Ehsan Tabaraee

Intraoperative cone beam-computed tomography with navigation (O-ARM) versus conventional fluoroscopy (C-ARM): a cadaveric study comparing accuracy, efficiency, and safety for spinal instrumentation.

Study Design. Cadaveric laboratory study. Objective. To compare the accuracy, efficiency, and safety of intraoperative cone beam–computed tomography with navigation (O-ARM) with traditional intraoperative fluoroscopy (C-ARM) for the placement of pedicle screws. Summary of Background Data. Radiation exposure remains a concern with traditional methods of intraoperative imaging in spine surgery. The use of O-ARM has been proposed for more accurate and efficient spinal instrumentation. Understanding radiation imparted to patients and surgeons by O-ARM is important for assessing risks and benefits of this technology, especially in light of evolving indications. Methods. Four surgeons placed 160 pedicle screws on 8 cadavers without deformity. Eighty pedicle screws were placed using O-ARM and C-ARM each. Instrumentation was placed bilaterally in the thoracic (T1–T6) spine and lumbosacral junction (L5–S1) using a standard open technique, whereas minimally invasive surgery technique was used at the lumbar 3 to 4 (L3–L4) level. A “postoperative” computed tomography (CT) scan was performed on cadavers where instrumentation was done using the C-ARM. An independent musculoskeletal radiologist assessed final images for screw position. Time required to set up and instrumentation was recorded. Dosimeters were placed on multiple aspects of cadavers and surgeons to record radiation exposure. Results. There were no differences in breach rate between the O-ARM and C-ARM groups (5 vs. 7, &khgr;2= 0.63, P = 0.4). The setup time for the O-ARM group was longer than that for the C-ARM group (592 vs. 297 s, P < 0.05). However, the average total time was statistically the same (1629 vs. 1639 s, P = 0.96). Radiation exposure was higher for surgeons in the C-ARM group and cadavers in the O-ARM group. When a “postoperative” CT scan was included in the estimation of the total radiation exposure, there was less of difference between the groups, but still more for the O-ARM group. Conclusion. In cadavers without deformity, O-ARM use results in similar breach rates as C-ARM for the placement of pedicle screws. Time for instrumentation is shorter with the O-ARM, but requires a longer setup time. The O-ARM exposes less radiation to the surgeon, but higher doses to the cadaver. Level of Evidence: N/A

Minimally Invasive Transforaminal Lumbar Interbody Fusion

Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) is performed via tubular dilators thereby preserving the integrity of the paraspinal musculature. The decreased soft tissue disruption in the MIS technique has been associated with significantly decreased blood loss, shorter length of hospitalization, and an expedited return to work while maintaining comparable arthrodesis rates when compared with the open technique particularly in the setting of spondylolisthesis (isthmic and degenerative), recurrent symptomatic disk herniation, spinal stenosis, pseudoarthrosis, iatrogenic instability, and spinal trauma. The purpose of this article and the accompanying video wass to demonstrate the techniques for a primary, single-level MIS TLIF.

Type of bone graft or substitute does not affect outcome of spine fusion with instrumentation for adolescent idiopathic scoliosis.

Study Design. Retrospective cohort analysis. Objective. To compare clinical outcomes after spine instrumentation and fusion using 3 different bone grafts in children with adolescent idiopathic scoliosis (AIS). Summary of Background Data. Autogenous iliac crest bone graft (AIC) is the “gold standard” to promote fusion in posterior AIS operations, although the morbidity of harvest is a concern. There is limited data comparing outcomes after AIS surgery based on types of bone grafts. Methods. Children (10–18 yr) with AIS who underwent deformity correction via a posterior approach were identified in the Spinal Deformity Study Group database. All had a minimum of 2-year follow-up. Patients were subdivided into 3 groups based on bone graft used: AIC, allograft, and bone substitute (BS). Clinical data included patient demographics, operative details, postoperative analgesic use, and perioperative complications. Lenke curve type and curve magnitude changes were radiographically analyzed. The Scoliosis Research Society-30 questionnaire was used to assess clinical outcomes. Results. 461 patients met inclusion criteria (girls: 381, boys: 80; average age 14.7 ± 1.7) and consisted of 152 AIC patients (124 girls, 28 boys), 199 allograft patients (167 girls, 32 boys), and 110 BS patients (90 girls, 20 boys). There was no difference in age (P = 0.41) or gender (P = 0.82). The BS group had significantly smaller preoperative curves and shorter operative times. Postoperatively, patients who received BS had significantly longer hospital stays, used higher quantities of patient-controlled intravenous analgesia and used epidurals longer. The AIC group used patient-controlled intravenous analgesia significantly longer. There were no differences between the groups in regards to curve type, number of levels fused, postoperative infections, pseudarthrosis, reoperations for any indication, and Scoliosis Research Society-30 scores at the latest follow-up. Conclusion. Outcomes after primary posterior spinal fusion with instrumentation are not influenced by type of bone graft or substitute. Level of Evidence: 3

