The intervertebral disc is one of the major contributors to low back pain. Most low back pain is usually self-limiting, but it is sometimes prolonged which is major problem in clinical situations. Possible mechanisms of chronic discogenic low back pain are a prolonged low back pain state and repeated injured state. "Deep Nerve Ingrowth" into an injured intervertebral disc, pain-related molecules including inflammatory cytokines and nerve growth factors and continuous mechanical stress on injured intervertebral discs might be associated with the mechanism of chronic discogenic low back pain.

Low back pain and spinal deformity are issues to be overcome for Japan, aiming to extend healthy life expectancy. Trunk muscles play important roles in supporting the spinal column. However, few reports have investigated the relationship of the trunk muscle mass with lumbar spine disorder, and the clinical significance of the trunk muscle mass remains unclear. In this review, we introduce our previous report and summarize previous papers on trunk muscles. Our multicenter cross-sectional study included 1,738 patients (mean age: 70.2±11.0 years; 781 men and 957 women) who visited the spinal outpatient clinic. The trunk muscle mass showed a negative correlation with age (p < 0.001), and the decrease accelerated at approximately 70 years of age. The trunk muscle mass was significantly correlated with the the Oswestry Disability Index (ODI), visual analog scale (VAS) for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) (p < 0.001). Patient deterioration was associated with a decrease in the trunk muscle mass, and the deterioration accelerated from approximately 23 kg. The trunk muscle mass may play an important role to elucidate and treat lumbar spinal dysfunction and spinal deformity. It is necessary to conduct longitudinal studies to prove a causal relationship and establish an effective intervention method to maintain trunk muscles in the future.

Introduction: Pfirmann and Schneiderman classifications are mainly used to evaluate lumbar disc degenerations, however, there is no established classification method of disc degeneration for the cervical spine. The purpose of this study was to assess whether lumbar disc degeneration classifications can be used to evaluate cervical disc degeneration.

Methods: The subjects were 547 persons who underwent cervical spine MRI. Two lumbar disc degeneration classifications (Pfirmann and Schneiderman classifications) and five cervical disc degeneration classifications (Matsumoto's, Miyazaki's, Nakashima's, Jacobs', and Suzuki's classifications) were used to evaluate C2/3 to C7/T1 disc degeneration based on T2 weighted images with a mid-sagittal view. The relationship between the grade of each classification and age was examined using Spearman's correlation coefficient. The distribution of grades by intervertebral disc level was also assessed.

Results: In all classifications, age and grade were moderately correlated (0.412-0.547). The most severe intervertebral disc degeneration level was determined to be C5/6 based on all classifications.

Conclusions: In this study, there were no differences between the lumbar and cervical disc degeneration classifications. We concluded that cervical disc degeneration could be evaluated by lumbar disc degeneration classification.

Previous studies have reported increasing fat infiltration of paraspinal muscle especially intramyocellular lipids (IMCL) in multifidus muscle (Mm). The aim of this study was to longitudinally investigate the correlation between change of low back pain (LBP) and that of IMCL in Mm. The improvement ratio of LBP showed the correlation with change ratio of IMCL (r = 0.818, p < 0.001). Therefore, there were trend decreasing IMCL with improving LBP. It was suggested IMCL in Mm correlated with chronic LBP.

A deficiency in lumbar muscle blood circulation is considered to be a major risk factor for nonspecific low back pain. The aim of this study was to investigate changes in relative circulation over time in the lumbar multifidus in different positions on sitting.

Twelve healthy subjects (7 males, 5 females, average age: 20.9 years) without low back pain for the past twelve months were recruited. They received a full explanation and all agreed to participate in this study. Near-infrared spectroscopy (NIRS) was used to non-invasively measure total hemoglobin (Total-Hb) and oxygenated hemoglobin (Oxy-Hb) in the lumbar multifidus at the L5-S1 segment. All measurements were obtained in a neutral position, 60-degree trunk-flexed position, and 20-degree trunk-extended position on sitting. Subjects were asked to move into either a flexed or an extended position from the starting (neutral) position in 3 seconds, timed by a metronome, and to maintain these positions for 30 seconds. The angles of flexed and extended positions were measured with a goniometer, and self-made devices were used to properly maintain these positions. All participants received education and practice time in order to be able to adapt proper body movements and positions prior to assessment. The measurements of Total-Hb and Oxy-Hb were compared at -3 (neutral position), 0, 10, 20, and 30 seconds in each flexed and extended position on sitting.

