Selective blocking laminoplasty in cervical laminectomy and fusion to prevent postoperative C5 palsy

Effects of two posterior procedures for treatment of cervical hyperextension injury with multilevel spinal stenosis: A retrospective study

BACKGROUND

Cervical hyperextension injuries (CHI), commonly resulting in central cord syndrome and spinal instability, often affect the elderly with preexisting degenerative spinal changes, leading to a need for surgical interventions that address both the compression and stability of the cervical spine. This study compares the clinical outcomes of two posterior decompression and fixation procedures for treating cervical hyperextension injury in patients with preexisting multilevel spinal canal stenosis.

METHODS

Patients suffering from cervical hyperextension injury combined with multilevel spinal stenosis were divided into two groups. They received laminoplasty combined with selective unilateral pedicle screw fixation or laminectomy combined with bilateral lateral mass screw fixation. The clinical records including demographic data, operation time, length of hospital stay, estimated blood loss and surgical complications were collected, and clinical outcomes were evaluated using the American Spinal Injury Association (ASIA) impairment scale. Preoperative and postoperative cervical lordosis were measured.

RESULTS

Postoperative AISA scores were significantly increased compared with that before surgery in both groups, there was no significant differences between groups. The intraoperative blood loss in the laminoplasty group was significantly less than that in the laminectomy group and there were no significant differences in operation time and length of hospital stay between the two groups. No significant difference was found in the incidence of overall surgical complications between the two groups. There was no significant difference in the cervical lordosis after surgery compared with that before surgery in both groups.

CONCLUSIONS

For patients suffering from cervical hyperextension injury combined with preexisting multilevel spinal stenosis, both cervical laminoplasty with selective unilateral pedicle screw fixation and laminectomy with bilateral lateral mass screw fixation could achieve satisfactory clinical outcomes.

Comparison of Anterior Cervical Decompression and Fusion and Posterior Laminoplasty for Four-Segment Cervical Spondylotic Myelopathy: Clinical and Radiographic Outcomes

BACKGROUND

 Although anterior or posterior surgery for cervical spondylotic myelopathy (CSM) has been extensively studied, the choice of anterior or posterior approach in four-segment CSM remains poorly studied and controversial. We compared the clinical and radiographic outcomes of four-segment CSM by posterior laminoplasty (LAMP) and anterior cervical decompression fusion (ACDF) to further explore the merits and demerits of ACDF and LAMP for four-segment CSM in this study.

METHODS

 Patients with four-segment CSM who underwent ACDF or LAMP between January 2016 and June 2019 were retrospectively analyzed. We compared the preoperative and postoperative cervical Japanese Orthopaedic Association (JOA) scores, neck disability index (NDI), neck pain visual analog scale (VAS) score, sagittal vertical axis, cervical lordosis (CL), and range of motion.

RESULTS

 There were 47 and 79 patients in the ACDF and LAMP groups, respectively. Patients in the ACDF group had a significantly longer surgical time and lower estimated blood loss and length of stay than those in the LAMP group. There was no significant difference in the JOA, NDI, or neck pain VAS scores between the two groups preoperatively, but the NDI and neck pain VAS scores in the ACDF group were significantly lower than those in the LAMP group at the final follow-up. The preoperative C2-C7 Cobb angle of the ACDF group was significantly lower than that of the LAMP group but there was no significant difference between the two groups postoperatively. The improvement of C2-C7 Cobb angle (∆C2-C7 Cobb angle) in the ACDF group was significantly higher than that in the LAMP group. This indicated that ACDF can improve CL better than LAMP. The linear regression analysis revealed the ∆C2-C7 Cobb angle was negatively correlated with the final follow-up neck pain VAS scores and NDI. This indicated that patients with better improvement of CL may have a better prognosis.

CONCLUSIONS

 Although both ACDF and LAMP surgeries are effective for four-segment CSM, ACDF can better improve CL and neck pain. For patients with poor CL, we suggest ACDF when both approaches are feasible.

Comparison of Anterior Cervical Discectomy and Fusion with Cervical Laminectomy and Fusion in the Treatment of 4-Level Cervical Spondylotic Myelopathy

Objective

To assess and compare the therapeutic effects of Anterior Cervical Discectomy and Fusion (ACDF) and Cervical Laminectomy and Fusion (CLF) in the treatment of 4‐level cervical.

Methods

We performed a retrospective review on 39 patients with 4‐level CSM who underwent ACDF or CLF in the Third Hospital of Hebei Medical University from January 2010 to December 2018. The patients were divided into ACDF group and CLF group according to the treatment. The operative index was evaluated based on intraoperative blood loss and operation time. The functional outcomes including Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) of axial pain were compared. The Cobb angle, Cobb angle improvement rate, range of motion (ROM) and ROM loss ratio were measured for radiographic evaluation.

