Kapurch, Joseph R

OBJECTIVE The objective of this study was to understand the natural history of scoliosis in patients with Chiari malformation type I (CM-I) with and without syringomyelia. METHODS A retrospective review of data was conducted. Patients with CM-I were identified from a cohort of 14,118 individuals age 18 years or younger who had undergone MRI over an 11-year period at the University of Michigan. Patients eligible for study inclusion had a coronal curve ≥ 10° on radiography, associated CM-I with or without syringomyelia, and at least 1 year of clinical follow-up prior to any surgery. Curve magnitude at initial diagnosis, prior to posterior fossa decompression (PFD; if applicable), and at the last follow-up (prior to any surgical correction of scoliosis) was recorded, and clinical and radiographic characteristics were noted. The change in curve magnitude by 10° was defined as curve progression (increase by 10°) or regression (decrease by 10°). RESULTS Forty-three patients met the study inclusion criteria and were analyzed. About one-third (35%) of the patients presented with symptoms attributed to their CM-I. The mean degree of scoliosis at presentation was 32.6° ± 17.7°. Twenty-one patients (49%) had an associated syrinx. The mean tonsil position below the level of the foramen magnum was 9.8 ± 5.8 mm. Patients with a syrinx were more likely to have a curve > 20° (86% vs 41%, p = 0.002). Curve magnitude remained stable (≤ ±10°) in 77% of patients (33/43), progressed in 16% (7/43), and regressed in 7% (3/43). Mean age was higher (14.8 ± 0.59 years) among patients with regressed curves (p = 0.026). All regressed curves initially measured ≤ 20° (mean 14° ± 5.3°), and none of the patients with regressed curves had a syrinx. The change in curve magnitude was statistically similar in patients with (7.32° ± 17.7°) and without (5.32° ± 15.8°) a syrinx (p = 0.67). After a mean follow-up of 3.13 ± 2.04 years prior to surgery, 27 patients (63%) ultimately underwent posterior fossa or scoliosis correction surgery. For those who eventually underwent PFD only, the rate of change in curve magnitude prior to surgery was 0.054° ± 0.79°. The rate of change in curve magnitude was statistically similar before (0.054° ± 0.79°) and after (0.042° ± 0.33°) surgery (p = 0.45) for patients who underwent PFD surgery only. CONCLUSIONS The natural history of scoliosis in the presence of CM-I is variable, though most curves remained stable. All curves that regressed were ≤ 20° at initial diagnosis, and most patients in such cases were older at scoliosis diagnosis. Patients who underwent no surgery or PFD only had similar profiles for the change in curve magnitude, which remained relatively stable overall, as compared to patients who underwent PFD and subsequent fusion, who demonstrated curve progression. Among the patients with a syrinx, no curves regressed, most remained stable, and some progressed. Understanding this variability is a first step toward building a prediction model for outcomes for these patients.

Objective: To determine whether operating on “major” vertebral fractures leads to premature abortion of surgery and/or other acute cardiopulmonary complications. Design: Retrospective review. Clinical Setting: Level 1 trauma center. Patients/Participants and Intervention: We retrospectively queried our institutional Trauma Rregistry for all cases presenting with concomitant rib fractures and surgically managed vertebral fractures. Main Outcome Measurements: The main outcomes included the surgical outcome (aborted vs. successfully performed), total and Intensive Care Unit length of stay (LOS), adverse discharge, mortality, and functional outcomes. Results: We found 57 cases with concomitant segmental rib fractures and surgically managed vertebral fractures. Seven patients (12%) received a rib fixation, of which 1 received before vertebral fixation and 6 after. Importantly, 4 vertebral fixation cases (7.02%) had to be aborted intraoperatively because of the inability to tolerate prone positioning for surgery. For case–control analysis, we performed propensity score matching to obtain matched controls, that is, cases of vertebral fixation but no rib fractures. On matched case–control analysis, patients with concomitant segmental rib fractures and vertebral fractures were found to have higher Intensive Care Unit LOS [median = 3 days (Inter-Quartile Range = 0–9) versus. 8.4 days, P = 0.003], whereas total LOS, frequency of complete, incomplete or functional spinal cord injury, discharge to rehab, and discharge to nursing home were found to be similar between the 2 groups. Conclusion: Our findings demonstrate that segmental rib fractures with concomitant vertebral fractures undergoing surgical treatment represent a subset of patients that may be at increased risk of intraoperative cardio-pulmonary complications and rib fixation before prone spine surgery for cases in which the neurological status is stable is reasonable. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.