Decrease in pelvic incidence after adult spinal deformity surgery is a predictive factor for progression of hip joint osteoarthritis.

BACKGROUND: This study aimed to evaluate the association between spinopelvic alignment parameters and hip osteoarthritis progression after spinal alignment correction surgery for adult spinal deformity, focusing on the preoperative to postoperative change in spinopelvic alignment. METHODS: This retrospective study enrolled 100 adult spinal deformity patients (196 hip joints) who underwent spinal fusion surgery, after excluding four joints with previous total hip arthroplasty. Acetabular roof obliquity (ARO), center edge angle (CE) and Kellgren and Lawrence (KL) grade were measured in the hip joint. Spinopelvic alignment parameters were measured preoperatively and 1-month postoperatively and the changes (Δ) during this period were calculated. Patients were followed-up for ≥ 5 years and factors associated with KL grade progression at 5-years postoperatively were determined by logistic regression analysis. RESULTS: In the analysis with all cases, KL grade progressed in 23 joints. Logistic regression analysis revealed age (OR: 1.098, 95% CI: 1.007-1.198, p = 0.019), ARO (OR: 1.176, 95% CI: 1.01-1.37, p = 0.026), and Δ PI (OR: 0.791, 95% CI: 0.688-0.997, p < 0.001) as parameters significantly associated with KL grade progression. On the other hand, in the analysis limited to 185 cases with 1-month postoperative KL grade of 0, KL grade progressed in 13 joints. Logistic regression analysis revealed PI-LL (OR: 1.058, 95% CI: 1.001-1.117, p = 0.04), ΔPI (OR: 0.785, 95% CI: 0.649-0.951, p < 0.001), and ΔCobb (OR: 1.127, 95% CI: 1.012-1.253, p = 0.009) as parameters significantly associated with progression. CONCLUSIONS: Both the overall and limited analyzes of this study identified preoperative to postoperative change in PI as parameters affecting the hip osteoarthritis progression after spinal fusion surgery. Decrease in PI might represent preexisting sacroiliac joint laxity. Patients with this risk factor should be carefully followed for possible hip osteoarthritis progression.

Histology and chronological magnetic resonance images of congenital spinal deformity: An experimental study in mice model.

BACKGROUND: The natural history of the congenital spinal deformity and its clinical magnitude vary widely in human species. However, we previously reported that the spinal deformities of congenital scoliosis mice did not progress throughout our observational period according to soft X-ray and MRI data. In this study, congenital vertebral and intervertebral malformations in mice were assessed via magnetic resonance (MR) and histological images. METHODS: Congenital spinal anomalies were chronologically assessed via soft X-ray and 7 T MR imaging. MR images were compared to the histological images to validate the findings around the malformations. RESULTS: Soft X-ray images showed the gross alignment of the spine and the contour of the malformed vertebrae, with the growth plate and cortical bone visible as higher density lines, but could not be used to distinguish the existence of intervertebral structures. In contrast, MR images could be used to distinguish each structure, including the cortical bone, growth plate, cartilaginous end plate, and nucleus pulposus, by combining the signal changes on T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI). The intervertebral structure adjacent to the malformed vertebrae also exhibited various abnormalities, such as growth plate and cartilaginous end plate irregularities, nucleus pulposus defects, and bone marrow formation. In the chronological observation, the thickness and shape of the malformed structures on T1WI did not change. CONCLUSIONS: Spinal malformations in mice were chronologically observed via 7 T MRI and histology. MR images could be used to distinguish the histological structures of normal and malformed mouse spines. Malformed vertebrae were accompanied by adjacent intervertebral structures that corresponded to the fully segmented structures observed in human congenital scoliosis, but the intervertebral conditions varied. This study suggested the importance of MRI and histological examinations of human congenital scoliosis patients with patterns other than nonsegmenting patterns, which may be used to predict the prognosis of patients with spinal deformities associated with malformed vertebrae.

Trends in cervical laminoplasty and 30-day postoperative complications: 10-year results from a retrospective, multi-institutional study of 1095 patients.

PURPOSE: This study aimed to investigate the recent 10-year trends in cervical laminoplasty and 30-day postoperative complications. METHODS: This retrospective multi-institutional cohort study enrolled patients who underwent laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament. The primary outcome was the occurrence of all-cause 30-day complications. Trends were investigated and compared in the early (2008-2012) and late (2013-2017) periods. RESULTS: Among 1095 patients (mean age, 66 years; 762 [70%] male), 542 and 553 patients were treated in the early and late periods, respectively. In the late period, patients were older at surgery (65 years vs. 68 years), there were more males (66% vs. 73%), and open-door laminoplasty (50% vs. 69%) was the preferred procedure, while %CSM (77% vs. 78%) and the perioperative JOA scores were similar to the early period. During the study period, the rate of preservation of the posterior muscle-ligament complex attached to the C2/C7-spinous process (C2, 89% vs. 93%; C7, 62% vs. 85%) increased and the number of laminoplasty levels (3.7 vs. 3.1) decreased. While the 30-day complication rate remained stable (3.9% vs. 3.4%), C5 palsy tended to decrease (2.4% vs. 0.9%, P = 0.059); superficial SSI increased significantly (0% vs. 1.3%, P = 0.015), while the decreased incidence of deep SSI did not reach statistical significance (0.6% vs. 0.2%). CONCLUSIONS: From 2008 to 2017, there were trends toward increasing age at surgery and surgeons' preference for refined open-door laminoplasty. The 30-day complication rate remained stable, but the C5 palsy rate halved.

