Microendoscopic decompression for cervical spondylotic myelopathy

A novel endoscope-port unit for lumbar microendoscopic surgery: a single-center case series review

Minimally invasive spinal surgery has shown benefits not only from a clinical standpoint but also in some cost-effectiveness metrics. Microendoscopic procedures combine optical advantages of endoscopy with the preservation of bimanual surgical maneuvers that are not feasible with full percutaneous endoscopic procedures. TELIGEN is a new endoscopic platform designed to optimize these operations. Our aim was to present a retrospective review of surgical data from the first consecutive cases applying this device in our institution and describe some of its technical details. 25 patients have underwent procedures using this device at our institution to the date, with a mean follow-up of 341.7 ± 45.1 days. 17 decompression-only procedures, including microendoscopic discectomies (MED) and decompression of stenosis (MEDS), with or without foraminotomies (± MEF) and 8 microendoscopic transforaminal lumbar interbody fusions (ME-TLIF) were performed. Mean age and body mass index (BMI) were respectively 58.8 ± 17.4 years and 27.6 ± 5.3 kg/m2. Estimated blood loss (13 ± 4.8, 12.8 ± 6.98 and 76.3 ± 35.02 mL), postoperative length of hospital stay (11.2 ± 21.74, 22.1 ± 26.85 and 80.7 ± 44.60 h), operative time (130.3 ± 58.53, 121 ± 33.90 and 241.5 ± 45.27 min) and cumulative intraprocedural radiation dose (14.2 ± 6.36, 15.4 ± 12.17 and 72.8 ± 12.26 mGy) are reported in this paper for MED ± MEF, MEDS ± MEF and ME-TLIF, respectively. TELIGEN affords an expanded surgical field of view with unique engineered benefits that provide a promissing platform to enhance minimally invasive spine surgery.

Clinical efficacy and safety of posterior minimally invasive surgery in cervical spondylosis: a systematic review

Background

Posterior minimally invasive surgery has been increasingly used in in recent years for the clinical treatment of cervical spondylosis. However, this treatment remains challenging and has not been comprehensively reported. The aim of this study was to provide a systematic review of posterior minimally invasive treatment for cervical spondylosis to demonstrate the clinical efficacy and safety of this procedure.

Method

We collected information from patients with myelopathy or radiculopathy cervical spondylosis who underwent posterior minimally invasive surgery and verified the clinical efficacy and safety of these surgeries with different measurement indicators from five electronic databases: the Nurick, visual analog scale score, Japanese Orthopaedic Association (JOA) score, Neck Disability Index (NDI), EuroQol Five Dimensions Questionnaire (EQ-5D) score, Short-Form Health Survey Physical Component Summary (SF12-PCS) questionnaire score, Short-Form Health Survey Mental Component Summary (SF12-MCS) questionnaire score, and the MOS item short form health survey (HF-36) score. The decompression effect, cervical spine stability, average surgery time, surgical blood loss volume, length of hospital stay, and related complications were included in the descriptive analysis. Reporting of this protocol followed the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines checklist.

Results

We identified 14 observational studies of cervical spondylosis with 479 patients, mainly including 197 cases of myelopathy and 207 cases of radiculopathy. Channel and endoscopic techniques were used. This study was certified by PROSPERO: CRD42021290074. Significant improvements in the quantitative indicators (Neck-VAS in 9 studies, JOA in 7 studies, NDIs in 5 studies, Nurick, ARM-VAS, and EQ-5D in 2 studies each, and the SF12-PCS, SF12-MCS, and HF-36 in 1 study each) were observed between pre- and postoperation (P < 0.05), and satisfactory clinical significance was acquired in the descriptive indicators [average surgery time (94.56 ± 37.26 min), blood loss volume (68.78 ± 103.31 ml), average length of stay (2.39 ± 1.20 d), and cervical spine stability after surgery]. Additionally, we showed that there was a 4.9% postoperative complication rate and the types of complications that may occur.

Conclusion

Posterior minimally invasive surgery is an effective and safe method for the treatment of cervical spondylosis and is a recommended optional surgical procedure for single-segment myelopathy and radiculopathy.

Clinical Efficacy of Posterior Percutaneous Endoscopic Unilateral Laminotomy with Bilateral Decompression for Symptomatic Cervical Spondylotic Myelopathy

Objective

To compare the clinical efficacy of posterior percutaneous endoscopic unilateral laminotomy (PPEUL) and anterior cervical decompression and fusion (ACDF) in the treatment of single‐segment spondylotic myelopathy (CSM).

Methods

This is a retrospective research, from January 2017 to December 2019, 30 cases were included in the PPEUL group and 32 cases were included in the ACDF group. The operative duration, blood loss, length of stay, complications, Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score, MacNab classification and imaging data were collected preoperatively, postoperative 1‐week, final follow‐up and statistically analyzed.

