Introduction
Cervical spondylotic myelopathy (CSM) is a condition caused by spondylosis, ossification of the posterior longitudinal ligament, degenerative disc disease, and other pathologies that lead to progressive spinal cord dysfunction due to compression of the spinal cord [1,2]. CSM is a prevalent cause of spinal canal stenosis and leads to neck pain or stiffness, wide-based ataxic gait, paresthesias, deficient coordination, imbalance, and bladder problems among other neurological symptoms in adults [3,4]. As the sampleages and the incidence of CSM increase, the percentage of chronic disability has increased correspondingly contributing to the steady growth of years lost to handicap. Diverse prospective population studies have demonstrated positive clinical outcomes and halting of progression in patients who have experienced surgical treatment for CSM; therefore, surgery is the recommended treatment for patients with moderate to severe and progressive CSM [5–8].
The surgical technique must address both the static compression and dynamic tethering of the spinal cord characteristic of CSM and must be identified based on multiple considerations, including cervical sagittal alignment, etiology of compression, and patient characteristics [3,9–11]. The objective of surgical treatment is to prevent the progression of neurologic symptoms and further deterioration while addressing both the static and dynamic injury to the spinal cord [3]. However, there is a lack of rigorous evaluation comparing differences posterior laminectomy alone, (decompression alone), versus decompression and fusion surgery. Multilevel laminectomy may compromise the posterior tension band and potentially increase segmental mobility, which may lead to dynamic spinal cord injury, progressive kyphotic deformity, and instability ultimately causing deterioration [3,10]. the incidence of Post-laminectomy kyphosis in adultsranges from 6% to 47% and is a major concern [10,12–15]. Conversely, laminectomy with posterior instrumented fusion may lead to reduced motion and increased stiffness at the treated segments. Fusion surgery is more complex and carries additional risks compared to decompression alone, including implant-related complications [10,16]. Additionally, concerns exist regarding the cost-effectiveness of instrumentation [9,17,18].
According to the current literature and the lack of consensus on decompression-alone versus decompression with posterior instrumented fusion in patients with CSM, This research aimed to conduct a retrospective review of patients undergoing laminectomy without fusion and laminectomy with fusion from 2015 to 2020 National data from the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database was used to analyze differences in 30-day perioperative morbidity, mortality, and postoperative complications rates. We hypothesized that the cohort undergoing laminectomy with fusion would have an increased risk of perioperative complications compared to the decompression-alone groups.
Materials and Methods
Ethics statement
Informed approval was not required for this research as it utilizes anonymized retrospective data from the ACS-NSQIP national database. Institutional Review Board approval was not necessary for the completion of this research.
Study design
This is a retrospective population study using the ACS-NSQIP database, a medical chart-informed data registry that tracks surgical outcomes and complications to help surgeons and hospitals make data-driven decisions for patient care. NSQIP collects outcome (dependent) variables up to 30 days postoperatively.
Patient selection and data collection
Patient data were obtained from the ACS-NSQIP database from 2015 to 2020. Inclusion criteria included adults (≥18 years) diagnosed with cervical myelopathy (10th revision of the International Classification of Diseases [ICD-10]: M47.12) or spinal stenosis of the cervical region (ICD-10: M48.02) who underwent laminectomy (Current Procedural Terminology [CPT] 63001, 63015, 63045) with (CPT 22600) or without fusion as outlined in Table 1.
Patients were stratified into two cohortn
Laminectomy with fusion
The first cohort was laminectomy with fusion: CPT 63001+22600, laminectomy with exploration and/or decompression of the spinal cord and/or cauda equina, without facetectomy, foraminotomy or discectomy, involving one or two vertebral segments with single-level, posterior or posterolateral technique arthrodesis; CPT 63015+22600, laminectomy with exploration and/or decompression of spinal cord and/or cauda equina, without facetectomy, foraminotomy or discectomy, involving more than twovertebral segment with single-level, posterior or posterolateral technique arthrodesis; or CPT 63045+22600, laminectomy, facetectomy and foraminotomy, (unilateral or bilateral) with decompression of spinal cord, cauda equina and/or nerve root[s], at a single vertebral segment with single-level, posterior or posterolateral technique arthrodesis.
