Abstract

BackgroundCan we document that posterior cervical surgery (i.e., Laminoforaminotomy (LF) and Laminectomy (L) with Posterior Fusion (PF)) exposes patients to fewer adverse events (i.e., including negligence, multiple risks, negligence, errors, and mistakes) vs. anterior cervical surgery (i.e., Anterior Cervical Diskectomy/Fusion (ACDF) or Anterior Corpectomy/Fusion (ACF))?

MethodsPosterior cervical surgery avoids many of the adverse events uniquely attributed to anterior cervical operations. These include; avoiding fusions with LF vs. ACDF for disc herniations, a lower rate of pseudarthrosis, the avoidance of direct laceration/indirect traction-related carotid/jugular vascular and/or dysphagia/esophageal injuries, fewer neural/cord injuries, vertebral artery injuries, and cerebrospinal fluid (CSF) leaks/dural tears (i.e., particularly with Ossification of the Posterior Longitudinal Ligament (OPLL)).

ResultsPosterior cervical surgery also poses no direct risks to the following anteriorly-located nerves: recurrent laryngeal nerve (i.e., vocal cord paralysis), phrenic nerve (i.e., diaphragmatic paralysis), the Vagus nerve (i.e., hypotension, reflux, arrhythmias), and sympathetic trunk (i.e., Horner’s Syndrome). However, posterior cervical surgery is generally associated with a higher risk of infection (i.e., 2-10%) vs. anterior surgery (i.e., > 1%), more posterior muscle pain, and a higher risk of kyphosis.

ConclusionsPosterior cervical surgery exposes patients to many fewer adverse events vs. anterior cervical surgery. We therefore recommend that in appropriately chosen patients, posterior cervical surgical approaches should be chosen over anterior surgery.

Keywords: Cervical Spine Surgery, Posterior, Anterior, Risks, Adverse Events, Laminoforaminotomy, Laminectomy, Posterior Fusion, Anterior Diskectomy/Fusion, Anterior Corpectomy/Fusion, Safer, Anterior Surgery-More NeuralVascular/Esophageal Injuries

INTRODUCTION

For appropriately selected patients, posterior cervical surgery (i.e., laminoforaminotomy (LF) and/or laminectomy with posterior fusion (LAMPF)) likely results in fewer adverse events (i.e., risks, negligence, errors, and mistakes) vs. anterior cervical surgery (i.e., including anterior cervical diskectomy/fusion (ACDF) and single/multilevel anterior corpectomy/fusion (ACF)) [ Table 1 ].[ 1 - 19 ] Posterior cervical operations may incur more muscular pain or kyphosis, but likely; avoid fusions for laminoforaminotomies vs. ACDF for lateral/foraminal discs, incur no direct/indirect damage to anteriorly-located carotid arteries, jugular veins, the exophagus (i.e. dysphagia/perforation), recurrent laryngeal nerve, sympathetic chain, phrenic nerve, and vagus nerve. Further, there is a reduced probability of vertebral artery injuries, cerebrospinal fluid (CSF) leaks/dural tears (i.e., especially in Ossification of the Posterior Longitudinal Ligament (OPLL)), and neural/cord injuries.

Table 1:

Summaries of studies.

Higher Risks of Adverse Events with Anterior vs. Posterior Cervical Surgery

Greater Frequencies of Adverse Events with Anterior Cervical Surgery

In their review of 240 studies (2020), Yee et al. documented a higher risk of adverse events with anterior vs. posterior cervical surgery [ Table 1 ].[ 18 ] Their (2020) meta-analysis spanning 1989 - 2019 included the following frequencies of adverse events; dysphagia 5.3%, esophageal perforation 0.2%, recurrent laryngeal nerve palsy (RLN) 1.3%, infection 1.2%, adjacent segment disease (ASD) 8.1%, pseudarthrosis 2.0 %, graft/hardware failure 2.1%, cerebrospinal fluid leak (CSF) 0.5%, hematoma 1.0%, sympathetic chain injury (Horner’s Syndrome) 0.4%, C5 palsy 3.0 %, vertebral artery injury (VAI), and other neural (i.e. phrenic nerve and Vagus nerve) and/or cord injuries/deficits 0.5%.

