Multiple-rod constructs and use of bone morphogenetic protein-2 in relation to lower rod fracture rates in 141 patients with adult spinal deformity who underwent lumbar pedicle subtraction osteotomy.

OBJECTIVE: The purpose of this study was to compare rod fracture (RF) rates among three types of rod constructs (RCs) following lumbar pedicle subtraction osteotomy (PSO) for adult spinal deformity (ASD). METHODS: A retrospective review of consecutive patients with adult spinal deformity who were treated with lumbar PSO between 2007 and 2017 was performed. The minimum follow-up was 2 years. Three RCs were compared: standard (2 main rods), satellite (2 main rods with satellite rod), and nested (2 main rods and 2 short rods spanning osteotomy). Outcomes examined included RF rate, time to RF, pseudarthrosis, and reoperation. Multivariate analysis was used. RESULTS: A total of 141 patients were included 55 with standard, 23 with satellite, and 63 with nested RCs. The mean age was 65.2 years and 34.8% of patients were male. Radiographic preoperative and postoperative results were as follows: sagittal vertical axis (11.0 vs 3.9 cm), lumbar lordosis (28.5° vs 57.1°), pelvic tilt (30.6° vs 21.0°), pelvic incidence (61.5° vs 60.0°), distance between central sacral vertical line and C7 plumb line (2.2 vs 1.5 cm), and scoliosis (18.9° vs 11.3°). The average time to RF was 12.4 months. Overall RF, bilateral RF, pseudarthrosis, and reoperation rates were 22.7%, 5.0%, 20.6%, and 17.7%, respectively. Standard RCs had a significantly higher RF (36.4% vs 13.0% vs 14.3%, p = 0.008), bilateral RF (35.0% vs 0.0% vs 0.0%, p = 0.021), pseudarthrosis (34.5% vs 8.7% vs 12.7%, p = 0.004), and reoperation (30.9% vs 4.3% vs 11.1%, p = 0.004) rates. Satellite RCs (OR 0.21, p = 0.015), nested RCs (OR 0.24, p = 0.003), and bone morphogenetic protein-2 (OR 0.28, p = 0.005) were independently associated with lower odds of RF. CONCLUSIONS: Use of multiple rods in the satellite RC and nested RC groups was associated with lower rates of RF, pseudarthrosis, and reoperations following lumbar PSO. Bone morphogenetic protein-2 was associated with a reduction in RF rate as well.

miR-384-5p promotes spinal cord injury recovery in rats through suppressing of autophagy and endoplasmic reticulum stress.

BACKGROUND: Spinal cord injury (SCI) is one of the most serious neurological disorders and is characterized by high morbidity and disability. Unfortunately, there is a lack of effective treatment. Recently, the micro RNA, miR-384-5p, was reported to play a significant role in cell survival in response to different insults. METHODS: In vitro model of traumatic neuronal injury was induced by application of a sharp sterile blade to generate cuts in PC12 cells, and in vivo SCI was produced by applying vascular clips (force of 15 g) to the dura via T9-T10 laminectomy, and then, the role of miR-384-5p in the development of SCI was investigated. RESULTS: Dual-luciferase reporter assays confirmed that miR-384-5p regulates the gene expression of Beclin-1, an important promoter of autophagy. Quantitative polymerase chain reaction and western blot analyses revealed that treatment with miR-384-5p decreased mRNA and protein expression of Beclin-1 in the mechanically injured PC12 cells. In rats with spinal cord compression injuries, miR-384-5p expression was significantly decreased. Treatment with miR-384-5p increased spinal cord neuron survival and promoted locomotor function recovery in rats. Further study revealed that miR-384-5p administration decreased immunofluorescent labeling of Beclin-1 in spinal cord tissues and reduced autophagosome formation in neurons, as shown by transmission electron microscopy. These results indicated that miR-384-5p promotes recovery of rats with SCI by suppressing autophagy via direct targeting of Beclin-1. Moreover, miR-384-5p also inhibited the activation of endoplasmic reticulum (ER) stress by decreasing GRP78 expression in both in vitro and in vivo models. CONCLUSIONS: This study for the first time demonstrates that the protective role of miR-384-5p in the process of SCI is associated with simultaneous suppression of autophagy and ER stress and miR-384-5p could be a promising candidate for SCI therapeutics.