Laminectomy without fusion
The second cohort was laminectomy without fusion: CPT 63001, laminectomy with exploration and/or decompression of spinal cord and/or cauda equina, without facetectomy, foraminotomy or discectomy, involving one or two vertebral segments; CPT 63015, laminectomy with exploration and/or decompression of spinal cord and/or cauda equina, without facetectomy, foraminotomy or discectomy, involving more than twovertebral segment; or CPT 63045, laminectomy, facetectomy and foraminotomy (unilateral or bilateral) with patient cohort variables such as age and gender decompression of spinal cord, cauda equina and/or nerve root[s], at a single vertebral segment.
Independent variables
They were extracted directly from the NSQIP files. Comorbidity variables included diabetes (with and without insulin), hypertension (HTN), congestive heart failure, chronic obstructive pulmonary disease, smoking status, steroid use, American Society of Anesthesiologists (ASA) physical status classification, and functional status. The ASA status was extracted as a numerical variable without descriptors, and the functional status was categorized as “functional” or “non-functional.”
Postoperative outcome and complication variables
The outcome variables extracted for this research included mortality, morbidity, reintubation, unplanned reoperation (including the reason for reoperation, unplanned readmission (including the reason for readmission), operative times, and length of hospital stay (in days). Postoperative issues variables included superficial infection, deep wound infections, sepsis, bleeding requiring transfusions, deep vein thrombosis, pulmonary embolism, urinary tract infection, renal insufficiency, renal failure, myocardial infection, cardiac arrest, and stroke.
Statistical analysis
IBM SPSS Statistics for Windows ver. 28.0 (IBM Corp., Armonk, NY, USA) was used for all statistical analyses. Patient demographics, preoperative comorbidities, and perioperative characteristics were examined for their association with postoperative complications. A comparative analysis between the two cohorts was conducted using the chi-square test for categorical variables and analysis of variance (ANOVA). Additionally, the analysis of outcomes between the two groups was stratified by preoperative ASA score, ranging from 1 to 4. ASA I indicates a patient in good health, ASA II indicates a patient has a mild but well-managed condition, ASA III indicates a patient with a serious condition that affects overall health, and ASA IV indicates the presence of a severe life-threatening condition [19]. By organizing the statistical output by ASA groups, ANOVA with Tukey’s post hoc test and chi-square analyses were conducted with significance established at p<0.05. Patients with incomplete data for any variable were excluded from the analysis.
Results
Patient demographics
A total of 6,412 patients met the inclusion criteria. Of these, 3,355 (52%) underwent a laminectomy without fusion, and 3,057 (48%) experienced laminectomy with fusion. The mean age of the patients in the non-fusion cohort was 64±11.7 years while the mean age in the fusion cohort was 64±10.6 years. The percentage of males in the non-fusion cohort was 64.9% compared to 59.7% in the fusion cohort. There was no significant difference in the incidence of most medical comorbidities between the two groups, except for HTN and chronic obstructive pulmonary disease (COPD), which were statistically more prevalent in the fusion cohort (62.9% HTN, 7.4% COPD) compared to the non-fusion cohort (59.8% HTN, 6.2% COPD), with p=0.01 and p=0.046, respectively. The most prevalent comorbidity was HTN, present in 3,930 (61%) of the evaluated patients. Additionally, while preoperative functional status was not significantly different between the two groups, the mean ASA score was, with a mean of 2.7±0.6 in the non-fusion cohort and 2.8±0.6 in the fusion cohort (p<0.001). The characteristics of the two cohorts are presented in Table 2.
Multivariate analysis
A significant correlation was found between the treatment group and several postoperative complications (Table 3). Higher rates of mean morbidity, unplanned reoperation, unplanned readmission, mean length of stay, operative time, deep wound infection, bleeding risk necessitating transfusion, and pulmonary embolism were observed in patients undergoing laminectomy with fusion compared to those who did not receive a fusion. All variables for each complication subgroup are presented in Table 3.
