Two-level or more-level anterior cervical discectomy and fusion

J.Sales-Llopis

Neurosurgery Department, Alicante University General Hospital, Spain.

Two-level or more-level anterior cervical discectomy and fusion (ACDF) is a surgical procedure designed to address cervical spine conditions involving damage or degeneration of two or more adjacent cervical discs. This procedure, akin to standard ACDF, entails the removal of multiple discs and the fusion of adjacent vertebrae across two or more levels. Indications for this surgery include cervical disc herniation affecting multiple levels, severe degenerative disc disease across two or more cervical levels, spinal stenosis affecting multiple cervical levels, or spinal instability due to disc degeneration or injury in multiple segments. The surgical process involves general anesthesia, an incision in the neck, disc removal, bone grafting, and the potential use of implants for stability. Recovery typically necessitates a cervical collar or brace and may involve physical therapy, with full recovery taking weeks to months. Risks and complications, such as infection or graft problems, exist, but successful outcomes can alleviate symptoms and restore cervical spine stability. Alternative procedures, like cervical disc replacement, may be considered based on individual patient needs. Studies have explored the effectiveness of multi-level ACDF and related surgical approaches, revealing improved clinical outcomes and alignment parameters. These findings support multi-level ACDF as a viable treatment option for specific cervical spine conditions.

A two-level or more-level anterior cervical discectomy and fusion (ACDF) is a surgical procedure performed on the cervical spine (neck) to treat conditions involving two or more adjacent cervical discs that have become damaged or degenerated. This procedure is similar to the standard ACDF but involves the removal of multiple discs and the fusion of adjacent vertebrae at two or more levels. Here are some key points about this surgical procedure:

Indications: A two-level or more-level ACDF is typically recommended for conditions such as:

Cervical disc herniation affects multiple levels. Severe degenerative disc disease involving two or more levels of the cervical spine. Spinal stenosis that affects multiple levels of the cervical spine. The presence of spinal instability due to disc degeneration or injury in multiple segments. Procedure:

Anesthesia: The surgery is performed under general anesthesia to ensure that the patient is unconscious and pain-free during the procedure. Incision: The surgeon makes an incision in the front of the neck, usually on the left or right side, to access the cervical spine. Disc Removal: The surgeon removes the damaged or degenerated cervical discs at two or more levels to relieve pressure on the spinal cord or nerve roots. Bone Grafting: To stabilize the spine, bone graft material is inserted between the adjacent vertebrae where the discs were removed. The graft can be sourced from the patient's own bone (autograft), a donor (allograft), or synthetic materials. The goal is for the graft to promote fusion of the vertebrae over time. Implants: In some cases, the surgeon may use metal plates, screws, or other hardware to maintain proper alignment and stability during the fusion process. Closure: After ensuring proper alignment and stabilization, the surgeon closes the incision with sutures or staples. Recovery: The recovery process following a two-level or more-level ACDF is similar to that of a single-level procedure. Patients may need to wear a cervical collar or brace for a period to support healing and limit neck motion. Physical therapy may be recommended to aid in rehabilitation. Recovery times can vary, but patients should expect several weeks to months for full recovery.

Risks and Complications: As with any surgical procedure, there are potential risks and complications associated with multi-level ACDF, including infection, bleeding, nerve injury, graft or hardware problems, and the possibility of continued or new symptoms.

Outcomes: The success of the surgery depends on multiple factors, including the patient's overall health, adherence to post-operative care instructions, and the extent of fusion achieved. Multi-level ACDF can provide relief from symptoms and restore stability to the cervical spine.

Alternative Procedures: In some cases, other surgical techniques, such as cervical disc replacement (arthroplasty), may be considered as an alternative to multi-level ACDF, particularly for preserving neck motion.

It is crucial for individuals considering a two-level or more-level ACDF to have a thorough discussion with their healthcare provider and surgeon to fully understand the benefits, risks, and potential outcomes of the procedure. The decision to undergo surgery should be based on an individual's specific condition and needs, with careful consideration of all available treatment options.

