稲毛 一秀

BACKGROUND: Several authors have reported favorable results in low back pain (LBP) for patients with lumbar disc herniation (LDH) treated with discectomy. However, detailed changes over time in the characteristics and location of LBP before and after discectomy for LDH remain unclear. To clarify these points, we conducted an observational study to determine the detailed characteristics and location of LBP before and after discectomy for LDH, using a detailed visual analog scale (VAS) bilaterally. METHODS: We included 65 patients with LDH treated by discectomy in this study. A detailed VAS for LBP was administered with the patient under 3 different conditions: in motion, standing, and sitting. Bilateral VAS was also administered (affected versus opposite side) for LBP, lower extremity pain (LEP), and lower extremity numbness (LEN). The Oswestry Disability Index (ODI) was used to quantify clinical status. Changes over time in these VAS and ODI were investigated. Pfirrmann grading and Modic change as seen by magnetic resonance imaging (MRI) were reviewed before and 1 year after discectomy to determine disc and endplate condition. RESULTS: Before surgery, LBP on the affected side while the patients were in motion was significantly higher than LBP while they were sitting (p = 0.025). This increased LBP on the affected side in motion was improved significantly after discectomy (p < 0.001). By contrast, the residual LBP while sitting at 1 year after surgery was significantly higher than the LBP while they were in motion or standing (p = 0.015). At 1 year following discectomy, residual LBP while sitting was significantly greater in cases showing changes in Pfirrmann grade (p = 0.002) or Modic type (p = 0.025). CONCLUSIONS: Improvement of LBP on the affected side while the patient is in motion suggests that radicular LBP is improved following discectomy by nerve root decompression. Furthermore, residual LBP may reflect increased load and pressure on the disc and endplate in the sitting position.

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.

PURPOSE: To clarify the impact of anchor type at upper instrumented vertebra (UIV) on postoperative shoulder imbalance in patients with Lenke type 1 adolescent idiopathic scoliosis (AIS) who underwent posterior spinal fusion. METHODS: Subjects were 81 patients with Lenke type 1 AIS who underwent posterior spinal fusion between 2004 and 2013. Twenty-five patients agreed to participate in the study. We divided the patients into two groups: Hook group (15 patients with hooks at UIV who underwent surgery between 2004 and 2011) and PS group (ten patients with pedicle screws at UIV who underwent surgery between 2012 and 2013). To evaluate shoulder balance, first thoracic vertebra tilt angle (T1 tilt), clavicle angle (CA), and radiographic shoulder height (RSH) were measured. RESULTS: There were no significant differences in preoperative T1 tilt, CA, or RSH between the both groups. The postoperative 1-week, 2-year, and most recently observed T1 tilts were significantly smaller in the Hook group than in the PS group. There were no significant differences in postoperative 1-week, 2-year, and most recently observed CAs between the two groups. Although there were no significant differences in 1-week postoperative RSH between the groups, the 2-year postoperative RSH was significantly smaller in the Hook group than in the PS group. The most recently observed RSH tended to be smaller in the Hook group than in the PS group, but the difference was not significant. CONCLUSIONS: In the PS group, poor shoulder balance remained over the long term. The hooks at UIV adjusted postoperative shoulder balance.

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.

Introduction: In the aging society, fragility fracture of the pelvis (FFP) has become a problem. Although strong and minimally invasive fixation is required in FFP surgery, reports on relevant surgical results are scarce. Crab-shaped fixation (CSF) is a spinopelvic fixation that involves reconstruction of the posterior pelvic ring using spinal instrumentation. This study aimed to evaluate the walking ability and perioperative complications of patients who underwent CSF for FFP. Methods: We included patients diagnosed with unstable FFPs, including sacral fracture, who required hospitalization. Demographic data, such as age, sex, bone mineral density, and Rommens classification, were evaluated. Surgical findings included estimated blood loss, operation time, and perioperative complications. The improvement in postoperative walking ability was evaluated based on the length of the postoperative period before the initiation of walker training and whether walking aids were required at 6 months post-surgery, compared with those who received conservative treatment for FFP. Results: Our study included 6 cases that received CSF and 16 cases that received conservative treatment, in which all were females and presented with sacral fractures. The average age of the surgical patients, the operation time, and the estimated blood loss were 79.5±14.7 years, 180.7±28.7 min, and 124.2±29.4 mL, respectively. The average length of the postoperative period prior to the initiation of walker training was 10.8±12.3 days, which was significantly shorter than that of conservative treatment. With regard to perioperative complications, poor reduction of fracture dislocation was observed in one case as well as surgical site infection in another case, but the walking ability improved in all cases. Conclusions: We evaluated the results of the posterior pelvic ring reconstruction with CSF for patients with vertically unstable FFPs, including sacral fractures. CSF is minimally invasive and would be useful as it allowed walker training during the early postoperative period, which improved patients' walking ability even during the in situ pelvic ring reconstruction.

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.

