Utility of Posterior Longitudinal Ligament Resection During Anterior Cervical Decompression for Radiculopathy.

BACKGROUND: Anterior cervical diskectomy and fusion (ACDF) is the main surgical treatment of cervical radiculopathy. Controversy exists about the need to resect the posterior longitudinal ligament (PLL) to directly decompress the nerve roots, or if it is sufficient to indirectly decompress with diskectomy and graft placement. The objective of this study was to determine the effect of PLL resection after ACDF. METHODS: A retrospective review was performed of all patients that underwent first-time ACDF for cervical radiculopathy at a single tertiary care institution between 1999 and 2013. Comparative analyses and multivariable logistic regression were performed. RESULTS: Two hundred patients were included with a mean follow-up of 39 months. Average age was 54 years, 62% were women, and diabetes and current smoking status were noted in 11% and 15%, respectively. PLL resection was performed in 127 patients (64%), and no significant differences in baseline characteristics were observed between the 2 cohorts. One durotomy occurred in the resected PLL cohort, and none were seen in the unresected PLL group. No differences were seen in perioperative complications. At the time of last follow-up, improvement in radiculopathy was observed in 94% of the resected PLL group compared with 81% of the unresected PLL group (P = 0.008). After controlling for confounders, PLL resection had 3.8 times greater odds of leading to postoperative improvement in radiculopathy. CONCLUSIONS: ACDF leads to a high rate of success in improvement of preoperative radiculopathy. Excision of PLL during surgery leads to 3.8 times greater odds of improvement in this symptom, with no significant difference in the complication rate.

A retrospective cohort analysis of the effects of renin-angiotensin system inhibitors on spinal fusion in ACDF patients.

BACKGROUND CONTEXT: Recently, preclinical and clinical studies suggest an association between renin-angiotensin system (RAS) blockers and bone healing, particularly in the context of osteoporotic bone fractures. PURPOSE: To determine the correlation between the use of RAS inhibitors and fusion outcomes and neurologic status in anterior cervical discectomy and fusion (ACDF) surgery. STUDY DESIGN: Retrospective observational study. PATIENT SAMPLE: Patients who underwent ACDF for degenerative disorders. OUTCOME MEASURES: Spinal fusion status and neurologic function (modified Japanese Orthopedic Association [mJOA] and Nurick grading scales). METHODS: A retrospective chart review was performed, including 200 patients who underwent ACDF for degenerative disorders with 1-year minimum follow-up. Demographic data, comorbidities, antihypertensive medication, neurologic examination, and fusion status were collected. Spinal fusion was assessed via plain cervical x-ray, resorting to dynamic radiographs and/or computer tomography (CT) in cases of uncertainty. Preoperative mJOA and Nurick scores and recovery rates were calculated to determine neurologic status. RESULTS: Of the 200 patients (42.5% females, 57.5% males, median age of 53.7 years), 82 hypertensive patients were identified. Seventy-seven (93.9%) were taking antihypertensive medication as follows: 36.4% angiotensin-II receptor blockers (ARBs), 35.1% angiotensin-converting enzyme inhibitors (ACEIs), and the remaining patients were taking other medication. In the analysis of fusion rates, patients treated with ARBs exhibited a higher fusion rate, while those treated with ACEIs displayed a lower fusion rate compared to untreated nonhypertensive patients (p = .04 and .02, respectively). The difference in fusion rates between ARBs and ACEIs was also significant, with the former displaying higher rates (p < .001). Smoking exhibited a negative correlation with spinal fusion (p < .001). In the multivariate analysis, ARBs remained an independent factor for successful fusion (p = .02), while smoking remained a risk factor for failed fusion (p = .002). In the neurologic examination, ACEIs, hypertension status, and older age correlated with lower modified Japanese Orthopedic Association (mJOA) recovery rates (p = .001, <.001, and <.001, respectively) in the univariate analysis. CONCLUSIONS: In ACDF patients, we observed that ARBs were associated with higher fusion rates. Conversely, ACEIs and smoking were related to failed fusion. Prospective case-control studies are needed to confirm these RAS inhibitors effects on spinal fusion.

