Anton Jorgensen

Sentinel Events in Lumbar Spine Surgery.

Study Design. Retrospective national database analysis. Objective. A national population-based database was queried to investigate the incidence and perioperative outcomes associated with sentinel events in lumbar spine surgery. Summary of Background Data. Sentinel events in lumbar spine surgery can have significant medical, social, economic, and legal implications. The incidence and perioperative outcomes associated with these events have not been well characterized. Methods. Data from the Nationwide Inpatient Sample was queried from 2002 to 2011. Patients who underwent lumbar spinal surgery were identified. Sentinel events including bowel or peritoneal injury, vascular injury, nerve injury, retention of foreign objects, and wrong-site surgery were identified. Patient demographics, comorbidities (Charlson Comorbidity Index), length of stay, total costs, and perioperative outcomes were assessed. The risk for mortality associated with each sentinel event was calculated using a 95% confidence interval. Statistical analysis was performed with SPSS version 20 and a P value of 0.001 or less denoted significance. Results. A total of 543,146 lumbar spine surgical procedures were recorded from 2002 to 2011, of which 414 (0.8 per 1000 cases) incurred sentinel events. Wrong-site surgical procedures were the most common sentinel events with an incidence of 0.3 per 1000 cases. The incidences for bowel or peritoneal injury, vascular injury, nerve injury, and retention of foreign objects, were 0.06, 0.2, 0.2, and 0.1 per 1000 cases, respectively. There were no significant differences in the mean age (55.9 vs. 56.0, P = 0.911) or comorbidity burden (2.58 vs. 2.63, P = 0.553) between the 2 cohorts. The sentinel event cohort incurred a longer hospitalization, greater costs, and a greater incidence of in-hospital complications, and mortality. Patients with a bowel or peritoneal injury, vascular injury, and wrong-site surgery demonstrated a greater risk of mortality relative to unaffected patients. Conclusion. This Nationwide Inpatient Sample analysis demonstrates that sentinel events are associated with a significant increase in hospital resource utilization and worsened postoperative outcomes including death. This study demonstrates the financial and medical burden associated with sentinel events in lumbar spine surgery. Level of Evidence: 4

Neuroforaminal Bone Growth Following Minimally Invasive Transforaminal Lumbar Interbody Fusion With BMP: A Computed Tomographic Analysis.

Study Design: Computed tomographic analysis. Objective: To identify radiographic patterns of symptomatic neuroforaminal bone growth (NFB) in patients who have undergone a single-level minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) augmented with bone morphogenetic proteins (BMP) utilizing computed tomography (CT). Summary of Background Data: BMP induces osteoblast differentiation leading to new bone formation. The association of BMP utilization and heterotopic bone formation after an MIS-TLIF has been described. However, studies have been limited in their patient population and details regarding diagnosis and treatment of NFB. Materials and Methods: Postoperative CT scans of the symptomatic and asymptomatic patients were analyzed to identify patterns of heterotopic bone growth on axial and sagittal views. The area of bone growth at the disk level, lateral recess, adjacent foramen, and retrovertebral area were measured. Mann-Whitney U test was used to compare the areas of bone growth between cohorts. Results: Postoperative CT images between 18 symptomatic and 13 asymptomatic patients were compared. On axial views, the symptomatic patients demonstrated greater areas of bone growth at the disk level (164.0±92.4 vs. 77.0±104.9 mm2), and lateral recess (69.6±70.5 and 5.9±12.5 mm2) as well as in the total cross-sectional area (290.3±162.1 vs. 119.4±115.6 mm2). On sagittal imaging, the mean bone growth at the subarticular level (148.7±185.1 vs. 35.8±37.4 mm2) and the total cross-sectional area (298.4±324.4 vs. 85.8±76.3 mm2) were greater in symptomatic patients (P<0.01). Amount of BMP utilized and operative levels were no different between cohorts. Conclusions: The findings of the present study suggest that an anatomic association exists between recalcitrant postoperative radiculopathy and NFB following an MIS-TLIF with BMP. Increased total bone growth as measured on serial axial and sagittal sections was associated with postoperative radiculopathy. The association between radiculopathy and the extension of BMP-induced bone growth toward the traversing nerve root appeared the most significant.