Pre-existing Disc Degeneration Research Articles

Impact of Preoperative Intervertebral Disc Degeneration on Patient-Reported Outcome Measures After Lumbar Fusion

The Pfirrmann scoring system classifies lumbosacral disc degeneration based on MRI signal intensity. The relationship between pre-existing disc degeneration and PROMs after one-level lumbar fusion is not well documented. The purpose of this study was to investigate the relationship between the severity of preoperative intervertebral disc degeneration and pre- and postoperative patient-reported outcome measures (PROMs) in patients undergoing one-level lumbar fusion. All adult patients underwent posterior lumbar decompression and fusion (PLDF) or transforaminal lumbar interbody fusion (TLIF) between 2014-2022 were included. Patient demographics, and comorbidities were extracted from medical records. Lumbar intervertebral discs on sagittal MRI T2-weighted images were assessed by two independent graders utilizing Pfirrmann criteria. Grades I-III were categorized as low-grade disc degeneration, while IV-V were considered high-grade. Multivariable linear regression assessed the impact of disc degeneration on PROMS. A total of 150 patients were included, of which, 69 (46%) had low grade disc degeneration, while 81 (54%) had high grade degeneration. Patients with high-grade degeneration had increased preoperative VAS-Leg scores (6.10 vs. 4.54, p=0.005) and displayed greater one-year postoperative improvements in VAS-Back scores (-2.11 vs -0.66, p=0.002). Multivariable regression demonstrated Pfirrmann scores as independent predictors for both preoperative VAS-Leg scores (p=0.004) and postoperative VAS-Back improvement (p=0.005). In patients undergoing one-level lumbar fusion, higher Pfirmann scores were associated with increased preoperative leg pain and greater one-year postoperative improvement in back pain. Further studies into the relationship of pre-operative disc degeneration and their impact on postoperative outcomes may help guide clinical decision making and patient expectations.

The lumbar adjacent-level syndrome: analysis of clinical, radiological, and surgical parameters in a large single-center series.

The development of specific clinical and neurological symptoms and radiological degeneration affecting the segment adjacent to a spinal arthrodesis comprise the framework of adjacent-level syndrome. Through the analysis of a large surgical series, this study aimed to identify possible demographic, clinical, radiological, and surgical risk factors involved in the development of adjacent-level syndrome. A single-center retrospective analysis of adult patients undergoing lumbar fusion procedures between January 2014 and December 2018 was performed. Clinical, demographic, radiological, and surgical data were collected. Patients who underwent surgery for adjacent-segment disease (ASD) were classified as the ASD group. All patients were evaluated 1 month after the surgical procedure clinically and radiologically (with lumbar radiographs) and 3 months afterward with CT scans. The last follow-up was performed by telephone interview. The median follow-up for patients included in the analysis was 67.2 months (range 39-98 months). A total of 902 patients were included in this study. Forty-nine (5.4%) patients required reoperation for ASD. A significantly higher BMI value was observed in the ASD group (p < 0.001). Microdiscectomy and microdecompression procedures performed at the upper or lower level of an arthrodesis without fusion extension have a statistically significant impact on the development of ASD (p = 0.001). Postoperative pelvic tilt in the ASD group was higher than in the non-ASD group. Numeric rating scale, Core Outcome Measures Index, and Oswestry Disability Index scores at the last follow-up were significantly higher in patients in the ASD group and in patients younger than 65 years. Identifying risk factors for the development of adjacent-level syndrome allows the implementation of a prevention strategy in patients undergoing lumbar arthrodesis surgery. Age older than 65 years, high BMI, preexisting disc degeneration at the adjacent level, and high postoperative pelvic tilt are the most relevant factors. In addition, patients older than 65 years achieve higher levels of clinical improvement and postsurgical satisfaction than do younger patients.

Impact of adjacent pre-existing disc degeneration status on its biomechanics after single-level anterior cervical interbody fusion

