稲毛 一秀

OBJECTIVE: It is important to develop an easy means of diagnosing lumbar foraminal stenosis (LFS) in a general practice setting. We investigated the use of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) to diagnose LFS in symptomatic patients. METHODS: Subjects included 13 cases (mean age, 72 years) with LFS, and 30 cases (mean age, 73 years) with lumbar spinal canal stenosis (LSCS) involving one intervertebral disc. The visual analogue scale score for low back pain and leg pain, the JOABPEQ were evaluated. RESULTS: Those with LFS had a significantly lower JOA score (p<0.001), while JOABPEQ scores (p<0.05) for lumbar dysfunction and social functioning impairment (p<0.01) were both significantly lower than the scores in LSCS. The following JOABPEQ questionnaire items (LFS vs. LSCS, p-value) for difficulties in: sleeping (53.8% vs. 16.6%, p<0.05), getting up from a chair (53.8% vs. 6.6%, p<0.001), turning over (76.9% vs. 40%, p<0.05), and putting on socks (76.9% vs. 26.6%, p<0.01) such as pain during rest, and signs of intermittent claudication more than 15 minutes (61.5% vs. 26.6%, p<0.05) were all significantly more common with LFS than LSCS. CONCLUSION: Results suggest that of the items in the JOABPEQ, if pain during rest or intermittent claudication is noted, LFS should be kept in mind as a cause during subsequent diagnosis and treatment. LFS may be easily diagnosed from LSCS using this established patient-based assessment method.

近年、腰椎の前方、側方固定術が低侵襲化され、lateral lumbar interbody fusion(LLIF)として広く普及するようになった。このLLIFの特徴は、前方の矯正力が強いため、椎間板性腰痛、腰椎すべり症、成人脊柱変形に応用されている。2012年から導入され、本邦では5,000件以上の手術が施行されてきた。本稿では、LLIFのなかでも、oblique lateral interbody fusion(OLIF)を用いた適応(椎間板性腰痛、化膿性脊椎炎、腰椎すべり症に対する間接除圧手術、脊柱変形に対する矯正手術)と手術手技について供覧したい。ただ、脊髄神経損傷、内臓損傷(腹膜、胸膜、大腸、尿管等)、血管損傷等の合併症も報告されており、十分注意すべきである。(著者抄録)

STUDY DESIGN: A retrospective radiological study on vascular anatomy. OBJECTIVE: The aim of this study was to evaluate the anatomical and radiological features of lumbar segmental arteries with respect to the surgical field of the oblique lateral interbody fusion (OLIF) approach by using magnetic resonance imaging (MRI). SUMMARY OF BACKGROUND DATA: OLIF surgery restores disc height and enables indirect decompression of narrowed spinal canals through an oblique lateral approach to the spine, by using a specially designed retractor. In a minimal surgical field, injuring segmental arteries can cause massive hemorrhage. METHODS: We reviewed 272 lumbar MRIs. In the sagittal images, the intersection of one-third of the anterior and median lines of the intervertebral disc (IVD) was considered the center of the virtually installed OLIF retractor. The cephalad/caudal distances from the center and branch angles of segmental arteries to the longitudinal axes of the aorta were measured to determine whether the segmental arteries run into the surgical area. Statistical significance was set at P < 0.05. RESULTS: The branch angles of segmental arteries were significantly acute (≤90°) in L1-L3 arteries and significantly blunt (>90°) in L4 and L5 arteries. The average distance to the center of the caudal adjacent IVD was significantly larger, and there were generally low possibilities for the existence of segmental arteries below half of the vertebral height, where the surgeons can install fixation pins with ease and safety. Among the lumbar segmental arteries, L5 showed specific characteristics with significant deviation, a four times (4.1% vs. L1-L3 segmental arteries) higher adjacency rate, and a two-fifth (38.6% vs. 100%) lower existence rate. CONCLUSION: Segmental arteries can be involved in the surgical field of OLIF especially in the lower lumbar spine level of L4 and L5 arteries, which can directly run across IVDs. L5 segmental arteries can also be iliolumbar arteries that have an abnormal trajectory by nature. LEVEL OF EVIDENCE: 4.

