Effect of aging and degeneration on disc volume and shape: A quantitative study in asymptomatic volunteers

Morphometric and Morphological Study of Thoracic and Lumbar Intervertebral Discs in Guinea Pigs (Cavia porcellus)

This study investigates the gross morphological and morphometric characteristics of thoracic and lumbar intervertebral discs (IVDs) in guinea pigs, utilising micro-CT imaging and anatomical dissection. The findings reveal 13 thoracic and six lumbar IVDs were identified, with thoracic discs transitioning from rounded forms at T1-T3 to triangular and heart-shaped structures at T4-T13, while lumbar IVDs exhibited a consistently flattened heart shape. Morphometric analysis revealed statistically significant differences, with lumbar IVDs being larger in lateral and dorsoventral width, disc area, annulus fibrosus (AF) area and nucleus pulposus (NP) area, and ventral height compared to thoracic discs. Specifically, significant increases in lateral width and disc area were observed in lumbar segments L5 and L6, while thoracic IVDs demonstrated fluctuating alterations in some parameters, such as dorsal and ventral height. Histologically, both thoracic and lumbar IVDs feature a well-organised NP, AF and endplates (EP). The EP was composed of cartilaginous materials, including hyaline cartilage, fibrocartilage and calcified cartilage, and bony materials, including extensive secondary ossification centres with many large vascular channels and bone trabeculae. In conclusion, this study indicates that although thoracic and lumbar IVDs conserve key histological properties, their distinct morphological and morphometric characteristics in guinea pigs reflect their adaptations to biomechanical demands. However, due to some fundamental differences between human and guinea pig, use of this species as a model for human IVD research and interpreting the extracted data should be cautious.

Lumbar disc space height in relation to neural foraminal dimensions and patient characteristics: A morphometric analysis from L1-S1 using computed tomography

Introduction

The normative relationship between lumbar intervertebral disc space height (DSH) and neuroforaminal dimensions (NFD) has yet to be defined.

Research question

The purpose of this study was to investigate the relationship between lumbar DSH and NFD using computed tomography (CT), accounting for influences of patient demographic and anthropometric characteristics.

Materials and methods

We analyzed CT imaging of 350 female and 350 male patients. Anterior, middle, and posterior DSH were measured. NFD were defined as sagittal anterior-to-posterior (AP) width, axial AP width, foraminal height, and area. Statistical analyses were performed to assess associations among DSH, NFD, and patient height, weight, body mass index, sex, and ethnicity.

Results

Irrespective of disc level, mean anterior, middle, and posterior DSH were 7.98 mm (n = 3500), 8.16 mm (n = 3500), and 4.09 mm (n = 3500). DSH measurements demonstrated increasing, linear trends moving caudally from L1-L2 to L5-S1, while NFD demonstrated a unimodal distribution pattern with largest NFD at L3-L4 and smallest NFD at L1-2 and L5-S1. Male patients demonstrated larger DSH compared to female patients from L1-S1. Asian patients demonstrated taller DSH across all levels L1-S1.

Discussion and conclusion

This study describes 38,500 CT-based L1-S1 DSH and NFD in young patients without spinal pathology. DSH follows an increasing trend moving caudally from L1-S1, while NFD demonstrate a unimodal distribution clustered at L3-L4. NFD are not moderately or strongly associated with DSH. DSH is influenced by sex and ethnicity but is not moderately or strongly influenced by patient height, weight, and BMI.

Immediate Effects, Detailed Clinical Outcomes, and Prognostic Factors of Chemonucleolysis Using Condoliase for Lumbar Disc Herniation

Chemonucleolysis utilizing condoliase is a minimally invasive treatment for lumbar disc herniation (LDH) aimed at reducing intervertebral disc pressure and enhancing symptoms. In this study, lower limb pain was measured using the numeric rating scale (NRS) the day after treatment and 1 and 3 months after treatment. Prognostic factors were assessed, categorizing participants into an improvement group (I-group) for NRS lower limb pain scores of ≥3.5 and a non-improvement group (N-group) for scores of <3.5. This study included a total of 225 patients treated between April 2020 and March 2023. The mean age was 46.5 ± 16.5 years, with 151 males. The mean duration of illness was 6.2 ± 8.52 months. As of the day after treatment, 60 cases were classified into the I-group, 118 cases at 1 month after surgery, and 152 cases at 3 months after surgery. The disease duration before treatment was significantly shorter in the I-group at 1 (8.19 ± 8.74 [I-group] vs. 5.17 ± 8.04 [N-group] months) and 3 months (8.51 [I-group] ± 7.35 vs. 5.69 ± 8.87[N-group] months) after treatment. The comparison of baseline leg pain NRS shows a difference in leg pain NRS in the I-group when compared on the day after treatment (6.02 ± 2.64 [I-group] vs. 7.50 ± 1.79 [N-group]), 1 (5.13 ± 2.69 [I-group] vs. 7.58 ± 1.66 [N-group]), and 3 months (4.42 ± 2.70 [I-group] vs. 7.34 ± 1.77 [N-group]). Chemonucleolysis using condoliase for LDH can improve symptoms the day after treatment and can be a minimally invasive treatment to avoid surgery.

Normative Measurements of L1-S1 Segmental Angulation, Disk Space Height, and Neuroforaminal Dimensions Using Computed Tomography

BACKGROUND AND OBJECTIVES

To establish normative anatomic measurements of lumbar segmental angulation (SA) and disk space height (DSH) in relation to neuroforaminal dimensions (NFDs), and to uncover the influence of patient demographic and anthropometric characteristics on SA, DSH, and NFDs.

METHODS

NFDs, SA, and anterior, middle, and posterior DSH were measured using computed tomography of 969 patients. NFDs were defined as sagittal anterior-to-posterior width, foraminal height, and area. Statistical analyses were performed to assess associations among SA, DSH, NFDs, and patient height, weight, body mass index, sex, and ethnicity.

RESULTS

SA and DSH measurements increased moving caudally from L1 to S1. Foraminal width decreased moving caudally from L1 to S1. Foraminal height and area demonstrated unimodal distribution patterns with the largest values clustered at L2-L3 on the right side and L3-L4 on the left. Significant differences in SA, DSH, and NFD measurements were observed based on the disk level. Inconsistent, marginal NFD differences were observed based on laterality. Across all disk levels, only weak-to-moderate correlations were observed between SA and DSH in relation to NFDs. Patient height, weight, and body mass index were only weakly associated with SA, DSH, and NFDs. Based on patient sex, significant differences were observed for SA, DSH, and NFD measurements from L1 to S1, with males demonstrating consistently larger values compared with females. Based on patient race and ethnicity, significant differences in SA and NFD measurements were observed from L1 to S1.

CONCLUSION

This study describes 48 450 normative measurements of L1-S1 SA, DSH, and NFDs. These measurements serve as representative models of normal anatomic dimensions necessary for several applications including surgical planning and diagnosis of foraminal stenosis. Normative values of SA and DSH are not moderately or strongly associated with NFDs. SA, DSH, and NFDs are influenced by sex and ethnicity, but are not strongly or moderately influenced by patient anthropometric factors.

Modic changes in the lumbar vertebral column of chondrodystrophic and non-chondrodystrophic dogs with intervertebral disc disease

Introduction

Modic changes (MC) are signs of vertebral pathology visible on magnetic resonance (MR) images that have been associated with low back pain (LBP) and disc degeneration in people. Multiple breeds of dogs also develop MCs and coincident back pain. However, the association between breed, MC, and spinal pathologies has yet to be fully elucidated. This study aimed to identify the prevalence of MC that occur spontaneously in the lumbar vertebral column of dogs diagnosed with intervertebral disc disease (IVDD) and examine their association with demographic criteria and the disc width index (DWI).

Methods

Medical records and lumbar vertebral column MR images were examined from 104 dogs (831 intervertebral disc spaces and adjacent vertebrae), which were divided into three groups: chondrodystrophic dogs (CD; n =54) and non-chondrodystrophic dogs (NCD; n =30) with IVDD as the primary diagnosis, and control dogs (n =20) with other spinal diseases as their primary diagnosis.

Results

Increasing age and a diagnosis of IVDD were significantly associated with MC in dogs (p <  0.001 and p = 0.0062, respectively). In CD dogs with IVDD, Type 2 MC were most prevalent, whereas, in NCD dogs, Type 3 MC were the most prevalent type. Type 2 MC were distributed nearly equally across the lumbar vertebral column, while Type 3 MC were primarily detected at the level of L7-S1.

Discussion

This study demonstrated that MC developed spontaneously in dogs, are common in dogs diagnosed with IVDD, and the type observed varies by breed. Further research is needed to understand the pathogenesis of MC; however, the increased presence of Type 2 MC in CD dogs, similar to what is found in people with disc degeneration, suggests that CD dogs could serve as models for MC in people.

Comparison of Clinical and Radiographic Outcomes Between Transforaminal Endoscopic Lumbar Discectomy and Microdiscectomy: A Follow-up Exceeding 5 Years

OBJECTIVE

To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD).

METHODS

The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients' clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated.

RESULTS

During a mean follow-up of 5.5 years (range, 5-7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio.

CONCLUSION

Both TELD and MD provide generally satisfactory long-term clinical outcomes for patients with LDH. TELD can be used as a reliable alternative to MD with less surgical trauma. Modic type II changes, decreased preoperative intervertebral height, and a high body mass index are predictors of a poor prognosis.

MRI characteristics of disc degeneration after condoliase injection in young patients: A consecutive case series

BACKGROUND

Lumbar disc herniation (LDH) results in low back pain due to nerve root compression caused by nucleus pulposus degeneration. Chemonucleolysis of the nucleus pulposus by injection of condoliase is less invasive than surgery, but may cause disc degeneration. The purpose of the study was to examine outcomes of condoliase injection in patients in their teens and twenties using Pfirrmann criteria on MRI.

METHODS

A single-center retrospective study was performed in 26 consecutive patients (19 men, 7 women) who underwent condoliase injection (1 mL, 1.25 U/mL) for LDH and had MRI scans at 3 and 6 months. Cases with and without an increase in Pfirrmann grade at 3 months post-injection were included in groups D (disc degeneration, n = 16) and N (no degeneration, n = 10). Pain was measured on a visual analogue scale (VAS). MRI findings were evaluated using the % change in disc height index (ΔDHI).

