Satisfactory restoration of thoracic kyphosis in Lenke I AIS curves using bilateral vertebral coplanar alignment: an international multicenter experience.

STUDY DESIGN: Review of a prospective multicenter registry. OBJECTIVE: To report the correction of the thoracic sagittal profile in Lenke 1 curves using the bilateral vertebral coplanar alignment (BVCA) maneuver. All-pedicle-screw construtcs provide satisfactory coronal correction but fail to accurately restore the frequent thoracic hypokyphosis of Lenke 1 curves. BVCA is a recently described technique focused on restoration of the normal thoracic kyphosis alignment in AIS patients. METHODS: A non-consecutive series of 49 AIS patients underwent surgical correction of the deformity by only posterior pedicle screw construct. Coronal and sagittal curve correction was assessed by conventional standing X-rays at preoperative and 2-year follow-up visits. BVCA reduction maneuvers include the correction of the deformity, while descending an implantable rod within slotted tubes attached to the convex side screws. Restoration of physiologic kyphosis is achieved by spreading the distal ends of the tubes at the thoracic spine using different-sized spacers. RESULTS: Mean preoperative Cobb of the MT curves was 58.4° and was corrected at 70.9%. Preoperative apical vertebral rotation was 18.6° on average and was corrected at 52.9%. T5-T12 kyphosis showed a significant improvement from a mean angle of 18.8º (95% CI 13.3-24.8) to 23.5º (95% CI 20.1-26.1) at 2-year follow-up (a 25% increase) (p = 0.040). Patients with (-) sagittal modifier gained 13.9º on average; those with ( +) modifier decreased 24.0°, and patients with N sagittal modifier remained almost unchanged (2.9°). Differences in the changes of the thoracic sagittal profile between the three groups were statistically significant (p < 0.001). After surgical correction of scoliosis, 87.8% of the patients were considered normokyphotic. CONCLUSIONS: Clinical results have proven the ability of BVCA to obtain good correction of the deformity in the coronal plane, similar to other methods. However, this technique permits a more relevant restoration of thoracic kyphosis.

Adjacent segment degeneration and revision surgery after circumferential lumbar fusion: outcomes throughout 15 years of follow-up.

PURPOSE: This retrospective study analyzes long-term outcomes (15 years) of circumferential lumbar fusion (CF) for degenerative spine disease using instrumented PLIF. The occurrence of adjacent segment degeneration (ASD) and the reintervention rate was specially focused. METHODS: A series of 73 patients who underwent CF (1-3 levels) was reviewed. Patients were evaluated preoperatively, at 2, 5, 10 and 15 years after surgery with static and dynamic radiographic studies, CT scan and MRI. Patients completed also the Oswestry-Disability index (ODI), the VAS score, and the patient self-satisfaction questionnaire. RESULTS: At 2-year follow-up, there was a decrease in the average ODI score (from 72.3 ± 16.4 preop to 30.5 ± 6.2). At 10- and 15-year follow-up, ODI scores return to preoperative scores in patients without revision surgery. The 82.8 % of patients referred an excellentgood self-satisfaction rate at this time. At 5-year follow-up, seven patients (9.6 %) required reoperation because of symptomatic ASD. At 10-year follow-up, reoperated patients increased to 24.6 % (18 cases). Excellent and good self-satisfaction rate decreased to 41.1 % at this time. Radiological ASD was then detected in 37 cases (50.7 %). At 15-year follow-up, nine patients were lost and a total of 24 (37.5 %) required a new surgical treatment because of ASD. The occurrence of revision surgery because of symptomatic ASD was highly dependent of the age of patients at the first surgery and the number of fused levels. CONCLUSION: Circumferential lumbar fusion provides good clinical results at short-term follow-up. From 2- to 15-year follow-up, outcome worsened significantly. The high rate of ASD occurrence and reintervention questions the reliability of this technique for lumbar fusion.

Cervical and thoracic sagittal misalignment after surgery for adolescent idiopathic scoliosis: a comparative study of all pedicle screws versus hybrid instrumentation.

STUDY DESIGN: A comparative study of 2 cohort series of surgically treated patients with adolescent idiopathic scoliosis (AIS) who were retrospectively analyzed, with level III evidence. OBJECTIVE: To compare the effect on the cervical sagittal balance of 2 AIS correction constructs, namely, all pedicle screws and hybrid instrumentation using hooks and pedicle screws. SUMMARY OF BACKGROUND DATA: An inverse relationship between cervical and thoracic kyphosis in AIS has been found in pediatric patients after concave derotation using hybrid constructs with pedicle screws and hooks. METHODS: Two series of 25 nonconsecutive patients with Lenke type-I AIS who underwent spinal fusion were retrospectively reviewed. In 1 series, the patients were treated with all thoracic pedicle screw constructs. In the other series, the correction was achieved by using hybrid constructs. Preoperative and 2-year follow-up radiographical examinations were evaluated, measuring the following parameters: C2-C7 sagittal angle, displacement of C2-C7 plumb line, T1 sagittal tilt, T1-T5 and T5-T12 sagittal profile, and C7-S1 global sagittal balance. RESULTS: In both groups, there was a lordotic effect on the T5-T12 kyphosis after surgery, with an average loss of 6.1° for hybrid and 7.7° for pedicle screws. When the postoperative data were compared, the intergroup differences were found only in the sagittal C2-C7 Cobb angle, showing a mean kyphotic trend (-5.2°) in the pedicle screws group compared with a mean lordotic trend (1.8°) in the hybrid group (P < 0.05). In both techniques, the patients with upper-instrumented vertebra at T4 or below showed a lordotic effect that was more evident in the hybrid constructs (+9.4° ± 11.3 vs. +0.3° ± 11.4). In those with the upper-instrumented vertebra at T3 or higher levels, both techniques had a kyphotic effect that was more severe in the patients of the pedicle screws group (-7.0° ± 12.6 vs. -2.8° ± 10.5). CONCLUSION: Independent of the surgical technique used, the cervical spine had a tendency to decompensate and acquire a kyphotic sagittal profile. Constructs based on all pedicle screws have a stronger hypokyphotic effect on the thoracic spine, with a predisposition to greater decompensation of the cervical spine. Kyphotic changes in the C2-C7 sagittal alignment induced by scoliosis correction are correlated with the level of the upper-instrumented vertebra.