Multivariate analysis of variance
An assessment of postoperative complications between the two treatment groups stratified by ASA score demonstrated a higher overall complication rate in patients with higher ASA scores. There was also an increased percentage of complications in the fusion cohort compared to the non-fusion cohort (Table 4). The distribution of patients across ASA categories was as follows: ASA I: 62 patients (0.97%), of whom 18 (29%) underwent a fusion procedure; ASA II: 1,892 patients (29.5%), with 770 (41%) undergoing fusion; ASA III: 4,022 patients (62.7%), with 2,040 (51%) undergoing fusion; and ASA IV: 433 patients (6.8%), with 229 (53%) undergoing fusion. In the ASA I category, a postoperative complication occurred in the non-fusion cohort (0.2%), identified as a deep wound infection. For ASA II patients, the overall complication rate was 5.0%, with 95 total complications. Among 1,122 patients in the non-fusion cohort, there were 49 complications (4.4%), while the fusion cohort had 46 complications (6.0%) among 770 patients. In the ASA III group, the overall complication rate was 10.9%, with 438 total complications. The non-fusion cohort experienced 182 complications (9.2%) among 1,982 patients, and the fusion cohort had 256 complications (12.5%) among 2,040 patients. Among ASA IV patients, the overall complication rate was 24%, with a total of 104 complications. There were 41 complications (20%) in the non-fusion cohort (204 patients), and 63 complications (27.5%) in the fusion cohort (229 patients). Additionally, in the ASA I, ASA II, and ASA III subgroups, there was a significant increase in mean morbidity for the fusion group compared to the non-fusion group (p=0.003 for ASA I; p<0.001 for ASA II and ASA III) (Table 4). However, within the ASA III subgroup, patients who underwent decompression without fusion had a higher risk of mortality (p=0.022). Furthermore, rates of reoperation and readmission were higher in ASA III patients who received a laminectomy with fusion (93 versus 58 requiring reoperation, p=0.006; 178 versus 145 requiring readmission, p=0.026). The average length of hospital stay for patients undergoing a fusion procedure was consistent across ASA I, II, and III patients (p<0.002 for ASA I; p<0.001 for ASA II and ASA III). When analyzing individual complications between the two cohorts stratified by ASA score, the following complications were significantly more frequent in the fusion group compared to the non-fusion group: ASA III: deep wound infection (p=0.005); ASA II and III: bleeding requiring transfusion (p<0.004 for ASA II, p<0.001 for ASA III); ASA II and III: pulmonary embolism (p=0.016 for ASA II, p=0.017 for ASA III); and ASA IV: myocardial infarction (p=0.029). However, in ASA III patients, the rates of renal insufficiency were higher in the non-fusion group compared to those who underwent fusion surgery (p=0.023).
Overall, the most common causes of unplanned reoperation were postoperative infection (ICD-10: T81.4) in the fusion group and postprocedural hematoma (ICD-10: G97.61) in the non-fusion group. The most common reoperation procedures were incision and drainage of deep abscesses (CPT 22010) in the fusion group, and incision and drainage of superficial abscesses (CPT 10140) in the non-fusion group.
Discussion
Both cervical laminectomy alone and laminectomy with instrumented fusion are accepted surgical treatments for patients with progressive CSM. However, there remains no consensus on which technique is more effective in improving functional handicap, as both have correlated risks and benefits and multiple research has demonstrated similar early postoperative outcomes between these techniques [3,10,11,20]. This research aims to investigate the differences in 30-day perioperative morbidity and mortality as well as rates postoperative complication rates in patients undergoing cervical laminectomy with and without fusion for CSM.
The comparative rates of perioperative morbidity and mortality and postoperative complications between laminectomy with instrumented fusion and laminectomy alone for CSM were evaluated in this study. A total of 6,412 patients were retrospectively reviewed, and revealing significant differences in complication rates between the decompression-alone group and the fusion group, patients in the fusion group had a significantly higher complication risk profile. Including higher rates of mean morbidity, unplanned reoperation, unplanned readmission, mean length of stay, deep wound infection, bleeding risk requiring transfusion, and pulmonary embolism compared to the decompression-alone group. Additionally, when stratified by ASA score, there was a linear increase in postoperative complication rates with higher ASA scores in both the fusion and decompression-alone groups, the fusion cohort exhibited a consistently higher complication rate across all ASA categories. However, Some of these differences were marginal and unlikely to be clinically significant despite the statistical significance. Given these findings, minimizing surgical duration for patients with higher ASA scores should be considered to mitigate risk. Overall, the risk of perioperative complications after conducting decompression and fusion procedures for CSM should be carefully weighed when determining the optimal surgical treatment plan for patients indicated for surgery.