RESULTS

The mean age of the patients was 21.1 ± 4.1 years and 12 were <20 years old. At baseline, 4, 21 and 1 were in Pfirrmann grades II, III and IV. In group D, no case had a further increase in Pfirrmann grade from 3 to 6 months. Pain significantly decreased in both groups. There were no adverse events. MRI showed a significant decrease in ΔDHI from 100% pre-injection to 89.4 ± 9.7% at 3 months in all cases (p < 0.05). There was a significant recovery in ΔDHI in group D from 3 to 6 months (85.4 ± 9.3% vs. 86.7 ± 9.1%, p < 0.05).

CONCLUSIONS

These results suggest that chemonucleolysis with condoliase is effective and safe for LDH in young patients. Progression of Pfirrmann criteria at 3 months post-injection occurred in 61.5% of cases, but disc degeneration showed recovery in these patients. A longer-term study of the clinical symptoms related to these changes is required.

Induction of cervical disc degeneration and discogenic pain by low concentration Propionibacterium acnes infection: an in vivo animal study

BACKGROUND

Although cervical intervertebral disc (IVD) degeneration is closely associated with neck pain, its cause remains unclear. In this study, an animal model of cervical disc degeneration and discogenic neck pain induced by a low concentration of Propionibacterium acnes (P. acnes-L) is investigated to explore the possible mechanisms of cervical discogenic pain.

METHODS

Cervical IVD degeneration and discitis was induced in 8-week-old male rats in C3-C6 IVDs through the anterior intervertebral puncture with intradiscal injections of low and high concentrations of P. acnes (P. acnes-L, n = 20 and P. acnes-H, n = 15) or Staphylococcus aureus (S. aureus, n = 15), compared to control (injection with PBS, n = 20). The structural changes in the cervical IVD using micro-CT, histological evaluation, and gene expression assays after MRI scans at 2 and 6 weeks post-modeling. The P. acnes-L induced IVD degeneration model was assessed for cervical spine MRI, histological degeneration, pain-like behaviors (guarding behavior and forepaw von Frey), nerve fiber growth in the IVD endplate region, and DRG TNF-α and CGRP.

RESULTS

IVD injection with P. acnes-L induced IVD degeneration with decreased IVD height and MRI T2 values. IVD injection with P. acnes-H and S. aureus both lead to discitis-like changes on T2-weighted MRI, trabecular bone remodeling on micro-CT, and osseous fusion after damage in the cartilage endplate adjacent to the injected IVD. Eventually, rats in the P. acnes-L group exhibited significant nociceptive hypersensitivity, nerve fiber ingrowth was observed in the IVD endplate region, inflammatory activity in the DRG was significantly increased compared to the control group, and the expression of the pain neurotransmitter CGRP was significantly upregulated.

CONCLUSION

P. acnes-L was validated to induce cervical IVD degeneration and discogenic pain phenotype, while P. acnes-H induced was identified to resemble septic discitis comparable to those caused by S. aureus infection.

Preclinical Animal Study and Pilot Clinical Trial of Using Enriched Peripheral Blood-Derived Mononuclear Cells for Intervertebral Disc Degeneration

Low back pain (LBP) is a leading cause of long-term disability globally. Intervertebral disk degeneration (IVDD) is mainly responsible for discogenic pain in LBP-affected young patients. There is no effective therapy to reverse disease severity and IVDD progression. This study investigates the effect of human peripheral blood-derived mononuclear cells (PBMCs) on pain relief and life quality improvement in IVDD patients. The enriched monocytes of the PBMCs could differentiate into CD14 and CD206 double-positive M2 macrophages in vitro. Preclinical evidence in rats showed that the transplanted PBMCs exhibited anti-inflammatory and moderate tissue-repair effects on controlling IVDD progress in the rat model. The PBMCs significantly steered the aggrecan and type II collagen expressions and attenuated the pro-inflammatory cytokines in the affected disk. Based on the animal results, 36 patients with chronic low back pain (CLBP) were included in clinical trials. The control group was conservative care only, and the experimental group was platelet-rich plasma (PRP) and PBMCs intradiscal injections. We first confirmed the single lumbar disk causing the discogenic pain by provocative discography or magnetic resonance imaging (MRI). Discogenic LBP participants received one intradiscal injection of autologous PBMCs and followed for 6 months. Our clinical trial showed that patients' LBP and disability were significantly ameliorated after the PBMCs transplantation rather than PRP. These preclinical and pilot clinical studies indicate that intradiscal injection of the enriched PBMCs might be a feasible and potential cell therapy to control pain and disability in IVDD patients.

The influence of geometry on intervertebral disc stiffness

Geometry plays an important role in intervertebral disc (IVD) mechanics. Previous computational studies have found a link between IVD geometry and stiffness. However, few experimental studies have investigated this link, possibly due to difficulties in non-destructively quantifying internal geometric features. Recent advances in ultra-high resolution MRI provides the opportunity to visualise IVD features in unprecedented detail. This study aimed to quantify 3D human IVD geometries using 9.4 T MRIs and to investigate correlations between geometric variations and IVD stiffness. Thirty human lumbar motion segments (fourteen non-degenerate and sixteen degenerate) were scanned using a 9.4 T MRI and geometric parameters were measured. A 1kN compressive load was applied to each motion segment and stiffness was calculated. Degeneration caused a reduction (p < 0.05) in IVD height, a decreased nucleus-annulus area ratio, and a 1.6 ± 3.0 mm inward collapse of the inner annulus. The IVD height, anteroposterior (AP) width, lateral width, cross-sectional area, nucleus-annulus boundary curvature, and nucleus-annulus area ratio had a significant (p < 0.05) influence on IVD stiffness. Linear relationships (p < 0.05, r > 0.47) were observed between these geometric features and IVD compressive stiffness and a multivariate regression model was generated to enable stiffness to be predicted from features observable on clinical imaging (stiffness, N/mm = 6062 - (61.2 × AP width, mm) - (169.2 × IVD height, mm)). This study advances our understanding of disc structure-function relationships and how these change with degeneration, which can be used to both generate and validate more realistic computational models.

Relation of lumbar intervertebral disc height and severity of disc degeneration based on Pfirrmann scores

Background

Disc height (DH) change is considered one of the most critical factors in assessing intervertebral disc degeneration (IVD). Pfirrmann et al. developed a scoring system for disc degeneration evaluation based on changes in DH in magnetic resonance imaging (MRI). While the relationship between DH measurements and Pfirrmann scores for disc degeneration has been explored, the validity of different DH measuring techniques or their connection with disc degeneration is yet uncertain. The present study investigates intra-rater and inter-rater agreement and reliability of different DH measurement methods on MRI and evaluates the relationship between different DH measurement methods and Pfirrmann scores of IVD degeneration, as well as between different Pfirrmann scores and clinical outcomes.

Methods

Adult patients with MRI scans of the lumbar spine were recruited. Eight DH measuring techniques were tested for intra-rater and inter-rater agreement and reliability. Bland and Altman's Limits of Agreement (LOA) was used to evaluate intra-rater and inter-rater agreements. Intra-rater and inter-rater reliability were evaluated using intra-class correlations (ICC) with 95 % confidence intervals (95 % CI). The association between DH and Pfirrmann scores was examined using one-way ANOVA.

Results

Excellent intra-rater reliability was reported for 332 participants on DH (ranging from 0.912 (0.901, 0.923) to 0.973 (0.964, 0.981) and from 0.902 (0.892, 0.915) to 0.975 (0.962, 0.985) by two independent raters). All measuring methods had high intra-rater agreement, except for methods 4 and 5. All methods had good-to-excellent of inter-rater reliability on DH (ICCs ranging from 0.812 (0.795, 0.828) to 0.995 (0.994, 0.995)) except for the posterior disc material length of method 5 (ICC 0.740 (0.718, 0.761)). Methods 1 to 6 for evaluating DH in patients with spondylolisthesis had poor inter-rater reliability. The IVD levels with grades IV and V in Pfirrmann scores had significantly lower DH than the IVD levels with grades I to III in Pfirrmann scores. IVD levels with grades IV and V in Pfirrmann scores had significantly higher VAS and ODI than IVD levels with grades I in Pfirrmann scores.

Conclusion

A good-to-excellent intra-rater and inter-rater reliability was achieved on most DH measuring methods on MRI following a standardized and structured protocol. However, small anatomical structures and different tissue borders could influence measurements. Additionally, DH can differentiate between grade IV and V Pfirrmann scores, and severe IVD degeneration (IV and V Pfirrmann) is linked to clinical outcomes.

Development of normalized quantitative measures of lumbar disc degeneration

Background

Lumbar disc degeneration (DD) is widely regarded as a likely contributor to low back pain (LBP), but the association between DD and LBP is relatively weak. No known studies have normalized quantitative measures of DD severity relative to multiple variables such as age, height, and disc level. This study developed normalized quantitative measures (z-scores) of disc signal intensity (DSI) and disc height (DH) to rate relative severity of DD.

Methods

Raw (unnormalized) quantitative measures of DSI and DH alongside potential normalization variables were acquired from MRI scans and clinical data of 76 patients. The associations between the raw quantitative measures and potential normalization variables were investigated to develop the normalized quantitative measures (z-scores) of DSI and DH. Construct validity was assessed by comparing the normalized measures to an experienced radiologist's subjective measures of relative severity of DSI and DH loss.

Results

CSF signal intensity, age, and disc level were significantly associated with raw DSI (R 2 = 0.06, 0.25, and 0.09, respectively). Lumbar height and disc level were significantly associated with raw DH (R 2 = 0.13 and 0.31). Normalizing DSI and DH by these variables resulted in stronger relationships (R 2 = 0.39 and 0.37) than raw DSI and DH (R 2 = 0.24 and 0.31) with the radiologist's subjective measures. Normalized DSI and DH were both normally distributed (p = 0.32 and 0.12).