Higher Risk of Cerebrospinal Fluid Leak Especially with Anterior Surgery for OPLL

In Epstein’s 2024 review, the frequency of anterior cervical CSF Leaks/Dural tears with ACDF ranged from 0.25 to 1.7%, while a much higher incidence (i.e., 3.4 to 44.7%) was observed following multilevel anterior corpectomies (i.e. ACF) for OPLL [ Table 1 ].[ 9 ] Certainly, using an operating microscope reduced the frequency of anterior CSF leaks where anterior operations were warranted due to the combined presence of kyphosis/reversal of lordosis and a negative K line (i.e., pathology posterior to the vertical K line drawn from the midpoint of the C2-C7 spinal canal). Here, with a preoperative CT scan showing any one of the 3 major signs of dural penetration by OPLL, the surgeon could better anticipate and plan for an intraoperative CSF leak. Such leaks could warrant wound-peritoneal shunts, lumbar drains, and/or lumboperitoneal shunts. Alternatively, prudent spine surgeons should choose posterior surgical approaches for patients with preserved cervical lordotic curvatures, a positive K line (i.e. anterior pathology remaining anterior to the K line drawn vertically from mid C2-C7), with the additional CT evidence of likely anterior dural penetration by OPLL. Notably, spinal sureons much more rarely encounter iatrogenic CSf leaks with posterior cervical surgery. Further, with those CSF leaks, they likely occurred due to dorsolateral ossification of the yellow ligament, as anatomically, they could not be attributable to ventrally located OPLL.

Higher Risk of C5 Root Palsies with Anterior vs. Posterior Cervical Surgery

Two studies cited very high frequencies of C5 root palsies with anterior cervical corpectomy/fusion for OPLL, lesser rates for ACDF, with often reduces but occasionally variable ranges cited for posterior cervical procedures [ Table 1 ].[ 1 , 7 ] Epstein in 2015 discussed a 12% incidence of C5 root palsies occurring overall with anterior and posterior cervical surgery.[ 7 ] These were largely attributed to traction injuries and or cord migration following operative decompressions (i.e., particularly involving the C45 level). Separately reviewing posterior operations, C5 palsies for LOP ranged from 3.1-4.5%, 6.9% for posterior cervical decompressions/fusions, and up to 11.3% for laminectomy alone.[ 7 ] Notably; “...almost all studies cite spontaneous resolution of these deficits without surgery within 3-24 postoperative months”. Aiba et al. (2023) found that out of 801 consecutive patients undergoing anterior cervical surgery, the frequency of C5 palsies for OPLL patients was 12.4% (22/177 patients: mostly for multilevel anterior corpectomies) vs. 3.2% in non OPLL patients (20/624 patients).[ 1 ] At one postoperative year, only 6.1% of C5 motor palsies failed to resolve.

Higher Risk of Vertebral Artery Injuries (VAI) for Anterior vs. Posterior Cervical Surgery

Ball et al. (2024) cited an overall incidence of 0.07% for VAI in prior anterior and posterior cervical surgical studies; however, in this new meta-analysis involving 224,326 patients, the overall frequency was less than 0.03% [ Table 1 ].[ 2 ] As anticipated, The incidence of VAI was highest for anterior cervical corpectomies/fusions (ACF) at 0.06%, followed by ACDF (0.2%), with the lowest incidence being found for posterior fusions (PF) at 0.0.01%. The notable exception was for C1/C2 PF, where the frequency was the highest, ranging from 0.12 to 1.10%.

Better Results for Posterior Cervical Surgery In the Right Cervical Spondylotic Myelopathy (CSM)/OPLL Patients with Preserved Lordosis/No Kyphosis and a Positive + K Line

