Surgical Management Of Cervical Myelopathy Research Articles

Are Functional Gains Durable After Decompressive Surgery for Cervical Myelopathy?: Commentary on an article by Victor Hin Ting Yick, MBBS, et al.: "Neurological Survivorship Following Surgery for Degenerative Cervical Myelopathy. A Longitudinal Study on 195 Patients".

Commentary In degenerative cervical myelopathy, spine surgeons generally accept the concept that patients will show clinically meaningful improvement after spinal cord decompression. At a minimum, the spine literature and common sense support the notion that cord decompression will at least halt ongoing neurological deterioration. Surgeons may debate the best method of decompression (anterior or posterior) and whether decompression with fusion is necessary, but there is little dissension with regard to the need for a surgical procedure in the setting of moderate to severe myelopathy1. The extent to which early neurological improvement after the surgical treatment of degenerative cervical myelopathy is sustained in the long term is unknown. Using the concept of neurological survivorship and Kaplan-Meier curves, Yick et al. demonstrate that, although most patients improve after decompressive surgery, not all of these good early results are durable. The authors found that as many as 17.9% of patients will see a recurrent decline in neurological function by 10 years, and most of these patients who underwent failed treatment (74.3%) underwent a revision surgical procedure. Given the published high reoperation rates in cervical spine surgery, these results in degenerative cervical myelopathy are not particularly surprising. In a recent minimum 10-year follow-up of anterior cervical fusion in 159 patients, Buttermann reported a 31% reoperation rate2. In the current study, Yick et al. confirm what smaller, short-term studies have suggested: improvement after decompression for degenerative cervical myelopathy is fleeting in many patients and reoperation is common. Such knowledge is valuable when counseling patients both before and after the surgical procedure. In addition to describing the neurological survivorship of these patients, Yick et al. drilled down on the risk factors for failure. Some of these significant risk factors are patient-specific and are not controllable by the surgeon. These factors include renal failure and spinal cord signal change on T2-weighted magnetic resonance imaging sequences. A cord signal change, associated with cellular changes in the cord secondary to severe cord compression, is often irreversible3 and, as seen in the current study, is associated with ongoing declines in neurological function. Other significant risk factors are modifiable. Surgeons can use these factors to modify their surgical management of cervical myelopathy and, hopefully, improve future neurological survivorship. First, and most importantly, surgeons should not be performing suture laminoplasty. Patients treated with this technique had the worst neurological survivorship (31.2%) and tended to experience treatment failure early after the surgical procedure. Second, patients with ossification of the posterior longitudinal ligament did best when decompression was combined with fusion. Surgeons should give strong consideration to including fusion in patients with ossification of the posterior longitudinal ligament to improve outcomes. Conversely, surgeons might consider avoidance of fusion in younger patients with cervical compressive myelopathy. The top risk factor for late neurological decline was adjacent-level stenosis, proximal or distal to a fusion construct. In these patients, perhaps a posterior decompression without fusion or a laminoplasty with plating will result in better neurological survivorship. Yick et al. should be commended for their efforts to publish longer-term neurological outcomes for this complex group of patients. The strengths of the study include a large cohort of 195 patients and a mean follow-up of 76 months. The weaknesses of the study include a retrospective design with many patients (49) excluded because of incomplete follow-up. Furthermore, many of the included patients (37) had a follow-up period shorter than 2 years. Nevertheless, Yick et al. identify important predictive factors for neurological survivorship after surgical treatment of degenerative cervical myelopathy and give surgeons specific pearls to help with surgical planning. A long-term prospective study with a minimum 10-year follow-up is still necessary to define optimal surgical approaches for degenerative cervical myelopathy.

