Intrinsic Vertebral Markers for Spinal Level Localization in Anterior Cervical Spine Surgery: A Preliminary Report

ABSTRACT

STUDY DESIGN: Prospective clinical study. PURPOSE: To observe the usefulness of anterior cervical osteophytes as intrinsic markers for spinal level localization (SLL) during sub-axial cervical spinal surgery via the anterior approach. OVERVIEW OF LITERATURE Various landmarks, such as the mandibular angle, hyoid bone, thyroid cartilage, first cricoid ring, and C6 carotid tubercle, are used for gross cervical SLL; however, none are used during cervical spinal surgery via the anterior approach. We present our preliminary assessment of SLL over anterior vertebral surfaces (i.e., intrinsic markers) in 48 consecutive cases of anterior cervical spinal surgeries for the disc-osteophyte complex (DOC) in degenerative diseases and granulation or tumor tissue associated with infectious or neoplastic diseases, respectively, at an ill-equipped center. METHODS: This prospective study on patients undergoing anterior cervical surgery for various sub-axial cervical spinal pathologies aimed to evaluate the feasibility and accuracy of SLL via intraoperative palpation of disease-related morphological changes on anterior vertebral surfaces visible on preoperative midline sagittal T1/2-weighted magnetic resonance images. RESULTS: During a 3-year period, 48 patients (38 males,10 females; average age, 43.58 years) who underwent surgery via the anterior approach for various sub-axial cervical spinal pathologies, including degenerative disease (n= 42), tubercular infection (Pott's disease; n=3), traumatic prolapsed disc (n=2), and a metastatic lesion from thyroid carcinoma (n=1), comprised the study group. Intrinsic marker palpation yielded accurate SLL in 79% of patients (n=38). Among those with degenerative diseases (n=42), intrinsic marker palpation yielded accurate SLL in 76% of patients (n=32). CONCLUSIONS: Intrinsic marker palpation is an attractive potential adjunct for SLL during cervical spinal surgeries via the anterior approach in well-selected patients at ill-equipped centers (e.g., those found in developing countries). This technique may prove helpful when radiographic visualization is occasionally inadequate.