RESUMO
OBJECTIVE: The challenges of posterior cervical fusions (PCFs) at the cervicothoracic junction (CTJ) are widely known, including the development of adjacent-segment disease by stopping fusions at C7. One solution has been to cross the CTJ (T1/T2) rather than stopping at C7. This approach may have undue consequences, including increased reoperations for symptomatic nonunion (operative nonunion). The authors sought to investigate if there is a difference in operative nonunion in PCFs that stop at C7 versus T1/T2. METHODS: A retrospective analysis identified patients from the authors' spine registry (Kaiser Permanente) who underwent PCFs with caudal fusion levels at C7 and T1/T2. Demographics, diagnoses, operative times, lengths of stay, and reoperations were extracted from the registry. Operative nonunion was adjudicated via chart review. Patients were followed until validated operative nonunion, membership termination, death, or end of study (March 31, 2020). Descriptive statistics and 2-year crude incidence rates and 95% confidence intervals for operative nonunion for PCFs stopping at C7 or T1/T2 were reported. Time-dependent crude and adjusted multivariable Cox proportional hazards models were used to evaluate operative nonunion rates. RESULTS: The authors identified 875 patients with PCFs (beginning at C3, C4, C5, or C6) stopping at either C7 (n = 470) or T1/T2 (n = 405) with a mean follow-up time of 4.6 ± 3.3 years and a mean time to operative nonunion of 0.9 ± 0.6 years. There were 17 operative nonunions, and, after adjustment for age at surgery and smoking status, the cumulative incidence rates were similar between constructs stopping at C7 and those that extended to T1/T2 (C7: 1.91% [95% CI 0.88%-3.60%]; T1/T2: 1.98% [95% CI 0.86%-3.85%]). In the crude model and model adjusted for age at surgery and smoking status, no difference in risk for constructs extended to T1/T2 compared to those stopping at C7 was found (adjusted HR 1.09 [95% CI 0.42-2.84], p = 0.86). CONCLUSIONS: In one of the largest cohort of patients with PCFs stopping at C7 or T1/T2 with an average follow-up of > 4 years, the authors found no statistically significant difference in reoperation rates for symptomatic nonunion (operative nonunion). This finding shows that there is no added risk of operative nonunion by extending PCFs to T1/T2 or stopping at C7.
RESUMO
OBJECTIVES: To report the incidence of patients with extra-articular posterosuperior acetabular cortical impaction associated with a posterior wall acetabular fracture-dislocation. DESIGN: Retrospective case series. SETTING: Regional Level 1 trauma center. PATIENTS/PARTICIPANTS: Ninety-seven patients who sustained an isolated posterior wall acetabular fracture-dislocation from July 2007 until July 2017. INTERVENTION: The medical record and the computed tomography (CT) scan of the abdomen and pelvis were reviewed including axial, coronal, and sagittal reconstruction images and 3D surface renderings. MAIN OUTCOME MEASUREMENTS: Each pelvic CT scan was evaluated for impaction of the extra-articular posterosuperior acetabular cortical surface associated with posterior wall acetabular fracture-dislocations. The reduction accuracy was assessed for each patient with cortical impaction using postoperative CT scans. The final attending radiology report was reviewed to see whether the cortical impaction was noted. RESULTS: Four of the 99 patients (4.12%) had identifiable areas of cortical impaction on preoperative CT imaging. Reduction accuracy demonstrated 1 anatomical reduction, 2 imperfect reductions, and 1 poor reduction. The final attending radiologist report did not comment on any patient with cortical impaction. CONCLUSIONS: Our study demonstrates that a small number of patients sustain cortical impaction of the posterosuperior acetabular cortical surface along with their posterior wall acetabular fracture-dislocation. Although uncommon, preoperative imaging should be scrutinized to identify this clinical entity. As part of the preoperative plan, the surgeon can anticipate the cortex available for reduction verification and whether any additional steps or altered surgical approaches are needed to achieve an anatomical reduction. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.