Diagnostic and therapeutic values of intraoperative electrophysiological neuromonitoring during resection of intradural extramedullary spinal tumors: a single-center retrospective cohort and meta-analysis.

OBJECTIVEWith the advent of intraoperative electrophysiological neuromonitoring (IONM), surgical outcomes of various neurosurgical pathologies, such as brain tumors and spinal deformities, have improved. However, its diagnostic and therapeutic value in resecting intradural extramedullary (ID-EM) spinal tumors has not been well documented in the literature. The objective of this study was to summarize the clinical results of IONM in patients with ID-EM spinal tumors.METHODSA retrospective patient database review identified 103 patients with ID-EM spinal tumors who underwent tumor resection with IONM (motor evoked potentials, somatosensory evoked potentials, and free-running electromyography) from January 2010 to December 2015. Patients were classified as those without any new neurological deficits at the 6-month follow-up (group A; n = 86) and those with new deficits (group B; n = 17). Baseline characteristics, clinical outcomes, and IONM findings were collected and statistically analyzed. In addition, a meta-analysis in compliance with the PRISMA guidelines was performed to estimate the overall pooled diagnostic accuracy of IONM in ID-EM spinal tumor resection.RESULTSNo intergroup differences were discovered between the groups regarding baseline characteristics and operative data. In multivariate analysis, significant IONM changes (p < 0.001) and tumor location (thoracic vs others, p = 0.018) were associated with new neurological deficits at the 6-month follow-up. In predicting these changes, IONM yielded a sensitivity of 82.4% (14/17), specificity of 90.7% (78/86), positive predictive value (PPV) of 63.6% (14/22), negative predictive value (NPV) of 96.3% (78/81), and area under the curve (AUC) of 0.893. The diagnostic value slightly decreased in patients with schwannomas (AUC = 0.875) and thoracic tumors (AUC = 0.842). Among 81 patients who did not demonstrate significant IONM changes at the end of surgery, 19 patients (23.5%) exhibited temporary intraoperative exacerbation of IONM signals, which were recovered by interruption of surgical maneuvers; none of these patients developed new neurological deficits postoperatively. Including the present study, 5 articles encompassing 323 patients were eligible for this meta-analysis, and the overall pooled diagnostic value of IONM was a sensitivity of 77.9%, a specificity of 91.1%, PPV of 56.7%, and NPV of 95.7%.CONCLUSIONSIONM for the resection of ID-EM spinal tumors is a reasonable modality to predict new postoperative neurological deficits at the 6-month follow-up. Future prospective studies are warranted to further elucidate its diagnostic and therapeutic utility.

Reoperation for Proximal Adjacent Segment Pathology in Posterior Cervical Fusion Constructs that Fuse to C2 vs C3.

BACKGROUND: Few studies have described rates of proximal clinical adjacent segment pathology (CASP) after posterior cervical decompression and fusion (PCDF). OBJECTIVE: To investigate rates of proximal CASP at C2 vs C3 in PCDFs for degenerative spine disease. METHODS: A retrospective review of 380 cases of PCDF for degenerative disease with proximal constructs ending at C2 vs C3 was performed. Minimum follow-up was 12 mo. The primary outcome was proximal CASP requiring reoperation. Variable analysis included demographic, operative, and complication data. RESULTS: There were 119 patients in the C2 group and 261 in the C3 group with no significant differences in age, gender, comorbidities, presenting symptoms, or complications. Vertebral artery injury rates were 0.8% in the C2 group and 0.0% in the C3 group (P = .12). No patients in the C2 group had reoperation for proximal CASP, while 5.0% of patients in the C3 group did (P = .01). Patients with arthrodesis up to C3 had an increased risk of proximal failure when the fusion construct crossed the cervicothoracic junction (P = .03). Multivariate logistic regression analysis showed no factors that were independently associated with re-instrumentation for proximal CASP. CONCLUSION: Instrumenting to the C2 level reduces the risk for proximal CASP compared to fusion only up to C3. The type of instrumentation used at these 2 levels, form of ASP disease at C1-C2, and natural motion of the relevant proximal adjacent joint may contribute to this difference. Furthermore, within the C3 cohort, fusion across the cervicothoracic junction increased the risk for proximal CASP.

