Assessment of rib hump deformity correction in adolescent idiopathic scoliosis with or without costoplasty using the double rib contour sign.

STUDY DESIGN: Level III-therapeutic study. OBJECTIVE: The purpose of this study was to determine whether the addition of costoplasty in adolescent idiopathic scoliosis surgery improved correction of the rib hump deformity. BACKGROUND: Trunk deformity is comprised of vertebral rotation, posterior vertebral element, and rib deformities. Surgical correction of the rotational deformity has been performed by segmental spinal instrumentation with vertebral derotation, but complete correction of the rib hump by derotation is rarely achieved. METHODS: A multicenter registry database for adolescent idiopathic scoliosis was reviewed with the inclusion criteria of Lenke type I curves treated with posterior spinal fusion with or without costoplasty, instrumented with pedicle screws or hybrid constructs, with a minimum follow-up of 2 years. The first group (group I) was treated with pedicle screws, direct vertebral rotation, and no costoplasty, whereas the second group (group II) was treated with pedicle screws, vertebral rotation, and costoplasty. The rib index (RI), calculated from the double rib contour sign, and Cobb angle were measured radiographically and compared between groups. RESULTS: The groups comprised 36 subjects in group I and 40 subjects in group II. The mean preoperative Cobb angles for groups I and II were 49.7 and 49.8 degrees, respectively, whereas the mean postoperative Cobb angles were 10.2 and 10.9 degrees, respectively. There was no difference in preoperative and postoperative values when comparing both groups (P=0.48 and 0.96, respectively). Before spine surgery, RI for groups I and II was 1.61 and 1.80, respectively. Postoperatively, the rib indices were 1.39 for group I and 1.29 for group II. These differences were found to be statistically significant (P=0.002 and 0.006, respectively). The amounts of correction of RI were 0.23 and 0.51 for groups I and II, respectively. This difference was found to be statistically significant (P<0.0001). The correction percentages were 13.7% and 28.3%, respectively. This difference was also found to be statistically significant (P<0.0001). CONCLUSIONS: Costoplasty combined with pedicle screws and vertebral derotation may significantly improve rib hump deformity as opposed to pedicle screws and vertebral derotation alone.

Interpretation of skeletal variations for human risk assessment: delayed ossification and wavy ribs.

Delayed (or incomplete) ossification of developing fetal bones and wavy ribs are some of the most common skeletal variations encountered in regulatory guideline developmental toxicity studies. Although they tend to be regarded as minor effects, they can be quite sensitive and consequently may influence the study lowest-observed-adverse-effect levels (LOAELs), and thus, impact classification, labeling, and risk assessment. In this study, we review the underlying mechanisms of these skeletal variations, evaluate different scenarios in which they have been observed, offer guidance for their interpretation, and comment on their use for risk assessment. Both minor delays in ossification and wavy ribs seem to be readily repairable via postnatal skeletal remodeling, are not mechanistically linked to malformation, and often are seen in the presence of maternal or fetal toxicity. As such, these minor variations would not generally be considered adverse in and of themselves but should be interpreted in the context of other maternal and fetal findings, information available on normal skeletogenesis patterns, mode of action of the test agent, and historical control incidence using a weight of evidence approach.

Pulmonary function assessment in an infant with Barnes syndrome: proactive evaluation for surgical intervention.

Our aim for this study was to report pulmonary mechanics in a neonate with a severe case of Barnes syndrome, a rare form of thoracolaryngopelvic dysplasia, and to use these data to guide ventilatory support and serve as a presurgical screening tool. A comprehensive pulmonary function evaluation was performed on a 36-day-old patient with Barnes syndrome who was being mechanically ventilated because of severe pulmonary distress secondary to thoracic dystrophy. The measurements consisted of respiratory volumes including functional residual capacity, ventilatory mechanics including compliance and resistance, and thoracoabdominal synchrony. Chest wall compliance was 64% below normal, and the thoracoabdominal motion was indicative of predominantly abdominal displacement during inspiratory breaths. The lungs were functioning at a low functional residual capacity, resulting in low lung compliance and increased pulmonary resistance. As a result of the evaluation, the patient was recommended for lateral thoracic expansion surgery and the ventilatory management was adjusted to focus on end-distending pressure support.

Teratological assessment of diiodomethyl p-tolyl sulfone in rats.

Pregnant rats were given diiodomethyl p-tolyl sulfone (DIMPTS) at a dose of 0, 0.125, 0.25, 0.5 or 1.0% in the diet on days 6-15 of pregnancy. Maternal body weight gain and food consumption during the administration period were significantly lowered in the 0.25, 0.5 and 1.0% groups. No significant changes induced by DIMPTS were detected in the number of resorptions and dead fetuses, and body weight of live fetuses. Morphological examinations of fetuses revealed no evidence of teratogenesis. It could be concluded that DIMPTS has no teratogenic effects on rat offspring, even at doses which induced maternal toxicity.