Surgical Management of Cervical Myelopathy: Current Algorithm

Cervical myelopathy (CM) is a progressive disorder associated with a varied spectrum of etiological factors. Cervical spondylotic myelopathy (CSM) encompasses two-thirds of the cases of CM, while ossified posterior longitudinal ligament (OPLL) and ossified ligamentum flavum (OLF) are significant regional etiological factors. Microvascular disruption, resulting from repetitive dynamic compression or static pressure to the spinal cord, is attributed as a primary pathophysiological mechanism for CM. Magnetic resonance imaging (MRI) is the investigation of choice to assess the spinal cord. Lateral cervical radiographs are crucial for lordosis assessment, and tomographic scans (CT) can delineate the extent of OPLL and OLF. Non-surgical treatment is usually not successful once the patient develops progressive myelopathy. Anterior cervical procedures are ideal for one or two level disc-osteophytes complexes or in patients with kyphotic cervical alignment. Laminoplasty is an effective motion-preserving option in patients with adequate cervical lordosis. Laminectomy or laminoplasty and fusion are optimal for patients with significant preoperative neck pain. Posterior surgery is preferred over anterior surgery for CM involving three or more levels. Older age at presentation, longer duration of symptoms, and severity of pre-operative symptoms are adverse prognostic factors. Progressive cervical myelopathy is a surgical disease, and early intervention is rewarded with better outcomes. Keywords: Cervical myelopathy, Cervical spondylotic myelopathy, OPLL, OLF, Laminoplasty, Laminectomy, ACDF, Cervical corpectomy.

45. Trajectory of change in mJOA score within one year following surgery for degenerative cervical myelopathy

BACKGROUND CONTEXT Degenerative cervical myelopathy (DCM) is a progressive disease resulting from cervical cord compression. The natural progression of DCM is variable; some patients experience periods of stability, while others rapidly deteriorate following disease onset. The majority of these patients require surgical decompression to halt disease progression and improve functionality. The modified Japanese Orthopedic Association (mJOA) is a patient-reported questionnaire commonly used to grade symptoms and is a validated tool for assessment of postoperative improvement in the surgical management of cervical myelopathy. However, literature describing the natural history of recovery following surgical decompression is limited, especially in the postsurgical period of 3 to 12 months. PURPOSE The aim of the study is to assess the trajectory of mJOA improvement in the postsurgical period of 3 to 12 months in patients who underwent surgery for cervical myelopathy. STUDY DESIGN/SETTING This study is a retrospective analysis of prospectively collected data from the cervical module of a national spine registry, the Quality Outcomes Database (QOD). PATIENT SAMPLE A total of 2,156 patients who underwent elective surgery for DCM and had complete 3- and 12-month follow-up data in the QOD registry were included in the study. OUTCOME MEASURES The mJOA score was used to define severity of myelopathic symptoms in patients who underwent surgery for cervical myelopathy. METHODS Patients were divided into mild (≥14), moderate (9-13), or severe ( RESULTS Patients improved significantly from baseline to 3 months on their mJOA scores, regardless of their baseline mJOA severity. Four hundred five (18.8%) showed improvement during the time period of 3- to 12-month postsurgical follow-up. After adjusting for the relevant baseline patient and surgery specific characteristics, the baseline mJOA categories had significant impact on whether a patient improves by 2 points in mJOA score from 3- to 12-month postsurgery (75.49% of the total Wald X2, p CONCLUSIONS In the surgical management of cervical myelopathy, most patients achieve improvement on a shorter follow-up; however, patients with severe symptoms keep improving until after a longer follow-up. Preoperative identification of such patients helps the clinician with setting realistic expectations for each follow-up time point. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