Safety Profile of Lumbosacropelvic Fixation in Patients Aged 60 Years or Older: Comparison Between S2-Alar-Iliac Screws and Conventional Iliac Screws.

STUDY DESIGN: This is a retrospective study. OBJECTIVE: To report the safety profile of S2-alar-iliac (S2AI) in patients over 60, comparing S2AI screws with iliac screws (ISs). SUMMARY OF BACKGROUND DATA: The surgical management involving the lumbosacropelvic spine remains a challenge due to high mechanical demand and risk of pseudarthrosis. Previous articles showed lower rates of complications in patients receiving S2AI screws than ISs; however, none of them have focused on patients aged over 60 who may harbor significant comorbidities and thus require more meticulous perioperative management, given these invasive and lengthy procedures. MATERIALS AND METHODS: Retrospective review of clinical records from 2010 to 2015 identified 60 patients undergoing lumbosacropelvic fixation (17 patients with ISs and 43 patients with S2AI screws) who satisfied the following criteria: (1) patients aged over 60 years old and (2) patients with >1-year follow-up periods. Rates of complications such as unplanned reoperation and cardiorespiratory complications were collected and statistically analyzed. RESULTS: Baseline characteristics such as age, sex, and comorbidities were similar in both groups. The S2AI group had lower rates of reoperation (18.6% vs. 47.4%; P=0.02), surgical site infection (2.3% vs. 29.4%; P=0.006), wound dehiscence (2.3% vs. 29.4%; P=0.006), and postoperative anemia (7.0% vs. 29.4%; P=0.03) and had lower total volume of estimated blood loss (EBL) (mL) (1846.4 vs. 2721.2; P=0.02) and transfused red blood cell units (7.2 vs. 4.7; P=0.04) than the IS group, while rates of L5-S1 pseudarthrosis and other cardiorespiratory complications were similar in both groups. In multivariate analysis, operative time, body mass index, and use of S2AI screws over ISs were independent predictors of EBL. CONCLUSIONS: Use of S2AI screws over ISs in patients aged over 60 was associated with lower rates of reoperation, surgical site infection, wound dehiscence, and lower volume of EBL and red blood cell transfusion and is a viable surgical option.

Use of Recombinant Human Bone Morphogenetic Protein-2 at the C1-C2 Lateral Articulation without Posterior Structural Bone Graft in Posterior Atlantoaxial Fusion in Adult Patients.

BACKGROUND: Posterior atlantoaxial fusion is an important armamentarium for neurosurgeons to treat several pathologies involving the craniovertebral junction. Although the potential advantages of recombinant human bone morphogenetic protein-2 (rhBMP-2) are well documented in the lumbar spine, its indication for C1-C2 fusion has not been well characterized. In our institution, we apply rhBMP-2 to the C1-C2 joint either alone or with hydroxyapatite, locally harvested autograft chips, and/or morselized allogenic bone graft for selected cases-without conventional posterior structural bone graft. We report the clinical outcomes of the surgical technique to elucidate its feasibility. METHODS: We performed a single-center, retrospective review of data from 2008 to 2016 and identified 69 patients who had undergone posterior atlantoaxial fusion with rhBMP-2. The clinical records of these patients were reviewed, and the baseline characteristics, operative data, and postoperative complications were collected and statistically analyzed. RESULTS: The average age of the 69 patients was 60.8 ± 4.5 years, and 55.1% were women. With an average follow-up period of 21.1 ± 4.2 months, the C1-C2 fusion rate was 94.3% (65 of 69), and the average time to fusion was 11.4 ± 2.6 months (range, 5-23). The overall reoperation rate was 10.1% (7 of 69), with instrumentation failure in 7 patients (10.1%), adjacent segment disease in 2 (2.9%), and postoperative dysphagia and dyspnea in 2 patients (2.9%). No ectopic bone formation or soft tissue edema developed. CONCLUSIONS: Although retrospective and from a single center, our study has shown that rhBMP-2 usage at the C1-C2 joint without posterior structural bone grafting is a safe and reasonable surgical option.