Comparison of Extending Fusion to Thoracic Curve Versus Thoracolumbar/Lumbar Fusion in Posterior Fusion of Patients with Lenke 5C: Variation in Upper End Vertebrae Tilt Affected Coronal Balance.

BACKGROUND: Extended fusion can be performed in patients with Lenke 5C adolescent idiopathic scoliosis (AIS) with a large and relatively rigid thoracic curve. Progression of the thoracic curve is related to coronal imbalance. We aimed to determine the correlation between the upper instrumented vertebra choice and coronal balance in patients with Lenke 5C AIS. METHODS: A total of 61 patients with Lenke 5C AIS underwent posterior fusion from 2009 to 2015 in a single institution with ≥2 years of follow-up data available. The extended fusion group (n = 32) and thoracolumbar/lumbar (TL/L) fusion group (n = 29) were compared for the correction rates for the main TL/L and thoracic curves, coronal balance, upper end vertebra (UEV) tilt, and Scoliosis Research Society-22 questionnaire score. RESULTS: Both groups had excellent correction of the main TL/L curve, and the extended fusion group had a significantly greater correction rate of the thoracic curve than the TL/L fusion group (70.2% vs. 57.3%). The incidence of coronal imbalance was similar in both groups. The spontaneous change in UEV tilt was associated with the change in coronal balance from the first to the final follow-up examination. In the TL/L fusion group, the increase in UEV tilt from the first to final follow-up visit resulted in improved coronal balance at the final follow-up examination. Both groups had similar Scoliosis Research Society-22 questionnaire scores at 2 years postoperatively. CONCLUSIONS: In patients with Lenke 5C AIS, thoracic curve fusion results in better correction of the thoracic curve but no improvement in coronal balance. With TL/L fusion, a postoperative UEV tilt >5° leads to better coronal balance.

The Efficacy of Hemivertebra Resection for Hemimetameric Segmental Shift.

BACKGROUND: Hemimetameric segmental shift (HMMS) is defined as ≥2 contralateral hemivertebrae (HV) that are separated by at least 1 normal vertebra. Theoretically, the 2 HV tend to balance each other to produce minor spine deformities. However, curve progression has still been observed in HMMS. No research has yet specifically studied its surgical treatment. This study aimed to report efficacy of HV resection for HMMS. METHODS: From 2009 to 2015, 15 patients (5 male and 10 female) with HMMS underwent HV resection in our department. Average age at the time of surgery was 10.5 ± 4.7 years, and mean length of follow-up was 38.5 ± 7.1 months. Clinical outcomes and related complications were assessed by reviewing the medical records, operative notes, radiographic data, and scores on the Scoliosis Research Society-22 questionnaire. RESULTS: The segmental curve was 45.1° ± 10.6° preoperatively, 14.3° ± 7.8° postoperatively, and 15.3° ± 7.6° at the latest follow-up. The cranial compensatory curve was 17.1° ± 11.9°, 8.9° ± 6.3°, and 7.8° ± 6.5°. The caudal compensatory curve was 12.0° ± 11.0°, 4.5° ± 4.8°, and 4.3° ± 5.0°. Spinal balance was significantly improved in both coronal and sagittal planes and remained stable until the latest follow-up. Three domains of the Scoliosis Research Society-22 questionnaire, including general self-image, mental health, and satisfaction, were significantly improved at the latest follow-up compared with preoperative status. CONCLUSIONS: HV resection is a safe and effective treatment for HMMS that causes progressive or severe deformity.

The n-HA/PA66 Cage Versus the PEEK Cage in Anterior Cervical Fusion with Single-Level Discectomy During 7 Years of Follow-Up.

