Laminectomy alone versus laminectomy with fusion for degenerative cervical myelopathy: a long-term study of a national cohort

The effect of high-normal preoperative international normalized ratios on postoperative outcomes and complications following posterior cervical spine surgery

INTRODUCTION

Current guidelines recommend that the International Normalized Ratio (INR) be less than 1.5 prior to spine intervention. Recent studies have shown that an INR > 1.25 is associated worse outcomes following anterior cervical surgery. We sought to determine the risk of complications associated with an INR > 1.25 following elective posterior cervical surgery.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was queried. Patients undergoing elective posterior cervical surgery from 2012 to 2016 with an INR level within 24 h of surgery were included. Primary outcomes were hematoma requiring surgery, 30-day mortality, and transfusions within 72-hours. There were 815 patients in the INR ≤ 1 cohort (Cohort A), 410 patients in the 1 < INR ≤ 1.25 cohort (Cohort B), and 33 patients in the 1.25 < INR ≤ 1.5 cohort (Cohort C).

RESULTS

Cohort C had a higher rate of transfusion (4% Cohort A; 6% Cohort B; 12% Cohort C; p = 0.028) and the rate of mortality within 30 days postoperatively trended toward significance (0.4% Cohort A; 0.5% Cohort B; 3% Cohort C; p = 0.094). There was no significant difference in the rate of postoperative hematoma formation requiring surgery (0.2% Cohort A; 0% Cohort B; 0% Cohort C; p = 0.58). On multivariate analysis, increasing INR was not associated with an increased risk of developing a major complication.

CONCLUSION

An INR > 1.25 but ≤ 1.5 may be safe for posterior cervical surgery. An INR > 1.25 but ≤ 1.5 was associated with a significantly higher rate of transfusions. However, increasing INR was not significantly associated with increased risk of any of the major complications.

Global Tendencies and Frontier Topics in Cervical Laminoplasty: A Bibliometric Analysis from 1982 to 2023

BACKGROUND

This bibliometric analysis aimed to map the knowledge network of laminoplasty research.

METHODS

Studies on laminoplasty published from 1982 to 2023 were retrieved from the Web of Science Core Collection (WoSCC). The contributions of countries, institutions, authors, and journals were identified using VOSviewer, Scimago Graphica, and Microsoft Excel. Tendencies, hotspots, and knowledge networks were analyzed and visualized using VOSviewer and CiteSpace.

RESULTS

We identified 2577 publications on laminoplasty. The annual number of publications exhibited an overall increasing trend since 2004. Among these, Japan, China, and the United States were the 3 major contributing countries. Keio University, Nagoya University, and Tokyo Medical & Dental University were the 3 most productive institutions. Shiro Imagama ranked first among authors regarding the number of articles, while K Hirabayashi was first among co-cited authors. Spine was the top journal in terms of the number of publications, citations, and co-citations. In addition, the research topics can be divided into 3 clusters: (1) Comparison between laminoplasty and other surgery in outcomes and complications; (2) Axial symptoms in laminoplasty; (3) Sagittal alignment and sagittal balance in laminoplasty. Emerging topics sagittal alignment and sagittal balance in degenerative cervical spondylosis are identified as current research frontiers.

CONCLUSIONS

This study drew a knowledge map of the top countries, institutions, authors, publications, and journals on laminoplasty over the past 4 decades. The current and future hotspots of laminoplasty focus on sagittal balance, comparison between other surgery in outcomes and complication, and axial symptoms in laminoplasty.

Cervical kyphosis after posterior cervical laminectomy with and without fusion

BACKGROUND

Cervical posterior instrumentation and fusion is often performed to avoid post-laminectomy kyphosis. However, larger comparative analyses of cervical laminectomy with or without fusion are sparse.