Results

The surgery was completed successfully on all patients, and there were no serious complications, such as nerve or spinal cord injury or infection. In the PPEUL and ACDF groups, the operative duration were 56.63 ± 1.40 and 65.21 ± 2.45 min, the intraoperative blood loss were 51.69 ± 3.23 and 50.51 ± 5.48 mL, and the hospitalization duration was 5.75 ± 1.43 and 6.38 ± 2.16 days. The follow‐up period in the PPEUL and ACDF groups was 24.96 ± 1.12 months and 25.65 ± 1.45 months, respectively. There was no significant difference in intraoperative blood loss between the two groups, but the hospitalization and operative durations in the PPEUL group were significantly shorter than those in the ACDF group (P < 0.05). The VAS scores at postoperative 1 week and final follow‐up were significantly improved compared with those before surgery. The JOA scores at postoperative 1 week and final follow‐up were significantly improved compared with those before surgery, but there was no significant difference between the two groups at the last follow‐up. The intervertebral disc height of the adjacent segment at the last follow‐up was significantly lower in the ACDF group than in the PPEUL group (P < 0.05), but there was no significant difference between the two groups in the intervertebral disc height of the surgical segment (P > 0.05). The rate of excellent and good results was 90.0% and 87.5%, respectively. Postoperative cervical CT and MRI showed that the spinal canal was fully decompressed and spinal cord compression was relieved.

Conclusion

PPEUL has the advantages of reduced trauma, rapid recovery and remarkable curative efficacy, so it is a new choice for the treatment of CSM.

Optimizing the Application of Surgery for Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 10]

STUDY DESIGN

Literature Review (Narrative).

OBJECTIVE

To introduce the number 10 research priority for Degenerative Cervical Myelopathy: Individualizing Surgery.

METHODS

This article summarizes the current recommendations and indications for surgery, including how known prognostic factors such as injury time, age, disease severity, and associated comorbidities impact surgical outcome. It also considers key areas of uncertainty that should be the focus of future research.

RESULTS

While a small proportion of conservatively managed patients may remain stable, the majority will deteriorate over time. To date, surgical decompression is the mainstay of treatment, able to halt disease progression and improve neurologic function and quality of life for most patients. Whilst this recognition has led to recommendations on when to offer surgery, there remain many uncertainties including the type of surgery, or timing in milder and/or asymptomatic cases. Their clarification has the potential to transform outcomes, by ensuring surgery offers each individual its maximum benefit.

CONCLUSION

Developing the evidence to better guide surgical decision-making at the individual patient level is a research priority for Degenerative Cervical Myelopathy.

Biomechanical Analysis of Posterior Ligaments of Cervical Spine and Laminoplasty

Cervical laminoplasty is a valuable procedure for myelopathy but it is associated with complications such as increased kyphosis. The effect of ligament damage during cervical laminoplasty on biomechanics is not well understood. We developed the C2–C7 cervical spine finite element model and simulated C3–C6 double-door laminoplasty. Three models were created (a) intact, (b) laminoplasty-pre (model assuming that the ligamentum flavum (LF) between C3–C6 was preserved during surgery), and (c) laminoplasty-res (model assuming that the LF between C3–C6 was resected during surgery). The models were subjected to physiological loading, and the range of motion (ROM), intervertebral nucleus stress, and facet contact forces were analyzed under flexion/extension, lateral bending, and axial rotation. The maximum change in ROM was observed under flexion motion. Under flexion, ROM in the laminoplasty-pre model increased by 100.2%, 111.8%, and 98.6% compared to the intact model at C3–C4, C4–C5, and C5–C6, respectively. The ROM in laminoplasty-res further increased by 105.2%, 116.8%, and 101.8% compared to the intact model at C3–C4, C4–C5, and C5–C6, respectively. The maximum stress in the annulus/nucleus was observed under left bending at the C4–C5 segment where an increase of 139.5% and 229.6% compared to the intact model was observed for laminoplasty-pre and laminoplasty-res model, respectively. The highest facet contact forces were observed at C4–C5 under axial rotation, where an increase of 500.7% and 500.7% was observed compared to the intact model for laminoplasty-pre and laminoplasty-res, respectively. The posterior ligaments of the cervical spine play a vital role in restoring/stabilizing the cervical spine. When laminoplasty is performed, the surgeon needs to be careful not to injure the posterior soft tissue, including ligaments such as LF.

