Asian Spine J Search

CLOSE


Asian Spine J > Volume 16(6); 2022 > Article
Kang, Jang, and Jung: Cervical Radiculopathy: Focus on Factors for Better Surgical Outcomes and Operative Techniques

Abstract

For patients with cervical radiculopathy, most studies have recommended conservative treatment as the first-line treatment; however, when conventional treatment fails, surgery is considered. A better understanding of the prognosis of cervical radiculopathy is essential to provide accurate information to the patients. If the patients complain of persistent and recurrent arm pain/numbness not respond to conservative treatment, or exhibit neurologic deficits, surgery is performed using anterior or posterior approaches. Anterior cervical discectomy and fusion (ACDF) has historically been widely used and has proven to be safe and effective. To improve surgical outcomes of ACDF surgery, many studies have been conducted on types of spacers, size/height/position of cages, anterior plating, patients’ factors, surgical techniques, and so forth. Cervical disc replacement (CDR) is designed to reduce the incidence of adjacent segment disease during long-term follow-up by maintaining cervical spine motion postoperatively. Many studies on excellent indications for the CDR, proper type/size/shape/height of the implants, and surgical techniques were performed. Posterior cervical foraminotomy is a safe and effective surgical option to avoid complications associated with anterior approach and fusion surgery. Most recent literature demonstrated that all three surgical techniques for patients with cervical radiculopathy have clear advantages and disadvantages and reveal satisfactory surgical outcomes under a proper selection of patients and application of appropriate surgical methods. For this, it is important to fully understand the factors for better surgical outcomes and to adequately practice the operative techniques for patients with cervical radiculopathy.

Introduction

Patients with cervical radiculopathy present neck and arm pain, sensory loss, motor dysfunction, and reflex changes according to dermatomal distribution. The natural history of cervical radiculopathy was generally favorable, and most studies have recommended conservative treatment as the first-line treatment [1,2]. Meanwhile, the prognosis was poor when symptoms had a longer duration, absence of paresthesia, higher neck pain intensity at baseline, higher baseline disability, and a lower active range of motion (ROM) on the symptomatic side [3].
Representative surgical procedures are anterior cervical discectomy and fusion (ACDF), cervical disc replacement (CDR), and posterior foraminotomy (PCF). Each procedure has strengths and weaknesses and is performed according to slightly different indications and contraindications. The surgery should be considered when conservative treatment fails or neurologic deficits progress.
A thorough understanding of the prognostic factors for better surgical outcomes of cervical radiculopathy is vital to improve surgical results and provide accurate information to patients. Although numerous studies for patients with cervical radiculopathy have been conducted, there is still little data for evaluating factors for better surgical outcomes. This study aims to evaluate the factors for better surgical outcomes and to learn safe and effective surgical techniques for patients with cervical radiculopathy.

Anterior Cervical Discectomy and Fusion

The ideal surgical treatment of cervical radiculopathy remains controversial. ACDF is widely used as the “gold standard.” In single-level unilateral cervical radiculopathy, a randomized controlled trial by Engquist et al. [4] demonstrated rapid improvement in neck disability, health status, neck pain, and arm pain in patients who received ACDF surgery. These scores indicated a gradual improvement from 2 to 5–8 years, although no further improvement was observed in the group that received nonsurgical treatment [4,5].

1. Indication and contraindication

ACDF is the most common procedure for symptomatic cervical radiculopathy and is not compromised by conservative treatment. Indications of ACDF include persistent and recurrent arm pain/numbness that does not respond to conventional treatment, neurologic deficits (especially definite weakness), confirmatory axial imaging studies consistent with the patient’s clinical findings, and traumatic instability. Relative contraindications of ACDF include vertebral artery anomalies (transverse foramen medial migration), retro-vertebral body compressive pathology (requiring corpectomy), and posterior neural compression [6].

2. Factors for better surgical outcomes

Iliac crest bone grafting has been considered the gold standard for intervertebral body implants. Recently, many studies have been conducted to identify alternatives to autogenous bone grafts, including allografts and synthetic and factor/cell-based grafts and cages.

1) Allo-bone grafts

Yue et al. [7] investigated the duration of ACDF maintenance using allografts and observed improvement in symptoms of neck pain and radiating pain in >95% of patients who received allograft and plating during a follow-up period of 5–11 years. A study has been conducted comparing intervertebral cages and structural allografts used in ACDF. Pirkle et al. [8] performed a retrospective analysis of 6,130 patients who underwent ACDF and investigated 2,067 patients with cage implants and 4,063 patients with allografts. When comparing the non-union rates of these two groups, the cage group (5.32%) had significantly higher non-union rates than the allograft group (1.97%) [8]. In terms of long-term prognosis, using allografts in ACDF surgery seems favorable.

2) Cage implants

Many studies have compared cage materials, polyetheretherketone (PEEK), titanium (Ti), carbon fiber-reinforced polymers, and polymethyl methacrylate. PEEK and Ti cages have relatively superior clinical outcomes, higher fusion rates, and lower subsidence rates than others. No significant differences in the fusion rates were observed between Ti and PEEK [9,10]. Meanwhile, an absorbable cage using polylactic acid–polyglycolic acid polymers theoretically has advantages, such as immediate postoperative stability and gradual disintegration to aid bone formation and solid arthrodesis. Still, its effectiveness has not been fully demonstrated [11].
PEEK has a radiolucent nature and an elastic modulus similar to the bone, and many surgeons use PEEK plastic cages during ACDF. It has a high fusion rate, low subsidence, and stability provided by the cage, and it facilitates radiographic outcomes [12]. A long-term clinical study has revealed that PEEK has some limitations, such as endplate erosion. Recent cage designs have attempted to promote early osteointegration to achieve postoperative stability and reduce complication rates. Ti could modify the surface roughness of the cage. Hence, a Ti/PEEK combined cage was created, which has both the good bioactivity of Ti and the elastic modulus of PEEK [13,14]. However, the efficacy of Ti/PEEK combined cages remains controversial, warranting long-term and extensive clinical studies.
Recently, porous three-dimensional (3D) printed Ti cages (3DTC) have been considered an option for interbody implants. 3DTC has advantages over PEEK cages in a highly porous architecture mimicking cancellous bone, which promotes bone ingrowth. Additionally, the relatively wide range of cage sizes compared to those of standard allo-bone grafts may lead to better axial load sharing and a low subsidence rate. Comparing patient groups using 3D printed cages and allografts in ACDF, 3DTC yielded similar clinical results and fusion rates to allografts but lower subsidence rates at all times [15].

3) Spacer location

When inserting a cage for ACDF, proper size, proper location, preservation of the anterior cortical bone, and proper endplate preparation are effective in preventing subsidence and secondary kyphotic deformities [16]. In ACDF surgery, implant subsidence is crucial in determining the prognosis. In a study, surgery was performed using single-level ACDF with allografts and plates, and a retrospective study on the occurrence of subsidence was conducted. They were divided into two groups based on the allograft position: an anterior group with the allograft within 2 mm of the posterior margin of the plate and a center group with the allograft at >2 mm. The subsidence rate was 8/73 (11%) in the anterior group and 7/19 (37%) in the center group, thus indicating that the subsidence rate was lower when the allograft position was anterior [17].
Similar results were obtained for the ACDF using cages. Mende et al. [18] classified the location of the PEEK cage in the sagittal plane as ventral (anterior), central, or dorsal (posterior). Considering that all used the same rectangular PEEK cage devices, the subsidence rate decreased when placed more ventrally. The rectangular cage should be placed ventrally, although the cage was often located in a different place during surgery; only 13% of the cages were generally located in the ideal position [18] (Table 1). Barsa and Suchomel [16] and Yamagata et al. [19] also described that the subsidence rate increases as the cage is positioned away from the ventral border of the vertebra.

4) Spacer size and height

The cage/endplate ratio (=cage long length/endplate length in the sagittal plane) was confirmed to affect subsidence after ACDF. When the cage size was ≥65% of the endplate diameter measured in the sagittal plane, the subsidence rate decreased rapidly after ACDF. Therefore, when determining the cage size, a cage with a cage/endplate ratio of ≥65% can be considered to lower the subsidence rate caused by axial compression force [18].
Studies analyzing cage height and subsidence risk are limited. In one paper, the subsidence rate was significantly higher when using 6.5 or 7.5 mm than when using 4.5 mm or 5.5 mm [19]. Thus, a larger cage height is associated with subsidence because a larger height may result in larger stress on the vertebral endplate. Truumees et al. [20] have demonstrated that distraction increases can contribute to graft failure, subsidence, and non-union by increasing the pressure load on the endplate. An et al. [21] conducted a cadaveric study. When the baseline disc heights were 3.5–6.0 mm, 2–3 mm of distraction from patients’ original disc height was desirable for obtaining maximal change in foraminal size [21]. On the other hand, Lawless et al. [22] demonstrated in a recent systematic review that increasing up to 8 mm in interspace height during ACDF did not show a significant difference in fusion rate, postoperative Neck Disability Index (NDI), Visual Analogue Scale (VAS), and 12-item Short Form Health Survey score. Although there are no established results yet, the spacer size and height will affect the surgical outcomes of ACDF, and additional research is still needed on the exact relationship.

