Adjacent Segment Degeneration In Patients Research Articles

Relationship between the postoperative variations of paraspinal muscles and adjacent-segment degeneration in patients with degenerative lumbar spinal stenosis after posterior instrumented lumbar fusion.

This study aimed to quantify pre- and postoperative paraspinal muscular variation following posterior lumbar interbody fusion (PLIF) in patients with degenerative lumbar spinal stenosis (DLSS) and measure the association of this variation with adjacent-segment degeneration (ASD). Data from 149 patients who underwent L4-S1 PLIF for DLSS were collected. Patients were divided into radiologically confirmed ASD and control groups according to follow-up radiological findings. MRI was performed before surgery and at the last follow-up. Muscular parameters including the relative cross-sectional area (rCSA), relative functional cross-sectional area (rFCSA), relative total cross-sectional area (rTCSA), and fatty infiltration (FI) of the multifidus (MF), erector spinae (ES), and psoas major (PM) muscles were measured on preoperative and follow-up L2-S1 MR images. Logistic regression was used to investigate risk factors for ASD. The rate of radiological ASD was 42.3% at the final follow-up (mean 25.71 ± 8.35 months). At surgical levels, the rFCSA and rTCSA of the MF and ES muscles decreased. The FI of the MF from L2-3 to L5-S1 and ES muscles at L5-S1 significantly increased after surgery, while the rFCSA and rTCSA of the PM muscle increased and its FI decreased. At adjacent levels, the rFCSA and rTCSA of the MF muscle and rTCSA of the ES muscle decreased and the FI of the MF muscle increased postoperatively (p < 0.05), but the rFCSA and rTCSA of the PM muscle increased and its FI decreased (p < 0.05). The FIs of the MF, ES, and PM muscles at adjacent levels significantly differed between the ASD and control groups. Logistic regression analysis indicated that higher BMI (p = 0.002) and FI of the PM muscle at adjacent levels (p = 0.025) were significant risk factors for ASD. The functional area decreased in the MF and ES muscles and increased in the PM muscle after L4-S1 PLIF. A compensatory postoperative decrease in FI of the PM muscle at the adjacent level was a protective factor for ASD in DLSS patients after PLIF.

Comparison of adjacent segment degeneration in patients using cervical cage and disc prosthesis in anterior cervical surgery

Comparison of adjacent segment degeneration in patients using cervical cage and disc prosthesis in anterior cervical surgery

Comparison of Clinical and Imaging Outcomes of Cervical Disc Replacement in Patients with Different Hounsfield Units

To compare clinical and imaging outcomes after cervical disc replacement (CDR) in patients with different Hounsfield units (HU). We performed a retrospective study of patients with cervical degenerative disc disease treated by 1-level and 2-level Prestige-LP arthroplasty. The patients were divided into group A (HU <320), group B (HU 320-347), and group C (HU >347) according to the results of cervical vertebral HU measurement in the literature, and the clinical and radiographic results were compared among the 3 groups. A total of 127 patients were reviewed, comprising 13 patients in group A, 31 patients in group B, and 83 patients in group C. The clinical parameters were significantly improved postoperatively in the 3 groups (P < 0.05). However, no significant differences were found among the 3 groups at the final follow-up (P > 0.05). The mean postoperative intervertebral space height (ISH) was 4.76 ± 0.45 mm, 5.23 ± 0.81 mm, and 6.26 ± 1.12 mm in the 3 groups, respectively. The postoperative ISH in group C was significantly higher than those in the other groups at the final follow-up (P < 0.001). One patient in group A and 1 patient in group B had implant subsidence, and degeneration at the inferiorly adjacent level was radiographically identified in 30.77% patients in group A, 16.13% patients in group B, and 9.64% patients in group C. However, there were only significant differences between group A and group C in subsidence (P= 0.011) and occurrence of adjacent level degeneration (P= 0.032). The HU value has a large variation range among the patients with T-score ≥ -2.5. We found significantly increased rates of implant subsidence, loss of ISH, and adjacent segment degeneration in patients with lower HU value undergoing CDR. However, these radiographic complications did not predispose patients with lower HU value to worse clinical outcomes. Routine application of HU combined with dual-energy X-ray absorptiometry measurement to evaluate bone quality may help to screen the optimal candidates for CDR and reduce the implant-related complications.

