牧 聡

BACKGROUND: According to most of the commonly used classification systems for subaxial spine injuries, unilateral and minimally displaced facet fractures without any sign of a spinal cord injury would be directed to non-operative management. However, the failure rate of non-operative treatment varies from 20 to 80%, and no consensus exists with regard to predictors of failure after non-operative management. CASE PRESENTATION: Case 1 is a patient with a unilateral facet fracture. The patient had only numbness in the right C6 dermatome but failed non-operative treatment, which resulted in severe spinal cord injury. Case 2 is a patient who had a similar injury pattern as case 1 but presented with immediate instability and underwent fusion surgery. Both patients had a minimally displaced unilateral facet fracture accompanied by disc injury and blunt vertebral artery injury, which are possible signs indicating significant instability. CONCLUSIONS: This is the first report of an isolated unilateral facet fracture that resulted in catastrophic spinal cord injury. These two cases illustrate that an isolated minimally displaced unilateral facet fracture with disc injury and vertebral artery injury were associated with significant instability that can lead to spinal cord injury.

Advanced glycation end-products (AGEs) have been reported as a possible biomarker of ageing and metabolic diseases; however, its role in the clinical progression of these diseases remains unclear. We aimed to evaluate how AGEs are associated with clinical symptoms and comorbidities in lower back pain (LBP) patients. This prospective cohort study enrolled 636 LBP patients. They were subjected to quantified AGE (qAGE) analysis using skin autofluorescence, and their clinical symptoms and comorbidities, such as diabetes, renal failure with haemodialysis treatment, and osteoporosis, were measured. LBP, lower extremity pain, and numbness were evaluated using a visual analogue scale (VAS). The measured qAGE was significantly higher in subjects with any comorbidity. Age also showed a strong positive correlation with qAGE. qAGE and VAS for leg numbness were positively correlated. Furthermore, in LBP patients under 50-years-old, qAGE was positively correlated with VAS for LBP, lower extremity pain, and numbness. In conclusion, qAGE, as measured by skin autofluorescence measurement, was significantly higher in LBP patients with diabetes and dialysis, as well as in osteoporosis patients. Furthermore, qAGE showed potential as a biomarker for LBP, lower extremity pain, and numbness in patients under 50-years-old. If accumulated AGEs are identified at a young age, researchers should be vigilant for the development of osteoporosis and LBP-related clinical symptoms later in life.

Lumbar lateral interbody fusion (LLIF) has been gaining popularity among the spine surgeons dealing with degenerative spinal diseases while LLIF on L5-S1 is still challenging for its technical and anatomical difficulty. OLIF51 procedure achieves effective anterior interbody fusion based on less invasive anterior interbody fusion via bifurcation of great vessels using specially designed retractors. The technique also achieves seamless anterior interbody fusion when combined with OLIF25. A thorough understanding of the procedures and anatomical features is mandatory to avoid perioperative complications.

This study aimed to clarify whether ossification predisposition influences clinical symptoms including pain, restriction of activities of daily living, and quality of life in patients with cervical ossification of the posterior longitudinal ligament (OPLL). Cervical ossification predisposition potentially causes neurologic dysfunction, but the relationship between clinical symptoms and radiologic severity of OPLL has not yet been investigated. Data were prospectively collected from 16 institutions across Japan. We enrolled 239 patients with cervical OPLL. The primary outcomes were patient-reported outcomes, including visual analog scale (VAS) pain scores and other questionnaires. Whole-spine computed tomography images were obtained, and correlations were investigated between clinical symptoms and radiologic findings, including the distribution of OPLL, the sum of the levels where OPLL was present (OP-index), and the canal narrowing ratio (CNR) grade. The cervical OP-index was Grade 1 in 113 patients, Grade 2 in 90, and Grade 3 in 36. No significant correlations were found between radiologic outcomes and VAS pain scores. The cervical OP-index was associated with lower extremity function, social dysfunction, and locomotive function. The CNR grade was not correlated with clinical symptoms, but Grade 4 was associated with lower extremity dysfunction. Thickness and extension of ossified lesions may be associated with lower extremity dysfunction in cervical OPLL.

