古矢 丈雄

OBJECTIVE: Laminoplasty is an effective procedure for treating cervical spondylotic myelopathy. We conduct myovascular preserving open-door laminoplasty (MPLP) in combination with a laminoplasty plate to improve the stability of the enlarged lamina. We compare the details of the MPLP technique with conventional open-door laminoplasty. METHODS: We compared 25 cases of MPLP (mean age = 70.5, mean follow-up period = 19 months) with 15 controls who received conventional open-door laminoplasty using hydroxyapatite spacers (mean age = 74, mean follow-up period = 53 months). Regarding surgical outcomes, blood loss, operative time, Japanese Orthopaedic Association score, and postoperative visual analog score for neck pain were measured. Regarding image analysis, preoperative and postoperative range of motion (ROM), C2-7 angle, implant back out, hinge bone fusion time, presence or absence of hinge bone union failure, and posterior neck fat infiltration rate were evaluated. RESULTS: Operative time was significantly shorter for MPLP, and postoperative neck pain was significantly decreased. In image evaluation, %ROM was significantly increased in MPLP, but no difference in C2-7 angle existed between the 2 groups. Implant back out was not recognized in either group. In MPLP, the hinge union period was significantly shortened, and the postoperative fat infiltration rate was significantly decreased. CONCLUSIONS: We were able to reduce neck pain after surgery by an approach entailing longitudinal splitting of the spinous processes. We were able to ensure shorter operation times due to cervical plates and better hinge bone fusion times due to initial stability. LEVEL OF EVIDENCE: 4.

We sought to assess the utility of simultaneous apparent T2 mapping and neurography with the nerve-sheath signal increased by inked rest-tissue rapid acquisition of relaxation-enhancement imaging (SHINKEI-Quant) for the quantitative evaluation of compressed nerves in patients with lumbar radiculopathy.Thirty-two patients with lumbar radiculopathy and 5 healthy subjects underwent simultaneous apparent T2 mapping and neurography with SHINKEI-Quant. Regions of interest (ROIs) were placed in the lumbar dorsal root ganglia (DRG) and the spinal nerves distal to the lumbar nerves bilaterally at L4-S1. The T2 relaxation times were measured on the affected and unaffected sides. The T2 ratio was calculated as the affected side/ unaffected side. Pearson correlation coefficients were calculated to determine the correlation between the T2 relaxation times or T2 ratio and clinical symptoms. An ROC curve was used to examine the diagnostic accuracy and threshold of the T2 relaxation times and T2 ratio.We observed no significant differences in the T2 relaxation times between the nerve roots on the left and right at each spinal level in healthy subjects. In patients, lumbar neurography revealed swelling of the involved nerve, and prolonged T2 relaxation times compared with that of the contralateral nerve. The T2 ratio correlated with leg pain. The ROC analysis revealed that the T2 relaxation time threshold was 127 ms and the T2 ratio threshold was 1.07.To our knowledge, this is the first study to show the utility of SHINKEI-Quant for the quantitative evaluation of lumbar radiculopathy. (C) 2020 Elsevier Ltd. All rights reserved.

PURPOSE: Diffusion tensor imaging (DTI) is useful to evaluate lumbar nerves visually and quantitatively. Multi-band sensitivity encoding (MB-SENSE) is a technique to reduce the scan time. This study aimed to investigate if super-multi-gradient DTI with multi-band sensitivity encoding (MB-SENSE) is better in evaluating lumbar nerves than the conventional method. METHODS: The participants were 12 healthy volunteers (mean age 33.6 years). In all subjects, DTI was performed using echo planar imaging with different motion probing gradient (MPG) directions (15 without MB, and 15, 32, 64, and 128 with MB) and the lumbar nerve roots were visualized with tractography. In the five groups, we evaluated the resultant DTI both visually and quantitatively. For visual measures, we counted the number of fluffs and disruptions of the nerve fibers. For quantitative measures, the fractional anisotropy (FA) and standard deviation of the fractional anisotropy (FA-SD) values at two regions (proximal and distal) of the lumbar nerve roots were quantified and compared. RESULTS: Among the five groups, the number of fluffs decreased as the number of MPG directions increased. However, the number of disruptions showed no significant differences. The FA-SD values decreased as the number of MPG directions increased, indicating that the signal variation was reduced with multi-gradient directional DTI. CONCLUSION: High-resolution multi-directional DTI with MB-SENSE may be useful to visualize nerve entrapments and may allow for more accurate DTI parameter quantification with opportunities for clinical diagnostic applications.