STUDY DESIGN: Animal model study. PURPOSE: The purpose of this study was to evaluate the histological variation in the injured muscle and production of calcitonin gene-related peptide in rats over time. OVERVIEW OF LITERATURE: Vertebral surgery has been reported to cause atrophy of the back muscles, which may result in pain. However, few reports have described the time series histological variation in the injured muscle and changes in the dominant nerve. METHODS: We used 30 male, 8-week-old Sprague-Dawley rats. The right and left sides of the paravertebral muscle were considered as the injured and uninjured sides, respectively. A 115 g weight was dropped from a height of 1 m on the right paravertebral muscle. Hematoxylin and eosin (H&E) staining of the muscle was performed 1-3 weeks after injury for histological evaluation. Fluoro-Gold (FG) was injected into the paravertebral muscle. The L2 dorsal root ganglia on both sides were resected 1, 2, and 3 weeks after injury, and immunohistochemical staining for calcitonin gene-related peptide was performed. RESULTS: H&E staining of the paravertebral muscle showed infiltration of inflammatory cells and the presence of granulation tissue in the injured part on the ipsilateral side 1 week after injury. Muscle atrophy occurred 3 weeks after injury, but was repaired via spontaneous replacement of muscle cells/fibers. In contrast, compared with the uninjured side, the percentage of cells double-labeled with FG and calcitonin gene-related peptide in FG-positive cells in the dorsal root ganglia of the injured side was significantly increased at each time point throughout the study period. CONCLUSIONS: These results suggest that sensitization of the dominant nerve in the dorsal root ganglia, which may be caused by cicatrix formation, can protract injured muscle pain. This information may be helpful in elucidating the underlying mechanism of persistent pain after back muscle injury.

STUDY DESIGN: Retrospective case series. PURPOSE: The purpose of this study was to examine changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a 10-year follow-up. OVERVIEW OF LITERATURE: Extreme lateral interbody fusion provides minimally invasive treatment of the lumbar spine; this anterior fusion without direct posterior decompression, so-called indirect decompression, can achieve pain relief. Anterior fusion may restore disc height, stretch the flexure of the ligamentum flavum, and increase the spinal canal diameter. However, changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a long follow-up have not yet been reported. METHODS: We evaluated 10 patients with L4 spondylolisthesis who underwent stand-alone anterior interbody fusion using the iliac crest bone. Magnetic resonance imaging was performed 10 years after surgery. The cross-sectional area (CSA) of the dural sac and the ligamentum flavum at L1-2 to L5-S1 was calculated using a Picture Archiving and Communication System. RESULTS: Spinal fusion with correction loss (average, 4.75 mm anterior slip) was achieved in all patients 10 years postsurgery. The average CSAs of the dural sac and the ligamentum flavum at L1-2 to L5-S1 were 150 mm2 and 78 mm2, respectively. The average CSA of the ligamentum flavum at L4-5 (30 mm2) (fusion level) was significantly less than that at L1-2 to L3-4 or L5-S1. Although patients had an average anterior slip of 4.75 mm, the average CSA of the dural sac at L4-5 was significantly larger than at the other levels. CONCLUSIONS: Spinal stability induced a lumbar ligamentum flavum change and a sustained remodeling of the spinal canal, which may explain the long-term pain relief after indirect decompression fusion surgery.

STUDY DESIGN: A retrospective multicenter survey. OBJECTIVE: To investigate the perioperative complications of oblique lateral interbody fusion (OLIF) surgery. SUMMARY OF BACKGROUND DATA: OLIF has been widely performed to achieve minimally invasive, rigid lumbar lateral interbody fusion. The associated perioperative complications are not yet well described. METHODS: The participants were patients who underwent OLIF surgery under the diagnosis of degenerative lumbar diseases between April 2013 and May 2015 at 11 affiliated medical institutions. The collected data were classified into intraoperative and early-stage postoperative (≤1 mo) complications. The intraoperative complications were then subcategorized into organ damage (neural, vertebral, vascular, and others) and other complications, mainly related to instrumental failure. The collected data were also divided and analyzed based on whether the surgeon was certified to perform the surgery and the incidence of complications in the early (April 2013-March 2014) and late stages (April 2014-May 2015) of OLIF introduction. RESULTS: In the 155 included patients, 75 complications were reported (incidence rate, 48.3%). The most common complication was endplate fracture/subsidence (18.7%), followed by transient psoas weakness and thigh numbness (13.5%) and segmental artery injury (2.6%). Almost all these complications were transient, except for three patients who had permanent damage: one had ureteral injury and two had neurological injury. Postoperative complications included surgical site infection (1.9%) and reoperation (1.9%). Whether the primary operator was experienced did not affect the incidence of complications. Regarding the introductory stage, the incidence of complications was 50% in the early stage and 38% in the late stage. CONCLUSION: The overall incidence of perioperative complications of OLIF surgery reached 48.3%, of which only 1.9% resulted in permanent damage. Our analysis based on surgeon experience indicated that the OLIF procedure could be performed without increasing incidence of complications, under the guidance of experienced supervisors. LEVEL OF EVIDENCE: 3.

