CT scans and a minimum one-year follow-up were required. Radiological parameters, including C2 slope, T1 slope, C2-7 Cobb angle, and sagittal vertical axis (SVA), were assessed, along with complications such as screw loosening, breakage, and revision surgeries. No significant differences were found between the two groups in screw loosening (69.2% vs. 60%), breakage (7% vs. 20%), or distal junctional kyphosis rates (7.7% vs. 0%). Both groups demonstrated similar improvements in spinal alignment parameters at postoperative and one-year follow-ups. One patient in the pedicle group required revision for a major foraminal breach, while three patients in the lateral mass group underwent revision for proximal junctional kyphosis. Both pedicle and lateral mass screws provided comparable safety, efficacy, and alignment outcomes at C7 in CSM patients. The choice of screw type should depend on patient anatomy, surgeon preference, and the availability of imaging technology.

Keywords

• Cervical Vertebrae
• Bone Screws
• Spinal Fusion
• Tomography

References

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