Study Design: Retrospective cohort study. Objective: Studies investigating the impact of interbody subsidence in ACDF suggest a correlation between subsidence and worse radiographic and patient-reported outcomes. The purpose of this study was to assess whether allograft subsidence assessed on CT is associated with worse cervical alignment. Methods: We performed a retrospective review of a prospective cohort of patients undergoing 1 to 3 level ACDF. Cervical alignment was assessed on standing radiographs performed preoperatively, less than 2 months postoperatively, and greater than 6 months postoperatively. Allograft subsidence was assessed on CT scan performed at least 6 months postoperatively. Patients with at least 1 level demonstrating greater than 4mm of cage subsidence were classified as severe subsidence. Student’s t-test was used to compare all means between groups. Results: We identified 66 patients for inclusion, including 56 patients with non-severe subsidence and 10 patients with severe subsidence. For the entire cohort, there was a significant increase in C2-7 Lordosis (p = 0.005) and Segmental Lordosis (p < 0.00 001) from preoperative to early postoperative. On comparison of severely and non-severely subsided levels, severely subsided levels demonstrated a significantly greater loss of segmental lordosis from early to mid-term follow-up than non-severely subsided levels (-4.89 versus -2.59 degrees, p < 0.0001), manifesting as a significantly lower segmental lordosis at >6 months postoperative (0.54 versus 3.82 degrees, p < 0.00 001). There were no significant differences in global cervical alignment parameters between patients with severe and non-severe subsidence. Conclusions: Severe subsidence is associated with a significant increase in loss of segmental lordosis, but has minimal effect on global cervical alignment parameters.
The Incidence, Risk Factors, and Complications Associated With Surgical Delay in Multilevel Fusion for Adult Spinal Deformity
Study Design: Retrospective database review. Objectives: The incidence and risk factors for surgical delay of multilevel spine fusion for adult spinal deformity (ASD), and the complications corresponding therewith, remain unknown. The objectives of this study are to assess the incidence and risk factors for unexpected delay of elective multilevel spinal fusions on the date of surgery as well as the postoperative complications associated with these delays. Methods: We conducted a retrospective review of the ACS-NSQIP database on patients undergoing elective spinal instrumentation of greater than 7 levels for ASD between the years 2005 and 2015. Preoperative risk factors for delay and postoperative complications were compared between the cohorts of patients with and without surgical delays. Results: Multivariate analysis of 1570 (15.6%) patients identified advanced age, male sex, American Society of Anesthesiologists (ASA) Class 4, and history of smoking as independent risk factors for delay. Patients experiencing surgical delay demonstrated longer operative times, increased intraoperative bleeding, longer hospitalizations, and significantly higher rates of postoperative complications. Patients experiencing delay demonstrated an almost 7-fold increase in mortality rate (3.4% vs 0.5%, P < .001). Conclusions: Delays in elective surgical care for spinal deformity are negatively related to patient outcomes. Advanced age, male sex, increased ASA class, and a history of smoking cigarettes place patients at risk for surgical delay of multilevel spinal fusion. Patients experiencing surgical delay are at higher risk for postoperative complications, including a 7-fold increase in mortality. These findings suggest that ASD surgery should be postponed in patients experiencing a delay, until modifiable risk factors can be medically optimized, and perhaps postponed indefinitely in those with nonmodifiable risk factors.
Surgical Management of Thoracolumbar Burst Fractures
The management of thoracolumbar burst fractures is controversial with no universally accepted treatment algorithm. Several classification and scoring systems have been developed to assist in surgical decision-making. The most widely accepted are the Thoracolumbar Injury Classification and Severity Score (TLICS) and AOSpine Thoracolumbar Injury Classification Score (TL AOSIS) with both systems designed to provide a simple objective scoring criteria to guide the surgical or nonsurgical management of complex injury patterns. When used in the evaluation and treatment of thoracolumbar burst fractures, both of these systems result in safe and consistent patient care. However, there are important differences between the 2 systems, specifically in the evaluation of the complete burst fractures (AOSIS A4) and patients with transient neurological deficits (AOSIS N1). In these circumstances, the AOSpine system may more accurately capture and characterize injury severity, providing the most refined guidance for optimal treatment. With respect to surgical approach, these systems provide a framework for decision-making based on patient neurology and the status of the posterior tension band. Here we propose an operative treatment algorithm based on these fracture characteristics as well as the level of injury.