Conclusions

Construct validity and the distributions suggested that normalized quantitative measures of DSI and DH are better than existing measures of DSI and DH at rating relative DD severity. Determining whether normalized quantitative measures are more predictive of clinical outcomes is important future research.

Association between height loss and mortality in the general population

Height loss is caused by osteoporosis, vertebral fractures, disc reduction, postural changes, and kyphosis. Marked long-term height loss is reportedly associated with cardiovascular disease and mortality in the elderly. The present study investigated the relationship between short-term height loss and the risk of mortality using the longitudinal cohort data of the Japan Specific Health Checkup Study (J-SHC). Included individuals were aged 40 years or older and received periodic health checkups in 2008 and 2010. The exposure of interest was height loss over the 2 years, and the outcome was all-cause mortality over subsequent follow up. Cox proportional hazard models were used to examine the association between height loss and all-cause mortality. Of the 222,392 individuals (88,285 men, 134,107 women) included in this study, 1436 died during the observation period (mean 4.8 ± 1.1 years). The subjects were divided into two groups based on a cut-off value of height loss of 0.5 cm over 2 years. The adjusted hazard ratio (95% confidence interval) was 1.26 (1.13-1.41) for exposure to height loss ≥ 0.5 cm compared to height loss < 0.5 cm. Height loss ≥ 0.5 cm correlated significantly with an increased risk of mortality compared to height loss < 0.5 cm in both men and women. Even a small decrease in height over 2 years was associated with the risk of all-cause mortality and might be a helpful marker for stratifying mortality risk.

Comparison of the biomechanical effects of lumbar disc degeneration on normal patients and osteoporotic patients: A finite element analysis

BACKGROUND

Some older patients who suffered from both conditions (disc degeneration and osteoporosis) have higher surgical risks and longer postoperative recovery times. Understanding the relation between disc degeneration and osteoporosis is fundamental to know the mechanisms of orthopedic disorders and improve clinical treatment. However, there is a lack of finite element (FE) studies to predict the combined effects of disc degeneration and osteoporosis. So the aim of the present study is to explore the differences of biomechanical effects of lumbar disc degeneration on normal patients and osteoporotic patients.

METHODS

A normal lumbar spine finite element model (FEM) was developed based on the geometric information of a healthy male subject (age 35 years; height 178 cm; weight 65 kg). This normal lumbar spine FEM was modified to build three lumbar spine degeneration models simulating mild, moderate and severe grades of disc degeneration at the L4-L5 segment. Then the degenerative lumbar spine models for osteoporotic patients were constructed on the basis of the above-mentioned degeneration models. Firstly, the normal model (flexion: 8 Nm; extension: 6 Nm; lateral bending: 6 Nm; torsion: 4 Nm) and degenerative models (10 Nm) were calibrated under pure moment load, respectively. Secondly, under a 400 N follower load, the 7.5 Nm moments of different directions were applied on all models to simulate different motion postures. Finally, under the above loading conditions, we calculated and analyzed the range of motion (ROM), Mises stress in cortical (MSC1), Mises stress in endplate (MSE), Mises stress in cancellous (MSC2), and Mises stress in post (MSP).

RESULTS

Compared with disc degeneration patients without osteoporosis, the ROM, MSC1, and MSE of osteoporosis patients with various disc degeneration decreased in all postures, while the MSC2 and MSP increased. With increase in the degree of disc degeneration, the reduction proportions of ROM and MSE in osteoporotic patients gradually increased, while the reduction percentages in MSC1 of osteoporotic patients gradually decreased. The increase percentages of MSC2 in osteoporotic patients gradually increased. Given the progressive changes of disc degeneration, the changes in MSP in osteoporosis patients were uneven.

CONCLUSION

In summary, the effect of disc degeneration on flexibility in the two kinds of patients (osteoporosis and non-osteoporosis patients) was nearly same. By comparing the remaining biomechanical parameters (MSC1, MSE, MSC2, and MSP), we found that degenerated intervertebral discs caused changes in loading patterns of osteoporosis patients. Disc degeneration reduced the Mises stress in the cortical and endplate, which increased the Mises stress in the cancellous and post. That is to say, in order to cope with the changes in bone stresses caused by disc degeneration and osteoporosis, clinicians should be more careful in choosing the surgical option for osteoporotic patients with disc degeneration.

Radiographic risk factors for degenerative lumbar spondylolisthesis: A comparison with healthy control subjects

Objective

To evaluate the radiologic parameters of degenerative lumbar spondylolisthesis (DLS) and determine the radiographic risk factors for DLS by making comparisons with healthy control subjects.

Methods

Seventy-five patients with L4/5 DLS (Meyerding grade I) and 53 healthy control subjects were analyzed. The L1-S1 disc height index (DHI), L4/5 facet joint angle (FJA), and relative cross-sectional area (RCSA) of paravertebral muscles were measured in both groups. The initial L4/5 DHI (iDHI) before the onset of DLS were estimated based on the L3/4 DHI of the DLS group and DHI of the control group. The sagittal parameters of DLS were also included in this study.

Results

The DHI of L4/5 was lower in the DLS group than in the control group (P < 0.05), but the DHI of the L1-L4 segments were much higher than in the control group (P < 0.05). The initial L4/5 DHI and FJA of the DLS group were significantly higher than those of the control group (P < 0.05). The RCSA of the paravertebral muscles were smaller in the DLS group than in the control group (P < 0.05). Binary logistic regression analysis showed that iDHI, FJA, and RCSA of the total paraspinal muscles were risk factors for DLS. The cutoff values for iDHI, FJA, and RCSA were 0.504, 56.968°, and 1.991 respectively. The iDHI was associated with lumbar lordosis (LL), while L4/5 DHI was associated with the RCSA of the multifidus muscle and psoas major muscle (P < 0.05).

Conclusion

A large initial lumbar disc height, large FJA, and paravertebral muscle atrophy may be risk factors for DLS.

The intervertebral disc during growth: Signal intensity changes on magnetic resonance imaging and their relevance to low back pain

Life-time prevalence of low back pain (LBP) in children and adolescents varies from 7% to 72%. Disc changes on magnetic resonance imaging (MRI) have been reported in up to 44% of children with earliest observations around pre-puberty. In this longitudinal cohort study, our objective was to determine the natural history of disc changes from childhood to early adulthood, and the possible association of these changes to LBP. Healthy 8-year-old schoolchildren were recruited for this longitudinal study consisting of a semi-structured interview, a clinical examination, and an MRI investigation at the age of 8-9 (Y8), 11-12 (Y12) and 18-19 (Y19) years. The interview inquired about LBP without trauma. T2-weighted sagittal MRI of the lumbar spine was acquired. Life-long prevalence of LBP was determined, and the disc signal intensity (SI) at the three lowest lumbar levels was assessed both visually using the Schneiderman classification (Bright-Speckled-Dark), and digitally using the disc to cerebrospinal fluid -SI ratio. Possible associations between SI changes and LBP were analyzed. Ninety-four of 208 eligible children were included at Y8 in 1994, 13 and 23 participants were lost to follow-up at Y12 and Y19, respectively. Prevalence of LBP increased after the pubertal growth spurt reaching 54% at Y19. On MRI, 18%, 10% and 38% of participants had disc SI changes at Y8, Y12 and Y19, respectively. No significant associations between self-reported LBP and either qualitative or quantitative disc SI changes were observed at any age. Life-time prevalence of LBP reached 54% by early adulthood. Disc SI changes on MRI traditionally labeled as degenerative were seen earlier than previously reported. Changes in disc SI were not associated with the presence of LBP in childhood, adolescence or early adulthood.

Knowledge Areas and New Trends in Lumbar Disc Herniation Research: Bibliometrics and Knowledge Mapping Analysis

OBJECTIVE

To determine the coalitions and impact of authors, countries, institutions, and journals, evaluate the knowledge base, find the hotspot trends, and identify the emerging topics in lumbar disc herniation (LDH).

METHOD

The articles related to LDH were obtained from the Web of Science Core Collection on August 21, 2021. Two scientometric software (CiteSpace 5.8.R.1 and VOSviewer 1.6.17) were used to perform bibliometric and knowledge-map analysis.

RESULTS

From the set parameters, 4642 articles were included in the literature. Although the total number of publications fluctuated between 2001 and 2020, a general trend toward increase was observed. Respectively, the most productive country and institution in the field were the United States and Wooridul Spine Hospital. The most active and cited authors were Lee and Weinstein. Spine was the most impactful and cited journal. Weinstein (JAMA 296:2441-2450, 2006) had the highest number of co-citations and Weinstein(N Engl J Med 358:794-810, 2008) had the highest number of citations. The keyword "low back pain" was ranked first for frequency and total link strength, whereas "risk factor" was ranked first for centrality. Topics including pathogenesis (disc herniation), examination methods (MRI), treatment methods (non-surgical treatment, surgical treatment), surgical options (laminectomy, discectomy), clinical observations (double-blind, efficacy, outcome, learning curve), and evaluation of efficacy (meta-analysis) of LDH have been the focus of leading-edge research in 2001-2020.

CONCLUSION

Using bibliometric methods, this study mapped the knowledge map of LDH research in the past 20 years. The study identifies existing trends to provide a framework for further research.

Degenerative Lumbar Spine Disease: Imaging and Biomechanics

Chronic low back pain (CLBP) is one of the most common diagnoses encountered when considering years lived with disability. The degenerative changes of the lumbar spine include a wide spectrum of morphological modifications visible on imaging, some of them often asymptomatic or not consistent with symptoms. Phenotyping by considering both clinical and imaging biomarkers can improve the management of CLBP. Depending on the clinical presentation, imaging helps determine the most likely anatomical nociceptive source, thereby enhancing the therapeutic approach by targeting a specific lesion. Three pathologic conditions with an approach based on our experience can be described: (1) pure painful syndromes related to single nociceptive sources (e.g., disk pain, active disk pain, and facet joint osteoarthritis pain), (2) multifactorial painful syndromes, representing a combination of several nociceptive sources (such as lumbar spinal stenosis pain, foraminal stenosis pain, and instability pain), and (3) nonspecific CLBP, often explained by postural (muscular) syndromes.

