Original Designed Uniportal-Bichannel Spinal Endoscopic System (UBiSES) for Foraminoplasty in Percutaneous Endoscopic Transforaminal Discectomy.

OBJECTIVE: The study introduced uniportal-bichannel spinal endoscopic system (UBiSES) and explored the feasibility of applying UBiSES to conduct lumbar foraminoplasty in percutaneous endoscopic transforaminal discectomy (PETD). METHODS: This is a cohort study. 36 patients confirmed as L5/S1 lumbar disc herniation (LDH) in our hospital from March, 2019 to November, 2019 were enrolled. 36 patients were divided into two groups named the UBiSES group (n = 18, male: female = 8:10) and the TESSYS group (n = 18, male: female = 10:8). The average age of the UBiSES group and the TESSYS group were 40.94 ± 12.39 years old and 39.78 ± 13.02 years old respectively. PETD via uniportal-bichannel foraminoplasty assisted by UBiSES was adopted on the UBiSES group while PETD via conventional foraminoplasty was performed on the TESSYS group. One experienced surgeon with more than 4000 cases of lumbar surgery performed PETD on all patients. The demographic data, the duration of working cannula placement (minutes), decompression time (minutes), radiation exposure time (seconds), complications, Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) scores and modified MacNab criteria were recorded and analyzed. The magnetic resonance imaging (MRI) and computed tomography (CT) were conducted to evaluate the radiographic improvement. RESULTS: PETD via lumbar foraminoplasty was successfully performed in all cases. The follow-up points were 3 months, 6 months, and 12 months. The average follow-up period of all patients was 15.78 ± 2.29 months. There was no statistic difference in age (P = 0.81), sex (P = 0.51) and follow-up (P = 0.14) between two groups. The duration of working cannula placement was 19.08 ± 2.30 min in the UBiSES group and 24.90 ± 4.71 min in the TESSYS group and there was significant difference between two groups (P < 0.05). There was no statistic difference in decompression time between the UBiSES group (44.18 ± 5.70 min) and the TESSYS group (47.46 ± 5.96 min) (P = 1.70). The radiation exposure time was 28.00 ± 4.70 s in the UBiSES group and 40.50 ± 5.73 s in the TESSYS group respectively, and has significant difference between two groups (P < 0.05). Furthermore, there was significant different in the duration of working cannula placement and radiation exposure time in male or female between the UBiSES group and the TESSYS group (P < 0.05). For male or female, no difference observed in decompression time and follow-up period between two groups. Postoperative VAS of low back and leg at every follow-up point (1 day, 3 months, 6 months, 12 months) was improved significantly in both groups compared with their preoperative VAS (P < 0.05). The postoperative ODI (3 months, 6 months, 12 months) has decreased significantly in both the UBiSES group and the TESSYS group compared with their preoperative ODI (P < 0.05). 94.44% patients received an excellent or good recovery in the UBiSES group and 88.89% for the TESSYS group. There was no poor result reported in both groups. The radiographic images showed satisfactory foraminoplasty and sufficient decompression of nerve in both groups. No postoperative complications were observed during follow-ups in the UBiSES group. Two patients in the TESSYS group experienced postoperative dysesthesia and the symptom was disappeared in 5 days and 7 days respectively with dexamethasone and neurotrophic drugs treatment. CONCLUSIONS: The original designed UBiSES could effectively and safely enlarge the foramen with an extensive surgical view and space under full-time and real-time visualization and get satisfactory efficacy.

Does anxiety influence the prognosis of percutaneous transforaminal endoscopic discectomy in the treatment of lumbar disc herniation? A preliminary propensity score matching analysis.

