Epidemiology of C5 Palsy after Cervical Spine Surgery: A 21-Center Study

Biceps involvement and degree of motor deficit at diagnosis are independently predictive of timing of postoperative C5 palsy recovery

BACKGROUND CONTEXT

C5 palsy is a debilitating complication following cervical spine surgery. This is the largest single-institution study evaluating C5 palsy and is specifically aimed at risk factors predictive of recovery timing.

PURPOSE

To assess the impact of demographic, radiographic, and surgical factors on C5 palsy recovery timing.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Adult patients with postoperative C5 palsy following anterior cervical discectomy and fusion (ACDF), posterior cervical decompression and fusion (PCDF), combined ACDF/PCDF, or laminoplasty between 2010 and 2023.

OUTCOME MEASURES

C5 palsy recovery at 6 months and 1 year after surgery, postoperative opioid consumption, cervical alignment measurements including (1) C2-C7 cobb angle, (2) C2-C7 sagittal vertical axis, (3) C2 slope, (4) C2 tilt, and (5) T1slope.

METHODS

Demographics, surgical and radiographic variables were recorded. Patients were divided based on resolution of symptoms to the level of their preoperative strength versus persistence of symptoms at 6 months and 1 year after surgery. Appropriate statistical analysis was performed with alpha <0.05.

RESULTS

93 patients had postoperative C5 palsy (63-PCDF, 21-ACDF, 6-ACDF/PCDF, 3-laminoplasty). Patients whose C5 palsy persisted at 6 months were more likely to be male, older, and have higher Charlson Comorbidity Index. At 1 year, those with persistent symptoms were demographically similar to those with resolution. Preoperative radiographic variables (C2-C7 Cobb angle and SVA, C2 tilt and slope, and T1 slope) were not associated with recovery timing at either timepoint. Multivariable logistic regression identified biceps involvement at C5 palsy diagnosis as independently predictive of persistence of symptoms at 6 months, and degree of both biceps and deltoid weakness as predictive at both timepoints (6 months: odd ratio=1.92; p=0.005; 1 year: estimate-1.90; p=0.011). 71% of all patients recovered within 1 year.

CONCLUSIONS

The presence of biceps involvement independently predicted persistence of C5 palsy at 6 months. The severity of biceps and deltoid motor deficit independently predicted persistence of C5 palsy both timepoints. Identifying these risk factors can help to inform patient counseling regarding the recovery dynamics of C5 palsy.

Increased Change in Cervical Lordosis Is Associated With Decreased Rate of Recovery in Patients With C5 Palsy

STUDY DESIGN

A retrospective chart review.

OBJECTIVE

The authors aim to investigate the role of clinical and radiographic parameters in patients who underwent posterior cervical surgery, and their association with C5 palsy severity and time to recovery.

BACKGROUND

Postoperative C5 palsy affects 1%-30% of patients undergoing posterior decompression, with or without fusion. Causation and avoidance of this complication remain widely debated.

MATERIALS AND METHODS

A single institution review of patients who underwent posterior cervical spine surgery was focused on using specific Common Procedural Technology codes associated with the patient population of interest. Patients were excluded if they had inadequate pre and postoperative imaging, as well as a history of prior cervical spine surgery, concurrent anterior surgery, intradural pathology, spinal tumor, or spinal trauma. Radiographic measurements of the pre and postoperative images were completed with subsequent intraclass correlation coefficient analysis to confirm the precision of measurements.

RESULTS

Out of 105 total patients, 35 (33%) patients developed a C5 palsy. Twenty-four (69%) of those palsies completely resolved, with a median time to recovery of 8 months. Preoperative demographics and radiographic parameters demonstrated heterogeneity among those patients who did and did not have a resolution of palsy. Patients with increased change in C2-C7 lordosis ( P = 0.011) after surgery were associated with decreased likelihood of recovery. Patients without a smoking history ( P = 0.009) had an increased likelihood of recovering from C5 palsy.

CONCLUSIONS

The degree of increased lordosis in the treatment of degenerative cervical disease plays a role in the rate of recovery from C5 palsy. This should be considered during preoperative planning in determining the amount of lordosis desired. In addition, patients without a smoking history were associated with a higher rate of recovery.

LEVEL OF EVIDENCE

Level IV.

