Takashi Tsuji

STUDY DESIGN: Prospective, multicenter, nationwide study. OBJECTIVE: To investigate perioperative complications and risk factors in surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL) using data from the registry of the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. SUMMARY OF BACKGROUND DATA: There is no prospective multicenter study of surgical complications and risk factors for T-OPLL, and previous multicenter retrospective studies have lacked details. METHODS: Surgical methods, preoperative radiographic findings, pre- and postoperative thoracic myelopathy (Japanese Orthopaedic Association [JOA] score), prone and supine position test (PST), intraoperative ultrasonography, and intraoperative neurophysiological monitoring (IONM) were investigated prospectively in 115 cases (males: 55, females: 60, average age 53.1 y). Factors related to perioperative complications and risk factors for postoperative motor palsy were identified. RESULTS: Posterior decompression and fusion with instrumentation with or without dekyphosis was performed in 85 cases (74%). The JOA recovery rate at 1 year after surgery in all cases was 55%. Motor palsy occurred postoperatively in 37 cases (32.2%), with a mean recovery period of 2.7 months. A long recovery period for postoperative motor palsy was significantly associated with a high number of T-OPLL levels (P < 0.0001), lower preoperative JOA score (P < 0.05), and greater estimated blood loss (P < 0.05). Perioperative complications or postoperative motor palsy were significantly related to a higher number of T-OPLL levels, comorbid ossification of ligamentum flavum rate, lower preoperative JOA score, higher preoperative positive PST rate, more surgical invasiveness, a lower rate of intraoperative spinal cord floating in ultrasonography, and higher rate of deterioration of IONM. CONCLUSION: This study firstly demonstrated the perioperative complications with high postoperative motor palsy rate in a nationwide multicenter prospective study. Surgical outcomes for T-OPLL should be improved by identifying and preventing perioperative complications with significant risk factors. LEVEL OF EVIDENCE: 3.

BACKGROUND: Few studies have addressed in detail long-term degenerative changes in the cervical spine. In this study, we evaluated the progression of degenerative changes of the cervical spine that occurred over a 20-year period in an originally healthy cohort. We also sought to clarify the relationship between the progression of cervical degenerative changes and the development of clinical symptoms. METHODS: For this prospective follow-up investigation, we recruited 193 subjects from an original cohort of 497 participants who had undergone magnetic resonance imaging (MRI) of the cervical spine between 1993 and 1996. The subjects were asked about the presence or absence of cervical spine-related symptoms. Degenerative changes of the cervical spine were assessed on MRI using an original numerical grading system. The relationship between the progression of degenerative changes and the onset of clinical symptoms was evaluated by logistic regression analysis. RESULTS: Degeneration in the cervical spine was found to have progressed in 95% of the subjects during the 20-year period. The finding of a decrease in signal intensity of the intervertebral disc progressed in a relatively high proportion of the subjects in all age groups and occurred with similar frequency (around 60%) at all intervertebral disc levels. The rate of progression of other structural failures on MRI increased with age and was highest at C5-C6. The progression of foraminal stenosis was associated with the onset of upper-limb pain (odds ratio, 4.71 [95% confidence interval, 1.02 to 21.7]). CONCLUSIONS: A progression of degenerative changes in the cervical spine on MRI over the 20-year period was detected in nearly all subjects. There was no relationship between the progression of degeneration on MRI and the development of clinical symptoms, with the exception of an association found between foraminal stenosis and upper-limb pain. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