PURPOSE: Previous reports revealed a correlation between psychological problems and spinal surgery. There is a lack of knowledge on the effect of anxiety on the percutaneous transforaminal endoscopic discectomy (PTED) outcome at the two year follow-up. The purpose of this study is to investigate changes in anxiety after PTED among patients with lumbar disc herniation (LDH), to compare the effect of anxiety on the prognosis using propensity score matching analysis, and to identify the related parameters of anxiety. METHODS: A total of 145 patients with LDH requiring PTED surgery were included. Twenty-six LDH patients with anxiety were matched with 26 control patients utilizing propensity score matching analysis. The demographic and peri-operative data were collected and analyzed. A correlation analysis was utilized. RESULTS: Both groups achieved significant improvements in visual analogue scale (VAS) scores for pain, Japanese Orthopedic Association (JOA) scores for neurological deficit, and 36-item Short-Form Health Survey (SF-36) scores and Oswestry Disability Index (ODI) scores for quality of life. A statistical difference was detected between the pre-operative and the post-operative Zung Self-Rating Anxiety Scale scores in the anxiety cohort. However, the difference between the anxiety group and the control group was statistically significant in the aforementioned parameters. The VAS, JOA, ODI and the SF-36 scores, and the disease duration were associated with pre-operative anxiety. CONCLUSION: PTED may provide significant improvements in clinical outcomes and symptoms of anxiety. A negative impact on the patient's prognosis may be caused by the presence of anxiety. Pain severity, neurological deficit, disease duration, and quality of life were associated with anxiety.

Feasibility of Virtual Reality Combined with Isocentric Navigation in Transforaminal Percutaneous Endoscopic Discectomy: A Cadaver Study.

OBJECTIVES: Transforaminal percutaneous endoscopic discectomy (TPED) is one of the most commonly used minimally invasive spine surgeries around the world. However, conventional surgical planning and intraoperative procedures for TPED have relied on surgeons' experience, which limits its standardization and popularization. Virtual reality (VR) is a novel technology for pre-surgical planning in various fields of medicine, while isocentric navigation can guide intraoperative procedures for TPED. The present study aimed to explore the feasibility of applying VR combined with isocentric navigation in TPED on cadavers. METHODS: The surgical levels were L3 /L4 and L4 /L5 as well as L5 /S1 of both sides of each cadaver specimen. First, the surgeon manually conducted the above procedures on the left side of every specimen without preoperative simulation and isocentric navigation (Group A). Then the same surgeon conducted the VR simulation for surgical planning of the right side (Group B). After VR simulation, the same surgeon made the percutaneous punctures and placed the working channel on the right side of the specimen at all levels. RESULTS: At the L3 /L4 level, the puncture-channel time was 11.36 ± 2.13 min in Group A and 11.29 ± 2.23 min in Group B (t = 0.097, P = 0.938). The exposure time was 17.21 ± 2.91 s in Group A and 14.64 ± 1.60 s in Group B (t = 2.534, P = 0.025). At the L4 /L5 level, the puncture-channel time was 13.86 ± 3.90 min in Group A and 11.93 ± 2.95 min in Group B (t = 2.291, P = 0.039). Exposure time was 20.64 ± 3.84 s in Group A and 16.43 ± 2.47 s in Group B (t = 6.118, P < 0.01). There were 7 patients undergoing foraminotomy in Group A and 3 patients undergoing foraminotomy in Group B (t = 2.280, P = 0.236). At the L5 /S1 level, the puncture-channel time was 18.21 ± 1.85 min in Group A and 15.71 ± 3.20 min in Group B (t = 2.476, P = 0.028). Exposure time was 26.07 ± 3.17 s in Group A and 22.50 ± 2.68 s in Group B (t = 2.980, P = 0.011). There were 14 patients receiving foraminotomy in Group A and 13 patients receiving foraminotomy in Group B (t = 1.000, P = 1.000). CONCLUSIONS: Virtual reality combined with isocentric navigation is feasible in TPED. It enables precise surgical planning and improves intraoperative procedures, and has the potential for application in clinical practice.

Volume Navigation with Fusion of Real-Time Ultrasound and CT Images to Guide Posterolateral Transforaminal Puncture in Percutaneous Endoscopic Lumbar Discectomy.