Ten-Step Minimally Invasive Cervical Decompression via Unilateral Tubular Laminotomy: Technical Note and Early Clinical Experience

BACKGROUND

Minimally invasive techniques utilizing tubular retractors have become an increasingly popular approach to the spinal column. The concept of a unilateral laminotomy for bilateral decompression (ULBD), first applied in the lumbar spine, has recently been applied to the cervical spine for the treatment of cervical spondylotic myelopathy (CSM). A better understanding of the indications and surgical techniques is required to effectively educate surgeons on how to appropriately and safely perform tubular cervical laminotomy via ULBD.

OBJECTIVE

To describe a 10-step technique for minimally invasive cervical laminotomy and report our early clinical experience.

METHODS

A retrospective review identified 15 patients with CSM who were treated with this procedure. Visual analogue scale (VAS), neck disability index (NDI), and modified Japanese Orthopaedic Association (mJOA) scores were obtained pre- and postoperatively.

RESULTS

The mean age of the 15 patients was 73.1 ± 6.8 yr. The median number of levels treated was 1 (range 1-3). Mean operative time was 125.3 ± 30.8 or 81.7 ± 19.2 min per level. Mean estimated blood loss was 57.3 ± 24.6 cc. Median postoperative hospital length of stay was 36 h. No complications were encountered. Median follow-up was 18 mo. Mean pre- and postoperative VAS were 6.4 ± 2.4 and 1.0 ± 0.8, respectively (P < .001). Mean pre- and postoperative NDI were 46.4 ± 19.2 and 7.0 ± 6.9, respectively (P < .001). Mean pre- and postoperative Mjoa were 11.3 ± 2.5 and 14.5 ± 0.5, respectively (P < .001).

CONCLUSION

In our early clinical experience, minimally invasive cervical ULBD is safe and effective. Adherence to the presented 10-step technique will allow surgeons to safely address bilateral cervical pathology while avoiding complications.

A Multicenter Observational Study on the Postoperative Outcomes of C3 Laminectomy in Cervical Double-door Laminoplasty

STUDY DESIGN

Multicenter retrospective observational study.

OBJECTIVE

To determine the differences between C3 laminectomy (LN) and C3 laminoplasty (LP) in cervical LP.

SUMMARY OF BACKGROUND DATA

Interlaminar bony fusion after cervical LP is reported to be related to a decrease in postoperative range of motion (ROM) or neurological disorder. However, it remains uncertain whether C3 LN affects patient-reported outcomes, especially after double-door LPs. Therefore, this study aimed to investigate the effect of C3 LN compared with C3 LP in cervical double-door LP.

PATIENTS AND METHODS

Using our prospective database, consecutive patients with degenerative cervical myelopathy undergoing cervical double-door LP in 7 hospitals between April 2017 and May 2018 were enrolled. Before and 1 year after the surgeries, we collected the details of patient background data, operative factors, radiologic findings such as C2-C7 ROM angle and C2-C3 interlaminar bony fusion, the Japanese Orthopaedic Association (JOA) score, postoperative satisfaction, neck pain, and patient-reported outcomes such as Short Form-12 (SF-12), EuroQol 5 Dimension (EQ-5D), Neck Disability Index (NDI), and the Core Outcome Measures Index (COMI) for the neck.

RESULTS

In all, 152 patients were enrolled, including 97 undergoing C3 LP and 55 undergoing C3 LN. There were no significant differences in patient background data, complications, and operative factors. C2-C3 interlaminar bony fusion occurred more often in the C3 LP group (22.6% vs. 5.7%). There were also no differences in the C2-C7 angle, C2-C7 ROM angle, the JOA score, patient satisfaction, neck pain, SF-12, EQ-5D, NDI, and COMI between the groups.

CONCLUSIONS

C2-C3 bony fusion after cervical double-door LP occurred more often in the C3 LP group than in the C3 LN group. C3 LN resulted in similar outcomes in complication rate, radiographic outcomes, and clinical outcomes compared with those of C3 LP.

LEVEL OF EVIDENCE

Level III.

Vertebral Body Replacement With an Anchored Expandable Titanium Cage in the Cervical Spine: A Clinical and Radiological Evaluation

BACKGROUND

Expandable cervical cages have been used successfully to reconstruct the anterior spinal column.

OBJECTIVE

To perform clinical and radiological evaluation of vertebral body replacement with an anchored expandable titanium cage in the cervical spine after single-level and 2-level corpectomies.

METHODS

Between 2011 and 2017, 40 patients underwent a single-level (N = 32) or 2-level (N = 8) anterior corpectomy and fusion using an anchored expandable vertebral body replacement cage. Clinical and radiological data at admission, postoperatively, and at 3- and 12-mo follow-up were retrospectively analyzed. Clinical assessment was performed via standardized neurological evaluation, Odom score, and McCormick classification. Radiological assessment was performed via evaluation of sagittal profile, postoperative position, fusion, and subsidence rates.

