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Vertebral body tethering (VBT) has been reported as a safe and effective non-fusion surgical technique for the treatment of adolescent idiopathic scoliosis, but the postoperative health of the bone and soft tissues of the spine following instrumentation remains unknown. We aimed to evaluate pathoanatomy and degenerative changes of the spine in adolescent idiopathic scoliosis patients both prior to and two years following VBT. We prospectively enrolled nine patients who underwent VBT for the treatment of progressive adolescent idiopathic scoliosis. All patients received preoperative and two-year postoperative magnetic resonance imaging of their spine; images were assessed for pathoanatomy (e.g. nucleus pulposus positioning and muscle atrophy) and degenerative changes (e.g. Schmorl nodes, endplate oedema, disc degeneration, and osteoarthritis) at each vertebral level between T1 and S1. Four patients (44%) exhibited a shift of the nucleus pulposus from an eccentric position at baseline towards midline at three or more levels, most of which were in the tethered region. Tethering did not affect preexisting fatty atrophy of multifidus. No patients exhibited postoperative Schmorl nodes, endplate oedema, or disc degeneration in either the tethered or untethered regions. Four patients (44%) presented with mild facet osteoarthritis in the lower lumbar spine, which did not change postoperatively. One patient developed moderate facet osteoarthritis at L5-S1. These preliminary data indicate that VBT may not result in significant degenerative changes in either the intervertebral discs or the posterior facets two years following instrumentation.

BACKGROUND: Multiple systems using radiographic skeletal markers to measure development have been described, including the Greulich and Pyle Atlas (GP), the Fels Method (Fels), and the Sanders Hand Classification (Sanders). The purpose of this study was to quantitatively assess whether the integration of skeletal maturity assessment methods and demographic variables improves the accuracy of pediatric growth predictions over the use of skeletal markers or chronologic age alone. METHODS: The Brush Inquiry contains prospectively collected longitudinal data on children who lived in Cleveland, Ohio between 1926 and 1942. A total of 16 boys and 29 girls were selected for study. All had age, height, and an anteroposterior radiograph of the hand at each of 3 visits. Those visits occurred at 85%, 90%, and 95% of final height. We determined the growth completed at each visit by dividing the height observed by the final height at skeletal maturity. Boys and girls were analyzed separately using chronologic age, height, GP, Fels, and Sanders. The residual difference between the height predicted and actual height, as well as the SD of the prediction error of the cohort at each time point was calculated. To account for multiple visits from each subject, all linear models were produced using the generalized estimating equations (GEEs) procedure. RESULTS: For boys, age, GP, and Fels performed similarly in predicting growth remaining at all 3 time points. For girls, age, GP, and Fels performed similarly in predicting growth remaining at the 85% and 95% time points; however, the Fels Method demonstrated improved performance at the 90% time point compared with chronologic age (P = 0.0076) and GP alone (P = 0.0155). For both boys and girls, the most accurate multivariate GEE model with the lowest SD of prediction error integrated Fels, age, GP, Sanders, and height. CONCLUSIONS: The most accurate multivariate GEE model of growth prediction for both boys and girls integrated Fels, age, GP, Sanders, and height. When calculating the amount of growth remaining, it is prudent to integrate multiple systems for greater predictive accuracy. LEVEL OF EVIDENCE: Level III.

Background Anterior vertebral body tethering (VBT) is an early treatment option for progressive scoliosis in pediatric patients, allowing for continued deformity correction during normal growth. We report postoperative radiographic and clinical outcomes for patients treated with VBT. Methods This clinical and radiographic retrospective review of 31 consecutive patients included an analysis of preoperative, perioperative, and postoperative details, including the Lenke classification; Cobb angle measurements of the proximal thoracic, main thoracic, and lumbar curves; the sagittal profile; and skeletal maturity. Successful outcomes were defined by a residual curve of ≤30° in skeletally mature patients who did not undergo a posterior spinal fusion (PSF). Results Of the 31 patients treated, 29 met the inclusion criteria, and 2 were lost to follow-up. The mean patient age (and standard deviation) at the time of the surgical procedure was 12.7 ± 1.5 years (range, 10.2 to 16.7 years), with most patients classified as Risser grade 0 or 1 (52%) and Sanders stage 3 (32%). A mean of 7.2 ± 1.4 vertebral levels were instrumented, with a minimum preoperative Cobb angle of 42°. At the latest follow-up, 27 patients had reached skeletal maturity (Sanders stage ≥7) and 20 patients exhibited a curve magnitude ≤30°, for a success rate of 74%. A suspected broken tether occurred at ≥1 level in 14 patients (48%). Two patients underwent PSF and 4 had tether revision. The overall revision rate was 21% (6 of 29). Conclusions This study shows the success and revision rates as well as the impact of a suspected broken tether on the procedural success of VBT. Despite our patient population being slightly more mature at the time of the surgical procedure compared with previous studies, we had a higher success rate and a lower revision rate. A PSF was avoided in 93% of patients, indicating that VBT may be a reliable treatment option for adolescent scoliosis in skeletally immature individuals. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND: Epiphyseal fusion (EF) marks the completion of longitudinal bone growth, a critical milestone monitored during treatment of skeletal growth and/or developmental disorders. Recently, a trend toward accelerated skeletal maturation in children has been documented. Because current methods for assessing skeletal maturation include children in their reference populations born as early as the 1930s, the timing of EF events in contemporary patients may differ substantially from those standards. QUESTIONS/PURPOSES: (1) Do children today initiate the process of EF in the hand and wrist earlier than past generations on which maturity standards are based? (2) Do children today complete EF in the hand and wrist earlier than past generations on which maturity standards are based? METHODS: A total of 1292 children (665 males, 627 females) participating in the Fels Longitudinal Study, born between 1915 and 2006, were included in this retrospective, observational study. Each participant had between one and 39 serial left hand-wrist radiographs during childhood obtained specifically for research purposes. Main outcomes were the chronological age at the first sign of EF initiation (EF-I) and the first chronological age when EF was complete (EF-C) in the radius and ulna, and metacarpals and phalanges of the first, third, and fifth rays according to criteria of the Fels method. EF is a reliable metric with an average κ agreement statistic of 0.91. Penalized B-splines were used to model the changes in EF-I and EF-C ages and to identify changes across continuous birth years with major comparisons between children born in 1935 and 1995. RESULTS: Approximately half of the epiphyses of the hand and wrist examined exhibited earlier EF-I and/or earlier EF-C in children born in 1995 compared with those born in 1935. The age at each milestone (EF-I and EF-C) decreased by as much as 6.7 and 6.8 months in males and 9.8 and 9.7 months in females, respectively. This change occurred gradually over the past century. The more proximal traits (EF of the distal radius, distal ulna, and metacarpals) were more likely to experience a shift in timing, whereas timing of EF in the phalanges remained relatively stable across birth years. CONCLUSIONS: A trend has occurred over the past century in the timing of EF, in both initiation and completion of the process, for many of the bones of the hand and wrist. Earlier EF reflects modern population advances in both skeletal and sexual maturation. Shifts in the timing of EF have the potential to influence treatment strategies for skeletal growth and/or developmental disorders such as scoliosis or leg length inequality, moving treatment windows to earlier ages. Earlier EF-I and EF-C identified in this study signals a need to reevaluate the timing of maturational milestones and current standards for skeletal assessment. LEVEL OF EVIDENCE: Level II, prognostic study.