Comparison of the clinical outcomes of VBE-TLIF versus MIS-TLIF for single-level degenerative lumbar diseases.

OBJECTIVE: This research aims to compare the clinical outcomes of VBE-TLIF and MIS-TLIF for the treatment of patients with single-level degenerative lumbar diseases. METHODS: Ninety patients were enrolled in this study. The estimated blood loss, operation time, postoperative hospitalization days, time to functional exercise, amount of surgical drain and inflammatory index were recorded. The visual analog scale, Oswestry dysfunction index and modified MacNab criteria were used to assessed the patient's back and leg pain, functional status and clinical satisfaction rates. RESULTS: The average operation time of the VBE-TLIF group was longer than that of the MIS-TLIF group. The time for functional exercise, length of hospital stay, estimated blood loss and amount of surgical drain in the VBE-TLIF group were relative shorter than those in the MIS-TLIF group. Additionally, the levels of CRP, neutrophil, IL-6 and CPK in the VBE-TLIF group were significantly lower than those in the MIS-TLIF group at postoperative days 1 and 3, respectively (P < 0.001). Patients undergoing VBE-TLIF had significantly lower back VAS scores than those in the MIS-TLIF group on postoperative days 1 and 3 (P < 0.001). No significant differences were found in the clinical satisfaction rates (95.83 vs. 95.24%, P = 0.458) or interbody fusion rate (97.92 vs. 95.24%, P = 0.730) between these two surgical procedures. CONCLUSIONS: Both VBE-TLIF and MIS-TLIF are safe and effective surgical procedures for patients with lumbar diseases, but VBE-TLIF technique is a preferred surgical procedure with merits of reduced surgical trauma and quicker recovery.

Proximal junctional kyphosis in Lenke 5C adolescent idiopathic scoliosis after selective posterior thoracolumbar/lumbar fusion: risk factors and predictive index.

BACKGROUND: Although several studies have reported that selective posterior thoracolumbar/lumbar (TL/L) fusion can yield satisfactory results in Lenke 5C adolescent idiopathic scoliosis (AIS), the proximal junctional kyphosis (PJK) is still a common complication that occurs after surgery. The purpose of this study is to analyse the risk factors for postoperative proximal junctional kyphosis in Lenke 5C patients who underwent selective posterior TL/L fusion and explore whether PJK can be predicted. METHODS: A total of 83 AIS patients with Lenke 5C curves who met the inclusion criteria were analysed. All patients were divided into two groups based on the occurrence of postoperative PJK. Univariate and multivariate analyses were used to identify independent factors significantly associated with PJK, and an PJK index was proposed and verified. RESULTS: PJK was observed in 27 of 83 (32.5%) patients in the study. Preoperative thoracic kyphosis (TK) and the immediate postoperative proximal junctional angle (PJA) were the primary factors identified by the binary logistic regression analysis. The PJK index was defined as 1.1× preoperative TK + 2.3× immediate postoperative PJA. The receiver operating characteristics curve indicated that the occurrence rate of PJK was 85% and non-occurrence rate was 82% when the PJK index was greater than 42. CONCLUSION: Large preoperative TK and a large immediate postoperative PJA play important roles in the development of PJK in Lenke 5C patients treated with selective posterior thoracolumbar/lumbar fusion. The PJK index can be used to predict the occurrence of PJK with high accuracy. To prevent the occurrence of PJK, we should pay attention to the TLK, and preserving more posterior proximal intervertebral elements at the upper instrumented vertebral level would be an important part of corrective surgery; however, moderate correction of the lumbar curve is recommended.

Minimally invasive transforaminal lumbar interbody fusion by a novel two-medium compatible bichannel endoscopy system, technique note and preliminary clinical results.