In flexion, Total-Hb and Oxy-Hb of the lumbar multifidus were significantly decreased from a neutral (-3 seconds) to flexed (0 second) position (Total-Hb: p=0.002, Oxy-Hb: p=0.004); however, there were no significant differences in the flexed position. In extension, Total-Hb and Oxy-Hb of the lumbar multifidus were significantly increased from 0 to 10 seconds (Total-Hb: p<0.001, Oxy-Hb: p<0.001); however, there were no significant differences from the neutral (-3 seconds) to extended (0 second) position, or from 10 to 30 seconds.

The results of this study indicate that the intramuscular circulation of the lumbar multifidus decreases immediately once the trunk starts moving into a flexed position on sitting. On the other hand, the intramuscular circulation of the lumbar multifidus increases for up to 10 seconds once the trunk starts moving into an extended position. Therefore, it might be more beneficial for a person to avoid a flexed position and move into an extended position for therapeutic exercise in order to increase blood circulation of the lumbar multifidus on sitting.

Introduction: We investigated the clinical departments that patients with multiple myeloma first visited, their symptoms, and whether there was any delay in diagnosis.

Methods: A retrospective study was performed on 59 patients with multiple myeloma.

Results: Forty-five percent of patients first visited orthopedics. Diagnosis delay in orthopedics was 34.0%, and diagnosis delay in the orthopedic clinic was 63.6%. The symptoms at the first visit were 55.1% for orthopedic symptoms and 28.2% for internal medical symptoms. The most common symptom was low back pain, at 35.9%.

Conclusions: In order to diagnose multiple myeloma without delay, it is desirable to actively perform blood tests for patients with some red flag signs.

Objectives: Lumbar spinous process-splitting laminectomy (LSPSL) is one of the less invasive operative methods of decompression surgery for lumbar spinal stenosis (LSS). The aim of this research was to determine if multi-level decompression surgery was inferior to single-level decompression surgery when LSPSL was applied to LSS.

Materials and Methods: LSPSLs were performed for 39 patients with the cauda equina-type of LSS, and the patients were divided into three groups based on the number of decompressions (single level: 15 patients in group S, double level: 14 patients in group D, triple level: 10 patients in group T). Inclusion criteria consisted of: a lower grade of spondylolisthesis (less than Meyerding grade I), ranges of motion at decompression levels less than 20 degrees, Cobb angles less than 10 degrees, and durations of follow-up more than one year. The mean age of the patients was 69.7 years at the time of surgery, and the follow-up period averaged 21.5 months. Clinical outcomes were: JOA score, low back pain score of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), and visual analog scale (VAS) of low back pain. Dynamic lateral X-ray images were used to evaluate the translation of the vertebral bodies and range of motion at decompressed levels.

Results: There were no significant differences among the three groups at the pre-operative baseline. Average JOA scores were improved from 15.9 to 25.2 in group S, 16.2 to 23.2 in group D, and 15.7 to 24.6 in group T and VAS scores for low back pain were 5.2 to 2.1, 6.0 to 3.6, and 4.9 to 1.8 respectively. The gains in scores of JOABPEQ were 33.3 in group S, 34.6 in group D, and 28.7 in group T. All clinical outcomes revealed significant improvements at the last follow-up, and there was no evidence of worsening spondylolisthesis in any of the groups.

Conclusions: Based on short-term observation, multi-level decompression surgery was not inferior to single-level decompression surgery when LSPSL was applied to LSS patients.

Introduction: It has been reported that diagnosis of thoracic ossification of the ligament flavum (OLF) is delayed.

Methods: We retrospectively investigated neurosymptoms and the causes of delayed diagnosis of OLF.

Results: The diagnosis rate of OLF at the first visit was 39%. The final diagnosis was mostly delayed. The average delay period until diagnosis was 10.4 months. The compressed spinal cord group included many patients with deep tendon hyperreflexia and lumbar canal stenosis on MRI. In the conus group and epiconus group, patients had symptoms such as lumbar canal stenosis. These may be the cause of a delay in diagnosis.

Conclusions: It is important to pay careful attention to avoid overlooking the possible presence of thoracolumbar junction disease on lumbar spine MRI.

Introduction: Although the usefulness of exercise therapy for chronic low back pain is being recognized, the effects for patients with adult spinal deformity and chronic low back pain are only sporadically reported. In this study, the effect of exercise therapy on a patient with adult spinal deformity and chronic low back pain was verified, and its usefulness to relieve low back pain was examined.

