Khaled Aboushaala

Primary Versus Revision Single-level Minimally Invasive Lumbar Discectomy: Analysis of Clinical Outcomes and Narcotic Utilization.

Study Design. Retrospective cohort analysis of a prospectively maintained registry. Objective. To compare the intraoperative variables, surgical outcomes, and narcotic utilization between primary and revision 1-level minimally invasive (MIS) lumbar discectomies. Summary of Background Data. Revision spine surgery may be associated with longer procedural time and greater soft tissue disruption. Few studies have analyzed the surgical outcomes and narcotic utilization associated with MIS revision lumbar discectomies. Methods. A retrospective analysis of 227 consecutive cases of MIS 1-level lumbar discectomy for degenerative spinal pathology between 2009 and 2014 by a single surgeon was performed. Patients were stratified into primary and revision cohorts. Demographics, comorbidity, intraoperative parameters, peri- and postoperative outcomes, and reoperations were assessed. Postoperative narcotic utilization was compared between cohorts. Statistical analyses were performed using Student t-test and Pearson &khgr;2 test. A P < 0.05 denoted statistical significance. Results. Of the 227 cases included, 186 patients (81.9%) and 41 patients (18.1%) were included in the primary and revision cohorts, respectively. Demographics, comorbidity, smoking status, preoperative visual analogue scale (VAS) scores, and estimated blood loss did not differ between cohorts. However, the revision cohort demonstrated a longer procedural time, increased length of hospitalization, and higher postoperative narcotic utilization. Although not statistically significant, revision patients trended toward higher 6-week postoperative VAS scores and reherniation rates. In addition, revision patients were more likely to undergo subsequent lumbar fusion than primary patients. Conclusion. The findings suggest that revision MIS lumbar discectomy may be associated with increased procedural time, increased length of hospitalization, and increased postoperative narcotic utilization. Whereas revision patients trended toward higher postoperative VAS scores at 6 weeks, both cohorts demonstrated similar pain levels at final follow-up. Finally, revision patients may be at a greater risk of reherniation and subsequent reoperation. Further studies are warranted to characterize the independent risk factors for a revision lumbar discectomy. Level of Evidence: 3

Comparison of Surgical Outcomes, Narcotics Utilization, and Costs After an Anterior Cervical Discectomy and Fusion: Stand-alone Cage Versus Anterior Plating.

Study Design: Retrospective cohort analysis of a prospectively maintained registry. Objective: To compare the surgical outcomes, narcotic utilization, and costs between a stand-alone (SA) cage and anterior plating (AP) with an interbody device for 1-level anterior cervical discectomy and fusion (ACDF). Background Data: ACDF with a SA cage has gained popularity as a potential alternative to anterior cervical plating. Few studies have compared the surgical outcomes, narcotic utilization, and costs of ACDF utilizing a SA cage versus AP with an interbody device. Methods: Patients who underwent a primary 1-level ACDF for degenerative spinal pathology between 2010 and 2013 were analyzed. Patients were stratified on the basis of the type of implant system (SA cage vs. AP) and assessed with regard to demographics, comorbidities, smoking, visual analogue scale (VAS) scores (preoperative/postoperative), procedural time, estimated blood loss (EBL), length of hospitalization, complications, reoperations, narcotic consumption, and total costs. Statistical analysis was performed with independent sample T tests for continuous variables and &khgr;2 analysis for categorical data. An &agr; level of <0.05 denoted statistical significance. Results: Of the 93 patients included, 52 (55.9%) underwent an ACDF with a SA cage system. Patient demographics, comorbidity burden, body mass index, smoking status, and preoperative VAS score were similar between cohorts. The SA cohort incurred a significantly lower EBL (P<0.001) than the AP cohort. However, none required a transfusion and the procedural time, length of hospitalization, postoperative VAS score, complication rates, 1-year arthrodesis rate, and reoperation rates were similar between cohorts. Postoperative narcotics consumption and total costs were also similar between groups. Conclusions: Our findings suggest that the SA cage may be associated with a significantly lower EBL, which may not be clinically relevant. Perioperative outcomes, complications, reoperation rates, narcotics consumption in the immediate postoperative period, and total costs may be similar regardless of the instrumentation utilized in a 1-level ACDF.