METHODS

A retrospective, two-center, comparative cohort study included patients after stand-alone dorsal laminectomy with (n = 91) or without (n = 46) additional fusion for degenerative cervical myelopathy with a median follow-up of 59 (interquartile range (IQR) 52) months. The primary outcome was the C2-7 Cobb angle and secondary outcomes were Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) scale, revision rates, T1 slope and C2-7 sagittal vertical axis (C2-7 SVA) at final follow-up. Logistic regression analysis adjusted for potential confounders (i.e. age, operated levels, and follow-up).

RESULTS

Preoperative C2-7 Cobb angle and T1 slope were higher in the laminectomy group, while the C2-7 SVA was similar. The decrease in C2-7 Cobb angle from pre- to postoperatively was more pronounced in the laminectomy group (- 6° (IQR 20) versus -1° (IQR 7), p = 0.002). When adjusting for confounders, the decrease in C2-7 Cobb angle remained higher in the laminectomy group (coefficient - 12 (95% confidence interval (CI) -18 to -5), p = 0.001). However, there were no adjusted differences for postoperative NDI (- 11 (- 23 to 2), p = 0.10), mJOA, revision rates, T1 slope and C2-7 SVA.

CONCLUSION

Posterior cervical laminectomy without fusion is associated with mild loss of cervical lordosis of around 6° in the mid-term after approximately five years, however without any clinical relevance regarding NDI or mJOA in well-selected patients (particularly in shorter segment laminectomies of < 3 levels).

Cost-effectiveness of surgery for degenerative cervical myelopathy in the United Kingdom

PURPOSE

Degenerative cervical myelopathy (DCM) is the commonest cause of adult spinal cord dysfunction worldwide, for which surgery is the mainstay of treatment. At present, there is limited literature on the costs associated with the surgical management of DCM, and none from the United Kingdom (UK). This study aimed to evaluate the cost-effectiveness of DCM surgery within the National Health Service, UK.

MATERIALS AND METHODS

Incidence of DCM was identified from the Hospital Episode Statistics (HES) database for a single year using five ICD-10 diagnostic codes to represent DCM. Health Resource Group (HRG) data was used to estimate the mean incremental surgery (treatment) costs compared to non-surgical care, and the incremental effect (quality adjusted life year (QALY) gain) was based on data from a previous study. A cost per QALY value of <£30,000/QALY (GBP) was considered acceptable and cost-effective, as per the National Institute for Health and Clinical Excellence (NICE) guidance. A sensitivity analysis was undertaken (±5%, ±10% and ±20%) to account for variance in both the cost of admission and QALY gain.

RESULTS

The total number of admissions for DCM in 2018 was 4,218. Mean age was 62 years, with 54% of admissions being of working age (18-65 years). The overall estimated cost of admissions for DCM was £38,871,534 for the year. The mean incremental (per patient) cost of surgical management of DCM was estimated to be £9,216 (ranged £2,358 to £9,304), with a QALY gain of 0.64, giving an estimated cost per QALY value of £14,399/QALY. Varying the QALY gain by ±20%, resulted in cost/QALY figures between £12,000 (+20%) and £17,999 (-20%).

CONCLUSIONS

Surgery is estimated to be a cost-effective treatment of DCM amongst the UK population.

Long-Term Results After Surgery for Degenerative Cervical Myelopathy

BACKGROUND AND OBJECTIVES

Degenerative cervical myelopathy (DCM) is a frequent cause of spinal cord dysfunction, and surgical treatment is considered safe and effective. Long-term results after surgery are limited. This study investigated long-term clinical outcomes through data from the Norwegian registry for spine surgery.

METHODS

Patients operated at the university hospitals serving Central and Northern Norway were approached for long-term follow-up after 3 to 8 years. The primary outcome was change in the Neck Disability Index, and the secondary outcomes were changes in the European Myelopathy Scale score, quality of life (EuroQoL EQ-5D); numeric rating scales (NRS) for headache, neck pain, and arm pain; and perceived benefit of surgery assessed by the Global Perceived Effect scale from 1 year to long-term follow-up.