Radiographic evaluation of lumbar intervertebral disc height index: An intra and inter-rater agreement and reliability study

PURPOSE

To evaluate intra- and inter-rater agreement and reliability of seven reported disc height index (DHI) measurement methods on standing lateral X-ray of lumbar spine.

METHODS

The adult patients who had standing lateral X-ray of lumbar spine were recruited. Seven methods were used to measure DHI of each lumbar intervertebral disc level, including a ratio of sum of anterior and posterior disc height (DH) to disc diameter (Method 1), a ratio of middle DH to mid-vertebral body height (Method 2), a ratio of middle DH to disc diameter (Method 3), a ratio of the mean of anterior, middle, and posterior DH to the sagittal diameter of the proximal vertebral body (Method 4), a ratio of DH to vertebral height which cross the centre of adjacent vertebral bodies (Method 5), a ratio of the mean of anterior, middle, and posterior DH to the mean of proximal and distal vertebral body height (Method 6), and a ratio of the sum of anterior and posterior DH to the sum of superior and inferior disc depth (Method 7). Two raters conducted the measurements (one medical student (SS) and the other an experienced spine surgeon (XC)). Bland and Altmańs Limits of Agreement (LOA) with standard difference were calculated to examine intra- and inter-rater agreements between two out of seven methods for DHI. Intra-class correlations (ICC) with 95% confidence intervals were calculated to assess intra- and inter-rater reliability.

RESULTS

The intra-rater reliability in DHI measurements for 288 participants were ICCs from 0.807 (0.794, 0.812) to 0.922 (0.913, 0.946) by rater 1 (SS) and from 0.827 (0.802, 0.841) to 0.918 (0.806, 0.823) by rater 2 (XC). Method 2, 3, and 5 on all segmental levels had bias (95 % CI does not include zero) or/and out of the acceptable cut-off proportion (>50 %). A total of 609 outliers in 9174 segmental levels' LOA range. Inter-rater reliability was good-to-excellent in all but method 2 (0.736 (0.712, 0.759)) and method 5 (0.634 (0.598, 0.667)). ICCs of related lines to good-to-excellent reliability methods was excellent in all but only indirect lines in method 1 and 4 (ICCs lie in the range from 0.8 to 0.9).

CONCLUSION

Following a structured protocol, intra- and inter-rater reliability was good-to-excellent for most DHI measurement methods on X-ray. However, the complicated methods (more indirect lines) and IVD degeneration (nucleus pulposus degeneration and disc herniation) potentially affected the agreement on inter-rater measurements. Method 7 is the best reproducible method to measure disc height index for all intervertebral disc segmental levels with a good-to-excellent intra- and inter-rater reliability and agreement.

Advantages of deep learning with convolutional neural network in detecting disc displacement of the temporomandibular joint in magnetic resonance imaging

This study investigated the usefulness of deep learning-based automatic detection of anterior disc displacement (ADD) from magnetic resonance imaging (MRI) of patients with temporomandibular joint disorder (TMD). Sagittal MRI images of 2520 TMJs were collected from 861 men and 399 women (average age 37.33 ± 18.83 years). A deep learning algorithm with a convolutional neural network was developed. Data augmentation and the Adam optimizer were applied to reduce the risk of overfitting the deep-learning model. The prediction performances were compared between the models and human experts based on areas under the curve (AUCs). The fine-tuning model showed excellent prediction performance (AUC = 0.8775) and acceptable accuracy (approximately 77%). Comparing the AUC values of the from-scratch (0.8269) and freeze models (0.5858) showed lower performances of the other models compared to the fine-tuning model. In Grad-CAM visualizations, the fine-tuning scheme focused more on the TMJ disc when judging ADD, and the sparsity was higher than that of the from-scratch scheme (84.69% vs. 55.61%, p < 0.05). The three fine-tuned ensemble models using different data augmentation techniques showed a prediction accuracy of 83%. Moreover, the AUC values of ADD were higher when patients with TMD were divided by age (0.8549–0.9275) and sex (male: 0.8483, female: 0.9276). While the accuracy of the ensemble model was higher than that of human experts, the difference was not significant (p = 0.1987–0.0671). Learning from pre-trained weights allowed the fine-tuning model to outperform the from-scratch model. Another benefit of the fine-tuning model for diagnosing ADD of TMJ in Grad-CAM analysis was the deactivation of unwanted gradient values to provide clearer visualizations compared to the from-scratch model. The Grad-CAM visualizations also agreed with the model learned through important features in the joint disc area. The accuracy was further improved by an ensemble of three fine-tuning models using diversified data. The main benefits of this model were the higher specificity compared to human experts, which may be useful for preventing true negative cases, and the maintenance of its prediction accuracy across sexes and ages, suggesting a generalized prediction.

In vivo Mouse Intervertebral Disc Degeneration Models and Their Utility as Translational Models of Clinical Discogenic Back Pain: A Comparative Review

Low back pain is a leading cause of disability worldwide and studies have demonstrated intervertebral disc (IVD) degeneration as a major risk factor. While many in vitro models have been developed and used to study IVD pathophysiology and therapeutic strategies, the etiology of IVD degeneration is a complex multifactorial process involving crosstalk of nearby tissues and systemic effects. Thus, the use of appropriate in vivo models is necessary to fully understand the associated molecular, structural, and functional changes and how they relate to pain. Mouse models have been widely adopted due to accessibility and ease of genetic manipulation compared to other animal models. Despite their small size, mice lumbar discs demonstrate significant similarities to the human IVD in terms of geometry, structure, and mechanical properties. While several different mouse models of IVD degeneration exist, greater standardization of the methods for inducing degeneration and the development of a consistent set of output measurements could allow mouse models to become a stronger tool for clinical translation. This article reviews current mouse models of IVD degeneration in the context of clinical translation and highlights a critical set of output measurements for studying disease pathology or screening regenerative therapies with an emphasis on pain phenotyping. First, we summarized and categorized these models into genetic, age-related, and mechanically induced. Then, the outcome parameters assessed in these models are compared including, molecular, cellular, functional/structural, and pain assessments for both evoked and spontaneous pain. These comparisons highlight a set of potential key parameters that can be used to validate the model and inform its utility to screen potential therapies for IVD degeneration and their translation to the human condition. As treatment of symptomatic pain is important, this review provides an emphasis on critical pain-like behavior assessments in mice and explores current behavioral assessments relevant to discogenic back pain. Overall, the specific research question was determined to be essential to identify the relevant model with histological staining, imaging, extracellular matrix composition, mechanics, and pain as critical parameters for assessing degeneration and regenerative strategies.

Novel Methods to Measure Height and Volume in Healthy and Degenerated Lumbar Discs in MRIs: A Reliability Assessment Study

Background: In the regeneration and therapy of degenerated intervertebral discs, the height, volume or categorizing assessments, such as Pfirrmann classification, are used to quantify the discs themselves and the effects of therapy. Here, the question of transferability, in the sense of reliability, of the results arises in the common exchange. Methods: We have investigated two established and a newly developed (9-point measurement), easy to use methods for height measurement and volume measurement on degenerated and healthy lumbar intervertebral discs of 66 patients regarding inter- and intra-observer reliability. Results: In overview, we found very different reliabilities. While the intra-observer reliability showed good to excellent agreement for both healthy and degenerated lumbar discs for the height and volume measurements, the inter-observer reliability was low or moderate in some cases. The 9-point method for height determination consistently showed better reliability for both healthy and degenerated discs, for both intra- and inter-observer reliability, compared to the two established methods. Conclusions: We recommend using the 9-point measurement as the method to communicate lumbar disc height, both for healthy and degenerated discs. Due to the partly low or moderate reliability, significant differences in the measured heights can already occur, which can lead to a worsened comparability.

Comparison of decompression, decompression plus fusion, and decompression plus stabilization: a long-term follow-up of a prospective, randomized study

BACKGROUND CONTEXT

Lumbar canal stenosis due to degenerative lumbar spondylolisthesis is one of the most common indications for lumbar spinal surgery. However, from a long-term perspective, it is still unclear which of these procedures should be performed: decompression, decompression plus fusion, or decompression plus stabilization.

PURPOSE

This study aimed to present the long-term results of a randomized controlled trial of surgery for degenerative spondylolisthesis.

STUDY DESIGN/SETTING

This is a long-term follow-up of a previously reported randomized controlled trial.

PATIENT SAMPLE

Patients aged ≤75 years with single L4/5 level lumbar canal stenosis caused by degenerative lumbar spondylolisthesis were enrolled at two hospitals from May 1, 2003, to April 30, 2012; the final follow-up was on May 20, 2021.

OUTCOME MEASURES

The following data were collected: modified Japanese Orthopedic Association (JOA) score, visual analog scale (VAS) score for lower back pain, leg pain, and numbness, and scores from eight Short-Form 36 (SF-36) subscales preoperatively, 1 year postoperatively, 5 years postoperatively, and at the final follow-up.

METHODS

Patients were randomized to undergo decompression alone, decompression plus fusion, or decompression plus stabilization. The primary outcome measure was the change in VAS for lower back pain with secondary outcomes including the modified JOA score, VAS for leg pain, VAS for leg numbness, eight SF-36 subscale scores, and occurrence of reoperation at the last follow-up.

RESULTS

Among 85 patients who were randomized, 66 responded to the current survey. The mean follow-up period was 12.3 years. The VAS score for low back pain improvement was not significantly different between the decompression and fusion groups at the mean follow-up of 12.3 years. Of the 12 secondary outcomes, 8 showed no significant difference between decompression and fusion, 12 showed no significant difference between decompression and stabilization, and 10 showed no significant difference between fusion and stabilization.

CONCLUSIONS

Although additional instrumentation surgery did not significantly improve low back pain at the mean follow-up of 12.3 years compared with decompression alone, fusion surgery provided clinically meaningful improvements in patient-reported vitality, social functioning, role limitations due to personal or emotional problems, and mental health compared with decompression alone.

TRIAL REGISTRATION

UMIN000028114.

