Older men with severe disc degeneration have more incident vertebral fractures-the prospective MINOS cohort study

Disc degeneration influences the strain magnitude and stress distribution within the adjacent trabecular bone

Introduction

Up to one in five will suffer from osteoporotic vertebral fracture within their lifetime. Accurate fracture prediction poses challenges using bone mineral density (BMD) measures. Trabecular bone strains may be influenced by the underlying intervertebral disc (IVD). Understanding how disc degeneration alters load distribution to the vertebra may demonstrate that supplementing fracture risk tools with IVD metrics could improve predictions. The aim of this study was to assess the influence of IVD degeneration on the stress and strain magnitude and distribution in the trabecular bone of adjacent vertebrae.

Methods

Ten human cadaveric lumbar bi-segment specimens (20 IVDs, 9 degenerated, 11 non-degenerated) were µCT-imaged under 1000N. Digital volume correlation was used to quantify axial, principal, maximum shear, and von Mises strain in the superior and inferior regions of the vertebra. Volumetric BMD from quantitative-CT was used to calculate Young's modulus, which was then registered with the von Mises strain field to calculate internal von Mises stress.

Results

Two bi-segments fractured during mechanical testing, resulting in N = 8 endplate regions per group. Trabecular bone adjacent to degenerated IVDs presented higher maximum principal and shear strains in the anterior region, relative to non-degenerated (peak ε1: 6,020 ± 1,633 µε versus 3,737 ± 1,548 µε, p < 0.01; peak γmax: 6,202 ± 1948 µε versus 3,938 ± 2086 µε, p < 0.01). Von Mises stress distribution was significantly skewed towards the anterior region in the degenerated group only (28.3% ± 10.4%, p < 0.05). Reduced disc height correlated with increased central-region axial compressive strain, decreased central-region BMD, and increased anterior region von Mises stress (all p < 0.05).

Discussion

Disc degeneration may encourage high strains to be experienced within the anterior region of the adjacent bone, owing to changes in load distribution. This study demonstrates the potential of utilising IVD metrics in fracture risk assessment, to inform clinical decision making and preventative treatment.

Percutaneous functional spinal unit cementoplasty versus percutaneous kyphoplasty for severe osteoporotic vertebral compression fracture complicated with endplate-disc complex injury: A retrospective case-control study

BACKGROUND

Severe osteoporotic vertebral compression fracture (SOVCF) is frequently complicated by endplatedisc complex (EDC) injury. While percutaneous kyphoplasty (PKP) can offer rapid analgesia and facilitate early activity, it does not restore vertebral height and may result in intervertebral leakage and untreated EDC injury.

OBJECTIVE

This study aimed to evaluate the clinical outcomes of percutaneous functional spinal unit cementoplasty (PFSUP) for SOVCF complicated by EDC injury and compare its clinical and imaging outcomes with PKP.

METHODS

This was a retrospective case-control study. Patients with SOVCF complicated with EDC injury between January 1, 2018, and December 31, 2019, were recruited and assigned to the PKP group and PFSUP group based on their treatment procedures Back pain was evaluated using the visual analog scale (VAS) and daily life activities were assessed using the Oswestry disability index (ODI). X-rays were employed to observe the presence and location of cement leakage, as well as to measure the sagittal vertical axis (SVA) and local kyphosis angle (LKA). Loss of correction was calculated by subtracting the LKA after surgery from that at the final follow-up visit Subsequent vertebral fracture (SVF) was confirmed using the Genant semi-quantitative method and/or MRI.

RESULTS

A total of 64 patients were included in this study. Among them 41 cases were assigned to the PKP group (28 females, 74.8 years on average), while the remaining 23 cases were assigned to the PFSUP group (15 females, 76.3 years on average). All surgical interventions were successfully completed without major complications. Compared to the PKP group, the PFSUP group had longer operation time (70.28 ± 11.44 vs 44.5 ± 10.12, P< 0.001) higher frequencies of radiation exposure (97.6 ± 19.85 vs 38.6 ± 9.53, P< 0.001), and a lower cement leakage rate (26.1% vs. 41.5%, P< 0.001). One day after surgery and at the final follow-up the PFSUP group had lower VAS and ODI scores, as well as lower LKA and Sva values compared with the PKP group (all P< .001). At the final follow-up visit, the PFSUP group demonstrated a lower loss of correction (4.38 ± 2.71 vs. 10.19 ± 3.41 P< 0.001) and a lower SVF rate compared to the PKP group (21.7% vs. 31.7%, P< 0.001).