STUDY DESIGN: Retrospective review of surgically treated 481 adult patients with spinal disorders. OBJECTIVE: The aim of this study was to elucidate the effect of frailty and comorbidities on postoperative health-related quality of life (HRQoL) and complication rates. SUMMARY OF BACKGROUND DATA: Elective surgeries for spinal disorders not only improve clinical outcomes but also have high complication rates. METHODS: We retrospectively reviewed the results of consecutive elective spine surgeries for 156 adult spinal deformities (ASDs: 65 ± 9 years), 152 degenerative spondylolisthesis (DS: 64 ± 10 years), or 173 lumbar spinal canal stenosis (LSCS: 71 ± 9 years) with follow-up of at least 2 years. Modified Frailty Index (mFI) and Charlson Comorbidity Index (CCI) were determined from baseline demographics. We compared the prevalence and the influence of mFI and CCI on postoperative outcomes and complication rates. RESULTS: The mFI and CCI were significantly worse in ASD than in others (mFI: ASD 0.09 ± 0.12, DS 0.06 ± 0.06, LSCS 0.04 ± 0.05, P < 0.01. CCI: ASD 2.1 ± 1.6, DS 1.4 ± 0.7, LSCS 1.6 ± 0.9, P < 0.01). Postoperative HRQoL deteriorated as mFI worsened in ASD (nofrail: Oswestry Disability Index [ODI] 26 ± 11, Scoliosis Research Society Questionnaire [SRS] 3.7 ± 0.7; prefrail: ODI 32 ± 12, SRS 3.6 ± 0.6; frail: ODI 42 ± 15, SRS 3.2 ± 0.7). In DS and LSCS, however, SF-36 physical component score and mental component score improved regardless of mFI and CCI. The 2-year major complications rate increased with frailty (36%, 58%, and 81%) in ASD, but not in others. CONCLUSION: ASDs were more frail and had more comorbidities than the other populations. In ASD, postsurgical outcomes and complication rates deteriorated as frailty and CCI increased, whereas surgery produced favorable outcomes and acceptable complication rates in DS and LSCS regardless of frailty and CCI. Careful patient selection and treatment of comorbidities before surgery may decrease complications and improve outcomes for the surgical treatment of ASD. LEVEL OF EVIDENCE: 4.

Extramedullary hematopoiesis (EMH) occasionally occurs in patients exhibiting hematological disorders with decreased hematopoietic efficacy. EMH is rarely observed in the spinal epidural space and patients are usually asymptomatic. In particular, in the patients with polycythemia vera, spinal cord compression due to EMH is extremely rare. We report a case of polycythemia vera, in which operative therapy proved to be an effective treatment for myelopathy caused by spinal EMH.

BACKGROUND: Postoperative coronal imbalance is a significant problem after selective thoracic fusion for primary thoracic and compensatory lumbar curves in adolescent idiopathic scoliosis (AIS). However, longitudinal studies on postoperative behavior of coronal balance are lacking. This multicenter retrospective study was conducted to analyze factors related to onset and remodeling of postoperative coronal imbalance after posterior thoracic fusion for Lenke 1C and 2C AIS. METHODS: Twenty-one Lenke 1C or 2C AIS patients, who underwent posterior thoracic fusion ending at L3 or above, were included with a minimum 2-year follow-up. The mean patients' age was 15.1 years at the time of surgery. Radiographic measurements were performed on Cobb angles of the main thoracic (MT) and thoracolumbar/lumbar (TLL) curves and coronal balance. Factors related to the onset of immediately postoperative coronal decompensation (IPCD) and postoperative coronal balance remodeling (PCBR), defined as an improvement of coronal balance during postoperative follow-up, were investigated using comparative and correlation analyses. RESULTS: Mean Cobb angles for the MT and TLL curves were 57.3° and 42.3° preoperatively and were corrected to 22.8° and 22.5° at final follow-up, respectively. Mean preoperative coronal balance of -3.8 mm got worse to -21.2 mm postoperatively, and regained to -12.0 mm at final follow-up. Coronal decompensation was observed in two patients preoperatively, in ten patients immediately postoperatively, and in three patients at final follow-up. The preoperative coronal balance and lowest instrumented vertebra (LIV) selection relative to stable vertebra (SV) were significantly different between patients with IPCD and those without. PCBR had significantly negative correlation with immediately postoperative coronal balance. CONCLUSIONS: IPCD after posterior thoracic fusion for Lenke 1C and 2C AIS was frequent and associated with preoperative coronal balance and LIV selection. However, most patients with IPCD regained coronal balance through PCBR, which was significantly associated with immediately postoperative coronal balance. A fixation more distal to SV shifted the coronal balance further to the left postoperatively.