5) Plating

Cheung et al. [23] conducted a systematic review and meta-analysis to compare cage-only and traditional cageplate techniques. The cage-only technique is advantageous for reducing postoperative dysphagia, and adjacent segment disease (ASD) compared to the cage-plate technique. Meanwhile, the cage-plate technique is advantageous in reducing cage-subsidence and pseudarthrosis incidence rates, maintaining postoperative disc height, and restoring cervical lordosis [23]. Lee et al. [24] conducted a study on factors affecting subsidence after ACDF surgery. They confirmed that ACDF with plating lowers the incidence of subsidence postoperatively regardless of the kyphotic/lordotic cervical alignment preoperatively.
When comparing the types of cervical plates used, no significant difference was observed in the use of fixed-hole (static)-type plates and slotted-hole (dynamic) types for a single level. However, Nunley et al. [25] concluded that a dynamic-type plate is more effective in multilevel ACDF. In their study, although single-level ACDF was more effective than multilevel ACDF for pain relief, the VAS and NDI scores of the dynamic-type plate group were low in the multilevel ACDF.

6) Bone mineral density

Using biomechanical destructive compression tests, Lim et al. [26] reported that as bone mechanical strength was known to increase along with bone mineral density (BMD), vertebral BMD could be considered an essential factor in predicting the mechanical strength of the cage– endplate interface. Pinter et al. [27] investigated the role of BMD in patients while studying the risk factors for pseudarthrosis that may occur after ACDF. Data from 79 patients who underwent 1- to 4-level ACDF at a single research institute were retrospectively reviewed. At 1 year postoperatively, 65 patients (82%) achieved successful union; however, pseudarthrosis was confirmed in 14 patients (18%). When the pseudarthrosis subgroup was compared with the fusion subgroup, the pseudarthrosis subgroup demonstrated a significantly lower BMD (hip T-scores: −1.4±1.2 versus −0.2±1.2 and spine T-scores: −0.8±1.8 versus 0.6±1.9). Also, osteopenia, not osteoporosis, can increase the risk of pseudarthrosis after ACDF surgery. Hence, surgeons should consider the patients’ BMD when planning surgery [27].

7) Patient factors

Complete fusion of the segment after ACDF surgery is important for long-term prognosis. The surgeon should consider the instruments and techniques used during the surgery and the patients’ factors.

(1) Diabetes and smoking

Diabetes and smoking are worse prognostic factors that have been well-documented in the past. When comparing the frequency of non-union after ACDF surgery in patients with diabetes, the incidence of non-union was 1.7 times higher in the allograft group and 2.2 times higher in the cage group [8]. Cancienne et al. [28] reported that patients with diabetes are not a contraindication for single-level ACDF. Still, there is a significantly increased risk of deep postoperative infection when the perioperative hemoglobin A1c level exceeds 7.5 mg/dL [29].
Several studies have reported that tobacco use interferes with the bone union, and the incidence of non-union was approximately 2.6 times higher in the allograft group [8]. Cerier et al. [30] reported that smoking could affect the postoperative improvement in NDI scores in 2-level ACDF.

(2) Body mass index

Perez-Roman et al. studied the postoperative complication rate and surgical outcomes of ACDF associated with obesity status. In their analysis, obese patients with a body mass index (BMI) of 27.5 kg/m2 or more were found to have significantly higher rates of pulmonary embolism, wound infection, as well as dysphagia, neurological, cardiac, respiratory, hematological, and genitourinary complications [31]. Wang et al. [32] found that the patients who complained of immediate postoperative swallowing difficulties showed a higher BMI than the others (27.3 kg/m2 versus 24.6 kg/m2).

(3) Vitamin D

Vitamin D is well-documented to play an important role in bone metabolism. Some studies have confirmed that vitamin D deficiency can affect the outcomes of spinal fusion surgery. Khalooeifard et al. [33] conducted a meta-analysis and showed poor prognosis after surgery in patients with vitamin D deficiency (4.82 times Oswestry Disability Index increase).

(4) Steroid use

Several studies showed the risk factors for complications after cervical spine fusion surgery. They confirmed that long-term steroid use could increase the risk of pseudarthrosis after surgery (odds ratio [OR], 1.89) [34] and postdischarge complications (OR, 1.76) [35].

3. Interesting topics for anterior cervical discectomy and fusion

1) Bone morphogenic protein in cervical spinal surgery.

In 2008, the Food and Drug Administration (FDA) warned against the use of bone morphogenic protein (BMP) for anterior cervical surgery. The overall complication rate was higher at 2.1% with BMP than without BMP (1.9%). More wound complications were also noted [36]. However, low-dose BMP has been used in contemporary clinical practice because of its several advantages. Mendenhall et al. [37] reported that using low doses of recombinant human BMP (rhBMP)-2 safely and effectively increased the fusion rate of anterior cervical fusion. In this study, 190 (96%) of 198 patients who received rhBMP-2 demonstrated firm joint union after 15 months. Additionally, the same level of coalescence in smokers, patients with multi-segmental ACDF, and those at high risk of pseudarthrosis was observed, suggesting that rhBMP-2 effectively increases the postoperative union rate [37]. The postoperative complication rate may increase when BMP is used to correct cervical deformity through an anterior surgical approach; however, the rate of subsequent revision surgery decreases [38,39].

2) Total uncovertebrectomy

(1) Literature

A technique of uncinate process resection during ACDF surgery was introduced and developed to achieve complete and direct decompression for severe bony foraminal stenosis. Total uncovertebrectomy originated from anterior cervical foraminotomy for unilateral cervical radiculopathy [40,41], and its safety and efficacy were evaluated in ACDF surgery [42]. In 2017, Lee et al. [43] conducted a study on the effectiveness and risk of uncinate resection during ACDF surgery. They reported that the uncinate resection group demonstrated faster clinical improvement than the non-uncinate resection group. Moreover, the fusion rates of both groups were comparable. Safaee et al. [44] have revealed detailed techniques of ACDF with uncinectomy and proved the safety and efficacy of direct anterior nerve root decompression. Among the 91 patients of myotome-specific weakness treated with uncinectomies, 80 (88%) improved, 10 (11%) had no change, and 1 (1%) worsened at the 6-week follow-up visit. Among 66 uncinectomies performed for dermatome-specific numbness, 57 (86%) were associated with complete resolution, and 9 (14%) demonstrated no improvement at 6 weeks. No patient developed worsening sensory symptoms [44]. Meanwhile, although a study has reported a significant correlation between uncinate process resection and subsidence during ACDF, Ferrete-Barroso et al. [45] have reported good results of anterior cervical arthrodesis using autograft bone originating from a total uncinate process resection.

(2) Surgical techniques

The critical point of this technique is the protection of the vertebral artery, which is located at the lateral aspect of the uncinate process. After dissection and coagulation of the longus coli muscle’s undersurface, the uncinate process’s lateral border is identified and gently detached from the soft tissue with the vertebral artery using a Penfield dissector. The end tip of the probe is maintained to avoid going deep and damaging the nerve root. Two uncinate resection techniques have been known. First, using a burr with a large matchstick head, the uncinate process is removed gradually from the inside at full height. If the lateral cortex of the uncinate process is sufficiently thin to move, the remaining fragment of the uncinate process can be easily fractured and removed. Second, using a slight head matchstick burr, the bottom of the uncinate process is removed from the medial side. If the remaining uncinate process is sufficiently removed to move, the whole fragment can be removed by breaking the left outer part using a small osteotome. The bone dust and fragment from the operation field can be used as bone grafts (Fig. 1).

4. Summary

Historically, ACDF surgery has been widely used in patients with cervical radiculopathy and has proven its safety. Many studies have been conducted to improve the prognosis of ACDF surgery. From what has been confirmed thus far, the allo-bone graft demonstrates better results than other spacers. Additional research on the effectiveness of cages is needed, but the prognosis of PEEK and Ti cages is relatively favorable to date. During spacer insertion, using a cage with a cage/endplate ratio of ≥65% and positioning it close to the anterior cortical bone helps to lower the subsidence rate. The use of a plate has the possibility of complications caused by the plate, although it may decrease subsidence. Thus, the pros and cons of its use should be considered. The preoperative conditions of patients should also be considered. Determining bone quality, the presence of diabetes, and smoking status in advance is crucial as such factors can affect the postoperative prognosis. There has been controversy over the use of rhBMP-2, but recently, a method of using rhBMP-2 at a low dose to reduce side effects has been attempted in consideration of the advantages of rhBMP-2.

Cervical Disc Replacement

To date, the most common surgical method for cervical disc herniation is ACDF, but it has a limitation that causes ASD [46]. Therefore, CDR was devised as a surgical procedure to preserve joint mobility [47,48].

1. Indication and contraindication

The indications for surgery approved by the FDA include level 1 or 2 segment cervical degenerative diseases or disc herniation and foraminal osteophytes that cause radiculopathy or myelopathy in adult patients [49,50]. Contraindications include osteoporosis or metabolic bone disease, active or prior infection, ankylosis, congenital cervical stenosis, facet arthritis, and segmental cervical instability. Pimenta et al. [51] presented instability as an exclusion criterion for CDR in a study comparing the outcome of multilevel cervical arthroplasty with single-level surgery, which was defined as anterior subluxation of 3.5 mm or more in flexion-extension radiographs. Additionally, because of the stability of the prosthesis, the posterior structure must be structurally and functionally intact. Therefore, previous laminectomy or excessive facet removal is contraindicated [49]. Ossification of the posterior longitudinal ligament (PLL), renal failure, cancer, rheumatoid arthritis, diffuse idiopathic skeletal hyperostosis, and preoperative corticosteroid medication should also be avoided [52].