Phrenic Nerve Palsy After Posterior Cervical Fusion: A Case Report and Review of Literature

INTRODUCTION

Cervical nerve palsies, most commonly C5, are relatively common following posterior cervical decompression and fusion (PCDF) for the management of cervical myelopathy. However, phrenic nerve palsy following PCDF is a rare complication documented in only one previous case report. The authors present a case of phrenic nerve palsy following PCDF.

METHODS AND MATERIAL

The patient is a 51-year-old male who presented with cervical myelopathy and radiculopathy as well as cervicalgia of 1 year's duration. The patient underwent C3-C6 posterior cervical decompression and fusion (PCDF). On postoperative day 5, he was found to have a right C5 nerve palsy, which improved with steroid use and physical therapy. When he returned at 7 weeks postoperatively, the patient had progressive dyspnea. A fluoroscopic exam by pulmonology revealed a right-sided phrenic nerve palsy was the cause of the dyspnea.

RESULTS AND DISCUSSION

Phrenic nerve palsy causing hemi-diaphragmatic paralysis is a rare complication of cervical spine surgery that requires a high degree of suspicion due to the nonspecific signs and symptoms. Our clinical case suggests that surgeons should bear in mind phrenic nerve palsy as a potential complication in patients with respiratory distress following cervical laminectomy.

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.

A systematic review of risk factors and adverse outcomes associated with anterior cervical discectomy and fusion surgery over the past decade

Background

Anterior cervical discectomy and fusion (ACDF) is one of the most frequently performed cervical surgeries in the world, yet there have been several reported complications.

Objective

To determine the actual incidence of complications related to ACDF as well as any risk variables that may have been identified in earlier research.

Methods

To evaluate the origin, presentation, natural history, and management of the risks and the complications, we conducted a thorough assessment of the pertinent literature. An evaluation of clinical trials and case studies of patients who experienced one or more complications following ACDF surgery was done using a PubMed, Cochrane Library, and Google Scholar search. Studies involving adult human subjects that were written in the English language and published between 2012 and 2022 were included in the search. The search yielded 79 studies meeting our criteria.

Results

The overall rates of complications were as follows: Dysphagia 7.9%, psudarthrosis 5.8%, adjacent segment disease (ASD) 8.8%, esophageal perforations (EPs) 0.5%, graft or hardware failure 2.2%, infection 0.3%, recurrent laryngeal nerve palsy 1.7%, cerebrospinal fluid leak 0.8%, Horner syndrome 0.5%, hematoma 0.8%, and C5 palsy 1.9%.

Conclusion

Results showed that dysphagia was a common postoperative sequelae with bone morphogenetic protein use and a higher number of surgical levels being the major risk factors. Pseudarthrosis rates varied depending on the factors such as asymptomatic radiographic graft sinking, neck pain, or radiculopathy necessitating revision surgery. The incidence of ASD indicated no data to support anterior cervical plating as more effective than standalone ACDF. EP was rare but frequently fatal, with no correlation found between patient age, sex, body mass index, operation time, or number of levels.

Management of Cerebrospinal Fluid Leakage by Pump-Regulated Volumetric Continuous Lumbar Drainage Following Anterior Cervical Decompression and Fusion for Ossification of the Posterior Longitudinal Ligament

OBJECTIVE

Cerebrospinal fluid (CSF) leakage is a major concern related to anterior cervical decompression and fusion for ossification of the posterior longitudinal ligament (OPLL). We propose a management algorithm for CSF leakage following anterior cervical decompression and fusion for OPLL involving the use of pump-regulated volumetric continuous lumbar drainage.

METHODS

We retrospectively reviewed patients who underwent anterior cervical decompression and fusion for OPLL and were managed with the proposed algorithm between March 2018 and July 2022. The proposed management algorithm for CSF leakage by pump-regulated volumetric continuous lumbar drainage was as follows. On exposure of the arachnoid membrane with or without CSF leakage, a dural sealant patch was applied to manage the dural defect. In case of persistent CSF leakage despite application of the dural sealant patch, patients underwent pump-regulated volumetric continuous lumbar drainage.

