Increasing Incidence of Degenerative Spinal Diseases in Japan during 25 Years: The Registration System of Spinal Surgery in Tohoku University Spine Society.

Spinal disorders affect mainly older people and cause pain, paralysis and/or deformities of the trunk and/or extremities, which could eventually disturb locomotive functions. For ensuring safe and high-quality treatment of spinal disorders, in 1987, the Tohoku University Spine Society (TUSS) was established by orthopedic departments in Tohoku University School of Medicine and its affiliated hospitals in and around Miyagi Prefecture. All spine surgeries have been enrolled in the TUSS Spine Registry since 1988. Using the data from this registration system between 1988 and 2012, we demonstrate here the longitudinal changes in surgical trends for spinal disorders in Japan that has rushed into the most advanced "aging society" in the world. In total, data on 56,744 surgeries were retrieved. The number of spinal surgeries has annually increased approximately 4-fold. There was a particular increase among patients aged ≥ 70 years and those aged ≥ 80 years, with a 20- to 90-fold increase. Nearly 90% of the spinal operations were performed for degenerative disorders, with their number increasing approximately 5-fold from 705 to 3,448. The most common disease for surgery was lumbar spinal stenosis (LSS) (35.9%), followed by lumbar disc herniation (27.7%) and cervical myelopathy (19.8%). In 2012, approximately half of the patients with LSS and cervical myelopathy were ≥ 70 years of age. In conclusion, the number of spinal operations markedly increased during the 25-year period, particularly among older patients. As Japan has a notably aged population, the present study could provide a near-future model for countries with aging population.

New diagnostic support tool for patients with leg symptoms caused by lumbar spinal stenosis and lumbar intervertebral disc herniation: A self-administered, self-reported history questionnaire.

BACKGROUND: There are no diagnostic support tools composed of a simple, single-sheet, self-administered, self-reported history questionnaire (SSHQ) for patients with leg symptoms caused by either lumbar spinal stenosis (LSS) or lumbar disc herniation (LDH), at the same time, can discriminate the two diseases. METHODS: We conducted retrospective and prospective derivation studies and a prospective validation study. Based on data from 137 patients with LSS and 206 with LDH, we identified key prediction factors to establish the diagnosis of LSS and LDH, which became the basis of a temporary SSHQ. Next, we performed a prospective derivation study in which 296 patients with LSS or LDH completed preoperatively this temporary SSHQ. After univariate and multivariate analyses of each question, questions on both diseases in addition to age factor were selected, providing the final version of the SSHQ. A validation study was subsequently performed with 342 consecutive patients with leg symptoms. The sensitivity, specificity and likelihood ratio of this SSHQ were calculated to determine the cut-off points for LSS and LDH. RESULTS: A SSHQ with 15 questions was developed from retrospective and prospective derivation studies. The score of each question was weighted based on the multivariate analysis and then, it was approximated to integer value. According to assessment of the discriminatory performance of the clinical prediction rule of the SSHQ, the cut-off point for LSS was ≥13 and that for LDH was ≥11. The sensitivity, specificity, and positive and negative likelihood ratios of this SSHQ at those cut-off points were, respectively, 92.7%, 84.7%, 6.07, and 0.09 for LSS, and 91.0%, 85.2%, 6.15, and 0.11 for LDH. CONCLUSIONS: This is the first report of a diagnostic support tool for patients with LSS- or LDH-induced leg symptoms combined in a single SSHQ that could help establish diagnosis of the two diseases in the daily clinical practice.

Are T1-Weighted Three-Dimensional Magnetic Resonance Images Inferior to T2-Weighted Images for Diagnosing Lumbar Foraminal Stenosis in the Fifth Lumbar Nerve Root? A Prospective, Comparative Study in Identical Patients.