We developed a new scaffold material-oriented collagen tubes (OCT)-and evaluated the potential of OCTs combined with basic fibroblast growth factor (bFGF) to repair of a 15 mm sciatic nerve defect in rats. The treatment groups consisted of OCT with adsorbed bFGF (OCT/bFGF group), OCT in phosphate-buffered saline (PBS) (OCT/PBS group), and a no-treatment group (Defect group). Functional evaluation of nerve regeneration was performed using the CatWalk system, and histological analyses of the defect sites were also performed. In rats treated with either OCT/bFGF or OCT/PBS, the walking function parameter of max contact area returned to normal levels by 4 weeks after grafting, and the regeneration of myelinated fibers was detected after 8 weeks. However, more regenerated myelinated fibers were observed in the OCT/bFGF group compared with the OCT/PBS group at 4 weeks. In addition, the max contact area and swing speed in the OCT/bFGF group were significantly recovered compared to the OCT/PBS and Defect groups at 8 weeks. Although the combination of bFGF and OCT was superior to OCT alone for nerve regeneration and functional recovery, the present findings demonstrate that OCT alone or in combination with bFGF accelerates nerve repair in a large peripheral nerve defect in rats. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 8-14, 2017.

BACKGROUND: Age-related sarcopenia may cause physical dysfunction. We investigated the involvement of sarcopenia in dropped head syndrome (DHS). METHODS: Our study subjects were ten elderly women with idiopathic DHS (mean age 75.1 years, range 55-89). Twenty age- and sex-matched volunteers (mean age 73.0, range 58-83) served as controls. We used a bioelectrical impedance analyzer (BIA) to analyze body composition, including appendicular skeletal muscle mass index (SMI; appendicular lean mass (kg)/(height (m))2). SMI <5.75 was considered diagnostic for sarcopenia. Cervical sagittal plane alignment: C2-7 sagittal vertical axis (SVA), C2-7 angle (C2-C7 A), and C2 slope (C2S) were also measured. We investigated sarcopenia prevalence in both groups, height, weight, BMI, lean mass arm, lean mass leg, lean mass trunk, appendicular lean mass, total lean mass, and SMI. In addition, we also examined the correlation between cervical spine alignment and SMI in DHS. RESULTS: Sarcopenia was observed at a high rate in DHS subjects: 70% compared to 25% of healthy controls. Height, weight, BMI, lean mass arm, lean mass leg, axial lean mass, appendicular lean mass, total lean mass, and SMI all had significantly lower values in the DHS group. In particular, total lean mass, lean mass arm, and lean mass trunk were considerably lower in the DHS group. There was no correlation noted between cervical spine alignment and SMI. CONCLUSIONS: Sarcopenia prevalence was high in the DHS group-70 versus 25% in the control group, suggesting the involvement of sarcopenia in DHS. In particular, axial lean mass and lean mass arm were markedly reduced in the DHS group. DHS is due to significant weakness of the neck extensor group, and chin-on-chest deformity occurs. Until the present, evaluation of DHS has been done using only MRI; no studies have systematically examined skeletal muscle mass. In the present study, muscle mass decrease was noted not only in the neck muscles but also throughout the entire body. Involvement of trunk and upper limb muscles in particular suggests a disuse atrophy of the upper body and spinal muscles. BIA can easily and systemically evaluate skeletal muscle mass. We expect it to contribute to further elucidating the pathogenesis of DHS.