Synovial Cyst as a Marker for Lumbar Instability: A Systematic Review and Meta-Analysis.

BACKGROUND: The pathogenesis of synovial cysts is largely unknown; however, they have been increasingly thought of as markers of spinal facet instability and typically associated with degenerative spondylosis. We specifically investigated the incidence of concomitant synovial cysts with underlying degenerative spondylolisthesis. METHODS: A literature search was performed using 4 online databases to assess the association between lumbar synovial cysts and degenerative spinal pathological features. Meta-analyses were performed on the prevalence rates of coexisting degenerative spinal pathological entities and treatment modalities. A random effects model was used to calculate the mean and 95% confidence intervals. RESULTS: A total of 17 studies encompassing 824 cases met the inclusion criteria. The pooled prevalence rates of concurrent spondylolisthesis, facet arthropathy, and degenerative disc disease at the same level of the synovial cysts were 42.5% (range, 39.0%-46.1%), 89.3% (range, 79.0%-94.8%), and 48.8% (range, 43.8%-53.9%), respectively. Among these, patients with coexisting spondylolisthesis were more likely to undergo spinal fusion surgery (vs. laminectomy alone) and reoperation than were patients without spondylolisthesis with a pooled odds ratio of 11.5 (95% confidence interval, 4.5-29.1; P < 0.0001) and 2.0 (95% confidence interval, 0.9-4.2; P = 0.088), respectively. CONCLUSIONS: Patients with a combination of synovial cysts and degenerative spondylolisthesis are more likely to undergo spinal fusion surgery than laminectomy alone compared with patients with synovial cysts and no preoperative spondylolisthesis. Furthermore, patients with synovial cysts and spondylolisthesis are more likely to require additional fusion surgery. The results from the present review lend credence to the argument that synovial cyst herniation might be a manifestation of an unstable spinal level.

Hippocampal Transection Plus Tumor Resection as a Novel Surgical Treatment for Temporal Lobe Epilepsy Associated with Cerebral Cavernous Malformations.

OBJECTIVE: The optimal surgical treatment for cavernous malformation-related temporal lobe epilepsy (CRTLE) is still controversial because it frequently involves the hippocampus as an epileptogenic zone. Here we describe our unique surgical strategy of performing hippocampal transection (HT) plus tumor resection for CRTLE to solve the question of how to balance postoperative seizure outcomes and neuropsychologic outcomes. METHODS: From 2005 to 2016, 7 cases of HT (3 on dominant side) plus tumor resection were performed for patients with CRTLE. We routinely perform intraoperative electrocorticography just before and after the resection of the tumor with hemosiderin rim. In cases with residual spikes from the hippocampus after the resection, we add HT, considering laterality of the lesion, preoperative memory functions, and magnetic resonance imaging abnormalities in hippocampi. Patient information, including seizure outcomes and preoperative and postoperative (24 months) Wechsler Memory Scale-Revised (WMS-R), were collected. RESULTS: In the mean follow-up of 62.7 months (range 20-119), the postoperative seizure outcome was as follows: Engel class I in 6 cases (85.7%) and II in 1 case (14.3%). Perioperative changes in WMS-R score were as follows: 93.5 preoperatively versus 99.5 postoperatively (P = 0.408) in verbal memory and 90.7 versus 98.0 (P = 0.351) in delayed recall. Overall, no patient presented with more than 25% decline in any of the WMS-R indices postoperatively. CONCLUSIONS: Despite the small sample size and noncontrolled study design, postoperative seizure outcomes were deemed acceptable with favorable memory outcomes, which rather improved postoperatively with marginal statistical significance. In patients with CRTLE, additional HT is a reasonable treatment option.