OBJECTIVE: The nano-hydroxyapatite/polyamide66 (n-HA/PA66) cage is a novel biomimetic nonmetal cage, whereas the polyetheretherketone (PEEK) cage has been widely used for decades with excellent clinical outcomes. However, there has been no long-term comparison of these 2 cages in anterior cervical reconstruction. METHODS: This retrospective study included 98 patients who underwent single-level anterior cervical decompression and fusion (ACDF) from January 2009 to June 2011 with at least 7 years of follow-up; the PEEK cage was used in 51 patients (PEEK group), whereas the n-HA/PA66 cage was used in 47 (n-HA/PA66 group). The groups were compared regarding radiographic (cage subsidence, fusion status, cervical lordosis, and segmental sagittal alignment) and clinical (10-point visual analog scale and Japanese Orthopedic Association scores) parameters preoperatively, postoperatively, and at the final follow-up. RESULTS: The n-HA/PA66 and PEEK cages had similar fusion rates at the final follow-up (97.9% vs. 98.0%). The respective cage subsidence rates in the PEEK and n-HA/PA66 cage groups were 9.8% and 10.6%. There were no significant differences between the 2 groups in mean cervical lordosis, mean interbody height, segmental sagittal alignment, cervical lordosis, and 10-point visual analog scale and Japanese Orthopedic Association scores at the final follow-up. The n-HA/PA66 cages resulted in high fusion and low subsidence rates during long-term follow-up. CONCLUSIONS: After single-level ACDF, the n-HA/PA66 cage showed similar radiographic fusion, subsidence rate, and clinical results compared with the PEEK cage during 7 years of follow-up. These results suggest that the n-HA/PA66 cage could be comparable with the PEEK cage for ACDF.

A comparison of long-term outcomes of nanohydroxyapatite/polyamide-66 cage and titanium mesh cage in anterior cervical corpectomy and fusion: A clinical follow-up study of least 8 years.

OBJECTIVES: The nanohydroxyapatite/polyamide-66 (n-HA/PA66) cage is a novel biomimetic nonmetal cage device that is now used in some medical centers, while the titanium mesh cage (TMC) is a typical metal cage device that has been widely used for decades. This study was performed to compare the long-term outcomes of these two different cages in patients undergoing anterior cervical corpectomy. PATIENTS AND METHODS: This retrospective study involved 107 patients who underwent single-level anterior corpectomy using either a TMC (n = 52) or an n-HA/PA66 cage (n = 55) for treatment of cervical degenerative disease with a minimum follow-up of 8 years. Their radiographic data (cage subsidence, fusion status, segmental sagittal alignment, and cervical spine degeneration) and clinical data [visual analog scale (VAS) and Japanese Orthopedic Association (JOA) scores] were evaluated preoperatively, postoperatively, and at the final follow-up. RESULTS: The mean duration of follow-up was 103.6 ± 6.3 months in the n-HA/PA66 group and 102.4 ± 4.6 months in the TMC group. The n-HA/PA66 group and the TMC group had similar final fusion rates (97% vs. 94%, respectively). The final n-HA/PA66 cage subsidence was 2.4 ± 1.0 mm with 18.2% subsidence of >3 mm, which was significantly lower than the respective 3.0 ± 0.7 mm and 40.4% for the TMC (p < 0.01). The n-HA/PA66 group also had better JOA scores than the TMC group (p < 0.01). No significant difference in the segmental sagittal alignment, cervical lordosis, or VAS score was observed between the two groups (p = 0.18, 0.42, and 0.17, respectively). CONCLUSIONS: The n-HA/PA66 cage is associated with excellent radiographic fusion, lower subsidence and better clinical outcomes than the TMC within 8 years after single-level anterior cervical corpectomy. With the addtional benefit of radiolucency, the n-HA/PA66 cage could be superior to the TMC in anterior cervical construction.

The efficacy of posterior hemivertebra resection with lumbosacral fixation and fusion in the treatment of congenital scoliosis: A more than 2-year follow-up study.