Urinary Tract Infection Following Posterior Lumbar Fusion Procedures: An American College of Surgeons National Surgical Quality Improvement Program Study.

Study Design. Retrospective review of prospectively collected data. Objective. To determine the incidence and risk factors for the development of a urinary tract infection (UTI) after a posterior lumbar fusion procedure. Summary of Background Data. UTI after surgery is common and has important clinical consequences for both patients and the health care system. Few studies have examined UTI after spinal fusion procedures. Methods. Patients undergoing posterior lumbar fusion procedures during 2011 to 2013 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Statistical comparisons were made using multivariate regression with adjustment for demographic, comorbidity, and operative characteristics. Results. A total of 10,825 patients met inclusion criteria. The incidence of a UTI was 1.77% (95% confidence interval = 1.52%–2.02%). Independent risk factors for a UTI were greater age (for 50–59 yr, relative risk [RR] = 1.0; 60–69 yr, RR = 2.1; ≥70 yr, RR = 3.5; P < 0.001), female sex (RR = 2.2, P < 0.001), dependent functional status (RR = 2.1, P = 0.010), malnutrition (RR = 2.3, P = 0.004), diabetic status (for non–insulin‐dependent diabetes, RR = 1.5; for insulin‐dependent diabetes, RR = 1.9; P = 0.011), and increased operative duration (for 120–179 min, RR = 1.4; 180–239 min, RR = 2.3; and for ≥240 min, RR = 2.7; P < 0.001). Patients who developed a UTI had a greater risk for systemic sepsis than other patients (11.5% vs. 0.63%; adjusted RR = 14.4, P < 0.001). Patients who developed a UTI had a greater risk for readmission than other patients (36.7% vs. 5.0%; adjusted RR = 6.1, P < 0.001). Conclusion. UTIs occur in nearly 1 in 50 patients undergoing posterior lumbar fusion procedures. Patients who are older, female, dependent, malnourished, or diabetic are at greater risk and should be counseled and monitored accordingly. In addition, morbidity associated with a UTI in this population is substantial, as demonstrated by a 14‐fold increase in the risk for systemic sepsis and a 6‐fold increase in the risk for readmission. As such, increased preventative measures should be targeted to the patients identified here to be at greatest risk. Level of Evidence: 3

Incidence and risk factors for pneumonia following anterior cervical decompression and fusion procedures: an ACS-NSQIP study

BACKGROUND CONTEXT Postoperative pneumonia has important clinical consequences for both patients and the health-care system. Few studies have examined pneumonia following anterior cervical decompression and fusion (ACDF) procedures. PURPOSE This study aimed to determine the incidence and risk factors for development of pneumonia following ACDF procedures. STUDY DESIGN/SETTING A retrospective cohort study of data collected prospectively by the American College of Surgeons National Surgical Quality Improvement Program was carried out. PATIENT SAMPLE This study comprised 11,353 patients undergoing ACDF procedures during 2011-2013. OUTCOME MEASURES The primary outcome was diagnosis of pneumonia in the first 30 postoperative days. METHODS Independent risk factors for the development of pneumonia were identified using multivariate regression. Readmission rates were compared between patients who did and did not develop pneumonia using multivariate regression that adjusted for all demographic, comorbidity, and procedural characteristics. RESULTS The incidence of pneumonia was 0.45% (95% confidence interval=0.33%-0.57%). In the multivariate analysis, independent risk factors for the development of pneumonia were greater age (p<.001), dependent functional status (relative risk [RR]=5.3, p<.001), chronic obstructive pulmonary disease (RR=4.4, p<.001), and greater operative duration (p=.020). Patients who developed pneumonia following discharge had a higher readmission rate than other patients (72.7% vs. 2.4%, adjusted RR=24.5, p<.001). In total, 10.2% of all readmissions were caused by pneumonia. CONCLUSIONS Pneumonia occurs in approximately 1 in 200 patients following ACDF procedures. Patients who are older, are functionally dependent, or have chronic obstructive pulmonary disease are at greater risk. These patients should be counseled, monitored, and targeted with preventative interventions accordingly. Greater operative duration is also an independent risk factor. Approximately three in four patients who develop pneumonia following hospitalization for ACDF procedures are readmitted. This elevated readmission rate has implications for bundled payments and hospital performance reports.