Distribution Patterns of Degeneration of the Lumbar Spine in a Cohort of 200 Patients with an Indication for Lumbar MRI

Lower back pain is one of the most common causes of a reduced quality of life. Magnetic resonance imaging (MRI) is the best suited imaging technique to detect causes of that pain. We retrospectively evaluated the MRIs of the lumbar spine for 200 patients in order to describe the distribution of signs of degeneration with regard to age, sex, and position of the disc affected. The number of spinal segments affected by degeneration increased with age, as did the number of signs of degeneration per segment. In patients aged between 21 and 30, 38.8% of discs were affected, while for patients aged between 51 and 60, 91.6% of discs were affected. There was no statistically significant gender difference. The lower two segments were most commonly affected by degeneration. The most common were structural changes to the discs, which affected 88.4% of patients over 50. Spondylosis was the most common bone-related change, found in 60.4% of patients over the age of 50. A reduction in disc height increases the likelihood of structural changes to the disc and bone-related changes. When investigating risk factors for developing disc-related diseases, the complex disc degeneration patterns described here should be taken into account.

Increased serum CXCL10 levels are associated with clinical severity and radiographic progression in patients with lumbar disc degeneration

BACKGROUND

Lumbar intervertebral degenerative disc disease (IDD) is a multifaceted progressive condition that commonly occurs in conjunction with lumbar disc herniation (LDH). CXCL10 mRNA appears to be increased in both IDD and LHD.

OBJECTIVE

This study was performed to identify the relationship between serum CXCL10 levels and disease severity in patients with IDD.

METHODS

136 IDD patients with low back pain, 127 asymptomatic volunteers and 120 healthy controls were enrolled. Serum CXCL10 protein concentrations were detected using commercial human CXCL10 ELISA Kits. Serum CXCL10 mRNA were examined using qRT-PCR. Clinical severity was assessed using the visual analog scale (VAS) and Oswestry Disability Index(ODI) scores. Radiographic severity was defined using the MRI-based Pfirrmann classification of disc degeneration. Receiver operating characteristic (ROC) curve analysis was used in estimating the correlation between CXCL10 and Pfirrmann grade. The cross-sectional area (CSA) of the lumbar multifidus muscle (LMM) and psoas major (PM) were calculated, and fat infiltration was evaluated by Ropponen-Kjaer criteria.

RESULTS

Serum CXCL10 concentrations were markedly raised in IDD patients with low back pain in contrast to asymptomatic individuals and healthy controls. Serum CXCL10 levels were positively associated with Pfirrmann grade. ROC curve analysis indicated that serum CXCL10 correlated well with Pfirrmann grade. In addition, serum CXCL10 concentrations were significantly higher in IDD patients with LMM and PM degeneration compared with IDD patients without degeneration. Increased CXCL10 levels positively correlated with VAS and ODI scores, as well as decreased CSA and fat filtration of the LMM and PM.

CONCLUSION

Increased serum CXCL10 levels correspond to clinical severity and radiographic progression in IDD patients.

Short-Term Outcome and Predictors of Therapeutic Effects of Intradiscal Condoliase Injection for Patients with Lumbar Disc Herniation

Introduction

Intradiscal chondroitin sulfate ABC endolyase (condoliase) injection for lumbar disc herniation (LDH) is an intermediate between conservative treatment and surgery. This approach can only be performed once in a lifetime; therefore, understanding the factors that determine the indication for the use of condoliase and predict outcomes is important. The aim of this study was to review clinical and imaging findings in patients after intradiscal condoliase injection, and to assess the short-term outcomes and factors associated with therapeutic effects.

Methods

The subjects were 42 patients with LDH who underwent intradiscal condoliase injection. Patients with and without a ≥50% improvement from baseline of leg pain at 3 months after injection were defined as responders and non-responders, respectively. Clinical features and radiological findings were compared between these groups.

Results

Of the 42 patients, 32 (76.2%) were responders and 10 (23.8%) were non-responders. Of 8 patients with a history of discectomy at the same level as LDH, 6 (75.0%) were responders. Non-responders had a significantly longer time from onset to treatment, smaller herniated volume before treatment, lower percentage reduction of herniated mass, and less intervertebral disc degeneration before treatment. There were no significant differences in LDH types (subligamentous extrusion or transligamentous extrusion types), high-intensity area within the herniation, changes in disc height, and region of condoliase injection between the two groups.

Conclusions

Intradiscal condoliase injection had a good short-term therapeutic effect in patients with LDH, including in transligamentous extrusion-type and revision cases as well as subligamentous extrusion-type cases. Administration of intradiscal condoliase injection may be most effective in patients with a larger herniated mass volume before treatment, and least effective in cases with a longer time and less intervertebral disc degeneration before treatment.

Loss of height predicts total and cardiovascular mortality: a cohort study of northern European women

OBJECTIVE

To examine height changes in middle-aged northern European women in relation to overall and cardiovascular mortality.

DESIGN

Population-based cohort studies with longitudinally measured heights and register-based mortality.

SETTING

Sweden and Denmark.

PARTICIPANTS

Population-based samples of 2406 Swedish and Danish women born on selected years in 1908-1952, recruited to baseline examinations at ages 30-60, and re-examined 10-13 years later.

MAIN OUTCOME MEASURE

Total and cardiovascular disease (CVD) specific mortality during 17-19 years of follow-up after last height measure.

RESULTS

For each 1 cm height loss during 10-13 years, the HR (95% CI) for total mortality was 1.14 (1.05 to 1.23) in Swedish women and 1.21 (1.09 to 1.35) in Danish women, independent of key covariates. Low height and high leisure time physical activity at baseline were protective of height loss, independent of age. Considering total mortality, the HR for major height loss, defined as height loss greater than 2 cm, were 1.74 (1.32 to 2.29) in Swedish women and 1.80 (1.27 to 2.54) in Danish women. Pooled analyses indicated that height loss was monotonically associated with an increased mortality, confirming a significant effect above 2 cm height loss. For cause-specific mortality, major height loss was associated with a HR of 2.31 (1.09 to 4.87) for stroke mortality, 2.14 (1.47 to 3.12) for total CVD mortality and 1.71 (1.28 to 2.29) for mortality due to causes other than CVD.

CONCLUSION

Height loss is a marker for excess mortality in northern European women. Specifically the hazard of CVD mortality is increased in women with height loss during middle age, and the results suggest that the strongest cause-specific endpoint may be stroke mortality. The present findings suggest attention to height loss in early and mid-adulthood to identify women at high risk of CVD, and that regular physical activity may prevent early onset height loss.

TNF-α suppresses SHOX2 expression via NF-κB signaling pathway and promotes intervertebral disc degeneration and related pain in a rat model

This study was conducted to verify the relative expression patterns of SHOX2 and its regulation by tumor necrosis factor alpha (TNF-α) during the development of intervertebral disc degeneration (IVDD). A rat disc-degeneration model was subjected to disc puncture (DP) and intradiscal injections with TNF-α to determine the roles of TNF-α and SHOX2 expression in IVDD in vivo. TNF-α and SHOX2 expression patterns in different degenerative rat nucleus pulposus (NP) tissues were measured by immunohistochemistry (IHC). The effects of TNF-α on IVDD were determined by magnetic resonance imaging (MRI) and pain development of wet-dog shakes (WDS) were blinded assessment by pain-behavior testing, respectively. Changes in TNF-α on SHOX2 expression were measured by Western blot analysis and real-time reverse transcription polymerase chain reaction (RT-PCR). The roles of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) in TNF-α-mediated SHOX2 activation were studied using viral transfection, Western blot analysis, and real-time RT-PCR. In vivo, TNF-α accelerated the process of IVDD and suppressed SHOX2 expression; compared to the DP group, WDS was significantly increased in TNF-α intradiscal injection group at 2 to 6 weeks after puncture (P < .05); In NP cells, TNF-α negatively affected the IVDD-associated SHOX2 suppression. While TNF-α promotes IVDD through activation of both MAPK and NF-κB signaling, it seemed that only NF-κB signaling controlled the TNF-α-mediated SHOX2 suppression that is associated with IVDD. The results of this study indicated that TNF-α inhibits SHOX2 expression and has promoted effects on IVDD in the rat model, and these effects might be associated with through NF-κB signaling pathway and promotes IVDD and related pain in a rat model.

Imaging features of the aging spine

Among many degenerative abnormalities commonly found in spine imaging, not all are associated with the patient's symptoms. We aimed to assess features of the standard, asymptomatic aging process of the spine. In this narrative review, we emphasize studies that describe imaging features of the spine in asymptomatic populations of different age groups. Degeneration of the intervertebral discs, bulging, and facet joint arthropathy have been documented in almost 90% of asymptomatic patients over 60 years of age. After the age of 40 years, nearly all patients have anterior and lateral vertebral osteophytes, whereas posterior osteophytes are found in a minority of them. There is a gradual increase in vertebral bone marrow fat composition with age with the acceleration of this process in women after menopause. The prevalence of these findings is common in asymptomatic populations and varies depending on the patient's age. It is essential to differentiate likely natural and age-related findings from pathological abnormalities to make an accurate diagnosis.

Association between spinal alignment and biochemical composition of lumbar intervertebral discs assessed by quantitative magnetic resonance imaging

Background

To evaluate potential associations between spinopelvic parameters and the biochemical composition of lumbar intervertebral discs using quantitative magnetic resonance imaging in asymptomatic young adults.

Methods

Our study group comprised 93 asymptomatic volunteers aged 20-40 years (49 women and 44 men). Lumbar spine T2-weighted images and T2 relaxometry were acquired on a 1.5T MRI scanner. Spinopelvic parameters including sacral slope, pelvic tilt, pelvic incidence, lumbar lordosis, thoracic kyphosis, thoracolumbar alignment, sagittal vertical axis, spinosacral angle, C2 pelvic angle, and T1S1 and L1S1 length were measured on panoramic spine radiographs.

Results

Lumbar lordosis decrease correlates with discrete dehydration of nucleus pulposus at all lumbar levels. Also low values of sacral slope, pelvic tilt, pelvic incidence, thoracic kyphosis and spinosacral angle were associated with decrease of T2 relaxation times on annulus fibrosus.

Conclusions

In conclusion, spinopelvic parameters presented a discrete association with lumbar disc composition and water content.

