Long-term adjacent segment degeneration at average 21-year follow-up of posterior instrumented fusion for adolescent idiopathic scoliosis.

INTRODUCTION: Posterior instrumented fusion for progressive adolescent idiopathic scoliosis (AIS) is generally considered to have good outcomes, but very long-term reviews are rare. Data on adjacent segment degeneration (ASD) following posterior instrumented thoracic fusion for AIS are lacking. The primary aim was to assess the incidence of ASD and to correlate this with radiographic measures and patient-reported outcome measures (PROMs). The secondary aim was to assess maintenance of curve correction at very long-term follow-up. METHODS: This single-surgeon consecutive case series of 47 AIS patients was identified from a prospectively collated dataset. As the primary outcome, ASD was assessed radiographically using the Mimura grading system. Pulmonary function tests and PROMs were assessed along with secondary radiographic outcome measures. RESULTS: Radiographic follow-up was achieved in 77% (36/47) of patients at an average of 21 years (range, 16.5-26.5 years) after surgery. Radiographic evidence of ASD was seen in 64%. PROMs showed a mean Oswestry disability index of 12.1% with an overall Scoliosis Research Society 22 score averaging at 3.7 out of 5. The Coronal Cobb Angle was corrected from an average of 57° preoperatively to 19° immediately postoperatively, deteriorating to 22° at final review, maintaining a 61% curve correction. CONCLUSIONS: Radiographic evidence of ASD was found in 64% of the cohort. The patient-reported outcome measures were good, with few limitations to activities.

Partial Intervertebral Fusion Secures Successful Outcomes After Thoracoscopic Anterior Scoliosis Correction: A Low-Dose Computed Tomography Study.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVES: To analyze intervertebral (IV) fusion after thoracoscopic anterior spinal fusion (TASF) and explore the relationship between fusion scores and key clinical variables. SUMMARY OF BACKGROUND INFORMATION: TASF provides comparable correction with some advantages over posterior approaches but reported mechanical complications, and their relationship to non-union and graft material is unclear. Similarly, the optimal combination of graft type and implant stiffness for effecting successful radiologic union remains undetermined. METHODS: A subset of patients from a large single-center series who had TASF for progressive scoliosis underwent low-dose computed tomographic scans 2 years after surgery. The IV fusion mass in the disc space was assessed using the 4-point Sucato scale, where 1 indicates <50% and 4 indicates 100% bony fusion of the disc space. The effects of rod diameter, rod material, graft type, fusion level, and mechanical complications on fusion scores were assessed. RESULTS: Forty-three patients with right thoracic major curves (mean age 14.9 years) participated in the study. Mean fusion scores for patient subgroups ranged from 1.0 (IV levels with rod fractures) to 2.2 (4.5-mm rod with allograft), with scores tending to decrease with increasing rod size and stiffness. Graft type (autograft vs. allograft) did not affect fusion scores. Fusion scores were highest in the middle levels of the rod construct (mean 2.52), dropping off by 20% to 30% toward the upper and lower extremities of the rod. IV levels where a rod fractured had lower overall mean fusion scores compared to levels without a fracture. Mean total Scoliosis Research Society (SRS) questionnaire scores were 98.9 from a possible total of 120, indicating a good level of patient satisfaction. CONCLUSIONS: Results suggest that 100% radiologic fusion of the entire disc space is not necessary for successful clinical outcomes following thoracoscopic anterior selective thoracic fusion.

Vascularized fibula strut graft used in neurofibromatosis type 1-related kyphosis: a case of almost complete reversal of deformity-induced tetraparesis.

Study Design Case report. Objective The aim of this study is to describe a case of vascularized fibula strut graft implanted in the cervicothoracic spine of a patient with neurofibromatosis type 1-related progressive kyphosis. Methods A detailed history examination of the surgical procedures and the results of the follow-up after fibula strut graft implantation were performed. In addition, a review of the literature was conducted to access the incidence of similar cases with an almost complete reversal of a deformity-induced tetraparesis. Results A 37-year-old man with severe type 1 neurofibromatosis causing a collapsing kyphosis of the cervicothoracic spine presented in 2006 with progressive low cervical tetraparesis. Intervention included posterior stabilization (C5 to T5) which was extended to C3-T9 in 2008; however, the kyphosis continued to worsen. In 2009, a vascularized fibula strut graft was implanted between the inferior and superior endplates of C3 and T9. Over the following months, the patient gradually recovered motor strength and improved functional use of all limbs. In March 2011, lower limb (bilateral) and right arm strength was grade 5, with left arm strength being grade 4+. Conclusions This case report demonstrates the existence of a potential local option for the difficult problems of pseudoarthrosis, progressive spinal deformity, and cord compromise in patients with neurofibromatosis type 1-related kyphosis resulting in an almost complete reversal of deformity-induced tetraparesis.