Incidence of C5 palsy in anterior cervical decompression & fusion, posterior cervical decompression & fusion and laminoplasty for degenerative cervical myelopathy: systematic review and meta-analysis of 21,231 cases.

A prospective comparative study about the incidence of postoperative C5 palsy and multivariate analysis of the risk factors of C5 palsy. To clarify the risk factors of occurrence of C5 palsy after laminoplasty (LP) by comparing the 2 surgical procedures of open-door and double-door LP prospectively. The incidence of C5 palsy has been reported to average 4.6%, and there has been no difference of the incidence among surgical procedures. However, there were only indirect retrospective studies. A total of 146 patients who underwent the LP procedure between 2006 and 2007 were studied prospectively. In 2006, the patients were assigned to undergo the open-door LP, and in 2007, they were assigned to undergo the double-door LP. The incidence of postoperative C5 palsy was compared prospectively between these 2 LP procedures, and the risk factors of C5 palsy were detected with multivariate logistic regression analysis. Postoperative C5 palsy occurred in 7 of 73 cases after open-door LP (9.6%) and in 1 of 73 cases after double-door LP (1.4%). The incidence of C5 palsy after open-door LP was statistically higher than the one after double-door LP (P = 0.029), and open-door LP was recognized as a significant risk factor for postoperative C5 paralysis (odds ratio: 69.6, P = 0.043). In addition, ossification of posterior longitudinal ligament (OPLL) was recognized as a significant risk factor for postoperative C5 paralysis (odds ratio: 43.8, P = 0.048). This study showed significant evidence indicating the higher risk of postoperative C5 palsy in open-door LP than double-door LP. Because OPLL as well as open-door LP were recognized as the risk factors of C5 palsy, asymmetric decompression by open-door LP might introduce imbalanced rotational movement of spinal cord and result in C5 palsy. We recommend double-door LP to minimize the postoperative C5 palsy, in particularly, if the patient has OPLL.

Despite the favorable postoperative prognosis of C5 palsy (C5P), a certain proportion of these patients have less satisfactory outcomes. The current systematic review and meta-analysis thus aimed to comprehensively evaluate existing literature and identify the onset, recovery patterns, and outcomes of C5P following diverse surgical approaches. Five different databases (Google Scholar, Embase, PubMed, Web of Science, and Cochrane Library) were thoroughly searched for relevant literature on October 15, 2024. Studies reporting on incidences of C5P following surgery for degenerative cervical conditions with recovery data published until 2024 were scrutinized. Narrative or systematic reviews, opinions, letters to the editor, and manuscripts published in non-English languages were excluded. A total of 30 articles involving 8,116 patients who underwent undergoing surgery for degenerative cervical myelopathy with 748 reported C5P cases were included for analysis. The overall time to palsy reported in the included studies was 3 days (95% confidence interval [CI], 2.56-3.60). Palsy occurred earliest with anterior cervical decompression and fusion (ACDF) at 2 days (95% CI, 0.35-4.54), followed by laminoplasty (LP) at 3.2 days (95% CI, 2.02-4.34) and posterior cervical decompression and fusion (PCDF) at 3.6 days (95% CI, 2.81-4.37). Patients with palsy showed improved recovery with time. At the 1-year follow-up, the reported recovery rates were 100%, 52.9%, and 50% for ACDF, LP, and PCDF, respectively. C5P demonstrated a delayed presentation, with mean onset of 3 days after surgery, which can range from 2 days for ACDF to 3.6 days for PDCF. Recovery improved progressively with time and varied for different surgical procedures, with ACDF showing the best recovery and PDCF for cervical myelopathy showing the poorest recovery.

