Posterior Laminectomy and Lateral Mass Screw Fixation for the Treatment of Severe Cervical Spondylotic Myelopathy

Background Severe and complex cervical spondylotic myelopathy(CSM) requires surgical treatment. The common methods of posterior cervical spine surgery are laminoplasty and laminectomy with lateral mass screw internal fixation. However, the operative effect of this surgical approach is unclear owing to the complexity and severity of CSM in patients who undergo this surgical treatment.Therefore, we aimed to evaluate the clinical effects of posterior cervical laminectomy and lateral mass screw internal fixation in patients with severe and complex CSM. Methods We retrospectively analysed 60patients (48men,12women; mean age59.7 years) with severe and complex CSM who underwent posterior cervical laminectomy and lateral mass screw internal fixation from May 2013 to June 2020. Forty-eight patients underwent laminectomy and lateral mass screw internal fixation;12 patients underwent laminectomy and lateral mass screw internal fixation with 1–2 segmental laminoplasty. C-spine radiographs, computed tomography (CT) scans, and magnetic resonance imaging (MRI) were used to detect any curvature and fusion of the cervical spine, restenosis, and loose/broken internal fixation screws.Clinical efficacy was evaluated using Japanese Orthopaedic Association (JOA)scores, neck disability index(NDI), Odom’s classification, and the visual analogue scale(VAS) for pain. Results Overall effect was satisfactory at the last follow-up (average, 3.6 years [range, 6 months–6 years]), with no restenosis or loosened, slipped, or broken internal fixations. The anterior curvature angle of lordosis (n=46)was not significantly different from baseline at the last follow-up(P>0.05). The cervical kyphosis angle (n=14)was significantly improved at the last follow-up compared with the baseline value (P<0.05), as were the JOA, NDI, and VAS scores(all P<0.05). Odom’s classifications at the last follow-up were excellent, good, and fair in 45, 12, and three patients, respectively. Conclusions Posterior cervical laminectomy and lateral mass screw internal fixation achieved satisfactory clinical results in severe and complex CSM cases.Combining this surgical method with laminoplasty of 1–2 spinal segments stabilised the cervical spine and provided spinal decompression while preventing excessive backward drift of the cervical spinal cord, resulting in fewer complications.

Morphometric Anatomy of the Posterior Aspect of the Atlas and the Vertebral Artery Groove in Relation to Lateral Mass Screw Placement

Background Atlantoaxial instability is an important disorder that causes serious symptoms such as difficulties in walking, limited neck mobility, sensory deficits, etc. Atlantal lateral mass screw fixation is a surgical technique that has gained important recognition and popularity. Because accurate drilling area for screw placement is of utmost importance for a successful surgery, we aimed to investigate morphometry of especially the posterior part of C1. Methods One hundred and fifty-eight human adult C1 dried vertebrae were obtained. Measurements were performed directly on dry atlas vertebrae, and all parameters were measured by using a digital caliper accurate to 0.01 mm for linear measurements. Results The mean distance between the tip of the posterior arch and the medial inner edge of the groove was found to be 10.59 ± 2.26 and 10.49 ± 2.20 mm on the right and left, respectively. The mean distance between the tip of the posterior arch and the anterolateral outer edge of the groove was 21.27 ± 2.28 mm (right: 20.96 ± 2.22 mm; left: 21.32 ± 2.27 mm). The mean height of the screw entry zone on the right and left sides, respectively, were 3.86 ± 0.81 and 3.84 ± 0.77 mm. The mean width of the screw entry zone on both sides was 13.15 ± 1.17 and 13.25 ± 1.3 mm. Conclusion Our result provided the literature with a detailed database for the morphometry of C1, especially in relation to the vertebral artery groove. We believe that the data in the present study can help surgeons to adopt a more accurate approach in terms of accurate lateral mass screw placement in atlantoaxial instability.