Anterior fusion surgery with overcorrection in the treatment of adolescent idiopathic scoliosis with Lenke 1 AR curve type: how to achieve overcorrection and its effect on postoperative spinal alignment.

BACKGROUND: The efficacy of anterior fusion with overcorrection in the instrumented vertebra for Lenke 1 AR type curves has been reported, but how to achieve overcorrection and how overcorrection affects spinal alignment are unclear. The purpose of this study was to identify the factors that cause overcorrection, and to investigate how overcorrection affects postoperative spinal alignment in the surgical treatment of Lenke 1 AR type curves. METHODS: Patients who had anterior surgery for a Lenke type 1 or 2 and lumbar modifier AR (L4 vertebral tilt to the right) type scoliosis and minimum 2-year follow-up were included. The radiographic data were measured at preoperative, postoperative 1 month, and final follow-up. The UIV-LIV Cobb angle was determined as the Cobb angle between the upper instrumented vertebra (UIV) and the lower instrumented vertebra (LIV), and a negative number for this angle was considered overcorrection. The screw angle was determined to be the sum of the angle formed by the screw axis and the lower and upper endplates in the LIV and UIV, respectively. The change (Δ) in the parameters from postoperative to final follow-up was calculated. The relationships between the UIV-LIV Cobb angle and other radiographic parameters were evaluated by linear regression analyses. RESULTS: Fourteen patients met the inclusion criteria. Their median age was 15.5 years, and the median follow-up period was 53.6 months. The median UIV-LIV Cobb angle was -1.4° at postoperative 1 month. The median screw angle was 4.7°, and overcorrection was achieved in 11 (79%) cases at postoperative 1 month. The screw angle (r2 = 0.42, p = 0.012) and Δ FDUV-CSVL (the deviation of the first distal uninstrumented vertebra from the central sacral vertical line, r2 = 0.53, p = 0.003) were significantly correlated with the UIV-LIV Cobb angle. CONCLUSIONS: Screw placement in the UIV and LIV not parallel to the endplate, but angled, was an effective method to facilitate overcorrection in the instrumented vertebrae. The results of the present study suggest that overcorrection could bring spontaneous improvement of coronal balance below the instrumented segment during the postoperative period.

Randomized trial of granulocyte colony-stimulating factor for spinal cord injury.

Attenuation of the secondary injury of spinal cord injury (SCI) can suppress the spread of spinal cord tissue damage, possibly resulting in spinal cord sparing that can improve functional prognoses. Granulocyte colony-stimulating factor (G-CSF) is a haematological cytokine commonly used to treat neutropenia. Previous reports have shown that G-CSF promotes functional recovery in rodent models of SCI. Based on preclinical results, we conducted early phase clinical trials, showing safety/feasibility and suggestive efficacy. These lines of evidence demonstrate that G-CSF might have therapeutic benefits for acute SCI in humans. To confirm this efficacy and to obtain strong evidence for pharmaceutical approval of G-CSF therapy for SCI, we conducted a phase 3 clinical trial designed as a prospective, randomized, double-blinded and placebo-controlled comparative trial. The current trial included cervical SCI [severity of American Spinal Injury Association (ASIA) Impairment Scale (AIS) B or C] within 48 h after injury. Patients are randomly assigned to G-CSF and placebo groups. The G-CSF group was administered 400 µg/m2/day × 5 days of G-CSF in normal saline via intravenous infusion for five consecutive days. The placebo group was similarly administered a placebo. Allocation was concealed between blinded evaluators of efficacy/safety and those for laboratory data, as G-CSF markedly increases white blood cell counts that can reveal patient treatment. Efficacy and safety were evaluated by blinded observer. Our primary end point was changes in ASIA motor scores from baseline to 3 months after drug administration. Each group includes 44 patients (88 total patients). Our protocol was approved by the Pharmaceuticals and Medical Device Agency in Japan and this trial is funded by the Center for Clinical Trials, Japan Medical Association. There was no significant difference in the primary end point between the G-CSF and the placebo control groups. In contrast, one of the secondary end points showed that the ASIA motor score 6 months (P = 0.062) and 1 year (P = 0.073) after drug administration tend to be higher in the G-CSF group compared with the placebo control group. Moreover, in patients aged over 65 years old, motor recovery 6 months after drug administration showed a strong trend towards a better recovery in the G-CSF treated group (P = 0.056) compared with the control group. The present trial failed to show a significant effect of G-CSF in primary end point although the subanalyses of the present trial suggested potential G-CSF benefits for specific population.