PURPOSE: Our team designed a novel two-medium compatible bichannel endoscopy system for spinal surgery, V-shape bichannel endoscopy (VBE) system. Hereby, this study will introduce minimally invasive transforaminal lumbar interbody fusion (TLIF) with VBE system and report its preliminary clinical results. METHODS: Fifty-two participants, who accepted VBE-assisted TLIF surgery (VBE-TLIF) in our hospital were included in this study. The duration of operation, off-bed time, and days of hospitalization were recorded. Besides, the patient's preoperative and postoperative pain were evaluated via visual analog scale (VAS), the functional status was evaluated via Oswestry dysfunction index (ODI) and modified MacNab criteria. Patients were asked to follow-up in the outpatient department at the 3rd, 6th, 12th, and 24th month after surgery. X-ray or CT was examined to evaluate the internal fixation position and interbody fusion result. RESULTS: All patients received unilateral decompression with an average operation duration of 178.49 ± 27.49 min. After the surgery, their VAS score of leg pain and back pain reduced significantly. At the last follow-up, the VAS score of leg pain and back pain was 0.80 ± 0.69 and 0.86 ± 0.75 separately. The difference shows statistically significant with p < 0.05. At the last follow-up, the ODI was 15.20 ± 5.75. According to modified MacNab criteria, 39 patients rated their function as excellent, and 10 patients were good. The overall satisfaction rate reached 94%. CONCLUSION: The VBE system reported in the current study can complete TLIF surgery safely and effectively.

Muscone Ameliorates Ovariectomy-Induced Bone Loss and Receptor Activator of Nuclear Factor-κb Ligand-Induced Osteoclastogenesis by Suppressing TNF Receptor-Associated Factor 6-Mediated Signaling Pathways.

Postmenopausal osteoporosis is caused by the deficiency of estrogen, which breaks bone homeostasis and induces levels of pro-inflammatory cytokines. Muscone is a potent anti-inflammatory agent and is used to treat bone fracture in traditional Chinese medicine. However, its anti-osteoclastogenic effects remain unclear. For in vitro study, morphology tests of osteoclastogenesis were firstly performed. And then, factors in RANK-induced NF-κB and MAPK pathways were examined by RT-PCR and Western blot, and the binding of TNF receptor-associated factor (TRAF)6 to RANK was inspected by coimmunoprecipitation and immunofluorescence staining. For in vivo experiments, C57BL/6 ovariectomized (OVX) mice were used for detection, including H&E staining, TRAP staining, and micro CT. As a result, muscone reduced OVX-induced bone loss in mice and osteoclast differentiation in vitro, by inhibiting TRAF6 binding to RANK, and then suppressed NF-κB and MAPK signaling pathways. The expression of the downstream biomarkers was finally inhibited, including NFATc1, CTR, TRAP, cathepsin K, and MMP-9. The inflammatory factors, TNF-a and IL-6, were also reduced by muscone. Taken together, muscone inhibited the binding of TRAF6 to RANK induced by RANKL, thus blocking NF-kB and MAPK pathways, and down-regulating related gene expression. Finally, muscone inhibited osteoclastogenesis and osteoclast function by blocking RANK-TRAF6 binding, as well as downstream signaling pathways in vitro. Muscone also reduced ovariectomy-induced bone loss in vivo.

Reduced Puncture Time and Radiation Exposure of Percutaneous Transpedicular Puncture with Electronic Conductivity Device: A Randomized Clinical Trial.

OBJECTIVES: The present study introduced an electronic conductivity device (ECD) to reduce time of percutaneous transpedicular puncture and frequency of patient valid radiation exposure in percutaneous kyphoplasty (PKP) or percutaneous vertebroplasty (PVP). METHODS: A randomized self-control clinical study was undertaken. Medical records of patients with vertebral compression fractures (VCFs) for bilateral PKP or PVP were collected, and each side was performed randomly with ECD or conventional trocar. RESULTS: We enrolled 61 patients (44 women, 17 men) with 75 vertebras with VCF. Compared with the conventional fluoroscopy group, significant reductions in puncture time (504.33 ± 152.03 vs. 652.68 ± 167.60 seconds; P < 0.001) and fluoroscopy frequency (5.11 ± 1.23 vs. 8.15 ± 1.83; P < 0.001) for each percutaneous puncture were observed in the ECD group. When compared with the VCFs ≤50% group, the 2 indexes in the VCFs >50% group were significantly increased. And in the ECD group, the learning curve in the VCFs >50% group showed a steeper decreasing trend than that in the VCFs ≤50% group. No complications were observed in any patient. CONCLUSIONS: ECD could reduce puncture time of percutaneous transpedicular puncture and exposure of radiation in PVP and PKP. ECD has more benefits in complicated transpedicular puncture in patients with vertebral compression >50%.