Preoperative paraspinal neck muscle characteristics predict early onset adjacent segment degeneration in anterior cervical fusion patients: A machine-learning modeling analysis.

Early onset adjacent segment degeneration (ASD) can be found within six months after anterior cervical discectomy and fusion (ACDF). Deficits in deep paraspinal neck muscles may be related to early onset ASD. This study aimed to determine whether the morphometry of preoperative deep neck muscles (multifidus and semispinalis cervicis) predicted early onset ASD in patients with ACDF. Thirty-two cases of early onset ASD after a two-level ACDF and 30 matched non-ASD cases were identified from a large-scale cohort. The preoperative total cross-sectional area (CSA) of bilateral deep neck muscles and the lean muscle CSAs from C3 to C7 levels were measured manually on T2-weighted magnetic resonance imaging. Paraspinal muscle CSA asymmetry at each level was calculated. A support vector machine (SVM) algorithm was used to identify demographic, radiographic, and/or muscle parameters that predicted proximal/distal ASD development. No significant between-group differences in demographic or preoperative radiographic data were noted (mean age: 52.4 ± 10.9 years). ACDFs comprised C3 to C5 (n = 9), C4 to C6 (n = 20), and C5 to C7 (n = 32) cases. Eighteen, eight, and six patients had proximal, distal, or both ASD, respectively. The SVM model achieved high accuracy (96.7%) and an area under the curve (AUC = 0.97) for predicting early onset ASD. Asymmetry of fat at C5 (coefficient: 0.06), and standardized measures of C7 lean (coefficient: 0.05) and total CSA measures (coefficient: 0.05) were the strongest predictors of early onset ASD. This is the first study to show that preoperative deep neck muscle CSA, composition, and asymmetry at C5 to C7 independently predicted postoperative early onset ASD in patients with ACDF. Paraspinal muscle assessments are recommended to identify high-risk patients for personalized intervention.

Late-onset neurological deficits induced by proximal adjacent segment degeneration related to severe post-tuberculous kyphotic deformities of the spine: a series of 7 cases and surgical correction concept.

Late-onset neurological deficits are a rare complication of spinal tuberculosis that may be caused by proximal adjacent segment degeneration (ASD) above the kyphus. The objective of this study was to report several cases of neurological deficits due to proximal ASD in patients with post-tuberculous kyphotic deformity and discuss the characteristics of the authors' corrective surgical technique. The inclusion criteria in this study were severe angular kyphosis due to a post-tuberculous kyphotic deformity and a late-onset neurological deficit. The cause of these deficits was related to a lesion in the proximal cephalad portion of the kyphotic deformity. Surgical intervention, including decompression and compromised restoration of the sagittal imbalance, was performed in all patients. Preoperative surgical planning with a radiological evaluation included CT, plain radiograph, and MRI studies. Clinical outcomes were evaluated using the American Spinal Injury Association Impairment Scale and the Oswestry Disability Index (ODI). The main goal of our surgical technique was the correction of sagittal malalignment by positioning the patient's head above the kyphotic deformity on the sagittal plane, excluding aggressive osteotomy. The neurological symptoms showed immediate improvements postoperatively, except in 1 patient. Compared to the preoperative value of 66.9, the mean ODI score improved to 42.6 at the final follow-up for all patients. Preoperatively, the mean values of the angles of deformity and the sagittal vertical axis were 99.7° and 157.7 mm, respectively, and decreased to 75.3° and 46.0 mm, respectively, at the final follow-up. No major complications were observed, and the patients' self-satisfaction was high with respect to both cosmetic and functional outcomes. Clinicians should be aware of the degeneration of the vertebrae above the kyphotic segment in patients with post-tuberculosis deformity. Successful neurological recovery and compromised sagittal balance could be obtained by using our "head on kyphus" surgical concept.