Coflex interspinous implant placement leading to synovial cyst development: case report.

Interspinous process devices (IPDs) have been developed as less-invasive alternatives to spinal fusion with the goal of decompressing the spinal canal and preserving segmental motion. IPD implantation is proposed to treat symptoms of lumbar spinal stenosis that improve during flexion. Recent indications of IPD include lumbar facet joint syndrome, which is seen in patients with mainly low-back pain. Long-term outcomes in this subset of patients are largely unknown. The authors present a previously unreported complication of coflex (IPD) placement: the development of a large compressive lumbar synovial cyst. A 64-year-old woman underwent IPD implantation (coflex) at L4-5 at an outside hospital for low-back pain that occasionally radiates to the right leg. Postoperatively, her back and right leg pain persisted and worsened. MRI was repeated and showed a new, large synovial cyst at the previously treated level, severely compressing the patient's cauda equina. Four months later, she underwent removal of the interspinous process implant, bilateral laminectomy, facetectomy, synovial cyst resection, interbody fusion, and stabilization. At the 3-month follow-up, she reported significant back pain improvement with some residual leg pain. This case suggests that facet arthrosis may not be an appropriate indication for placement of coflex.

Iatrogenic Spondylolisthesis Following Open Lumbar Laminectomy: Case Series and Review of the Literature.

OBJECTIVE: To present diagnosis and surgical management of postlaminectomy spondylolisthesis in patients without preoperative instability and a review of relevant literature. METHODS: Medical records and radiographic studies of 105 patients who underwent first-time bilateral 1- to 4-level open laminectomies for degenerative lumbar disease at a single academic institution were reviewed. Patients who initially presented with listhesis and had additional discectomy or fusion procedures were excluded. RESULTS: Of 105 patients with laminectomies across 1-4 levels, 10 patients (9.5%; 5 men and 5 women with average age of 63.0 ± 11.2 years) developed subsequent iatrogenic spondylolisthesis at the same operative levels that required reoperation. New or worsening low back pain and lower extremity pain were reported over an average period of 19.0 ± 17.5 months postoperatively. Imaging studies showed new spondylolisthesis that was not present before the index surgery, most commonly at L4-L5 level. All patients were treated surgically with posterior instrumented fusion. The average period between the first and second surgery was 32.6 ± 19.9 months. Surgical reduction of spondylolisthesis resulted in significant clinical improvement of patients' symptoms. CONCLUSIONS: In patients without overt pre-existing instability, laminectomy for lumbar stenosis can disrupt spinal stability and result in iatrogenic spondylolisthesis. The extent of decompression of the facet joints, number of levels decompressed, and preoperative disc space height can help assess the risk of postoperative spondylolisthesis. Patients who develop recurrent radiculopathy after decompressive lumbar laminectomy should be evaluated for potential iatrogenic spondylolisthesis.