Thoracic kyphosis in light of lumbosacral alignment in thoracic adolescent idiopathic scoliosis: recognition of thoracic hypokyphosis and therapeutic implications.

BACKGROUND: The uniqueness of spinal sagittal alignment in thoracic adolescent idiopathic scoliosis (AIS), for example, the drastically smaller thoracic kyphosis seen in some patients, has been recognized but not yet fully understood. The purpose of this study was to clarify the characteristics of sagittal alignment of thoracic AIS and to determine the contributing factors. METHODS: Whole spine radiographs of 83 thoracic AIS patients (73 females) were analyzed. The measured radiographic parameters were the Cobb angle of thoracic scoliosis, thoracic kyphosis (TK), lumbar lordosis (LL), C7 sagittal vertical axis (C7 SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Additionally, max-LL, which was defined as the maximum lordosis angle from the S1 endplate, the inflection point between thoracic kyphosis and lumbar lordosis, and the SVA of the inflection point (IP SVA) were measured. The factors significantly related to a decrease in TK were assessed by stepwise logistic regression analysis. In addition, cluster analysis was performed to classify the global sagittal alignment. RESULTS: The significant factors for a decrease in TK were an increase in SS (p = 0.0003, [OR]: 1.16) and a decrease in max-LL (p = 0.0005, [OR]: 0.89). According to the cluster analysis, the global sagittal alignment was categorized into the following three types: Type 1 (low SS, low max-LL, n = 28); Type 2 (high SS, low max-LL, n = 22); and Type 3 (high SS, high max-LL, n = 33). CONCLUSIONS: In thoracic AIS, a decreased TK corresponded to an increased SS or a decreased max-LL. The sagittal alignment of thoracic AIS patients could be classified into three types based on SS and max-LL. One of these three types includes the unique sagittal profile of very small TK.

Multiple concave rib head resection improved correction rate of posterior spine fusion in treatment of adolescent idiopathic scoliosis.

BACKGROUND: Hybrid constructs have been widely used to surgically correct thoracic adolescent idiopathic scoliosis (AIS). To enhance the correction obtained with hybrid constructs, we perform concave rib head resection and convex costovertebral release as posterior release procedures. The objective of the study was to evaluate coronal and sagittal curve correction in patients with adolescent idiopathic scoliosis (AIS) treated with hybrid constructs combined with concave rib head resection and convex transverse process resection as posterior release procedures. METHODS: The records of 24 patients with Lenke type 1 or 2 AIS treated with hybrid constructs combined with posterior release procedures were retrospectively reviewed. The mean age at surgery was 14.3 years. The mean follow-up period was 33.0 months (range, 24-60 months). Radiographs were evaluated before surgery, immediately postoperatively, and at latest follow-up. RESULTS: The average preoperative Cobb angle of the main thoracic (MT) curve was 58.1 ± 12.6° (range, 45-88°). The MT curve was corrected to 12.8 ± 9.0° (range, 0-38°) immediately after surgery. At the latest follow-up, the average Cobb angle was 13.6 ± 9.9° (range, 0-44°; correction, 77.5 ± 14.0%). The average loss of coronal correction was 0.8°. The average preoperative flexibility of the MT curve was 54.6 ± 17.4%. The average Cincinnati correction index was 1.53 ± 0.48 at the latest follow-up. The average preoperative thoracic kyphosis (TK) was 13.7 ± 12.0° (range, -12-34°). Immediately after surgery, TK was corrected to 18.6 ± 5.9° (range, 10-29°). At the latest follow-up, TK measured 18.1 ± 6.5° (range, 6-32°). CONCLUSIONS: Hybrid instrumentation combined with concave rib head resection and convex transverse process resection as posterior release procedures achieved satisfactory coronal and sagittal curve correction with little loss of correction at 2-year follow-up.

Dynamic global sagittal alignment evaluated by three-dimensional gait analysis in patients with degenerative lumbar kyphoscoliosis.

PURPOSE: Sagittal vertical axis (SVA) is the most commonly used parameter for evaluating global sagittal alignment (GSA) in a static condition. However, its dynamic statuses remain unclear. The aim of this study was to evaluate dynamic GSA of degenerative lumbar kyphoscoliosis (DLKS) using three-dimensional motion analysis system (3D-MAS). METHODS: Twenty-six patients with DLKS underwent gait analysis using 3D-MAS. Static (S-) and dynamic (D-) trunk angle (TA) (the angle between the vertical axis and the line connecting C7 and S1 spinous processes) and S-sagittal trunk shift (STS) and D-STS (the distance between the two vertical lines running through C7 and S1 spinous process) were recorded during treadmill walking. Pelvic angle (PA) (the angle between the horizontal axis and the line connecting the posterior and anterior superior iliac spine) were also recorded. S-PA and D-PA represent retroversion or anteversion of the pelvis, which can be substituted for pelvic tilt. As to dynamic parameters, those at the initial five steps (Di) and the final five steps (Df) of treadmill walking were also recorded. RESULTS: The median S-TA, S-STS, and S-PA were 16.0°, 11.9 cm, and -5.5° (retroversion). The median D parameters were Di-TA/Df-TA 21.8°/26.9°; Di-STS/Df-STS 14.1/21.1 cm; and Di-PA/Df-PA 15.7°/22.8° (anteversion). All D parameters were significantly greater than S parameters (P < 0.01) and all Df parameters were also significantly worse than Di parameters (P < 0.001). Thus, compensated GSA by pelvic retroversion in static condition was lost due to anteversion change of the pelvis immediately after start of walking and worsened over time. CONCLUSION: Dynamic GSA assessment using 3D-MAS can avoid underestimation of GSA loss that is detected by static standing full-length radiography.