RESULTS

We included 144 patients operated between January 2013 and June 2018. In total, 123 participants (85.4%) provided patient-reported outcome measures (PROMs) at long-term follow-up. There was no significant change in PROMs from 1 year to long-term follow-up, including Neck Disability Index (mean 1.0, 95% CI -2.1-4.1, P = .53), European Myelopathy Scale score (mean -0.3, 95% CI -0.7-0.1, P = .09), EQ-5D index score (mean -0.02, 95% CI -0.09-0.05, P = .51), NRS neck pain (mean 0.3 95% CI -0.2-0.9, P = .22), NRS arm pain (mean -0.1, 95% CI -0.8-0.5, P = .70), and NRS headache (mean 0.4, 95% CI -0.1-0.9, P = .11). According to Global Perceived Effect assessments, 106/121 patients (87.6%) reported to be stable or improved ("complete recovery," "much better," "slightly better," or "unchanged") at long-term follow-up compared with 88.1% at 1 year. Dichotomizing the outcome data based on severity of DCM did not demonstrate significant changes either.

CONCLUSION

Long-term follow-up of patients undergoing surgery for DCM demonstrates persistence of statistically significant and clinically meaningful improvement across a wide range of PROMs.

Comparison of the patient-derived modified Japanese Orthopaedic Association scale and the European myelopathy score

PURPOSE

To compare the patient-derived modified Japanese Orthopaedic Association (P-mJOA) scale with the European myelopathy score (EMS) for the assessment of patients with degenerative cervical myelopathy (DCM).

METHODS

In this register-based cohort study with prospectively collected data, included patients were surgically treated for DCM and had reported both P-mJOA and EMS scores at baseline, 1-year follow-up, and/or 2-year follow-up to the Swedish Spine Register. P-mJOA and EMS scores were defined as severe (P-mJOA 0-11 and EMS 5-8), moderate (P-mJOA 12-14 and EMS 9-12), or mild (P-mJOA 15-18 and EMS 13-18). P-mJOA and EMS mean scores were compared, and agreement was evaluated with Spearman's rank correlation coefficient (ρ), the intraclass correlation coefficient (ICC), and kappa (κ) statistics.

RESULTS

Included patients (n = 714, mean age 63.2 years, 42.2% female) completed 937 pairs of the P-mJOA and the EMS. The mean P-mJOA and EMS scores were 13.9 ± 3.0 and 14.5 ± 2.7, respectively (mean difference -0.61 [95% CI -0.72 to -0.51; p < 0.001]). Spearman's ρ was 0.84 (p < 0.001), and intra-rater agreement measured with ICC was 0.83 (p < 0.001). Agreement of severity level measured with unweighted and weighted κ was fair (κ = 0.22 [p < 0.001]; κ = 0.34 [p < 0.001], respectively). Severity levels were significantly higher using the P-mJOA (p < 0.001).

CONCLUSION

The P-mJOA and the EMS had similar mean scores, and intra-rater agreement was high, whereas severity levels only demonstrated fair agreement. The EMS has a lower sensitivity for detecting severe myelopathy but shows an increasing agreement with the P-mJOA for milder disease severity. A larger interval to define severe myelopathy with the EMS is recommended.

Anterior vs Posterior Surgery for Patients With Degenerative Cervical Myelopathy: An Observational Study From the Canadian Spine Outcomes and Research Network

BACKGROUND AND OBJECTIVES

The advantages and disadvantages of anterior vs posterior surgical approaches for patients with progressive degenerative cervical myelopathy (DCM) remain uncertain. Our primary objective was to evaluate patient-reported disability at 1 year after surgery. Our secondary objectives were to evaluate differences in patient profiles selected for each approach in routine clinical practice and to compare neurological function, neck and arm pain, health-related quality of life, adverse events, and rates of reoperations.

METHODS

We analyzed data from patients with DCM who were enrolled in an ongoing multicenter prospective observational cohort study. We controlled for differences in baseline characteristics and numbers of spinal levels treated using multivariable logistic regression. Adverse events were collected according to the Spinal Adverse Events Severity protocol.