Preoperative Risk Factors for Adjacent Segment Degeneration after Two-Level Floating Posterior Fusion at L3-L5.

Introduction The aims of this study were to investigate how adjacent segment degeneration (ASD) occurs at the proximal and distal segments after L3-L5 fusion surgery, namely, floating fusion, and to identify the risk factors for ASD in patients who undergo this surgery. Methods Fifty patients who underwent floating fusion surgery at vertebrae L3-L5 and developed ASD were enrolled. The following parameters were evaluated: body mass index (BMI), diabetes status, dialysis status, lumbar lordosis, segmental lordosis between the L2 upper endplate and the L3 lower endplate, disc height, Cobb's angle, apical vertebral rotation using the Nash and Moe classification method, preoperative disc degeneration, surgical procedures, and the upper instrumented vertebra (UIV) tilt angle. The UIV tilt angle was defined as positive when the anterior side was directed caudally. Results Twenty-two (44%) of the 50 patients showed cephalad radiographic ASD (RASD) and 5 patients (10%) showed caudad RASD. Clinically symptomatic ASD was found at L2-L3 in 4 patients (8%) and at L5-S1 in 2 patients (4%). All the patients with clinically symptomatic cephalad ASD underwent revision procedures for radiculopathy or claudication because of degenerative pathology at L3-L4. Multivariate regression analysis showed a significant association of the absolute value of UIV tilt angle (mean |UIV tilt|) with cephalad RASD (odds ratio 1.09, p = 0.038). Receiver-operating characteristic curve analysis showed a significant association of |UIV tilt| >10.3° with RASD (sensitivity 67.9%, specificity 77.3%, area under the curve [AUC] 0.675). Conclusions RASD was more likely to occur at the adjacent segment on the cephalad side than at the adjacent segment on the caudad side after two-segment floating fusion of L3-L5. A preoperative UIV tilt angle >10° or UIV tilt < −10° was a risk factor for RASD.

Adjacent segment degeneration following spinal fusion of vertebral fractures in paraplegic patients

The effects of adjacent segment degeneration (ASD) after spinal fusion of vertebral fractures have previously not been demonstrated in patients with trauma-related paraplegia. The aim of this study was to evaluate the role of ASD in patients with paraplegia caused by vertebral fractures and to observe whether there is adifference between unilateral or combined spinal fusion in long-term results regarding the degeneration of cranial or caudal adjacent spinal segments. Atotal of 111 paraplegic patients with an average age of 45years who underwent spinal fusion of vertebral fractures were observed in aretrospective longitudinal study with afollow-up period of 4years. Conventional X‑ray images and magnetic resonance imaging (MRI) scans were used to assess the ASD in the adjacent free vertebral segments cranial and caudal to the spinal fusion using the following elements: ventral spondylophytes, intervertebral space, intervertebral disc signal in MRI, posterior spondylophytes, facet joint arthrosis, bone bridging and ossification of the anterior longitudinal ligament. Additionally, the classification by the American Spinal Injury Association (ASIA) impairment scale and spinal cord independence measure version3 score were surveyed. The 4‑year incidence of radiographically detectable ASD was 3-12 % in this study. The majority of ASDs were observed in the cranial segments adjacent to the interbody fusion. The dorsoventral spinal fusion showed the least effects on the adjacent segments. In conclusion, aconcept of prompt surgery using short dorsoventral segment fusion carried out by an interdisciplinary paralysis center is recommended. The role of natural degeneration processes and whether they are influenced by iatrogenic manipulation through the vertebral stabilization is unclear. For this reason it is important to further investigate strategies for ASD reduction in the future to ensure the best possible treatment success including the lowest degree of additional impairments for this special patient group.

