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.

[Clinical application of Wallis interspinous dynamic stabilization in treating adjacent segment degeneration (ASD) after lumbar spinal fusion].

OBJECTIVE: To evaluate therapeutic effects of Wallis interspinous dynamic stabilization in treating ASD after lumbar spinal fusion. METHODS: Totally 40 patients (included 16 males and 24 females, aged 25 to 60 years old) with degenerative disc disease were treated with posterior interbody fusion. Among them, 20 cases (treatment group) were treated with posterior interbody fusion combined with Wallis interspinous dynamic stabilization, while other 20 cases (control group) only treated with posterior interbody fusion. JOA score and VAS score were compared after inserted Wallis interspinous dynamic stabilization at 1 month and 3 years, and changes of intervertebral disc height of adjacent segment and cross-sectional area of the canal were tested and compared. RESULTS: All patients were followed up from 3 to 5 years with an average of 3.6 years. All injuries were healed at stage I and the pain were released after treatment. There were no significant meaning in JOA score and VAS score at 1 month after treatment between two groups (P>0.05), while had meaning at 3 years (P<0.05). There were no statistical significane in intervertebral disc height of adjacent segment and cross-sectional area of the canal at 1 month after treatment (P>0.05), while had statistical meaning at 3 years (P<0.05). CONCLUSION: There is no difference in immediate effects between two groups. Both of them can obtain good results for effective decompression. Medial-term effectiveness of treatment group is obviously better than control group, which depends on Wallis interspinous dynamic stabilization to plays good biology effects and effective accelerate adjacent degeneration caused by lumbar fusion.

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.

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.

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.

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.