Incidence of Tether Breakage in Anterior Vertebral Body Tethering.

BACKGROUND: Thoracic anterior vertebral body tethering (TAVBT) is an emerging treatment for adolescent idiopathic scoliosis. Tether breakage is a known complication of TAVBT with incompletely known incidence. We aim to define the incidence of tether breakage in patients with adolescent idiopathic scoliosis who undergo TAVBT. The incidence of tether breakage in TAVBT is hypothesized to be high and increase with time postoperatively. METHODS: All patients with right-sided, thoracic curves who underwent TAVBT with at least 2 and up to 3 years of radiographic follow-up were included. Tether breakage between 2 vertebrae was defined a priori as any increase in adjacent screw angle >5 degrees from the minimum over the follow-up period. The presence and timing of tether breakage were noted for each patient. A Kaplan-Meier survival analysis was performed to calculate expected tether breakage up to 36 months. χ 2 analysis was performed to examine the relationship between tether breakage and reoperations. Independent t test was used to compare the average final Cobb angle between cohorts. RESULTS: In total, 208 patients from 10 centers were included in our review. Radiographically identified tether breakage occurred in 75 patients (36%). The initial break occurred at or beyond 24 months in 66 patients (88%). Kaplan-Meier survival analysis estimated the cumulative rate of expected tether breakage to be 19% at 24 months, increasing to 50% at 36 months. Twenty-one patients (28%) with a radiographically identified tether breakage went on to require reoperation, with 9 patients (12%) requiring conversion to posterior spinal fusion. Patients with a radiographically identified tether breakage went on to require conversion to posterior spinal fusion more often than those patients without identified tether breakage (12% vs. 2%; P =0.004). The average major coronal curve angle at final follow-up was significantly larger for patients with radiographically identified tether breakage than for those without tether breakage (31 deg±12 deg vs. 26 deg±12 deg; P =0.002). CONCLUSIONS: The incidence of tether breakage in TAVBT is high, and it is expected to occur in 50% of patients by 36 months postoperatively. LEVEL OF EVIDENCE: Level IV.

Criminal Justice Reform Is Health Care Reform.

This Viewpoint discusses legal provisions guiding health care delivery for incarcerated individuals, the impact of the First Step Act of 2018, and future federal criminal justice reform.

Evaluating a low anion gap: A practical approach.

In teaching and in practice, little attention is given to a low anion gap. This oversight can result in a missed opportunity to diagnose acute or chronic disorders requiring treatment. In this article, we review the constituents of the anion gap, build a differential diagnosis for a low anion gap using case examples, and provide a stepwise approach to diagnostic testing to evaluate this abnormal finding.

Operative differences for posterior spinal fusion after vertebral body tethering: Are we fusing more levels in the end?

PURPOSE: Little is known about the perioperative characteristics associated with a posterior spinal fusion (PSF) in adolescent idiopathic scoliosis patients previously treated with vertebral body tethering (VBT). We aimed to determine if operative time, estimated blood loss, postoperative length of stay, instrumentation type, and implant density differed in patients that received a PSF (i.e., PSF-Only) or a PSF following a failed VBT (i.e., PSF-VBT). METHODS: We retrospectively assessed matched cohort data (PSF-VBT = 22; PSF-Only = 22) from two multi-center registries. We obtained: (1) operative time, (2) estimated blood loss, (3) postoperative length of stay, (4) instrumentation type, and (5) implant density. Theoretical fusion levels prior to the index procedure were obtained for PSF-VBT and compared to the actual levels fused. RESULTS: We observed no difference in operative time, estimated blood loss, or postoperative length of stay. Instrumentation type was all-screw in PSF-Only and varied in PSF-VBT with nearly 25% of patients exhibiting a hybrid construct. There was no added benefit to removing anterior instrumentation prior to fusion; however, implant density was higher in PSF-Only (1.9 ± 0.2) than when compared to PSF-VBT (1.7 ± 0.3). An additional two levels were fused in 50% of PSF-VBT patients, most of which were added to the distal end of the construct. CONCLUSIONS: We found that operative time, estimated blood loss, and postoperative length of stay were similar in both cohorts; however, the length of the fusion construct in PSF-VBT is likely to be two levels longer when a failed VBT is converted to a PSF.

Drain options after vertebral body tethering.