Optimum pelvic incidence minus lumbar lordosis value can be determined by individual pelvic incidence.

PURPOSE: Adult spinal deformity (ASD) classification showing that ideal pelvic incidence minus lumbar lordosis (PI-LL) value is within 10° has been received widely. But no study has focused on the optimum level of PI-LL value that reflects wide variety in PI among patients. This study was conducted to determine the optimum PI-LL value specific to an individual's PI in postoperative ASD patients. METHODS: 48 postoperative ASD patients were recruited. Spino-pelvic parameters and Oswestry Disability Index (ODI) were measured at the final follow-up. Factors associated with good clinical results were determined by stepwise multiple regression model using the ODI. The patients with ODI under the 75th percentile cutoff were designated into the "good" health related quality of life (HRQOL) group. In this group, the relationship between the PI-LL and PI was assessed by regression analysis. RESULTS: Multiple regression analysis revealed PI-LL as significant parameters associated with ODI. Thirty-six patients with an ODI <22 points (75th percentile cutoff) were categorized into a good HRQOL group, and linear regression models demonstrated the following equation: PI-LL = 0.41PI-11.12 (r = 0.45, P = 0.0059). CONCLUSIONS: On the basis of this equation, in the patients with a PI = 50°, the PI-LL is 9°. Whereas in those with a PI = 30°, the optimum PI-LL is calculated to be as low as 1°. In those with a PI = 80°, PI-LL is estimated at 22°. Consequently, an optimum PI-LL is inconsistent in that it depends on the individual PI.

Prospective Registration Study for Establishing Minimal Clinically Important Differences in Patients Undergoing Surgery for Spinal Metastases.

STUDY DESIGN: Multicenter, prospective registry study. OBJECTIVE: To clarify minimal clinically important differences (MCIDs) for surgical interventions for spinal metastases, thereby enhancing patient care by integrating quality of life (QoL) assessments with clinical outcomes. SUMMARY OF BACKGROUND DATA: Despite its proven usefulness in degenerative spinal diseases and deformities, the MCID remains unexplored regarding surgery for spinal metastases. METHODS: This study included 171 (out of 413) patients from the multicenter "Prospective Registration Study on Surgery for Metastatic Spinal Tumors" by the Japan Association of Spine Surgeons. These were evaluated preoperatively and at 6 months postoperatively using the Face scale, EuroQol-5 Dimensions-5 Levels (EQ-5D-5L), including the visual analog scale (VAS), and performance status. The MCIDs were calculated using an anchor-based method, classifying participants into the improved, unchanged, and deteriorated groups based on the Face scale scores. Focusing on the improved and unchanged groups, the change in the EQ-5D-5L values from before to after treatment was analyzed, and the cutoff value with the highest sensitivity and specificity was determined as the MCID through receiver operating characteristic curve analysis. The validity of the MCIDs was evaluated using a distribution-based calculation method for patient-reported outcomes. RESULTS: The improved, unchanged, and deteriorated groups comprised 121, 28, and 22 participants, respectively. The anchor-based MCIDs for the EQ-5D-5L index, EQ-VAS, and domains of mobility, self-care, usual activities, pain/discomfort, and anxiety/depression were 0.21, 15.50, 1.50, 0.50, 0.50, 0.50, and 0.50, respectively; the corresponding distribution-based MCIDs were 0.17, 15,99, 0.77, 0.80, 0.78, 0.60, and 0.70, respectively. CONCLUSION: We identified MCIDs for surgical treatment of spinal metastases, providing benchmarks for future clinical research. By retrospectively examining whether the MCIDs are achieved, factors favoring their achievement and risks affecting them can be explored. This could aid in decisions on surgical candidacy and patient counseling.