A potential concern regarding posterior decompression alone for CSM is iatrogenic instability of the cervical spine which may necessitate revision surgery. The instability arises due to the detachment of the midline ligamentous structures and resection of the lamina, hypertrophic ligamentum flavum, and facet joints all of which contribute to spinal cord compression in a standard laminectomy. However, detaching these structures, , may compromise the posterior tension band and increase neck mobility, potentially leading to postoperative instability and kyphosis [10,21,22]. The use of Fusion for CSM has steadily increased from 1993 to 2002. However, while fusion may help prevent postoperative kyphosis it is also associated with significant outpatient resource utilization and costs, moreover, unsatisfactory outcomes have been reported in up to 30% of cases with postoperative complications occurring in 17% of patients, a risk that increases in those over the age of 70 [9,17,18,23–26]. Additionally, little data support a correlation between loss of sagittal alignment following cervical laminectomy and neurologic deterioration, or overall outcomes [15,27–29].
Ultimately, the benefits of laminectomy with fusion, including avoiding complications associated with spinal instability and kyphosis the normal, must be carefully weighed against the known risks. The addition of fusion to decompressive surgery has been shown to increase operative time, blood loss, and overall complications, all of which contribute to higher healthcare costs. Currently, There remains no consensus on the optimal surgical technique and no high-level evidence supports the routine addition of fusion to cervical laminectomy alone, with multiple studies demonstrating nearly equivalent early clinical outcomes between laminectomy without fusion with the addition of fusion surgery for CSM [3,10,11,28,30].
These findings must be interpreted within the limitations of the study design. This study is a retrospective review of a national database which inherently carries a risk of selection bias. Importantly, in the context of revision surgery and postoperative complications, the evaluation period is limited to only 30 days postoperatively. As a result, long-term sequelae-such as the need for, revision surgery for iatrogenic instability in decompressions alone and pseudoarthrosis, or neurologic association between several postoperative complications and surgical technique in patients with CSM does not establish an absolute criterion determining which technique is better suited for individual patients, the choice of surgical deterioration due to loss of sagittal cervical alignment and postlaminectomy kyphosis could not be assessed. Second, while this study identifies an approach ultimately depends on clinical presentation and imaging findings. Based on these results, patient-specific factors, including ASA score, which reflects a patient’s medical comorbidities, should be considered in surgical decision-making, weighing the risk of early perioperative complications in laminectomy with fusions against the potential for future instability with decompression alone.
Conclusions
To our knowledge, this study represents one of the largest comparisons between decompression-alone and decompression with fusion procedures in CSM patients indicated for surgery. The results suggest that adding a fusion to a decompression may lead to worse short-term perioperative outcomes, including a higher rate of morbidity, unplanned reoperation, unplanned readmission, mean length of stay, deep wound infection, bleeding risk necessitating transfusion, and pulmonary embolism, all of which contribute to increased healthcare costs. However, surgeon discretion should guide the decision on a case-by-case basis, balancing the potential risk of early complication in fusion procedures against the possibility of long-term instability and postlaminectomy kyphosis in patients undergoing cervical laminectomy alone. Additionally, Our findings suggest that a higher ASA score is predictive of early postoperative complications. Indicating that ASA may serve as a prognostic tool to help mitigate short-term surgical risk for patients undergoing decompression and fusion in CSM.
Key Points
This retrospective cohort study analyzed 6,412 patients from the American College of Surgeons National Quality Improvement Program database to compare 30-day perioperative outcomes of cervical laminectomy with versus without instrumented fusion for cervical spondylotic myelopathy (CSM).
Laminectomy with fusion was associated with significantly higher rates of morbidity, reoperations, readmissions, length of stay, deep wound infections, and bleeding requiring transfusion.
Across all American Society of Anesthesiologists (ASA) physical status classes, patients undergoing fusion experienced more postoperative complications than those treated with decompression alone, with a particularly notable increase in ASA III and IV groups.
This study suggests that decompression alone is a safer alternative compared to decompression with fusion for surgical management of CSM—especially in patients with high ASA scores—while emphasizing the need for individualized surgical decision-making.
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