275. The effect of the distal level or proximal level on post-laminoplasty loss of cervical vertebra lordosis

BACKGROUND CONTEXT Open-door laminoplasty is a useful operation in the surgical management of cervical myelopathy with favorable outcomes and relatively low complications. One potential undesirable outcome is a decrease in cervical lordosis postoperatively. It is unknown whether the most the distal level or proximal level undergoing laminoplasty affects the magnitude of loss of lordosis. PURPOSE This study aimed to compare the loss of cervical lordosis postoperatively in patients for whom the most proximal level undergoing laminoplasty is proximal level. STUDY DESIGN/SETTING A retrospective radiographic review as a center was carried out. PATIENT SAMPLE A total of 513 patients at a single institution who underwent plated open door laminoplasty for cervical myelopathy by multiple surgeons over a 5-year period were included. OUTCOME MEASURES The primary outcome was change in cervical lordosis, which was the difference in C2-T1 Cobb angle between the postoperative and preoperative film. METHODS Patients were divided into two groups based on the most proximal vertebral level undergoing laminoplasty. There were 157 patients who underwent laminoplasty beginning at C2, whereas 171 patients underwent laminoplasty beginning at C3, whereas 137 patients underwent laminoplasty beginning at C4, whereas 48 patients underwent laminoplasty beginning at C5. The C2-T1 Cobb angle was measured on the preoperative film and on the final postoperative follow-up film. The difference between these values was calculated for each patient, and the mean of the differences for the C3 group was compared with that of the C4 group. RESULTS When C2 was the proximal plated laminoplasty level, loss of lordosis averaged 12°. When C3 was the proximal plated laminoplasty level, loss of lordosis averaged 10°. When C4 was the proximal plated laminoplasty level, loss of lordosis averaged 4°. In contrast, when C5 was the proximal plated level, loss of lordosis was significantly less and averaged only 2° (p=0.041). In the group as a whole, mean preoperative lordosis was 21° compared with 12° postoperatively, for an overall 8° loss of lordosis. CONCLUSIONS Starting the laminoplasty at C4 led to significantly less loss of lordosis than starting at C2-C3. When the pattern of spinal cord compression does not require laminoplasty at C3, consideration should be given to making C4 the most cephalad laminoplasty level rather than C3 to better preserve lordosis. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Where should a laminoplasty start? The effect of the proximal level on post-laminoplasty loss of lordosis

Background ContextOpen-door laminoplasty is a useful operation in the surgical management of cervical myelopathy with favorable outcomes and relatively low complications. One potential undesirable outcome is a decrease in cervical lordosis postoperatively. It is unknown whether the most proximal level undergoing laminoplasty affects the magnitude of loss of lordosis. PurposeThis study aimed to compare the loss of cervical lordosis postoperatively in patients for whom the most proximal level undergoing laminoplasty is C3 versus C4. Study Design/SettingA retrospective radiographic review at an academic center was carried out. Patient SampleA total of 65 patients at a single institution who underwent plated open door laminoplasty for cervical myelopathy by multiple surgeons over a 5-year period were included. Outcome MeasuresThe primary outcome was change in cervical lordosis, which was the difference in C2–T1 Cobb angle between the postoperative and preoperative films. MethodsPatients were divided into two groups based on the most proximal vertebral level undergoing laminoplasty. There were 49 patients who underwent laminoplasty beginning at C3, whereas 16 patients underwent laminoplasty beginning at C4. The C2–T1 Cobb angle was measured on the preoperative film and on the final postoperative follow-up film. The difference between these values was calculated for each patient, and the mean of the differences for the C3 group was compared with that of the C4 group. ResultsWhen C3 was the proximal plated laminoplasty level, loss of lordosis averaged 9°. In contrast, when C4 was the proximal plated level, loss of lordosis was significantly less and averaged only 3° (p=.047). In the group as a whole, mean preoperative lordosis was 18° compared with 11° postoperatively, for an overall 7° loss of lordosis. ConclusionsStarting the laminoplasty at C4 led to significantly less loss of lordosis than starting at C3. When the pattern of spinal cord compression does not require laminoplasty at C3, consideration should be given to making C4 the most cephalad laminoplasty level rather than C3 to better preserve lordosis.

Surgical Management of Cervical Myelopathy: An Analysis of Patient Characteristics, Surgical Procedures, Complication Rates and Risk Factors

Surgical Management of Cervical Myelopathy: An Analysis of Patient Characteristics, Surgical Procedures, Complication Rates and Risk Factors

