Comparison of surgical treatment in Lenke 5C adolescent idiopathic scoliosis: anterior dual rod versus posterior pedicle fixation surgery: a comparison of two practices.

Department of Orthopaedics, Spine Austin, 3001 Beecaves Road, Austin, TX 78746, USA.
Spine (Impact Factor: 2.16). 09/2009; 34(18):1942-51. DOI: 10.1097/BRS.0b013e3181a3c777
Source: PubMed

ABSTRACT Multicenter analysis of 2 groups of patients surgically treated for Lenke 5C adolescent idiopathic scoliosis (AIS).
Compare patients with Lenke 5C scoliosis surgically treated with anterior spinal fusion with dual rod instrumentation and anterior column support with patients surgically treated with posterior release and pedicle screw instrumentation.
Treatment of single, structural, lumbar, and thoracolumbar curves in patients with AIS has been the subject of some debate. Advocates of the anterior approach assert that their technique spares posterior musculature and may save distal fusion levels, and that with dual rods and anterior column support the issues with nonunion and kyphosis have been obviated. Advocates of the posterior approach assert that with the change to posterior pedicle screw based instrumentation that correction and levels are equivalent, and the posterior approach avoids the issues with nonunion and kyphosis. This report directly compares the results of posterior versus anterior instrumented fusions in the operative treatment of adolescent idiopathic Lenke 5C curves.
We analyzed 62 patients with Lenke 5C based on radiographic and clinical data at 2 institutions: 31 patients treated with posterior, pedicle-screw instrumented fusions at 1 institution (group PSF); and 31 patients with anterior, dual-rod instrumented fusions at another institution (group ASF). Multiple clinical and radiographic parameters were evaluated and compared.
The mean age, preoperative major curve magnitude, and preoperative lowest instrumented vertebral (LIV) tilt were similar in both groups (age: PSF = 15.5 years, ASF = 15.6 years; curve size: PSF = 50.3 degrees +/- 7.0 degrees , ASF = 49.0 degrees +/- 6.6 degrees ; LIV tilt: PSF = 27.5 degrees +/- 6.5 degrees , ASF = 27.8 degrees +/- 6.2 degrees ). After surgery, the major curve corrected to an average of 6.3 degrees +/- 3.2 degrees (87.6% +/- 5.8%) in the PSF group, compared with 12.1 degrees +/- 7.4 degrees (75.7% +/- 14.8%) in the ASF group (P < 0.01). At final follow-up, the major curve measured 8.0 degrees +/- 3.0 degrees (84.2% +/- 5.8% correction) in the PSF group, compared with 15.9 degrees +/- 9.0 degrees (66.6% +/- 17.9%) in the ASF group (P = 0.01). This represented a loss of correction of 1.7 degrees +/- 1.9 degrees (3.4% +/- 3.7%) in the PSF group, and 3.8 degrees +/- 4.2 degrees (9.4% +/- 10.7%) in the ASF group (P = 0.028). The LIV tilt decreased to 4.1 degrees +/- 3.4 degrees after surgery in the PSF group, and 4.5 degrees +/- 3.7 degrees in the ASF group. At final follow-up, the LIV tilt was 5.1 degrees +/- 3.5 degrees in the PSF group, and 4.5 degrees +/- 3.7 degrees in the ASF group. EBL was identical in both groups, and length of hospital stay was significantly (P < 0.01) shorter in the PSF group (4.8 vs. 6.1 days). There were no complications in either group which extended hospital stay or required an unplanned second surgery.
At a minimum of 2-year follow-up, adolescents with Lenke 5C curves demonstrated statistically significantly better curve correction, less loss of correction over time, and shorter hospital stays when treated with a posterior release with pedicle screw instrumented fusion compared with an anterior instrumented fusion with dual rods for similar patient populations.