Relationship between depression and clinical outcome following anterior cervical discectomy and fusion.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure for patients with symptomatic degenerative conditions of the cervical spine. The objective is to assess the impact of preoperative depression and other baseline characteristics on patient reported clinical outcomes following ACDF surgery based on the experience at our institution. METHODS: This was a retrospective cohort study of some patients undergoing ACDF at a single institution from 2012 to 2014. Ninety-three patients that underwent an ACDF procedure were included. The primary outcome measure was post-operative Nurick score. RESULTS: Sixteen (17.2%) patients had a formal diagnosis of depression compared to 77 (82.8%) patients without depression. On univariate analysis, patients with depression had statistically significantly higher Nurick scores compared to patients without depression after surgery (coefficient =0.55, 95% CI: 0.21-0.90, P=0.002). On multivariate analysis, there was a trend toward higher postoperative Nurick scores in patients that had depression (coefficient =0.31, 95% CI: -0.01-0.63, P=0.057). CONCLUSIONS: This small retrospective study reveals an inverse relationship between preoperative depression and functional outcome. Further research should be performed to investigate this relationship and to investigate if treating depression can improve postoperative outcomes.

Streptococcus intermedius: an unusual cause of spinal epidural abscess.

Spinal epidural abscess (SEA) following dental procedures is a rarely reported entity. Here, we present a unique case of a 74-year-old immunocompetent man who developed severe lower back pain and bilateral lower extremity weakness 4 days following two root canal procedures. Lumbar spine magnetic resonance imaging (MRI) showed several pockets of epidural abscesses extending from L1 through L5. Blood cultures grew Streptococcus intermedius, an anaerobic commensal bacterium of the normal flora of the mouth and upper airways. The patient was treated with IV penicillin for 7 days but his symptoms continued to deteriorate. A repeat MRI showed extension of the epidural abscess to T10-T11 level. The patient was emergently transferred to our hospital where he underwent bilateral decompressive laminectomy of T10 through S1 and abscess evacuation. Pus culture was positive for Streptococcus intermedius, which confirmed the diagnosis and the treatment plan. He was discharged on intravenous (IV) penicillin for 6 weeks. His symptoms improved significantly postoperatively as he retained his baseline strength in his lower extremity.

Prognostic Value of Preoperative Nurick Grade and Time with Symptoms in Patients with Cervical Myelopathy and Gait Impairment.

OBJECTIVE: To investigate the prognostic value of preoperative Nurick grade and time with symptoms for gait improvement and recovery in patients with ataxia secondary to cervical myelopathy. METHODS: A retrospective chart review of all adult patients who underwent surgical decompression for cervical myelopathy between 1996 and 2013 was performed. Only adults with a Nurick grade of at least 2 or worse were included. Outcome measures included gait improvement and recovery. RESULTS: A total of 170 patients were identified. Gait improvement and gait recovery occurred in 57.7% and 45.9% of patients, respectively. Time to improvement occurred as early as 1 month up to 24 months postoperatively. A greater preoperative Nurick grade was associated with lower odds of gait improvement (odds ratio 0.74; 95% confidence interval 0.53-0.99, P = 0.048) and gait recovery (odds ratio 0.27; 95% confidence interval 0.17-0.43, P < 0.001). The proportion of patients with symptoms for 12 months or less that experienced gait improvement was 71.2%, compared with 36.4% for patients with symptoms for over 12 months (P < 0.001). Patients with symptoms for 12 months or less had a 59.6% gait recovery rate, compared to 24.2% in patients with symptoms for over 12 months (P < 0.001). Having symptoms for over 12 months was independently associated with lower odds of improvement and recovery. CONCLUSIONS: Patients with a greater preoperative Nurick grade and symptoms for more than 12 months may have significantly lower odds of experiencing gait improvement or gait recovery after surgery for cervical myelopathy. This study's conclusion favors early intervention in patients with cervical myelopathy.

Role of glycemic control on hospital-related outcomes in patients with diabetes mellitus undergoing renal transplantation.