Growth differentiation factor-6 attenuates inflammatory and pain-related factors and degenerated disc-induced pain behaviors in rat model

Previous studies have indicated that growth differentiation factor 6 (GDF6) is a potential candidate for intervertebral disc (IVD) degeneration (IDD) treatment. Here, we investigated the effect of GDF6 on IDD by examining changes in disc structure and the expression of inflammatory and pain-related factors. A rat posterior disc puncture model of single segments and three consecutive segments was constructed, and GDF6 or phosphate-buffered solution was administered via intradiscal injection 1 or 2 weeks after surgery. Magnetic resonance imaging showed a clear degeneration signal in the punctured disc, which was inhibited by GDF6. Histological staining revealed that GDF6 did not significantly improve the structure of IVDs in rats 8 weeks after puncture surgery, but it had an inhibitory effect on expression of the tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-1β in the IVD. Furthermore, GDF6 was found to protect the morphology and structure of the IVD 32 weeks after surgery. Mechanical and thermal hyperalgesia tests suggested that GDF6 injection can significantly improve mechanical and thermal-stimulated pain behavior in rats and inhibit the expression of inflammatory factors TNF-α and IL-1β and the pain factor calcitonin gene-related peptide in the dorsal root ganglion. A rat protein array test indicated that GDF6 could reduce the expression of cytokines IL-6, intercellular cell adhesion molecule-1, matrix metalloproteinase-13, IL-1β, and TNF-α and increase the expression of tissue inhibitor of metalloproteinases 1, Transforming growth factor-beta 2, IL-10, and resistin in a TNF-α-induced IDD cell model. Thus, our study demonstrates that GDF6 can improve the structure of the IVD, inhibit the expression of inflammatory and pain-related factors, and improve pain behavior in rats. Clinical Significance: To establish further preclinical research and clinical trials, comprehensive data are needed to validate the regenerative properties of GDF6. Ideally, a regenerative agent should also be able to relieve discogenic pain, achieving the best clinical outcomes.

A microstructure-based modeling approach to assess aging-sensitive mechanics of human intervertebral disc

BACKGROUND AND OBJECTIVE

The human body soft tissues are hierarchic structures interacting in a complex manner with the surrounding biochemical environment. The loss of soft tissues functionality with age leads to more vulnerability regarding to the external mechanical loadings and increases the risk of injuries. As a main example of the human body soft tissues, the intervertebral disc mechanical response evolution with age is explored. Although the age-dependence of the intervertebral disc microstructure is a well-known feature, no noticeable age effect on the disc stiffness is evidenced in the in-vitro experimental studies of the literature. So, if the disc intrinsic mechanics remains constant, how to explain the correlation of disc degeneration and disc functionality loss with age.

METHODS

A microstructure-based modeling approach was developed to assess in-silico the aging-sensitive mechanics of human intervertebral disc. The model considers the relationship between stress/volumetric macro-response and microstructure along with effective age effects acting at the lamellar and multi-lamellar scales. The stress-stretch and transversal responses of the different disc regions were computed for various age groups (13-18, 36, 58, 69 and 82 years old) and their evolution with age was studied.

RESULTS

While matching with in-vitro experimental data, the predicted stiffness was found to increase while passing from adolescent young discs to mature older discs and then to remain almost constant for the rest of life. Important age-related changes in the disc transversal behavior were also predicted affecting the flexibility of the disc, changing its volumetric behavior, and modifying its dimensions.

CONCLUSION

The developed approach was found able to bring new conclusions about age-dependent mechanical properties including regional dependency. The disc mechanics in terms of rigidity, radial and axial transversal responses were found to alter going from adolescent to middle age where the disc reaches a certain maturity. After reaching maturity, the mechanical properties undergo very slight changes until becoming almost constant with age.

Sagittal alignment based on inflection point and its differences according to age groups

PURPOSE

We have always used the standard anatomical landmark vertebrae to measure the sagittal alignment. Instead, scoliosis has been evaluated by the end vertebrae in the coronal plane. There have been clinical studies to investigate sagittal alignment on the end vertebrae of inflection points (IPs). The purpose is to determine sagittal alignment based on IPs and to elucidate the changes while considering age groups.

METHODS

We identified the most titled vertebrae in the sagittal plane to define the end vertebrae of S1, thoracolumbar and cervicothoracic IPs and to measure the Cobb angles of sacral slope, functional lumbar, thoracic, cervical segment between them, and the McGregor's line, and the IP distances from the C2 plumb line to the point bisecting the upper end plate of the IPs, in addition to S1.

RESULTS

The most common thoracolumbar and cervicothoracic IPs were L2 and T1, respectively. However, the next most common cervicothoracic IP changed from T2 in the youngest to C7 in the oldest age group. The sagittal angles decreased at the sacral slope and functional lumbar segment but not the functional thoracic segment and functional cervical segment. Similarly, the distance increased at the C2 sagittal vertical axis (SVA) distance to S1 and thoracolumbar IP distance but not at the cervicothoracic IP distance. There was no difference in the pelvic incidence among age groups.

CONCLUSION

The sagittal Cobb angles based on the IPs decreased at the sacral slope and functional lumbar segment in the older adults. Consequently, the C2 SVA distance to S1 and thoracolumbar IP distance increased.

Spinal Osteoarthritis Is Associated With Stature Loss Independently of Incident Vertebral Fracture in Postmenopausal Women

STUDY DESIGN

Retrospective observational study from the Nagano Cohort Study.

OBJECTIVE

Clarify the association between spinal osteoarthritis and loss of stature in postmenopausal women.

SUMMARY OF BACKGROUND DATA

Loss of stature with aging is known to deteriorate health-related quality of life and has been implicated with increased mortality. Although the association of vertebral fracture with height loss has been well documented, the relationship between stature loss and spinal osteoarthritis remains unclear.

METHODS

We retrospectively investigated Japanese postmenopausal women recruited from the Nagano Cohort Study. The participants were outpatients at a primary care institute in Nagano prefecture, Japan. A total of 977 postmenopausal patients (mean age: 65.8 yr) completed a minimum of 1 year of follow-up, with an average observation period of 7.6 years. Quartile analysis on the prevalence of spinal osteoarthritis and occurrence of incident fracture was performed based on the rate of stature change per year (Δ cm/yr). Multiple regression analysis was also conducted to identify the determinants of stature change.

RESULTS

The lower quartiles of stature change rate (i.e., more rapid stature loss) displayed a significantly higher prevalence of spinal osteoarthritis (P < 0.001) and incident vertebral fracture (P < 0.001). A statistically significant independent negative association for spinal osteoarthritis prevalence with change in stature was revealed by multiple regression analysis after adjusting for confounders including incident vertebral fracture. The partial regression coefficient for spinal osteoarthritis was -0.18 (95% confidence interval -0.33 to -0.03; P = 0.016).

CONCLUSION

This study demonstrated an independent association of spinal osteoarthritis with stature loss in postmenopausal women. Adequate understanding of this relationship and appropriate treatment approaches will help improve health-related quality of life in elderly patients.

LEVEL OF EVIDENCE

3.

Stem Cell Senescence: the Obstacle of the Treatment of Degenerative Disk Disease

Intervertebral disc (IVD) has a pivotal role in the maintenance of flexible motion. IVD degeneration is one of the primary causes of low back pain and disability, which seriously influences patients' health, and increases the family and social economic burden. Recently, stem cell therapy has been proven to be more effective on IVD degeneration disease. However, stem cell senescence is the limiting factor in the IVD degeneration treatment. Senescent stem cells have a negative effect on the self-repair on IVD degeneration. In this review, we delineate that the factors such as telomerase shortening, DNA damage, oxidative stress, microenvironment and exosomes will induce stem cell aging. Recent studies tried to delay the aging of stem cells by regulating the expression of aging-related genes and proteins, changing the activity of telomerase, improving the survival microenvironment of stem cells and drug treatment. Understanding the mechanism of stem cell aging and exploring new approaches to delay or reverse stem cell aging asks for research on the repair of the degenerated disc.

Lactate Efflux From Intervertebral Disc Cells Is Required for Maintenance of Spine Health

Maintenance of glycolytic metabolism is postulated to be required for health of the spinal column. In the hypoxic tissues of the intervertebral disc and glycolytic cells of vertebral bone, glucose is metabolized into pyruvate for ATP generation and reduced to lactate to sustain redox balance. The rise in intracellular H⁺ /lactate concentrations are balanced by plasma-membrane monocarboxylate transporters (MCTs). Using MCT4 null mice and human tissue samples, complemented with genetic and metabolic approaches, we determine that H⁺ /lactate efflux is critical for maintenance of disc and vertebral bone health. Mechanistically, MCT4 maintains glycolytic and tricarboxylic acid (TCA) cycle flux and intracellular pH homeostasis in the nucleus pulposus compartment of the disc, where hypoxia-inducible factor 1α (HIF-1α) directly activates an intronic enhancer in SLC16A3. Ultimately, our results provide support for research into lactate as a diagnostic biomarker for chronic, painful, disc degeneration. © 2019 American Society for Bone and Mineral Research.

Long-term results for total lumbar facet joint replacement in the management of lumbar degenerative spondylolisthesis

OBJECTIVE

The authors evaluated the long-term clinical outcome of a total posterior arthroplasty system in the surgical treatment of lumbar spinal stenosis with degenerative spondylolisthesis.

METHODS

Between June 2006 and July 2007, 10 patients with neurogenic claudication due to spinal stenosis and single-level degenerative spondylolisthesis were enrolled in a nonrandomized prospective clinical study. The patients were evaluated with radiographs and MRI scans, the visual analog scale (VAS) for back and leg pain, the Oswestry Disability Index (ODI), and the SF-36 health survey preoperatively and at 6 weeks, 3 months, 6 months, 1 year, 2 years, 3 years, 7 years, and 11 years postoperatively.