RESULTS

Fifty-one patients were included in the study. CSF leakage occurred in 14 patients. Of these 14 patients, 9 patients underwent lumbar drain insertion according to the proposed management algorithm. Successful resolution of CSF leakage was observed in 8 of the 9 patients who underwent lumbar drainage. All patients were encouraged to ambulate without concern of CSF overdrainage due to gravity, because it could be avoided with pump-regulated volumetric continuous CSF drainage. Therefore, complications associated with absolute bed rest or CSF overdrainage were not observed.

CONCLUSION

The proposed management algorithm with pump-regulated volumetric continuous lumbar drainage showed safety and efficacy for management of CSF leakage following anterior decompression and fusion for OPLL.

Bilateral phrenic nerve palsy after posterior cervical decompression and fusion surgery: a rare event after surgery

INTRODUCTION

Delayed C5 weakness is a known entity in cervical spine surgery, although with varied clinical presentation and poorly understood mechanism of action. We describe the first case in the literature of a bilateral C5 palsy leading to bilateral phrenic nerve dysfunction following a posterior cervical decompression and fusion.

CASE REPORT

A 76-year-old male presented with low back pain and was diagnosed as myelopathic. On initial neurological examination, he could not ambulate without assistance and was unsteady on tandem gait. The initial cervical MRI and CT scan showed advanced multilevel degenerative changes of the cervical spine with severe cord compression and myelomalacia. The patient underwent C3-C6 posterior cervical decompression & fusion (PCDF). He awoke with his baseline examination without neurophysiological monitoring changes intraoperatively or C5 root EMG activity. Post-operative MRI of the cervical spine was performed and showed an excellent decompression. The patient was neurologically stable and discharged to a rehabilitation facility. Patient developed a delayed bilateral C5P on postoperative day (POD) 74. Delayed bilateral C5P and phrenic nerve damage was determined to cause this patient's dyspnea. PM&R consult recommended placement of diaphragmatic pacers. However, clinically his respiratory function, as well as motor deficits, have gradually improved.

CONCLUSION

Bilateral diaphragmatic paralysis, a severe complication of cervical spine surgery, may cause respiratory distress and upper limb weakness. C5P, the underlying cause, may arise from various factors. Early detection and management of diaphragmatic weakness with physical therapy and pacers are crucial, emphasizing the need for vigilance by healthcare professionals and surgeons.

Clinical Spectrum of Postsurgical Parsonage-Turner Syndrome: A Perspective From an Electrodiagnostic Laboratory

BACKGROUND

Parsonage-Turner syndrome (PTS) is an underdiagnosed disorder characterized by the acute onset of severe pain in the shoulder/scapula/arm followed by muscle weakness/numbness in the distribution of nerves derived from the brachial plexus (BP). Surgical procedures are one of several antecedent events of PTS. This study describes the clinical spectrum of postsurgical Parsonage-Turner syndrome (PSPTS) in a large cohort of patients.

MATERIALS AND METHODS

Charts of patients diagnosed with PTS during a 16-year (2006-2022) retrospective review were analyzed to identify cases of PSPTS. The clinical criteria for PSPTS included the new onset of severe pain two days to four weeks after a surgical procedure followed by weakness of muscles innervated by one or more nerves arising from the BP. EDX criteria consist of denervation localized to branches of the BP. PSPTS cases were subdivided into two categories: definite PSPTS (surgery at a remote site) and probable PSPTS (surgery of the ipsilateral upper extremity or the cervical spine).

RESULTS

Of 202 patients (204 episodes) diagnosed with PTS, 111 (54%) were idiopathic and 61 (30%) were PSPTS. Of the 61 PSPTS episodes, 26 were definite and 35 were probable PSPTS. The anterior interosseous nerve (AIN) was most affected, followed by the posterior interosseous (PIN), and suprascapular nerve.

CONCLUSION

In this series, surgery was the most commonly recognized antecedent event for PTS, and the AIN and PIN were the most frequent nerves affected. Surgeons should consider PTS in patients who develop postoperative severe shoulder pain and weakness of muscles innervated by the BP.