OBJECTIVE: To compare length of stay (LOS) and incidence of hypoglycemic events and infections in hospitalized patients with diabetes mellitus (DM) undergoing renal transplantation, among groups of patients defined by admission glucose and mean inpatient daily glucose. METHODS: A retrospective analysis of 190 charts of patients with DM who underwent renal transplantation over a 2-year period was conducted. Patients were grouped according to admission glucose and mean inpatient daily glucose (≤140 mg/dL, 141-180 mg/dL, and >180 mg/dL). RESULTS: Admission glucose was not associated with LOS. A mean inpatient daily glucose of ≤140 mg/dL was associated with a longer LOS compared to a mean inpatient daily glucose of >180 mg/dL (p=0.03). Patients with an admission glucose of ≤140 mg/dL had approximately half the rate of hypoglycemic events compared to those with admission glucose of 141-180 mg/dL (odds ratio [OR]=2.1; p=0.02) or >180 mg/dL (OR=1.9; p=0.04). However, patients whose mean daily glucose was ≤140 mg/dL had approximately twice the rate of hypoglycemic events than those whose mean daily glucose was 141-180 mg/dL (OR=0.4; p=0.01) or >180 mg/dL (OR=0.4; p=0.004). The incidence of infections was low and was not associated with admission or mean daily glucose levels. CONCLUSION: Lower mean daily inpatient glucose levels (≤140 mg/dL) are associated with longer LOS and greater incidence of hypoglycemic episodes in diabetes patients undergoing renal transplantation. Our findings suggest that target blood glucose levels of 140-180 mg/dL may be appropriate in this specific population. Additional prospective research is needed to confirm these findings.

The "patient experience": a quality metric to be aware of.

COMMENTARY ON: Etier BE Jr, Orr SP, Antonetti J, Thomas SB, Theiss SM. Factors impacting Press Ganey patient satisfaction scores in orthopedic surgery spine clinic. Spine J 2016:16:1285-9. (in this issue).

Long-term clinical outcomes following 3- and 4-level anterior cervical discectomy and fusion.

OBJECTIVE The purpose of this study was to report the long-term clinical outcomes following 3- and 4-level anterior cervical discectomy and fusion (ACDF). METHODS A retrospective review of all adult neurosurgical patients undergoing elective ACDF for degenerative disease at a single institution between 1996 and 2013 was performed. Patients who underwent first-time 3- or 4-level ACDF were included; patients with previous cervical spine surgery, those undergoing anterior/posterior approaches, and those with corpectomy were excluded. Outcome measures included perioperative complication rates, fusion rates, need for revision surgery, Nurick Scores, Odom's criteria, symptom resolution, neck visual analog scale (VAS) pain score, and persistent narcotics usage. RESULTS Seventy-one patients who underwent 3-level ACDF and 26 patients who underwent 4-level ACDF were identified and followed for an average of 7.6 ± 4.2 years. There was 1 case (3.9%) of deep wound infection in the 4-level group and 1 case in the 3-level group (1.4%; p = 0.454). Postoperatively, 31% of patients in the 4-level group complained of dysphagia, compared with 12.7% in the 3-level group (p = 0.038). The fusion rate was 84.6% after 4-level ACDF and 94.4% after 3-level ACDF (p = 0.122). At last follow-up, a significantly higher proportion of patients in the 4-level group continued to have axial neck pain (53.8%) than in the 3-level group (31%; p = 0.039); the daily oral morphine equivalent dose was significantly higher in the 4-level group (143 ± 97 mg/day) than in the 3-level group (25 ± 10 mg/day; p = 0.030). Outcomes based on Odom's criteria were also different between cohorts (p = 0.044), with a significantly lower proportion of patients in the 4-level ACDF group experiencing an excellent/good outcome. CONCLUSIONS In this study, patients who underwent 4-level ACDF had significantly higher rates of dysphagia, postoperative neck pain, and postoperative narcotic usage when compared with patients who underwent 3-level ACDF. Pseudarthrosis and deep wound infection rates were also higher in the 4-level group, although this did not reach statistical significance. Additionally, a smaller proportion of patients achieved a good/excellent outcome in the 4-level group than in the 3-level group. These findings suggest a significant increase of perioperative morbidity and worsened outcomes for patients who undergo 4- versus 3-level ACDF.