RESULTS

Mean last follow-up was 14.8 ± 7 mo. Overall clinical and myelopathy-related improvements were shown directly after operation and at last follow-up. A stable centralized positioning of cages was achieved in 37 patients (93%). A mild ventral (>1.5 mm) malplacement was noted in 3 patients (7%) without clinical consequences. Sagittal alignment and preoperative cervical kyphosis improved significantly (7.8° gain of lordosis) and remained stable. Mean preoperative height of operated segments increased by 10 mm postoperatively and remained stable. Fusion rate in non-neoplastic patients and subsidence rate at last follow-up comprised 87.5% and 17.8%. With exception of 1 patient suffering from severe osteoporosis and cage subsidence, no patient needed additional secondary stabilization.

CONCLUSION

Anterior corpectomy and fusion by an expandable anchored titanium cage with anchor screws without additional instrumentation resulted in overall clinical improvement and radiological anterior column support, achieving significant and reliable restoration of the physiological sagittal cervical profile.

Is Microendoscopic Discectomy Effective for Patients With Concomitant Lumbar Disc Herniation and Spondylolysis?

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

Although it is controversial whether to choose only discectomy or fusion surgery in patients with disc herniation and spondylolysis, we expected that aggravation of the spondylolysis may be prevented if posterior supporting muscles can be well-preserved without extensive exploration. The purpose of this study was to investigate the influence of L5 spondylolysis on surgical outcomes following microendoscopic discectomy (MED) in patients with concomitant lumbar disc herniation and spondylolysis.

METHODS

We reviewed 811 patients who underwent MED for L4/5 or L5/S1 disc herniation. Patients with spondylolisthesis were excluded. We compared surgical outcomes of patients with and without L5 spondylolysis, whose age, sex, and surgical level were matched.

RESULTS

A total of 655 patients (80.7%) with complete data were considered eligible for the study. MED was performed at L4/5 and L5/S1 in 338 and 317 patients, respectively. A total of 20 patients (3.1%) had concomitant L5 spondylolysis and disc herniation at L4/5 (9 patients) or L5S1 (11 patients). As we compared each outcome of the 20 patients having L5 spondylolysis with 40 matched patients without L5 spondylosis, there were no significant differences in preoperative or postoperative outcomes between the 2 groups, and no patient with spondylolysis had undergone additional surgery during the mean follow-up period of 24 months.

CONCLUSIONS

MED demonstrated good surgical results regardless of the presence or absence of spondylolysis. In patients with sciatica with concomitant disc herniation and spondylolysis, but without spondylolisthesis, fusion surgery may not be always necessary.

Microendoscopic anterior cervical foraminotomy: a preliminary series of 76 cases

Background

Anterior cervical foraminotomy represents a relatively recent minimally invasive approach that can potentially preserve the intervertebral disc and thus the functional motion segment.

Objective

This study aims to evaluate the clinical outcome of microendoscopic anterior cervical foraminotomy (MACF) for patients with cervical unilateral radiculopathy due to single level soft disc herniation or hard disc-osteophyte complex (DOC).

Methods

In the period between August 2009 and March 2015, 76 consecutive patients with symptomatic unilateral cervical radiculopathy were included in this study. There were 40 left-sided cervical radiculopathy cases and 36 right-sided; of those, 42 had soft disc fragment herniation, 18 had DOC, 12 had a migrated disc fragment whether cranial or caudal, and four had far lateral (foraminal) disc herniation. In all cases, MACF with root decompression was performed. Cervical magnetic resonance imaging (MRI), computed tomography (CT) scan, and plain X-rays were performed for all patients and then repeated postoperatively. All patients were followed-up for at least a year. Clinical and functional outcomes were assessed using visual analogue scale (VAS) and Odom’s criteria.

Results

According to VAS score, there was an improvement in neck pain from 6.4 (range 5–10) to 1.5 (1–5) and in arm pain from 7.2 (range 6–10) to 1.2 (0–4) at final follow-up (P < 0.05). Functional outcomes according to Odom’s criteria were excellent in 59 (78%) cases, good in ten (13%), fair in six (8%), and poor in one (1%) case. Success of surgery was considered to be achieved in 91% (excellent + good) of cases. Mean operating time was 81 min, and mean intraoperative blood loss was 21 ml. Most significant complications included a dural tear in one case, transient postoperative dysesthesia in six cases, excess bony work resulting in unintended uncinectomy in three cases, fracture of transverse process in one case, unintended near total discectomy in two cases, infective discitis in one case, and persistent radicular pain due to incomplete osteophyte removal in one case.

Conclusions

This preliminary report suggests that MACF yields overall excellent results in selected patients with unilateral cervical radiculopathy. The technique potentially can preserve the functional motion segment, thus patients typically experience immediate postoperative neck mobility and do not need to wear a cervical collar.