BACKGROUND: Age-related sarcopenia can cause various forms of physical disabilities. We investigated how sarcopenia affects degenerative lumbar scoliosis (DLS) and lumbar spinal canal stenosis (LSCS). METHODS: Subjects comprised 40 elderly women (mean age 74 years) with spinal disease whose chief complaints were low back pain and lower limb pain. They included 15 cases of DLS (mean 74.8 years) and 25 cases of LSCS (mean age 72.9 years). We performed whole-body dual-energy X-ray absorptiometry (DXA) to analyze body composition, including appendicular and trunk skeletal muscle mass index (SMI; lean mass (kg)/height (m)2) and bone mineral density (BMD). A diagnostic criterion for sarcopenia was an appendicular SMI <5.46. To check spinal alignment, lumbar scoliosis (LS), sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), and vertebral rotational angle (VRA) were measured. Clinical symptoms were determined from the Japanese Orthopedic Association scores, low back pain visual analog scale, and Roland-Morris Disability Questionnaire (RDQ). Criteria for DLS were lumbar scoliosis >10° and a sagittal vertical axis (SVA) >50 mm. Sarcopenia prevalence, correlations between spinal alignment, BMD, and clinical symptoms with appendicular and trunk SMIs, and correlation between spinal alignment and clinical symptoms were investigated. RESULTS: DLS cases had significantly lower body weight, BMI, lean mass arm, and total lean mass than LSCS cases. Sarcopenia prevalence rates were 4/25 cases (16%) in LSCS and 7/15 cases (46.6%) in DLS, revealing a high prevalence in DLS. Appendicular SMIs were DLS 5.61 and LSCS 6.13 (p < 0.05), and trunk SMIs were DLS 6.91 and LSCS 7.61 (p < 0.01) showing DLS to have significantly lower values than LSCS. Spinal alignment correlations revealed the appendicular SMI was negatively correlated with PT (p < 0.05) and the trunk SMI was found to have a significant negative correlation with SVA, PT, LS, and VRA (p < 0.05). The trunk SMI was found to have a significant positive correlation with BMD (p < 0.05). As for clinical symptoms, RDQ was negatively correlated with appendicular SMI and positively correlated with PT (P < 0.05). CONCLUSIONS: Sarcopenia complications were noted in 16% of LSCS patients and a much higher percentage, or 46.6%, of DLS patients. Appendicular and trunk SMIs were both lower in DLS, suggesting that sarcopenia may be involved in scoliosis. The appendicular skeletal muscle was related to posterior pelvic tilt, while the trunk muscle affected stooped posture, posterior pelvic tilt, lumbar scoliosis, and vertebral rotation. Decreases in trunk muscle mass were also associated with osteoporosis. Moreover, RDQ had a negative correlation with appendicular skeletal muscle mass and a positive correlation with PT, suggesting that sarcopenia may be associated with low back pain as a result of posterior pelvic tilt. Our research reveals for the first time how sarcopenia is involved in spinal deformations, suggesting decreases in pelvic/lumbar support structures such as trunk and appendicular muscle mass may be involved in the progression of spinal deformities and increased low back pain.

BACKGROUND: Elderly female patients complaints of acute low back pain (LBP) may involve vertebral fracture (VF), among which occult VF (OVF: early-stage VF without any morphological change) is often missed to be detected by primary X-ray examination. The current study aimed to investigate the prevalence of VF and OVF and the diagnostic accuracy of the initial X-ray in detecting OVF. METHOD: Subjects were elderly women (>70 years old) complaining of acute LBP with an accurate onset date. Subjects underwent lumbar X-ray, magnetic resonance imaging (MRI), and bone mineral density (BMD) measurement at their first visit. The distribution of radiological findings from X-ray and magnetic resonance imaging (MRI) as well as the calculation of the prevalence of VF and OVF are investigated. RESULTS: The prevalence of VF among elderly women with LBP was 76.5% and L1 was the most commonly injured level. Among VF cases, the prevalence of OVF was 33.3%. Furthermore, osteoporotic patients tend to show increased prevalence of VF (87.5%). The predictive values in detecting VF on the initial plain X-ray were as follows: sensitivity, 51.3%; specificity, 75.0%; and accuracy rate, 56.7%. CONCLUSIONS: Acute LBP patients may suffer vertebral injury with almost no morphologic change in X-ray, which can be detected using MRI.

How aging affects the spinal cord at a molecular level is unclear. The aim of this study was to explore spinal cord aging-related proteins that may be involved in pathological mechanisms of age-related changes in the spinal cord. Spinal cords of 2-year-old and 8-week-old female Sprague-Dawley rats were dissected from the animals. Protein samples were subjected to 2-dimentional polyacrylamide gel electrophoresis followed by mass spectrometry. Screened proteins were further investigated with immunohistochemistry and Western blotting. Among the screened proteins, we selected α-crystallin B-subunit (αB-crystallin) and peripherin for further investigation because these proteins were previously reported to be related to central nervous system pathologies. Immunohistochemistry and Western blotting revealed significant upregulation of αB-crystallin and peripherin expression in aged rat spinal cord. Further exploration is needed to elucidate the precise mechanism and potential role of these upregulated proteins in spinal cord aging processes.

Spinal metastasis of differentiated thyroid cancer can have a favorable prognosis if radical surgery is performed. We encountered a case of spinal metastasis involving three anterior vertebral bodies at the posterior element fusion level and successfully achieved adequate stability by radical surgery involving only the anterior elements. A 67-year-old woman who had numbness and muscle weakness in the lower limbs caused by metastatic spinal tumor at the posterior element fusion level of L1-L3 vertebrae was treated with radical surgery of only the anterior element to gain stability. Similar situations may occur in cases involving other malignant tumor metastases or spinal primary tumors. If such a case occurs, this method could be useful in preventing metastasis to the posterior element.

