Background: Anterior spinal growth tethering (ASGT) has been shown to alter spinal growth with the potential to correct scoliosis while maintaining spine flexibility. The purpose of this study was to report the 2 to 4-year outcomes of ASGT in skeletally immature patients with thoracic scoliosis. Methods: We conducted a retrospective review of patients with thoracic scoliosis who underwent ASGT with a minimum of 2 years of follow-up. Patient demographics, perioperative data, and radiographic outcomes are reported. A “successful” clinical outcome was defined as a residual curve of <35° and no posterior spinal fusion indicated or performed at latest follow-up. Results: Seventeen patients met the inclusion criteria. The etiology was idiopathic for 14 and syndromic for 3. The mean follow-up was 2.5 years (range, 2 to 4 years). Preoperatively, all patients were at Risser stage 0, with a mean age at surgery of 11 ± 2 years (range, 9 to 14 years). There was an average of 6.8 ± 0.5 vertebrae tethered per patient. The average thoracic curve magnitude was 52° ± 10° (range, 40° to 67°) preoperatively, 31° ± 10° immediately postoperatively, 24° ± 17° at 18 months postoperatively, and 27° ± 20° at latest follow-up (51% correction; range, 5% to 118%). Revision surgery was performed in 7 patients: 4 tether removals due to complete correction or overcorrection, 1 lumbar tether added, 1 tether replaced due to breakage, and 1 revised to a posterior spinal fusion. In 3 additional patients, posterior spinal fusion was indicated due to progression. Eight (47%) of the patients had a suspected broken tether. Ten (59%) of the 17 were considered clinically successful. Conclusions: Despite most patients having some remaining skeletal growth at the time of review, the results of the current study demonstrate that at mid-term follow-up, ASGT showed a powerful, but variable, ability to modulate spinal growth and did so with little perioperative and early postoperative risk. Fusion was avoided for 13 of the 17 patients. The overall success rate was 59%, with a 41% revision rate. Understanding the parameters leading to success or failure will be critical in advancing a reliable definitive nonfusion treatment for progressive scoliosis in the future. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background: Anterior vertebral body tethering (AVBT) has been introduced as a means of correcting scoliosis without fusion. The purpose of this study was to compare outcomes for patients with thoracic idiopathic scoliosis between a group of patients who underwent AVBT and a matched cohort of patients treated with posterior spinal fusion and instrumentation (PSF). Methods: A retrospective study of patients who underwent AVBT and PSF for idiopathic scoliosis was conducted. The inclusion criteria were determined on the basis of the AVBT cohort: primary thoracic idiopathic scoliosis with a curve magnitude between 40° and 67°, Risser stage of ≤1, age of 9 to 15 years, no prior spine surgery, index surgery between 2011 and 2016, and minimum follow-up of 2 years. Demographic, radiographic, clinical, and patient-reported outcomes and revisions were compared between groups. Results: There were 23 patients in the AVBT cohort and 26 patients in the PSF cohort. The mean follow-up (and standard deviation) was similar between groups: 3.4 ± 1.1 years for the AVBT group and 3.6 ± 1.6 years for the PSF group (p = 0.6). Preoperatively, the groups were similar in all measurements of radiographic and clinical deformity, with mean main thoracic curves of 53° ± 8° for the AVBT group and 54° ± 7° for the PSF group (p = 0.4). At the time of final follow-up, the AVBT cohort had significantly more residual deformity, with a mean thoracic curve of 33° ± 18° compared with 16° ± 6° for the PSF group (p < 0.001). There were 9 revision procedures in the AVBT cohort (with 3 conversions to PSF and 3 more pending) and none in the PSF cohort. Revisions occurred at a mean postoperative time of 2.3 years (range, 1.2 to 3.7 years). Twelve patients (52%) had evidence of broken tethers; of these patients, 4 underwent revision. The post-intervention patient-reported outcomes were similar. Conclusions: Both AVBT and PSF resulted in postoperative correction; however, 2-year correction was better maintained in the PSF group. There were no differences in post-intervention patient-reported outcomes. AVBT resulted in less deformity correction and more revision procedures than PSF, but resulted in the delay or prevention of PSF in the majority of patients. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Aims: Pulmonary hypertension (PH) is characterized by an oxidant/antioxidant imbalance that promotes abnormal vascular responses. Reactive oxygen species, such as superoxide (O 2 -), contribute to the pathogenesis of PH and vascular responses, including vascular remodeling and inflammation. This study sought to investigate the protective role of a pharmacological catalytic antioxidant, a superoxide dismutase (SOD) mimetic (MnTE-2-PyP), in hypoxia-induced PH, vascular remodeling, and NALP3 (NACHT, LRR, and PYD domain-containing protein 3)-mediated inflammation. Results: Mice (C57/BL6) were exposed to hypobaric hypoxic conditions, while subcutaneous injections of MnTE-2-PyP (5 mg/kg) or phosphate-buffered saline (PBS) were given 3 · weekly for up to 35 days. SOD mimetic-treated groups demonstrated protection against increased right ventricular systolic pressure, indirect measurements of pulmonary artery pressure, and RV hypertrophy. Vascular remodeling was assessed by Ki67 staining to detect vascular cell proliferation, a-smooth muscle actin staining to analyze small vessel muscularization, and hyaluronan (HA) measurements to assess extracellular matrix modulation. Activation of the NALP3 inflammasome pathway was measured by NALP3 expression, caspase-1 activation, and interleukin 1-beta (IL-1b) and IL-18 production. Hypoxic exposure increased PH, vascular remodeling, and NALP3 inflammasome activation in PBS-treated mice, while mice treated with MnTE-2-PyP showed an attenuation in each of these endpoints. Innovation: This study is the first to demonstrate activation of the NALP3 inflammasome with cleavage of caspase-1 and release of active IL-1 b and IL-18 in chronic hypoxic PH, as well as its attenuation by the SOD mimetic, MnTE-2-PyP. Conclusion: The ability of the SOD mimetic to scavenge extracellular O 2 -supports our previous observations in EC-SOD-overexpressing mice that implicate extracellular oxidant/antioxidant imbalance in hypoxic PH and implicates its role in hypoxia-induced inflammation.

Despite a dramatic increase in the number of published articles, the research published in AJSM shifted toward more prospective, randomized, controlled, and blinded designs during 2011-2013 compared with 2001-2003 and 1991-1993, demonstrating a continued improvement in methodological quality.

Study Design. Retrospective. Objective. To evaluate the effect of preoperative rod shape on 3D spinal deformity correction. Summary of Background Data. Differential rod contouring is a surgeon-dependent process based on an estimate of 3D deformity correction sought and the flexibility of the spine. An objective measure to this otherwise subjective scoliosis correction technique is lacking. Methods. A series of adolescent idiopathic scoliosis (AIS) patients with right, thoracic major curves, preoperative rod contour tracings, and EOS imaging was evaluated. All patients underwent posterior spinal fusion with 5.5 mm steel rods contoured prior to insertion. 3D reconstructions were generated pre- and postoperatively using sterEOS software (EOS Imaging) and imported into MATLAB (Mathworks) for analysis. A new measurement of the maximum perpendicular distance from the preinsertion concave rod contour to the preoperative 3D sagittal spinal reconstruction was defined as rod to 3D spine distance (RSD). Linear regressions were used to identify relationships between pre and postoperative parameters, including RSD and 3D thoracic kyphosis. Results. Ninety-nine patients were included. Average preoperative concave rod angle decreased from (48 ± 10°) preoperatively to 26 ± 6° postoperatively (P < 0.001) for an average flattening of ∼20°. Average convex rod angle increased from 30 ± 6° to 34 ± 5° (P < 0.001). Average preoperative thoracic curve magnitude and apical vertebral rotation were 57 ± 8° and 16 ± 5° and decreased to 11 ± 6° and 5 ± 6° (P < 0.001). Average 2D and 3D thoracic kyphosis increased from 19 ± 14° and 2 ± 12° to 27 ± 6° and 22 ± 5° (P < 0.001). Preoperative RSD strongly correlated with 3D thoracic kyphosis change (P < 0.001, r = 0.796, R 2 = 0.633). Conclusion. On average, the concave rod flattened ∼20° after connection to the spine. Similarly, kyphosis increased ∼20° following rod insertion. A strong correlation was identified between RSD and 3D thoracic kyphosis restoration. This novel 3D parameter can guide the degree of concave rod bend necessary to achieve a desired increase in thoracic kyphosis in AIS. Level of Evidence: 2