The study conducted by Byvaltsev et al. aimed to evaluate the effectiveness of a specific surgical approach for treating patients with two-level cervical degenerative disc disease. This approach was based on an algorithm that took into account preoperative clinical and imaging parameters to determine the most appropriate treatment for each patient.

The study included a total of 244 patients with two-level cervical degenerative disc disease, and these patients were divided into two groups:

Prospective Group (Group I, n = 126): This group consisted of patients who were treated using the algorithmic approach. The algorithm helped decide whether each patient should undergo a two-level cervical disc arthroplasty, Anterior Cervical Discectomy and Fusion (ACDF), or a hybrid technique that combines elements of both procedures.

Control Group (Group II, n = 118): This group included patients who had undergone a similar two-level procedure in the past, specifically between 2005 and 2015. Their treatment approach did not involve the algorithm but instead followed conventional methods.

The researchers collected various clinical and outcome measures from both groups, including:

Visual Analogue Scale (VAS) scores for neck pain and upper limb pain: These scores assessed the level of pain experienced by patients.

Neck Disability Index (NDI) score: This score evaluated the impact of neck-related disability on patients' daily lives.

SF-36 score: This score measured health-related quality of life.

Macnab scale: This scale assessed patients' satisfaction with the surgery's outcome.

Nurick scale: This scale evaluated the outcome of the surgery in terms of neurological improvement.

Additionally, the study identified and compared perioperative complications between the two groups.

The results of the study showed that, at a minimum of 2 years of follow-up, Group I (the prospective group treated using the algorithmic approach) had significantly better clinical outcomes compared to Group II (the control group). Specifically, Group I had lower VAS scores for neck and upper limb pain, a lower NDI score, higher SF-36 scores, greater satisfaction with the surgery based on the Macnab scale, and better surgical outcomes according to the Nurick scale. Furthermore, the complication rate in Group I was significantly lower than that in Group II.

In summary, Byvaltsev et al. demonstrated that using an algorithmic approach to determine the appropriate surgical treatment for patients with two-level cervical degenerative disc disease resulted in improved functional outcomes and a reduced rate of complications compared to conventional surgical methods. This suggests that the algorithm-based approach is a promising strategy for optimizing the surgical management of such patients. ¹⁾.

Huang et al. aimed to compare different surgical approaches used for treating patients with cervical spine issues, specifically focusing on the differences between one-level cervical disc arthroplasty (CDA) and two-level anterior cervical discectomy and fusion (ACDF). Here's a breakdown of the study's design and findings:

Study Design:

Patients: The study involved patients who underwent surgery between June 2012 and July 2020 for cervical spine problems. Surgical Constructs: The researchers divided the patients into three groups, each representing a different surgical construct: Type Ⅰa: This group had a sequence of surgeries as CDA-ACDF-ACDF. Type Ⅰb: This group had a sequence of surgeries as ACDF-CDA-ACDF. Type Ⅰc: This group had a sequence of surgeries as ACDF-ACDF-CDA. Measurements and Outcomes:

Clinical Outcomes: The study assessed clinical outcomes using measures such as the Japanese Orthopedic Association score, Neck Disability Index, and Visual Analog Scale scores, which help evaluate pain and disability. Range of Motion (ROM): The researchers measured the range of motion of the total cervical spine and assessed differences between the three surgical construct groups. Fusion Rates: Fusion rates were examined to determine the success of the surgical constructs. Specifically, the study looked at fusion rates in superior ACDF segments compared to inferior ACDF segments at 6 and 12 months post-surgery. Key Findings:

Clinical Improvement: All three groups (Type Ⅰa, Type Ⅰb, and Type Ⅰc) showed significant clinical improvement in terms of pain and disability after surgery. Range of Motion (ROM): The Type Ⅰc group, which had ACDF surgeries on both ends of the construct, experienced a significant decrease in the range of motion of the total cervical spine compared to the other two groups (Type Ⅰa and Type Ⅰb). Fusion Rates: The study found that the fusion rates in superior ACDF segments were significantly higher at both 6 and 12 months post-surgery when compared to the fusion rates in the inferior ACDF segments. Clinical Outcomes Similar: Interestingly, despite the differences in surgical constructs, the study found that clinical outcomes were similar among the three groups. This suggests that the choice of surgical construct did not significantly impact patients' clinical improvement in terms of pain and disability.