AOSpine Consensus Paper on Nomenclature for Working-Channel Endoscopic Spinal Procedures

STUDY DESIGN

International consensus paper on a unified nomenclature for full-endoscopic spine surgery.

OBJECTIVES

Minimally invasive endoscopic spinal procedures have undergone rapid development during the past decade. Evolution of working-channel endoscopes and surgical instruments as well as innovation in surgical techniques have expanded the types of spinal pathology that can be addressed. However, there is in the literature a heterogeneous nomenclature defining approach corridors and procedures, and this lack of common language has hampered communication between endoscopic spine surgeons, patients, hospitals, and insurance providers.

METHODS

The current report summarizes the nomenclature reported for working-channel endoscopic procedures that address cervical, thoracic, and lumbar spinal pathology.

RESULTS

We propose a uniform system that defines the working-channel endoscope (full-endoscopic), approach corridor (anterior, posterior, interlaminar, transforaminal), spinal segment (cervical, thoracic, lumbar), and procedure performed (eg, discectomy, foraminotomy). We suggest the following nomenclature for the most common full-endoscopic procedures: posterior endoscopic cervical foraminotomy (PECF), transforaminal endoscopic thoracic discectomy (TETD), transforaminal endoscopic lumbar discectomy (TELD), transforaminal lumbar foraminotomy (TELF), interlaminar endoscopic lumbar discectomy (IELD), interlaminar endoscopic lateral recess decompression (IE-LRD), and lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD).

CONCLUSIONS

We believe that it is critical to delineate a consensus nomenclature to facilitate uniformity of working-channel endoscopic procedures within academic scholarship. This will hopefully facilitate development, standardization of procedures, teaching, and widespread acceptance of full-endoscopic spinal procedures.

Selective nerve root block combined with posterior percutaneous cervical endoscopic discectomy for cervical spondylotic radiculopathy with double nerve root variation: A case report

RATIONALE

The aim of this report is to present the technique of selective nerve root blockage combined with posterior percutaneous cervical endoscopic discectomy (PPECD) for cervical spondylotic radiculopathy (CSR).

PATIENT CONCERNS

A 49-year-old female has pain in the skin area of the left scapular, pain in left elbow and limitation of left upper limb movement for 1.5 years.

DIAGNOSIS

She was diagnosed with CSR and C6-7 double nerve root variation.

INTERVENTIONS

We used selective nerve root block to determine the lesion segment and applied PPECD to relieve pressure on the patient's nerve roots.

OUTCOMES

The pain symptoms disappeared after the patient was treated with C6-7 nerve root block. Endoscopic displayed C6-7 double nerve root variation on the left side of the spinal cord intraoperative. The neurological function was intact postoperatively and no recurrence of cervical disc herniation during the 5 months' follow-up period. The hospitalization time was 5 days, the operation time was 68.2 minutes and the bleeding volume was 52.6 ml. There was no change in cervical curvature and cervical disc height postoperatively. Japanese Orthopaedic Association score, SF-36 score and Visual Analogue Scale score improved significantly postoperatively.

LESSONS

The application of selective nerve root blockage combined with PPECD for CSR could achieve satisfactory effect of position and decompression of the injured nerve root. Besides, we recommend that surgery be performed under general anesthesia to minimize patients' emotional stress and discomfort.

Comparison of outcomes following minimally invasive and open posterior cervical foraminotomy: description of minimally invasive technique and review of literature

Although minimally invasive posterior cervical foraminotomy (MIS-PCF) is frequently employed in the treatment of cervical radiculopathy, there are very few studies directly comparing outcomes between MIS-PCF and open posterior cervical foraminotomy and between MIS-PCF and percutaneous endoscopic (full-endoscopic) posterior cervical foraminotomy (FE-PCF). This study includes a description of technique and systematic review of literature and analysis of clinical studies comparing outcomes between MIS-PCF and open posterior cervical foraminotomy and between MIS-PCF and FE-PCF. Six comparative studies, including one randomized controlled trial were included in analysis. Average operative time ranged from 60.5 to 171 minutes in the open group and 77.65 to 115 minutes in the MIS group. Mean intraoperative blood loss ranged from 43.5 to 246 cc in the open group and 42 to 138 cc in the MIS group. Average postoperative length of stay ranged from 58.6 to 304.8 hours in the open group and 20 to 273.6 hours in the MIS group. Two studies reported significantly increased VAS-N (Neck) scores postoperatively in patients undergoing open cervical foraminotomies, however both studies reported that the differences lost statistical significance with longer follow-up. There were no significant differences in complications or reoperations between open and MIS groups. One retrospective cohort study was included in analysis that compared MIS-PCF and FE-PCF. Postoperatively at 24 months, mean NDI and VAS-N were significantly lower after FE-PCF than MIS-PCF. There was no significant change in VAS-A (Arm) between the two groups. Direct comparative studies between MIS-PCF and open cervical foraminotomy are limited in number. Although, there is a significant heterogeneity in studies comparing open and MIS-PCF there appears to be a trend of decreased hospital length of stay and postoperative analgesic usage in the minimally invasive cohort.