Comparison of Surgical Outcomes of Anterior and Posterior Fusion Surgeries for K-line (-) Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Multicenter Study.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: The objective of this study is to compare the surgical outcomes of anterior and posterior fusion surgeries in patients with K-line (-) cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: Although laminoplasty is effective for patients with K-line (+) OPLL, fusion surgery is recommended for those with K-line (-) OPLL. However, whether the anterior or posterior approach is preferable for this pathology has not been effectively determined. MATERIALS AND METHODS: A total of 478 patients with myelopathy due to cervical OPLL from 28 institutions were prospectively registered from 2014 to 2017 and followed up for two years. Of the 478 patients, 45 and 46 with K-line (-) underwent anterior and posterior fusion surgeries, respectively. After adjusting for confounders in baseline characteristics using a propensity score-matched analysis, 54 patients in both the anterior and posterior groups (27 patients each) were evaluated. Clinical outcomes were assessed using the cervical Japanese Orthopaedic Association and the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire. RESULTS: Both approaches showed comparable neurological and functional recovery. The cervical range of motion was significantly restricted in the posterior group because of the large number of fused vertebrae compared with the anterior group. The incidence of surgical complications was comparable between the cohorts, but the posterior group demonstrated a higher frequency of segmental motor paralysis, whereas the anterior group more frequently reported postoperative dysphagia. CONCLUSIONS: Clinical improvement was comparable between anterior and posterior fusion surgeries for patients with K-line (-) OPLL. The ideal surgical approach should be informed based on the balance between the surgeon's technical preference and the risk of complications.

Preoperative Symptom Duration Influences Neurological Recovery and Patient-Reported Outcome Measures After Surgical Treatment of Cervical Ossification of the Posterior Longitudinal Ligament.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: To investigate the effect of preoperative symptom duration on neurological recovery for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: The optimal timing to perform surgery in the setting of cervical OPLL remains unknown. It is important to know the influence of symptom duration on postoperative outcomes to facilitate discussions regarding the timing of surgery. PATIENTS AND METHODS: The study included 395 patients (291 men and 104 women; mean age, 63.7 ± 11.4 yr): 204 were treated with laminoplasty, 90 with posterior decompression and fusion, 85 with anterior decompression and fusion, and 16 with other procedures. The Japanese Orthopedic Association (JOA) score and patient-reported outcomes of the JOA Cervical Myelopathy Evaluation Questionnaire were used to assess clinical outcomes preoperatively and 2 years after surgery. Logistic regression analysis was used to identify factors associated with the achievement of minimum clinically important difference (MCID) after surgery. RESULTS: The recovery rate was significantly lower in the group with symptom duration of ≥5 years compared with the groups with durations of <0.5 years, 0.5 to 1 year, and 1 to 2 years. Improvement of JOA Cervical Myelopathy Evaluation Questionnaire in the upper extremity function score ( P < 0.001), lower extremity function ( P = 0.039), quality of life ( P = 0.053), and bladder function ( P = 0.034) were all decreased when the symptom duration exceeded 2 years. Duration of symptoms ( P = 0.001), age ( P < 0.001), and body mass index ( P < 0.001) were significantly associated with the achievement of MCID. The cutoff value we established for symptom duration was 23 months (area under the curve, 0.616; sensitivity, 67.4%; specificity, 53.5%). CONCLUSIONS: Symptom duration had a significant impact on neurological recovery and patient-reported outcome measures in this series of patients undergoing surgery for cervical OPLL. Patients with symptom duration exceeding 23 months may be at greater risk of failing to achieve MCID after surgery. LEVEL OF EVIDENCE: 3.

Factors Associated With Loss of Cervical Lordosis After Laminoplasty for Patients With Cervical Ossification of the Posterior Longitudinal Ligament: Data From a Prospective Multicenter Study.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: The objective of this study was to investigate the incidence of loss of cervical lordosis after laminoplasty for cervical ossification of the posterior longitudinal ligament (OPLL). We also sought to determine associated risk factors and the relationship with patient-reported outcomes. SUMMARY OF BACKGROUND DATA: Loss of cervical lordosis is a sequelae often observed after laminoplasty, which may adversely impact surgical outcomes. Cervical kyphosis, especially in OPLL, is associated with reoperation, but risk factors and relationship to postoperative outcomes remain understudied at this time. MATERIALS AND METHODS: This study was conducted by the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. We included 165 patients who underwent laminoplasty and completed Japanese Orthopaedic Association (JOA) score or Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaires (JOACMEQ), as well as Visual Analog Scales (VAS) for pain, with imaging. The participants were divided into two groups: those with loss of cervical lordosis of >10° or 20° after surgery and those without loss of cervical lordosis. A paired t test was applied to evaluate the association between changes in cervical spinal angles, range of motion, and cervical JOA and VAS scores before and at 2 years postoperatively. Mann-Whitney U test was used for JOACMEQ. RESULTS: Postoperative loss of cervical lordosis >10° and >20° was observed in 32 (19.4%) and 7 (4.2%), respectively. JOA, JOACMEQ, and VAS scores were not significantly different between those with, and without, loss of cervical lordosis. Preoperative small extension range of motion (eROM) was significantly associated with postoperative loss of cervical lordosis, and the cutoff values of eROM were 7.4° [area under the curve (AUC): 0.76] and 8.2° (AUC: 0.92) for loss of cervical lordosis >10° and >20°, respectively. A large occupation ratio of OPLL was also associated with loss of cervical lordosis, with a cutoff value of 39.9% (AUC: 0.94). Laminoplasty resulted in functional improvement in most patient-reported outcomes; however, neck pain and bladder function tended to become worse postoperatively in cases with postoperative loss of cervical lordosis >20°. CONCLUSIONS: JOA, JOACMEQ, and VAS scores were not significantly different between those with, and without, loss of cervical lordosis. Preoperative small eROM and large OPLL may represent factors associated with loss of cervical lordosis after laminoplasty in patients with OPLL.