Background and objectiveMechanics and biology may be interconnected and amplify each other during disc degeneration. It remains unknown the influence of pre-existing disc degeneration and its impact on adjacent segment degeneration (ASD) after anterior cervical discectomy and fusion (ACDF). This study aimed to discuss the necessity of including degenerated adjacent segments in single-level ACDF surgery from a biomechanical view. MethodsA poroelastic C2-T1 finite element model was created and validated. A C5-C6 ACDF model was developed based on this normal model. Moderate C4-C5 disc degeneration was created by appropriately modifying the morphology and tissue material properties in this fusion model. Degenerative morphology was modeled based on Thompson's grading system and Walraevens's scoring system for cervical spine, including disc height, whole disc area, nucleus pulposus (NP) area, endplate sclerosis and curvature. Stresses in disc and endplate and loads in facet joint were computed under moment loads in the fusion models with normal and pre-existing degenerative disc condition. ResultsAs for the adjacent disc, the stress values in degenerative condition were 7.41%, 5% and 5.26% larger than that in normal situation during extension, axial rotation and lateral bending motion, respectively. The disc stress changes mainly stemmed from annulus fibrosus (AF) tissue, but not NP. In the endplate, stress values of degeneration status were 4.17, 4.35 and 6.06% larger than that of normal condition under axial rotation, lateral bending and extension. The facet load magnitudes of pre-existing degeneration were 11.28, 11.57, 11.78 and 11.42% greater than that of normal condition in flexion, extension, axial rotation and lateral bending motion. ConclusionPre-existing degenerated disc experience increased biomechanical changes in adjacent segment after single-level ACDF. It may pose a long-term cumulative problem related to biomechanics in cervical spine after fusion. Before surgery, surgeons should be careful about selecting the fusion level.

Is Preexisting Cervical Degeneration a Risk Factor for Poor Prognosis in Whiplash-Associated Disorder?

The term whiplash describes the acceleration-deceleration mechanism of injury to the cervical spine. Whiplash injuries present with a variety of clinical and psychological manifestations, collectively termed as whiplash-associated disorders (WADs). Although largely self-limiting, some patients may experience long-lasting symptoms. This review aimed to summarize the current literature regarding the predictive value of cervical degeneration in the prognosis of patients with WAD. A comprehensive search of the literature was performed. Nine studies were identified, including 894 patients, with an age range between 16 and 76 years. A statistically significant association was found between moderate facet joint degeneration and nonrecovery. Although no association was established between isolated disc degeneration and nonrecovery, total cervical degeneration (facet joint + disc degeneration) was shown to correlate with nonrecovery.All included studies demonstrated the lack of correlation between preexisting disc degeneration and clinical outcomes. Four studies showed a significant correlation between cervical degeneration and poor prognosis following whiplash injury. A significantly higher proportion of patients who remained symptomatic at 2 years following a whiplash injury had preexisting degenerative changes. This review highlights the presence of significant variability in the existing literature concerning WAD in terms of study methodology, definitions of cervical degeneration, and outcome measures. Degenerative changes of the facet joint lead to alterations in its biomechanics. Several cadaveric, biomechanical, and clinical studies have demonstrated facet joints as a source of pain in patients with chronic WAD. We present moderate evidence to suggest that preexisting facet joint degeneration is a negative prognostic indicator for long-lasting symptoms in WAD. Conversely, preexisting disc degeneration is not associated with chronicity of WAD symptoms. We propose facet joint instability due to facet joint capsule rupture as a potential mechanism for nonrecovery. Further studies are needed to inform our knowledge of the long-term sequelae of WAD among patients with preexisting cervicalspine degeneration.

Modic changes in the cervical spine: Prospective 20-year follow-up study in asymptomatic subjects

BackgroundFew studies have characterized the development of Modic changes in the cervical spine over time. We evaluated Modic changes of the cervical spine that developed over a 20-year period in a healthy cohort, and sought to clarify the relationship between Modic changes and the development of clinical symptoms. MethodsFor this multicenter prospective cohort study, we recruited 193 subjects from an original cohort of asymptomatic volunteers who underwent MRI of the cervical spine between 1993 and 1996. Each cervical level from C2/3 to C7/T1 (total n = 1158 intervertebral levels) was assessed on current MRIs as normal or showing type 1, 2, or 3 Modic change, and we asked about symptoms related to the cervical spine. Relationships between the presence of Modic changes and patient characteristics, pre-existing disc degenerations or clinical symptoms were evaluated by logistic regression analysis. ResultsAfter 20-year follow-up, Modic changes affected 31 subjects (16.1%) at 47 intervertebral disc levels. Of these 47 intervertebral disc levels, type 2, found at 30 levels (63.8%), was the most frequent, followed by type 1 at 15 levels (31.9%) and type 3 at two levels (4.3%). The most frequent changes were observed at the C5/6 segment with type 2 Modic changes. The presence of Modic changes correlated with pre-existing posterior disc protrusion (odds ratio 3.31, 95% confidence interval 1.21–9.05) and neck pain (odds ratio 2.71, 95% confidence interval 1.08–6.80). ConclusionsIn the cervical spine over a 20-year period, type 2 Modic changes were most frequent at the C5/6 segment. The Modic changes were associated with pre-existing disc degeneration and neck pain but not with age, BMI, smoking, shoulder stiffness, arm pain or numbness.

Adjacent segment degeneration after fusion spinal surgery-a systematic review.