BACKGROUND: The use of percutaneous endoscopic lumbar discectomy (PELD) is increasing in the treatment of lumbar disc herniations (LDH). Nerve and vessel injury may happen during the establishment of the transforaminal working channel. Also, there is usually exposure to intraop radiation when the C-arm is used to help establish the location of the transforaminal working channel. OBJECTIVE: To evaluate the accuracy and safety of the volume navigation technique for guiding transforaminal puncture in cadaver and clinical patient treatment. STUDY DESIGN: Cadaver experiment and comparative clinical research. SETTING: Changhai Hospital, the Second Military Medical University. METHOD: Volume navigation guided transforaminal puncture was performed in 15 cadavers. The registration error, time of overall puncture, ultrasound (US) observed distance between needle tip and target (DNT), and puncture error were recorded. Clinical research was performed in 63 patients who had undergone PELD. Comparative research was done between 2 groups: Those who had transforaminal puncture carried out under C-arm guidance (n = 30), and those patients whose transforaminal puncture was carried out under volume navigation guidance (n = 33). Puncture times and frequency of fluoroscopy were recorded. Both groups were evaluated with Oswestry Disability Index (ODI), and visual analog scale (VAS) before surgery at 1, 3, and 6 months, and 1 year post-surgery. RESULTS: In the cadaver experiment, mean registration error was 2.66 ± 1.10 mm; DNT 20.08 ± 1.32 mm; puncture error 2.91 ± 1.29 mm; overall time of puncture 22.10 ± 5.20 min. In the clinical patient research, puncture times and frequency of fluoroscopy were significantly lower in the volume navigation group compared with the C-arm group (P < 0.001). There were no significant differences between the 2 groups in ODI and VAS scores (P > 0.05) at different time points. LIMITATIONS: The correlation between the registration errors and the puncture errors requires further analysis. Also, due to the relatively small number of cases studied, additional cases need to be collected to obtain reliable results. CONCLUSION: The volume navigation technique can be used for PELD because it helps to guide percutaneous posterolateral transforaminal puncture accurately with reduced puncture times and intraop radiation. KEY WORDS: Lumbar disc herniation (LDH), ultrasound volume navigation (US VNav), percutaneous endoscopic lumbar discectomy (PELD), foramen, puncture.

MiR-367 negatively regulates apoptosis induced by adriamycin in osteosarcoma cells by targeting KLF4.

Diverse functions of microRNAs have been investigated in tumorigenesis in osteosarcoma (OS), involving the regulation of proliferation, invasion, migration, apoptosis and drug resistance. MiR-367 was found to be an oncogene and increased in OS. However, the function of miR-367 in drug resistance in OS cells is still unknown. In this study, we found that miR-367 was up-regulated in OS tissues and OS cell cultures. Meanwhile, treatment with adriamycin (ADR) induced apoptosis of OS cells with upregulation of miR-367. Notably, KLF4 was demonstrated to be a direct target of miR-367 by gene reporter assay, and miR-367 significantly blocked both mRNA and protein level of KLF4. In addition, overexpression of miR-367 markedly suppressed the increase of KLF4 induced by ADR in OS cells, as well as Bax and cleaved caspase-3, which were significantly reversed by anti-miR-367 transfection. Taken together, our data demonstrates that miR-367 and KLF4 play important roles in OS treatment and ADR resistance, suggesting that miR-367 is a potential biomarker of chemotherapy resistance in OS and also probably a novel therapeutic target against OS.

Identification of the relationships between sagittal plane and coronal plane curvature in guppy models.

OBJECTIVE: To explore the relationship between sagittal plane and coronal plane curvatures in guppies by investigating the curvature angles of sagittal and sagittal-coronal guppies. METHODS: After mating between 1000 spinal curvature guppies, 124 guppies (3-month old) were screened from progenies for the present study. Photos of all fishes were taken and the sagittal and coronal angles were calculated via angle measure tool of Photoshop 12.0 software. All data were analyzed by SPSS 11.0. RESULTS: In sagittal and sagittal-coronal curvature guppies, there was a significant linear correlation between sagittal angles and coronal angles. In 48 sagittal-coronal curvatures, their sagittal angles were above 40°, meanwhile, in 76 sagittal guppies, their sagittal angles were mostly below 40°. CONCLUSIONS: These findings indicated that the occurrence of coronal curvature might be later than sagittal curvature and could be influenced by other factors. Sagittal angles 40° might be involved in the onset of coronal curvature.

