1287 Clinical and Radiographic Markers of the Natural History of Achondroplasia: A Multi-Site Cohort Analysis

INTRODUCTION: Among skeletal dysplasias, achondroplasia is the most common, occurring with a prevalence of 1 in every 20000 births. The condition stems from an FGFR3 dysfunction and frequently results in diverse skeletal and neurological symptoms with patient development. While the natural history has been previously explored, additional large-scale studies are needed to better understand the needs of these patients, including the need for neurosurgical decompression or spine fusion. METHODS: A multi-site cohort analysis of patients seen for achondroplasia between 2006 and 2023 was conducted at 5 large academic hospitals. All patients had initial and follow up clinic visits with a neurologist or neurosurgeon. Demographic data, presenting symptoms, imaging characteristics, and surgical outcomes were collected. Data over the length of follow-up were compared using SPSS. RESULTS: 150 patients were identified (48% were female; mean age was 1.2 ± 2.4 years; average follow-up period of 7.3 ± 5.8 years). Hearing deficits (n=25, 17%), middle ear disease (n=21, 14%), and pain (n=17, 11%) were the most common presenting symptoms. In those with imaging follow-up, the most frequent radiographic findings were foramen magnum stenosis (n=76, 100%), spinal stenosis (n=40, 53%), scoliosis (n=40, 53%), and macrocephaly (n=35, 46%). Incidentally, twenty-six (34%) patients had ventriculomegaly. Fifty-four patients required surgery (mean age at initial surgery was 3.9 ± 4.7 years; average of 1.2 cranial and 1.6 spinal surgeries performed). The most common cranial and spinal procedures were suboccipital craniectomy for foramen magnum decompression and lumbar laminectomy for spinal stenosis, respectively. CONCLUSIONS: In this large, multi-center study of this rare congenital syndrome, multiple neurosurgical interventions were often required. Close clinical follow-up care in a neurosurgical and spine clinic would likely benefit these complex patients.