RESULTS

Among 559 patients, 261 (47%) underwent anterior surgery while 298 (53%) underwent posterior surgery. Patients treated posteriorly had significantly worse DCM severity and a greater number of vertebral levels involved. After adjusting for confounders, there was no significant difference between approaches for odds of achieving the minimum clinically important difference for the Neck Disability Index (odds ratio 1.23, 95% CI 0.82 to 1.86, P = .31). There was also no significant difference for change in modified Japanese Orthopedic Association scores, and differences in neck and arm pain and health-related quality of life did not exceed minimum clinically important differences. Patients treated anteriorly experienced greater rates of dysphagia, whereas patients treated posteriorly experienced greater rates of wound complications, neurological complications, and reoperations.

CONCLUSION

Patients selected for posterior surgery had worse DCM and a greater number of vertebral levels involved. Despite this, anterior and posterior surgeries were associated with similar improvements in disability, neurological function, pain, and quality of life. Anterior surgery had a more favorable profile of adverse events, which suggests it might be a preferred option when feasible.

MRI-based measurements of spondylolisthesis and kyphosis in degenerative cervical myelopathy

BACKGROUND

To provide normative data and to determine accuracy and reliability of preoperative measurements of spondylolisthesis and kyphosis on supine static magnetic resonance imaging (MRI) of patients with degenerative cervical myelopathy.

METHODS

T2-weighted midsagittal images of the cervical spine were in 100 cases reviewed twice by one junior observer, with an interval of 3 months, and once by a senior observer. The spondylolisthesis slip (SSlip, mm) and the modified K-line interval (mK-line INT, mm) were assessed for accuracy with the standard error of measurement (SEm) and the minimum detectable change (MDC). Intraobserver and interobserver reliability levels were determined using the intraclass correlation coefficient (ICC).

RESULTS

The SEm was 0.5 mm (95% CI 0.4-0.6) for spondylolisthesis and 0.6 mm (95% CI 0.5-0.7) for kyphosis. The MDC, i.e., the smallest difference between two examinations that can be detected with statistical certainty, was 1.5 mm (95% CI 1.2-1.8) for spondylolisthesis and 1.6 mm (95% CI 1.3-1.8) for kyphosis. The highest reliability levels were seen between the second observation of the junior examiner and the senior observer (ICC = 0.80 [95% CI 0.70-0.87] and ICC = 0.96 [95% CI 0.94-0.98] for SSlip and mK-line INT, respectively).

CONCLUSIONS

This study provides normative values of alignment measurements of spondylolisthesis and kyphosis in DCM patients. It further shows the importance of taking measurement errors into account when defining cut-off values for cervical deformity parameters and their potential clinical application in surgical decision-making.

Methodology of economic evaluations in spine surgery: a systematic review and qualitative assessment

OBJECTIVES

The present study is a systematic review conducted as part of a methodological approach to develop evidence-based recommendations for economic evaluations in spine surgery. The aim of this systematic review is to evaluate the methodology and quality of currently available clinical cost-effectiveness studies in spine surgery.

STUDY DESIGN

Systematic literature review.

DATA SOURCES

PubMed, Web of Science, Embase, Cochrane, Cumulative Index to Nursing and Allied Health Literature, EconLit and The National Institute for Health Research Economic Evaluation Database were searched through 8 December 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were included if they met all of the following eligibility criteria: (1) spine surgery, (2) the study cost-effectiveness and (3) clinical study. Model-based studies were excluded.

DATA EXTRACTION AND SYNTHESIS

The following data items were extracted and evaluated: pathology, number of participants, intervention(s), year, country, study design, time horizon, comparator(s), utility measurement, effectivity measurement, costs measured, perspective, main result and study quality.

RESULTS

130 economic evaluations were included. Seventy-four of these studies were retrospective studies. The majority of the studies had a time horizon shorter than 2 years. Utility measures varied between the EuroQol 5 dimensions and variations of the Short-Form Health Survey. Effect measures varied widely between Visual Analogue Scale for pain, Neck Disability Index, Oswestry Disability Index, reoperation rates and adverse events. All studies included direct costs from a healthcare perspective. Indirect costs were included in 47 studies. Total Consensus Health Economic Criteria scores ranged from 2 to 18, with a mean score of 12.0 over all 130 studies.