Does spinal fusion to T2, T3, or T4 affects sagittal alignment of the cervical spine in Lenke 1 AIS patients: A retrospective study.

The aim of this stusy was to investigate whether spinal fusion to T2, T3, or T4 affects sagittal alignment of the cervical spine in Lenke 1 adolescent idiopathic scoliosis (AIS) patients.A retrospective study comprised of 64 Lenke 1 AIS patients was performed to assess the radiographic and clinical outcome. According to the upper instrumented vertebrae (UIV) (T2, T3, or T4), the patients were divided into 3 groups. Comparison analyses were performed among these 3 groups of patients as between pre-op, immediate post-op, and final follow-up, as well as between these groups.Between groups, comparison analyses did not detect a statistical difference in cervical lordosis (CL) preoperatively (P = .501), immediately after surgery (P = .795), and at follow-up (P = .510). Immediately after surgery, CL increased significantly in all groups (T2, P = .004, T3, P < .001 and T4, P = .002 respectively). Compared with immediate postoperatively, CL at final follow-up increased in T2 group (P = .037), and T4 group (P = .010). Furthermore, CL at follow-up was significantly correlated with the following parameters: preoperative (coronal plane balance [r = .349, P = .004], pelvic tilt [r = 0.347, P = .004), pelvic incidence [r = 0.261, P = .031], and CL [r = 0.471, P < .001]) immediately postoperative (CL [r = 0.946, P < .001], T1-slope [r = -0.646, P < .001], and thoracic kyphosis [TK] [r = -0.353, P = .003]), and at follow-up (TK [r = -0.342, P = .004], and T1-slope [r = -0.821, P < .001]). However, there was no significant correlation between a selection of UIV and CL at follow-up (r = 0.031, P = .802). Moreover, Scoliosis Research Society (SRS-22) scores between groups were similar preoperatively (P = .242), immediately after surgery (P = .828), and at follow-up (P = .219).In Lenke 1 AIS patients, the selection of UIV mainly affects the coronal plane, especially shoulder balance. Fusion to T2, T3, or T4 did not affect the alignment of the cervical spine, and the SRS-22 score. LEVEL OF EVIDENCE: Level IV.

Basic study for ultrasound-based navigation for pedicle screw insertion using transmission and backscattered methods.

The purpose of this study was to understand the acoustic properties of human vertebral cancellous bone and to study the feasibility of ultrasound-based navigation for posterior pedicle screw fixation in spinal fusion surgery. Fourteen human vertebral specimens were disarticulated from seven un-embalmed cadavers (four males, three females, 73.14 ± 9.87 years, two specimens from each cadaver). Seven specimens were used to measure the transmission, including tests of attenuation and phase velocity, while the other seven specimens were used for backscattered measurements to inspect the depth of penetration and A-Mode signals. Five pairs of unfocused broadband ultrasonic transducers were used for the detection, with center frequencies of 0.5 MHz, 1 MHz, 1.5 MHz, 2.25 MHz, and 3.5 MHz. As a result, good and stable results were documented. With increased frequency, the attenuation increased (P<0.05), stability of the speed of sound improved (P<0.05), and penetration distance decreased (P>0.05). At about 0.6 cm away from the cortical bone, warning signals were easily observed from the backscattered measurements. In conclusion, the ultrasonic system proved to be an effective, moveable, and real-time imaging navigation system. However, how ultrasonic navigation will benefit pedicle screw insertion in spinal surgery needs to be determined. Therefore, ultrasound-guided pedicle screw implantation is theoretically effective and promising.

Application of 3D rapid prototyping technology in posterior corrective surgery for Lenke 1 adolescent idiopathic scoliosis patients.