Several series recommended that carefully selected CSM or OPLL patients with a good lordosis/no kyphosis and a positive K line (i.e., pathology located anterior to the K line) undergo posterior cervical surgery [ Table 1 ].[ 6 , 14 , 16 , 17 ] Both OPLL and CSM pathology located anterior to the K line enable the cord to move dorsally away from anteriorly situated disease, thus resulting in adequate “decompression.” For Sehkon et al. (2006) 50 patients with CSM undergoing wide laminectomies/lateral mass fusions, patients experienced few adverse events; no deaths, no new neurological deficits, no vascular injuries, and no reoperations for residual anterior compression.[ 16 ] In 2014, Epstein observed that posterior cervical surgery avoided a multitude of risks nearly solely attributable to anterior operations; major carotid/jugular vascular injuries, esophageal traction/perforations, anterior recurrent recurrent laryngeal, phrenic, sympathetic trunk, and Vagal nerve injuries, a reduced incidence of CSF leaks/dural tears, and lesser incidence of cord/cervical root injuries.[ 6 ] In their meta-analysis of 16 studies, Wang et al. (2022) compared the safety/efficacy of LOP (Laminoplasty: 638 patients) vs. LamF (Laminectomy/Fusion: 167 patients) in patients with multilevel CSM/OPLL; the total number of adverse events was higher in the LamF vs. LOP groups, and LamF patients had more C5 palsies, plus inferior NDI (National Insurance Database) scores.[ 17 ] When McDonald et al. (2022) compared the incidence of adverse postoperative events following LOP (1420 patients) vs. LamF (10,440 patients), LOP patients experienced fewer wound problems, reduced surgical site infections (SSI), a lesser incidence of spinal cord injury (SCI), and a lower frequency of dysphagia, kyphosis, respiratory compromise, and sepsis. Notable, however, was that both LamF and LOP groups demonstrated comparable 5-year postoperative revision rates.[ 14 ]

Better Outcome for OPLL Patients with Kyphosis/Loss of Lordosis/Negative K Line Undergoing Anterior vs. Posterior OPLL Surgery

Feng et al. (2016) compared the neurological outcomes for myelopathic cervical OPLL patients undergoing anterior vs. posterior cervical surgery (1995-2015) [ Table 1 ].[ 10 ] The meta-analysis included 3 databases (PubMed, EMBASE, and the Cochran Library), and the 13 studies involve 1050 patients. Anterior operations resulted in; higher postoperative JOA scores, better postoperative neural function/neurological recovery rates (i.e., especially with canal occupancy ratios of > 50-60%, a finding consistent with a negative K line/kyphosis/loss of lordosis), higher adverse event rates, significantly higher blood loss, and longer operative times. The authors recommended anterior surgery for occupancy ratios of >50-60% (i.e., consistent with a negative K line).

Indications for Reoperations Early (/- 24 mos.) for Cervical OPLL

Ha et al. (2016) reviewed surgical revision rates for 913 patients with OPLL (1998-2012) [ Table 1 ].[ 11 ] They encountered 35 revisions; 75% of early revisions were attributed to residual stenosis whereas 25% of delayed reoperations addressed OPLL “regrowth”. The authors concluded that for patients with cervical OPLL, it is best to achieve adequate decompressions by performing initially adequate 360 anterior/posterior combined procedures.

More Postoperative Hematomas with Posterior vs. Anterior Cervical Surgery

In Chen et al. (2022) meta-analysis involving 40 studies, the overall incidence of postoperative symptomatic spinal epidural hematomas (SSEH) (i.e., exclusive of those using perioperative anticoagulation) was 0.52%: the lowest rate of 0.32% occurred in the cervical, followed by the 0.63% intermediate rate in the lumbar, and highest rate of 0.84% in the thoracic spine [ Table 1 ].[ 5 ] Notably, SSEH was more frequently encountered with posterior (0.70%) vs. anterior cervical surgery (0.24%), and were highly correlated with multilevel procedures. Interestingly, the incidence of SSEH was 5 times higher for minimally invasive (1.84%) vs. open surgical procedures (0.42%), and more occurred early vs. late (delayed).

Drains Do Not Reduce Postoperative Hematomas Following Posterior Cervical Fusions

In Herrick et al. (2018) multicenter review, drains were placed in 1180 (65.6%) of 1799 patients undergoing posterior cervical decompressions/fusions (2004-2016) [ Table 1 ].[ 13 ] The placement of drains was influenced by 2 major factors: (1) the number of surgical levels, and (2) the presence of diabetes. Although the rate of postoperative surgical site infections (SSI) was a lower 1.61% for patients with drains vs. a higher 2.58% without drains, the placement of drains did not alter the need for reoperations or frequences of postoperative hematomas (i.e., 0.68% with drains vs.o.48% without drains).