CONCLUSIONS

The comparability of economic evaluations in spine surgery is extremely low due to different study designs, follow-up duration and outcome measurements such as utility, effectiveness and costs. This illustrates the need for uniformity in conducting and reporting economic evaluations in spine surgery.

Laminoplasty is relevant for degenerative cervical spondylolisthesis when there is little risk of postoperative excessive kyphosis during neck flexion

BACKGROUND

Elderly patients with degenerative cervical myelopathy frequently have severe symptoms due to spondylolisthesis. The effectiveness of laminoplasty for degenerative cervical spondylolisthesis (DCS) is an important question.

OBJECTIVE

The aim of this study is to elucidate factors associated with the outcome of laminoplasty for DCS.

METHOD

Eighty-nine patients with cervical spondylotic myelopathy (CSM) who underwent laminoplasty without instrumented posterior fusion were enrolled. Positive spondylolisthesis was defined as more than 2 mm during neck flexion or extension, from this, 46 DCS cases and 43 non-DCS cases were classified. Radiological parameters, including cervical alignment, balance, range of motion, and slippage along with the Japanese Orthopedic Association (JOA) score, were obtained before and 1 year after surgery. Factors associated with good surgical outcomes for DCS were analyzed using multivariate logistic analysis.

RESULTS

There were no significant differences in background and preoperative JOA score, but the DCS group recovery rate was significantly less (42% vs 53%). Multivariate logistic analysis revealed only the postoperative C2-7 angle during neck flexion was associated with a favorable outcome for DCS (P = 0.0039, Odds ratio: 1.49, 95% CI: 1.14-1.94). Multivariate regression analysis positively correlated the preoperative C2-7 angle in neutral and during flexion with the postoperative C2-7 angle during flexion.

CONCLUSION

The major factor related to poor outcome was the magnitude of postoperative kyphotic C2-7 angle during neck flexion. Slippage was not directly related to outcome and postoperative cervical alignment. Caution is recommended for surgeons performing laminoplasty on patients with risk factors for postoperative excessive kyphotic C2-7 angle during flexion.

Comparison of posterior muscle-preserving selective laminectomy and laminectomy with fusion for treating cervical spondylotic myelopathy: study protocol for a randomized controlled trial

BACKGROUND

Cervical spondylotic myelopathy (CSM) is the predominant cause of spinal cord dysfunction in the elderly. The patients are often frail and susceptible to complications. Posterior surgical techniques involving non-fusion are complicated by postlaminectomy kyphosis and instrumented fusion techniques by distal junction kyphosis, pseudarthrosis, or implant failure. The optimal surgical approach is still a matter of controversy. Since anterior and posterior fusion techniques have been compared without presenting any superiority, the objective of this study is to compare stand-alone laminectomy with laminectomy and fusion to determine which treatment has the lowest frequency of reoperations.

METHODS

This is a multicenter randomized, controlled, parallel-group non-inferiority trial. A total of 300 adult patients are allocated in a ratio of 1:1. The primary endpoint is reoperation for any reason at 5 years of follow-up. Sample size and power calculation were performed by estimating the reoperation rate after laminectomy to 3.5% and after laminectomy with fusion to 7.4% based on the data from the Swedish spine registry (Swespine) on patients with CSM. Secondary outcomes are the patient-derived Japanese Orthopaedic Association (P-mJOA) score, Neck Disability Index (NDI), European Quality of Life Five Dimensions (EQ-5D), Numeric Rating Scale (NRS) for neck and arm pain, Hospital Anxiety and Depression Scale (HADS), development of kyphosis measured as the cervical sagittal vertical axis (cSVA), and death. Clinical and radiological follow-up is performed at 3, 12, 24, and 60 months after surgery. The main inclusion criterium is 1-4 levels of CSM in the subaxial spine, C3-C7. The REDcap software will be used for safe data management. Data will be analyzed according to the modified intention to treat (mITT) population, defined as randomized patients who are still alive without having emigrated or left the study after 2 and 5 years.