Anterior instrumentation surgery for the treatment of Lenke type 1AR curve patterns.

OBJECTIVE: Previous studies have demonstrated that Lenke lumbar modifier A contains 2 distinct types (AR and AL), and the AR curve pattern is likely to develop adding-on (i.e., a progressive increase in the number of vertebrae included within the primary curve distally after posterior surgery). However, the results of anterior surgery are unknown. The purpose of this study was to present the surgical results in a cohort of patients undergoing scoliosis treatment for type 1AR curves and to compare anterior and posterior surgeries to consider the ideal indications and advantages of anterior surgery for type 1AR curves. METHODS: Patients with a Lenke type 1 or 2 and lumbar modifier AR (L4 vertebral tilt to the right) and a minimum 2-year postoperative follow-up were included. The incidence of adding-on and radiographic data were compared between the anterior and posterior surgery groups. The numbers of levels between the end, stable, neutral, and last touching vertebra to the lower instrumented vertebra (LIV) were also evaluated. RESULTS: Forty-four patients with a mean follow-up of 57 months were included. There were 14 patients in the anterior group and 30 patients in the posterior group. The main thoracic Cobb angle was not significantly different between the groups preoperatively and at final follow-up. At final follow-up, the anterior group had significantly less tilting of the LIV than the posterior group (-0.8° ± 4.5° vs 3° ± 4°). Distal adding-on was observed in no patient in the anterior group and in 6 patients in the posterior group at final follow-up (p = 0.025). In the anterior group, no LIV was set below the end vertebra, and all LIVs were set above last touching vertebra. The LIV was significantly more proximal in the anterior group than in the posterior surgery patients without adding-on for all reference vertebrae (p < 0.001). CONCLUSIONS: This is the first study to investigate the surgical results of anterior surgery for Lenke type 1AR curve patterns, and it showed that anterior surgery for the curves could minimize the distal extent of the instrumented fusion without adding-on. This would leave more mobile disc space below the fusion.

Can we use shorter constructs while maintaining satisfactory sagittal plane alignment for adult spinal deformity?

OBJECTIVE: Issues with spinopelvic fixation for adult spinal deformity (ASD) include loss of the physiological mobility of the entire lumbar spine, perioperative complications, and medical costs. Little is known about the factors associated with successful short fusion for ASD. The authors evaluated radiographic and clinical outcomes after shorter fusion for different subtypes of ASD at 2 years postoperatively and examined factors associated with successful short fusion. METHODS: This was a single-center study of 37 patients who underwent short fusion and a minimum 2 years of follow-up for ASD in which lumbar kyphosis was the main deformity. The exclusion criteria were 1) age < 40 years, 2) previous lumbar vertebral fracture, 3) severe osteoporosis, 4) T10-L2 kyphosis > 20°, 5) scoliotic deformity with an upper end vertebra (UEV) above T12, and 6) concomitant Parkinson's disease or neurological disease. The surgical procedures, radiographic course, and Oswestry Disability Index (ODI) were assessed, and correlations between radiographic parameters and postoperative ODI at 2 years were analyzed. RESULTS: A mean of 3.5 levels were fused. The mean radiographic parameters preoperatively, at 2 weeks, and at 2 years, respectively, were as follows: coronal Cobb angle: 22.9°, 11.5°, and 12.6°; lumbar lordosis (LL): 12.9°, 35.8°, and 32.2°; pelvic incidence (PI) minus LL: 35.5°, 14.7°, and 19.2°; pelvic tilt: 29.4°, 23.1°, and 25.0°; and sagittal vertical axis 85.3, 36.7, and 59.2 mm. Abnormal proximal junctional kyphosis occurred in 8 cases. Revision surgery was performed to extend the length of fusion from a lower thoracic vertebra to the pelvis in 2 cases. The mean ODI scores preoperatively and at 2 years were 50.7% and 24.1%, respectively. Patient age, number of fused intervertebral segments, and radiographic parameters were analyzed by the stepwise method to identify factors contributing to the ODI score at 2 years, preoperative PI, and sagittal vertical axis at 2 years. On receiver operating characteristic curve analysis of the minimal clinically important difference of ODI (15%) and preoperative PI, the cutoff value of the preoperative PI was 47° (area under the curve 0.75). CONCLUSIONS: In terms of subtypes of ASD in which lumbar kyphosis is the main deformity, if the PI is < 47°, then the use of short fusion preserving mobile intervertebral segments can produce adequate LL for the PI, improving both postoperative global spinal alignment and quality of life.