Introduction: The purpose of the present study was to determine, in a mid-term follow-up 5 years or more after surgery, the forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and expiratory flow in patients with adolescent idiopathic scoliosis (AIS) who underwent posterior spinal fusion (PSF) with or without thoracoplasty. Methods: The subjects were 134 patients with AIS who underwent PSF between 2004 and 2013. Forty-five patients agreed to participate in the study. We divided the patients into two groups as follows: 24 patients who underwent PSF with thoracoplasty from 2004 to 2010 in the TP group and 21 patients who underwent PSF without thoracoplasty from 2011 to 2013 in the non-TP group. We evaluated whole spine X-ray imaging and pulmonary function tests (PFTs) in these patients. PFTs measured FVC, FEV1, peak expiratory flow (PEF), maximum expiratory flow at 50% FVC (V50), maximum expiratory flow at 25% FVC (V25), and the ratio of V50 to V25 (V50/V25). Results: The main thoracic curves were 53.6 ± 10.1° before surgery, 19.8 ± 7.6° 1 week after surgery, 22.3 ± 8.3° 2 years after surgery, and 23.3 ± 7.6° at the most recent observation. Compared with preoperative values, FVC, FEV1, and % FEV1 were improved significantly at the most recent observation. No significant difference was observed between % FVC before surgery and at the most recent observation. Compared with preoperative values, PEF, V50, and V25 were improved significantly at the most recent observation. V50/V25 did not change significantly. The changes in PFT values in the TP group and the non-TP group were compared. No significant differences were observed in FVC, % FVC, FEV1, % FEV1, PEF, V50, or V25. Conclusions: Regardless of whether thoracoplasty was performed or not, FVC, FEV1, and expiratory flow were improved 5 years or later after PSF.

Introduction: There are few reports on body composition, particularly muscle mass, in patients with adolescent idiopathic scoliosis (AIS). The purpose of this study was to measure body composition including muscle mass and estimated bone mass of patients with AIS using bioelectrical impedance analysis (BIA) and to clarify the relationship between the degree of scoliosis and body composition. Methods: The subjects were 210 girls (mean age 14.0 years, range 10-18 years) whose body composition was evaluated using BIA (Tanita MC-780). Body mass index (BMI), percent body fat (%BF), lean muscle mass index (LMI: muscle mass/height^2), and estimated bone mass index (eBoneMI: estimated bone mass/height^2) were determined by age and compared with those of previous reports. We divided 111 subjects whose bone maturation was complete into two groups for comparison of body composition metrics: those with Cobb angle <40° (moderate scoliosis group) and those with Cobb angle ≥40° (severe scoliosis group). The relationships between Cobb angle and each body composition parameter were evaluated. Results: Age-adjusted BMI, %BF, and LMI tended to be low at all ages compared with means for the healthy Japanese population as previously reported. BMI, LMI, and eBoneMI were significantly lower in the severe scoliosis group compared with those in the moderate scoliosis group (p<0.05). In addition, all BMI, LMI, and eBoneMI were weakly correlated with Cobb angle (r= -0.20, -0.26, and -0.24). Conclusions: On the basis of the results of this study, patients with AIS are thinner, with lower BMI, %BF, and LMI compared with healthy girls of the same age. Furthermore, factors such as lower BMI, lower muscle mass, and lower estimated bone mass were correlated with progressive scoliosis.

Introduction: Platelet-rich plasma (PRP) is drawing attention as a substance that can promote bone formation. The growth factors present in PRP are stable for a long time after freeze-drying. However, the effects of PRP are inconsistent, and its effects on bone union in spinal surgery remain controversial. The immortalized megakaryocyte cell lines (imMKCLs) derived from human-induced pluripotent stem cells (hiPSCs) have been developed to produce numerous stable and clinically functional platelets. In this study, growth factors present in freeze-dried hiPSC-derived imMKCLs and platelets (iPS-MK/Plts) were evaluated, and their ability to promote bone formation was examined using a rat lumbar artificial bone grafting model. Methods: We prepared freeze-dried iPS-MK/Plts and quantified their growth factors by enzyme-linked immunosorbent assays. Surgical grafting of artificial bone to the lumbar transverse processes was performed in 8-week-old female rats, which were divided into two groups: artificial bone graft (control) and artificial bone graft plus freeze-dried iPS-MK/Plts (iPS group). Transplantation was performed only on the left side. Eight weeks after the surgery, we captured computed tomography images and compared bilateral differences in the bone volume of the graft site in each rat. We also compared the left side/right side bone volume ratio between the two groups. Results: The freeze-dried iPS-MK/Plts contained numerous growth factors. While there was no significant increase in bone volume on the transplanted side than that on the non-grafted side in the control group, bone volume significantly increased on the transplanted side in the iPS group, as evidenced by augmented mean left/right bone volume ratio of the iPS group compared with that of the control group. But the new bone observed in the iPS group was histologically normal. Conclusions: Freeze-dried hiPSC-derived MKCLs and platelets contain several stable growth factors and have the potential for promoting new bone formation.

＜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.

＜文献概要＞畳み込みニューラルネットワーク(convolutional neural network;CNN)の鑑別能を判断するため,CNNを用いたMRIによる神経鞘腫と髄膜腫の鑑別を行い,2人の放射線専門医の鑑別能と比較した。感度,特異度,正確度について比較したところ,CNNの鑑別能は放射線専門医と同等に良好であった。本稿では,この結果について考察した。※本稿は文献1の要約である。詳細なデータについては文献1を参照されたい。

これまでカップ設置の指標として用いられてきたsafe zoneであるが、safe zoneに設置されても脱臼が一定数発生していることが近年報告されるなど、その指標としての有効性が疑問視されている。今回、当院で片側THA(人工股関節置換術)を施行しsafe zoneにカップを設置した変形性股関節症40例(女性34例、男性6例、平均年齢59歳)の術後1年時のカップアライメントと動的なインピンジメントによる脱臼リスクをX線像により評価した。その結果、仰臥位においてsafe zoneにカップが設置されていても動的なインピンジメントの予測は困難で、動的な要因も含めインピンジメントを予防するには従来のsafe zoneに代わる新たな指標が必要と考えられた。

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.