Postoperative Radiographic Early-Onset Adjacent Segment Degeneration after Single-Level L4-L5 Posterior Lumbar Interbody Fusion in Patients without Preoperative Severe Sagittal Spinal Imbalance.

Study DesignRetrospective study.PurposeTo investigate the relationship between preoperative total spinal sagittal alignment and the early onset of adjacent segment degeneration (ASD) after single-level posterior lumbar interbody fusion (PLIF) in patients with normal sagittal spinal alignment.Overview of LiteraturePostoperative early-onset ASD is one of the complications after L4–L5 PLIF, a common surgical procedure for lumbar degenerative disease in patents without severe sagittal imbalance. A better understanding of the preoperative characteristics of total spinal sagittal alignment associated with early-onset ASD could help prevent the condition.MethodsThe study included 70 consecutive patients diagnosed with lumbar degenerative disease who underwent single-level L4–L5 PLIF between 2011 and 2015. They were divided into two groups based on the radiographic progression of L3–L4 degeneration after 1-year follow-up: the ASD and the non-ASD (NASD) group. The following radiographic parameters were preoperatively and postoperatively measured: sagittal vertebral axis (SVA), thoracic kyphosis (TK), lumbar lordosis, pelvic tilt, and pelvic incidence (PI).ResultsEight of the 70 patients (11%) experienced ASD after PLIF (three males and five females; age, 64.4±7.7 years). The NASD group comprised 20 males and 42 females (age, 67.7±9.3 years). Six patients of the ASD group showed decreased L3–L4 disc height, one had L3–L4 local kyphosis, and one showed both changes. Preoperative SVA, PI, and TK were significantly smaller in the ASD group than in the NASD group (p <0.05).ConclusionsA preoperative small SVA and TK with small PI were the characteristic alignments for the risk of early-onset ASD in patients without preoperative severe sagittal spinal imbalance undergoing L4–L5 single-level PLIF.

Adjacent segment degeneration after intervertebral fusion surgery by means of cervical block vertebrae.

The prevalence of cervical block vertebrae is unknown. Furthermore, there is no consensus on the cause of adjacent segment degeneration (ASD) after cervical fusion. (1) What is the incidence of cervical block vertebrae? Is there a gender difference? (2) Among cervical block vertebrae cases, is ASD related to age and segment? And what is the specific relationship? (3) What are the imaging findings and characteristics of this disease? We retrospectively diagnosed cervical block vertebrae cases with bony fusions in any segments of the cervical spine without intervertebral fusion surgery of 33,762 patients reported from 2006 to 2011 in north China. Then the X-ray of the obtained cases were observed and counted. The primary outcome was incidence of ASD according to age and segment. The secondary outcome measures were C2-7 angle in fusion (single segment fusion of lower cervical vertebra) and control groups (randomly selected cases of non-fusion), Cobb's angle of fusion segments, and curvature of each lower cervical segment in the control group. A total of 218 cervical block vertebrae cases were found, with a incidence of 0.65%, and C2-3 represented the highest number of fusion segment cases. There were no significant differences in the incidence by sex. Varying degrees of degeneration in the adjacent segment was present in 112 cases (51.4%). The incidence of ASD increased with age, with the ASD growth rate reaching its peak at the age of 51-60years (55.08%). Cervical curvature shows no significant difference between patients with cervical block vertebrae and normal individuals. The segmental curvature was lower in the fusion group than in the control group, with statistical significance achieved in fusion segments located in C4-5, C5-6, and C6-7, but not C3-4. Fusion segments located in C4-5, C5-6, and C6-7 are more prone to ASD than C3-4. The incidence of ASD in patients with vertebral fusion increases with age. III.

Risk factors of radiological adjacent disc degeneration with lumbar interbody fusion for degenerative spondylolisthesis.

