Mechanical complication patterns following cervical and cervicothoracic junction en bloc spondylectomy of primary spinal tumors: a single-institution decade of experience.

OBJECTIVE: The aim of this study was to characterize reconstruction strategies, mechanical failure modes, and risk signals after cervical/cervicothoracic junction (CTJ) en bloc spondylectomy at a high-volume tumor center. METHODS: A single-institution retrospective cohort (2015-2025) of consecutive cervical/CTJ primary tumors treated with en bloc spondylectomy and circumferential reconstruction was performed. Demographics, pathology, construct details, bone quality by Hounsfield units (HUs), and oncological therapies were abstracted. The primary endpoint was instrumentation failure, including any mechanical event prompting or necessitating revision. Univariate analysis was conducted. RESULTS: Twenty patients (mean age 49.1 ± 15.3 years; 55% male) were included; 50% of tumors were chordomas, 15% were chondrosarcomas, and 35% were other tumors. Anterior column reconstruction was performed using a titanium cage in 85% of patients; posterior reconstruction was performed using 2 rods in 75% of patients (3.5-mm rods in 65% patients). Cobalt-chromium rods were used in 5% of patients. Instrumentation failure occurred in 3 (15%) of the 20 patients at 4-44 months (median nonfailure follow-up 30 months, range 1-96 months; failure follow-up 60 months, range 44-94 months). Two of the failures were anterior column events (cage migration or delayed visceral erosion) and one was a posterior rod fracture. Patients with failure more often had smaller (3.5 mm) 2-rod constructs and fewer levels instrumented above the resection; cobalt-chromium rod use was more common among failures (33.3% vs 0%, p = 0.015). Thirty-day readmission was higher in patients with failure (100% vs 17.6%, p = 0.004). HU values trended toward lower rates of failures. CONCLUSIONS: Mechanical complications occurred in 15% of cervical/CTJ spondylectomies, with a notable proportion involving anterior column failure. Although underpowered for definitive predictors, this exploratory analysis identified several risk signals: limited proximal fixation, small-diameter 2-rod constructs, and cobalt-chromium rod usage that may inform CTJ-specific reconstruction strategies. These findings support exploring the impact of robust proximal fixation, biologically supported anterior reconstruction, bone-health optimization, and long-term surveillance on mechanical complications in CTJ en bloc spondylectomy of primary spinal tumors.