OBJECTIVE: Hemivertebrae (HV) located at the lower lumbar or lumbosacral region often produce early trunk imbalance and long compensatory curves. Because of the biomechanical characteristics of the lumbosacral junction, the rate of instrumentation failures at the region has always been high. Our study aimed to evaluate the results of posterior HV resection with lumbosacral fixation and fusion in the treatment of congenital scoliosis and to make a preliminary analysis of the possible risk factors for instrument failures. PATIENTS AND METHODS: From 2010 to 2015, 17 patients (7 males and 10 females) with congenital scoliosis underwent HV resection with lumbosacral fixation and fusion in our department. The mean patient age was 13.2±4.4years at surgery, and the mean follow-up time was 37.6±4.6months. Clinical outcomes and related complications were assessed by reviewing medical records, operative notes, radiographic data, and scores on the SRS-22 questionnaire. RESULTS: The mean Cobb angle of the segmental curve was 37.5°±12.7° preoperatively, 7.9°±5.5° postoperatively, and 7.9°±5.3° at the latest follow-up. The mean Cobb angle of the cranial compensatory curve was 39.2°±17.2°, 9.1°±9.5°, and 9.5°±10.8°, respectively. Trunk balance was improved in both the coronal (59.6%) and sagittal (58.6%) planes after surgery, and remained stable at the latest follow-up. Three domains of SRS-22, including self-image, mental health, and satisfaction, were significantly improved at the latest follow-up compared with preoperative status. Complications included one transient neurologic impairment, one superficial wound infection, and two implant failures. CONCLUSIONS: Early posterior HV resection with short lumbosacral fixation and fusion is effective in the treatment of HV located at lower lumbar or lumbosacral region. Delayed surgical intervention may lead to longer fusion and fixation. A long lumbosacral construct using only S1 pedicle screws as distal anchors tends to accompany a high rate of implant failures.

Does spinal deformity correction of non-dystrophic scoliosis in neurofibromatosis type I with one-stage posterior pedicle screw technique produce outcomes similar to adolescent idiopathic scoliosis?

BACKGROUND CONTEXT: The efficacy of one-stage posterior pedicle screw instrument used in the treatment of non-dystrophic scoliosis in neurofibromatosis type I (NF-1) is unknown. Also, there is no study that has directly compared the results of spinal deformity correction between non-dystrophic scoliosis in NF-1 and adolescent idiopathic scoliosis (AIS). PURPOSE: The objectives of this study were to study the efficacy of a one-stage posterior pedicle screw instrument used in the treatment of non-dystrophic scoliosis in NF-1 and to compare non-dystrophic scoliosis in NF-1 with matched AIS to illustrate the differences. STUDY DESIGN: This is a retrospective case control study. PATIENT SAMPLE: Fifteen patients with non-dystrophic scoliosis in NF-1 and 15 patients with AIS underwent a one-stage posterior surgery with the pedicle screw system. OUTCOME MEASURES: Preoperative and postoperative whole-spine radiographs were used to determine coronal and sagittal Cobb angles. Also, the distance between the C7 plumb line and the center sacral vertical line and the sagittal vertebral axis was measured to assess spinal balance. The Scoliosis Research Society (SRS)-22 questionnaire was used to evaluate functional outcomes. METHODS: We matched 15 patients with non-dystrophic scoliosis in NF-1 with patients with AIS (ratio, 1:1) for age, sex, and degree of major deformity. The overall mean age was 13.4±2.0 and 14.0±2.1 years, respectively. The NF-1 group consisted of 10 boys and 5 girls, and the AIS group consisted of 9 boys and 6 girls. The mean follow-up was 37.6±3.9 and 33.5±5.0 months, respectively. The AIS group underwent end vertebra (EV) or EV+1 fusion. The NF-1 group underwent EV+1, 2, or 3 fusion. Both coronal and sagittal Cobb angles, trunk balance, operative time, blood loss, fusion levels, length of stay, and scores on the SRS-22 questionnaire were compared between the two groups. The study was supported by the National Natural Science Foundation of China (Grant No. 81401760). There were no study-specific conflict of interest-associated biases. RESULTS: The preoperative main curve magnitude was similar between the two groups; however, the flexibility of the NF-1 group tended to be less than that of the AIS group. The rate of correction of the main curve obtained surgically (79.8% compared with 81.1%) was similar in the NF-1 and AIS groups. There were no significant differences in the loss of correction between the two groups (p>.05). Also, there were no significant differences between the groups in operative time, blood loss, fusion levels, screw number, length of stay, trunk balance, and scores on the SRS-22. There were no serious complications related to surgery in both groups. CONCLUSIONS: Despite the differences in preoperative flexibilities and fusion strategies, non-dystrophic scoliosis in NF-1 can be treated with a satisfied correction rate and progression rate similar to comparable AIS by using the one-stage posterior pedicle screw technique. Dural ectasia or thin pedicles in non-dystrophic scoliosis could make pedicle screw placement challenging.