RESULTS

The mean VAS score for leg pain dropped from 83.5 before surgery to 13 at 6 weeks and 17 at 11 years after surgery. The mean VAS score for back pain dropped from 56.2 preoperatively to 12.5 at 6 weeks and 14 at 11 years after surgery. The mean ODI score decreased from 49.1 preoperatively to 13.5 at 6 weeks and 16 at 11 years after surgery. MRI at 11 years demonstrated stenosis adjacent to the stabilized segment in one patient. This patient was not symptomatic. The authors did not find evidence of progression of the spondylolisthesis in any of the cases. In one patient, conversion to posterolateral fusion was performed due to an early device malfunction.

CONCLUSIONS

The results of this 11-year follow-up study demonstrate that, in patients with spinal stenosis and degenerative spondylolisthesis, decompression and posterior arthroplasty maintain clinical improvement and radiological stability.

Descriptive Analysis of an Interdisciplinary Musculoskeletal Program

BACKGROUND

Interdisciplinary musculoskeletal programs address comorbidities confounding musculoskeletal conditions and serve as an alternative to the single provider model.

OBJECTIVE

Descriptive analysis of an interdisciplinary musculoskeletal program.

DESIGN

Retrospective descriptive analysis of patients enrolled in an interdisciplinary musculoskeletal program. Retrospective subanalysis: cohort of patients enrolled in interdisciplinary program with low back pain compared to historical cohort of patients in a single provider clinic.

SETTING

Academic interdisciplinary musculoskeletal health program.

PATIENTS

Patients referred to program with at least one follow-up visit over a 2-year period.

INTERVENTIONS

Interdisciplinary musculoskeletal program involving physiatry, pain anesthesia, nutrition, psychology, rheumatology, sleep medicine, nursing, and physical therapy.

MAIN OUTCOME MEASUREMENTS

Patient Specific Functional Scale (PSFS), Oswestry Low Back Disability Index (ODI), number of magnetic resonance imaging (MRI) scans, computed tomography (CT) scans, opioid prescriptions; Press Ganey scores.

RESULTS

One hundred and seventy-three patients were enrolled and had at least one follow-up visit. Twenty-four percent of patients with any musculoskeletal complaint demonstrated clinically significant improvements in total PSFS. Mean improvement in PSFS was + 0.864 (SD 1.94), which was a statistically significant improvement (P = .0005), but not clinically significant. Magnetic resonance imaging was ordered for 5% of patients, and no computed tomography scans were ordered. Six percent of patients received opioid prescriptions. Press Ganey scores: 96% responded favorably in regard to physician communication quality, 86% of patients responded favorably for access to care, and 78% responded favorably for care coordination. 27.8% of patients with low back pain in the interdisciplinary program achieved a significant decrease in their ODI, compared to 26.6% in the single provider clinic (P = .87).

CONCLUSIONS

Interdisciplinary musculoskeletal programs are a promising model to improve the functioning of patients with musculoskeletal pain and decrease downstream utilization. These programs may be more appropriate for patients at higher risk of developing chronic pain.

Longitudinal changes in bone mineral density, bone mineral content and bone area at the lumbar spine and hip in postmenopausal women, and the influence of abdominal aortic calcification

Longitudinal studies often report that spine bone mineral density (BMD), measured by DXA, is stable in older adults, which has been attributed to osteophyte development and the presence of aortic calcification. A decline in projected spine area as a result of loss of intervertebral disc height might also contribute to higher BMD. We utilised data from 297 postmenopausal women (mean 73 years) who had DXA measurements of the lumbar spine, total hip and femoral neck 5 years apart, and abdominal aortic calcification scoring from vertebral morphometry. BMD declined by -4.4% at the total hip and -3.9% at the femoral neck (p < 0.001), but did not change at the spine (-0.5%, p = 0.12). In contrast, bone mineral content (BMC) declined by -4.0% at the total hip, -2.5% at the femoral neck and -1.7% at the spine (all p < 0.001). Bone area increased by 0.5% at the hip and 1.6% at the femoral neck but declined by -1.2% at the spine (all p < 0.001). 43% of the cohort had abdominal aortic calcification (AAC) present at baseline. The presence of AAC at baseline was not related to changes in BMD or BMC at the total hip or femoral neck, nor to BMD at the spine. However, women with AAC present had a smaller loss of BMC at the spine than those without (-0.8% versus -2.4%, p = 0.03). AAC score increased more over 5 years among those with AAC at baseline than those without (0.28 versus 0.16, p = 0.036). Thus, the stability of spine BMD is the result of both a loss of projected bone area (as a result of intervertebral disc changes and/or a decrease in projected area of the vertebral bodies) and the effects of aortic calcification. Future clinical trials should consider assessing changes in spine BMC as a more informative index of spine mineral status.

Morphometric Analysis of Lumbar Intervertebral Disc Height: An Imaging Study

BACKGROUND

Little published data exist regarding normal values of disc height. Current literature relies on plain radiographs making accurate measurements of individual lumbar disc height difficult.

OBJECTIVE

We seek to establish normal values for lumbar intervertebral discs in different age groups using computed tomography scans in healthy individuals.

METHODS

Two hundred forty anonymized abdominal computed tomography scans (131 women) were prospectively collected once institutional review board approval was obtained. Individuals with spinal pathologies were excluded. Disc height measurements were obtained at the anterior edge, center, and posterior edge of each vertebra in the midsagittal plane, averaged, and compared against age and sex.

RESULTS

Average age was 45 (14-83) years for women and 48 (14-89) years for men. Average lumbar disc height was 5.6 ± 1.1 mm for men and 4.8 ± 0.8 mm for women at T12/L1, 6.9 ± 1.3 mm for men and 5.8 ± 0.9 mm for women at L1/2, 8.1 ± 1.4 mm for men and 6.9 ± 1.1 mm for women at L2/3, 8.7 ± 1.5 mm for men and 7.6 ± 1.2 mm for women at L3/4, 9.2 ± 1.6 mm for men and 8.5 ± 1.6 mm for women at L4/5, and 8.8 ± 1.6 mm for men and 8.6 ± 1.8 mm for women at L5/S1. Disc height was significantly smaller for women than men (P < 0.001), except at L5/S1.

CONCLUSIONS

Variation in disc height is determined much more by sex than age. The maximum height of the interbody space in the adult lumbar spine was at the L4/5 level (8.9 ± 1.7 mm [men], 8.6 ± 1.8 mm [women]). Based on our findings, >10 mm cage height will result in supraphysiologic interbody space restoration and potentially predispose to complications.

Transgenic mice overexpressing human TNF-α experience early onset spontaneous intervertebral disc herniation in the absence of overt degeneration

There is a well-established link between cytokine expression and the progression of intervertebral disc degeneration. Among these cytokines, interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) are the most commonly studied. To investigate whether systemic hTNF-α overexpression affects intervertebral disc health, we studied the spine phenotype of Tg197 mice, a widely used hTNF-α transgenic line. These mice were studied at 12–16 weeks of age using comprehensive histochemical and immunohistological analysis of the spinal motion segment. Micro-CT analysis was performed to quantify vertebral trabecular bone architecture. The Tg197 mice evidenced spontaneous annular tears and herniation with increased vascularity in subchondral bone and significant immune cell infiltration. The full-thickness annular tear without nucleus pulposus (NP) extrusion resulted in neutrophil, macrophage, and mast cell infiltration into the disc, whereas the disc with full-thickness tear and pronounced NP herniation showed additional presence of CD4+ and CD8+ T cells. While the observed defects involved failure of the annular, endplate, and vertebral junction, there were no obvious alterations in the collagen or aggrecan content in the NP and annulus fibrosus or the maturity of collagen fibers in Tg197 mice. Despite elevated systemic inflammation and pronounced loss of trabecular bone in the vertebrae, intact Tg197 discs were healthy and showed an increase in NP cell number. The NP cells in intact discs preserved expression of phenotypic markers: CAIII, Glut1, and Krt19. In conclusion, elevated systemic TNF-α increases the susceptibility of mice to spontaneous disc herniation and possibly radiculopathy, without adversely affecting intact intervertebral disc health.

Biomaterials for intervertebral disc regeneration: Current status and looming challenges

A biomaterial-based strategy is employed to regenerate the degenerated intervertebral disc, which is considered a major generator of neck and back pain. Although encouraging enhancements in the anatomy and kinematics of the degenerative disc have been gained by biomaterials with various formulations in animals, the number of biomaterials tested in humans is rare. At present, most studies that involve the use of newly developed biomaterials focus on regeneration of the degenerative disc, but not pain relief. In this review, we summarise the current state of the art in the field of biomaterial-based regeneration or repair for the nucleus pulposus, annulus fibrosus, and total disc transplantation in animals and humans, and we then provide essential suggestions for the development and clinical translation of biomaterials for disc regeneration. It is important for researchers to consider the commonly neglected issues instead of concentrating solely on biomaterial development and fabrication.

A novel in vivo large animal model of lumbar spinal joint degeneration

BACKGROUND CONTEXT

Degenerative disc disease (DDD) is a common, widespread socioeconomic problem. Appropriate large animal models of DDD are required for improved understanding and to serve as preclinical test beds for therapeutic strategies.

PURPOSE

To evaluate the effects of short and medium duration immobilization on the sheep lumbar intervertebral disc (IVD) and facet joints (FJs), and to establish a large animal model for DDD research.

STUDY DESIGN

An in vivo sheep model evaluating the effect of short- and medium-term immobilization on disc degeneration.

METHODS

Eighteen sheep were equally randomized into three groups: short-term (6-week) immobilization (n=6), medium-term (26-week) immobilization (n=6), and control (no surgery) (n=6). Immobilization of L3-L4 was achieved with pedicle screw and rod implantation, the IVD was kept intact, and the annulus and end plates were not disrupted. The IVD and FJs were assessed with planar radiography, computerized tomography (CT), magnetic resonance imaging (MRI), pure moment biomechanical testing, and histologic analysis.

RESULTS

Disc height was reduced for 6- and 26-week immobilization groups. The MRI and histologic analysis demonstrated significant disc degeneration for both immobilized groups compared with control, but no statistical difference was detected between short- and medium-term duration. Progressive degenerative changes in FJs were observed with micro-CT and histologic end points. Immobilization significantly reduced lateral bending and flexion-extension range of motion.