Whole-blood gene expression profiling in ankylosing spondylitis identifies novel candidate genes that may contribute to the inflammatory and tissue-destructive disease aspects.

We performed a comprehensive gene expression analysis to identify differentially expressed genes (DEGs) between AS (ankylosing spondylitis) and health controls. A total of 1454 DEGs were obtained, including 919 up-regulated genes and 535 down-regulated genes. There were 218 interactions and 224 pairs in the conPPI network. Topological analysis showed that 11 genes had a close relationship with AS. GO (gene ontology) functional enrichment analysis of the two modules showed that the DEGs in conPPI mainly participated in the biologic process of immune response. The KEGG pathway analysis showed that most DEGs in the two modules were enriched into cell receptor signaling pathway, natural killer cell mediated cytotoxicity and primary immunodeficiency. We hypothesized that these DEGs associated with immune response DEGs might provide basic for depth understanding of the AS development.

Expression and significance of Kruppel-like factor 6 gene in osteosarcoma.

PURPOSE: Osteosarcoma is primary malignant tumour of bone. Kruppel-like factor 6 (KLF6) is a tumor suppressor gene frequently inactivated in a number of human cancers and a ubiquitously expressed zinc-finger transcription factor. The present study aimed to first explore the relationship between the expression level of the KLF6 gene in osteosarcoma and the occurrence of bone tumours. METHODS: KLF6 mRNA and protein expression levels in osteosarcoma and normal bone tissue were assayed by real-time quantitative PCR and immunohistochemistry. KLF6 mRNA and protein expression levels in osteosarcoma cells and normal osteoblasts were detected by semi-quantitative reverse transcription PCR and Western blotting, respectively. RESULTS: Both the expression of KLF6 mRNA and protein in osteosarcoma cells and tissues were significantly lower than that in normal cells and tumour-adjacent tissues. CONCLUSIONS: KLF6 is a putative tumor suppressor gene involved in osteosarcoma which can be used as a new therapeutic target and an important marker for early diagnosis and postoperative monitoring.

Factors as predictors for thoracic and thoracolumbar/lumbar structural curves in adolescent idiopathic scoliosis.

BACKGROUND: Recent studies have demonstrated that the Lenke system is relatively efficient and consistent in classifying scoliosis curves. Basically, fusion should include the main curve and the structural minor curve. The criteria for defining the structural minor curve were established to help guide these decision-making process. The present study was designed to investigate predictors of the structural curve, and see whether it was possible to prevent the formation of the structural curve by interfering with influencing factors to decrease the fusion level. METHODS: Age, gender, Cobb angle, Perdriolle rotation, Risser sign and the number of vertebrae included in the curve, brace treatment, and curve location were recorded in 145 idiopathic scoliosis patients from July 2001 to January 2007. The patients were divided into two groups: structural and non-structural groups. Demographics and baseline characteristics were compared between the two groups as an initial screen. Logistic regression was used to analyze factors affecting the minor curve to become the structural curve. RESULTS: Compared with the non-structural group, the structural group had a higher Cobb angle ((51.34 ± 13.61)° vs. (34.20 ± 7.21)°, P < 0.001), bending angle ((33.94 ± 9.92)° vs. (8.46 ± 5.56)°, P < 0.001) and curve rotation ((23.25 ± 12.86)° vs. (14.21 ± 8.55)°, P < 0.001), and lower flexibility ((33.48 ± 12.53)% vs. (75.50 ± 15.52)%, P < 0.001). There was no significant difference in other parameters between the two groups. The results of the Logistic regression analysis showed that the Cobb angle (OR: 9.921, P < 0.001) and curve location (OR: 4.119, P = 0.016) were significant predictors of structural curve in adolescent idiopathic scoliosis. Every 10° change of Cobb angle increased the possibility of turning the minor curve into the structural curve by 10-fold. And thoracic curve showed, on the average, the possibility of becoming the structural curve about 4-fold more often than did the thoracolumbar/lumbar curve. CONCLUSIONS: Curve severity and curve location affect the minor curve's structural features in adolescent idiopathic scoliosis.