A retrospective study to evaluate the effectiveness of 3-dimensional rapid prototyping (3DRP) technology in corrective surgery for Lenke 1 adolescent idiopathic scoliosis (AIS) patients. 3DRP technology has been widely used in medical field; however, no study has been performed on the effectiveness of 3DRP technology in corrective surgery for Lenke 1 AIS patients. Lenke 1 AIS patients who were preparing to undergo posterior corrective surgery from a single center between January 2010 and January 2012 were included in this analysis. Patients were divided into 2 groups. In group A, 3-dimensional (3D) printing technology was used to create subject-specific spine models in the preoperative planning process. Group B underwent posterior corrective surgery as usual (by free hand without image guidance). Perioperative and postoperative clinical outcomes were compared between 2 groups, including operation time, perioperative blood loss, transfusion volume, postoperative hemoglobin (Hb), postoperative complications, and length of hospital stay. Radiological outcomes were also compared, including the assessment of screw placement, postoperative Cobb angle, coronal balance, sagittal vertical axis, thoracic kyphosis, and lumbar lordosis. Subgroup was also performed according to the preoperative Cobb angle: mean Cobb angle <50° and mean Cobb angle >50°. Besides, economic evaluation was also compared between 2 groups. A total of 126 patients were included in this study (group A, 50 and group B, 76). Group A had significantly shorter operation time, significantly less blood loss and transfusion volume, and higher postoperative Hb (all, P < 0.001). However, no significant differences were observed in complication rate, length of hospital stay, and postoperative radiological outcomes between 2 groups (all, P>0.05). There was also no significant difference in misplacement of screws in total populations (16.90% vs 18.82%, P = 0.305), whereas a low misplacement rate of pedicle screws was observed in patients whose mean Cobb angle was >50° (9.15% vs 13.03%, P = 0.02). Besides, using 3DRP increased the economic burden of patients (157,000 ±â€Š9948.85 Ren Min Bi (RMB) vs 152,500 ±â€Š11,445.52 RMB, P = 0.03). Using the 3D printing technology before posterior corrective surgery might reduce the operation time, perioperative blood loss, and transfusion volume. There did not appear to be a benefit to using this technology with respect to complication rate and postoperative radiological outcomes; however, 3D technology could reduce the misplacement rate in patients whose preoperative mean Cobb angle was >50°. Besides, it also increased the patients' hospital cost. Therefore, future prospective studies are needed to elucidate the efficacy of this emerging technology.

Screening of diagnostic markers for osteosarcoma.

Osteosarcoma, which is the most common type of highly malignant bone tumor in children and adolescents, has poor diagnosis and 2-year survival rates of 15-20% following surgery or radiotherapy, and has therefore generated marked attention. In order to investigate the potential biomarkers for diagnosing osteosarcoma, the expression profiling data from normal and disease tissues were compared, respectively, and the differentially­expressed genes were analyzed by three different statistical tests. Interacting proteins were determined and an interaction network was constructed by Search Tool for the Retrieval of Interacting Genes database. Subsequently, the protein interaction network was decomposed and Gene Otology annotation using Cytoscape, Mcode and Bingo, was conducted on the function modules. Finally, three differentially­expressed genes GJA1, COL1A2 and COL5A2 were identified, and an interaction network was successfully generated with COL1A2 and COL5A2 at the core. From the results, it was observed that COL1A2 and COL5A2 interact with a number of genes of the matrix metalloprotease (MMP) family, including MMP1, MMP2, MMP3 and MMP14, TGFß and RUNX2. Furthermore, these genes have been confirmed to be important in the tumorigenesis of osteosarcoma. It was hypothesized that the upregulation of the COL gene family may be considered as a diagnostic marker for osteosarcoma and collagen may be administered as a therapy.

Fuzzy clustering analysis of osteosarcoma related genes.

Osteosarcoma is the most common malignant bone-tumor with a peak manifestation during the second and third decade of life. In order to explore the influence of genetic factors on the mechanism of osteosarcoma by analyzing the inter relationship between osteosarcoma and its related genes, and then provide potential genetic references for the prevention, diagnosis and treatment of osteosarcoma, we collected osteosarcoma related gene sequences in Genebank of National Center for Biotechnology Information (NCBI) and local alignment analysis for a pair of sequences was carried out to identify the measurement association among related sequences. Then fuzzy clustering method was used for clustering analysis so as to contact the unknown genes through the consistent osteosarcoma related genes in one class. From the result of fuzzy clustering analysis, we could classify the osteosarcoma related genes into two groups and deduced that the genes clustered into one group had similar function. Based on this knowledge, we found more genes related to the pathogenesis of osteosarcoma and these genes could exert similar function as Runx2, a risk factor confirmed in osteosarcoma, this study may help better understand the genetic mechanism and provide new molecular markers and therapies for osteosarcoma.