Posterior Preventive Foraminotomy before Laminectomy Combined with Pedicle Screw Fixation May Decrease the Incidence of C5 Palsy in Complex Cervical Spine Surgery in Patients with Severe Myeloradiculopathy

C5 palsy is a frequent sequela of cervical decompression surgeries for cervical myeloradiculopathy. Although many researchers have suggested various risk factors, such as cord shifting and the correction of lordotic angles, the tethering of the C5 root beneath the narrow foramen is an independent risk factor for C5 palsy. In this study, we tried to investigate different techniques for foramen decompression with posterior cervical fusion and assess the incidence of C5 palsy with each technique depending on the order of foraminal decompression. A combined 540° approach with LMS and uncovertebrectomy was used in group 1. Group 2 combined a 540° approach with pedicle screws and posterior foraminotomy, while posterior approach only with pedicle screws and foraminotomy was used in group 3. For groups 2 and 3, prophylactic posterior foraminotomy was performed before laminectomy. Motor manual testing to assess C5 palsy, the Neck Disability Index (NDI) and the Japanese Orthopedic Association (JOA) scores were determined before and after surgery. Simple radiographs, MRI and CT scans, were obtained to assess radiologic parameters preoperatively and postoperatively. A total of 362 patients were enrolled in this study: 208 in group 1, 72 in group 2, and 82 in group 3. The mean age was 63.2, 65.5, and 66.6 years in groups 1, 2, and 3, respectively. The median for fused levels was 4 for the three groups. There was no significant difference between groups regarding the number of fused levels. Weight, height, comorbidities, and diagnosis were not significantly different between groups. Preoperative JOA scores were similar between groups (p = 0.256), whereas the preoperative NDI score was significantly higher in group 3 than in group 2 (p = 0.040). Mean JOA score at 12-month follow-up was 15.5 ± 1.89, 16.1 ± 1.48, and 16.1 ± 1.48 for groups 1, 2, and 3, respectively; it was higher in group 3 compared with group 1 (p = 0.008) and in group 2 compared with group 1 (p = 0.024). NDI score at 12 months was 13, 12, and 13 in groups 1, 2, and 3, respectively; it was significantly better in group 3 than in group 1 (p = 0.040), but there were no other significant differences between groups. The incidence of C5 palsy was significantly lower in posterior foraminotomy groups with pedicle screws (groups 2 and 3) than in LMS with uncovertebrectomy (group 1) (p < 0.001). Thus, preventive expansive foraminotomy before decompressive laminectomy is able to significantly decrease the root tethering by stenotic lesion, and subsequently, decrease the incidence of C5 palsy associated with posterior only or combined posterior and anterior cervical fusion surgeries. Additionally, such expansive foraminotomy might be appropriate with pedicle screw insertion based on biomechanical considerations.

Cervical kinematic change after posterior full-endoscopic cervical foraminotomy for disc herniation or foraminal stenosis

OBJECTIVE

Posterior full-endoscopic cervical foraminotomy (PECF) is one of minimally invasive surgical techniques for cervical radiculopathy. Because of minimal disruption of posterior cervical structures, such as facet joint, cervical kinematics was minimally changed. However, a larger resection of facet joint is required for cervical foraminal stenosis (FS) than disc herniation (DH). The objective was to compare the cervical kinematics between patients with FS and DH after PECF.

METHODS

Consecutive 52 patients (DH, 34 vs. FS, 18) who underwent PECF for single-level radiculopathy were retrospectively reviewed. Clinical parameters (neck disability index, neck pain and arm pain), and segmental, cervical and global radiological parameters were compared at postoperative 3, 6, and 12 months, and yearly thereafter. A linear mixed-effect model was used to assess interactions between groups and time. Any occurrence of significant pain during follow-up was recorded during a mean follow-up period of 45.5 months (range 24-113 months).

RESULTS

Clinical parameters improved after PECF, with no significant differences between groups. Recurrent pain occurred in 6 patients and surgery (PECF, anterior discectomy and fusion) was performed in 2 patients. Pain-free survival rate was 91% for DH and 83% for FS, with no significant difference between the groups (P = 0.29). Radiological changes were not different between groups (P > 0.05). Segmental neutral and extension curvature became more lordotic. Cervical curvature became more lordotic on neutral and extension X-rays, and the range of cervical motion increased. The mismatch between T1-slope and cervical curvature decreased. Disc height did not change, but the index level showed degeneration at postoperative 2 years.

CONCLUSION

Clinical and radiological outcomes after PECF were not different between DH and FS patients and kinematics were significantly improved. These findings may be informative in a shared decision-making process.