Results

No major complications or deaths occurred. The average age at baseline was 55 years. There was no significant difference between the ACDF and CLF group in follow‐up time (26.29 months, 25.39 months, P > 0.05). The intraoperative blood loss was higher in the CLF group than in the ACDF group (692.67 ± 38.68 vs 392.14 ± 128.06, P < 0.05). The operation time was longer in the CLF group than in the ACDF group (206.60 ± 49.37 vs 172.64 ± 31.96, P < 0.05). Significant improvements in the VAS and JOA scores were observed in both groups (P < 0.05). No significant difference in VAS was found between the ACDF and CLF groups (P < 0.05). There was a significantly larger improvement rate of JOA score in the ACDF group than in the CLF group (60.9% ± 9.57% vs 31.5% ± 15.70%, P < 0.05). There were two (9.6%) cases with complications In the ACDF group, including one (4.8%) case of dysphagia and one (4.8%) case of pharyngodynia. In the CLF group, two patients (11.1%) developed C₅ palsy. No significant difference in the incidence of complications, ROM loss ratio and Cobb angle improvement rate was found between group ACDF and group CLF (all P < 0.05).

Conclusion

Both ACDF and CLF were effective in the treatment of multi‐level cervical spondylosis and ACDF is more suitable for patients with 4‐level CSM.

Relationship between cervical curvature and spinal cord drift distance after laminectomy via lateral mass screw fixation and its effect on clinical efficacy

BACKGROUND

Laminectomy with lateral mass screw fixation (LCS) is considered an effective surgical procedure for cervical spondylotic myelopathy. However, varying degrees of loss of the cervical curvature were noted in some patients postoperatively. The aim of this study was to observe the relationship between cervical curvature and spinal drift distance after LCS and to determine its effect on neurological function, axial symptoms, and C5 palsy.

METHODS

A total of 117 consecutive cervical spondylotic myelopathy patients with normal cervical curvature underwent LCS from April 2015 to May 2017 in our institution. Of these patients, 90 patients who accepted to undergo an integrated follow-up were enrolled in this study. The patients were divided into 3 groups based on their postoperative cervical curvature. In group A (28 patients), the cervical curvature became straight postoperatively (0°≤cervical spine angle≤5°); in group B (36 patients), the cervical curvature decreased (5°<cervical spine angle≤16.5°); and in group C (26 patients), the cervical curvature remained normal (cervical spine angle>16.5°). Spinal drift distance, neurological recovery, axial symptoms, and C5 palsy in the patients were recorded and analyzed.

RESULTS

Postoperative measurements showed that there was no significant difference in laminectomy width between the groups (P > .05). The cervical spine angle was 2.7° ± 0.5° in group A, 11.2° ± 2.6° in group B, and 20.8° ± 4.1° in group C (P < .05), while the spinal drift distance was 1.2 ± 0.2 mm, 1.8 ± 0.4 mm, and 3.0 ± 0.5 mm, respectively (P < .05). The postoperative Japanese Orthopedic Association score was significantly increased in all groups (P < .05), and there was no significant difference between the groups at different time points (P > .05). However, significant differences were noted between the groups in axial symptoms (P < .05), which were analyzed via the visual analog scale score. The occurrence of C5 palsy in groups A, B, and C was 7.1% (2/28), 8.3% (3/36), and 11.5% (3/26), respectively (P > .05).

CONCLUSION

In LCS, the cervical curvature should be maintained at the normal angle to obtain a good spinal cord drift distance and a lower incidence of axial symptoms.

Preoperative electrophysiologic assessment of C5-innervated muscles in predicting C5 palsy after posterior cervical decompression

PURPOSE

To investigate the feasibility of both needle electromyography (EMG) and proximal nerve conduction studies (NCS) in predicting C5 palsy after posterior cervical decompression.

METHODS

This study included 192 patients with cervical myelopathy undergoing laminoplasty or laminectomy. Preoperatively, all patients accepted bilateral needle EMG detection and proximal NCS that consisted of supramaximally stimulating Erb's point and recording compound muscle action potential (CMAP) from bilateral deltoid.