CONCLUSION

PFSUP outperformed PKP in alleviating pain restoring and maintaining sagittal balance, and lowering the incidence of cement leakage and SVF for SOVCF with EDC injury However, PFSUP was associated with longer operation time and high radiation exposure frequencies.

The relation of osteoporotic vertebral fractures and spine degeneration on the occurrence of complications: a systematic review

STUDY DESIGN

Systematic review.

PURPOSE

Osteoporotic vertebral fractures (OVFs) and degenerative spine conditions are age-related and associated with higher morbidity and mortality and greater health care costs. The relationship between OVFs and prevalent spine degeneration is rarely reported. The aim of this study was to systematically review current literature on the influence of preexisting degenerative spine conditions in patients with OVFs on the occurrence of complications during and after treatment.

METHODS

A systematic literature review adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed using Web of Science and MEDLINE. We considered English and German articles published from January 1990 to December 2022. The inclusion criteria were patients with OVFs and preexisting spinal degeneration with complications such as subsequent fractures, deformity, implant failure and surgical and general complications. The included studies were controlled trials, cohort studies, and case series.

RESULTS

Ten articles met the inclusion criteria (two prospective studies, seven retrospective studies and one case series). These were divided into two groups: studies on OVFs in patients with coexisting degenerative spine conditions (n = 5) and studies on OVFs following surgical treatment for degenerative spine conditions (n = 5). Three studies reported more complications in patients with OVFs and severe degeneration. One study stated the opposite. One study did not find any correlation. The remaining studies described complications narratively. Subsequent fractures were the most frequent complications.

CONCLUSION

OVFs in patients with preexisting spinal degeneration seem to cause more complications. In addition to subsequent fractures, other complications have rarely been examined. The presence of degenerative changes or undergoing surgical correction may increase the risk of subsequent fractures.

CT based bone mineral density as a predictor of proximal junctional fractures

Background

Proximal junctional fractures (PJFr) can be a catastrophic complication associated with adult spinal deformity surgery. Osteoporosis can be a major risk factor for the cause of PJFr. Recent studies suggest using surrogate computed tomography (CT) scans in place of spinal dual-energy x-ray absorptiometry (DEXA) scores for bone mineral density (BMD). Investigate the feasibility of using preoperative CT based bone mineral density at upper instrumented vertebrae (UIV) and one level proximally (UIV+1) and distally (UIV-1) to predict the possibility of PJFr risk.

Methods

Retrospective two-academic center case-controlled study, reviewed consecutive adult spinal deformity surgeries; included constructs encompassing at least five fusion levels and fusions to pelvis. Examined demographic, surgical, and radiographic data preoperatively, postoperatively, and final follow-up. Formed groups based on type of proximal junctional deformity (PJD): Control (no PJD), proximal junctional kyphosis (PJK) and PJFr. Preoperative CT BMD values measured in Hounsfield units (HU) for sagittal and axial planes at UIV, UIV+1, and UIV-1 and compared between groups.

Results

N=92 patients. Preoperative CT scan BMD values were significantly lower in PJFr vs. control at: UIV+1 in sagittal (p=0.007), axial (p=0.02) planes; UIV sagittal (p=0.04) and axial (p=0.03) planes; and UIV-1 sagittal (p=0.05) plane. Similarly, lower CT scan BMD values noted in PJFr vs. PJK at: UIV+1 in sagittal (p=0.04) and axial (p=0.03) planes. Trend seen with lower CT scan BMD values at UIV+1 level in PJFr vs. PJK in sagittal (p=0.12) and axial (p=0.10) planes. Preoperative global sagittal imbalance measurements significantly lower in control, but comparable between PJK and PJFr.