Introduction C5 palsy following cervical decompression is a known complication. The exact incidence is unclear, due to varying definitions in literature. C5 palsy is associated with significant morbidity due to weakness of deltoid/biceps. Aim To report incidence of postoperative C5 palsy in cervical decompression surgeries for myelopathy and its correlation with demographic factors, etiology, radiological factors, and to assess recovery of palsy. Materials and Methods All patients who underwent cervical decompression surgeries from 2006 to 2015 in a single institute were reviewed. A postoperative decrease by ≥ 1 manual muscle testing grade in only C5 myotome (deltoid/biceps/both) is taken as positive. Demographic, radiological, surgical factors resulting in C5 palsy and time of onset, duration of symptoms, and degree of recovery were noted. Results A total of 390 patients were included in the study. Out of which, 232 patients underwent anterior while 158 had posterior surgeries. In all, 72 patients had ossification of the posterior longitudinal ligament (OPLL) and rest had spondylotic myelopathy. Incidence of palsy was 6.3% and mean onset of palsy was 2.8 days. Mean duration for recovery was 6.3 months with near complete recovery seen in majority of the patients (9/10). No significant relation was noted with age, preoperative Japanese Orthopedic Association score, change in cervical lordosis, and C45 intervertebral angle. Posterior surgeries, laminectomy, C45 foraminal stenosis, and OPLL were seen as risk factors for C5 palsy. Conclusion Cervical decompression surgeries are relatively safe, with a small risk of C5 palsy. Though majority of patients recover with conservative treatment, preoperative counseling of this complication has to be explained.

Postoperative C5 palsy is a common complication after cervical spine decompression surgery. However, the incidence, prognosis, and etiology of C5 palsy after anterior decompression with spinal fusion (ASF) have not yet been fully established. In the present study, we analyzed the clinical and radiological characteristics of patients who developed C5 palsy after ASF for cervical degenerative diseases. The cases of 199 consecutive patients who underwent ASF were analyzed to clarify the incidence of postoperative C5 palsy. We also evaluated the onset and prognosis of C5 palsy. The presence of high signal changes (HSCs) in the spinal cord was analyzed using T2-weighted magnetic resonance images. C5 palsy occurred in 17 patients (8.5%), and in 15 of them, the palsy developed after ASF of 3 or more levels. Among ten patients who had a manual muscle test (MMT) grade ≤2 at the onset, five patients showed incomplete or no recovery. Sixteen of the 17 C5 palsy patients presented neck and shoulder pain prior to the onset of muscle weakness. In the ten patients with a MMT grade ≤2 at the onset, nine patients showed HSCs at the C3-C4 and C4-C5 levels. The present findings demonstrate that, in most patients with severe C5 palsy after ASF, pre-existing asymptomatic damage of the anterior horn cells at C3-C4 and C4-C5 levels may participate in the development of motor weakness in combination with the nerve root lesions that occur subsequent to ASF. Thus, when patients with spinal cord lesions at C3-C4 and C4-C5 levels undergo multilevel ASF, we should be alert to the possible occurrence of postoperative C5 palsy.

A systematic review and meta-analysis were performed with the literature including the case of C5 palsy following anterior cervical decompression surgery. The aim of this study was to compare three reconstructive procedures of anterior cervical decompression, the incidences of delayed C5 palsy and other complications were assessed. Delayed C5 palsy is now a well-known complication after cervical decompression surgery. The etiology of C5 palsy has been studied, especially after posterior surgery. However, in anterior surgery there has been a lack of investigation due to procedure variation. Additionally, limited evidence exists regarding the risk of C5 palsy in surgical procedures. We performed an extensive literature search for C5 palsy and other complications with ACDF, ACCF, and their combination (Hybrid). Gross incidences of C5 palsy after these three procedures were compared, and specific superiorities (or inferiorities) were investigated via comparison of binary outcomes between two of three groups using odds ratios (OR). Twenty-six studies met the inclusion criteria. A total of 3098 patients were included and 5.8% of those developed C5 palsy. Meta-analyses demonstrated that ACDF had a lower risk of palsy than ACCF (OR 0.36, 95% confidence interval [CI] 0.16-0.78), whereas ACDF versus Hybrid (OR 0.60, 95% CI 0.24-1.51) and Hybrid versus ACCF (OR 1.11, 95% CI 0.29-4.32) were not significantly different. Although these differences were not observed in shorter lesion subgroups, there were significant differences between the three procedures in longer lesion subgroups (P = 0.0005). Meta-analyses revealed that in longer lesions, ACDF had a significantly lower incidence than ACCF (OR 0.42, 95% CI 0.22-0.82). Additionally, Hybrid surgery was noninferior for palsy occurrence compared to ACCF, and suggested a trend for reduced rates of other complications compared to ACCF. ACDF may yield better outcomes than Hybrid and ACCF. Furthermore, Hybrid may have advantages over ACCF in terms of surgical complications. 3.

