Full-endoscopic Spine Surgery for Discogenic Low Back Pain with High-intensity Zones and Modic Type 1 Change in a Professional Baseball Player

Non-specific low back pain in athletes can be caused by discogenic back pain, Modic type 1 change, and facet joint arthritis. In this report, we describe a full-endoscopic surgical strategy that we have used to treat a patient with both discogenic pain and Modic type 1 change. The patient was a 32-year-old professional baseball player who played an infield position and had a 2-year history of low back pain. Three years earlier, he had undergone micro-endoscopic discectomy for left herniated nucleus pulposus at L5/S1. His leg symptoms resolved postoperatively, and he returned to playing baseball the following season. However, his low back pain gradually increased. Two years after the initial surgery, he was experiencing low back pain in daily life and found it very difficult to play baseball. Short T1 inversion recovery (STIR) magnetic resonance imaging (MRI) revealed Modic type 1 change and high-signal intensity zones in degenerated discs at L4/5 and L5/S1. Injection of xylocaine 1% reduced the pain temporarily, confirming that the pain generator was at L4/5 and L5/S1. The pathological diagnosis was discogenic pain with Modic type 1 change. We performed full-endoscopic disc cleaning (FEDC) surgery for the Modic type 1 change and thermal annuloplasty (TA) for the discogenic pain at these levels. The patient's low back pain decreased steadily thereafter. Six months after surgery, he returned to baseball, playing for a full season without pain. We have successfully treated a professional baseball player with discogenic pain and Modic type 1 change by full-endoscopic surgery.

Treatment of Low Back Pain by Treating the Annular High Intensity Zone (HIZ) Lesions Using Percutaneous Transforaminal Endoscopic Disc Surgery

Background

The study design was a retrospective case series. The objective was to find the clinical success rate of percutaneous transforaminal endoscopic disc surgery in patients suffering from discogenic chronic low back pain who were showing high intensity zone (HIZ) with degenerated disc as the only abnormality in the magnetic resonance imaging (MRI). The HIZ in the posterior annulus in degenerated disc is recognized as a pain generator. There are only a few studies available in the literature addressing the effect of identification and treatment of HIZ in the chronic low back pain patient.

Methods

We retrospectively evaluated the case records of all the patients who were treated by percutaneous endoscopic disc surgery for relief of symptoms as determined by visual analog scale (VAS) score, Oswestry Disability Index (ODI), Mac Nab criteria, and the consumption of analgesics, who had the predominant symptom of chronic low back pain, and whose lumbar spine MRI showed degenerated disc with HIZ and no other cause of back pain, like facet joint arthritis or sacroiliac joint arthritis.

Results

A total of 23 patients were identified to include in the study. Mean preoperative duration of low back pain was 13.1 months. Mean follow up after the procedure was 29 months. At final follow up, 69.6% of the patients were not taking any pain medicines, 17.36% were on frequent analgesic medicines, 13.04% were on occasional analgesics. There was statistically significant reduction in VAS at 6 weeks postop and final follow up after surgery and the ODI at final follow up; 82.6% of patients had an excellent/good outcome as per Mac Nab criteria. There were no complications or reoperations in any of the patients.

Conclusions

Visualization and ablation of the chronic annular pathology in HIZ may give an effective and minimally invasive treatment for one of the back pain causes.

[Changes in shape and signal intensity of high intensity zone in lumbar intervertebral discs on magnetic resonance images: a longitudinal study]

OBJECTIVE

To investigate changes over time in the shape and signal intensity of high intensity zone (HIZ) in the lumbar intervertebral discs on magnetic resonance images in patients with low back pain.

METHODS

The imaging data were collected from 27 patients with low back pain, who underwent lumbar magnetic resonance (MR) imaging examinations that identified HIZ lesions and received follow-up MR examinations at least 1.5 years later over the period from January 2009 to January 2017. The initial and follow-up MR T2WI images of the patients were read by two experienced radiologists to categorize the changes in the shape of the HIZ lesions into enlarged, unchanged, shrunk, and disappeared. The volume and signal/cerebrospinal fluid signal intensity (T2/CSF) ratio of the HIZ were measured on sagittal MR images using ImageJ software.

RESULTS

Of the 43 HIZ lesions found in the initial examinations, 22 (51.2%) remained unchanged in the follow-up examinations, 10 (21.3%) were enlarged, 9 (20.9%) shrank, and 2 (23.3%) disappeared. The follow-up examinations revealed 4 new HIZ lesions in the intervertebral discs. The volumes of these lesions did not vary significantly in the follow-up examinations (P=0.653), but the T2/CSF ratio was significantly higher in the follow-up than in the initial examinations (P=0.043).