Surgical Treatment of Multilevel Degenerative Cervical Myelopathy: Open-Door Laminoplasty and Fixation via Unilateral Approach. A Feasibility Study

Objective We compared open-door laminoplasty via a unilateral approach and additional unilateral lateral mass screw fixation (uLP) with laminectomy and bilateral lateral mass screw fixation (LC) in the surgical treatment of multilevel degenerative cervical myelopathy (mDCM). Methods A retrospective cohort analysis of 46 prospectively enrolled patients (23 uLP and 23 LC). The minimum follow-up was 1 year. Neck and arm pains were evaluated with visual analog scales and disability with the Neck Disability Index (NDI). Myelopathy was rated with the modified Japanese Orthopaedic Association (mJOA) score. Cervical sagittal parameters were measured on plain and functional X-ray films with a specific software. The statistical significance was set at p < 0.05. Fusion was defined as <2 degrees of intersegmental motion on flexion/extension radiographs. Results The two groups were similar in age and comorbidities. The mean operation time and the mean hospital stay were shorter in the uLP group (p = 0.015). The intraoperative blood loss did not exceed 200 mL in both groups. At follow-up, the groups showed comparable clinical outcome data. The sagittal profile did not deteriorate in either group. Fusion rates were 67% in the uLP group and 92% in the LC group. No infections occurred in either group. In the LC group, one patient developed a transient C5 palsy. Revision surgery was required for a malpositioned screw (LC) and for one implant failure (uLP). Conclusion Laminoplasty and unilateral fixation via a unilateral approach achieved comparable clinical and radiologic results with laminectomy and bilateral fixation, despite a lower fusion rate. However, the surgical traumatization was less.

Efficacy of Posterior Cervical Laminectomy and Decompression plus Lateral Mass Screw-Rod Internal Fixation in the Treatment of Multisegment Cervical Spinal Canal Stenosis and Effects on Cervical Curvature and Range of Motion Parameters

Objective. To investigate the clinical effects of posterior laminectomy and decompression plus lateral mass screw-rod internal fixation for the treatment of multisegment cervical spinal canal stenosis and the improvement of cervical curvature and range of motion in patients. Methods. A total of 68 patients with multisegment cervical spinal stenosis who were treated in our hospital from January 2019 to June 2020 were selected and randomly divided into the control group and the observation group according to the random number table, with 34 patients in each group. The patients in the control group were treated with traditional posterior cervical open-door laminoplasty with silk suture fixation, while those in the observation group were treated with posterior cervical laminectomy and decompression plus lateral mass screw-rod internal fixation. The perioperative index of patients in the two groups was recorded, and the clinical efficacy of patients was evaluated. The patient’s JOA score, cervical physiological curvature, and cervical range of motion were evaluated. The occurrence of complications was recorded during follow-up. Results. The amount of intraoperative bleeding and postoperative rehabilitation training time in the observation group was less than that in the control group ( P < 0.05 ). There was no significant difference in operation time between the two groups ( P > 0.05 ). The total effective rate of the observation group was significantly higher than that of the control group ( P < 0.05 ). The JOA scores at 1 week, 6 months, and 12 months after operation in the observation group were higher than those in the control group ( P < 0.05 ). The physiological curvature of cervical spine in the observation group at 1 week, 6 months, and 12 months after operation was higher than that in the control group ( P < 0.05 ). The cervical range of motion at 12 months after operation in the observation group was significantly higher than that in the control group ( P < 0.05 ). The incidence of postoperative complications in patients of the observation group was significantly lower than that of the control group ( P < 0.05 ). Conclusion. Posterior laminectomy and decompression plus lateral mass screw-rod internal fixation can help patients to improve various clinical symptoms caused by nerve compression and obtain better improvement of cervical curvature and range of motion. It is an ideal surgical method for the treatment of multisegment cervical spinal canal stenosis, and it is conducive to improving the clinical efficacy of patients.

