Intradiscal vacuum phenomenon and spinal degeneration: a cross-sectional analysis of 219 subjects

Can gas and infection coexist in the intervertebral disc? A retrospective analysis of percutaneously biopsied suspected discitis-osteomyelitis cases

OBJECTIVES

To retrospectively evaluate the correlation between intradiscal gas and infection in patients percutaneously biopsied for suspected discitis-osteomyelitis.

MATERIALS AND METHODS

We retrospectively reviewed all CT-guided discitis-osteomyelitis biopsies performed between 2002 and 2022. Two independent trained musculoskeletal radiologists evaluated for presence of gas on CT and/or MRI within 1 week of the biopsy. Disagreements were resolved by a third musculoskeletal radiologist. CT was considered the gold standard for the detection of intradiscal gas. Pathology, microbiology, and imaging and clinical follow-up were used as the gold standard for presence of infection. Interrater agreement on CT and MRI, sensitivity, and positive predictive value were calculated, using the presence of gas as an indicator (test positive) for "no infection."

RESULTS

There were 284 biopsies in 275 subjects (mean age 58 ± 1.0 (range 4-99) years; 101 (37%) females and 174 (63%) males). Of the biopsies, 12 (4%) were cervical, 80 (28%) were thoracic, 192 (68%) were lumbar, and 200 (70%) were considered true discitis-osteomyelitis based on pathology, imaging, and clinical follow-up. Interrater agreement was excellent for CT (kappa = 0.83) and poor for MRI (kappa =  - 0.021). The presence of gas had a 94% specificity and 76% negative predictive value for the absence of infection.

CONCLUSION

CT is the preferred method for detecting intradiscal gas. The presence of gas means that discitis-osteomyelitis is unlikely. If intradiscal gas is present in the setting of discitis-osteomyelitis, the gas bubbles tend to be smaller and fewer in number.

Natural History of Intradiscal Vacuum Phenomenon and its Role in Advanced Disc Degeneration

STUDY DESIGN

Observational serial computed tomography (CT) analysis of the lumbar spine in a normal-aging population.

OBJECTIVE

To assess the natural history of the intradiscal vacuum phenomenon (IDVP) and its role in disc degeneration.

BACKGROUND

The natural history of disc degeneration is well described but our understanding of the end stage of pathogenesis remains incomplete. Magnetic resonance imaging loses accuracy with advanced degeneration, becoming hyporesonant and indistinct. Cadaveric specimens display adaptive changes in the disc with loss of the hydrostatic capacity of the nucleus, increased intradiscal clefts, and endplate impermeability. IDVP is associated with advanced disc degeneration and CT is the optimal modality to visualize this, yet these insights remain unreported.

PATIENTS AND METHODS

Patients only included historic CT abdomen scans of those over 60 years of age without acute or relevant spinal pathology, with a diagnosis of at least one level with IDVP on the original CT scan, and all of whom had a similar scan >7 years later. A history of clinically significant back pain was also recorded.

RESULTS

CT scans included 360 levels in 29 males and 31 females (mean: 68.9 y), displaying 82 levels of IDVP, with a second scan included after a mean of 10.3 years. Most levels displayed the same level of severity (persisted, 45) compared with where some progressed (26), regressed (8), and fused (3; P < 0.01). There was also an increased incidence, 37/60 (62%) of developing IDVP at another level. Disc heights were reduced with increased severity of IDVP. A record of back pain was evident in 31/60 patients, which was not significantly worse in those with worsening severity or additional level involvement over the study period.

CONCLUSION

As disc degeneration advances, the associated IDVP persists in most cases, displaying a plateauing of severity over long periods, but rarely with progression to autofusion.

Intradiscal vacuum phenomenon matches lumbar spine degeneration patterns in an ageing population

PURPOSE

Intra-Discal Vacuum phenomenon (IDVP) is well-recognised, yet poorly visualised and poorly understood radiological finding in disc degeneration, particularly with regard to its role in spinal alignment. CT analysis of the lumbar spine in an aging population aims to identify patterns associated with IDVP including lumbopelvic morphology and associated spinal diagnoses.

METHODS

An analysis was performed of an over-60s population sample of 2020 unrelated abdominal CT scans, without acute spinal presentations. Spinal analysis included sagittal lumbopelvic reconstructions to assess for IDVP and pelvic incidence (PI). Subjects with degenerative pathologies, including previous vertebral fractures, auto-fusion, transitional vertebrae, and listhesis, were also selected out and analysed separately.