Postoperative Narcotic Consumption in Workmanʼs Compensation Patients Following a Minimally Invasive Transforaminal Lumbar Interbody Fusion

Study Design. Retrospective cohort analysis of a prospective registry. Objective. To assess the differences in perioperative narcotic consumption between Workmans compensation (WC) and non-Workmans compensation (non-WC) patients after a single-level minimally invasive transforaminal lumbar interbody fusion. Summary of Background Data. There is concern regarding the potential overutilization of opioid pain medication in WC patients. However, the impact of WC status on perioperative narcotic consumption after lumbar spine procedures has not been previously reported. Methods. A cohort of patients who underwent primary 1-level minimally invasive transforaminal lumbar interbody fusion procedures for degenerative spinal pathology between 2007 and 2013 was retrospectively analyzed using a prospectively collected registry. First, preoperative and perioperative characteristics were compared between WC and non-WC patients. Second, mean oral morphine equivalent was compared between WC and non-WC patients with adjustment for any preoperative or perioperative differences between cohorts. Results. A total of 136 single-level, primary minimally invasive-transforaminal lumbar interbody fusion procedures were included in the analysis, of which 46 (33.8%) were WC patients. WC patients were younger (47.8 ± 11.2 vs. 57.9 ± 10.4 yr; P < 0.001) and had a lower comorbidity burden (Charlson Comorbidity Index: 1.85 ± 1.30 vs. 3.42 ± 2.07; P < 0.001) than non-WC patients. The distribution of ethnicity differed between WC and non-WC patients (P = 0.002). WC patients incurred longer procedural times (135.2 ± 52.2 vs. 118.9 ± 33.7 min; P < 0.05). However, the estimated blood loss, length of hospital stay, and day of discharge were no different between WC and non-WC patients. Mean oral morphine equivalent consumption did not differ between WC and non-WC patients after adjustment for differences in age, ethnicity, Charlson Comorbidity Index, and procedural time between cohorts. Conclusion. Despite concerns for greater opioid use in the WC population, this analysis demonstrated similar total narcotic consumption between WC and non-WC patients during the immediate postoperative period. Long-term studies are warranted to assess whether this similarity in regard to perioperative narcotic consumption persists beyond the immediate postoperative period. Level of Evidence: 3

Functional Capacity Evaluation Following Spinal Fusion Surgery.

Study Design. Retrospective review of prospectively collected data. Objective. The aim of the study was to characterize outcomes of functional capacity evaluations (FCEs) amongst patients undergoing spinal fusion surgery. Summary of Background Data. Injured workers often undergo an FCE upon reaching maximal medical improvement following surgery. To date, few studies have examined the results of FCEs following spinal fusion. Methods. Patients undergoing an FCE following a minimally invasive transforaminal lumbar interbody fusion (TLIF) or anterior cervical discectomy and fusion (ACDF) were retrospectively identified. Based upon the FCE report, each patients job-related preoperative physical requirement and postoperative work capability was categorized as light, medium, or heavy. Patients were characterized as being able to meet their preoperative job requirement if their FCE-determined capability was greater than or equal to their preoperative job requirement. Patient characteristics were tested for association with meeting preoperative job requirement using bivariate and multivariate regression. Results. A total of 173 patients were identified: 71 (41.0%) and 102 (59.0%) underwent TLIF and ACDF, respectively. Of the 71 TLIF and 102 ACDF patients, 41 (58%) and 50 (49%) had light postoperative capabilities, 18 (25%) and 38 (37%) as medium, and 12 (17%) and 14 (14%) as heavy, respectively. Postoperatively, 26 (37%) of TLIF and 55 (54%) of ACDF patients were categorized as meeting their preoperative job requirement. Independent predictors of meeting preoperative job requirement following TLIF (P =0.002) and ACDF (P = 0.037) were lower preoperative job requirement, and younger age for ACDF (P < 0.001). Conclusion. Only one in five patients undergoing spinal fusion surgery for occupational injuries is able to perform heavy-duty work postoperatively. Similarly, approximately half of patients are able to perform medium-duty work. Moreover, a majority of patients are unable to return to their preoperative occupational responsibilities. These findings can be used to council patients regarding their likelihood of meeting postoperative work capacity. Level of Evidence: 3

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.