A Novel Method of Making Hinges Using a Newly Designed Sharp Rongeur to Enhance Radiological and Clinical Outcomes in French-Door Cervical Expansive Laminoplasty

OBJECTIVE

Although the lamina open angle of making hinges is closely related to the outcomes of French-door laminoplasty (FDL) for treatment of cervical spondylosis, there have been no methods to predict the lamina open angle preoperatively as yet. The aim of this study was to investigate the accuracy of predicting the laminal open angle using our newly designed sharp rongeur, and to compare the postoperative outcomes and complications between the methods of making hinges using the newly designed sharp rongeur and the traditional high-speed micro-drill during the FDL.

METHODS

This was a single-center retrospective study. Following the approval of the institutional ethics committee, a total of 39 patients (Male: 28; Female: 11) diagnosed with cervical spondylos who underwent FDL in our institution between January 2018 and May 2019 were enrolled. Patients were divided into two groups based on the method of making hinges (sharp rongeur: 22 cases; high-speed micro-drill: 17 cases). The average age at surgery was 59.1 years (range: 16-85 years). The radiological parameters, clinical outcomes, modified Japanese Orthopaedic Association (mJOA) scale score, and the recovery rate of mJOA were recorded and compared between the groups, respectively. The radiological parameters and clinical measurements at pre- and post-operation stages were compared using the paired-sample t-test, the Wilcoxon signed-rank test, and the Friedman's test, and variables in the two groups were analyzed using an unpaired Student's t-test or a Mann-Whitney U test.

RESULTS

The average follow-up period was 20.4 months (range: 14.0-25.9 months), the postoperative open angle was 60.13° ± 3.69° in the rongeur group with 22.78° ± 4.34° of angular enlargement, which was significantly lower than that of 68.96° ± 1.00° in the micro-drill group with 32.75° ± 4.22° of angular enlargement (U = 19.000, p < 0.001). The rongeur group showed a higher fusion rate (34.1% vs 14.7%, χ²  = 11.340, p = 0.001), and a lower fracture rate of the lamina (7.8% vs 25.5%, χ²  = 14.185, p < 0.001) at 1-month post-surgery, compared to the micro-drill group. There were no significant differences in the clinical outcomes and postoperative complications between the two groups (p > 0.05), except in the recovery rate of mJOA scores (0.836 ± 0.138 vs 0.724 ± 0.180, U = 115.000, p = 0.042) and neck disability index (NDI) at the final follow-up (7.55 ± 10.65 vs 14.71 ± 8.72, U = 94.000, p = 0.008).

CONCLUSIONS

The special sharp rongeur with a tip angle of 20° could be a preferred method to make hinges during FDL, which can predict the laminal open angle accurately and enlarge it to about 23°, thus reducing the fracture rate and accelerating the bony fusion of hinges compared with the outcomes of the traditional micro-drill method.

[Research progress of etiologies for C 5 palsy after cervical decompression]

Objective

To review the definition and possible etiologies for C ₅ palsy.

Methods

The literature on C ₅ palsy at home and abroad in recent years was extensively reviewed, and the possible etiologies were analyzed based on clinical practice experience.

Results

There are two main theories (nerve root tether and spinal cord injury) accounting for the occurrence of C ₅ palsy, but both have certain limitations. The former can not explain the occurrence of C ₅ palsy after anterior cervical spine surgery, and the latter can not explain that the clinical symptoms of C ₅ palsy is often the motor dysfunction of the upper limb muscles. Based on the previous reports, combining our clinical experience and research, we propose that the occurrence of C ₅ palsy is mainly due to the instrumental injury of anterior horn of cervical spinal cord during anterior cervical decompression. In addition, the C ₅ palsy following surgery via posterior approach may be related to the nerve root tether caused by the spinal cord drift after decompression.

Conclusion

In view of the main cause of C ₅ palsy after cervical decompression, it is recommended to reduce the compression of the spinal cord by surgical instruments to reduce the risk of this complication.

C5 palsy after cervical laminectomy: natural history in a 10-year series

BACKGROUND CONTEXT

C5 palsy is a well-known complication following cervical laminectomy, however the cause of this complication remains elusive, with many studies providing conflicting reports on prognosis and the impact of specific risk factors.