RESULTS

The prevalence of lumbar spine IDVP was 50.3% (955/1898) and increased with age (125 exclusions). This increased in severity towards the lumbosacral junction (L1L2 8.3%, L2L3 10.9%, L3L4 11.5%, L4L5 23.9%, and L5S1 46.3%). A lower PI yielded a higher incidence of IDVP, particularly at L5S1 (p < 0.01). A total of 292 patients had IDVP with additional degenerative pathologies, which were more likely to occur at the level of isthmic spondylolisthesis, adjacent to a previous fracture or suprajacent to a lumbosacral transitional vertebra (p < 0.05).

CONCLUSIONS

This study identified the prevalence and severity of IDVP in an aging population. Sagittal patterns that influence the pattern of IVDP, such as pelvic incidence and degenerative pathologies, provide novel insights into the function of aging spines.

Severe Intervertebral Vacuum Phenomenon is Associated With Higher Preoperative Low Back Pain, ODI, and Indication for Fusion in Patients With Degenerative Lumbar Spondylolisthesis

STUDY DESIGN

Retrospective study of prospective collected data.

OBJECTIVE

To analyze the association between intervertebral vacuum phenomenon (IVP) and clinical parameters in patients with degenerative spondylolisthesis.

SUMMARY OF BACKGROUND DATA

IVP is a sign of advanced disc degeneration. The correlation between IVP severity and low back pain in patients with degenerative spondylolisthesis has not been previously analyzed.

METHODS

We retrospectively analyzed patients with degenerative spondylolisthesis who underwent surgery. Vacuum phenomenon was measured on computed tomography scan and classified into mild, moderate, and severe. A lumbar vacuum severity (LVS) scale was developed based on vacuum severity. The associations between IVP at L4/5 and the LVS scale, preoperative and postoperative low back pain, as well as the Oswestry Disability Index was assessed. The association of IVP at L4/5 and the LVS scale and surgical decision-making, defined as decompression alone or decompression and fusion, was assessed through univariable logistic regression analysis.

RESULTS

A total of 167 patients (52.7% female) were included in the study. The median age was 69 years (interquartile range 62-72). Overall, 100 (59.9%) patients underwent decompression and fusion and 67 (40.1%) underwent decompression alone. The univariable regression demonstrated a significantly increased odds ratio (OR) for back pain in patients with more severe IVP at L4/5 [OR=1.69 (95% CI 1.12-2.60), P =0.01]. The univariable regressions demonstrated a significantly increased OR for increased disability with more severe L4/L5 IVP [OR=1.90 (95% CI 1.04-3.76), P =0.04] and with an increased LVS scale [OR=1.17 (95% CI 1.02-1.35), P =0.02]. IVP severity of the L4/L5 were associated with higher indication for fusion surgery.

CONCLUSION

Our study showed that in patients with degenerative spondylolisthesis undergoing surgery, the severity of vacuum phenomenon at L4/L5 was associated with greater preoperative back pain and worse Oswestry Disability Index. Patients with severe IVP were more likely to undergo fusion.

Association between Modic changes and intervertebral vacuum phenomenon severity in patients undergoing percutaneous cement discoplasty

BACKGROUND

Modic changes and intervertebral vacuum phenomenon (IVP) are considered spinal degenerative changes. The correlation between Modic and IVP has not been analyzed in the literature.

PURPOSE

To analyze the correlation between IVP severity, Modic changes, and subchondral sclerosis across the lumbar spine in patients with lumbar degeneration.

MATERIAL AND METHODS

This is a retrospective study analyzing patients who underwent percutaneous cement discoplasty at a single institution between 2015 and 2020. Preoperative magnetic resonance imaging and computed tomography scans were analyzed to make the measurements. Modic type and grade as well as severity of IVP were preoperatively measured. The association between Modic type, grade, subchondral sclerosis, and the presence of IVP was analyzed.

RESULTS

In total, 110 patients (mean age = 77.03 ± 7.1 years) were finally included in the study. Per level correlation analysis showed a significant positive association between IVP and Modic type, IVP and Modic grade, and IVP and subchondral sclerosis. Moreover, subchondral sclerosis was significantly associated with Modic type and grade.

CONCLUSION

Our study showed a significant positive correlation among Modic changes, IVP, and subchondral sclerosis throughout the lumbar spine. Our findings support the theory that endplate degeneration parameters are associated with the presence and severity of IVP.

Complication Pattern After Percutaneous Cement Discoplasty: Identification of Factors Influencing Reoperation and Length of Hospital Stay

OBJECTIVE

Percutaneous cement discoplasty (PCD) was introduced to treat symptomatic vertical instability of the lumbar spine in a minimally invasive way. The aim of the present study was to analyze the complication pattern after PCD and to identify factors that predict the chance of cement leakage, reoperation, and length of hospital stay (LOS).