Introduction: Oblique lateral interbody fusion (OLIF) can achieve recovery of lumbar lordosis (LL) in minimally invasive manner. The current study aimed to evaluate the location of lateral intervertebral cages during OLIF in terms of LL correction. Methods: The subjects were patients who underwent OLIF for lumbar degenerative diseases, including lumbar spinal stenosis, spondylolisthesis, and discogenic low back pain. Their clinical outcome was evaluated using visual analogue scale on lower back pain (LBP), leg pain and numbness. The following parameters were retrospectively evaluated on plain radiographic images and computed tomography scans before and at 1 year after OLIF: the intervertebral height, vertebral translation, and sagittal angle. The cage position was defined by equally dividing the caudal endplate into five zones (I to V), and its association with segmental lordosis restoration was analyzed. Subjects were also evaluated for a postoperative endplate injury. Results: Eighty patients (121 fused levels) with lumbar degeneration who underwent OLIF were included. There were no significant specific distribution in preoperative disc pathology such as disc angle, height, and translation. After OLIF, sagittal alignment was improved with an average correction angle of 3.8º at the instrumented segments in a level-independent fashion. All cases showed significant improvement in clinical outcomes, and had improvement in the radiological parameters (P<0.05). A detailed analysis of the cage position showed that the most significant sagittal correction and the most postoperative endplate injuries occurred in the farthest anterior zone (I). Cages with a 12-mm height were associated with more endplate injuries compared with shorter cages (8 or 10 mm). Conclusions: OLIF improves sagittal alignment with an average correction angle of 3.8º at the instrumented segments. We suggest that the optimal cage position for better lordosis correction and the fewest endplate injuries is zone II with a cage height of up to 10 mm.

PURPOSE: We examined duloxetine's effectiveness in the treatment of neuropathic pain in patients who were intolerant to continuous pregabalin administration. MATERIALS AND METHODS: The present study is a retrospective study of patients diagnosed with neuropathic pain with neuropathic leg pain as the chief complaint. We analyzed 20 cases in which pregabalin was changed to duloxetine because of adverse effects (16 cases) or treatment failure (4 cases). The incidence of adverse events after duloxetine administration was used as the primary endpoint, with the secondary endpoint being the leg pain level based on a numerical rating scale (NRS). RESULTS: The incidence of adverse events after starting duloxetine was 40%. Average leg pain scores measured on the NRS were 8.4±1.4, 6.4±1.4, and 4.1±2.0 at the time of the patients' first visit, pregabalin discontinuation, and after switching to duloxetine, respectively. A significant difference in NRS scores was found between the first visit and pregabalin discontinuation and also between pregabalin discontinuation and after the switch to duloxetine (p<0.05), indicating that pain decreases over time. Furthermore, NRS scores significantly declined between the patients' first visit and after the switch to duloxetine (p<0.05). The improvement in NRS score was 20±12.8% after pregabalin administration and 23±12.0% after duloxetine administration compared with baseline scores (no significant difference between pregabalin and duloxetine; p>0.05). CONCLUSION: When patients with neuropathic pain are unable to tolerate pregabalin because of adverse effects, changing the medication to duloxetine may be an option.

Much progress has been made in neuroimaging with Magnetic Resonance neurography and Diffusion Tensor Imaging (DTI) owing to higher magnetic fields and improvements in pulse sequence technology. Reports on lumbar nerve DTI have also increased considerably. Many studies have shown that the use of DTI in lumbar nerve lesions, such as lumbar foraminal stenosis and lumbar disc herniation, makes it possible to capture images of interruptions of tractography at stenotic sties, enabling the diagnosis of stenosis. DTI can also reveal significant decreases in fractional anisotropy (FA) with significant increases in apparent diffusion coefficient (ADC) values in compression lesions. FA values have higher accuracy than ADC values. Furthermore, strong correlations exist between FA values and indications of neurological severity, including the Japanese Orthopedic Association (JOA) score, the Oswestry Disability Index (ODI), and the Roland-Morris Disability Questionnaire (RDQ) in patients with lumbar disc herniation-induced radiculopathy. Most lumbar DTI has become 3T; 3T MRI has made it possible to take high-resolution DTI measurements in a short period of time. However, increased motion artifacts in the magnetic susceptibility effect lead to signal irregularities and image distortion. In the future, high-resolution DTI with reduced field-of-view may become useful in clinical applications, since visualization of nerve lesions and quantification of DTI parameters could allow more accurate diagnoses of lumbar nerve dysfunctions. Future translational studies will be necessary to successfully bring MR neuroimaging of lumbar nerve into clinical use.