Objective: Atopic dermatitis (AD) is one of the known risk factors for Staphylococcus aureus infection. The authors report the case of a patient with cervical spondylosis and AD who developed delayed surgical site infection after posterior cervical instrumented surgery. Patient: A 39-year-old male presented to our hospital with paralysis of the left upper extremity without any cause or prior injury. He had a history of severe AD. We performed C3-C7 posterior decompression and instrumented fusion based on the diagnosis of cervical spondylotic amyotrophy. One year after surgery, his deltoid and bicep muscle strength were fully recovered. Nevertheless, his neck pain worsened 2 years after surgery following worsening of AD. One month after that, he developed severe myelopathy and was admitted to our hospital. Radiographic findings showed that all the screws had loosened and the retropharyngeal space had expanded. Magnetic resonance imaging and computed tomography showed severe abscess formation and destruction of the C7/T1 vertebrae. Result: We diagnosed him with delayed surgical site infection. Methicillin-resistant Staphylococcus aureus was identified on abscess culture. The patient responded adequately to treatment with antibiotic therapy and two debridements and the infection subsided. Conclusion: We should consider the possibility of delayed surgical site infection when conducting instrumented spinal surgery in patients with severe AD.

STUDY DESIGN: Observational study. PURPOSE: To evaluate healthy volunteers and patients with spinal canal lesions using apparent diffusion coefficient (ADC) maps with diffusion-weighted imaging. OVERVIEW OF LITERATURE: Decompression surgery for lumbar spinal stenosis (LSS) is selected on the basis of subjective assessment and cross-sectional magnetic resonance imaging (MRI). However, there is no objective standard for this procedure. METHODS: We performed 3T MRI in 10 healthy volunteers and 13 patients with LSS. The ADC values in the spinal canal were evaluated at 46 vertebrae (L4/5 and L5/S1 for each participant), and the reduced and conventional fields of view were compared. RESULTS: The ADC values were 2.72±0.12 at L4/5 in healthy volunteers, 2.76±0.19 at L5/S1 in healthy volunteers, 1.77±0.58 at L4/5 in patients with LSS, and 2.35±0.29 at L5/S1 in patients with LSS. The ADC value at L4/5 in patients with LSS was significantly lower than that at L5/S1 in patients with LSS and that at L4/5 and L5/S1 in healthy volunteers (p <0.05). With an ADC cutoff value of 2.46 to identify LSS, this approach provided an area under the curve of 0.81, sensitivity of 0.92, and specificity of 0.76 (p <0.05). CONCLUSIONS: Preoperative examination using ADC maps permits visualization and quantification of spinal canal lesions, thus proving the utility of ADC maps in the selection of decompression surgery for LSS.

STUDY DESIGN: Prospective multi-center study. OBJECTIVE: The aim of this study was to evaluate the effectiveness of surgical treatment in reducing falls and fall-related neurological deterioration in a prospective cohort of patients undergoing surgery for degenerative cervical myelopathy (DCM). SUMMARY OF BACKGROUND DATA: Current evidence is limited for the effectiveness of surgical interventions for DCM in reducing the risk of fall-related neurological deterioration. METHODS: Patients with DCM scheduled for surgical treatment were enrolled prospectively at eight participating institutes. At the time of enrollment, participants were given diaries to record details of their falls, to be returned at the 1-year postoperative follow-up. In the fall diary, patients were asked whether they had experienced any deterioration in neurological symptoms at each fall episode. Deterioration of neurological symptoms was categorized as follows: only deterioration of sensory function in the limbs; or deterioration of motor deficits. The incidence rate of falls was calculated separately for the preoperative and postoperative periods, as the total number of falls divided by the time over which falls were monitored (100 person-years). Functional outcome was assessed with the Japanese Orthopaedic Association (JOA) score and Neck Disability Index. RESULTS: Of the initial 168 participants, 159 completed the 1-year follow-up, and 132 fall diaries were retrieved and analyzed. Of these 132 patients, 65 (49%) reported at least one fall during the survey period. The incidence rate of falls decreased significantly from 497.4 to 90.3 falls per 100 person-years after surgery. The incidence of motor deterioration per fall decreased significantly from 34% to 8% after surgery. Patients who experienced preoperative fall-related motor deterioration had a significantly lower JOA score compared with patients without fall-related motor deterioration at 1-year follow-up. CONCLUSION: Surgical intervention for DCM is effective not only in reducing the frequency of falls, but also in reducing the risk of fall-related deterioration of motor deficits. LEVEL OF EVIDENCE: 2.