Conclusions

Higher preoperative global sagittal imbalance with lower preoperative CT BMD values at UIV and UIV+1 vertebral body may increase the risk of proximal junctional fractures after adult spine deformity surgery. Proximal junctional hooks may supplement the pathogenesis. Readers should note the small sample size.

Level of Evidence: 3

Relationship between diffuse idiopathic skeletal hyperostosis and fragility vertebral fracture: a prospective study in older men

OBJECTIVE

To analyse the risk of incident vertebral and non-vertebral fracture in men with DISH.

METHODS

In 782 men ages 50-85 years, DISH was diagnosed using Resnick's criteria. In men followed prospectively for 7.5 years, a radiographic incident vertebral fracture was defined by a decrease of ≥20% or ≥4mm in any vertebral height vs baseline. Self-reported incident non-vertebral fractures were confirmed by medical records.

RESULTS

Men with DISH had higher BMD at the lumbar spine (P < 0.05), but not at other skeletal sites. After adjustment for confounders including disc space narrowing (DSN) and endplate irregularity, the risk of vertebral fracture was higher in men with DISH vs men without DISH [10/164 (6.1%) vs 16/597 (2.7%), P < 0.05; odds ratio (OR) 2.89 (95% CI 1.15, 7.28), P < 0.05]. DISH and low spine BMD were each associated with a higher vertebral fracture risk. The vertebral fracture risk was higher in men who had both DISH and severe DSN. DISH and endplate irregularities (EIs) were each associated with higher vertebral fracture risk. DISH, DSN and EIs define the intervertebral space dysfunction, which was associated with higher vertebral fracture risk [OR 3.99 (95% CI 1.45, 10.98), P < 0.01]. Intervertebral space dysfunction improved the vertebral fracture prediction (ΔAUC = +0.111, P < 0.05), mainly in men with higher spine BMD (>0.9 g/cm2; ΔAUC = +0.189, P < 0.001). DISH was not associated with the risk of non-vertebral fracture.

CONCLUSION

DISH is associated with higher vertebral fracture risk, independently of other risk factors. Assessment of the intervertebral space dysfunction components may improve the vertebral fracture prediction in older men.

The Fate of Proximal Junctional Vertebral Fractures after Long-Segment Spinal Fixation : Are There Predictable Radiologic Characteristics for Revision surgery?

OBJECTIVE

To investigate the radiographic characteristics of the uppermost instrumented vertebrae (UIV) and UIV+1 compression fractures that are predictive of revision surgery following long-segment spinal fixation.

METHODS

A total 27 patients who presented newly developed compression fracture at UIV, UIV+1 after long segment spinal fixation (minimum 5 vertebral bodies, lowest instrumented vertebra of L5 or distal) were reviewed retrospectively. Patients were divided into two groups according to following management : revisional surgery (group A, n=13) and conservative care (group B, n=14). Pre- and postoperative images, and images taken shortly before and after the occurrence of fracture were evaluated for radiologic characteristics.

RESULTS

Despite similar degrees of surgical correction of deformity, the fate of the two groups with proximal junctional compression fractures differed. Immediately after the fracture, the decrement of adjacent disc height in group A (32.3±7.6 mm to 23.7±8.4 mm, Δ=8.5±6.9 mm) was greater than group B (31.0±13.9 mm to 30.1±15.5 mm, Δ=0.9±2.9 mm, p=0.003). Pre-operative magnetic resonance imaging indicated that group A patients have a higher grade of disc degeneration adjacent to fractured vertebrae compared to group B (modified Pfirrmann grade, group A : 6.10±0.99, group B : 4.08±0.90, p=0.004). Binary logistic regression analysis indicated that decrement of disc height was the only associated risk factor for future revision surgery (odds ratio, 1.891; 95% confidence interval, 1.121-3.190; p=0.017).