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.

Surgical treatment of transverse patella fractures by the cable pin system with a minimally invasive technique.

BACKGROUND: Transverse patella fractures are the most common type of patella fractures. Minimally invasive surgical technique for treatment of transverse patella fractures with the Cable Pin System has not been previously reported. METHODS: Thirty-four patients with displaced transverse fractures of the patella were included in this prospective study and were operatively treated by the Cable Pin System with a minimally invasive technique. Postoperative evaluation was based on radiographs, Visual Analog Scale of pain, range of motion, and Bostman grading scale. RESULTS: A total of 31 patients were finally included, with an average follow-up period of 21 months. The average operation time was 48 minutes. Intraoperative fluoroscopy was used for 2 to 4 times (average: 2.4 times). Radiographic evidence of solid fracture union was observed in all cases in a mean period of 7.2 weeks. The Visual Analog Scale score for pain was 3.3 ± 1.4 and 1.5 ± 1.3 at 4 weeks after surgery and when radiographic fracture healing was achieved, respectively. Twenty-nine patients achieved full knee range of motion, while two patients had 10° loss of full flexion at the final follow-up visit. The average Bostman score was 29.1/30 (range, 27-30) at 1 year after surgery, and an evaluation of "excellent" was observed in 30 patients at the final follow-up visit. CONCLUSION: Surgical treatment of transverse patella fractures by the Cable Pin System with a minimally invasive technique was shown to provide satisfactory clinical results and excellent knee functions, with less pain and low incidence of complications. It could be a new option for treatment of transverse patella fractures.

All-pedicle-screw versus hybrid hook-screw instrumentation for posterior spinal correction surgery in adolescent idiopathic scoliosis: a curve flexibility matched-pair study.

INTRODUCTION: Comparisons of all-pedicle-screw (PS) and hybrid hook-screw (HS) instrumentation for the treatment of adolescent idiopathic scoliosis (AIS) have produced conflicting results. The aim of this study was to compare all-pedicle-screw and hybrid hook-screw instrumentation for the treatment of AIS using a matched-pair study design in which preoperative flexibility was matched. METHODS: In this retrospective study conducted at one medical center, 21 all-pedicle-screw/hybrid hook-screw pairs of Lenke type I AIS patients matched for age, height, weight, body mass index, sex, and preoperative curve flexibility who had been treated at our institution from January 2000 to October 2006 were selected. Postoperative and 2-year postoperative coronal curve correction, postoperative kyphosis, blood transfusion needs, operation time, and hospital cost were measured and analyzed statistically. RESULTS: The PS group compared with the HS group had better postoperative correction (P = 0.0231) and 2-year coronal curve correction (P = 0.016). While statistically significant (P = 0.0073), the postoperative Cobb angle was only 3° less in the PS group, Maintenance of correction after 2 years was better in the PS group (P = 0.0016). The PS group had less blood loss (P < 0.0001) and shorter operation time (P < 0.0001), but the hospital cost for the PS group was higher (P < 0.0001). CONCLUSIONS: All-pedicle-screw and hybrid hook-screw instrumentations are comparable with regard to curve correction, but all-pedicle screw instrumentation reduces blood loss during surgery and shortens the operation time, which may help shorten healing time.

Associations between body mass and the outcome of surgery for scoliosis in Chinese adults.