Comparison between two pedicle screw augmentation instrumentations in adult degenerative scoliosis with osteoporosis.

BACKGROUND: The operative treatment of adult degenerative scoliosis combined with osteoporosis increase following the epidemiological development. Studies have confirmed that screws in osteoporotic spines have significant lower-screw strength with more frequent screw movements within the vertebra than normal spines. Screws augmented with polymethylmethacrylate (PMMA) or with autogenous bone can offer more powerful corrective force and significant advantages. METHODS: A retrospective analysis was conducted on 31 consecutive patients with degenerative lumbar scoliosis combined with osteoporosis who had surgery from December 2000. All had a minimum of 2-year follow-up. All patients had posterior approach surgery. 14 of them were fixed with pedicle screw by augmentation with polymethylmethacrylate (PMMA) and the other 17 patients with autogenous bone. Age, sex and whether smoking were similar between the two groups. Surgical time, blood loss, blood transfusion, medical cost, post surgery ICU time, hospital day, length of oral pain medicines taken, Pre-and postoperative Oswestry disability index questionnaire and surgical revision were documented and compared. Preoperative, postoperative and final follow up Cobb angle, sagittal lumbar curve, correction rate, and Follow up Cobb loss were also compared. RESULTS: No significant differences were found between the autogenous bone group and polymethylmethacrylate group with regards to all the targets above except for length of oral pain medicines taken and surgery cost. 2 patients were seen leakage during operation, but there is neither damage of nerve nor symptom after operation. No revision was needed. CONCLUSION: Both augmentation pedicle screw with polymethylmethacrylate (PMMA) and autogenous bone treating degenerative lumbar scoliosis combined with osteoporosis can achieve a good surgical result. Less oral pain medicines taken are the potential benefits of polymethylmethacrylate augmentation, but that is at the cost of more medical spending.

Factors affecting curve flexibility in skeletally immature and mature idiopathic scoliosis.

BACKGROUND: The determination of factors affecting curve flexibility is important in idiopathic scoliosis patients with regard to the Risser sign. The objective of this retrospective study was to identify factors affecting curve flexibility in patients with skeletally immature and mature idiopathic scoliosis. METHODS: The records of all patients with idiopathic scoliosis who received surgical treatment from July 2001 to August 2008 at our hospital were screened. The Risser sign was used to separate the patients into a skeletally mature group (Risser grade = 5) and skeletally immature group (Risser grade < 5). Data recorded and compared were flexibility (%), bending angle (°), apical vertebral rotation (°), Cobb angle (°), curve location, prior use of brace treatment, and number of vertebrae in the curve. RESULTS: The study cohort consisted of 217 patients (34 males, 183 females) in the Risser grade < 5 group and 124 (21 males, 103 females) in the Risser grade = 5 group. Multiple linear regression analysis revealed that the Cobb angle and the curve location significantly affected curve flexibility in the Risser grade < 5 group, whereas in the Risser grade = 5 group, Cobb angle and age significantly affected flexibility. CONCLUSIONS: Cobb angle and curve location influence main curve flexibility in skeletally immature adolescent idiopathic scoliosis, and Cobb angle and age influence curve flexibility in skeletally mature adult scoliosis. Measurement of these values may aid in the evaluation of treatment options and preoperative planning.

Surgical treatment of adult idiopathic scoliosis: long-term clinical radiographic outcomes.