Dear Editor, With interest I read the article by Hashimoto et al. [1] describing C5 palsy following anterior decompression and spinal fusion for cervical degenerative diseases. C5 palsy is still a controversial entity for which we do not have a clear understanding of the pathophysiology. There are several potential hypotheses, which have been discussed for more than a decade. The two most-commonly proposed explanations are tethering of nerve roots and localized reperfusion spinal cord injury. Many articles, which have described C5 palsy are from Japan leading some spine surgeons in other countries to regard C5 palsy as a complication of laminoplasty. Please allow me to communicate my unique viewpoint regarding C5 palsy. I have been trained in spinal surgery both in Japan and the US and noticed several important differences in the treatment of cervical spine disease. Anterior cervical decompression and fusion (ACDF) is much more popular than laminoplasty in the US and ACDF cases for treatment of cervical radiculopathy is much more common in the US. One principle difference in postoperative care between Japan and the US is the length of the hospital stay. In the US, patients are usually discharged 1 or 2 days after surgery compared with around 7 days in Japan. After postoperative day 1 or 2, muscle strength is not usually tested by surgeons in the US. On the other hand, patients have motor strength testing by their surgeons every day for 1 week in Japan. C5 palsy often occurs 2–7 days after surgery. Shoulder elevation may not be important to patients during short-term recovery period after ACDF and so patients in the US may never notice weakness of the deltoid muscle. The C5 palsy often recovers quickly enough that strength can also recover without notice. I believe early hospital discharge contributes to the rare reports of C5 palsy in the US. I feel laminoplasty is not favored in the US partially due to the perceived increased risk of C5 palsy. But, as Hashimoto et al. [1] mentioned, the incidence of C5 palsy after ACDF was 4.3% on average and ranged from 1.6 to 12.1%, similar to the incidence after laminoplasty although the number of reports describing anterior surgery was smaller than for posterior surgery. If tethering of nerve roots is the cause of C5 palsy, this cannot explain C5 palsy after ACDF because the spinal cord does not shift posteriorly after surgery. Imagama et al. [2] recently studied the clinical features and radiological findings of C5 palsy in patients after cervical laminoplasty and reported that a group of patients who developed C5 palsy had significant narrowing of the intervertebral foramen of C5 after laminoplasty. But ACDF surgery usually opens up the foramen via indirect decompression, which also does not explain why patients have a similar rate of C5 palsy after ACDF. Chiba et al. [3] studied C5 palsy patients after expansive open-door laminoplasty using magnetic resonance imaging (MRI) and suggested that a certain impairment in the gray matter of the spinal cord may play an important role in C5 palsy. Hasegawa et al. [4] studied C5 palsy patients with chronic cervical cord compressive lesions who underwent decompression surgery and compared the incidence of C5 palsy among anterior and posterior procedures. They found no differences among procedures and concluded that C5 palsy might result from a transient and localized spinal cord lesion caused by reperfusion after decompression of a chronic compressive lesion. Hashimoto et al. [1] did not find C5 palsy in the two patients with disc herniation or in the six patients with cervical spondylotic radiculopathy. If spinal cord compression and poor spinal cord perfusion is a major factor in causing C5 palsy, the incidence of C5 palsy after ACDF for radiculopathy would be expected to be very low. As a high proportion of ACDF cases in the US are done for radiculopathy, C5 palsy would not be common in general. Most of the articles describing C5 palsy include mostly patients with cervical myelopathy and fewer patients with radiculopathy as seen in the Hashimoto et al. article [1]. Future studies of large cohorts to compare the incidence of C5 palsy after ACDF between patients with radiculopathy and those with myelopathy will be important in learning about the pathophysiology of C5 palsy.