Although various risk factors have been reported for adjacent segment degeneration after lumbar fusion, the exact mechanisms and risk factors related to adjacent segment degeneration have not been clear. The present study was conducted to evaluate the risk factors for radiological adjacent segment degeneration in patients surgically treated for single-level L4 spondylolisthesis focusing on a single pathology, a specific fusion level, at a set interval. We assessed preoperative and five-year postoperative radiographs for 72 patients who underwent L4-5 anterior or posterior lumbar interbody fusion for single-level L4 degenerative spondylolisthesis. Adjacent segment degeneration was defined as imaging evidence of one or more of the following conditions at L1-2, L2-3, or L3-4: 1) a loss of more than 20% of the preoperative disc height, 2) anterolisthesis or retrolisthesis greater than 3mm, 3) or osteophyte formation greater than 3mm. We found adjacent segment degeneration in 21 patients, with 31 discs affected. Multiple logistic regression analysis identified the following significant independent risk factors for adjacent segment degeneration: female gender (odds ratio 10.80; 95% confidence interval 1.20-96.89), posterior lumbar interbody fusion (odds ratio 7.70; 95% confidence interval 1.82-32.66), and pre-existing disc degeneration (odds ratio 12.29; 95% confidence interval 1.69-89.27). Female gender, posterior lumbar interbody fusion, and pre-existing disc degeneration were significant independent risk factors for radiologically diagnosed adjacent segment degeneration in patients treated for L4 degenerative spondylolisthesis by interbody lumbar fusion.

Radiological Signs of Adjacent Segment Degeneration Patients with Cervical Spondylotic Radiculopathy Treated with Posterior Cervical Cages: Two-Year Follow-Up

BACKGROUND CONTEXT: Select patients with nerve compression and cervical radiculopathy secondary to spondylosis can be successfully treated with indirect posterior cervical decompression and fusion with posterior cervical cages. Cervical fusion may have an influence on adjacent segment degeneration (ASD). PURPOSE: The aim of this study was to assess radiological signs of ASD at 2 years follow-up in patients treated with posterior cervical cages for cervical spondylotic radiculopathy. STUDY DESIGN/SETTING: Retrospective evaluation of cervical radiographs. PATIENT SAMPLE: Fifty-three patients who underwent posterior cervical fusion with DTRAX cervical cages for cervical spondylotic radiculopathy were enrolled into the study. The lateral cervical X-ray images were taken in neutral position preoperatively and at 1 and 2 years postoperatively. OUTCOME MEASURES: The adjacent levels were evaluation consisted of measurements of:1) Proximal junctional kyphosis (PJK);2) Disc height ratio (DHR) – ratio of the disc height and the lower vertebrae height measured in the in the middle;3) Heterotopic ossification (HO) – none,!50%, O50 % , complete bridging of the disc;4) Kellgren and Lawrence Osteoarthritis Severity Grade (OSG).5) Neck Disability Index(NDI), Visual Analog Scale(VAS), and SF-12 Mental(MCS) and Physical Component Score(PCS). METHODS: The results were compared with ANOVA test, with p!0.05 considered as significant. ASD was defined as an increase of HO or OSG by 1 grade in new cases and by 2 grades if pre-existing disc degeneration was present before surgery (DDS). RESULTS: There were no revision surgeries at the operated level or at adjacent levels. Disc degeneration signs were present before surgery (DDS) in 21 patients in upper level and in 22 patients in lower level. In 2 patients there were new grade 1 ASD changes, 1 in level above and 1 in level below at 2 years postoperatively. In patients with pre-existing disc degeneration at the adjacent level, there were 0 cases of adjacent level degeneration progression of 2 grade or more. There were no significant changes in DHR and in PJK in all patients and in patients with ASD, however, there were tendency in patients with signs of ASD to decrease DHR in time. The mean PJK before surgery was -1.02 64.6 , 1 year after surgery -0.86 64.7 and 2 years after surgery was -0.59 65.4 ; p50.5342The mean DHR in all patients before surgery was 43.3 66.3 , 1 year after surgery 43.3 66.6 and 2 years after surgery was 43.1 66.8 ; p50.7290The mean DHR in ASD patients before surgery was 44.1 65.6 , 1 year after surgery 42.667.2 and 2 years after surgery was 40.9 67.8 ; p50.1836.The mean preop and 2-year scores were: NDI: 32.3 vs 9.1 (p!0.0001); VAS Neck Pain: 7.4 vs 2.6(p!0.0001); VAS Arm Pain: 7.4 vs 2.6 (p!0.0001); SF-12 PCS: 34.6 vs 43.6(p!0.0001) and SF-12 MCS: 40.8 vs 51.4 (p!0.0001). CONCLUSIONS: Indirect decompression and posterior cervical fusion using the DTRAX Cage may be an effective option in select patients with single level cervical radiculopathy. In patients treated with posterior cervical cage progression of disc degeneration is much more common on the basis of preoperative changes than new ASD. Posterior cervical fusion with cervical cage does not induce or accelerate adjacent segment degeneration in the great majority of patients (more than 1 score). Further evaluation to establish long-term incidence of ASD in patients treated with posterior cervical cage is needed. FDA DEVICE/DRUG STATUS: DTRAX Cervical Cage (Providence Medical Technology, Inc.) (Approved for this indication).