PURPOSE: Since the introduction of vertebral body tethering (VBT) for adolescent idiopathic scoliosis (AIS), a variety of post-operative chest drainage systems have been utilized. Most surgeons use formal chest tubes with a Pleur-evac, while others use smaller bulb suction drains (e.g., Blake drain). In addition, some centers utilize pleural closure. This multicenter study evaluates whether drain type or pleural closure impact perioperative and 90 day complication rates. METHODS: A retrospective review was conducted from three institutions with established VBT programs. All preoperative, perioperative and 90 day postoperative data were analyzed to determine differences in outcomes between three cohorts: standard chest tube (SCT), standard chest tube with pleural closure (SCTPC) and 10 French Bulb drain (BD). RESULTS: 104 patients were identified for the study. 57 SCT, 25 SCTPC and 22 BD. All data are listed in order: SCT, SCTPC, BD. Length of stay (3.7, 4.3, 3.0 days) was less in the BD group (p = 0.009); post-operative drainage (460, 761, 485 cc) was less in the SCT and BD groups (p < 0.001); intra-operative estimated blood loss (EBL) 146, 382, 64 cc was less in the BD group (p < 0.001). No significant difference in number of days (3.2, 3.2, and 2.8 days) drainage was in place, groups (p = 0.311). Complication profile was similar with 2 chest tube reinsertions in the SCT and one hemothorax that resolved spontaneously in BD group. CONCLUSIONS: In this series of 104 patients, SCT, SCTPC and BD all had a similar safety profile. All three methods were safe and effective in managing post-operative chest drainage after thoracic VBT. In the series, BD group had significantly shorter LOS than both groups that used chest tubes. LEVEL OF EVIDENCE: Level III, Retrospective cohort study.

Spontaneous Lumbar Curve Correction Following Vertebral Body Tethering of Main Thoracic Curves.

BACKGROUND: Growth modulation through anterior vertebral body tethering (AVBT) has emerged as a fusionless option for the treatment of progressive scoliosis. When tethering the main thoracic curve, the compensatory thoracolumbar/lumbar curve must correct indirectly as a result. The present study evaluated the response of these lumbar curves following AVBT of the main thoracic curves. METHODS: Patients who underwent thoracic AVBT and who had a minimum follow-up of 2 years were included. Magnitudes of the thoracic and lumbar curves were recorded preoperatively and at the first-erect and 2-year postoperative visits. Lumbar curves were further stratified according to their lumbar modifier (A, B, or C). Analysis of variance (ANOVA) and repeated-measures ANOVA were performed to compare correction rates, and the Pearson coefficient was utilized to determine the correlation between the tethered thoracic curve and uninstrumented lumbar curve magnitudes. RESULTS: A total of 218 patients were included. Thoracic curve correction was 40% at the first-erect visit and 43% at 2 years (p = 0.012). Lumbar correction was 30%, 26%, and 18% at the first-erect visit (p < 0.001 for all compared with preoperatively) and minimally changed at 31%, 26%, and 24% at 2 years for lumbar modifiers A, B, and C, respectively. A total of 118 patients (54%) showed thoracic curve improvement between the first-erect and 2-year visits. In a subgroup analysis, these patients had a correction in lumbar curve magnitude from preoperatively to the first-erect visit of 30%, 22%, and 16% for lumbar modifiers A, B, C, respectively, that increased to 42%, 34%, and 31% at 2 years, with strong correlation to thoracic correction at 2-year follow-up (r = 0.557, p < 0.001). CONCLUSIONS: Although there was immediate lumbar correction following AVBT of a main thoracic curve, further improvement following initial correction was only observed among patients with growth modulation of the thoracic curve. Considering all patients, the uninstrumented lumbar curve corrected 30% at 2 years and the instrumented thoracic curve corrected 40%. As indications for AVBT are refined, these data will provide insight into the response of the uninstrumented lumbar curve. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Shackling in the Hospital.

Hospitalized incarcerated patients are commonly shackled throughout their duration of treatment in community medical centers to prevent escape or harm to others. In the absence of overarching policies guiding the shackling of non-pregnant, incarcerated patients, clinicians rarely unshackle patients during routine care. We provide a medical-legal lens through which to examine inpatient shackling, review the limited evidence supporting the practice, and highlight harms associated with shackling in the hospital. We conclude by offering guidance to advance evidence-based shackling practices that prevent physical harm, reduce prejudice towards incarcerated patients, and relinquish reliance on shackles in favor of tailored security measures.