Introduction: Imaging analysis of foraminal stenosis in the fifth lumbar (L5) nerve root remains to be a challenge because of the anatomical complexity of the lumbosacral transition. T2-weighted three-dimensional (3D) magnetic resonance images (MRI) have been dominantly used for diagnosis of lumbar foraminal stenosis, while the reliability of T1-weighted images (WI) has also been proven. In this study, we aim to compare the reliability and reproducibility of T1- and T2-weighted 3D MRI in diagnosing lumbar foraminal stenosis (LFS) of the L5 nerve root. Methods: In this study, 39 patients with unilateral L5 radiculopathy (20 had L4-L5 intracanal stenosis; 19 had L5-S foraminal stenosis) were enrolled, prospectively. T1- and T2-weighted 3D lumbar MRI were obtained from each patient. T1WI and T2WI were blinded and then separately reviewed twice by four examiners randomly. The examiners were instructed to answer the side of LFS or absence of LFS. The correct answer rate, sensitivity, specificity, and area under the curve were analyzed and compared between T1WI and T2WI. Also, intra- and interobserver agreements were calculated using kappa (κ)-statistics and compared in the same manner. Results: The average correct answer rate, sensitivity, specificity, and area under the curve of the T1WI/T2WI were 84.6%/80.1%, 82.9%/80.3%, 86.3%/81.3%, and 0.846/0.801, respectively. The intraobserver κ-values of the four examiners ranged from 0.692 to 0.916 (average: 0.762) and from 0.669 to 0.801 (average: 0.720) for T1WI and T2WI, respectively. The interobserver κ-values calculated in a round-robin manner (24 combinations in total) ranged from 0.544 to 0.790 (average: 0.657) and from 0.524 to 0.828 (average: 0.652), respectively. Conclusions: As per our findings, T1- and T2-weighted 3D MRI were determined to have nearly equivalent reliability and reproducibility in terms of diagnosing LFS of the L5 nerve root.

Rate of spinal surgery in a rapidly aging society: the 27-year changes in Miyagi prefecture, Japan.

BACKGROUND: Japan has had a rapidly aging population during the past 30 years. This study aimed to investigate longitudinal changes in the surgical rate for spinal disorders in Miyagi Prefecture (2.35 million inhabitants) with a similar population composition to Japan. METHODS: Data of spinal surgeries were collected using the spine registry by Tohoku University Spine Society. Data on the annual number of spinal surgeries between 1988 and 2014 of all populations, in those aged ≥65 years old, in those aged ≥75 years old, and for each pathology were collected. The annual surgical rate per 100,000 inhabitants was calculated. RESULTS: The surgical rate in 2010-2014 in total, at ≥65 years old, and at ≥75 years old showed 3.2-, 3.8- and 7.1-fold increases, respectively, compared with that in 1988-1989. Degenerative spinal disorders, spinal trauma and pyogenic spondylitis markedly increased, while metastatic spinal tumor and tuberculous spondylitis decreased over time. The surgical rate at ≥75 years with lumbar spinal stenosis showed a 12.6-time increase. CONCLUSIONS: During a rapid period of aging, the rate of spinal surgeries has markedly increased, particularly, that for degenerative disorders. This is the first report on the long-term longitudinal changes in the rate of spinal surgery.

Sagittal alignment changes after thoracic laminectomy in adults.

OBJECT: The increased kyphosis after thoracic laminectomy in adult patients was retrospectively evaluated and various factors affecting this spinal deformity were analyzed. METHODS: The authors conducted a retrospective study of 58 cases in which laminectomy was performed and more than half of the facet joints were left intact. The study group included 44 men (mean age 59 years) and 14 women (mean age 61 years) with thoracic myelopathy due to ossifications of the ligamentum flavum and/or the posterior longitudinal ligament or due to posterior bone spurs. Patients were followed up for a minimum of 2 years. Their neurological condition was evaluated using the Japanese Orthopaedic Association (JOA) scale (a full score is 11), and the magnitude of local kyphosis in the laminectomized area was determined using the Cobb angle method. RESULTS: The mean preoperative JOA score was 5.4; the mean postoperative score was 8.3. No relationship was found between postoperative JOA score and increased kyphotic angle. The mean preoperative kyphotic angle was 7.0 degrees . The mean postoperative kyphotic angle was 10.8 degrees . Thus local kyphosis in the treated area increased by only 3.8 degrees . The mean increase in kyphosis per spinal segment, calculated by dividing the kyphotic angle of the surgically decompressed area by the number of resected laminae, was 1.9 degrees . Female patients with >or= 3-level laminectomies showed a significant increase of kyphosis in both the laminectomized area and each spinal segment. CONCLUSIONS: The increase in kyphosis after thoracic laminectomy is not large and thus spinal fusion is usually not necessary. In cases involving female patients who undergo long-segment laminectomies, however, careful radiographic follow-up is recommended.

Spinal dumbbell tumors: an analysis of a series of 118 cases.