Prevalence of adjacent segment disc degeneration in patients undergoing anterior cervical discectomy and fusion based on pre-operative MRI findings

Anterior cervical discectomy and fusion (ACDF) is a widely accepted surgical treatment for symptomatic cervical spondylosis. Some patients develop symptomatic adjacent segment degeneration, occasionally requiring further treatment. The cause and prevalence of adjacent segment degeneration and disease is unclear at present. Proponents for motion preserving surgery such as disc arthroplasty argue that this technique may decrease the “strain” on adjacent discs and thus decrease the incidence of symptomatic adjacent segment degeneration. The purpose of this study was to assess the pre-operative prevalence of adjacent segment degeneration in patients undergoing ACDF. A database review of three surgeons’ practice was carried out to identify patients who had undergone a one- or two-level ACDF for degenerative disc disease. Patients were excluded if they were operated on for recent trauma, had an inflammatory arthropathy (for example, rheumatoid arthritis), or had previous spine surgery. The pre-operative MRI of each patient was reviewed and graded using a standardised methodology. One hundred and six patient MRI studies were reviewed. All patients showed some evidence of intervertebral disc degeneration adjacent to the planned operative segment(s). Increased severity of disc degeneration was associated with increased age and operative level, but was not associated with sagittal alignment. Disc degeneration was more common at levels adjacent to the surgical level than at non-adjacent segments, and was more severe at the superior adjacent level compared with the inferior adjacent level. These findings support the theory that adjacent segment degeneration following ACDF is due in part to the natural history of cervical spondylosis.

Analysis of adjacent segment degeneration with laminectomy above a fused lumbar segment

Although recent data suggests that lumbar fusion with decompression contributes to some marginal acceleration of adjacent segment degeneration (ASD), few studies have evaluated whether it is safe to perform a laminectomy above a fused segment. This study investigates the hypothesis that laminectomy above a fused lumbar segment does not increase the incidence of ASD, and assesses the benefits and risks of performing a laminectomy above a lumbar fusion. A retrospective review of 171 patients who underwent decompression and instrumented fusion of the lumbar spine was performed to analyze the association between ASD and laminectomy above the fused lumbar segment. Patients were divided into two groups – one group with instrumented fusion alone and the other group with instrumented fusion plus laminectomy above the fused segment. Of the 171 patients, 34 underwent additional decompressive laminectomy above the fused segment. There was a significant increase in ASD incidence as well as progression of ASD grade in both groups. There was no significant increase in ASD in patients with decompressive laminectomy above the fused lumbar segment compared to patients with laminectomy limited to the fused segment. This retrospective review of 171 patients who underwent decompression and instrumented fusion with follow-up radiographs demonstrates that laminectomy decompression above a fused segment does not significantly increase radiographic ASD. There is, however, a significant increase in ASD over time, which was observed throughout the entire cohort likely representing a natural progression of lumbar spondylosis above the fusion segment.