Introduction: Osteoporosis is a pathological state with an unbalanced bone metabolism mainly caused by accelerated osteoporotic osteoclast activity due to a postmenopausal estrogen deficiency, and it causes some kinds of pain, which can be divided into two types: traumatic pain due to a fragility fracture from impaired rigidity, and pain derived from an osteoporotic pathology without evidence of fracture. We aimed to review the concepts of osteoporosis-related pain and its management. Methods: We reviewed clinical and basic articles on osteoporosis-related pain, especially with a focus on the mechanism of pain derived from an osteoporotic pathology (i.e., osteoporotic pain) and its pharmacological treatment. Results: Osteoporosis-related pain tends to be robust and acute if it is due to fracture or collapse, whereas pathology-related osteoporotic pain is vague and dull. Non-traumatic osteoporotic pain can originate from an undetectable microfracture or structural change such as muscle fatigue in kyphotic patients. Furthermore, basic studies have shown that the osteoporotic state itself is related to pain or hyperalgesia with increased pain-related neuropeptide expression or acid-sensing channels in the local tissue and nervous system. Traditional treatment for osteoporotic pain potentially prevents possible fracture-induced pain by increasing bone mineral density and affecting related mediators such as osteoclasts and osteoblasts. The most common agent for osteoporotic pain management is a bisphosphonate. Other non-osteoporotic analgesic agents such as celecoxib have also been reported to have a suppressive effect on osteoporotic pain. Conclusions: Osteoporotic pain has traumatic and non-traumatic factors. Anti-osteoporotic treatments are effective for osteoporotic pain, as they improve bone structure and the condition of the pain-related sensory nervous system. Physicians should always consider these matters when choosing a treatment strategy that would best benefit patients with osteoporotic pain.

著者らは「骨傷の明らかでない骨粗鬆症患者が訴え、時に慢性化し治療に難渋しうる腰背部痛」を骨粗鬆性疼痛と称している。閉経後女性の慢性腰痛に中枢神経系の変化が関与しているという報告や、転移性骨腫瘍痛の成因に破骨細胞の活性化が関与しているという報告もあり、骨粗鬆状態そのものが疼痛源となる可能性について検討する必要がある。椎体の神経支配と疼痛伝達機序、骨粗鬆性疼痛の発生機序、骨粗鬆性疼痛と骨粗鬆症治療薬との関係について述べた。

Fresh platelet-rich plasma (PRP) accelerates bone union in rat model. However, fresh PRP has a short half-life. We suggested freeze-dried PRP (FD-PRP) prepared in advance and investigated its efficacy in vivo. Spinal posterolateral fusion was performed on 8-week-old male Sprague-Dawley rats divided into six groups based on the graft materials (n = 10 per group): sham control, artificial bone (A hydroxyapatite-collagen composite) -alone, autologous bone, artificial bone + fresh-PRP, artificial bone + FD-PRP preserved 8 weeks, and artificial bone + human recombinant bone morphogenetic protein 2 (BMP) as a positive control. At 4 and 8 weeks after the surgery, we investigated their bone union-related characteristics including amount of bone formation, histological characteristics of trabecular bone at remodeling site, and biomechanical strength on 3-point bending. Comparable radiological bone union was confirmed at 4 weeks after surgery in 80% of the FD-PRP groups, which was earlier than in other groups (p < 0.05). Histologically, the trabecular bone had thinner and more branches in the FD-PRP. Moreover, the biomechanical strength was comparable to that of autologous bone. FD-PRP accelerated bone union at a rate comparable to that of fresh PRP and BMP by remodeling the bone with thinner, more tangled, and rigid trabecular bone.

近年、高齢化社会に伴い、腰椎すべり症、脊柱変形矯正固定術の手術が増加している。これらの手術には脊椎インストゥルメンテーションが必須であるが、骨粗鬆症による骨癒合不全、インプラントの緩みが問題となる。米国ではこれらを克服すべく骨癒合促進因子として、Bone morphogenetic proteinが使用されるが、本邦では認可を受けていない。近年、骨癒合促進効果のある骨粗鬆症薬剤としてParathyroid hormone(Teriparatide)が使用できることが可能となり、脊椎固定術に応用されてきた。我々の検討では、術前からテリパラチドを使用することで手術中のペディクルスクリューのトルク値の増強、術後のペディクルスクリューの緩みの減少、さらに骨癒合の促進効果が見出された。本稿では、テリパラチドを含めた薬剤の骨粗鬆症脊椎インストゥルメンテーション手術への可能性について記載したい。(著者抄録)