OBJECT: The authors analyzed a series of 118 cases of spinal dumbbell tumors to elucidate the feature of the tumors. METHODS: Of 674 cases of spinal cord tumors, the incidence of dumbbell tumors was studied. The tumors were analyzed, and the authors focus on the distribution of age and sex, the pathological diagnoses, their locations, Eden classification, and the surgical methods used. RESULTS: The incidence of dumbbell tumors was 18%. The mean patient age was 43 years, which was younger than that for all spinal cord tumors (mean 50 years). There were 11 patients younger than 10 years of age. The rate of dumbbell tumors in the cervical spine was significantly higher than that of all spinal cord tumors. Fifteen (18%) of the 81 schwannomas were observed in the C-2 nerve root, thus having a higher incidence than those in the other nerve roots. In 99 cases (84%), the tumors were removed through a hemilaminectomy with or without a facetectomy and posterior fusion. Of 118 cases, 69% of the tumors were schwannomas, and malignant tumors were found in 10 cases (8.5%). Seven (64%) of 11 patients younger than 10 years of age had malignant tumors. Three patients older than 10 years of age had malignant tumors, thus accounting for 2.8% of the 107 older patients. CONCLUSIONS: The incidence of dumbbell tumors was 18%, and they are not uncommon. Malignant dumbbell tumors were more common in children younger than 10 years of age than in older patients.

Possible oncogenic potential of DeltaNp73: a newly identified isoform of human p73.

p73, a recently identified gene highly homologous to p53, can transactivate p53 target genes and induce apoptosis. Here we report the identification of an NH(2)-terminal truncated isoform of human p73, DeltaNp73, which is capable of suppressing p53- and p73-dependent transactivation. We speculate that this suppression is achieved by competing for the DNA binding site in the case of p53 and by direct association in the case of TAp73. Expression of DeltaNp73 in cancer cell lines also inhibited suppressive activity of p53 and TAp73 in colony formation, implying possible involvement of DeltaNp73 in oncogenesis by inhibiting the tumor-suppressive function of p53 and TAp73. Also reported is the identification of TAp73eta, a new member of the COOH-terminal truncated isoform of p73 and tissue-specific expression of these isoforms, along with other previously identified p73 isoforms.

Ossification of transverse ligament of atlas causing cervical myelopathy: a case report and review of the literature.

A case of ossification of transverse ligament of atlas (TLA) is reported. A 76-year-old female suffered from a transverse type myelopathy was successfully treated by posterior decompression. Dynamic lateral plain radiographs showed irreducible atlantoaxial subluxation (AAS). A computed tomogram revealed ossified mass compatible to ossification of TLA. Coalition of the atlantooccipital joints and osteoarthritis of the atlantoaxial joints with degenerated dens was also revealed. Magnetic resonance imaging showed compressed spinal cord at C1 level by the ossification of TLA and AAS. We suggest a mechanism of ossification of TLA as follows: hypertrophied dens and stress to the atlantoaxial joints caused by coalition of atlantooccipital joints could make forward shift of atlas leading to irreducible AAS, and continuous tension given to TLA from irreducible AAS would result in hypertrophied and ossification of TLA.

Myolysis of the erector spinae muscles as the cause of scoliosis in osteoid osteoma of the spine.

STUDY DESIGN: A case of an osteoid osteoma at the lower thoracic spine with scoliosis is reported. OBJECTIVES: To suggest that myolysis of the erector spinae muscles reflected by signal abnormalities on magnetic resonance images causes back pain, protective muscle contraction, and scoliosis. SUMMARY OF BACKGROUND DATA: Osteoid osteomas of the spine are frequently accompanied by scoliosis. The proposed mechanism of the scoliosis has been explained as a postural adaptation of the spine through predominant muscle spasm on the concave side. METHODS: The history of the patient and radiologic, magnetic resonance imaging, and histologic findings of the peritumoral area were reviewed. RESULTS: Magnetic resonance images showed signal abnormalities on muscles surrounding the tumor, and use of gadopentetate dimeglumine resulted in an enhancement. The microscopic examination of the erector spinae muscles that demonstrated high intensities on T2-weighted images showed derangement or destruction of the muscle fibers and replacement of the muscle fibers with fat tissue and infiltrating inflammatory cells. CONCLUSION: These findings were interpreted as those of myolysis. The suggested mechanism of the induction of scoliosis by the present osteoid osteoma is that the unaffected iliocostalis and quadratus lumborum muscles on the tumor side predominantly contracted over those on the opposite side to decrease the tension of the erector spinae muscles involved in myolysis, thereby producing a functional scoliosis.