A prospective study. To evaluate the effectiveness of prophylactic C4/C5 microforaminotomy with open-door laminoplasty for cervical myelopathy in preventing postoperative C5 palsy. Postoperative C5 palsy is a common complication of cervical laminoplasty. Although the etiology of C5 palsy and preventive measures remain unclear, we hypothesize that C5 palsy is caused by C5 nerve root impairment induced by potential C4/C5 foraminal stenosis and posterior shifting of the spinal cord after laminoplasty. The study included 141 consecutive patients with cervical myelopathy (103 men and 38 women) who underwent open-door laminoplasty with prophylactic bilateral C4/C5 foraminotomy between 2009 and 2010. These were designated as the foraminotomy group (FG). One hundred forty-one consecutive patients (100 men and 41 women) who underwent open-door laminoplasty without prophylactic foraminotomy during 2006 to 2008 served as a control group. This was the nonforaminotomy group (NFG). The incidence of C5 palsy, operation time, blood loss, and the number of decompressed disc levels were recorded. The incidence of C5 palsy was 1.4% (2 of 141 cases) in the FG, and 6.4% (9 of 141 cases) in the NFG. The mean operation times were 129 and 102 minutes, respectively. There were significant differences in the incidence of C5 palsy and operation time (both comparisons, P < 0.05). There were no significant differences in blood loss or the number of decompressed disc levels (both comparisons, P > 0.05). Prophylactic bilateral C4/C5 microforaminotomy significantly decreased the incidence of postoperative C5 palsy. These results suggest that the main etiology of C5 palsy was C5 root impairment. However, 2 patients experienced C5 palsy despite undergoing prophylactic foraminotomy, which indicated that other factors including spinal cord impairment after acute decompression against cervical canal stenosis may also be considered as minor etiologies of C5 palsy. We conclude that prophylactic C4/C5 foraminotomy was an effective preventive measure against postoperative C5 palsy after laminoplasty.

Retrospective study. To determine the risk factors for insufficient recovery from C5 palsy (C5P) following anterior cervical decompression and fusion (ADF). Postoperative C5P is a frequent but unsolved complication following cervical decompression surgery. Although most patients gradually recover, some recover only partially. When we encounter new-onset C5P following ADF, the question that often arises is whether the palsy will sufficiently resolve. We retrospectively reviewed consecutive patients who underwent ADF at our institution. We defined C5P as postoperative deterioration of deltoid muscle strength by two or more grades determined by manual muscle testing (MMT). We evaluated the following demographic data: patient factors, surgical factors, and radiological findings. C5P patients were divided into two groups: sufficient recovery (MMT grade≧4) and insufficient recovery (MMT grade < 4). Each parameter was compared between the two groups. Of 839 patients initially included in the study, 57 experienced new-onset C5P (6.8%). At the final follow-up (mean, 55 ± 17 months), 41 patients experienced sufficient recovery, whereas 16 (28%) still exhibited insufficient recovery. Compared with the sufficient recovery group, patients with insufficient recovery exhibited a higher decompression combination score, a larger anterior shift in preoperative cervical sagittal balance, less lordosis of the pre- and postoperative C4/C5 segment, more frequent stenosis at the C3/C4 segment, lower deltoid strength at C5P onset, more frequent co-occurrence of biceps weakness, greater postoperative expansion of the dura mater, and more frequent presence of postoperative T2 high-intensity areas. Multivariate analysis revealed that co-occurrence of biceps muscle weakness, less lordosis at the preoperative C4/C5 segment, and postoperative expansion of the dura mater were independent predictors of insufficient recovery. The combination of unfavorable conditions, such as potential spinal cord disorder, cervical malalignment, and excessive expansion of the dura mater after corpectomy, predicts insufficient recovery from C5P.Level of Evidence: 4.

Friday, September 28, 2018 4:05 PM–5:05 PM abstracts: new concepts: cervical spine: 246. C5 palsy after single- and multilevel anterior cervical discectomy and fusion

Study Design Review of literature. Objectives To review the literature regarding the clinical features, incidence, underlying mechanism, possible prevention, and prognosis of C5 palsy after cervical decompression surgery. Summary of Background Data Palsy of the C5 nerve after cervical spine decompression surgery is a well-known complication. There is persistent controversy concerning the underlying mechanism and appropriate prophylaxis. Methods A review of studies describing C5 palsy after cervical spine decompression procedures was carried out. Results Postoperative C5 palsy can be present after cervical spine decompression with a reported incidence between 0% and 50%. Postoperative C5 palsy has been reported regardless of the underlying cause of cervical spinal cord compression and the surgical procedure carried out. The current literature describes 5 basic underlying mechanisms. These include direct injury to the nerve root, segmental spinal cord pathology, progressive cervical spine malalignment and instability, nerve root traction, and abnormal spinal cord blood flow and reperfusion injury. The true pathomechanism of postoperative C5 palsy remains unclear and no single method of prevention is regularly used. The prognosis of postoperative C5 palsy is generally good with full recovery reported in the majority of patients. Conclusions Postoperative C5 palsy is a complication seen after surgical decompression of the cervical spine. It can occur regardless of the cause of cervical spinal cord compression and the surgical procedure carried out. Numerous theories exist as to the underlying cause of postoperative C5 palsy, but there is no strong evidence to support any single pathomechanism or appropriate prophylaxis. Most patients with postoperative C5 palsy experience full recovery within 6 months, although many patients continue to have some residual pain or neurologic deficit.