2. Factors for better surgical outcomes

1) Implant type

CDR was devised to reduce the occurrence of ASD during long-term follow-up by maintaining the motion of the cervical spine, and it can be categorized as constrained, unconstrained, or semi-constrained. The term constraint refers to the kinematic degree of freedom of an object in a 3D space in biomechanics and is classified as above according to the degree of motion in a CDR device [53]. The unconstrained types include the Bryan, Mobi-C, PCM, and Prestige LP, which may cause sagittal malalignment, including kyphosis or hypermobility due to lack of constraint. The semi-constrained types include the ProDiscC, Prestige ST, Simplify, M6, and Secure-C, which are known to demonstrate similar results to those of the unconstrained types. Recently, a patient-specific device using 3D printing has been introduced, which may have a better effect on patient outcomes in the future [49,54].

(1) Unconstrained types

The Bryan disc is a bi-articulation device comprising a polyurethane center and two Ti endplates, which induce bony ingrowth through a porous surface and provide stability. This prevents posterior dislocation of the device through the anterior flange. The polyurethane center is enclosed with a saline-filled sheath, which forms a pseudocapsule, and the cushioning effect of the actual disc is expected [49]. The Mobi-C disc comprises three components. The two endplates were made of cobalt, chromium, and 29 molybdenum ISO (International Organization for Standardization) 5832-12 alloy, and each line with teeth was on its outer edge. The internal contact surface of the inferior end plate is spherical, and the superior end plate is flat [49,55].

(2) Semi-constrained types

The ProDisc-C disc comprises two components of ball- and-socket, and the porous endplate is made of cobalt chrome. The medial surface of the inferior endplate is convex, and the insert surface articulating with the superior endplate is concave; therefore, translation was limited, and rotation was allowed in all three axes. The outer surface of the implant was coated with Ti [49]. Prestige ST has a ball-and-trough design, and dual-screw fixation is performed on each adjacent vertebral body. It is composed of stainless steel containing iron, carbon, nickel, molybdenum, and chromium [49,56]. The M6 disc is a single piece with a complex centerpiece composed of Ti alloy endplates and polycarbonate urethane polymeric material. This material serves as the nucleus pulposus and is surrounded by polyethylene woven fibers that serve as the annulus fibrosis. The polymer sheath prevents infiltration of debris and ingrowth of tissues [49]. The Secure-C disc comprises three components. The two endplates were keeled porous-coated cobalt chrome with an ultrahigh molecular weight polyethylene sliding center. The upper side of the center was spherical, whereas the lower side was cylindrical. This allowed for anterior–posterior (AP) sliding and physiological loading, simultaneously causing movement of the axis of rotation in the sagittal plane. It also prevents the core from leaving and protecting the facet from excessive loading [49,57] (Table 2).

2) Implant size and height

Selecting the appropriate size, shape, and height of the artificial disc can produce good results for the patient; however, size and height are critical. Suppose the height of the device is approximate ≥2 mm than the standard value. In that case, it can cause a significant change in the stress of the cervical biomechanics and bone-implant interface, which can cause ASD or subsidence [58]. The device’s height is higher than normal; massive stress is applied to the disc, resulting in a shortened lifespan. However, if the device’s height is short, cervical kyphosis or a decrease in flexion motion may occur. Therefore, adjusting the device’s size is necessary to prevent compressing the spinal canal or exceeding the anterior margin of the disc space. Additionally, if the device is small, early subsidence or stress concentration on the small surface may cause early wear. Thus, a device that can cover the endplate within 1–2 mm of the original vertebral body should be selected [59]. The appropriate implant size is finally determined through trial, and the AP and lateral images are checked. In many patients, the uncus can be asymmetrical, in which case the implant can shift laterally, even if it fits into the midline of the disc. In this case, one can select a smaller implant, remove the protruding uncus, and repeat the procedure [59,60].

3) Location of implant

After applying the implant to the disc space, fluoroscopic imaging should confirm proper positioning [54,61]. The proper position of the device in the coronal plane is to check the line connecting the spinous process that is projected with the center of the stone connecting the unit on fluoroscopy. In the sagittal plane, the device is placed perpendicular to the posterior wall of the vertebral body at the level to be operated on, passing through the center of rotation (COR) of the CDR [62].

4) Preservation or removal of the posterior longitudinal ligament

The preservation and removal of PLL during CDR surgery in patients with cervical radiculopathy remain controversial. Depending on the surgeon’s choice, the PLL can be removed or released, which can be influenced by device type. There are advantages and disadvantages to preserving and removing the PLL. The hypotheses that preserving the PLL can maintain adequate cervical ROM and that removing the PLL can cause hypermobility are conflicting [54]. Voronov et al. [63] have suggested that hypermobility can be solved by applying a stiffer device during device implantation. Kim et al. [64] also mentioned that PLL is already damaged in case of severe herniation of the disc material, so it is removed only in this case. Some surgeons consider PLL removal the best means to ensure sufficient decompression [54].

5) Patient factors

Selecting an appropriate patient group is important to attain a good prognosis in CDR. Patients with one or two-segment radiculopathy or myelopathy caused by soft disc herniation with physiological motion have an excellent postoperative prognosis. Selecting patients without osteoporosis, hypermobility, kyphosis, or scoliosis is advantageous [59].

(1) Smoking

Tu et al. [65] compared clinical and radiologic outcomes by dividing 109 patients who underwent CDR into the smoking group (20 patients) and the non-smoking group (89 patients). In this study, while no significant difference in clinical outcomes was observed between the two groups, a significant difference in segmental ROM in the smoking group was observed (8.1°→8.1° versus 8.2°→6.9°). Although no significant difference in the generation of heterotopic ossifications (HO) (50.0% versus 59.6%) was observed, the smoking group demonstrated a relatively low incidence rate [65].

(2) Others

Zeidan et al. [66] analyzed factors affecting readmission or prolonged length of stay after CDR. The factors influencing readmission were postoperative superficial wound infection (OR, 73.83), American Society of Anesthesiologists (ASA) classification (OR, 1.98), and BMI (OR, 1.06). The factors affecting the prolonged length of stay were female sex (OR, 1.76), diabetes (OR, 1.50), postoperative wound dehiscence (OR, 13.11), ASA class (OR, 1.43), and operative time (OR, 1.01) [66].

3. Surgical techniques: proper patient’s position and sizing and settling of the implant

The patient is placed in a supine position with the head in a neutral position and is secured to the operating bed with tape on the forehead to prevent the head from moving during the operation. To prevent the shoulder from overlapping with the cervical vertebrae during radiography, the tape is attached and fixed by pulling it toward the patient’s foot. Also, position the patient so the end plate of the area can be operated on in parallel [67].
To prevent the formation of HO, a unique complication of cervical arthroplasty, the use of drills should be reduced as much as possible [49,67]. In CDR, implant sizing and centering are the most important factors [68]. Under a fluoroscopic device’s operation, an appropriate size implant is selected and inserted. At this time, centering is confirmed through the AP and lateral radiographs [67]. Placing the device’s COR slightly behind the midline of the intervertebral disc space provides a better combination of the actual segment’s COR and the device’s COR. Many surgeons prefer this because it can reduce the occurrence of subsidence. After all, the strong posterior rim of the end plate holds up [61,69].

4. Interesting topics for cervical disc replacement

1) Hybrid surgery

Recently, the number of hybrid surgeries in which ACDF and CDR are performed together has increased in patients with multilevel cervical degenerative disc disease [70]. This is suggested when it is challenging to apply fusion or arthroplasty equally to all levels because the degree of degeneration at each level is different. This is known to limit the hypermobility of adjacent segments while maintaining the segmental motion of each segment, and several studies have reported better results with combined ACDF and CDR than with ACDF or CDR alone. Moreover, the postoperative assessment, complication rate, and functional score have been reported to be excellent or similar. Whether the arthroplasty level was above or below the fusion level did not indicate a significant difference in motion, pressure applied to the adjacent disc, or facet joint force [71,72]. Jia et al. [71] have reported that complications included dysphasia, heterotropic ossification, and vocal cord paralysis during hybrid surgery, and no non-union occurred. This is expected to cause less non-union as more ROM remains in the segment during hybrid surgery, which has the effect of applying less stress to the adjacent level. A comparative study should be conducted to determine whether hybrid surgery has fewer non-union occurrences than ACDF does.

2) Long-term results of cervical disc replacement

Compared with ACDF, CDR has a lower reported incidence of ASD and a lower reoperation rate due to improved ROM. However, some studies have reported that ROM may decrease owing to heterotropic ossification, mechanical malfunction of the device, or implant wear. As a result of comparing several studies, Hence, Zavras et al. [73] reported that ROM immediately postoperatively improved compared to ROM preoperatively, and no significant change in follow-up up to 1 year was observed. However, in the long-term follow-up (average, 99.86 months), the ROM deteriorated significantly, and efforts to maintain a good long-term ROM were necessary [73].
Burkus et al. [74] confirmed the 7-year outcome of the CDR group using the Prestige ST device, and all demonstrated promising results. Especially when compared to ACDF, NDI score, neurologic status, and revision rate due to ASD have good results. A study by Gornet et al. [55] also demonstrated a similar conclusion to the abovementioned study comparing the ACDF group in the 7-year outcome after CDR using the Prestige.

5. Summary

CDR is an operative treatment for patients with cervical radiculopathy that reduces the incidence of ASD during long-term follow-up by maintaining cervical spine motion postoperatively. Various devices classified as constrained, unconstrained, or semi-constrained are selected according to the patient’s condition and the operator’s preferences. Selecting an artificial disc of an appropriate size, shape, and height and inserting it into an ideal position is a decisive factor in achieving a good patient prognosis. Selecting patients with level 1 or 2 segments of cervical degenerative disease or disc herniation who do not correspond to the abovementioned contraindications is also essential. Recently, topics of interest have focused on hybrid surgery, which involves performing ACDF and CDR together, and the long-term consequences of the CDR.