PURPOSE

To describe the natural history of and risk factors for C5 palsy after first time cervical laminectomy involving C4 and/or C5, in a large series with a high rate of postoperative palsy.

STUDY DESIGN/SETTING

This is a retrospective case series.

PATIENT SAMPLE

Patients undergoing first time cervical laminectomy for degenerative spine pathologies at a single institution between January 2008 and July 2018. Adult patients were included if a complete laminectomy was performed at C4 or C5 for degenerative pathology and pre- and postoperative upright lateral x-rays were performed.

OUTCOME MEASURES

The primary outcome measure was postoperative C5 palsy, defined as a decrease in strength of at least one point in deltoid and/or biceps within 30 days of operation. The secondary outcome measure was recovery of function.

METHODS

A retrospective database of patients who underwent posterior cervical spine surgery was created and further focused by utilizing specific Common Procedural Technology (CPT) codes associated with our desired patient population. Patients were excluded from our study if they had inadequate pre- and postoperative imaging, as well as patients with a history of prior cervical spine surgery, concurrent anterior surgery, intradural pathology, spinal tumor, or spinal trauma. Patient history, surgical specifics, and neurologic function were recorded.

RESULTS

A total of 190 patients were treated by 13 surgeons. 53 (27.9%) developed C5 palsy postoperatively. Of patients with C5 palsy, 40 (75.5%) recovered to baseline strength, 46 (86.6%) had at least grade 4 strength at last follow up, and 4 (7.5%) had strength worse than baseline and motor grade less than 4. Median time to recovery was 2.0 (IQR: 0.18 to 8.24) months. Age, gender, preoperative motor score, number of levels decompressed, smoking history, and comorbidities were not associated with a significant increase in the odds of C5 palsy. Risk of C5 palsy increased by 35% for every additional level fused below C4.

CONCLUSION

The risk of C5 palsy is increased with instrumentation caudal to C5 in operations addressing degenerative cervical pathology. This should be taken into consideration during operative planning. Overall prognosis of C5 palsy is good; however, incidence of this condition may be greater than previously reported.

Preoperative Radiological Parameters to Predict Clinical and Radiological Outcomes after Laminoplasty

Many studies have focused on pre-operative sagittal alignment parameters which could predict poor clinical or radiological outcomes after laminoplasty. However, the influx of too many new factors causes confusion. This study reviewed sagittal alignment parameters, predictive of clinical or radiological outcomes, in the literature. Preoperative kyphotic alignment was initially proposed as a predictor of clinical outcomes. The clinical significance of the K-line and K-line variants also has been studied. Sagittal vertical axis, T1 slope (T1s), T1s-cervical lordosis (CL), anterolisthesis, local kyphosis, the longitudinal distance index, and range of motion were proposed to have relationships with clinical outcomes. The relationship between loss of cervical lordosis (LCL) and T1s has been widely studied, but controversy remains. Extension function, the ratio of CL to T1s (CL/T1s), and Sharma classification were recently proposed as LCL predictors. In predicting postoperative kyphosis, T1s cannot predict postoperative kyphosis, but a low CL/T1s ratio was associated with postoperative kyphosis.

Use of electromyography to predict likelihood of recovery following C5 palsy after posterior cervical spine surgery

BACKGROUND

C5 palsy affects approximately 5% to 10% of patients undergoing cervical spine surgery. It has a significant negative impact on patient quality-of-life outcomes and healthcare costs. Although >80% of patients improve, some are left with persistent, debilitating deficits. Our objective was to examine if electrodiagnostic testing could be used to successfully identify patients likely to experience complete, partial, and no recovery.

METHODS

Patients undergoing posterior cervical decompression and fusion at a single institution over a 10-year period were identified. Those experiencing postoperative C5 palsy were included. Outcomes examined included motor recovery of the affected deltoid as a function of time, and changes in electrodiagnostic testing as a function of time since injury. Electrodiagnostic testing included electromyography and was sub-analyzed by time of acquisition postinjury. Deltoid strength was graded on manual motor testing using the 5-point medical research council grading system.