DISCUSSION

This will be the first randomized controlled trial comparing two of the most common surgical treatments for CSM: the posterior muscle-preserving selective laminectomy and posterior laminectomy with instrumented fusion. The results of the myelopathy randomized controlled (MyRanC) study will provide surgical treatment recommendations for CSM. This may result in improvements in surgical treatment and clinical practice regarding CSM.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04936074 . Registered on 23 June 2021.

Unilateral Biportal Endoscopic Laminectomy for Treating Cervical Stenosis: A Technical Note and Preliminary Results

Objective: The objective of this study was to introduce a surgical technique for the percutaneous decompression of cervical stenosis (CS) using a unilateral biportal endoscopic approach and characterize its early clinical and radiographic results. Materials and Methods: Nineteen consecutive patients with CS who needed surgical intervention were recruited. All enrolled patients underwent unilateral biportal endoscopic laminectomy (UBEL). All patients were followed postoperatively for >1 year. The preoperative and final follow-up evaluations included the Japanese Orthopedic Association (JOA) score for neurological assessment, visual analogue scale (VAS) for axial pain and C2-C7 Cobb angle for cervical sagittal alignment. The postoperative complications were analyzed. Results: Thirteen males and six females were included in the analysis. The mean follow-up period was 16.3 ± 2.6 months. The mean operative time was 82.6 ± 18.4 min. Postoperative MRI and CT revealed ideal neural decompression of the treated segments in all patients. Preoperative VAS and JOA scores improved significantly after the surgery, and cervical lordosis was preserved on the postoperative images. Conclusions: UBEL was an effective surgical method for CS, which may also minimize iatrogenic damage to the posterior tension band (PTB) and help to maximize the preservation of the cervical lordosis.

Influence of preoperative depression on clinical outcomes after cervical laminoplasty: A retrospective study

Background

Depression is a highly prevalent mental disorder, and we found that patients with preoperative depression had worse postoperative improvement in lumbar fusion. Are mental factors related to the prognosis of laminoplasty?

Objective

To analyze the relationship between depression and clinical outcomes after laminoplasty for the treatment of multilevel CSM.

Methods

In this retrospective study, 115 patients with multilevel cervical spondylotic myelopathy (CSM), who underwent laminoplasty and were followed up for more than 1 year, were enrolled in this study from October 2018 to October 2021. Patients with the scores of 21-item Beck Depression Inventory (BDI) ≥ 15 or Hamilton Depression Scale-24 (HAMD-24) > 20 were included in the depression group. The clinical outcomes were evaluated by the changes and recovery rate (RR) of Japanese Orthopaedic Association Scores (JOA) and Neck Disability Index (NDI) respectively. Univariate and multiple linear regression analyses were performed to reveal the relationship between preoperative depressive states and clinical outcomes.

Results

Fourteen patients were diagnosed with depression by BDI and twenty-nine by HAMD-24. Between the depression group and the non-depression group, the age, gender, smoking history, and duration of symptoms were statistically significant (P < 0.05). Multiple linear regression showed that the BDI scores had a negative relationship with the changes and RR of JOA and NDI, and the HAMD-24 scores had a negative relationship with the changes and RR of JOA.

Conclusions

Preoperative depression in patients with multilevel CSM can lead to worse prognosis. In order to improve the curative effect of the operation, we should pay attention to the psychological state monitoring and intervention of patients before they receive laminoplasty.

Improvement rates, adverse events and predictors of clinical outcome following surgery for degenerative cervical myelopathy

PURPOSE

To investigate improvement rates, adverse events and predictors of clinical outcome after laminectomy alone (LAM) or laminectomy with instrumented fusion (LAM + F) for degenerative cervical myelopathy (DCM).