A literature review was conducted to integrate and compile available reports on postoperative C5 palsy. To review the clinical features, possible pathogenesis, and procedures for treatment and prevention of postoperative C5 palsy as a complication of surgery for cervical compression myelopathy. Although postoperative C5 palsy develops in approximately 5% of patients after decompression surgery of the cervical spine, its pathogenesis and the options for prevention and treatment remain unidentified and many controversies exist. We reviewed and analyzed papers published from 1986 to 2002 regarding C5 palsy as a postoperative complication. Statistical comparisons were made when appropriate. Postoperative C5 palsy is reported to occur in an average of 4.6% of patients after surgery for cervical compression myelopathy. No significant differences were noted between patients undergoing anterior decompression and fusion and laminoplasty, nor were distinctions apparent between unilateral hinge laminoplasty and French-door laminoplasty, or between cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament. Two theories were put forth to account for the pathogenesis of C5 palsy: nerve root injury and segmental spinal cord disorder. Neither of these hypotheses has been consistently supported and evidence to refute each hypothesis can be found in the literature. Recently, surgeons have advocated foraminotomy combined with laminoplasty to prevent or treat C5 palsy, but further studies into the efficacy of this procedure are needed. Although patients with C5 palsy generally have a good prognosis for neurologic and functional recovery, those with severe paralysis require significantly longer recovery times when compared to more mild cases. The incidence of postoperative C5 palsy has been reported at 4.6% after surgery for cervical compression myelopathy and this value has not varied with different surgical procedures or disease etiologies. The pathogenesis of postoperative C5 palsy remains unclear at the present time. Patients with postoperative C5 palsy generally have a good prognosis for functional recovery, but the severely paralyzed cases required significantly longer recovery times than the mild cases.

Retrospective cohort study of prospectively accrued data. To evaluate a large, prospective, multicentre dataset of surgically treated degenerative cervical myelopathy (DCM) cases on the contemporary risk of C5 palsy with surgical approach. The influence of surgical technique on postoperative C5 palsy after decompression for DCM is intensely debated. Comprehensive, covariate-adjusted analyses are needed using contemporary data. Patients with moderate to severe DCM were prospectively enrolled in the multicenter, randomized, Phase III CSM-Protect clinical trial and underwent either anterior or posterior decompression between Jan 31, 2012 and May 16, 2017. The primary outcome was the incidence of postoperative C5 palsy, defined as the onset of muscle weakness by at least one grade in manual muscle test at the C5 myotome with slight or absent sensory disruption after cervical surgery. Two comparative cohorts were made based on the anterior or posterior surgical approach. Multivariate hierarchical mixed-effects logistic regression was used to estimate odds ratios (OR) with 95% confidence intervals (CI) for C5 palsy. A total of 283 patients were included, and 53.4% underwent posterior decompression. The total incidence of postoperative C5 palsy was 7.4% and was significantly higher in patients who underwent posterior decompression compared with anterior decompression (11.26% vs. 3.03%, P =0.008). After multivariable regression, the posterior approach was independently associated with greater than four times the likelihood of postoperative C5 palsy ( P =0.017). Rates of C5 palsy recovery were comparable between the two surgical approaches. The odds of postoperative C5 palsy are significantly higher after posterior decompression compared to anterior decompression for DCM. This may influence surgical decision-making when there is equipoise in deciding between anterior and posterior treatment options for DCM. Therapeutic Level-II.