Background and Objective Cortical bone trajectory (CBT) spondylodesis is a novel screw fixation method in which screws are inserted through the pedicle in a caudal-medial to cephalad-lateral direction, providing a similar or more rigid spinal fixation compared with traditional pedicle screws. However, the traditional CBT technique requires invasive detaching and opening of the paraspinal muscle. In a small clinical prospective study we introduced a percutaneous CBT fixation technique by modifying the percutaneous pedicle screw (PPS) technique and evaluated the short-term outcome. Materials and Methods We enrolled 40 patients with lower back pain (LBP) and limb r;adicular pain with a diagnosis of spondylolisthesis who underwent transforaminal lumbar interbody fusion surgery. The patients were divided into two groups according to screw trajectory: the percutaneous CBT (pCBT) and the traditional PPS arms (20 patients in each). A consecutive group of 20 patients underwent traditional PPS, and the other underwent pCBT; dorsal spondylodesis was combined with transforaminal lumbar interbody fusion (TLIF) in both groups. Perioperative data such as operative time, blood loss, duration of fluoroscopy, and total incision length were investigated. Postoperative outcomes were evaluated using the visual analog scale (VAS) for LBP and leg pain at baseline, 1, 6, and 12 months. A p value < 0.05 was considered statistically significant. Results We observed no significant disadvantages in pCBT patients in perioperative and postoperative data compared with the PPS group. There were no complications. The pCBT patients showed a significantly shorter total incision length (p < 0.01) with a significantly shorter duration of fluoroscopy (p < 0.05). The postoperative VAS score was significantly improved in the pCBT group, especially 6 months after the surgery (p < 0.05). Conclusion The pCBT spondylodesis provided an outcome comparable with PPS fixation with a tendency for improvement 1 year postsurgery. This technique can be used in appropriate cases, combined with lumbar interbody fusion.

椎体は洞脊椎神経から分岐する感覚神経線維が内外に分布し、疼痛発生に関与する。椎体由来疼痛の発生機序には外傷や感染など外的要因に由来するものと、骨粗鬆症などによる内的要因によるものが挙げられる。動物モデルとして尾椎圧迫によるモデルが使用されるようになり、重力による圧迫変性の影響が擬似的に再現・評価されるようになった。骨粗鬆症などにおける椎体での持続的な炎症性変化と神経障害性変化が慢性腰痛の原因となり、それに対する治療が必要となる。(著者抄録)

近年、腰椎の前方、側方固定術が低侵襲化され、lateral lumbar interbody fusion(LLIF)として広く普及するようになった。このLLIFの特徴は、前方の矯正力が強いため、椎間板性腰痛、腰椎すべり症、成人脊柱変形に応用されている。2012年から導入され、本邦では5,000件以上の手術が施行されてきた。本稿では、LLIFのなかでも、oblique lateral interbody fusion(OLIF)を用いた腰椎すべり症に対する間接除圧手術、脊柱変形に対する矯正手術を供覧したい。ただ、脊髄神経損傷、内臓損傷(腹膜、胸膜、大腸、尿管等)、血管損傷などの合併症も報告されており、十分注意すべきである。(著者抄録)

INTRODUCTION: In this study we evaluated the relationships among the behavioral changes after muscle injury, histological changes, changes in inflammatory cytokines in the injured muscle, and changes in the sensory nervous system innervating the muscle in rats. METHODS: We established a model of muscle injury in rats using a dropped weight. Behavior was assessed using the CatWalk system. Subsequently, bilateral gastrocnemius muscles and dorsal root ganglia (DRGs) were resected. Muscles were stained with hematoxylin and eosin, and inflammatory cytokines in injured muscles were assayed. DRGs were immunostained for calcitonin gene-related peptide (CGRP). RESULTS: Changes of behavior and upregulation of inflammatory cytokines in injured muscles subsided within 2 days of injury. Repaired tissue was observed 3 weeks after injury. However, upregulation of CGRP in DRG neurons continued for 2 weeks after injury. CONCLUSION: These findings may explain in part the pathological mechanism of persistent muscle pain. Muscle Nerve 54: 776-782, 2016.