Posterior Cervical Foraminotomy

PCF is a safe and effective surgical method for treating patients with cervical radiculopathy [75,76]. PCF avoids complications of anterior surgery, such as postoperative hematoma, dysphagia, and recurrent laryngeal nerve palsy [75,77]. Additionally, since fusion is not required, fusion-related side effects such as pseudoarthrosis and instrumentation failure do not occur. However, its disadvantage is that considerable posterior muscle damage is possible, and the rate of reoperation is higher than that of ACDF because fusion is not performed [78-80].

1. Indication and contraindication

The indications for PCF are relatively narrow compared with those of the other surgical methods. It is commonly performed in patients with level 1 or 2 unilateral radiculopathies [81]. Moreover, it is appropriate only when foraminal stenosis is clearly confirmed on magnetic resonance imaging and when nerve root compression caused by soft lateral disk herniation and corresponding radicular symptoms are present [82]. Meanwhile, if cervical instability is confirmed by stress X-ray, PCF is contraindicated. Additionally, myelopathy or central stenosis is caused by extensive spondylotic disease and diseases caused by comprehensive anterior disc or osteophytes [81-83].

2. Factors for better surgical outcomes

To improve the postoperative prognosis of patients, selecting the right patient for PCF is important. The main symptoms, such as arm and neck pain, are generally reduced postoperatively [82]. Skovrlj et al. [84] have reported significant improvements in both NDI and VAS postoperatively compared to that preoperatively, and Church et al. [85] have reported >85% improvement in pain, weakness, and function in a 10-year follow-up study postoperatively. Witzmann et al. [86] showed excellent functional and economic results in 90% of patients. The study by Holly et al. [87], comparing the group that underwent multilevel surgery and the group that underwent single-level surgery, showed similar results. Meanwhile, in a large cohort study by Church et al. [85], they concluded that radiculopathy due to soft disc subtypes might be associated with a better prognosis compared to osteophyte disease, although osteophyte disease remained an excellent indication for PCF.

3. Detailed techniques of posterior foraminotomy

Since Zdeblick et al. [88], in their biomechanical study, had demonstrated that torsional stiffness dramatically decreased when ≥50% of the facet was removed, and posterior strain significantly increased at 75% or 100% facet resection compared to the intact case, resection of ≥50% of the facet was considered to cause cervical hypermobility. The first step in PCF is to resect the medial 1/2 of the facet joint to decompress the cervical nerve root [89]. Accurately marking the medial 1/2 of the facet joint is necessary. In a cadaveric study, Barakat and Hussein [90] reported that the horizontal distance from the medial point of the facet joint to the lateral surface of the dura after medial 1/2 facetectomy was 7.1–9.8 mm, and Hwang et al. [91] mentioned that the mean distance of the exposed root was 8.2–9.0 mm. Therefore, approximately <10 mm (mediolateral) laminoforaminotomy is considered a proper length. To avoid cervical instability, the facet should be resected to <50%, and for this, removing up to 5 mm of the lateral mass is considered safe [92-95].
When decompressing the nerve root, identifying the difference in the anatomical relationship between the nerve root and disc at each cervical level is necessary. In particular, in the case of C8, the frequency of radiculopathy is relatively lower than those of the other levels due to the transverse course of the nerve root. Therefore, when performing decompression of the C8 nerve root, more extensive decompression should be performed on the proximal and lateral parts [96].
During PCF, the most technically demanding aspect is bleeding control for a clear view. To decrease intraoperative bleeding and minimize facet joint damage, the authors usually perform the PCF using an en-bloc resection technique. This technique proceeds in the following order. First, the inferior articular process is removed, and a cutting groove is made at the superior articular process (SAP), which proceeds from the transverse direction to the vertical direction. After making shallow transverse and vertical grooves in the medial half of the SAP, this cutting groove is made more profound, and then the bony fragment is twisted using a small osteotome. Because we can hear a clicking sound, this technique is called the “click method.” Finally, the en-bloc fragment can be detached and removed using a micro-curette (Fig. 2).

4. Interesting topics for posterior foraminotomy

1) Endoscopy

PCF using endoscopy is widely performed. This method demonstrates clinical and radiological results similar to the open technique and has the advantage of minimizing complications compared to the open technique [97-99]. Additionally, studies have reported reduced surgery time, shortened hospitalization period, and quicker return to daily life [100-102]. The surgical indication for cervical foraminotomy using endoscopy is similar to the conventional method, although this should be avoided when the spinal cord is compressed [103]. Recently, anterior foraminotomy with endoscopy has been performed in patients with cervical radiculopathy to protect the intervertebral disc and maintain the functional motion segment during surgery. Kabil and Abdel-ghany [104] performed microendoscopic anterior cervical foraminotomy in patients with unilateral radiculopathy with single levels of soft disc herniation or hard disc osteopathy and have reported the clinical outcomes. In this study, patients demonstrated excellent postoperative results in most clinical outcomes, including neck pain and arm pain, were able to perform neck movements immediately after surgery and did not require cervical collars.

2) Posterior foraminotomy with laminoplasty

Sasai et al. [105] have reported that microsurgical PCF with laminoplasty produced good results in patients with cervical spondylotic radiculomyelopathy. Lee et al. [106] and Liu et al. [107] have also reported that laminoplasty with PCF could be an efficient and safe treatment for patients with combined myelopathy and radiculopathy. Komagata et al. [108] have reported that performing expansive laminoplasty and foraminotomy simultaneously in patients with cervical spondylotic myelopathy or ossification of the PLL helped prevent C5 palsy. Recently, the importance of this PCF procedure may be increasing in patients who undergo laminoplasty for cervical myeloradiculopathy.

3) Long-term results

Heo et al. [109] performed a long-term follow-up of 46 patients who underwent PCF surgery for 74.4 months. Among them, 39 (84.7%) and 25 (71.4%) showed improvement in radiculopathy and neck pain, respectively, and excellent clinical results were confirmed. Bielecki M et al. [110] followed up 48 patients who underwent PCF surgery for 100.8 months and confirmed that the NRS arm, NRS neck, and NDI scores improved by 7, 4.5, and 24 points, respectively, and reported that radiological results also improved in 82%.
MacDowall et al. [111] have reported in a review article that, as a result of comparing the PCF group of 647 patients and the ACDF group of 3,721 patients, there was no significant difference in NDI scores, EuroQol-5 dimension, and VAS for neck and arm scores at 5 years after surgery. From this, it can be assumed that PCF surgery shows excellent clinical and radiological results in long-term follow-up. Its excellence is not inferior even when compared with ACDF [111].

5. Summary

PCF is a safe and effective surgical method to avoid complications associated with fusion and possible anterior surgery in patients with cervical radiculopathy. The indications for PCF are relatively narrow compared to those of other surgical methods, commonly in patients with level 1 or 2 unilateral radiculopathies. Recently, endoscopic surgery, which can minimize complications compared to open surgery, has attracted increasing attention. Endoscopic surgery reduces operative time, shortens the length of hospital stay, and expedites the return to daily life. Long-term follow-up of PCF surgery shows excellent clinical and radiological results, and its excellence seems not to be inferior to other surgical methods.

ACDF versus CDR versus PCF

1. ACDF versus CDR

Findlay et al. [112], in a review study of 22 papers with 3,160 patients, compared long-term outcomes after ACDF and CDR and found no significant difference between the two groups in short-term outcomes up to 2 years. However, in the 4th and 7th-year comparisons, the CDR group was superior to the ACDF group in most items, such as NDI, 36-item Short Form Health Survey, dysphagia, and satisfaction (overall success results favored CDR; relative risk=0.60) [112]. Comparing the postoperative ASD incidence, in most cases, the CDR group showed a lower incidence of ASD than the ACDF group. In particular, in a study by Zhong et al. [113], the incidence of ASD in the CDR group was significantly smaller than that in the ACDF group (3.0% versus 8.0%). In a 7-year follow-up study by Janssen et al. [114], the incidence of ASD in the CDR group was significantly smaller than that in the ACDF group (5.8% versus 12.2%). To date, particularly in medium- to long-term follow-up, the rate of symptomatic ASD seems to be lower in the CDR group than in the ACDF group [55,74,113-125].

2. ACDF versus PCF

MacDowall et al. [111] compared the outcomes of ACDF and PCF in a population-based large cohort (4,368 patients). Although they have reported that both groups demonstrated clinical improvements at the 5-year follow-up that did not achieve a clinically significant difference from one another, the secondary surgeries on the index level due to restenosis were more frequent in the foraminotomy group and on the adjacent segments, there was no difference between groups. In a study comparing minimally invasive PCF using tubes and ACDF, Dunn et al. [126] showed no difference in overall revision proportion between the two groups. Also, there was no significant difference in NDI and VAS scores before and after surgery. In a select group of patients, PCF and ACDF demonstrated similar surgical outcomes to those of surgical treatments for cervical radiculopathy.