CONCLUSIONS

The mechanical environment set up by immobilization alone is capable of inducing lumbar disc degeneration at both 6 and 26 weeks in sheep. Longer duration immobilization did not advance disc degeneration process beyond of that found with short duration. The present model produces a degenerative disc with intact annulus and without acute injury, more closely representing the scenario common in human disc degeneration. This provides a suitable large animal in vivo model for the evaluation of the new therapies for disc degeneration. Further studies would do well to examine the effect of remobilization after immobilization in this model.

A novel mouse model of intervertebral disc degeneration shows altered cell fate and matrix homeostasis

Intervertebral disc degeneration and associated low back and neck pain is a ubiquitous health condition that affects millions of people world-wide, and causes high incidence of disability and enormous medical/societal costs. However, lack of appropriate small animal models with spontaneous disease onset has impeded our ability to understand the pathogenetic mechanisms that characterize and drive the degenerative process. We report, for the first time, early onset spontaneous disc degeneration in SM/J mice known for their poor regenerative capacities compared to "super-healer" LG/J mice. In SM/J mice, degenerative process was marked by decreased nucleus pulposus (NP) cellularity and changes in matrix composition at P7, 4, and 8 weeks with increased severity by 17 weeks. Distinctions between NP and annulus fibrosus (AF) or endplate cartilage were lost, and NP and AF of SM/J mice showed higher histological grades. There was increased NP cell death in SM/J mice with decreased phenotypic marker expression. Polarized microscopy and FTIR spectroscopy demonstrated replacement of glycosaminoglycan-rich NP matrix with collagenous fibrous tissue. The levels of ARGxx were increased in, indicating higher aggrecan turnover. Furthermore, an aberrant expression of collagen X and MMP13 was observed in the NP of SM/J mice, along with elevated expression of Col10a1, Ctgf, and Runx2, markers of chondrocyte hypertrophy. Likewise, expression of Enpp1 as well as Alpl was higher, suggesting NP cells of SM/J mice promote dystrophic mineralization. There was also a decrease in several pathways necessary for NP cell survival and function including Wnt and VEGF signaling. Importantly, SM/J discs were stiffer, had decreased height, and poor vertebral bone quality, suggesting compromised motion segment mechanical functionality. Taken together, our results clearly demonstrate that SM/J mouse strain recapitulates many salient features of human disc degeneration, and serves as a novel small animal model.

Condoliase for the Treatment of Lumbar Disc Herniation: A Randomized Controlled Trial

STUDY DESIGN

A randomized, double-blind, placebo-controlled, multicenter phase III clinical trial.

OBJECTIVE

To evaluate the efficacy and safety of chemonucleolysis with condoliase in patients with lumbar disc herniation (LDH).

SUMMARY OF BACKGROUND DATA

Condoliase is a pure mucopolysaccharidase derived from a bacterium, Proteus vulgaris that has high substrate specificity for chondroitin sulfate and hyaluronic acid in the nucleus pulposus of the intervertebral disc.

METHODS

In this study, patients aged 20 to 70 years with unilateral leg pain, positive straight leg raise test, and a contained LDH were recruited in Japan. Patients were treated with a single injection of condoliase (1.25 U) or placebo and were followed for 1 year after administration. The primary endpoint was change in worst leg pain from baseline to week 13. The secondary endpoints included responder rate, and the changes from baseline up to week 52 in the worst leg pain, worst back pain, Oswestry Disability Index, 36-Item Short-Form Health Survey, neurologic examinations, and imaging parameters.

RESULTS

A total of 82 and 81 patients received an injection of condoliase and placebo, respectively. The average changes in worst leg pain from baseline to week 13 (primary endpoint) were -49.5 mm in the condoliase group and -34.3 mm in the placebo group, and the difference of -15.2 mm was significant (95% confidence interval, -24.2 to -6.2; P = 0.001). Significant improvements were observed in the condoliase groups, compared with the placebo group, in most secondary endpoints at 1 year after administration. In the condoliase group, back pain, Modic type 1 change, and decrease in disc height were frequently reported, without any clinically relevant consequences.

CONCLUSION

Condoliase significantly improved symptoms in patients with LDH and was well tolerated. Condoliase is a novel and potent chemonucleolytic drug for the treatment of LDH.

LEVEL OF EVIDENCE

1.

Magnetic resonance morphometry of the adult normal lumbar intervertebral space

PURPOSE

This study aims to: (a) quantify and evaluate normal relationships between neighboring spinal units using MR imaging indices, (b) propose an easy-to-apply-and-reproduce method of estimating the correct amount of distraction when surgically restoring a collapsed intervertebral disc, based on individualized measurements.

METHODS

This is a retrospective cross-sectional MR imaging study of 119 adult subjects, aged 18-54, asymptomatic for low back pain. Each of the examinees should demonstrate two or more consecutive intervertebral discs classified as Pfirrmann grade I or II to be included. We measured and studied the relationships of disc height index, Dabbs index, Farfan index, disc convexity index and mean and posterior disc height per spinal level using multiple regression analysis. All measurements were tested for intra- and interobserver agreement by two raters.

RESULTS

DHI, Dabbs, Farfan, and mean disc height had a statistically significant correlation with the spinal level and age. Our results were highly reproducible, with excellent inter- and intraobserver agreement and reliability between two raters (ICC = 0.992 and 0.994, respectively). Furthermore, we expressed each intervertebral space as a percentage of its adjacent space, introducing the coefficient α factor for every intervertebral space.

CONCLUSIONS

Our results suggest that a normal values' database to refer during preoperative planning of correction of a degenerated intervertebral disc is feasible. Our study offers new anatomical and radiological insight in terms of spinal measurements and their potential correlation with current surgical techniques. A new approach for calculating disc space as an expression of its adjacent disc has been introduced with various potential applications.

A multicenter, randomized, double-blind, dose-finding study of condoliase in patients with lumbar disc herniation

OBJECTIVE

Chemonucleolysis with condoliase has the potential to be a new, less invasive therapeutic option for patients with lumbar disc herniation (LDH). The aim of the present study was to determine the most suitable therapeutic dose of condoliase.

METHODS

Patients between 20 and 70 years of age with unilateral leg pain, positive findings on the straight leg raise test, and LDH were recruited. All eligible patients were randomly assigned to receive condoliase (1.25, 2.5, or 5 U) or placebo. The primary end point was a change in the worst leg pain from preadministration (baseline) to week 13. The secondary end points were changes from baseline in the following items: worst back pain, Oswestry Disability Index (ODI), SF-36, and neurological examination. For pharmacokinetic and pharmacodynamic analyses, plasma condoliase concentrations and serum keratan sulfate concentrations were measured. The safety end points were adverse events (AEs) and radiographic and MRI parameters. Data on leg pain, back pain, abnormal neurological findings, and imaging parameters were collected until week 52.

RESULTS

A total of 194 patients received an injection of condoliase or placebo. The mean change in worst leg pain from baseline to week 13 was −31.7 mm (placebo), −46.7 mm (1.25 U), −41.1 mm (2.5 U), and −47.6 mm (5 U). The differences were significant at week 13 in the 1.25-U group (−14.9 mm; 95% CI −28.4 to −1.4 mm; p = 0.03) and 5-U group (−15.9 mm; 95% CI −29.0 to −2.7 mm; p = 0.01) compared with the placebo group. The dose-response improvement in the worst leg pain at week 13 was not significant (p = 0.14). The decrease in the worst leg pain in all 3 condoliase groups was observed from week 1 through week 52. Regarding the other end points, the worst back pain and results of the straight leg raise test, ODI, and SF-36 showed a tendency for sustained improvement in each of the condoliase groups until week 52. In all patients at all time points, plasma condoliase concentrations were below the detectable limit (< 100 μU/ml). Serum keratan sulfate concentrations significantly increased from baseline to 6 hours and 6 weeks after administration in all 3 condoliase groups. No patient died or developed anaphylaxis or neurological sequelae. Five serious AEs occurred in 5 patients (3 patients in the condoliase groups and 2 patients in the placebo group), resolved, and were considered unrelated to the investigational drug. Severe AEs occurred in 10 patients in the condoliase groups and resolved or improved. In the condoliase groups, back pain was the most frequent AE. Modic type 1 change and decrease in disc height were frequent imaging findings. Dose-response relationships were observed for the incidence of adverse drug reactions and decrease in disc height.

CONCLUSIONS

Condoliase significantly improved clinical symptoms in patients with LDH and was well tolerated. While all 3 doses had similar efficacy, the incidence of adverse drug reactions and decrease in disc height were dose dependent, thereby suggesting that 1.25 U would be the recommended clinical dose of condoliase.

Clinical trial registration no.: NCT00634946 (clinicaltrials.gov)

A cross-sectional study: serum CCL3/MIP-1α levels may reflect lumbar intervertebral disk degeneration in Han Chinese people

Background

The macrophage inflammatory protein-1α (MIP-1α), also named chemokine cytokine ligand 3 (CCL3), has been detected in nucleus pulposus and increased following cytokine stimulation.

Objective

The current study was performed to explore the relationship between serum CCL3/MIP-1α levels with lumbar intervertebral disk degeneration (IDD).

Patients and methods

A total of 132 disk degeneration patients confirmed by magnetic resonance imaging and 126 healthy controls were enrolled in the current study. Radiological evaluation of the IDD was conducted using a 3.0-T magnetic resonance imaging scanner for entire lumbar vertebra region. Degeneration of intervertebral disk was assessed by Schneiderman criteria. Serum CCL3/MIP-1α levels were investigated using a sandwich enzyme-linked immunosorbent assay. The Visual Analog Scale scores and Oswestry Disability Index index were recorded for clinical severity.

Results

Elevated concentrations of CCL3 in serum were found in IDD patients compared with asymptomatic volunteers. The case group included 49 IDD patients with grade 1, 42 with grade 2, and 41 with grade 3. Grade 3 and 2 had significantly higher CCL3 concentrations in serum compared with those with grade 1. The serum CCL3 levels were positively related to the degree of disk degeneration. In addition, the serum CCL3 levels also demonstrated a significant correlation with the clinical severity determined by Visual Analog Scale scores and Oswestry Disability Index index.

Conclusion

Serum CCL3 may serve as a biomarker of IDD.