Relationship of Change in Cervical Curvature after Laminectomy with Lateral Mass Screw Fixation to Spinal Cord Shift and Clinical Efficacy

Background and Study Aims Although laminectomy with lateral mass screw fixation (LCSF) is an effective surgical treatment for cervical spondylotic myelopathy (CSM), loss of cervical curvature may result. This study aimed to investigate the effect of cervical curvature on spinal cord drift distance and clinical efficacy. Patients and Methods We retrospectively analyzed 78 consecutive CSM patients with normal cervical curvature who underwent LCSF. Cervical curvature was measured according to Borden's method 6 months after surgery. Study patients were divided into two groups: group A, reduced cervical curvature (cervical lordosis depth 0–7mm; n = 42); and group B, normal cervical curvature (cervical lordosis depth 7–17mm; n = 36). Spinal cord drift distance, laminectomy width, neurologic functional recovery, axial symptom (AS) severity, and incidence of C5 palsy were measured and compared. Results Cervical lordosis depth was 5.1 ± 1.2 mm in group A and 12.3 ± 2.4 mm in group B (p < 0.05). Laminectomy width was 21.5 ± 2.6 mm in group A and 21.9 ± 2.8 mm in group B (p > 0.05). Spinal cord drift distance was significantly shorter in group A (1.9 ± 0.4 vs. 2.6 ± 0.7 mm; p < 0.05). The Japanese Orthopaedic Association (JOA) score significantly increased after surgery in both groups (p < 0.05). Neurologic recovery rate did not differ between the two groups (61.5 vs. 62.7%; p > 0.05). AS severity was significantly higher in group A (p < 0.05). C5 palsy occurred in three group A patients (7.1%) and four group B patients (11.1%), but the difference was not significant (p > 0.05). Conclusion After LCSF, 53.8% of the patients developed loss of cervical curvature. A smaller cervical curvature resulted in a shorter spinal cord drift distance. Loss of cervical curvature was related to AS severity but not improvement of neurologic function or incidence of C5 palsy.

PROGNOSTIC OUTCOME IN SUBAXIAL CERVICAL SPINE INJURIES MANAGEMENT BY ANTERIOR CERVICAL DYNAMIC PLATE WITH CAGE/GRAFT FIXATION AND POSTERIOR CERVICAL LATERAL MASS SCREW-ROD FIXATION METHODS

Introduction: The anterior cervical decompression and fusion (ACDF)procedures, especially in cases requiring decompression of two or more levels. Routine use for the treatment of cervical spondylosis has caused plate design to change signicantly in recent years. Aim: To estimate the incidence of sub axial cervical trauma patients admitted in the Neurosurgery wards of the institute. To study the therapeutic outcome after management of the subaxial cervical trauma cases by Anterior cervical decompression (discectomy/corpectomy) with graft or cage and dynamic plate xation, posterior lateral mass screw-rod xation, bidirectional single stage combined approach techniques. To compare anterior dynamic plate graft xation with the posterior lateral mass screw rod xation in cases that could be managed by any single approach. Material and methods: This non randomized prospective observational study was conducted in the Department of Neurosurgery, Mahatma Gandhi Medical College & Hospital, Jaipurfrom April 2018 to December 2019. All diagnosed cases of subaxial cervical spine attending and being admitted to our institute during the study period and treated by anterior cervical decompression with dynamic plate xation, posterior lateral mass screw rod xation or combined technique were included in the study. Result:According to AO Spine Classication Type, 10(20.8%) patients had A2, 15(31.3%) patients had A3, 8(16.7%) patients had A4, 1(2.1%) patient had B2, 13(27.1%) patients had C and 1(2.1%) patient had C,F4. It was found that in Non Severe group, 6(31.6%) patients had A3type in AO Spine Classication Type and in severe group 9(31.0%) patients had A3type in AO Spine Classication Type. In Non Severe group, 4(21.1%) patients had C type in AO Spine Classication Type and in Severe group 9(31.0%) patients had C type in AO Spine Classication Type. The association between AO Spine Classication Type vs ASIAImpairment Scale Group was not statically signicant (p=0.6887). Conclusion:In ASIA IMPAIRMENT SCALE GROUP, 5 SLICS1 was higher [6(31.6%)] in Non Severe group and 8 SLICS1 was higher [9(31.0%)] in Severe group which was not statically signicant (p=0.4820).The mean EQ5D post op at 6month of Non Severe (ASIA IMPAIRMENTSCALE) patients was higher than the Severe group of patients which wasstatically signicant (p=0.0442).