3. Reoperation

The main issue of CDR is to leave motion of the cervical spine. Therefore, good candidates for CDR are young patients whose basic cervical spine movements are well preserved. When referring to knee and hip artificial joint surgery, the survival rate of artificial joints is 91% at 10 years and 78% at 20 years [127]. It can be interpreted that young patients will undergo revision surgery at least once in their lifetime. Joaquim et al. [128] conducted a systematic review on patients undergoing reoperation due to CDA failure. During the 5-year follow-up period, the CDA failure rate at the index level was 3.9%, and ACDF was the most frequently performed salvage surgery for failed CDA. Reasons for reoperation include worsening of symptoms, persistent neck or arm pain, disc subluxation, postoperative myelopathy, oversized implant, mal-positioned implant, and iatrogenic fractures of the posterior vertebral wall [128].
Wang et al. [129] investigated 178 patients who underwent PCF surgery for 31.7 months and found that only 9 (5%) received revision ACDF in the segment where PCF was performed. Patients who received revision ACDF were younger on average (25 years versus 35 years), had a lower BMI (25 kg/m2 versus 29 kg/m2), and were more likely to take anti-anxiety (56% versus 22%) or antidepressants (67% versus 27%) medications compared to those who did not undergo revision ACDF surgery [129]. Lubelski et al. [75] compared the revision surgery rate of ACDF and PCF within 2 years of the initial surgery, and there is no significant difference between them (4.8% for ACDF versus 6.4% for PCF). Meanwhile, suppose a patient complains of radicular symptoms after CDR. In that case, the implant is positioned well, the canal is decompressed well, and the radicular symptoms derived from foraminal stenosis or disc herniation, PCF can be performed. The appropriate subjects for this operation are the patients who show Spurling signs positive and symptoms of improvement when the neck flex forward. The Spurling method narrows the foramen, causing symptoms of nerve compression, and the forward flexion plays a role in alleviating the symptoms by expanding the size of the foramen [130].

Conclusions

Numerous studies on patients with cervical radiculopathy have been performed, but the data on analyzing factors for better surgical outcomes are still confusing. In this study, a detailed description of three surgical methods for patients with cervical radiculopathy and a comprehensive analysis of factors for better surgical outcomes were conducted. In the ACDF surgery, allo-bone graft, cage implants, spacer location, spacer size and height, plating, BMD, and other factors (diabetes and smoking, BMI, vitamin D, steroid use) can be important factors for better surgical outcomes. In the CDR surgery, type, size, height, location of the implant, PLL preservation or not, and other patient factors (smoking, ASA classification, BMI, etc.) are considered significant prognostic factors. In PCF surgery, the patient’s selection for proper indications and subtypes of the soft or hard disc is critical for postoperative surgical outcomes.
Most of the recent literature demonstrated that all three surgical techniques (ACDF, CDR, and PCF) for patients with cervical radiculopathy have clear advantages and disadvantages and reveal satisfactory surgical outcomes under a proper selection of patients and application of appropriate surgical methods. Meanwhile, exciting topics for the ACDF surgery include the usage of BMP and total uncovertebrectomy or not, and interest in the long-term results of the CDR surgery compared to the ACDF and hybrid surgery (combined surgery of ACDF and CDR) is increasing. In PCF surgery, endoscopic surgery and long-term results are recently interesting. For this, it is important to fully understand the factors for better surgical outcomes and to adequately practice surgical techniques for patients with cervical radiculopathy.

Conflicts of interest

No potential conflict of interest relevant to this article was reported.

Notes

Author Contributions

Conceptualization: KCK and TSJ; data curation: KCK and CHJ; funding acquisition: KCK; methodology: all authors; project administration: KCK; visualization: KCK; writing–original draft: all authors; writing–review & editing: all authors; and final approval of the manuscript: all authors.

Fig. 1.
Scheme illustrating surgical techniques for total uncinate process resection. First, vertebral artery (*) is secured by gently placing the Penfield dissector (★) between the lateral margin of the uncinate process and soft tissue containing the vertebral artery. (A) Using a burr with large matchstick head (3.0 mm, ▷), the uncinate process is removed medially to laterally until the lateral wall becomes sufficiently thin (→) enough to be moved. (B) Using a burr with small head (1.8 mm, ▶), only the bottom of uncinate process is resected and the remained fragment can be easily removed without any complications (dotted rectangle: directly removed part by a burr).
asj-2022-0445f1.jpg
Fig. 2.
Scheme illustrating surgical techniques for posterior cervical foraminotomy using en-bloc resection. (A) Inferior articular process removal, (B) superior articular process (SAP)-transverse cutting groove, (C) SAP vertical cutting groove, (D) groove deepening, (E) fragment twisting with a small osteotome, named ‘click method,’ and (F) fragment detaching and removal with a microcurette. Ca, caudal; Sp, spinous process; Cr, cranial.
asj-2022-0445f2.jpg
Table 1.
Prevalence of subsidence in regard to the sagittal position of the implant position [18]
Ventral placement (%) Central placement (%) Dorsal placement (%)
Prevalence for subsidence 28.6 42.0 48.9
Subsidence pattern
 Lordotic 36.4 11.5 5.0
 Even 31.8 57.4 21.7
 Kyphotic 31.8 31.1 73.3
 Total 100.0 100.0 100.0

The bold type is the highest percentage within the group.

Table 2.
US Food and Drug Administration-approved artificial disc for 1-level cervical total disc replacement
Device Material Characteristics
Prestige ST Stainless steel Ball and trough design, dual-screw fixation
Bryan Polyurethane center, titanium endplates Bi-articulation device, shock-absorbing potential
ProDisc-C Cobalt chrome endplates, UHMWPE core Ball-and-socket, fixed center of rotation
Mobi-C Cobalt chrome endplates, UHMWPE core Ball in trough, translation in two planes. Also, 2-level approved
Secure-C Cobalt chrome endplates, UHMWPE core Ball in trough, translation enable
M6 Titanium endplates, polyurethane nucleus, UHMWPE annulus Shock- absorbing properties
PCM Cobalt chrome endplates, UHMWPE core Ball-and-socket
Prestige LP Titanium ceramic Ball in trough, translation enable. Also, 2-level approved
Simplify PEEK endplates, ceramic core Translation in two planes

From Bydon M et al. Neurosurg Clin N Am 2021;32:425-35 [57], with permission from Elsevier.

UHMWPE, ultrahigh molecular weight polyethylene; PEEK, polyetheretherketone.