Comparison of microendoscopic selective laminectomy versus conventional laminoplasty in patients with degenerative cervcical myelopathy: a minimum 2-year follow-up study

Background

Although microendoscopic partial laminectomy for patients with degenerative cervical myelopathy (DCM) has been reported and demonstrated good results, a detailed comparison of its mid-term surgical results with those of laminoplasty (LP) has not been reported. The aim of this study was to compare the surgical outcomes, complications, and imaging parameters of cervical microendoscopic interlaminar decompression (CMID) via a midline approach versus conventional laminoplasty, with a minimum follow-up period of 2 years.

Methods

Two hundred and fifty-four patients who underwent either LP or CMID for DCM between May 2008 and April 2015 were enrolled. All patients routinely underwent LP (C3–6 or C3–7) before December 2011, whereas CMID was performed at the one or two affected level(s) only in patients with single- or two-level spinal cord compression after 2012.

Surgical procedure (CMID): For single-level patients (e.g., C5–6), partial laminectomy of C5 and C6 was performed under a microendoscope. For two-level patients (e.g., C5–6-7), decompression was completed by performing a C6 laminectomy.

We compared surgical outcomes and radiographic parameters between the CMID and LP groups.

Results

Of the 232 patients followed up for > 2 years, 87 patients with single- or two-level spinal cord compression, 46 that underwent CMID, and 41 that underwent LP were identified. There were no differences in the baseline demographic data of the patients between the groups. CMID showed better outcomes in terms of postoperative axial pain and quality of life, although both procedures showed good neurological improvement. Two and one patient complained of C5 palsy and hematoma, respectively, only in the LP group. The postoperative range of motion was worse and the degree of postoperative posterior spinal cord shift was larger in the LP group.

Conclusion

Selective decompression by CMID demonstrated surgical outcomes equivalent to those of conventional LP, which raises a question regarding the requirement of extensive posterior spinal cord shift in such patients. Although the indications of CMID are limited and comparison with anterior surgery is mandatory, it can be a minimally invasive procedure for DCM. 

Comparison of Health-related Quality of Life Between Double-door Laminoplasty and Selective Laminoplasty for Degenerative Cervical Myelopathy, With a Minimum Follow-up of 5 Years

STUDY DESIGN

A retrospective analysis of prospectively collected multicenter observational data.

OBJECTIVE

The aim of this study was to compare the health-related quality of life (HR-QOL) of double-door laminoplasty (DDL) and selective laminoplasty (SL) in patients with degenerative cervical myelopathy (DCM) in two institutions, with a minimum follow-up of 5 years.

SUMMARY OF BACKGROUND DATA

No study has compared DDL and SL regarding postoperative HR-QOL with a follow-up of more than 5 years.

METHODS

One-hundred ninety patients who underwent DDL (n = 77) or SL (n = 113) participated in this study. Short-form 36 (SF-36), Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), Neck Disability Index (NDI), and visual analog scale (VAS) values were compared between the groups.

RESULTS

Thirty-seven DDL and 52 SL patients were evaluated. The mean follow-up period was 8 years and the follow-up rate was 46.8%. No significant differences were found regarding age and JOA score at baseline. At the follow-up, there were no significant differences in SF-36, JOACMEQ, and VAS score, while the NDI score for headache and sleeping were higher in the SL group. After dividing the SL group into short and long SL subgroups, the long SL subgroup showed a significantly lower score in bodily pain in SF-36, lower and bladder function in JOACMEQ, and pain intensity, personal care, headaches, and sleeping in NDI compared with the other groups.

CONCLUSION

No significant differences were found in SF-36, JOA score, and NDI, except for the NDI subscale of headache and sleeping. The subgroup analysis showed that the long SL group showed a decreased QOL compared with the short SL and DDL groups.

LEVEL OF EVIDENCE

3.

Endoscopic Anterior Approach for Cervical Disc Disease (Disc Preserving Surgery)

OBJECTIVE

To report our experience of endoscopic disc removal by anterior approach for management of cervical myelopathy in 210 patients.

METHODS

A retrospective study of 187 cases of single- and 23 cases of double-level disc disease was performed. Cases of myelopathy with or without unilateral or bilateral radiculopathy and unilateral radiculopathy with either soft or hard disc prolapse were included. Patients with ≥3 disc levels, unstable spine, infections, trauma, significant posterior compression, congenital canal stenosis, disc extending more than half the vertebral body height, and prior surgery at the same level were excluded.