CONCLUSIONS

After observation for an average of 3 years and 3 months, most of the HIZ lesions in the lumbar intervertebral discs of the patients with low back pain remained stable in shape, but their signal intensity on MR images increased.

Simulation of water content distributions in degenerated human intervertebral discs

The objective of this study was to investigate the spatial and temporal variations of water content in intervertebral discs during degeneration and repair processes. We hypothesized that the patterns of water content distribution in the discs are related to the intensity patterns observed in T2-weighted MRI images. Water content distributions in the mildly (e.g., 80% viable cells in the disc, 2.3% decrease in disc height) and moderately (e.g., 40% viable cells in the disc, 9.3% decrease in disc height) degenerated discs were predicted using a finite element model. The variation of water content in the degenerated discs treated with three biological therapies (i.e., increasing the cell density in the nucleus pulposus [Case I], increasing glycosaminoglycan synthesis rate in the nucleus pulposus [Case II], and decreasing glycosaminoglycan degradation rate in the nucleus pulposus [Case III]) were also predicted. It was found that two patterns of water content distributions, a horizontal region with lower water content at the mid-axial plane of nucleus pulposus and a spot with higher water content at the posterior region, were shown during the degeneration progress for the disc simulated in this study. These two patterns disappeared after treatment in Case I, but in Case II and Case III. The implication of these patterns for the horizontal gray band and high intensity zone in T2-weighted MRI images was discussed. This study provided new guidance to develop a novel method for diagnosing disc degeneration and assessing outcomes of biological therapies with MRI techniques. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:147-153, 2017.

Low back pain associated with lumbar disc herniation: role of moderately degenerative disc and annulus fibrous tears

Lumbar disc herniation is one of the most common spinal degenerative disorders which may lead to low back pain (LBP) and radicular leg pain. However, it remains difficult to diagnose a degenerative herniated disc as the LBP generator in clinical practice. The purpose of this study is to explore the characteristic changes of a herniated disc causing LBP on MRI and to clarify the underlying role of inflammatory mediators and annulus fibrous (AF) tears in LBP generation associated with disc herniation. We prospectively collected intervertebral disc specimens and MRI from 57 single-segment disc herniation patients with radiculopathy. All subjects were grouped according to LBP occurrence or disc degeneration severity for the comparison of inflammatory mediators' expression and AF tears occurrence (High Intensity Zone, HIZ, on MRI). LBP incidence under circumstances of different degeneration severity with or without HIZ was further analyzed. Both LBP incidence and Inflammatory mediators expression in moderately degenerated group was higher than mildly and severely degenerative groups. HIZ incidence was higher in moderately and severely degenerated groups. LBP incidence in the patients with both moderately degenerated discs and HIZ was 86.7%, much higher than the rest of the patient population. In conclusion, the high expression of inflammatory mediators with AF tears causes LBP associated with disc herniation. Moderately degenerative disc with HIZ is MRI morphological change of herniated disc causing LBP, which can be applied to diagnose LBP.

Clinical presentation of low back pain and association with risk factors according to findings on magnetic resonance imaging

We hypothesised that the relative importance of physical and psychological risk factors for mechanical low back pain (LBP) might differ importantly according to whether there is underlying spinal pathology, psychological risk factors being more common in patients without demonstrable pathology. If so, epidemiological studies of LBP could benefit from tighter case definitions. To test the hypothesis, we used data from an earlier case-control study on patients with mechanical LBP who had undergone magnetic resonance imaging (MRI) of the lumbosacral spine. MRI scans were classified for the presence of high-intensity zone (HIZ), disc degeneration, disc herniation, and nerve root displacement/compression. Information about symptoms and risk factors was elicited by postal questionnaire. Logistic regression was used to assess associations of MRI abnormalities with symptoms and risk factors, which were characterised by odds ratios (ORs) and 95% confidence intervals (CIs). Among 354 patients (52% response), 306 (86.4%) had at least 1, and 63 (17.8%) had all 4 of the MRI abnormalities. Radiation of pain below the knee (280 patients) and weakness or numbness below the knee (257 patients) were both associated with nerve root deviation/compression (OR 2.5, 95% CI 1.4 to 4.5; and OR 1.8, 95% CI 1.1 to 3.1, respectively). However, we found no evidence for the hypothesised differences in risk factors between patients with and without demonstrable spinal pathology. This suggests that when researching the causes and primary prevention of mechanical LBP, there may be little value in distinguishing between cases according to the presence or absence of the more common forms of potentially underlying spinal pathology.