References

1. Lees F, Turner JW. Natural history and prognosis of cervical spondylosis. Br Med J 1963 2:1607–10.
crossref pmid pmc
2. Wong JJ, Cote P, Quesnele JJ, Stern PJ, Mior SA. The course and prognostic factors of symptomatic cervical disc herniation with radiculopathy: a systematic review of the literature. Spine J 2014 14:1781–9.
crossref pmid
3. Sleijser-Koehorst ML, Coppieters MW, Heymans MW, Rooker S, Verhagen AP, Scholten-Peeters GG. Clinical course and prognostic models for the conservative management of cervical radiculopathy: a prospective cohort study. Eur Spine J 2018 27:2710–9.
crossref pmid pdf
4. Engquist M, Lofgren H, Oberg B, et al. A 5- to 8-year randomized study on the treatment of cervical radiculopathy: anterior cervical decompression and fusion plus physiotherapy versus physiotherapy alone. J Neurosurg Spine 2017 26:19–27.
crossref pmid
5. Lee CH, Hyun SJ, Kim MJ, et al. Comparative analysis of 3 different construct systems for single-level anterior cervical discectomy and fusion: stand-alone cage, iliac graft plus plate augmentation, and cage plus plating. J Spinal Disord Tech 2013 26:112–8.
pmid
6. Bible JE, Kang JD. Anterior cervical discectomy and fusion: surgical indications and outcomes. Semin Spine Surg 2016 28:80–3.
crossref
7. Yue WM, Brodner W, Highland TR. Long-term results after anterior cervical discectomy and fusion with allograft and plating: a 5- to 11-year radiologic and clinical follow-up study. Spine (Phila Pa 1976) 2005 30:2138–44.
pmid
8. Pirkle S, Kaskovich S, Cook DJ, Ho A, Shi LL, Lee MJ. Cages in ACDF are associated with a higher nonunion rate than allograft: a stratified comparative analysis of 6130 patients. Spine (Phila Pa 1976) 2019 44:384–8.
pmid
9. Chong E, Pelletier MH, Mobbs RJ, Walsh WR. The design evolution of interbody cages in anterior cervical discectomy and fusion: a systematic review. BMC Musculoskelet Disord 2015 16:99.
crossref pmid pmc pdf
10. Onyedimma C, Jallow O, Yolcu YU, et al. Comparison of outcomes between cage materials used for patients undergoing anterior cervical discectomy and fusion with standalone cages: a systematic review and meta-analysis. World Neurosurg 2022 158:e38–54.
crossref pmid
11. Brenke C, Kindling S, Scharf J, Schmieder K, Barth M. Short-term experience with a new absorbable composite cage (β-tricalcium phosphate-polylactic acid) in patients after stand-alone anterior cervical discectomy and fusion. Spine (Phila Pa 1976) 2013 38:E635–40.
crossref pmid
12. Kulkarni AG, Hee HT, Wong HK. Solis cage (PEEK) for anterior cervical fusion: preliminary radiological results with emphasis on fusion and subsidence. Spine J 2007 7:205–9.
crossref pmid
13. Olivares-Navarrete R, Gittens RA, Schneider JM, et al. Osteoblasts exhibit a more differentiated phenotype and increased bone morphogenetic protein production on titanium alloy substrates than on polyether-ether-ketone. Spine J 2012 12:265–72.
crossref pmid pmc
14. Han CM, Lee EJ, Kim HE, et al. The electron beam deposition of titanium on polyetheretherketone (PEEK) and the resulting enhanced biological properties. Biomaterials 2010 31:3465–70.
crossref pmid
15. Singh H, Kukowski NR, Lunati MP, et al. Porous 3D printed titanium cages in anterior cervical discectomy and fusion are associated with less subsidence, improved maintenance of segmental lordotic correction, and similar clinical outcomes as allograft. Global Spine J 2022 Sep 3 [Epub]. https://doi.org/10.1177/21925682221124527.
crossref
16. Barsa P, Suchomel P. Factors affecting sagittal malalignment due to cage subsidence in standalone cage assisted anterior cervical fusion. Eur Spine J 2007 16:1395–400.
crossref pmid pmc pdf
17. Jang HJ, Chin DK, Kim KH, Park JY. Does graft position affect subsidence after anterior cervical discectomy and fusion? Global Spine J 2022 12:668–76.
crossref pmid pmc pdf
18. Mende KC, Eicker SO, Weber F. Cage deviation in the subaxial cervical spine in relation to implant position in the sagittal plane. Neurosurg Rev 2018 41:267–74.
crossref pmid pdf
19. Yamagata T, Takami T, Uda T, et al. Outcomes of contemporary use of rectangular titanium stand-alone cages in anterior cervical discectomy and fusion: cage subsidence and cervical alignment. J Clin Neurosci 2012 19:1673–8.
crossref pmid
20. Truumees E, Demetropoulos CK, Yang KH, Herkowitz HN. Effects of disc height and distractive forces on graft compression in an anterior cervical discectomy model. Spine (Phila Pa 1976) 2002 27:2441–5.
crossref pmid
21. An HS, Evanich CJ, Nowicki BH, Haughton VM. Ideal thickness of Smith-Robinson graft for anterior cervical fusion: a cadaveric study with computed tomographic correlation. Spine (Phila Pa 1976) 1993 18:2043–7.
pmid
22. Lawless MH, Yoon EJ, Jasinski JM, et al. Impact of interspace distraction on fusion and clinical outcomes in anterior cervical discectomy and fusion: a longitudinal cohort study. Asian Spine J 2022 16:369–74.
crossref pmid pmc pdf
23. Cheung ZB, Gidumal S, White S, et al. Comparison of anterior cervical discectomy and fusion with a stand-alone interbody cage versus a conventional cage-plate technique: a systematic review and meta-analysis. Global Spine J 2019 9:446–55.
crossref pmid pmc pdf
24. Lee YS, Kim YB, Park SW. Risk factors for postoperative subsidence of single-level anterior cervical discectomy and fusion: the significance of the preoperative cervical alignment. Spine (Phila Pa 1976) 2014 39:1280–7.
pmid
25. Nunley PD, Jawahar A, Kerr EJ 3rd, Cavanaugh DA, Howard C, Brandao SM. Choice of plate may affect outcomes for single versus multilevel ACDF: results of a prospective randomized single-blind trial. Spine J 2009 9:121–7.
crossref pmid
26. Lim TH, Kwon H, Jeon CH, et al. Effect of endplate conditions and bone mineral density on the compressive strength of the graft-endplate interface in anterior cervical spine fusion. Spine (Phila Pa 1976) 2001 26:951–6.
crossref pmid
27. Pinter ZW, Monsef JB, Salmons HI, et al. Does preoperative bone mineral density impact fusion success in anterior cervical spine surgery?: a prospective cohort study. World Neurosurg 2022 164:e830–4.
crossref pmid
28. Cancienne JM, Werner BC, Hassanzadeh H, Singla A, Shen FH, Shimer AL. The association of perioperative glycemic control with deep postoperative infection after anterior cervical discectomy and fusion in patients with diabetes. World Neurosurg 2017 102:13–7.
crossref pmid
29. Arnold PM, Vaccaro AR, Sasso RC, et al. Two-year clinical and radiological outcomes in patients with diabetes undergoing single-level anterior cervical discectomy and fusion. Global Spine J 2021 11:458–64.
crossref pmid pmc pdf
30. Cerier E, Jain N, Lenobel S, Niedermeier SR, Stammen K, Yu E. Smoking is associated with 1-year suboptimal patient-reported outcomes after 2-level anterior cervical fusion. Clin Spine Surg 2019 32:175–8.
crossref pmid
31. Perez-Roman RJ, McCarthy D, Luther EM, et al. Effects of body mass index on perioperative outcomes in patients undergoing anterior cervical discectomy and fusion surgery. Neurospine 2021 18:79–86.
crossref pmid pmc pdf
32. Wang T, Ma L, Yang DL, et al. Factors predicting dysphagia after anterior cervical surgery: a multicenter retrospective study for 2 years of follow-up. Medicine (Baltimore) 2017 96:e7916.
pmid pmc
33. Khalooeifard R, Rahmani J, Tavanaei R, et al. The effect of vitamin D deficiency on outcomes of patients undergoing elective spinal fusion surgery: a systematic review and meta-analysis. Int J Spine Surg 2022 16:53–60.
crossref pmid pmc
34. Hofler RC, Swong K, Martin B, Wemhoff M, Jones GA. Risk of pseudoarthrosis after spinal fusion: analysis from the healthcare cost and utilization project. World Neurosurg 2018 120:e194–202.
crossref pmid
35. Fu MC, Gruskay JA, Samuel AM, et al. Outpatient anterior cervical discectomy and fusion is associated with fewer short-term complications in one- and two-level cases: a propensity-adjusted analysis. Spine (Phila Pa 1976) 2017 42:1044–9.
pmid
36. Lord EL, Cohen JR, Buser Z, et al. Trends, costs, and complications of anterior cervical discectomy and fusion with and without bone morphogenetic protein in the United States Medicare population. Global Spine J 2017 7:603–8.
crossref pmid pmc pdf
37. Mendenhall SK, Priddy BH, Mobasser JP, Potts EA. Safety and efficacy of low-dose rhBMP-2 use for anterior cervical fusion. Neurosurg Focus 2021 50:E2.
crossref
38. Varshneya K, Wadhwa H, Pendharkar AV, et al. Complications, costs, and quality outcomes of patients undergoing cervical deformity surgery with intraoperative BMP use. Spine (Phila Pa 1976) 2020 45:1553–8.
crossref pmid
39. Ahmad W, Bell J, Pierce KE, et al. P10: Bone morphogenetic protein usage decreases the risk of reoperations after anterior cervical discectomy and fusion: a five-year survivorship analysis. Spine J 2020 20:S152.
crossref
40. Jho HD. Microsurgical anterior cervical foraminotomy for radiculopathy: a new approach to cervical disc herniation. J Neurosurg 1996 84:155–60.
crossref pmid
41. Johnson JP, Filler AG, McBride DQ, Batzdorf U. Anterior cervical foraminotomy for unilateral radicular disease. Spine (Phila Pa 1976) 2000 25:905–9.
crossref pmid
42. Pakzaban P. Ultrasonic total uncinectomy: a novel technique for complete anterior decompression of cervical nerve roots. Neurosurgery 2014 10 Suppl 4:535–41.
pmid
43. Lee DH, Cho JH, Baik JM, et al. Does additional uncinate resection increase pseudarthrosis following anterior cervical discectomy and fusion? Spine (Phila Pa 1976) 2018 43:97–104.
crossref pmid
44. Safaee MM, Nichols NM, Yerneni K, Zhang Y, Riew KD, Tan LA. Safety and efficacy of direct nerve root decompression via anterior cervical discectomy and fusion with uncinectomy for cervical radiculopathy. J Spine Surg 2020 6:205–9.
crossref pmid pmc
45. Ferrete-Barroso AM, Gonzalez-Diaz R, Losada-Vinas JI. Anterior cervical arthrodesis using a vertebral body autograft. Rev Esp Cir Ortop Traumatol 2015 59:172–8.
crossref pmid
46. Guyer RD, Ohnmeiss DD. Intervertebral disc prostheses. Spine (Phila Pa 1976) 2003 28(15 Suppl): S15–23.
crossref pmid
47. Wahood W, Yolcu YU, Kerezoudis P, et al. Artificial discs in cervical disc replacement: a meta-analysis for comparison of long-term outcomes. World Neurosurg 2020 134:598–613.
crossref pmid
48. Kumar N, Liu ZJ, Poon WS, et al. ProDisc-C versus anterior cervical discectomy and fusion for the surgical treatment of symptomatic cervical disc disease: two-year outcomes of Asian prospective randomized controlled multicentre study. Eur Spine J 2022 31:1260–72.
pmid
49. Callanan G, Radcliff KE. Cervical total disc replacement: long-term outcomes. Neurosurg Clin N Am 2021 32:461–72.
pmid
50. Mummaneni PV, Burkus JK, Haid RW, Traynelis VC, Zdeblick TA. Clinical and radiographic analysis of cervical disc arthroplasty compared with allograft fusion: a randomized controlled clinical trial. J Neurosurg Spine 2007 6:198–209.
crossref pmid
51. Pimenta L, McAfee PC, Cappuccino A, Cunningham BW, Diaz R, Coutinho E. Superiority of multilevel cervical arthroplasty outcomes versus single-level outcomes: 229 consecutive PCM prostheses. Spine (Phila Pa 1976) 2007 32:1337–44.
pmid
52. Steinmetz MP, Berven SH, Benzel EC. Benzel’s spine surgery: techniques, complication avoidance, and management. 5th ed. Philadelphia (PA): Elsevier Health Sciences; 2021.