Methods: Forty-three adults who had been diagnosed with spinal deformity were recruited for this study, and they received outpatient physical therapy intervention for three months. The patients were evaluated using the visual analogue scale (VAS for back pain), 6-minute walking ability test (6MWT), and Japanese Orthopaedic Association back pain evaluation questionnaire (JOABPEQ), before and after the intervention.

Results: Significant differences were observed in VAS, 6MWT, and JOABPEQ (low back pain, lumbar function, walking ability, and social life function domain) between pre- and post-intervention. Twenty-two patients (51%) showed an improvement of VAS over 20 mm, and the improvement was greater with a more favorable VAS before intervention.

Conclusions: The usefulness of exercise therapy for the patient with adult spinal deformity and chronic back pain was shown even in the first 3month. The presence of severe back pain before intervention indicated that its reduction could be expected.

In 2018, condoliase was approved as a less-invasive intermediate treatment for lumbar disc herniation (LDH), positioned between conservative treatment and surgery. Chemonucleolysis involves the injection of an enzyme into the intervertebral disc to dissolve the nucleus pulposus, thereby reducing intradiscal pressure on the nerve root and improving LDH symptoms. Condoliase is a foreign protein, and so the risk of anaphylaxis cannot be excluded. Patients should avoid unnecessary treatment. Therefore, it is important to predict the efficacy of condoliase before intermediate treatment. The aim of the present study was to determine an imaging factor that can be used to predict favorable clinical results.

Materials and Methods: We retrospectively studied 10 patients who received an intradiscal injection of condoliase and were followed for a 12-week period after administration between August 2018 and December 2018. Clinical evaluation involved the use of Oswestry Disability Index (ODI), with the omission of section 8. Disc degeneration was graded by Pfirrmann classification. We measured the disc height, dural sac area, and dissolved herniated mass on MRI. The effective group on imaging was defined as patients with a dissolved herniated mass area of more than 20 mm².

Results: The mean ODIs at the baseline and week 12 were 34.2 and 18.4, respectively. The mean area of the dissolved herniated mass was 7.8 mm², and there were 4 patients in the effective group on imaging. The median of the effective group on imaging was significantly lower than that of the non-effective group (P<0.05). The area of the dissolved herniated mass was significantly correlated with the disc degeneration grade (r=-0.65, P<0.05).

Conclusion: Condoliase was more effective against mild to early disc degeneration because it may reduce the size of the intervertebral disc by degrading glycosaminoglycans of proteoglycans in the nucleus pulposus, thereby reducing the water content and intradiscal pressure.

Purpose: There is no consensus of regarding the indication of surgical treatment of the less invasive decompression procedure for lumbar spinal stenosis (LSS). Although facet joint opening (FO) on preoperative computed tomography (CT) images has been reported as a parameter indicating segmental instability, there is no report on how FO affects on postoperative outcomes. The purpose of this study was to investigate risk factors for revision surgery after less invasive decompression surgery for LSS including FO by a minimum-5-year postoperative survey.

Materials and Methods: A total of 244 patients who underwent microscopic or microendoscopic decompression surgery for LSS and followed for ≥5 years were included in this study. We investigated revision lumbar surgeries at the same levels or other lumbar levels based on medical records. Revision surgeries due to postoperative hematoma or infection were excluded. FO was defined as a ≥2 mm opening on preoperative axial CT images at each lumbar intervertebral level. We evaluated the FO at index decompression levels and sum of FO-positive levels from L1-2 to L5-S. Risk factors for further surgeries were investigated among demographics, preoperative symptoms, and radiological parameters other than FO using univariate and cox proportional hazard regression analysis.

Results: There was 26 reoperations (10.7%) at a mean of 3.9 years after primary surgeries. FO at index decompression levels was significantly more frequent in patients with than without revision surgeries (69 and 39%, respectively, p=0.003). The sum of FO-positive levels among lumbar segments was significantly higher in patients with than without revision surgeries (2.0 and 1.2 levels, respectively, p=0.001). The cox proportional hazard regression analysis indicated that the sum of FO-positive levels among lumbar segments was one of the risk factors for revision surgery (p=0.003, adjusted hazard ratio: 1.47).

Conclusions: The FO of index decompression levels and sum of FO were associated with the need for further lumbar surgeries after less invasive surgery. FO might indicate not only segmental instability but also predictive parameter for progression of degenerative change.