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    ABSTRACT: BACKGROUND: The pelvis as the biomechanical foundation of spine, plays an important role in the balance of the stance and gait through the multi-link spinal-pelvic system. If the pelvic axial rotation (PAR) exists in adolescent idiopathic scoliosis (AIS) patients, it should theoretically have some effects on the body balance. PURPOSE: To explore the probable effects of preoperative PAR on the spinal balance in coronal plane in AIS patients with main thoracolumbar/lumbar (TL/L) curve after posterior spinal instrumentation. METHODS: Thirty-eight AIS patients (age: 15 ± 1.5 years) with main TL/L curve (51° ± 6.2°) were recruited retrospectively into this study. The mean follow-up period was 27 months (24-36 months). Standing full spine posteroanterior radiographs were taken preoperatively, 3 month and 1 year postoperatively, and at last follow-up. The convex/concave ratio (CV/CC ratio) of the anterior superior iliac spine laterally and the inferior ilium at the sacroiliac joint medially was measured on posteroanterior radiographs. According to the preoperative CV/CC ratios, the patients were divided into two groups: normal group (N-group: 0.95 ≤ CV/CC ≤ 1.05); and the asymmetrical group (A-group: CV/CC < 0.95, or >1.05). RESULTS: In all the patients, the 3-month-postoperative CV/CC ratio (1.026 ± 0.087) was significantly different from the preoperative CV/CC ratio (0.969 ± 0.095, P < 0.001), indicating that the pelvis had rotated in the opposite direction of the corrective derotation load applied to the TL/L spine after surgery. No significant change was found in the CV/CC ratio from 3-month-postoperative to the last follow-up (1.013 ± 0.103, P > 0.05). There was no significant difference in the demographic, phenotypic, and treatment variables between the N- (n = 16) and A-groups (n = 22) (P > 0.05). However, more coronal decompensation occurred in the A-group after surgery (36.4 vs. 0.0 %, P = 0.013): two patients having trunk translation, three having lower instrumented vertebra (LIV) translation, and one having LIV tilt; meanwhile, one patient having both LIV translation and LIV tilt, and one having both trunk translation and LIV tilt. CONCLUSIONS: The present study confirmed the existence of PAR in AIS patients, and indicated that the pelvis would experience an active rebalancing in the transverse plane within 3 months after spinal correction, and since then, its position would remain stable. Moreover, TL/L-AIS patients with preoperative asymmetrical PAR probably had greater risk of coronal decompensation postoperatively.
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    ABSTRACT: Anterior open scoliosis surgery using the dual rod system is a safe and rather effective procedure for the correction of scoliosis (50–60 %). Thoracic hypokyphosis and rib hump correction with open anterior rather than posterior instrumentation appear to be the better approaches, although the latter is somewhat controversial with current posterior vertebral column derotation devices. In patients with Risser grade 0, hyperkyphosis and adding-on may occur with anterior thoracic spine instrumentation. Anterior thoracoscopic instrumentation provides a similar correction (65 %) with good cosmetic outcomes, but it is associated with a rather high risk of instrumentation (pull-out, pseudoarthrosis) and pulmonary complications. Approximately 80 % of patients with adolescent idiopathic scoliosis (AIS) curves of >70° have restrictive lung disease or smaller than normal lung volumes. AIS patients undergoing anterior thoracotomy or anteroposterior surgery will demonstrate a significant decrease in percentage of predicted lung volumes during follow-up. The thoracoabdominal approach and thoracoscopic approach without thoracoplasty do not produce similar changes in detrimental lung volume. In patients with severe AIS (>90°), posterior-only surgery with TPS provides similar radiographic correction of the deformity (44 %) with better pulmonary function outcomes than anteroposterior surgery. Vascular spinal cord malfunction after segmental vessel ligation during anterior scoliosis surgery has been reported. Based on the current literature, the main indication for open anterior scoliosis instrumentation is Lenke 5C thoracolumbar or lumbar AIS curve with anterior instrumentation typically between T11 and L3.
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