In summary, this study compared different surgical constructs involving CDA and ACDF for cervical spine conditions. While there were variations in the range of motion and fusion rates among the constructs, clinical outcomes were similar across the groups. These findings can help guide surgeons in selecting the most appropriate surgical approach based on specific patient needs and conditions ²⁾.

Bakare et al. aimed to compare the outcomes of two surgical approaches for treating 2-level cervical degenerative disc disease: cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) with anterior plate fixation. Here's an explanation of the study's methods and findings:

Study Methods:

Patient Cohort: The study included 82 patients who underwent surgery for 2-level cervical degenerative disc disease between 2014 and 2019.

Surgical Procedures: Patients were divided into two cohorts based on the surgical procedure they received: 2-level CDA or 2-level ACDF with anterior plate fixation.

Cervical Alignment Parameters: The study focused on assessing cervical alignment parameters, which include measurements related to the curvature and alignment of the cervical spine.

Key Findings:

Cervical Lordosis (CL) Improvement: Both the CDA and ACDF groups experienced significant improvements in cervical lordosis (CL) following surgery.

Focal Lordosis (FL) Gain: Initially, the CDA group showed a significantly greater gain in focal lordosis (FL) compared to the ACDF group. However, when considering other preoperative variables in a multivariate analysis, this difference was no longer significant.

Cervical Sagittal Vertical Axis (cSVA): The CDA group had significant improvements in cSVA at 3 and 12 months post-surgery, but these improvements were not superior to those seen in the ACDF group.

Factors Affecting Outcomes: Several factors were identified that influenced the outcomes:

Male patients in the CDA group achieved greater CL gain at 12 months.

Patients with a body mass index (BMI) greater than 25 kg/m2 in the CDA group achieved greater FL gain at 12 months.

Patients in the CDA group with symptom duration greater than 12 months achieved greater FL gain at both 3 and 12 months.

Patients in the CDA group with a high baseline T1 slope or cSVA achieved greater cSVA reduction at 12 months.

Clinical Outcomes: Clinical outcomes, including the Neck Disability Index, arm pain, and 12-Item Short-Form Mental Component Scores, were comparable between the CDA and ACDF groups.

Heterotopic Ossification: The study found that heterotopic ossification (abnormal bone growth) did not significantly affect patient outcomes or cervical alignment in either group.

Conclusions: The study's findings suggest that both ACDF and CDA are suitable treatment options for 2-level degenerative disc disease in carefully selected patients. Both procedures resulted in similar postoperative improvements in cervical alignment. Factors such as gender, BMI, symptom duration, and baseline T1 slope or cSVA may influence the outcomes in CDA patients. The study indicates that clinicians can consider these factors when deciding between ACDF and CDA for their patients. Additionally, the study highlights that clinical outcomes were comparable between the two surgical approaches, suggesting that patient well-being and symptom relief can be achieved with either procedure. ³⁾

The study conducted by Xiong et al. aimed to compare the clinical and radiological outcomes of two surgical approaches for treating symptomatic contiguous two-level cervical degenerative disc disease (CDDD). The two approaches being compared were a hybrid surgery (HS) involving the use of Mobi-C and ROI-C artificial disc replacements and anterior cervical discectomy and fusion (ACDF) using the ROI-C device. Here's an explanation of the study and its findings:

Study Overview:

Patient Cohort: The study included a total of 91 patients who had symptomatic contiguous two-level CDDD. Surgical Groups: The patients were divided into two groups: the HS group (48 patients) and the ACDF group (43 patients). Follow-Up: Clinical and radiological outcomes were evaluated for more than two years after the surgeries. Key Findings:

Clinical Outcomes: Both the HS and ACDF groups showed significant improvements in clinical outcomes, including scores on the Visual Analog Scale (VAS) for pain, Japanese Orthopedic Association (JOA), and Neck Disability Index (NDI). These improvements were statistically significant (p < 0.05). No Significant Differences Between Groups: The study found that there were no statistically significant differences in clinical outcomes between the HS and ACDF groups (p > 0.05). This indicates that both surgical approaches resulted in similar improvements in patients' pain levels and neck-related disability. Range of Motion (ROM): The study observed that the global range of motion (ROM) in the HS group was significantly larger than that in the ACDF group (p < 0.05). This suggests that the HS approach allowed for greater neck mobility. Local Lordosis Improvement: Both surgical groups experienced significant improvements in local lordosis, which is the curvature of the spine in the cervical region (p < 0.05). Bone Resorption and Heterotopic Ossification (HO): After the surgeries, the study noted the presence of bone resorption and heterotopic ossification (abnormal bone growth) in some patients. These are common findings in cervical spine surgeries and were not specific to either the HS or ACDF group. Benefits of HS: The study's results indicated that HS might be a viable alternative for treating contiguous two-level CDDD in selected patients. HS offered the advantage of providing greater global range of motion (ROM) in the cervical spine and also greater ROM specifically at the Mobi-C index level. Need for Further Studies: While the study provided valuable insights, the authors emphasized the need for further research and long-term follow-up to better understand the outcomes of these surgical approaches. Conclusions: In summary, the study by Xiong et al. compared the outcomes of hybrid surgery (HS) and anterior cervical discectomy and fusion (ACDF) for treating contiguous two-level cervical degenerative disc disease. Both approaches led to significant clinical improvements in pain and disability scores. HS offered the advantage of greater cervical range of motion, especially at the artificial disc replacement level. However, further studies and longer-term follow-up are required to fully assess the effectiveness and long-term outcomes of these surgical techniques. ⁴⁾

Four-year results from a study by Davis et al. continue to support TDR as a safe, effective, and statistically superior alternative to ACDF for the treatment of degenerative disc disease at 2 contiguous cervical levels. Clinical trial registration no.: NCT00389597 ( clinicaltrials.gov) ⁵⁾.

The studies discussed highlight important findings and considerations in the surgical management of cervical spine conditions involving degenerative disc disease. These conditions can cause significant pain, disability, and neurological symptoms, making effective surgical interventions crucial. Let's discuss the key takeaways from these studies in the context of their abstracts:

Two-Level or More-Level Anterior Cervical Discectomy and Fusion (ACDF):

Two-level or more-level ACDF is a surgical procedure used to address cervical spine conditions affecting two or more adjacent cervical discs. The procedure involves disc removal, bone grafting, and potential implant use for stability. Indications include multiple disc herniations, severe degenerative disc disease, spinal stenosis, and instability. Recovery involves wearing a cervical collar or brace and may require physical therapy. While effective, the procedure carries potential risks and complications. Alternative procedures like cervical disc replacement may be considered. Studies support multi-level ACDF as a viable option for specific cervical spine conditions. Algorithmic Approach for Two-Level Cervical Degenerative Disc Disease:

An algorithmic approach was used to decide treatment (TDR, ACDF, or hybrid) for patients with two-level cervical degenerative disc disease. Patients treated with the algorithm had better clinical outcomes and lower complication rates compared to conventional methods. Clinical parameters, including pain scores, disability index, quality of life, and patient satisfaction, improved significantly in the algorithm group. The study suggests that using algorithms to guide surgical decisions can lead to better outcomes and fewer complications. Comparison of Cervical Disc Arthroplasty (CDA) and Anterior Cervical Discectomy and Fusion (ACDF):

The study compared one-level CDA with two-level ACDF and evaluated clinical outcomes, range of motion, and fusion rates. All groups showed significant clinical improvement, regardless of surgical construct. The group with two-level ACDF at both ends of the construct experienced decreased total cervical spine range of motion. Fusion rates were higher in superior ACDF segments than in inferior segments. Clinical outcomes were similar across the three surgical construct groups, suggesting that patient well-being and symptom relief can be achieved with different approaches. Hybrid Surgery vs. ACDF for Contiguous Two-Level Cervical Degenerative Disc Disease:

The study compared hybrid surgery (HS) using Mobi-C and ROI-C with ACDF using ROI-C for two-level cervical degenerative disc disease. Both groups showed significant clinical improvements in pain and disability scores. The HS group had greater global range of motion compared to the ACDF group. Clinical outcomes were similar between the two groups. The study highlighted the potential benefits of HS in terms of cervical range of motion. Further research and long-term follow-up are needed to better understand outcomes. Four-Year Results Supporting Total Disc Replacement (TDR):

Four-year results from a study continue to support TDR as a safe, effective, and superior alternative to ACDF for treating degenerative disc disease at two contiguous cervical levels. The findings emphasize the long-term benefits and superiority of TDR over ACDF in specific cases. In summary, these studies underscore the importance of tailored surgical approaches for cervical spine conditions. While each procedure has its advantages and considerations, the choice of surgical intervention should be based on individual patient needs, clinical assessments, and careful consideration of the available options. Additionally, ongoing research and long-term follow-up are essential to further refine and validate these surgical techniques.

Question 1: What is the primary purpose of a two-level or more-level anterior cervical discectomy and fusion (ACDF)?

A) To perform a minimally invasive procedure B) To address cervical spine conditions affecting two or more adjacent cervical discs C) To relieve lumbar disc herniation D) To treat thoracic spine instability

Correct Answer: B) To address cervical spine conditions affecting two or more adjacent cervical discs

Question 2: Which of the following is NOT an indication for a two-level or more-level ACDF?

A) Severe degenerative disc disease involving two or more cervical levels B) Spinal stenosis affecting multiple cervical levels C) Lumbar disc herniation D) Spinal instability due to disc degeneration in multiple segments

Correct Answer: C) Lumbar disc herniation

Question 3: What type of anesthesia is typically used during a two-level or more-level ACDF procedure?

A) Local anesthesia B) Regional anesthesia C) General anesthesia D) Conscious sedation

Correct Answer: C) General anesthesia

Question 4: Which of the following is NOT a potential complication associated with multi-level ACDF?

A) Infection B) Graft problems C) Pain relief D) Hardware problems

Correct Answer: C) Pain relief

Question 5: What is the purpose of bone grafting in a two-level or more-level ACDF procedure?

A) To promote fusion of the vertebrae over time B) To remove damaged cervical discs C) To limit neck motion D) To replace the cervical vertebrae

Correct Answer: A) To promote fusion of the vertebrae over time

Question 6: According to the studies, what surgical approach resulted in greater global range of motion in the cervical spine?

A) Cervical disc arthroplasty (CDA) B) Anterior cervical discectomy and fusion (ACDF) C) Hybrid surgery (HS) D) Algorithmic approach

Correct Answer: C) Hybrid surgery (HS)

Question 7: What is heterotopic ossification (HO)?

A) Abnormal bone growth B) An imaging technique used in spine surgery C) A type of anesthesia D) A surgical instrument

Correct Answer: A) Abnormal bone growth

Question 8: What did the four-year results from a study by Davis et al. support regarding total disc replacement (TDR)?

A) TDR is less effective than ACDF for treating degenerative disc disease. B) TDR is not a safe surgical option for cervical spine conditions. C) TDR is a statistically superior alternative to ACDF for two contiguous cervical levels. D) TDR should not be considered for any cervical spine condition.

Correct Answer: C) TDR is a statistically superior alternative to ACDF for two contiguous cervical levels.

Question 9: Which group in the comparison study had a sequence of surgeries as CDA-ACDF-ACDF?

A) Type Ⅰa B) Type Ⅰb C) Type Ⅰc D) Control Group

Correct Answer: A) Type Ⅰa

Question 10: What surgical approach did Byvaltsev et al. use an algorithm to determine in their study?

A) Cervical disc arthroplasty (CDA) B) Total Disk replacement (TDR) C) Anterior cervical discectomy and fusion (ACDF) D) Minimally invasive surgery

Correct Answer: C) Anterior cervical discectomy and fusion (ACDF)