More adults are suffering from adult idiopathic scoliosis and seeking treatment for their spinal deformities. Adult idiopathic scoliosis can lead to painful spinal osteoarthritis, progressive deformity, spinal stenosis with radiculopathy, muscle fatigue from coronal and sagittal plane imbalance, and psychological effects with a visible deformity. Primary treatment of such conditions is conservative; however, some patients are resistant to conservative treatment or are not candidates for it, and they require surgery. Back pain is likely the most common indication for surgical treatment of scoliosis in adult patients. Pedicle screws offer 3-column purchase and a longer arm compared with hook placement on the lamina. This study is a retrospective analysis of a consecutive series of patients with adult idiopathic scoliosis who were treated with pedicle screw placement. Significant back pain relief and satisfaction can be achieved and maintained over the long term. Restoration of coronal and sagittal balance, or improvement thereof, was achieved in all patients with balance problems. This study clarified several important characteristics of adult scoliosis, and we believe that useful conclusions can be drawn regarding its surgical indications and strategies: (1) pedicle screw construct can gain effective results for treatment of adult idiopathic scoliosis due to its perceived superior power of correction; (2) younger patients present for surgery for different reasons than older patients (progressive deformity or pain); and (3) pain improvement is a more reliable outcome in older patients than younger patients, although younger patients rarely have severe pain symptoms.

Using side-bending radiographs to determine the distal fusion level in patients with single thoracic idiopathic scoliosis undergoing posterior correction with pedicle screws.

STUDY DESIGN: Prospective. OBJECTIVES: To evaluate a strategy to determine the distal fusion level in posterior pedicle screw correction of single thoracic idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: No standard method for selecting the lowest instrumented vertebra (LIV) for the correction of thoracic adolescent idiopathic scoliosis with posterior all-pedicle screw instrumentations exists. METHODS: Thirty-eight patients with single right thoracic (Lenke 1A) adolescent idiopathic scoliosis undergoing posterior pedicle screw fixation were studied. The LIV was determined using guidelines based on preoperative side-bending radiographs. In brief, (1) the whole thoracic Cobb curve should be included in the fusion mass, and the LIV should not be superior to the lower-end vertebra of the Cobb measurement. (2) On the right side-bending radiographs, the LIV should be derotated to neutral in skeletally immature (Risser 0 to 3) patients and the disc immediately below the LIV must open on the left side by at least 5 degrees. (3) On the left side-bending radiographs, the disc immediately below the LIV must be open on the right side by at least 0 degree. The first segment meeting the criteria when proceeding from the lower-end vertebra caudally is chosen as the LIV. Outcomes were based on the standing radiographs. RESULTS: Minimum follow-up was 2 years. The mean preoperative thoracic curve was 48.4±9.2 degrees and 12.6±6.1 degrees at final follow-up, resulting in a mean correction of 74.7%±8.5%. The mean preoperative compensatory lumbar curve of 23.7±7.5 degrees was 6.3±4.8 degrees at final follow-up. A change in lumbar lordosis from -41.2±11.9 degrees preoperatively to -38.2±9.9 degrees at final follow-up occurred. All patients achieved coronal balance and no decompensation or adding-on phenomenon was observed. Compared with the recommended fusion end by the Harrington stable zone method, 86.9% patients were saved 1 or more motion segment. CONCLUSIONS: The method described was effective in obtaining satisfactory curve correction, adequate trunk balance, and preservation of motion segments.

Using precisely controlled bidirectional orthopedic forces to assess flexibility in adolescent idiopathic scoliosis: comparisons between push-traction film, supine side bending, suspension, and fulcrum bending film.