Can we stop the long fusion at L5 for selected adult spinal deformity patients with less severe disability and less complex deformity?

OBJECTIVES: It is controversial whether to stop the fusion at L5 or S1 in adult spinal deformity (ASD) surgery. Our hypothesis is that we can stop long fusion at L5 for selected patients with less severe disability and less complex deformity. Aim was to compare minimum 5-year outcomes between ASD patients with fusion to L5 versus S1. PATIENTS AND METHODS: Consecutive 40 patients (≥50 years of age) with ASD underwent spinal fusion from lower thoracic spine to L5 or S1 between 2008 and 2011. 33 patients (82.5 %) had a minimum 5-year follow-up. Lower instrumented vertebra (LIV) was L5 in 12 patients (L5 group) and S1 in 21 (S1 group). Clinical and radiographical parameters were compared between L5 and S1 group. RESULTS: There were statistically significant differences between two groups (L5 vs S1) in %male (50 % vs 14 %), %type-N of SRS-Schwab classification (83 % vs 38 %), preop ODI (40.5 vs 56), correction loss of LL (11˚ vs 3˚), final TK (32˚ vs 50˚), correction loss of TK (-1˚ vs 17˚), final improvement of PT (3˚ vs 10˚), final improvement of PI-LL (26˚ vs 39˚), PJK (8% vs 48 %), and revision surgery rate (50 % vs 14 %). Causes of revision surgery in L5 group were distal junctional failure in 5 patients and foraminal stenosis at L5-S1 in 1. All of them underwent additional spinal fusion to the sacrum. Whereas, causes of revision surgery in S1 group were rod fracture in 2 patients and proximal junctional failure in 1. CONCLUSION: Although fusion to L5 was conducted for selected ASD patients with less severe disability (better ODI) and less complex deformity (type N), 50 % of the patients required additional fusion to the pelvis. Decision making to stop the long fusion at L5 for ASD patients ≥50 years of age should be made with careful considerations.

Growing rod technique with prior foundation surgery and sublaminar taping for early-onset scoliosis.

OBJECTIVE: The aim of this study was to show the surgical results of growing rod (GR) surgery with prior foundation surgery (PFS) and sublaminar taping at an apex vertebra. METHODS: Twenty-two early-onset scoliosis (EOS) patients underwent dual GR surgery with PFS and sublaminar taping. PFS was performed prior to rod placement, including exposure of distal and proximal anchor areas and anchor instrumentation filled with a local bone graft. After a period of 3-5 months for the anchors to become solid, dual rods were placed for distraction. The apex vertebra was exposed and fastened to the concave side of the rods using sublaminar tape. Preoperative, post-GR placement, and final follow-up radiographic parameters were measured. Complications during the treatment period were evaluated using the patients' clinical records. RESULTS: The median age at the initial surgery was 55.5 months (range 28-99 months), and the median follow-up duration was 69.5 months (range 25-98 months). The median scoliotic curves were 81.5° (range 39°-126°) preoperatively, 30.5° (range 11°-71°) after GR placement, and 33.5° (range 12°-87°) at the final follow-up. The median thoracic kyphotic curves were 45.5° (range 7°-136°) preoperatively, 32.5° (range 15°-99°) after GR placement, and 42° (range 11°-93°) at the final follow-up. The median T1-S1 lengths were 240.5 mm (range 188-305 mm) preoperatively, 286.5 mm (range 232-340 mm) after GR placement, and 337.5 mm (range 206-423 mm) at the final follow-up. Complications occurred in 6 patients (27%). Three patients had implant-related complications, 2 patients had alignment-related complications, and 1 patient had a wound-related complication. CONCLUSIONS: A dual GR technique with PFS and sublaminar taping showed effective correction of scoliotic curves and a lower complication rate than previous reports when a conventional dual GR technique was used.

Pedicle screws with a thin hydroxyapatite coating for improving fixation at the bone-implant interface in the osteoporotic spine: experimental study in a porcine model.