METHODS

patients were treated with PCD within the study period. Clinical features and complications were analyzed by applying descriptive statistics, whereas perioperative factors predictive of cement leakage, reoperation, and LOS were identified by regression models.

RESULTS

Cement leakage rate was 30.4% in the total cohort; however, only fifth of them were symptomatic. Cement leakage itself did not have a significant influence on clinical outcome. Other complications and nonsurgical adverse events were registered only in 2.0% of cases. Age, subcutaneous fat tissue thickness, low viscosity cement, lower level of surgeon's experience and the number of operated levels were identified as risk factors of cement leakage (P < 0.01; c-index = 0.836). Type of procedure, Charlson comorbidity score, reoperation, and nonsurgical adverse events significantly increased the LOS (P < 0.01). Cement leakage, early surgical practice, and increased subcutaneous fat tissue thickness were risk factors for reoperation (P < 0.01; c-index = 0.72).

CONCLUSIONS

PCD is a relatively safe and effective procedure for treating spinal instability caused by advanced-stage disc degeneration characterized by vacuum phenomenon. Cement leakage is not uncommon but is only a radiologic complication without clinical consequences in most cases. On the other hand, it can increase the LOS and is a significant risk factor for reoperation.

Evaluating Nonoperative Treatment for Low Back Pain in the Presence of Modic Changes: A Systematic Review

OBJECTIVE

The objective of this study was to summarize and assess the current literature evaluating nonoperative treatments for patients with Modic changes (MCs) and low back pain (LBP).

METHODS

A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The PubMed database was searched from its inception until May 1, 2022 for studies evaluating MC and clinical outcomes. Key findings, treatment details, and patient information were extracted from included studies. Study quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

Eighteen studies were included in this review, encompassing a total of 2452 patients, 1713 of whom displayed baseline MC. Seventy-eight percent of studies were high quality. Of included studies, 2 evaluated antibiotics, 5 evaluated steroid injections, 6 evaluated conservative therapies, and 5 evaluated other treatment modalities. Antibiotics and bisphosphonates improved treatment in patients with MC. Patients with MC without disc herniation benefited from conservative therapy, while those with Type I Modic changes and disc herniation experienced poorer improvement. Significant variability exists in reported outcomes following steroid injections.

CONCLUSIONS

Nonoperative therapy may provide patients with MC with significant benefits. Patients may benefit from therapies not traditionally utilized for LBP such as antibiotics or bisphosphonates, but conservative therapy is not recommended for patients with concomitant MC and disc herniation. The large variation in follow-up times and outcome measures contributes to significant heterogeneity in studies and inability to predict long-term patient outcomes. More long-term studies are needed to assess nonoperative treatments for LBP in patients with MC.

Development of a rat model with lumbar vertebral endplate lesion

PURPOSE

Vertebral endplate lesion (EPL) caused by severe disc degeneration is associated with low back pain. However, there is no suitable animal model to elucidate the pathophysiology of EPL. This study aimed to develop a rat model of EPL and evaluate rat behavior and imaging and histological findings.

METHODS

The L4-5 intervertebral discs of Sprague-Dawley rats were transperitoneally removed, except for the outer annulus fibrosus and cartilage endplate, in the EPL group. The L4-5 discs were not removed and simply exposed in the sham group. Changes around the vertebral endplate on magnetic resonance imaging (MRI) and computed tomography (CT) were evaluated. Additionally, pain-related behavioral and histological assessments were performed.

RESULTS

In the EPL group, a low-signal area around the vertebral endplate was observed on T1-weighted and T2-weighted fat-saturated MRI at 8 weeks or later after surgery. In the same group, CT showed osteosclerosis around the vertebral endplate at 12 weeks after surgery. The sham group did not show abnormal imaging features on the MRI and CT. Behavioral evaluation showed that the EPL group had a significantly longer grooming time than the sham group. Conversely, the 12-week postoperative locomotion time and the 1- and 12-week postoperative standing times were significantly shorter in the EPL group than in the sham group. Histological evaluation showed a high degree of vertebral endplate degeneration and an increased number of osteoclasts and proportion of nerve fibers expressing calcitonin gene-related peptide in the EPL group compared to those in the sham group.

CONCLUSION

Our rat EPL model showed pain-related behavioral patterns and an increased expression of pain-related neuropeptide. This model could contribute to the study of the pathophysiology of EPL and will help in the treatment of low back pain in the future.