STUDY DESIGN: A prospective study. OBJECTIVE: To validate the effectiveness of push-traction film (PTF) in assessment of curve flexibility in adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: There is no agreement among surgeons about the most advantageous method in flexibility evaluation of scoliosis. As all methods available provide the orthopedic force from one direction and use a single torque, it is difficult for them to achieve the postoperative correction; also they could not meet the needs for different types of curves. METHODS: Precisely controlled bidirectional (push and traction) orthopedic forces were applied for curve flexibility evaluation in 31 consecutive adolescent idiopathic scoliosis patients. The correction rate (CR) of postoperation, supine side-bending, suspension, and fulcrum bending radiographs were compared with PTF in instrumented main thoracic (MT) and thoracolumbar/lumbar curves. Correlation and linear regression analyses were also been done to find the best predictor among the four methods. RESULTS: In MT group, CR of PTF was significantly higher than that of side bending (P = 0.010) and suspension (P = 0.000) but not significantly different from that of fulcrum bending (P = 0.335). In TL/L group, CR of PTF was significantly higher than that of suspension (P = 0.000), but not significantly different from that of side bending (P = 0.681) and fulcrum bending (P = 0.382). There was no significant difference between CR of PTF and postoperation in both MT (P = 0.122) and TL/L (P = 0.068) groups. Correlation and linear regression analyses showed that PTF provided the highest correlation of the four methods, with the postoperative angle in both MT (r = 0.957) and MT/L group (r = 0.779). CONCLUSION: To our knowledge, this was the first report about using precisely controlled bidirectional correction forces for curve flexibility evaluation. Although it did not achieve the best CR among the four methods studied, correlation and regression analyses confirmed that PTF was a more stable and accurate method to predict flexibility. We believe that further exploration of a more rational push-traction force ratio would help to obtain a better flexibility.

Learning curve of computer-assisted navigation system in spine surgery.

BACKGROUND: Spine surgery using computer-assisted navigation (CAN) has been proven to result in low screw misplacement rates, low incidence of radiation exposure and excellent operative field viewing versus the conventional intraoperative image intensifier (CIII). However, as we know, few previous studies have described the learning curve of CAN in spine surgery. METHODS: We performed two consecutive case cohort studies on pedicel screw accuracy and operative time of two spine surgeons with different experience backgrounds, A and B, in one institution during the same period. Lumbar pedicel screw cortical perforation rate and operative time of the same kind of operation using CAN were analyzed and compared using CIII for the two surgeons at initial, 6 months and 12 months of CAN usage. RESULTS: CAN spine surgery had an overall lower cortical perforation rate and less mean operative time compared with CIII for both surgeon A and B cohorts when total cases of four years were included. It missed being statistically significant, with 3.3% versus 4.7% (P = 0.191) and 125.7 versus 132.3 minutes (P = 0.428) for surgeon A and 3.6% versus 6.4% (P = 0.058), and 183.2 versus 213.2 minutes (P = 0.070) for surgeon B. In an attempt to demonstrate the learning curve, the cases after 6 months of the CAN system in each surgeon's cohort were compared. The perforation rate decreased by 2.4% (P = 0.039) and 4.3% (P = 0.003) and the operative time was reduced by 31.8 minutes (P = 0.002) and 14.4 minutes (P = 0.026) for the CAN groups of surgeons A and B, respectively. When only the cases performed after 12 months using the CAN system were considered, the perforation rate decreased by 3.9% (P = 0.006) and 5.6% (P < 0.001) and the operative time was reduced by 20.9 minutes (P < 0.001) and 40.3 minutes (P < 0.001) for the CAN groups of surgeon A and B, respectively. CONCLUSIONS: In the long run, CAN spine surgery decreased the lumbar screw cortical perforation rate and operative time. The learning curve showed a sharp drop after 6 months of using CAN that plateaued after 12 months; which was demonstrated by both perforation rate and operative time data. Careful analysis of the data showed CAN is especially useful for less experienced surgeon to reduce perforation rate and intraoperative time, although further comparative studies are anticipated.

[Analysis of posterior pedicle screw-only constructs in surgical treatment of adolescent idiopathic scoliosis with a minimum three-year follow-up].