53. Patwardhan AG, Havey RM. Biomechanics of cervical disc arthroplasty devices. Neurosurg Clin N Am 2021 32:493–504.
crossref pmid
54. Nunley P, Schouwen KF, Stone M. Cervical total disc replacement: indications and technique. Neurosurg Clin N Am 2021 32:419–24.
crossref pmid
55. Gornet MF, Burkus JK, Shaffrey ME, Nian H, Harrell FE Jr. Cervical disc arthroplasty with Prestige LP disc versus anterior cervical discectomy and fusion: seven-year outcomes. Int J Spine Surg 2016 10:24.
crossref pmid pmc
56. Mummaneni PV, Robinson JC, Haid RW Jr. Cervical arthroplasty with the PRESTIGE LP cervical disc. Neurosurgery 2007 60(4 Suppl 2): 310–5.
crossref pmid
57. Bydon M, Michalopoulos GD, Alvi MA, Goyal A, Abode-Iyamah K. Cervical total disc replacement: Food and Drug Administration-approved devices. Neurosurg Clin N Am 2021 32:425–35.
pmid
58. Yuan W, Zhang H, Zhou X, Wu W, Zhu Y. The influence of artificial cervical disc prosthesis height on the cervical biomechanics: a finite element study. World Neurosurg 2018 113:e490–8.
crossref pmid
59. Shin JJ, Kim KR, Son DW, et al. Cervical disc arthroplasty: what we know in 2020 and a literature review. J Orthop Surg (Hong Kong) 2021 29(1_suppl): 23094990211006934.
crossref pmid pdf
60. Qureshi SA, McAnany S, Goz V, Koehler SM, Hecht AC. Cost-effectiveness analysis: comparing single-level cervical disc replacement and single-level anterior cervical discectomy and fusion: clinical article. J Neurosurg Spine 2013 19:546–54.
pmid
61. Patwardhan AG, Havey RM. Biomechanics of cervical disc arthroplasty: a review of concepts and current technology. Int J Spine Surg 2020 14(s2): S14–28.
crossref pmid pmc
62. Kouyoumdjian P, Bronsard N, Vital JM, Gille O. Centering of cervical disc replacements: usefulness of intraoperative anteroposterior fluoroscopic guidance to center cervical disc replacements: study on 20 discocerv (scient’x prosthesis). Spine (Phila Pa 1976) 2009 34:1572–7.
pmid
63. Voronov LI, Havey RM, Tsitsopoulos PP, et al. Does resection of the posterior longitudinal ligament affect the stability of cervical disc arthroplasty? Int J Spine Surg 2018 12:285–94.
crossref pmid pmc
64. Kim SW, Paik SH, Castro PA, et al. Analysis of factors that may influence range of motion after cervical disc arthroplasty. Spine J 2010 10:683–8.
crossref pmid
65. Tu TH, Kuo CH, Huang WC, Fay LY, Cheng H, Wu JC. Effects of smoking on cervical disc arthroplasty. J Neurosurg Spine 2019 30:168–74.
crossref pmid
66. Zeidan M, Goz V, Lakomkin N, Spina N, Brodke DS, Spiker WR. Predictors of readmission and prolonged length of stay after cervical disc arthroplasty. Spine (Phila Pa 1976) 2021 46:487–91.
crossref pmid
67. Steinberger J, Qureshi S. Cervical disc replacement. Neurosurg Clin N Am 2020 31:73–9.
crossref pmid
68. Tu TH, Wu JC, Huang WC, Wu CL, Ko CC, Cheng H. The effects of carpentry on heterotopic ossification and mobility in cervical arthroplasty: determination by computed tomography with a minimum 2-year follow-up: clinical article. J Neurosurg Spine 2012 16:601–9.
pmid
69. Mehren C, Suchomel P, Grochulla F, et al. Heterotopic ossification in total cervical artificial disc replacement. Spine (Phila Pa 1976) 2006 31:2802–6.
crossref pmid
70. Sharma JK, Varma KK, Mallepally AR, et al. Two-level anterior cervical discectomy and fusion versus hybrid total disc replacement for bilevel pathology with cervical radiculopathy/myelopathy: a comparative study with a minimum 2-year follow-up in an Indian population. Asian Spine J 2022 16:493–501.
crossref pmid pmc pdf
71. Jia Z, Mo Z, Ding F, He Q, Fan Y, Ruan D. Hybrid surgery for multilevel cervical degenerative disc diseases: a systematic review of biomechanical and clinical evidence. Eur Spine J 2014 23:1619–32.
crossref pmid pdf
72. Laratta JL, Shillingford JN, Saifi C, Riew KD. Cervical disc arthroplasty: a comprehensive review of single-level, multilevel, and hybrid procedures. Global Spine J 2018 8:78–83.
crossref pmid pmc pdf
73. Zavras AG, Dandu N, Nolte MT, et al. Segmental range of motion after cervical total disc arthroplasty at long-term follow-up: a systematic review and meta-analysis. J Neurosurg Spine 2022 Apr 22 [Epub]. https://doi.org/10.3171/2022.2.SPINE2281.
crossref
74. Burkus JK, Traynelis VC, Haid RW Jr, Mummaneni PV. Clinical and radiographic analysis of an artificial cervical disc: 7-year follow-up from the Prestige prospective randomized controlled clinical trial: clinical article. J Neurosurg Spine 2014 21:516–28.
pmid
75. Lubelski D, Healy AT, Silverstein MP, et al. Reoperation rates after anterior cervical discectomy and fusion versus posterior cervical foraminotomy: a propensity-matched analysis. Spine J 2015 15:1277–83.
crossref pmid
76. Selvanathan SK, Beagrie C, Thomson S, et al. Anterior cervical discectomy and fusion versus posterior cervical foraminotomy in the treatment of brachialgia: the Leeds spinal unit experience (2008-2013). Acta Neurochir (Wien) 2015 157:1595–600.
crossref pmid pdf
77. Fountas KN, Kapsalaki EZ, Nikolakakos LG, et al. Anterior cervical discectomy and fusion associated complications. Spine (Phila Pa 1976) 2007 32:2310–7.
crossref pmid
78. Albert TJ, Vacarro A. Postlaminectomy kyphosis. Spine (Phila Pa 1976) 1998 23:2738–45.
crossref pmid
79. Mikawa Y, Shikata J, Yamamuro T. Spinal deformity and instability after multilevel cervical laminectomy. Spine (Phila Pa 1976) 1987 12:6–11.
crossref pmid
80. Ruetten S, Komp M, Merk H, Godolias G. Fullendoscopic cervical posterior foraminotomy for the operation of lateral disc herniations using 5.9-mm endoscopes: a prospective, randomized, controlled study. Spine (Phila Pa 1976) 2008 33:940–8.
pmid
81. Rossi V, Adamson T. Cervical spine surgery: arthroplasty versus fusion versus posterior foraminotomy. Neurosurg Clin N Am 2021 32:483–92.
pmid
82. Dodwad SJ, Dodwad SN, Prasarn ML, Savage JW, Patel AA, Hsu WK. Posterior cervical foraminotomy: indications, technique, and outcomes. Clin Spine Surg 2016 29:177–85.
pmid
83. Zeidman SM, Ducker TB. Posterior cervical laminoforaminotomy for radiculopathy: review of 172 cases. Neurosurgery 1993 33:356–62.
crossref pmid
84. Skovrlj B, Gologorsky Y, Haque R, Fessler RG, Qureshi SA. Complications, outcomes, and need for fusion after minimally invasive posterior cervical foraminotomy and microdiscectomy. Spine J 2014 14:2405–11.
crossref pmid
85. Church EW, Halpern CH, Faught RW, et al. Cervical laminoforaminotomy for radiculopathy: symptomatic and functional outcomes in a large cohort with long-term follow-up. Surg Neurol Int 2014 5(Suppl 15): S536–43.
crossref pmid pmc
86. Witzmann A, Hejazi N, Krasznai L. Posterior cervical foraminotomy: a follow-up study of 67 surgically treated patients with compressive radiculopathy. Neurosurg Rev 2000 23:213–7.
crossref pmid pdf
87. Holly LT, Moftakhar P, Khoo LT, Wang JC, Shamie N. Minimally invasive 2-level posterior cervical foraminotomy: preliminary clinical results. J Spinal Disord Tech 2007 20:20–4.
pmid
88. Zdeblick TA, Zou D, Warden KE, McCabe R, Kunz D, Vanderby R. Cervical stability after foraminotomy: a biomechanical in vitro analysis. J Bone Joint Surg Am 1992 74:22–7.
crossref pmid
89. Scoville WB. Cervical spondylosis treated by bilateral facetectomy and laminectomy. J Neurosurg 1961 18:423–8.
crossref pmid
90. Barakat M, Hussein Y. Anatomical study of the cervical nerve roots for posterior foraminotomy: cadaveric study. Eur Spine J 2012 21:1383–8.
crossref pmid pmc pdf
91. Hwang JC, Bae HG, Cho SW, Cho SJ, Park HK, Chang JC. Morphometric study of the nerve roots around the lateral mass for posterior foraminotomy. J Korean Neurosurg Soc 2010 47:358–64.
crossref pmid pmc
92. Baba H, Chen Q, Uchida K, Imura S, Morikawa S, Tomita K. Laminoplasty with foraminotomy for coexisting cervical myelopathy and unilateral radiculopathy: a preliminary report. Spine (Phila Pa 1976) 1996 21:196–202.
pmid
93. Chen BH, Natarajan RN, An HS, Andersson GB. Comparison of biomechanical response to surgical procedures used for cervical radiculopathy: posterior keyhole foraminotomy versus anterior foraminotomy and discectomy versus anterior discectomy with fusion. J Spinal Disord 2001 14:17–20.
crossref pmid
94. Raynor RB, Pugh J, Shapiro I. Cervical facetectomy and its effect on spine strength. J Neurosurg 1985 63:278–82.
crossref pmid
95. Rodrigues MA, Hanel RA, Prevedello DM, Antoniuk A, Araujo JC. Posterior approach for soft cervical disc herniation: a neglected technique? Surg Neurol 2001 55:17–22.