Quantification of Multifidus Atrophy and Fatty Infiltration Following a Minimally Invasive Microdiscectomy.

Background Multifidus muscle degeneration and atrophy have been demonstrated following traditional open spine surgery. The purpose of this study was to quantify multifidus muscle atrophy and fatty infiltration following a 1-level minimally invasive (MIS) lumbar discectomy. Methods Magnetic resonance imaging (MRI) of 24 patients who underwent a primary 1-level MIS microdiscectomy were reviewed. Demographics, operative levels, and time from surgery to imaging were assessed. Total and lean cross-sectional areas (CSA), T1-signal intensity ratio between the multifidus and psoas muscles, and lean-to-total CSA ratio were measured. Pre- and postoperative values were compared within each patient utilizing paired sample T-tests. Results The mean age was 47.8±14.2 years. MRI was obtained 182.5±194.4 days following index surgery. On the ipsilateral side, total CSA decreased at the index level (-4.9%) and the lean CSA decreased at the index (-6.2%), inferior pedicle (-13.0%), and inferior disc levels (-18.6%). On the contralateral side, no significant decreases in total or lean CSA were demonstrated. T1-signal intensity ratios increased at all levels, but the differences were not statistically significant. The lean-to-total CSA ratio was decreased at the superior disc (-5.2%), inferior pedicle (-8.4%), and inferior disc levels (-17.2%) on the ipsilateral side and at the contralateral inferior disc level (-5.3%). Conclusions Primary 1-level MIS discectomy results in minimal short-term atrophy and fatty infiltration of the multifidus at the index level. Total CSA atrophy was mainly confined to the ipsilateral side at the index level. Lean CSA atrophy was observed mainly at and below the index level on the ipsilateral side. Fatty infiltration, as measured by the lean-to-total CSA ratio, ranged 1.2-17.2% on the ipsilateral and 0-5.3% on the contralateral side with greater fat content demonstrated caudally to the surgical level. Clinical Relevance Overall, the majority of the multifidus muscle appears to be radiographically preserved following an MIS lumbar discectomy.

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

Decreased scapular notching with lateralization and inferior baseplate placement in reverse shoulder arthroplasty with high humeral inclination

Background: Scapular notching is a radiographic finding of unknown clinical significance following reverse total shoulder arthroplasty (RTSA). The purpose of this study was to determine how baseplate position affects the incidence of scapular notching and measure the clinical outcomes. Hypothesis: We hypothesized that low base plate position on the glenoid and new prosthesis design with a higher humeral inclination angle would decrease the incidence of notching at 2 years follow-up. Materials and methods: A total of 54 patients with an average follow-up of 30 months met inclusion criteria and underwent radiographic analysis of scapular notching and radiographic measures to determine glenoid component placement. Clinical measures including visual analog score, American Shoulder and Elbow Surgeons (ASES) scores, and range of motion (ROM) were prospectively collected. Results: Thirty-nine of the 54 patients had no notching. 7 had Grade 1 notching, 7 had Grade 2 notching, one had Grade 3, and one had Grade 4 notching. Notching was associated with higher placement of the glenoid component as measured by peg-glenoid rim distance and base plate distance. All patients with no evidence of notching at 1-year, continued to have no notching after multi-year follow-up. Clinical outcome measures including ASES scores, ROM, and visual analog pain scores were improved at follow-up. Conclusion: We concluded that lower neck-shaft angle and low baseplate positioning led to a low incidence of significant scapular notching as only 6 out of 57 (16%) patients had notching Grade 2 and above. At short-term follow-up, this RTSA results in excellent clinical outcomes and a significantly lower scapular notching rate than traditional techniques.

Current Trends in Outpatient Spine Surgery.

Because of the increasing pressure to contain health-care–related costs, the number of spinal surgeries performed in the outpatient setting has significantly increased. The higher perioperative efficiency and greater predictability of associated costs offer significant incentives for payers and providers to move surgical procedures into the outpatient setting. Nonetheless, judicious patient selection is advised to optimize outcomes.

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.