RESULTS

In the present study, 11 (11/192, 5.7%) patients developed unilateral C5 palsy after operation, and more patients with C5 palsy showed abnormal spontaneous activity in C5-innervated muscles compared to those without C5 palsy (8/11 vs. 16/181, p < 0.05). The sensitivity and specificity of spontaneous activity in C5-innervated muscles in predicting postoperative C5 palsy were 72.7% and 91.2%, respectively. Furthermore, there were significant left-to-right differences of deltoid CMAP amplitudes between the patients with and without C5 palsy (p < 0.05), and this measurement was also demonstrated to be useful for distinguishing patients with C5 palsy from cases without C5 palsy by receiver operating characteristic (ROC) curve analysis (cut-off value: 2.1 mV, sensitivity: 63.6%; specificity: 95.0%). In addition, the sensitivity and specificity of a series application of these two measurements were 63.6% and 100.0%, respectively.

CONCLUSIONS

The findings of this study support the hypothesis that pre-existing progressive C5 root injury may be a risk factor for C5 palsy after posterior cervical decompression. Clinically, the estimation of NCS and needle EMG in C5-innervated muscles may provide additional useful information for predicting C5 palsy after cervical spinal surgery.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Complications following posterior cervical decompression and fusion: a review of incidence, risk factors, and prevention strategies

Posterior cervical decompression and fusion (PCF) is a common surgical technique used to treat various cervical spine pathologies. However, there are various complications associated with PCF that can negatively impact patient outcome. We performed a comprehensive literature review to identify the most common complications following PCF using PubMed, Cochrane Database of Systematic Reviews, and Google Scholar. The overall complication rates of PCF are estimated to range from about 15% to 25% in the current literature. The most common immediate complications include acute blood loss anemia, surgical site infection (SSI), C5 palsy, and incidental durotomy; the most common long-term complications include adjacent segment degeneration, junctional kyphosis, and pseudoarthrosis. Three principal mechanisms are thought to contribute to complications. First, higher number of fusion levels, obesity, and more complex pathologies can increase the invasiveness of the planned procedure, thus increase complications. Second, wound healing and arthrodesis may be impaired due to poor blood flow due to various patient factors such as smoking, diabetes, increased frailty, steroid use, and other medical comorbidities. Finally, increased biomechanical stress on the upper instrumented vertebra (UIV) and lowest instrumented vertebra (LIV) may predispose patient to chronic degeneration and result in adjacent level degeneration and/or junctional problems. Reducing the modifiable risk factors pre-operatively can decrease the overall complication rate. Neurologic deficits may be reduced with adequate intraoperative decompression of neural elements. SSI may be reduced with meticulous wound closure that minimizes dead space, drain placement, and the use of intra-wound antibiotics. Careful design of the fusion construct with consideration in spinal alignment and biomechanics can help to reduce the rate of junctional problems. Spine surgeons should be aware of these complications associated with PCF and the corresponding prevention strategies optimize patient outcomes.

Differential Analysis of the Spinal Cord Shift After Laminoplasty With Upper Extension to the C2 Segment and Conventional Surgery of the C3-C7 Segments

STUDY DESIGN

A retrospective controlled study.

OBJECTIVE

To clarify the differences of spinal cord shift between laminoplasty with extension to the C2 segment and conventional surgery of the C3-C7 segments.

SUMMARY OF BACKGROUND DATA

For patients of spinal cord compression at C2/C3 or C2, it is difficult to achieve decompression involving only the C3-C7 segments. Therefore, a laminoplasty with upper extension to C2 is needed. Nevertheless, there is not yet a definitive conclusion regarding whether laminoplasty with extension to C2 can achieve a better spinal cord shift than an extension of the C3-C7 segments.

MATERIALS AND METHODS

Preoperative and final follow-up Japanese Orthopedic Association scores were recorded. MRI T2 patient images before and after surgery were used for data collection. The anterior subarachnoid spaces, spinal cord diameters, posterior subarachnoid spaces, and dural sac diameters were measured. The distance of spinal cord shift in a single plane was represented by the differences in the sum of the anterior subarachnoid spaces and the spinal cord diameters before and after surgery. The overall distances and distances of each segment backward were compared between the C2-C7 group and the C3-C7 group. All planes were also classified as segments with compression or noncompression, and the differences in backward shift were compared.

RESULTS

There were no significant differences in Japanese Orthopedic Association score between the C2-C7 and C3-C7 groups at final follow-up and no significant differences in the overall backward shift between the 2 groups. The spinal cord shift of C1, C2, and C2/C3 segments and the segment of the largest shift distance were significantly different between the 2 groups; the spinal cord shift of the segments under compression was larger than that of noncompression.

CONCLUSIONS

Surgery with upper extension to the C2 segment did not increase the overall spinal cord shift; instead, a better effect was achieved by the effective decompression of local compressed segments, thus obtaining an effective expansion and shift of the spinal cord.

LEVELS OF EVIDENCE

Level II.