＜文献概要＞はじめに 骨粗鬆症患者で最も骨折が多発する部位は椎体であり,年間140万人に新たな脆弱性椎体骨折が発生していると報告されている.脆弱性椎体骨折を受傷すると,強い疼痛による著しいADL低下(活動制限とそれに伴う廃用)が必発である.さらに,Quality of Life Questionnaire of the European Foundation for Osteoporosis(QUALEFFO)を用いて調査した報告では,脆弱性椎体骨折があると身体機能のみならず,社会機能,全体的健康観までもが低下するとも報告されている.つまり,その影響はQOL低下にまで及ぶといえる.したがって,疼痛のみならずADLおよびQOLの観点からも脆弱性椎体骨折に対する適切な治療介入が重要なのはいうまでもない.そこで本稿では,脆弱性椎体骨折に対する痛み治療のストラテジーについて,(1) 一般的な腰痛治療の観点,(2)脆弱性椎体骨折特有の観点といった2つの面から概説する.

Background and purpose - Deep-learning approaches based on convolutional neural networks (CNNs) are gaining interest in the medical imaging field. We evaluated the diagnostic performance of a CNN to discriminate femoral neck fractures, trochanteric fractures, and non-fracture using antero-posterior (AP) and lateral hip radiographs. Patients and methods - 1,703 plain hip AP radiographs and 1,220 plain hip lateral radiographs were included in the total dataset. 150 images each of the AP and lateral views were separated out and the remainder of the dataset was used for training. The CNN made the diagnosis based on: (1) AP radiographs alone, (2) lateral radiographs alone, or (3) both AP and lateral radiographs combined. The diagnostic performance of the CNN was measured by the accuracy, recall, precision, and F1 score. We further compared the CNN's performance with that of orthopedic surgeons. Results - The average accuracy, recall, precision, and F1 score of the CNN based on both anteroposterior and lateral radiographs were 0.98, 0.98, 0.98, and 0.98, respectively. The accuracy of the CNN was comparable to, or statistically significantly better than, that of the orthopedic surgeons regardless of radiographic view used. In the CNN model, the accuracy of the diagnosis based on both views was significantly better than the lateral view alone and tended to be better than the AP view alone. Interpretation - The CNN exhibited comparable or superior performance to that of orthopedic surgeons to discriminate femoral neck fractures, trochanteric fractures, and non-fracture using both AP and lateral hip radiographs.

STUDY DESIGN: A retrospective case-control study. OBJECTIVE: The objective of this study was to assess mid-term surgical outcomes after posterior decompression with instrumented fusion (PDF) in patients with K-line (-) type cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: The poor surgical outcome for K-line (-) type cervical OPLL can result from posterior decompression alone. MATERIALS AND METHODS: We reviewed cases of K-line (-) type cervical OPLL in 24 patients who underwent PDF in our institute from 2002 to 2014. As a control, we used K-line (-) type cervical OPLL in 9 patients who underwent laminoplasty before 2002 (LMP group). The neurological status and radiographic findings were evaluated retrospectively. RESULTS: The preoperative Japanese Orthopedic Association score was 7.9±2.4 points in the PDF group and 7.4±2.3 points in the LMP group (P=0.584). The postoperative Japanese Orthopedic Association score was 11.7±2.6 points in the PDF group and 9.2±2.0 points in the LMP group at a 5-year follow-up (P=0.008). The recovery rate on average was 39.0% in the PDF group and 14.9% in the LMP group at a 5-year follow-up (P=0.037). The range of motion postoperatively at the maximal spinal cord compression level decreased significantly in the PDF group. The C2-C7 angle was 2.7 degrees of kyphosis in the PDF group, whereas 5.5 degrees of kyphosis was found in the LMP group at a 5-year follow-up (P=0.303). The center of gravity of the head-C7 sagittal vertical axis was 40 mm in the PDF group and 43 mm in the LMP group (P=0.936). CONCLUSIONS: The relatively good surgical outcome could be obtained by PDF for patients with K-line (-)-type cervical OPLL. The addition of posterior instrumented fusion eliminated the dynamic factor at the level of maximal spinal cord compression. LEVEL OF EVIDENCE: Level IV.

PURPOSE: To elucidate the independent preoperative factors that have a significant impact on poor surgical outcome after laminoplasty for K-line (+) ossification of the posterior longitudinal ligament (OPLL). Analyses in K-line (+) patient population can exclude the influence by mal-alignment and thick OPLL, both of which are well known two major factors that have significant impact on clinical outcome. METHODS: The present study included 72 patients (50 male and 22 female) who underwent laminoplasty for K-line (+) cervical OPLL and were followed-up for at least 1 year. Recovery of Japanese Orthopedic Association score (JOA score) for cervical myelopathy was used as the measure of clinical outcome. For radiographic assessment, the type of OPLL, the maximum OPLL occupation ratio, the C2-C7 angle, and the segmental range of motion at the peak of OPLL (segmental ROM) were assessed. To elucidate the factors that are significantly associated with a poor clinical outcome after laminoplasty for K-line (+) OPLL, statistical analyses were conducted. RESULTS: The mean preoperative JOA score was 8.9 points and improved to 12.8 points after surgery. The recovery of JOA score was 47 ± 35%. Stepwise logistic regression following univariate analyses revealed that preoperative segmental ROM at the peak of OPLL is an independent factor associated with a poor outcome (p = 0.04, odds ratio = 1.15). CONCLUSIONS: Large preoperative segmental ROM at the peak of the OPLL is an independent factor that has significant impact on poor surgical outcome after laminoplasty for K-line (+) OPLL.