OBJECTIVE Instrumentation failure caused by the loosening of pedicle screws (PSs) in patients with osteoporosis is a serious problem after spinal surgery. The addition of a thin hydroxyapatite (HA) surface coating applied by using a sputtering process was reported recently to be a promising method for providing bone conduction around an implant without a significant risk of coating-layer breakage. In this study, the authors evaluated the biomechanical and histological features of the bone-implant interface (BII) of PSs with a thin HA coating in an in vivo porcine osteoporotic spine model. METHODS Three types of PSs (untreated/standard [STPS], sandblasted [BLPS], and HA-coated [HAPS] PSs) were implanted into the thoracic and lumbar spine (T9-L6) of 8 mature Clawn miniature pigs (6 ovariectomized [osteoporosis group] and 2 sham-operated [control group] pigs). The spines were harvested from the osteoporosis group at 0, 2, 4, 8, 12, or 24 weeks after PS placement and from the control group at 0 or 24 weeks. Their bone mineral density (BMD) was measured by peripheral quantitative CT. Histological evaluation of the BIIs was conducted by performing bone volume/tissue volume and bone surface/implant surface measurements. The strength of the BII was evaluated with extraction torque testing. RESULTS The BMD decreased significantly in the osteoporosis group (p < 0.01). HAPSs exhibited the greatest mean extraction peak torque at 8 weeks, and HAPSs and BLPSs exhibited significantly greater mean torque than the STPSs at 12 weeks (p < 0.05). The bone surface/implant surface ratio was significantly higher for HAPSs than for STPSs after 2 weeks (p < 0.05), and bonding between bone and the implant surface was maintained until 24 weeks with no detachment of the coating layer. In contrast, the bone volume/tissue volume ratio was significantly higher for HAPSs than for BLPSs or STPSs only at 4 weeks. CONCLUSIONS Using PSs with a thin HA coating applied using a sputtering process strengthens bonding at the BII, which might improve early implant fixation after spinal surgery for osteoporosis. However, the absence of increased bone mass around the screw remains a concern; prescribing osteoporosis treatment to improve bone quality might be necessary to prevent fractures around the screws.

Postoperative Status of Global Sagittal Alignment With Compensation in Adult Spinal Deformity.

STUDY DESIGN: A retrospective study of consecutive patients undergoing surgery for adult spinal deformity (ASD). OBJECTIVE: The aim of this study was to classify postoperative ASD patients by sagittal compensation and characterize the features of each group. SUMMARY OF BACKGROUND DATA: Sagittal compensatory mechanisms to keep the erect position would function in not only nonoperative ASD patients but also in postoperative patients. However, details of sagittal compensatory mechanisms after surgery have been unclear, because the majority of previous studies examined the compensatory mechanisms in nonoperative patients. METHODS: A total of 73 postoperative ASD patients were recruited. Spinopelvic parameters and Oswestry Disability Index (ODI) were measured before surgery, at 1-month and 2-year follow-up. The changes in parameters (Δ) between postoperative 1-month and 2-year were also evaluated. Cluster analysis based on pelvic tilt (PT) and sagittal vertical axis (SVA) at 2-year follow-up was performed, and then the parameters were compared among clusters. RESULTS: Cluster analysis identified three clusters: the physiological group (n = 38, PT = 19.6°, SVA = 17.2 mm), the compensated group (n = 23, PT = 34.3°, SVA = 45.6 mm), and the decompensated group (n = 12, PT = 36.6°, SVA = 118.8 mm). Comparisons of the parameters among the groups showed that the physiological group had smaller pelvic incidence minus lumbar lordosis (PI-LL) and better ODI. The compensated group had significantly larger Δ thoracic kyphosis (TK), Δ proximal junctional angle (PJA), and ΔPT than the physiological group. The decompensated group had significantly higher PI and higher age. CONCLUSION: Three groups were defined in terms of postoperative compensatory mechanisms. Patients in the physiological group had little postoperative alignment change and good ODI value. The compensated group had pelvic retroversion to keep SVA in the physiological range, but the compensation in the thoracic spine was unlikely to work. High PI and advanced age were characteristics of the decompensated group. LEVEL OF EVIDENCE: 4.

Study protocol for the G-SPIRIT trial: a randomised, placebo-controlled, double-blinded phase III trial of granulocyte colony-stimulating factor-mediated neuroprotection for acute spinal cord injury.

INTRODUCTION: Granulocyte colony-stimulating factor (G-CSF) is generally used for neutropaenia. Previous experimental studies revealed that G-CSF promoted neurological recovery after spinal cord injury (SCI). Next, we moved to early phase of clinical trials. In a phase I/IIa trial, no adverse events were observed. Next, we conducted a non-randomised, non-blinded, comparative trial, which suggested the efficacy of G-CSF for promoting neurological recovery. Based on those results, we are now performing a phase III trial. METHODS AND ANALYSIS: The objective of this study is to evaluate the efficacy of G-CSF for acute SCI. The study design is a prospective, multicentre, randomised, double-blinded, placebo-controlled comparative study. The current trial includes cervical SCI (severity of American Spinal Injury Association (ASIA) Impairment Scale B/C) within 48 hours after injury. Patients are randomly assigned to G-CSF and placebo groups. The G-CSF group is administered 400 µg/m2/day×5 days of G-CSF in normal saline via intravenous infusion for 5 consecutive days. The placebo group is similarly administered a placebo. Our primary endpoint is changes in ASIA motor scores from baseline to 3 months. Each group includes 44 patients (88 total patients). ETHICS AND DISSEMINATION: The study will be conducted according to the principles of the World Medical Association Declaration of Helsinki and in accordance with the Japanese Medical Research Involving Human Subjects Act and other guidelines, regulations and Acts. Results of the clinical study will be submitted to the head of the respective clinical study site as a report after conclusion of the clinical study by the sponsor-investigator. Even if the results are not favourable despite conducting the clinical study properly, the data will be published as a paper. TRIAL REGISTRATION NUMBER: UMIN000018752.