Adjacent segment degeneration (ASDeg) and disease (ASDis) have become major concerns after fusion surgery. However, there is no definitive data or knowledge about the incidence or risk factors. The review discusses the incidence and risk factors and prevention of ASDeg and ASDis in the relevant literature. We performed a systematic review of meta-analyses, randomized control trials, and cohort studies published in English to provide evidence-based information about ASDeg and ASDis. According to a meta-analysis, the pooled incidence of ASDeg after lumbar and cervical fusion surgery was 26.6% and 32.8%, respectively. Approximately 1/4-1/3 of ASDeg progressed to ASDis. Risk factors after cervical fusion surgery were young age, pre-existing disc degeneration, short fusion segment, high T1 slope, disruption of adjacent soft tissue, and plate placement close to the adjacent disc. The risk factors of ASDeg and ASDis after lumbar fusion surgery were age, genetic factors, high body mass index, pre-existing adjacent segment degeneration, laminectomy at the adjacent level of fusion, excessive distraction of the fusion level, insufficient lumbar lordosis, multilevel fixation, floating fusion, coronal wedging of L5-S disc, pelvic tilt, and osteoporosis. Motion-preserving surgeries seem to have less risk of ASDeg and ASDis than conventional fusion surgery both in the lumbar and cervical spine. The existent literature points out variables involved in ASDeg and ASDis. High evidence-level studies should provide more relevant data to guide strategies for avoiding ASDeg and ASDis.

Adjacent segment disease after instrumented fusion for adult lumbar spondylolisthesis: Incidence and risk factors

ObjectiveA potential long-term complication of lumbar fusion is the development of adjacent segment disease (ASD), which may necessitate second surgery and adversely affect outcomes. The objective of this is to determine the incidence of ASD following instrumented fusion in adult patients with lumbar spondylolisthesis and to identify the risk factors for this complication. Patients and methodsWe retrospectively assessed adult patients who had undergone decompression and instrumented fusion for lumbar spondylolisthesis between January 2006 and December 2012. The incidence of ASD was analyzed. Potential risk factors included the patient-related factors, surgery-related factors, and radiographic variables such as sagittal alignment, preexisting disc degeneration and spinal stenosis at the adjacent segment. ResultsA total of 154 patients (mean age, 58.4 years) were included. Mean duration of follow-up was 28.6 months. Eighteen patients (11.7%) underwent a reoperation for ASD; 15 patients had reoperation at cranial ASD and 3 at caudal ASD. The simultaneous decompression at adjacent segment (p=0.002) and preexisting spinal stenosis at cranial adjacent segment (p=0.01) were identified as risk factors for ASD. The occurrence of ASD was not affected by patient-related factors, the types, grades and levels of spondylolisthesis, surgical approach, fusion procedures, levels of fusion, number of levels fused, types of bone graft, use of bone morphogenetic proteins, sagittal alignment, preexisting adjacent disc degeneration and preexisting spinal stenosis at caudal adjacent segments. ConclusionOur findings suggest the overall incidence of ASD is 11.7% in adult patients with lumbar spondylolisthesis after decompression and instrumented fusion at a mean follow-up of 28.6 months, the simultaneous decompression at the adjacent segment and preexisting spinal stenosis at cranial adjacent segment are risk factors for ASD.

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).

The fate of adjacent segments with pre-existing degeneration after lumbar posterolateral fusion: the influence of degenerative grading.

To evaluate the impact of pre-existing disc degeneration and its extent on future adjacent segment degeneration (ASDeg) after lumbar posterolateral fusion (PLF). A total of 102 patients who had undergone PLF for degenerative lumbar diseases from January 2006 to December 2008 were retrospectively reviewed by using radiography and clinical evaluation. The University of California at Los Angeles (UCLA) grading scale was used to evaluate the extent of disc degeneration. The Visual Analog Scale, Oswestry Disability Index, and SF-36 questionnaire were used to evaluate clinical outcomes. The overall prevalence of radiological ASDeg was 25.5 %, and the prevalence of ASDeg for the cranial and caudal levels was 19.6 and 15.1 %, respectively. The prevalence of ASDeg in one-, two-, and three-level fusion was 15.8, 26.3, and 50 %, respectively (p = 0.008). For the cranial level, the preoperative UCLA grade A, B, and C groups had prevalence values for ASDeg of 13.5, 28.6, and 42.9 %, respectively (p = 0.026). A higher prevalence of ASDeg was found in cranial discs with pre-existing degeneration than in the group without pre-existing degeneration (p = 0.012). The group without pre-existing degeneration showed better outcomes. For the caudal level, there was no significant difference in ASDeg prevalence. At final follow-up, the group without pre-existing disc degeneration showed better outcomes than the group with pre-existing disc degeneration. Adjacent segment discs with pre-existing degeneration had a higher likelihood of ASDeg progression compared with normal discs, especially for those classified as UCLA grade C.