More Postoperative Surgical Site Infections (SSI) with Posterior vs. Anterior Cervical Surgery

Two studies showed higher infection rates for posterior cervical vs. anterior cervical surgery [ Table 1 ].[ 12 , 19 ] Harel et al. (2016) observed a higher risk of surgical site infections (SSI) with posterior (5.8% in 49 patients) vs. anterior cervical operations (0.5% in 192 patients).[ 12 ] The average number of levels operated upon anteriorly was 2.2 vs. a higher 3.5 levels posteriorly. Zhou et al. in a 2020 meta-analysis that included 27 studies, found the overall incidence of spinal SSI was 3.1% (603/22475 cases); 3.4% for cervical, 3.7% for thoracic, and 2.7% for the lumbar spine procedures.[ 19 ] Interestingly, 1.4% of SSI were superficial, and 1.7% were deep infections. Notably, the posterior cervical infection rate was 5% vs. 2.3% for anterior surgery. Additionally, infection rates were higher with (4.4%) vs. without (1.4%) instrumentation, but minimally invasive procedures had lower (1.5%) infection rates vs. open (3.8%) operations.

Greater Benefit for ERAS (Enhanced Recovery After Surgery) Protocols in Posterior Cervical Decompressions (PCD) vs. ACDF

Porche et al. (2023) performed a retrospective cohort analysis comparing posterior cervical decompressions (PCD: 127 patients) vs. ACDF (127 patients) [ Table 1 ].[ 15 ] ERAS protocols more significantly improved the length of stay for PCD (3.2 days) vs. ACDF (4.7 days), were correlated with respective higher home discharge rates (80% vs. 50%), and lower adverse events rates (1.1% vas. 1.8%).

Benefits of Laminoforaminotomy (LF) or Minimally Invasive Posterior Cervical Foraminotomies (MI-PCF) for Lateral/Foraminal Cervical Discs vs. ACDF

Several studies documented multiple benefits of LF or MI-PCF over ACDF [ Table 1 ].[ 4 , 8 ] In 2015, Epstein advocated for performing open cervical laminoforaminotomies (LF) to address appropriately selected lateral/foraminal cervical disc herniations rather than ACDF.[ 8 ] Open LF safely facilitated the removal of lateral/foraminal discs through wide open, direct exposures that required minimal bone resection, typically sparing the lateral 2/3 of the facet joints, and thus avoiding fusions. Further benefits of the LF over ACDF included the avoidance of major anterior vascular, esophageal, or neural structure injuries, while also reducing the risks of CSF leaks/dural tears, and cord/cervical root injuries. In 2024, Changoor et al. compared 24-month postoperative outcomes for 1-2 level ACDF (86 patients) vs. unilateral minimally invasive posterior cervical foraminotomies (MI-PCF: 66 patients) (2012-2012-2022).[ 4 ] They found ACDF required longer operative times (99.8 min. vs. 29.2 min.), and incurred more adverse perioperative events (24.5% vs. 6.2%), while ACDF vs. LF/MI-PCF patients also required more early postoperative revisions (20.7 mos. vs. 40.2 mos.). Further, only ACDF patients experienced a 20% incidence of dysphagia (20.0%).[ 4 ] The sole advantage of ACDFs was a lower operative revision rate of 1.2% vs. a much higher 13.6% rate for MI-PCF.

Posterior Cervical Surgery More Cost Effective vs. Anterior Surgery

In 2024, Broekema et al. evaluated the: “...cost-effectiveness of posterior vs. anterior surgery for cervical radiculopathy...” [ Table 1 ].[ 3 ] In this multi-center randomized trial, a total of 243 patients underwent either laminoforaminotomy vs. ACDF with a minimal follow-up duration of over 2 postoperative years. They were assessed for both cost and outcomes (i.e., VAS: Visual Analog Scale, and QUALY: Quality Adjusted Life years). Costs of average 28,046 Euros were found for posterior surgery vs. average 30,086 Euros for anterior surgery; medical costs were also lower in the posterior (12,248 Euros group) vs. anterior surgical groups (16,055 Euros). Interestingly, however, neurological outcomes were comparable for both surgical populations.

CONCLUSION

For appropriately selected patients with CSM/OPLL (i.e., adequate lordosis, no kyphosis, and a positive + K line), posterior cervical surgery will likely result in a markedly reduced incidence of postoperative adverse events vs. anterior cervical operations.

Ethical approval

Institutional Review Board approval is not required.

Declaration of patient consent

Patient’s consent not required as there are no patients in this study.

Financial support and sponsorship

Nil.

Conflict of interest

There are no conflicts of interest.

Use of artificial intelligence (AI)-assisted technology for manuscript preparation

The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.

Disclaimer

The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Journal or its management. The information contained in this article should not be considered to be medical advice; patients should consult their own physicians for advice as to their specific medical needs.

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