METHODS

This is a post hoc analysis of a previously published DCM cohort. Improvement rates for European myelopathy score (EMS) and Neck Disability Index (NDI) at 2- and 5-year follow-ups and adverse events are presented descriptively for available cases. Predictor endpoints were EMS and NDI scores at follow-ups, surgeon- and patient-reported complications, and reoperation-free interval. For predictors, univariate and multivariable models were fitted to imputed data.

RESULTS

Mean age of patients (LAM n = 412; LAM + F n = 305) was 68 years, and 37.4% were women. LAM + F patients had more severe spondylolisthesis and less severe kyphosis at baseline, more surgeon-reported complications, more patient-reported complications, and more reoperations (p ≤ 0.05). After imputation, the overall EMS improvement rate was 43.8% at 2 years and 36.3% at 5 years. At follow-ups, worse EMS scores were independent predictors of worse EMS outcomes and older age and worse NDI scores were independent predictors of worse NDI outcomes. LAM + F was associated with more surgeon-reported complications (ratio 1.81; 95% CI 1.17-2.80; p = 0.008). More operated levels were associated with more patient-reported complications (ratio 1.12; 95% CI 1.02-1.22; p = 0.012) and a shorter reoperation-free interval (hazard ratio 1.30; 95% CI 1.08-1.58; p = 0.046).

CONCLUSIONS

These findings suggest that surgical intervention at an earlier myelopathy stage might be beneficial and that less invasive procedures are preferable in this patient population.

Evaluating a paradigm shift from anterior decompression and fusion to muscle-preserving selective laminectomy: a single-center study of degenerative cervical myelopathy

OBJECTIVE

Muscle-preserving selective laminectomy (SL) is an alternative to conventional decompression surgery in patients with degenerative cervical myelopathy (DCM). It is less invasive, preserves the extensor musculature, and maintains the range of motion of the cervical spine. Therefore, the preferred treatment for DCM at the authors' institution has changed from anterior decompression and fusion (ADF), including anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF), toward SL. The aim of this study was to evaluate surgical outcomes before and after this paradigm shift with patient-reported outcome measures (PROMs), complications, reoperations, and cost-effectiveness.

METHODS

This study was a retrospective register-based cohort study. All patients with DCM who underwent ADF or SL at the authors' institution from 2008 to 2019 were reviewed. Using ANCOVA, changes in PROMs from baseline to the 2-year follow-up were compared between the two groups, adjusting for clinicodemographic parameters, baseline PROMs, number of decompressed levels, and MRI measurements (C2-7 Cobb angle, C2-7 sagittal vertical axis [SVA], and modified K-line interval [mK-line INT]). The PROMs, including the European Myelopathy Score (EMS), the Neck Disability Index (NDI), and the EQ-5D, were collected from the national Swedish Spine Register. Complications, reoperations, and in-hospital treatment costs were also compared between the two groups.

RESULTS

Ninety patients (mean age 60.7 years, 51 men [57%]) were included in the ADF group and 63 patients (mean age 68.8 years, 41 men [65%]) in the SL group. The ADF and SL groups had similar PROMs at baseline. The preoperative MR images showed similar C2-7 Cobb angles (10.7° [ADF] vs 14.1° [SL], p = 0.12) and mK-line INTs (4.08 vs 4.88 mm, p = 0.07), but different C2-7 SVA values (16.2 vs 19.3 mm, p = 0.04). The comparison of ANCOVA-adjusted mean changes in PROMs from baseline to the 2-year follow-up presented no significant differences between the groups (EMS, p = 0.901; NDI, p = 0.639; EQ-5D, p = 0.378; and EQ-5D health, p = 0.418). The overall complication rate was twice as high in the ADF group (22.2% vs 9.5%, p = 0.049), while the reoperation rate was comparable (16.7% vs 7.9%, p = 0.146). The average in-hospital treatment cost per patient was $6617 (USD) for SL, $7046 for ACDF, and $12,000 for ACCF.

CONCLUSIONS

SL provides similar PROMs after 2 years, a significantly lower complication rate, and better cost-effectiveness compared with ADF.