Prevalence of Adjacent Segment Degeneration After Spine Surgery

Systematic review of published prevalence of adjacent segment degeneration (ASD) after spine surgery. To evaluate the prevalence of ASD in patients after cervical and lumbar spine surgery. ASD is a common complication after spine surgery in long-term follow-up. A large body of literature has been reported on the topic, but no meta-analysis of the epidemiological data on ASD has been published We searched the MEDLINE until March 2012 published in English language that reported the prevalence of ASD after spine surgery. We determined the ASD rates by calculating proportions and 95% confidence interval (CI) for each study and then pooled the data to derive a pooled proportion and 95% CI. A total of 94 studies with 34,716 patients from 19 countries were included. The occurrence of radiograph ASD ranged from 4.8% to 92.2%, and the pooled prevalence was 29.3% (95% CI, 22.7%-35.8%) by the random-effects model. The occurrence of symptoms ASD ranged from 0.0% to 30.3%, and the pooled prevalence was 7.4% (95% CI, 6.4%-8.5%). In cervical position, the occurrence of radiograph ASD and symptoms ASD was 32.8% (95% CI, 17.8%-47.9%) and 6.3% (95% CI, 4.8%-7.8%); in lumbar position, the occurrence of radiograph ASD and symptoms ASD was 26.6% (95% CI, 21.3%-31.9%) and 8.5% (95% CI, 6.4%-10.7%). In the 0.5- to 2- or less, more than 2- to 5- or less, and more than 5- to 20- or less year diagnosis time, the radiograph ASD prevalence was 21.8% (16.0%-27.6%), 33.6% (21.8%-45.4%), and 37.4% (10.7%-64.1%), respectively; and the symptoms ASD prevalence was 6.5% (4.8%-8.1%), 12.1% (8.2%-16.0%), and 3.2% (2.5%-4.0%), respectively. Spine surgery is associated with significant risk of ASD. These figures may be useful in the estimation of the burden of the ASD after spine surgery.

Evaluation of Adjacent Segment Degeneration after Cervical Spine Surgery: Arthroplasty versus Fusion

Background: Anterior Cervical Discectomy and Fusion (ACDF) is an effective treatment for disc herniations; but some studies demonstrated that in the untreated levels adjacent to a fusion, increased motion might lead to an increased risk of adjacent segment degeneration (ASD). On the other hand, methods of cervical Disc Arthroplasty (CDA) have improved. The aim of this study is to evaluate and compare the rate of ASD in patients who underwent ACDF or CDA cervical spine surgery.&#x0D; Methods and Materials: This prospective study was performed on 84 patients with cervical radiculopathy due to single-level disc herniation referred to hospitals in Tehran, Iran from June 2011 to December 2012. All subjects were randomly allocated to Group A or Group B to undergo ACDF or CDA, respectively. The validated Neck Disability Index (NDI) questionnaire was used to assess the cervical neck pain.&#x0D; Results: The mean of age in Group A was 51.7 ± 9.1 years and in Group B was 49.3 ±9.2. The differences in cervical radiculopathy in the two groups were not statistically significant. The difference in mean Visual Analogue Scale (VAS) score in the two groups at each assessment time was statistically significant. Mean NDI score before the surgery was 46.9 ± 6.1 in group A, and 41.3 ±4.7 in group B. The mean NDI score improved significantly in group B. Twenty-seven of the patients in Group A experienced ASD at 12 months compared to one patient (2.3%) in Group B (p&lt;0.05).&#x0D; Conclusion: According to the findings of this study, CDA leads to reduced VAS and NDI score compared to ACDF. Also increased ASD in ACDF was demonstrated when compared with CDA after 1-year follow-up.