The purpose of this study was to try oblique lateral interbody fusion (OLIF) using percutaneous pedicle screws (PPS) with mobility. Twelve patients who underwent single-level OLIF were observed for at least one year. These included 6 patients with conventional PPS (rigid group), and 6 with movable PPS (semi-rigid group). Mobile PPS used cosmicMIA, which is a load sharing system. The anterior and posterior disc height, screw loosening and bone healing period, and implant failure were evaluated at final observation by CT. Moreover, the stress on the vertebral body-cage, on the vertebral body-screw/rod and on the bone around the screw was estimated using a three-dimensional finite element assessment in both groups. There was no significant difference in surgical time, amount of bleeding, JOA score, or low back pain VAS between groups. There were no differences between groups in anterior and posterior disc height, screw loosening, and implant failure at final observation. The bone healing period was significantly shorter in the semi-rigid screw group (18.3 months vs 4.8 months, p = 0.01). The finite element analysis showed that the lower stress on the rod/screw would contribute to fewer implant fractures and that lower stress on the bone around the screw would reduce screw loosening, and that higher compressive force on the cage would promotes bone healing. OLIF combined with a movable screw accelerated bone healing by nearly 75%. We conclude that mobile PPS in combination with OLIF promotes bone healing and can be a better vertebral fusion technique.

かつて腰痛疾患の85%を占めると謳われた非特異的腰痛の病態は,近年の医学研究の推進とともに解明されつつある。慢性疼痛の機序には腰痛疾患患者の約30%が罹患する神経障害性疼痛の概念が重要であり,特に臀部痛の存在は神経障害性疼痛の可能性を示唆する。椎間板性腰痛は変性椎間板で産生される炎症性サイトカインおよび異常感覚神経の伸長など複数の分子生物学的機序を介して慢性腰痛の一端を担い,これに基づくブロック療法等が報告されている。(著者抄録)

かつて腰痛疾患の85%を占めると謳われた非特異的腰痛の病態は,近年の医学研究の推進とともに解明されつつある。慢性疼痛の機序には腰痛疾患患者の約30%が罹患する神経障害性疼痛の概念が重要であり,特に臀部痛の存在は神経障害性疼痛の可能性を示唆する。椎間板性腰痛は変性椎間板で産生される炎症性サイトカインおよび異常感覚神経の伸長など複数の分子生物学的機序を介して慢性腰痛の一端を担い,これに基づくブロック療法等が報告されている。(著者抄録)

Atlantoaxial rotatory fixation (AARF) in an adult without any trauma is an extremely rare condition. Here we report a case of surgical treatment for existing atlantoaxial rotatory fixation in an adult with spastic torticollis. A 50-year-old man had become aware of torticollis without any cause of injury 6 weeks before he visited our hospital, where he presented with a one-week history of severe neck pain. Based on the local and imaging findings, we diagnosed him as having existing AARF of Fielding classification type I. The AARF was not reduced by 3 weeks of Glisson traction. Thus, we performed C1-C2 posterior fusion surgery 3 months after his initial visit. Although CT findings just after surgery showed that the C1-2 facet subluxation was reduced, the complaint of torticollis was not improved, with scoliosis at the middle to lower cervical level because of left sternocleidomastoid hypertonia. Administration of diazepam was initiated 2 weeks after surgery and botulinum toxin injections to the left sternocleidomastoid were added 2 months after surgery under the neurological diagnosis of spastic torticollis. As a result, the complaint of his torticollis was significantly improved 3 months after surgery. There were no relapses of the torticollis and complete fusion of the C1-C2 laminae was observed at the 2-year final follow-up. Surgical treatment for AARF in an adult should be considered if the diagnosis of AARF is delayed. In addition, appropriate treatment for spastic torticollis applied after surgery resulted in a favorable outcome of this case.