RESULTS

C5-6 (n = 119 patients), C6-7 (n = 58 patients), C4-5 (n = 49 patients), C3-4 (n = 6 patients), and C2-3 (n = 1 patient) levels were represented. Visual analog scale and Nurick grading system were used to assess severity of neck and arm pain and functional outcomes, respectively. Preoperative mean visual analog scale scores for arm and neck pain were 6.7 and 3.2, respectively, which improved to 1.7 and 1.1 at 3 months after surgery. The average preoperative Nurick grade improved from 2.64 to 0.81 at 6 months postoperatively. Follow-up was 6-54 months.

CONCLUSIONS

Endoscopic anterior discectomy (disc preserving surgery) is an effective and safe alternative in cervical disc disease. Although there was reduction in disc height, clinical outcome was good at an average 29 months of follow-up. Long-term follow-up is required to assess any progressive disc degeneration and clinical results.

State of the Art in Degenerative Cervical Myelopathy: An Update on Current Clinical Evidence

Degenerative cervical myelopathy (DCM) is a common cause of spinal cord dysfunction that confronts clinicians on a daily basis. Research performed over the past few decades has provided improved insight into the diagnosis, evaluation, and treatment of this disorder. We aim to provide clinicians with an update regarding the state of the art in DCM, focusing on more recent research pertaining to pathophysiology, natural history, treatment, consideration of the minimally symptomatic patient, surgical outcome prediction, and outcome measurement. Current concepts of pathophysiology focus on the combination of static and dynamic elements leading to breakdown of the blood-spinal cord barrier at the site of compression resulting in local inflammation, cellular dysfunction, and apoptosis. With respect to treatment, although there is a dearth of high-quality studies comparing surgical to nonoperative treatment, several large prospective studies have recently associated surgical management with clinically and statistically significant improvement in functional, disability, and quality of life outcome at long-term follow-up. When selecting the specific surgical intervention for a patient with DCM, anterior (discectomy, corpectomy, hybrid discectomy/corpectomy), posterior (laminectomy and fusion, laminoplasty), and combined approaches may be considered as options depending on the specifics of the patient in question; evidence supporting each of these approaches is reviewed in detail. Recently developed clinical prediction models allow for accurate forecasting of postoperative outcomes, permitting enhanced communication and management of patient expectations in the preoperative setting. Finally, an overview of outcome measures recommended for use in the assessment of DCM patients is provided.

Current Diagnosis and Management of Cervical Spondylotic Myelopathy

STUDY DESIGN

Review.

OBJECTIVES

Cervical spondylotic myelopathy (CSM) is a major cause of disability, particular in elderly patients. Awareness and understanding of CSM is imperative to facilitate early diagnosis and management. This review article addresses CSM with regard to its epidemiology, anatomical considerations, pathophysiology, clinical manifestations, imaging characteristics, treatment approaches and outcomes, and the cost-effectiveness of surgical options.

METHODS

The authors performed an extensive review of the peer-reviewed literature addressing the aforementioned objectives.

RESULTS

The clinical presentation and natural history of CSM is variable, alternating between quiescent and insidious to stepwise decline or rapid neurological deterioration. For mild CSM, conservative options could be employed with careful observation. However, surgical intervention has shown to be superior for moderate to severe CSM. The success of operative or conservative management of CSM is multifactorial and high-quality studies are lacking. The optimal surgical approach is still under debate, and can vary depending on the number of levels involved, location of the pathology and baseline cervical sagittal alignment.

CONCLUSIONS

Early recognition and treatment of CSM, before the onset of spinal cord damage, is essential for optimal outcomes. The goal of surgery is to decompress the cord with expansion of the spinal canal, while restoring cervical lordosis, and stabilizing when the risk of cervical kyphosis is high. Further high-quality randomized clinical studies with long-term follow up are still needed to further define the natural history and help predict the ideal surgical strategy.

A comparison of minimally invasive posterior cervical decompression and open anterior cervical decompression and instrumented fusion in the surgical management of degenerative cervical myelopathy