RESULTS

Of 77 patients experiencing C5 palsy, 29 had postoperative electrodiagnostic testing. Patients experiencing complete recovery on average achieved functional (4/5) strength by 6-weeks post injury and 4+ per 5 strength by 6-months. Those experiencing partial recovery only achieved antigravity strength (3/5) by 6-weeks and low-function (4-/5) strength by 6-months. Electrodiagnostic testing performed 6-weeks to 6-months postinjury demonstrated that those experiencing complete recovery were more likely to have normal motor unit (MU) recruitment than those experiencing partial (p<.001) or no recovery (p=.008). The presence of ≥2+ fibrillation on tests acquired ≤6-weeks of injury identified patients unlikely to experience any recovery with a positive predictive value (PPV) of 88.9%. The presence of normal MU recruitment on tests acquired 6-weeks to 6-months postinjury identified patients likely to experience complete recovery with a PPV of 87.5%.

CONCLUSIONS

Electrodiagnostic testing may be a valuable means of differentiating between patients with C5 palsy likely to experience complete, partial, or no recovery. Testing between 6-weeks and 6-months post onset may aid in identifying those least likely to have a complete recovery. No MUs at 4 to 6-months, or reduced units with strength that is not improving, portends a poor long-term outcome. In this population, peripheral nerve transfers may be considered sooner.

A new nomenclature system for the surgical treatment of cervical spine deformity, developing, and validation of SOF system

PURPOSE

To develop and assess the reliability of new nomenclature system that systematically organizes osteotomy techniques and briefly describes the surgical approach, the surgical sequence, and the fixation technique for cervical spine deformity (CSD).

METHODS

We developed a new classification system (SOF system) for CSD surgery that describes the sequence of surgical approach (S), the grade of osteotomy (O), and the information of fixation (F) using alphanumeric codes. Twenty CSD osteotomies (8 anterior osteotomies, 12 posterior osteotomies) were included in this study to evaluate the inter- and intra-observer agreement based on operation records. Six observers performed independent evaluations of the operation records in random order. Each observer described 20 CSD surgeries using the SOF system twice (> 30 days between assessments) based on operation records to validate SOF system.

RESULTS

Overall agreement (among all six observers at the initial assessment) on the anterior and posterior osteotomy was ICC = 0.96 and ICC = 0.91, respectively. Overall agreement (repeat observations after at least 30 days) on the anterior and posterior osteotomy was ICC = 0.96 and ICC = 0.91, respectively. This data showed that both inter- and intra-observer agreement revealed 'excellent'.

CONCLUSION

This study introduces the SOF system of the CSD surgery to understand the surgical sequence, the type of osteotomy and the fixation techniques. The investigation of the inter- and intra-observer agreement revealed 'excellent agreement' for both anterior and posterior osteotomies. Thus, SOF system can provide a consistent description of the various CSD surgeries and its use will provide a common frame for CSD surgery and help communicate between surgeons.

Phrenic nerve palsy after cervical laminectomy and fusion

Background

Outcome

Conclusions

A modified cutting line in the single-door cervical laminoplasty via a computed tomography-based morphological study of the subaxial cervical spine

OBJECTIVE

To modify the conventional methods of grooving and direction during the single-door cervical laminoplasty (SDCL) in the subaxial cervical spine.

METHODS

The distance between the left and the right lamina-lateral mass junction at the upper, middle, and lower levels of each segment (DLL-U, DLL-M, DLL-L), angle between the posterior edge of the vertebral body and the lamina (AVL) and thickness of lamina (TL) were measured in the transverse plane. The parameters of preoperative computed tomography scans of 200 patients who had undergone SDCL were measured. The patients were divided into male and female groups and developmental canal stenosis (DCS) and non-DCS (NDCS) groups.

RESULTS

DLL-M gradually increased from the cranial to the caudal except for C7, and DLL-L > DLL-M > DLL-U in each vertebra. AVL increased from C3 to C7, TL decreased from C3 to C5 and increased from C5 to C7, with both parameters showing no significant differences between the left and right sides. AVL of the DCS group was less than that of the NDCS group (P < 0.01).

CONCLUSIONS

In the SDCL, the ideal surgical trough should be several discontinuous lines sloping from top to bottom, rather than a straight line. The abduction angle during drilling should gradually increase from C3 to C7 in the SDCL averaging 40 degrees. This method mentioned above improves the efficiency of the operation with less blood loss as an extended cut into the lateral mass is avoided.