There is no imaging modality to quantitatively evaluate compressed cervical nerve roots in cervical radiculopathy. Here we sought to evaluate the usefulness of simultaneous apparent T2 mapping and neurography with nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation-enhancement imaging (SHINKEI-Quant) to evaluate compressed nerves quantitatively in patients with cervical radiculopathy due to cervical disc hernia before microendoscopic surgery. One patient with cervical radiculopathy due to cervical disc hernia before microendoscopic surgery and 5 healthy subjects underwent simultaneous apparent T2 mapping and neurography with SHINKEI-Quant. The patient was a 49-year-old man with severe right upper arm pain and numbness. Based on MRI images, we suspected right C7 radiculopathy due to C6-7 cervical disc hernia. The T2 relaxation times of the cervical dorsal root ganglia of the brachial plexus bilaterally at C5-C8 were measured. We observed no significant differences in T2 relaxation times between the nerve roots on the left and right at each spinal level with values in healthy subjects. In our patient, neurography revealed swelling of the right C7 nerve, and a prolonged T2 relaxation time compared with that of the contralateral, unaffected C7 nerve. We performed microendoscopic surgery and the symptoms improved. We were able to evaluate the injured nerve root quantitatively in a patient with cervical radiculopathy using the SHINKEI-Quant technique, being the first study to our knowledge to show the usefulness of this technique to evaluate cervical radiculopathy quantitatively before microendoscopic surgery.

Previous studies have reported the utility of diffusion tensor imaging (DTI) as an imaging biomarker for the severity of myelopathy and subsequent surgical outcome in patients with degenerative cervical myelopathy (DCM). We hypothesized that DTI may reflect neurological recovery following surgery. The purpose of this study was to evaluate the ability of DTI to assess the post-operative alteration of neural status in patients with DCM as well as to predict post-operative recovery. We enrolled 15 patients with DCM who underwent decompression surgery. The Japanese Orthopaedic Association (JOA) score was evaluated before and 1 year after surgery. The participants were examined using DTI on a 3.0 T magnetic resonance scanner before, and 1 year after surgery. Fractional anisotropy (FA) and mean diffusivity (MD) were assessed for both time points. The correlations between the pre- and post-operative FA and MD values and the pre- and post-operative JOA scores were analyzed. Although the JOA score improved significantly after surgery from 8.9 to 12.3, there was no significant change between the pre- and post-operative FA and MD values. The post-operative outcomes after 1 year moderately correlated with the pre-operative FA values (Spearman's ρ = 0.55, p = 0.03 and Spearman's ρ = 0.56, p = 0.03 for change and recovery rate of the JOA score, respectively). However, there was no correlation between the post-operative FA and post-operative JOA scores nor between MD and clinical outcomes. DTI cannot be utilized as a biomarker for post-operative alterations of neural status of the spinal cord; however, pre-operative DTI may be useful as a predictor of surgical outcomes.

Ossification of the posterior longitudinal ligament (OPLL) can occur throughout the entire spine and can sometimes lead to spinal disorder. Although patients with OPLL sometimes develop physical limitations because of pain, the characteristics of pain and effects on activities of daily living (ADL) have not been precisely evaluated in OPLL patients. Therefore, we conducted a multi-center prospective study to assess whether the symptoms of cervical OPLL are different from those of cervical spondylosis (CS). A total of 263 patients with a diagnosis of cervical OPLL and 50 patients with a diagnosis of CS were enrolled and provided self-reported outcomes, including responses to the Japanese Orthopaedic Association (JOA) Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), JOA Back Pain Evaluation Questionnaire (JOABPEQ), visual analog scale (VAS), and SF-36 scores. The severity of myelopathy was significantly correlated with each domain of the JOACMEQ and JOABPEQ. There was a negative correlation between the VAS score for each domain and the JOA score. There were significantly positive correlations between the JOA score and the Mental Health, Bodily Pain, Physical Functioning, Role Emotional, and Role Physical domains of the SF-36. One-to-one matching resulted in 50 pairs of patients with OPLL and CS. Although there was no significant between-group difference in scores in any of the domains of the JOACMEQ or JOABPEQ, the VAS scores for pain or numbness in the buttocks or limbs were significantly higher in the CS group; however, there was no marked difference in low back pain, chest tightness, or numbness below the chest between the two study groups. The scores for the Role Physical and Body Pain domains of the SF-36 were significantly higher in the OPLL group than in the CS group, and the mean scores for the other domains was similar between the two groups. The results of this study revealed that patients with OPLL were likely to have neck and low back pain and restriction in ADL. No specific type of pain was found in patients with OPLL when compared with those who had CS.