OBJECTIVE Minimally invasive posterior cervical decompression (miPCD) has been described in several case series with promising preliminary results. The object of the current study was to compare the clinical outcomes between patients undergoing miPCD with anterior cervical discectomy and instrumented fusion (ACDFi). METHODS A retrospective study of 74 patients undergoing surgery (45 using miPCD and 29 using ACDFi) for myelopathy was performed. Outcomes were categorized into short-term, intermediate, and long-term follow-up, corresponding to averages of 1.7, 7.7, and 30.9 months, respectively. Mean scores for the Neck Disability Index (NDI), neck visual analog scale (VAS) score, SF-12 Physical Component Summary (PCS), and SF-12 Mental Component Summary (MCS) were compared for each follow-up period. The percentage of patients meeting substantial clinical benefit (SCB) was also compared for each outcome measure. RESULTS Baseline patient characteristics were well-matched, with the exception that patients undergoing miPCD were older (mean age 57.6 ± 10.0 years [miPCD] vs 51.1 ± 9.2 years [ACDFi]; p = 0.006) and underwent surgery at more levels (mean 2.8 ± 0.9 levels [miPCD] vs 1.5 ± 0.7 levels [ACDFi]; p < 0.0001) while the ACDFi patients reported higher preoperative neck VAS scores (mean 3.8 ± 3.0 [miPCD] vs 5.4 ± 2.6 [ACDFi]; p = 0.047). The mean PCS, NDI, neck VAS, and MCS scores were not significantly different with the exception of the MCS score at the short-term follow-up period (mean 46.8 ± 10.6 [miPCD] vs 41.3 ± 10.7 [ACDFi]; p = 0.033). The percentage of patients reporting SCB based on thresholds derived for PCS, NDI, neck VAS, and MCS scores were not significantly different, with the exception of the PCS score at the intermediate follow-up period (52% [miPCD] vs 80% [ACDFi]; p = 0.011). CONCLUSIONS The current report suggests that the optimal surgical strategy in patients requiring dorsal surgery may be enhanced by the adoption of a minimally invasive surgical approach that appears to result in similar clinical outcomes when compared with a well-accepted strategy of ventral decompression and instrumented fusion. The current results suggest that future comparative effectiveness studies are warranted as the miPCD technique avoids instrumented fusion.

Cervical Endoscopic Laminoplasty for Cervical Myelopathy

STUDY DESIGN

Prospective clinical series.

OBJECTIVE

The aim of this study was to evaluate the safety, feasibility, and efficacy of a new minimally invasive laminoplasty technique for patients with cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

Posterior decompression is one of the most common surgical interventions for CSM. Conservative posterior approaches require extensive release and extensive retraction of paraspinal muscles and/or treatment of bone (lamina), which leads to postoperative axial neck pain and a decrease in lordosis and range of motion (ROM).

METHODS

A total of 45 patients with CSM received cervical microendoscopic laminoplasty (CMEL). Surgery included endoscopy-assisted bilateral laminoplasty with spinous process-ligament complex and deep extensor muscle retroposition. Bilateral titanium mini-screws and plates were used for fixation. Effects and axial symptoms were evaluated according to the Japanese Orthopedic Association (JOA) scores for neurological condition and visual analog scales (VAS) for axial neck pain, respectively. Cervical curvature index (CCI) and ROM were evaluated by X-ray. Computerized tomography and magnetic resonance imaging scans evaluated laminar healing and spinal cord decompression.

RESULTS

Follow-up ranged from 18 to 48 months (average 28 months). The duration of surgery averaged 119 minutes (range 62-147 min). Average blood loss was 360 mL (range 250-700 mL). Mean JOA scores improved from 8.0 ± 1.72 preoperatively to 13.29 ± 1.85 postoperatively. The effects were excellent in 13 cases, good in 25 cases, and fair in 7 cases. Axial symptoms were excellent in 16 cases, good in 18 cases, and fair in 11 cases. The VAS scores of axial pain significantly improved to 2.3 ± 2.0 at the final follow-up compared with 4.3 ± 2.1 preoperatively (P < 0.05). The CMEL procedure provided stable reconstruction of expanded laminar arches with no postoperative collapse or door-close. Sagittal spinal canal diameter increased by 1 to 3 mm. There were no differences in the pre- and postoperative CCI and ROM.

CONCLUSION

The new CMEL provides stable reconstruction of an expanded laminar arch and causes less damage to the spinous process-ligament complex and the deep extensor muscles than conventional surgical approaches. The CMEL procedure can be used efficiently and safely to treat CSM.

LEVEL OF EVIDENCE

N/A.

Current techniques in the management of cervical myelopathy and radiculopathy

Posterior decompressive procedures are a fundamental component of the surgical treatment of symptomatic cervical degenerative disease. Posterior approaches have the appeal of avoiding complications associated with anterior approaches such as esophageal injury, recurrent laryngeal nerve paralysis, dysphagia, and adjacent-level disease after fusion. Although open procedures are effective, the extensive subperiosteal stripping of the paraspinal musculature leads to increased blood loss, longer hospital stays, and more postoperative pain, and potentially contributes to instability. Minimally invasive access has been developed to limit approach-related morbidity. This article reviews current techniques in minimally invasive surgical management of cervical myelopathy and radiculopathy.