OBJECTIVE: To evaluate clinical outcomes of a group of adolescent idiopathic scoliosis (AIS) patients undergoing posterior pedicle screw-only instrumentations. METHODS: Between April 2002 and July 2006, 121 AIS patients (93 female and 28 male, average age at operation was 15.5 years which ranged from 10 to 20 years) received posterior pedicle screw-only instrumentation and fusion. All the patients were evaluated by the various-parameters measured in X-ray films before and after surgery, including Cobb angle on coronal plane, Cobb angle on sagittal plane, clavicle angle and shoulder height difference, lowest instrumented vertebrae (LIV) angulation, proximal junction kyphotic angle, the distances of central sacral vertical line (CSVL) to the LIV, to the apical vertebra and to the C(7) plumb line respectively. Complications were followed. RESULTS: An average of (11.0 + or - 1.5) levels was fused. An average coronal correction of proximal thoracic curve was 41.8%, of thoracic curve was 70.8%, of thoracolumbar/lumbar curves was 74.0%. No significant change was found in sagittal alignment. Shoulder balance and apex vertebral to central sacral line were restored well. There were no pseudoarthroses and loss of correction during the follow-ups. One adding-on, 4 proximal thoracic decompensation and 15 proximal junction kyphosis were found during the follow-ups. CONCLUSION: Posterior pedicle screw-only instrumentation and fusion has excellent radiographic and clinical results with minimal complications in the surgical treatment of AIS.

Adapted simplified Chinese (mainland) version of Scoliosis Research Society-22 questionnaire.

STUDY DESIGN: Validation study to define validity and reliability of an adapted and translated questionnaire. OBJECTIVE: This study attempted to validate the traditional Chinese (Hong Kong) version of the modified Scoliosis Research Society (SRS) Outcomes Instrument, SRS-22, into simplified Chinese for use in mainland China. SUMMARY OF BACKGROUND DATA: Although a traditional Chinese (Hong Kong) adaptation of the SRS-22 has been previously validated, no culturally adapted, validated SRS-22 exists for use in mainland China. METHODS: Adhering to International Quality of Life Assessment Project guidelines, the adapted traditional Chinese SRS-22 was translated into simplified Chinese while referencing the original English questionnaire. To examine the psychometric properties and clinical application of the adapted simplified Chinese SRS-22, a survey was conducted in a group of randomly selected 87 patients previously surgically treated at an outpatient clinic. Reliability assessment of the simplified Chinese version of the SRS-22 was determined by calculating Cronbach's alpha and intraclass coefficient (ICC) values. Concurrent validity was evaluated by comparing SRS-22 domains with relevant domains of the simplified Short-Form-36 questionnaire; correlation was made using Pearson correlation coefficients. RESULTS: Cronbach's alpha, applied to each of the 22 questions of the adapted SRS-22, revealed very satisfactory internal consistency (Cronbach's alpha = 0.80-0.89) for function/activity and pain, and good consistency (Cronbach's alpha = 0.50-0.79) for the remaining domains. The test/retest reproducibility was found to be good (ICC > or =0.40-0.75) in the function/activity domain, and excellent (ICC > or =0.75) in the remaining domains. In terms of concurrent validity, 3 domains had excellent correlation, while 10 had good correlation, and 21 had moderate correlation. DISCUSSION: The authors report the validation of a simplified Chinese SRS-22 for use in mainland China, which is culturally relevant, reliable, repeatable, psychometrically sound, and suitable for immediate clinical use.

Abnormal ossification as a cause the progression of adolescent idiopathic scoliosis.

Although, there is no generally accepted scientific theory for the etiology of adolescent idiopathic scoliosis (AIS), the relative anterior spinal column overgrowth has been postulated as a mechanism of AIS progression by many morphological studies. The normal spinal growth involves both kinds of ossification: endochondral and membranous ossification. Considering the uncoupled anterior-posterior column growth of AIS patients, the uncoupled endochondral-membranous ossification could possibly play an important role in the progression of AIS. Meanwhile, other observations found that the uncoupling of ossification was not limited to the spinal column, but rather a systemic phenomenon. This consideration leads us to carefully dissect the underlying abnormal molecular pathways, cytokines or receptors of ossification, such as BMP-Smads, Runx2, FGFR-3, and will raise the hope to detect the AIS progression potentiality and help to formulate the appropriately personalized treatment strategy for patients.