BACKGROUND: Central sleep apnea (CSA) due to occipitocervical compression myelopathy is an extremely rare condition. Here we report a case of surgical treatment for CSA due to occipitocervical compression myelopathy in a patient with Klippel-Feil syndrome. CASE DESCRIPTION: A 60-year-old man had become aware of a gradually progressive clumsiness and gait disturbance without any cause of injury 5 years before. He had complicated respiratory discomfort during sleep for the previous month and visited our hospital. Neurologic examination revealed severe myelopathy. Polysomnography showed CSA and Cheyne-Stokes respiration. Imaging findings showed C2-3 vertebral fusion and severe spinal cord compression caused by hypoplasia of the C1 posterior arch complicated by an anomaly of the vertebral artery. We diagnosed the patient with CSA due to occipitocervical compression myelopathy complicated by Klippel-Feil syndrome. After a simulation using a full-scale 3-dimensional model, resection of the C1 posterior arch and C4-5 laminoplasty was performed. After surgery, both clumsiness and gait disturbance gradually improved. Polysomnography 1 month after surgery showed that the CSA and the Cheyne-Stokes respiration disappeared. CONCLUSIONS: Although a recent report has indicated the cause of sleep apnea in patients with rheumatoid arthritis and occipitocervical disorders as obstructive sleep apnea, a significant improvement of CSA was observed with decompression surgery in this case. Appropriate surgical planning resulted in a favorable outcome.

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.

A 70-year-old male was referred to our hospital with lower limb muscle weakness and numbness of the left hand. The patient had previously been diagnosed seven years ago with lung cancer accompanied by central airway obstruction and had received chemoradiotherapy following placement of a metallic stent. Computed tomography (CT) scan revealed an osteolytic lesion which was adjacent to the fractured stent. T2-weighted magnetic resonance imaging (MRI) demonstrated high signal intensity in the disc space. The patient was diagnosed with spondylodiscitis and spinal epidural abscess related to the airway stent. Despite hemilaminectomy, laminectomy and long-term antibiotic therapy, the infection was uncontrolled. Moreover, osteolytic destruction and kyphotic deformity progressed. Removal of the airway stent was necessary; however, it was impossible because bronchial resection was required and the risk of mediastinal injury was considered to be high. The patient subsequently received palliative care. Long-term airway stenting can cause spondylodiscitis and spinal epidural abscess. Indications for the placement of metallic stents for malignant central airway obstruction should be carefully evaluated after considering the difficulty in removal and the long-term risk of severe complications. KEY POINTS: Significant findings of the study Long-term placement and fracture of the airway stent can cause spondylodiscitis and spinal epidural abscess. What this study adds The indication of placement of a metallic stent for malignant central airway obstruction should be considered with caution, especially if long-term survival can be expected.

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.

脊椎患者における神経学的所見や機能評価、認知機能の評価などリハビリテーションを進めるうえで知っておくべき代表的な評価法や認知機能評価について概説、さらには骨粗鬆症やサルコペニアなどを含む高齢者をとりまく問題点・特殊性についても述べた。脊椎疾患患者の神経症状を中心とした理学所見の評価の実際やSF-36、RMDQ、ODIやNDI、ならびに新旧JOAスコアなど、機能およびADL・QOL評価を行うための指標、および長谷川式に代表される認知機能評価は高齢者に対する有効な診療を行ううえでは重要かつ不可欠な評価である。本邦が突入した超高齢社会においては、臨床の最前線で運動器疾患に対峙する整形外科、リハビリテーション科をはじめ多分野の連携が重要となってくるものと考えられ、そのためには骨粗鬆症やそれに伴う疼痛、サルコペニアを含む体幹・四肢筋量の低下がもたらす影響とロコモティブシンドロームも念頭に置くことで、より総合的・学際的な運動器診療の実施が可能となる。(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)