BACKGROUND: In this study we intended to prove that being overweight has an unfavorable impact on the surgical treatment outcome of adult idiopathic scoliosis (AdIS). METHODS: This is a retrospective study on the surgical treatment of seventy-one more than 30 years old (58 females and 13 males; mean age 42.9±12.2) idiopathic scoliotic patients with a minimum follow up of at least 2 years. The patients were divided into an overweight group (BMI≥23) and a non-overweight group (BMI<23). Preoperative, postoperative first erect and final follow-up radiographic measures, perioperative data, the Oswestry disability index (ODI), and the visual analog scale (VAS) were reviewed and compared. FINDINGS: In the overweight group, no significant differences in radiographic measures, perioperative data, preoperative comorbidities, or postoperative complications, except for the more frequent concomitance of preoperative thoracic kyphosis 37.9±7.7 vs. 26.5±11.8 (P = 0.000) and thoracolumbar kyphosis 14.9±10.1 overweighted group vs. 6.5±9.9 non-overweighted group respectively (P = 0.002) were found. A higher morbidity of hypertension 36.8% vs. 9.6% (P = 0.004) was also observed in the overweight group. Postoperative ODI and VAS improved significantly in both groups compared to pre-operative values. The postoperative ODI of the overweight group (19.6±12.4) was significantly higher than that of the non-overweight group (12.4±7.9) (P = 0.022). CONCLUSIONS: Overweight adult idiopathic scoliotic patients had more frequent concomitance of preoperative thoracic kyphosis and thoracolumbar kyphosis and more serious postoperative pain. However, BMI did not affect the outcomes of surgical correction for coronal and sagittal scoliotic deformity and their postoperative complication rates were not significantly affected.

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.

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.

Effect of preoperative brace treatment on quality of life in adolescents with idiopathic scoliosis following corrective surgery.

Bracing is frequently used for the treatment of adolescent idiopathic scoliosis. Such treatment is not always effective, and corrective surgery may be warranted. Brace treatment has been suggested to negatively affect quality of life. This study assessed postoperative quality of life and surgical outcome in Chinese patients with adolescent idiopathic scoliosis and failed brace treatment. Ninety-four patients with adolescent idiopathic scoliosis who underwent simple posterior corrective surgery and pedicle screw fixation were studied. The patients were divided into 2 groups: brace and surgery treatment (BS group) and surgery with no brace treatment (S group). Radiological parameters were assessed preoperatively, immediately postoperatively, and >2 years postoperatively. Postoperative quality of life was determined using the Scoliosis Research Society-22 (SRS-22) questionnaire. The preoperative minor curve Cobb angle was significantly greater in the BS group (34.9 degrees vs 29.4 degrees ; P=.037). Postoperative radiological parameters in the coronal and sagittal planes were similar. There were a significantly higher number of fused vertebrae in BS compared to S group patients (10.3 vs 9.6; P=.044). There were no significant postoperative differences between groups in function/activity, pain, mental health, or satisfaction of management as determined by the SRS-22. Self-image/appearance scores were significantly higher in BS compared to S group patients (4.0 vs 3.8; P=.010). Preoperative brace treatment may be a risk factor for minor curve progression but does not appear to significantly influence surgical outcome. Postoperative self-perceived quality of life is not negatively affected by preoperative brace treatment.

Posterior pedicle screws combined with shortening and release techniques for lumbar and thoracolumbar adolescent idiopathic scoliosis.

OBJECTIVE: To prospectively evaluate the clinical and radiographic effects of posterior surgery with wide posterior shortening release and segmental pedicle screws techniques in a consecutive group of patients with thoracolumbar /lumbar adolescent idiopathic scoliosis. METHODS: Between April 2002 and July 2005, 114 patients (86 women and 28 men) were enrolled in this study. There were 72 Lenke type 5, 32 Lenke type 6, and 10 Lenke type 3C curves. Radiographic parameters such as coronal plane Cobb angle; lordosis angle; lowest instrumented vertebrae (LIV) angulation; and the distances from the central sacral vertical line (CSVL) to the LIV, to the apical vertebra and to the C7 plumb line, were analyzed. Complication rates were also recorded during follow-up. RESULTS: The average coronal correction was from 61° to 13° (78.6%). In the sagittal plane, lumbar lordosis was normalized from 36° with a wide range (23°-67°) to 42° with a normal range (34°-55°). The LIV had 79% correction of coronal angulations. The center sacral line to LIV was improved from 2.3 cm to 0.5 cm, apex to center sacral line from 5.0 cm to 1.6 cm, and CSVL from 2.7 cm to 0.8 cm. A total of 1460 pedicle screws were placed safely, average 9.6 levels (5-14) were fused. The patients were followed up for an average of 30 months (range, 12-50). There was excellent maintenance of correction at final follow-up. CONCLUSION: Wide posterior release and segmental pedicle screw instrumentation has excellent radiographic and clinical results with minimal complications.