Single-center retrospective study. We examined whether extremely wide and asymmetric anterior decompression causes postoperative C5 palsy. Postoperative C5 palsy is a complication of cervical decompression surgery. We hypothesized that C5 palsy may be caused by nerve root impairment through extremely wide and asymmetric dural expansion due to unilateral predominant wide anterior decompression with concomitant C4-C5 foraminal stenosis. The study included 32 patients with postoperative C5 palsy from a cohort of 459 patients who underwent anterior cervical decompression and fusion at the C4-C5 disc level for cervical myelopathy. The 64 upper extremities were divided into 2 groups according to palsy side (n = 35) or nonpalsy side (n = 29). Also, to correlate radiological findings, 66 consecutive patients who underwent anterior cervical decompression and fusion without postoperative C5 palsy were selected as control. In patients with C5 palsy, the unilateral decompression width on the palsy side was significantly larger than that on the nonpalsy side (8.63 vs. 6.92 mm, P = 0.0003). In addition, the decompression width was significantly larger (15.69 vs. 14.38 mm, P = 0.02), the diameter of the C4-C5 foramen was significantly smaller (2.73 vs. 3.24 mm, P = 0.0008), the anterior spinal cord shift was significantly smaller (0.14 vs. 0.73 mm, P< 0.0001), and significant decompression asymmetry (0.74 vs. 0.89, P = 0.0003) was present in the patients with C5 palsy compared with controls. Extremely wide and asymmetric decompression concomitant with pre-existing C4-C5 foraminal stenosis may cause postoperative C5 palsy. Our findings should be valuable for surgeons considering anterior cervical decompression and fusion that includes the C4-C5 level. Surgeons should consider restriction of the decompression width to less than 15 mm and avoiding asymmetric decompression to reduce the incidence of C5 palsy.

The incidence of C5 palsy after cervical laminoplasty is approximately 5%. Because C5 palsy is related to cervical foraminal stenosis at the C4-5 level, the authors hypothesized that cervical foraminal stenosis can be diagnosed by examining the C5 nerve root (NR) using ultrasonography. The purpose of this study was to investigate whether postoperative C5 palsy could be predicted using ultrasonography. This study used a prospective diagnosis design. In total, 140 patients undergoing cervical laminoplasty were examined with ultrasound. The cross-sectional area (CSA) of the C5 NR was measured on both sides before surgery, and the incidence of postoperative C5 palsy was examined. The difference between the CSA of the patients with and without C5 palsy and the lateral differences in the C5 palsy group were determined. The incidence of C5 palsy was 5% (7 cases). Symptoms manifested at a median of 5 days after surgery (range 1-29 days). The CSA of the C5 NR on the affected side was significantly enlarged in the C5 palsy group compared with that in the no-C5 palsy group (p = 0.001). In addition, in the patients who had C5 palsy, the CSA of the C5 NR was significantly enlarged on the affected side compared with that on the unaffected side (p = 0.02). Receiver operating characteristic analysis indicated that the best threshold value for the CSA of the C5 NR was 10.4 mm2, which provided 91% sensitivity and 71% specificity. C5 palsy may be predicted preoperatively using ultrasound. The authors recommend the ultrasonographic measurement of the CSA of the C5 NR prior to cervical laminoplasty.

C5 palsy is a well-known complication of cervical spine decompression surgery. The complication develops in both posterior and anterior approaches. We aimed to review reports regarding postoperative C5 palsy in hopes for better prevention and treatment of this morbidity. We systematically reviewed and evaluated the abstracts and full texts of the identified papers in the literature. We reviewed and analyzed papers published between January 1970 and February 2015 regarding C5 palsy as a complication of cervical surgical procedures. We made statistical comparisons as much as possible. We did not find any statistical significance between the pathologies (p=0.088) and between the surgical routes (p=0.486). There was statistical significance between the types of procedures (p<0.05). Posterior laminectomy had low incidence of C5 palsy when compared to laminectomy and fusion (p=0.029) and laminoplasty (p=0.37). There was no statistically significant difference between anterior cervical decompression and fusion and other procedures (p>0.05). Some studies conclude that anterior procedure is more safe. Of all anterior procedures, the multilevel ACDF had the lowest incidence of C5 palsy. The hybrid technique can be chosen for more than two-vertebra corpectomy. In term of posterior procedures, laminectomy is safer. To prevent C5 palsy, electromyography can be used as a sensitive predictor and selective foraminotomy can be performed.