Regression of retroodontoid pseudotumors following C-1 laminoplasty

The authors report a new technique for C-1 laminoplasty without fusion in the treatment of cervical myelopathy associated with a retroodontoid pseudotumor (also known as a phantom tumor). The authors review the cases of three patients who underwent C-1 laminoplasty in which hydroxyapatite was used and fusion was not performed. All patients suffered from severe progressive myelopathy before surgery. Magnetic resonance imaging revealed a retroodontoid pseudotumor compressing the spinal cord at the C-1 level in all cases. Computed tomography was performed to examine the extent of bone erosion at the atlantoaxial joint and dens. Clinical parameters included neurological function, measured using the Japanese Orthopaedic Association score, and neck pain. Imaging parameters included pre- and postoperative atlas-dens intervals; the space available for the spinal cord; instability of the atlantoaxial joints; osteoarthritic changes of the atlantoaxial joint; postoperative changes in T2 high-intensity signal; and postoperative alteration in the size of the pseudotumor. Magnetic resonance imaging demonstrated complete disappearance of the pseudotumor in two cases and partial reduction in one case. In all three cases sufficient neurological recovery was observed. The mean recovery rate was 87.0%. This new technique is less invasive than standard procedures, preserves the cervical range of motion, and avoids the morbidity of obtaining a bone graft and placing instrumentation. The authors conclude that C-1 laminoplasty without fusion is an option in the surgical management of cervical myelopathy associated with a retroodontoid pseudotumor, either without C1-2 instability or with slight, but reducible, C1-2 instability.

Surgical management of cervical myelopathy: indications and techniques for surgical corpectomy

There are a variety of surgical treatments for cervical spondylotic myelopathy (CSM). Review the indications and techniques for multilevel cervical corpectomy in the treatment of CSM. Cervical corpectomy is effective and relatively safe for the treatment of a variety of diseases of the cervical spine. Indications, surgical considerations, operative positioning, surgical method, and complications avoidance are discussed as a guide to effectively performing this procedure.

Surgical management of cervical myelopathy: indications and techniques for multilevel cervical discectomy

Surgery is usually required for treatment of cervical myelopathy to decompress the neural elements, restore lordosis, and stabilize the spine. By addressing these problems, the neurological deterioration may be halted. Multilevel cervical discectomy and fusion offers several advantages over other approaches. The authors describe the technique, discuss the indications, and present the potential complications associated with it. Decompression is achieved via discectomy and subsequent removal of the osteophytes using a curetting technique. Preparation of end plates in a parallel fashion allows for gapless grafting of allograft bone for enhancement of fusion. A dynamic plate and screw system strengthens the construct. A high rate of fusion can be obtained using the technique of multilevel cervical discectomy and fusion with acceptable levels of complications. It is especially useful in cases of spondylosis that have a kyphotic deformity because, in addition to anterior decompression, it allows reconstruction of the spine to help restore a lordotic curvature. Multilevel cervical discectomy and fusion has proven to be very effective in decompressing and stabilizing the spine for treatment of cervical myelopathy.

Surgical management of cervical myelopathy dealing with the cervical–thoracic junction

The treatment of compressive cervical myelopathy is, in general, a surgical endeavor. Surgery involves decompression, often with an accompanying fusion with stabilization. The length of the fusion can vary and the decision regarding length of fusion is not always clear. This study explores the fundamental principles regarding the length of fusion at the cervicothoracic junction. A review of the literature regarding the anatomy and biomechanics of the cervicothoracic region is provided. Surgical approaches and indications for cervicothoracic junction region fusions are discussed. Fundamental guidelines for the decision-making process are provided. The cervicothoracic region is a biomechanically complex region. Although there is little biomechanical data indicating the appropriate length of fusion, several fundamental guidelines may be followed to reduce the incidence of construct failure. A long fusion should not end at an apical vertebra nor at the cervicothoracic junction. Long cervical fusions should be extended to traverse the cervicothoracic junction to a neutral vertebra.

Surgical management of cervical myelopathy: indications and techniques for laminectomy and fusion

Cervical spondylotic myelopathy (CSM) is a commonly encountered surgical disease that may be approached through a variety of operative techniques. Operative goals in the treatment of CSM include effective neural element decompression and maintaining spinal stability to avoid delayed deformity progression and neurologic compromise. Determining the most appropriate operative approach requires careful consideration of the patient's clinical presentation and radiographic imaging. To review the indications and techniques for multilevel laminectomy and fusion in the treatment of CSM. When indications permit, a multilevel laminectomy is an effective and safe method of neural element decompression. Recognizing the potential for spinal instability is essential to prevent neurologic compromise and intractable axial neck pain caused by deformity progression. A variety of techniques have been described to supplement the posterior tension band after laminectomy; however, lateral mass fixation has evolved into the preferred stabilization technique. Although clinical success is well documented, a successful outcome is dependent on a comprehensive, individualized evaluation of each patient presenting with CSM.