crossref pmid
96. Tanaka N, Fujimoto Y, An HS, Ikuta Y, Yasuda M. The anatomic relation among the nerve roots, intervertebral foramina, and intervertebral discs of the cervical spine. Spine (Phila Pa 1976) 2000 25:286–91.
crossref pmid
97. Coric D, Adamson T. Minimally invasive cervical microendoscopic laminoforaminotomy. Neurosurg Focus 2008 25:E2.
crossref
98. Grieve JP, Kitchen ND, Moore AJ, Marsh HT. Results of posterior cervical foraminotomy for treatment of cervical spondylitic radiculopathy. Br J Neurosurg 2000 14:40–3.
crossref pmid
99. Hilton DL Jr. Minimally invasive tubular access for posterior cervical foraminotomy with three-dimensional microscopic visualization and localization with anterior/posterior imaging. Spine J 2007 7:154–8.
crossref pmid
100. Burke TG, Caputy A. Microendoscopic posterior cervical foraminotomy: a cadaveric model and clinical application for cervical radiculopathy. J Neurosurg 2000 93(1 Suppl): 126–9.
crossref pmid
101. Laing RJ, Ng I, Seeley HM, Hutchinson PJ. Prospective study of clinical and radiological outcome after anterior cervical discectomy. Br J Neurosurg 2001 15:319–23.
crossref pmid
102. Woertgen C, Rothoerl RD, Henkel J, Brawanski A. Long term outcome after cervical foraminotomy. J Clin Neurosci 2000 7:312–5.
crossref pmid
103. Bhatia S, Brooks NP. Posterior endoscopic cervical foraminotomy. Neurosurg Clin N Am 2020 31:9–16.
crossref pmid
104. Kabil MS, Abdel-ghany W. Microendoscopic anterior cervical foraminotomy: a preliminary series of 76 cases. Egypt J Neurosurg 2020 35:12.
crossref pdf
105. Sasai K, Umeda M, Saito T, Ohnari H, Wakabayashi E, Iida H. Microsurgical posterior foraminotomy with laminoplasty for cervical spondylotic radiculomyelopathy including cervical spondylotic amyotrophy. J Neurosurg Spine 2006 5:126–32.
crossref pmid
106. Lee DH, Cho JH, Hwang CJ, Lee CS, Kim C, Ha JK. Multilevel posterior foraminotomy with laminoplasty versus laminoplasty alone for cervical spondylotic myelopathy with radiculopathy: a comparative study. Spine J 2018 18:414–21.
crossref pmid
107. Liu G, Buchowski JM, Bunmaprasert T, Yeom JS, Shen H, Riew KD. Revision surgery following cervical laminoplasty: etiology and treatment strategies. Spine (Phila Pa 1976) 2009 34:2760–8.
pmid
108. Komagata M, Nishiyama M, Endo K, Ikegami H, Tanaka S, Imakiire A. Prophylaxis of C5 palsy after cervical expansive laminoplasty by bilateral partial foraminotomy. Spine J 2004 4:650–5.
crossref pmid
109. Heo J, Chang JC, Park HK. Long-term outcome of posterior cervical inclinatory foraminotomy. J Korean Neurosurg Soc 2016 59:374–8.
crossref pmid pmc
110. Bielecki M, Kunert P, Balasa A, Kujawski S, Marchel A. Long-term clinical results with radiological correlations after posterior foraminotomy for unilateral cervical discopathy. World Neurosurg 2022 158:e799–809.
crossref pmid
111. MacDowall A, Heary RF, Holy M, Lindhagen L, Olerud C. Posterior foraminotomy versus anterior decompression and fusion in patients with cervical degenerative disc disease with radiculopathy: up to 5 years of outcome from the national Swedish Spine Register. J Neurosurg Spine 2019 32:344–52.
crossref
112. Findlay C, Ayis S, Demetriades AK. Total disc replacement versus anterior cervical discectomy and fusion: a systematic review with meta-analysis of data from a total of 3160 patients across 14 randomized controlled trials with both short- and medium- to long-term outcomes. Bone Joint J 2018 100-B:991–1001.
pmid
113. Zhong ZM, Zhu SY, Zhuang JS, Wu Q, Chen JT. Reoperation after cervical disc arthroplasty versus anterior cervical discectomy and fusion: a meta-analysis. Clin Orthop Relat Res 2016 474:1307–16.
crossref pmid pmc pdf
114. Janssen ME, Zigler JE, Spivak JM, Delamarter RB, Darden BV 2nd, Kopjar B. ProDisc-C total disc replacement versus anterior cervical discectomy and fusion for single-level symptomatic cervical disc disease: seven-year follow-up of the prospective randomized U.S. Food and Drug Administration investigational device exemption study. J Bone Joint Surg Am 2015 97:1738–47.
pmid
115. Koreckij TD, Gandhi SD, Park DK. Cervical disk arthroplasty. J Am Acad Orthop Surg 2019 27:e96–104.
crossref pmid
116. Zhu Y, Tian Z, Zhu B, Zhang W, Li Y, Zhu Q. Bryan cervical disc arthroplasty versus anterior cervical discectomy and fusion for treatment of cervical disc diseases: a meta-analysis of prospective, randomized controlled trials. Spine (Phila Pa 1976) 2016 41:E733–41.
pmid
117. Zhu Y, Zhang B, Liu H, Wu Y, Zhu Q. Cervical disc arthroplasty versus anterior cervical discectomy and fusion for incidence of symptomatic adjacent segment disease: a meta-analysis of prospective randomized controlled trials. Spine (Phila Pa 1976) 2016 41:1493–502.
pmid
118. Verma K, Gandhi SD, Maltenfort M, et al. Rate of adjacent segment disease in cervical disc arthroplasty versus single-level fusion: meta-analysis of prospective studies. Spine (Phila Pa 1976) 2013 38:2253–7.
pmid
119. Xie L, Liu M, Ding F, Li P, Ma D. Cervical disc arthroplasty (CDA) versus anterior cervical discectomy and fusion (ACDF) in symptomatic cervical degenerative disc diseases (CDDDs): an updated meta-analysis of prospective randomized controlled trials (RCTs). Springerplus 2016 5:1188.
crossref pmid pmc pdf
120. Vaccaro A, Beutler W, Peppelman W, et al. Clinical outcomes with selectively constrained SECURE-C cervical disc arthroplasty: two-year results from a prospective, randomized, controlled, multicenter investigational device exemption study. Spine (Phila Pa 1976) 2013 38:2227–39.
pmid
121. Sasso RC, Anderson PA, Riew KD, Heller JG. Results of cervical arthroplasty compared with anterior discectomy and fusion: four-year clinical outcomes in a prospective, randomized controlled trial. J Bone Joint Surg Am 2011 93:1684–92.
crossref pmid
122. Hisey MS, Zigler JE, Jackson R, et al. Prospective, randomized comparison of one-level Mobi-C cervical total disc replacement vs. anterior cervical discectomy and fusion: results at 5-year follow-up. Int J Spine Surg 2016 10:10.
crossref pmid pmc
123. Jackson RJ, Davis RJ, Hoffman GA, et al. Subsequent surgery rates after cervical total disc replacement using a Mobi-C Cervical Disc Prosthesis versus anterior cervical discectomy and fusion: a prospective randomized clinical trial with 5-year follow-up. J Neurosurg Spine 2016 24:734–45.
crossref pmid
124. Radcliff K, Coric D, Albert T. Five-year clinical results of cervical total disc replacement compared with anterior discectomy and fusion for treatment of 2-level symptomatic degenerative disc disease: a prospective, randomized, controlled, multicenter investigational device exemption clinical trial. J Neurosurg Spine 2016 25:213–24.
crossref pmid
125. Phillips FM, Geisler FH, Gilder KM, Reah C, Howell KM, McAfee PC. Long-term outcomes of the US FDA IDE prospective, randomized controlled clinical trial comparing PCM cervical disc arthroplasty with anterior cervical discectomy and fusion. Spine (Phila Pa 1976) 2015 40:674–83.
crossref pmid
126. Dunn C, Moore J, Sahai N, et al. Minimally invasive posterior cervical foraminotomy with tubes to prevent undesired fusion: a long-term follow-up study. J Neurosurg Spine 2018 29:358–64.
crossref pmid
127. Rand JA, Trousdale RT, Ilstrup DM, Harmsen WS. Factors affecting the durability of primary total knee prostheses. J Bone Joint Surg Am 2003 85:259–65.
crossref pmid
128. Joaquim AF, Lee NJ, Riew KD. Revision surgeries at the index level after cervical disc arthroplasty: a systematic review. Neurospine 2021 18:34–44.
crossref pmid pmc pdf
129. Wang TY, Lubelski D, Abdullah KG, Steinmetz MP, Benzel EC, Mroz TE. Rates of anterior cervical discectomy and fusion after initial posterior cervical foraminotomy. Spine J 2015 15:971–6.
crossref pmid
130. Buchowski JM, Sekhon LH, Yoon DH, et al. Adverse events of cervical arthroplasty. Tech Orthop 2010 25:138–44.
crossref


ABOUT
ARTICLE CATEGORY

Browse all articles >

BROWSE ARTICLES
EDITORIAL POLICY
FOR CONTRIBUTORS
Editorial Office
Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine
88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Korea
Tel: +82-2-3010-3530    Fax: +82-2-3010-8555    E-mail: spinecjh@gmail.com                

Copyright © 2023 by Korean Society of Spine Surgery.

Developed in M2PI

Close layer
prev next