In patients with lower back and leg pain, lumbar foraminal stenosis (LFS) is one of the most important pathologies, especially for predominant radicular symptoms. LFS pathology can develop as a result of progressing spinal degeneration and is characterized by exacerbation with foraminal narrowing caused by lumbar extension (Kemp's sign). However, there is a lack of critical clinical findings for LFS pathology. Therefore, patients with robust and persistent leg pain, which is exacerbated by lumbar extension, should be suspected of LFS. Radiological diagnosis is performed using multiple radiological modalities, such as magnetic resonance imaging, including plain examination and novel protocols such as diffusion tensor imaging, as well as dynamic X-ray, and computed tomography. Electrophysiological testing can also aid diagnosis. Treatment options include both conservative and surgical approaches. Conservative treatment includes medication, rehabilitation, and spinal nerve block. Surgery should be considered when the pathology is refractory to conservative treatment and requires direct decompression of the exiting nerve root, including the dorsal root ganglia. In cases with decreased intervertebral height and/or instability, fusion surgery should also be considered. Recent advancements in minimally invasive lumbar lateral interbody fusion procedures enable effective and less invasive foraminal enlargement compared with traditional fusion surgeries such as transforaminal lumbar interbody fusion. The lumbosacral junction can cause L5 radiculopathy with greater incidence than other lumbar levels as a result of anatomical and epidemiological factors, which should be better addressed when treating clinical lower back pain.

STUDY DESIGN: Retrospective case series. PURPOSE: To examine the efficacy of TachoSil for vessel injury in 6 patients who underwent anterior lumbar fusion surgery (ALF). OVERVIEW OF LITERATURE: ALF for the lumbar spine has a high rate of success, although intraoperative concerns and iatrogenic complications are known, and injury of a major vessel is sometimes a complication. The efficacy of TachoSil, a fibrin-based hemostat, has been reported for several types of surgery; however, use of TachoSil for ALF surgery has not been described. Here, we report on the efficacy of TachoSil in 6 patients, who underwent ALF after vascular surgeons having difficulty in repairing vessels. METHODS: Two man and 4 women with average age of 50.8±10.9 (mean±standard deviation) were diagnosed with a vertebral tumor (2 patients), L4 degenerative spondylolisthesis (2 patients), and L5 spondylolytic spondylolisthesis (2 patients) and underwent ALF. The blood vessels injured included the common iliac vein in 2 patients and a branch of a segmental artery from the aorta in 4 patients. We consulted a vascular surgeon to suture or repair the vessels during surgery, and although the vascular surgeon attempted to address the injuries, suturing or repair was not possible in these cases. For this reason, we used TachoSil to repair the injury in the vessels walls or to stop the bleeding. RESULTS: Time to pressure hemostasis using TachoSil was 34±12 minutes, and total blood loss was 1,488±1,711 mL. Nevertheless, all vessel injuries were controlled by the use of TachoSil. CONCLUSIONS: We recommend the use of TachoSil for vessel injuries that vascular surgeons cannot suture or repair during ALF surgery.

STUDY DESIGN: Experimental animal study. PURPOSE: We aimed to determine the optimal dose of a single direct injection of the tumor necrosis factor (TNF)-α inhibitor, etanercept, by using the rat model of degenerative intervertebral disc from injury. OVERVIEW OF LITERATURE: The pain-related peptide expression was suppressed in the etanercept (100 µg and 1,000 µg)-administered groups in a dose-dependent manner. METHODS: The neurotracer FluoroGold (FG) was applied to the surfaces of L4/5 discs to label their innervating dorsal root ganglion (DRG) neurons (n=50). Ten rats were included in the nonpunctured disc sham surgery control group, whereas the other 40 were included in the experimental group in which intervertebral discs were punctured with a 23-gauge needle. Saline or etanercept (10 µg, 100 µg, or 1,000 µg) was injected into the punctured discs (n=10 for each treatment). After 14 days of surgery, DRGs from L1 to L6 were harvested, sectioned, and immunostained for calcitonin gene-related peptide (CGRP). The proportion of FG-labeled CGRP-immunoreactive DRG neurons was evaluated in all the groups. RESULTS: There were no significant differences between the puncture+saline group and the puncture+10-µg etanercept group (p >0.05). However, a significant decrease in the percentage of FG and CGRP double-positive cells in FG-positive cells was observed in the etanercept (100 µg and 1,000 µg)-administered groups in a dose-dependent manner (p <0.05). CONCLUSIONS: When a low dose of the TNF-α inhibitor (10 µg of etanercept) was directly administered to the rat intervertebral disc in the rat model of degenerative intervertebral disc from injury, no suppressive effect on the pain-related peptide expression was observed. However, when a higher dose of etanercept (100 µg and 1,000 µg) was administered, the pain-related peptide expression was suppressed in a dose-dependent manner.