Modic changes of the cervical spine in patients with whiplash injury: A prospective 11-year follow-up study

IntroductionThere are few studies on Modic changes of the cervical spine in patients suffering from whiplash. This study compared Modic changes seen in whiplash patients 10 years after the injury with those observed in asymptomatic volunteers. MethodsThis is a follow-up study of 133 patients who suffered whiplash injuries in 1994–1996 and underwent MRI with a superconductive imager (63 men, 70 women, mean age 49.6±15.3 years, mean follow-up 11.4 years). In addition, 223 healthy volunteers who underwent MRI during the same period were included as controls (123 men, 100 women, mean age 50.5±15.0 years, mean follow-up 11.6 years). All participants underwent follow-up MRI. We examined all participants for Modic changes, and investigated relationships between Modic changes and clinical symptoms or potentially related factors. ResultsModic changes were observed in 4 patients (3%) and at 7 intervertebral levels in the initial study, and in 17 patients (12.8%) and at 30 intervertebral levels at the follow-up. Modic Type 2 changes were the most prevalent in the whiplash patients in both the initial and follow-up studies. There was no significant difference in the percentage of whiplash patients versus control subjects with positive Modic changes, either at the initial study or at follow-up. Modic changes were not related to clinical symptoms present at follow-up, but were associated with preexisting disc degeneration. There was no association between Modic changes and the details of the car accident that caused the injury. ConclusionsWhile Modic changes became more common in whiplash patients in the 10-year period after the accident, they occurred with a similar frequency in control subjects. We did not find any association between Modic changes and the nature of the car accident in which the whiplash occurred. Modic changes found in whiplash patients may be a result of the physiological ageing process rather than pathological findings relating to the whiplash injury.

Modic changes in the cervical spine

We conducted a prospective follow-up MRI study of originally asymptomatic healthy subjects to clarify the development of Modic changes in the cervical spine over a ten-year period and to identify related factors. Previously, 497 asymptomatic healthy volunteers with no history of cervical trauma or surgery underwent MRI. Of these, 223 underwent a second MRI at a mean follow-up of 11.6 years (10 to 12.7). These 223 subjects comprised 133 men and 100 women with a mean age at second MRI of 50.5 years (23 to 83). Modic changes were classified as not present and types 1 to 3. Changes in Modic types over time and relationships between Modic changes and progression of degeneration of the disc or clinical symptoms were evaluated. A total of 31 subjects (13.9%) showed Modic changes at follow-up: type 1 in nine, type 2 in 18, type 3 in two, and types 1 and 2 in two. Modic changes at follow-up were significantly associated with numbness or pain in the arm, but not with neck pain or shoulder stiffness. Age (≥ 40 years), gender (male), and pre-existing disc degeneration were significantly associated with newly developed Modic changes. In the cervical spine over a ten-year period, type 2 Modic changes developed most frequently. Newly developed Modic changes were significantly associated with age, gender, and pre-existing disc degeneration.

Accelerated L5-S1 Segment Degeneration after Spinal Fusion on and above L4-5 : Minimum 4-Year Follow-Up Results

Many biomechanical and clinical studies on adjacent segment degeneration (ASD) have addressed cranial segment. No study has been conducted on caudal segment degeneration after upper segment multiple lumbar fusions. This is a retrospective investigation of the L5-S1 segment after spinal fusion at and above L4-5, which was undertaken to analyze the rate of caudal ASD at L5-S1 after spinal fusion on and above L4-5 and to determine that factors that might have influenced it. The authors included 67 patients with L4-5, L3-5, or L2-5 posterior fusions. Among these patients, 28 underwent L4-5 fusion, 23 L3-5, and 16 L2-5 fusions. Pre- and postoperative radiographs were analyzed to assess degenerative changes at L5-S1. Also, clinical results after fusion surgery were analyzed. Among the 67 patients, 3 had pseudoarthrosis, and 35 had no evidence of ASD, cranially and caudally. Thirteen patients (19.4%) showed caudal ASD, 23 (34.3%) cranial ASD, and 4 (6.0%) both cranial and caudal ASD. Correlation analysis for caudal ASD at L5-S1 showed that pre-existing L5-S1 degeneration was most strongly correlated. In addition, numbers of fusion segments and age were also found to be correlated. Clinical outcome was not correlated with caudal ASD at L5-S1. If caudal and cranial ASD are considered, the overall occurrence rate of ASD increases to 50%. The incidence rate of caudal ASD at L5-S1 was significantly lower than that of cranial ASD. Furthermore, the occurrence of caudal ASD was found to be significantly correlated with pre-existing disc degeneration.