CONCLUSION

Proximal junctional vertebral compression fractures with greater early-stage decrement of adjacent disc height were associated with increased risk of future neurological deterioration and necessity of revision. The condition of adjacent disc degeneration should be considered regarding severity and revision rate of proximal junctional kyphosis/proximal junction failures.

Vertebral Fractures Associated with Spinal Sagittal Imbalance and Quality of Life in Acromegaly: A Radiographic Study with EOS 2D/3D Technology

INTRODUCTION

Acromegaly is commonly complicated by arthropathy and skeletal fragility with high risk of vertebral fractures (VFs).

OBJECTIVE

This study aimed to assess whether VFs may be associated with sagittal spine deformities, arthropathy, impaired quality of life (QoL), pain, and disability.

METHODS

Thirty-eight patients with acromegaly (median age: 55 years, 20 males) and 38 matched control subjects were evaluated by a low-dose sagittal and coronal planes, X-ray imaging system (EOS®-2D/3D) for morphometric VFs, radiological signs of spine arthropathy, and spine deformities (Cobb thoracic index ≥40°, pelvic incidence minus lumbar lordosis ≥10°, pelvic tilt >20°, and sagittal vertical axis ≥4 cm) determining sagittal spine imbalance. Acromegalic patients were also evaluated by questionnaires for QoL (Acromegaly QoL Questionnaire [AcroQoL] and Short Form-36 [SF-36]) and pain and disability (Western Ontario and McMaster University [WOMAC]).

RESULTS

Acromegalic patients showed higher prevalence of thoracic hyperkyphosis (i.e., Cobb thoracic index ≥40°; p = 0.04) and pelvic tilt >20° (p = 0.02) than control subjects. VFs were found in 34.2% of acromegalic patients (p = 0.003 vs. control subjects), in relationship with higher prevalence of hyperkyphosis (p = 0.03), pelvic tilt >20° (p = 0.04), sagittal vertical axis ≥4 cm (p = 0.03), and moderate/severe subchondral degeneration (p = 0.01). Moreover, patients with VFs had lower AcroQoL general health (p = 0.007) and SF-36 general health (p = 0.002) scores and higher WOMAC pain (p = 0.003) and global (p = 0.009) scores than patients who did not fracture.

CONCLUSIONS

In acromegaly, VFs may be associated with spine deformities and sagittal imbalance, spine arthropathy, impaired QoL, and disability.

Long term prognosis of Scheuermann's disease: The association with fragility fracture - The MINOS cohort

The aim was to assess the association of Scheuermann's disease (SCD) with fracture risk (vertebral, peripheral) and bone mineral density (BMD) in older men. SCD was assessed on the baseline lateral spine radiographs using the Berlin criteria in 766 men aged 50-85. We evaluated the association of SCD and its diagnostic criteria with incident fracture (vertebral over 7.5 years, peripheral over 10 years) and BMD (baseline). SCD prevalence was 25.2%. SCD and its criteria showed inconsistent associations with BMD at different skeletal sites. Eighty-four men had incident fractures. After adjustment for age, weight, spine BMD, prevalent vertebral fractures, prior falls and score of disc space narrowing due to osteoarthritis (DSN-OA), SCD was not associated with vertebral fracture risk. Vertebral endplate irregularities (EI), one of its diagnostic criteria, were associated with higher vertebral fracture risk (OR = 3.26, 95% CI: 1.34-7.94, p < 0.01). Vertebral fracture risk was higher in men with EI and low spine BMD vs. men without these characteristics (OR = 12.84, 95% CI: 3.12-52.83, p < 0.005). EI was associated with higher vertebral fracture risk in men without severe DSN-OA and without prevalent vertebral fractures. Peripheral fracture risk was lower in men with SCD (HR = 0.39, 95% CI: 0.18-0.83, p < 0.02) and EI. Peripheral fracture risk was higher in men without SCD who had low femoral neck BMD vs. men with SCD and normal BMD (HR = 4.68, 95% CI: 1.09-20.03, p < 0.05). In conclusion, EI were associated with high vertebral fracture risk. SCD and EI were associated with lower peripheral fracture risk. The associations of SCD and its criteria with BMD were inconsistent.