Higher Paraspinal Muscle Density Effect on Outcomes After Anterior Cervical Discectomy and Fusion
Study Design: Retrospective cohort study. Objectives: Studies in the lumbar spine suggest a correlation between sarcopenia and worse patient outcomes. The purpose of this study was to determine whether paraspinal Goutalier grade of fat degeneration is associated with patient-reported outcomes in patients undergoing anterior cervical discectomy and fusion (ACDF). Methods: We performed a retrospective review of a prospective cohort of patients undergoing 1- to 3-level ACDF at a single institution between the years 2011-2014. We utilized preoperative magnetic resonance images to classify patients into Goutalier grades. Patient-reported outcomes, including Neck Disability Index (NDI), RAND score, and EQ-5D score were collected and analyzed according to patients’ Goutalier grade. Results: We identified 69 patients for inclusion. A total of 29 patients were classified as Goutalier 0-1 (group 1), 29 were Goutalier 1.5-2 (group 2), and 11 were Goutalier 2.5-4.0 (group 3). All Goutalier groups experienced significant improvement in all 3 outcome scores. Average postoperative NDI scores were 25.3 in group 1, 13.9 in group 2, and 25.1 in group 3 ( P = .02). The percentage of patients in each group reporting worse disability after surgery was 17.2%, 3.3%, and 9.1%, respectively ( P = .05). No statistically significant difference was seen between groups in postoperative EQ-5D ( P = .07) or RAND scores ( P > .05). Conclusions: The present study is the first to assess the association between cervical paraspinal muscle Goutalier grade and patient-reported outcomes following ACDF. Based on our study, patients with worse cervical paraspinal degeneration may benefit from improved symptom relief in comparison to patients with a lesser degree of degeneration undergoing ACDF.
A Comparison of Revision Rates and Patient-Reported Outcomes for a 2-Level Posterolateral Fusion Augmented With Single Versus 2-Level Transforaminal Lumbar Interbody Fusion
Study Design: Retrospective, single institution, multisurgeon case control series. Objective: To determine whether there are differences in reoperation rates or outcomes for patients undergoing 2-level posterolateral fusion (PLF) augmented by a transforaminal lumbar interbody fusion (TLIF) at only one of the levels or at both. Methods: A total of 416 patients were identified who underwent 2-level PLF with a TLIF at either one of those levels (n = 183) or at both (n = 233) with greater than 1-year follow-up. Demographic, surgical, radiographic, and clinical data was reviewed for each patient. These included age, sex, race, body mass index, smoking status, Charleston Comorbidity Index, operative time, estimated blood loss, length of stay, and patient-reported outcome measures. Results: Each cohort underwent 24 reoperations. Although the number of overall reoperations was not significantly different ( P > .05), among the reoperation types, there were significantly more reoperations for adjacent segment disease in the 2-level group compared to the 1-level group (19 vs 12, P = .04). There was no difference in reoperation for pseudarthrosis between the groups ( P > .05). Although both groups experienced significant improvements in Oswestry Disability Index ( P < .001) and Short Form–12 health questionnaire ( P < .001), there were no differences between improvements for 1- versus 2-level cohorts. Conclusions: For patients undergoing 2-level PLF in the setting of a TLIF, using a TLIF at one versus both levels does not seem to influence reoperation rates or outcomes. However, reoperation rates for adjacent segment disease are increased in the setting of a 2-level PLF augmented by a 2-level TLIF.
Does Surgically Managed Grade I Degenerative Lumbar Spondylolisthesis Require Fusion?