Maria Pia Bondioni1, Ugo Ernesto Pazzaglia2, Claudia Izzi3, Giuseppe Di Gaetano4, Francesco Laffranchi4, Maurizia Baldi5, Federico Prefumo3. 1. Pediatric Radiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, P.le Spedali Civili n. 1, 25100, Brescia, Italy. mariapiabondioni@gmail.com. 2. Orthopaedic Clinic, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy. 3. Prenatal Diagnosis Unit, Department of Obstretics and Gynecology, ASST Spedali Civili of Brescia, Brescia, Italy. 4. Pediatric Radiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, P.le Spedali Civili n. 1, 25100, Brescia, Italy. 5. Genetic Laboratory Galliera Hospital Genova, Genoa, Italy.
Abstract
OBJECTIVE: The purpose of the paper was to assess the morphometric parameters to improve the specificity of the ultrasound (US) signs for the early differential diagnosis between two lethal dysplasias, as thanatophoric dysplasia (TD) and osteogenesis imperfecta type 2 (OI-2). METHOD: The diaphyseal length and the bowed shape of long bones associated with vertebral body dimension assessment were investigated in a group of 14 pregnancy terminations carried out in the time period 2007-2013. The definitive diagnosis was established after pregnancy termination by means of skeletal standardized X-rays, histopathology and gene analysis. RESULTS: TD and OI-2 long bones were significantly shorter than controls. No significant differences were observed between the two dysplasias. The bowing angle was higher in OI-2; a true angulation or eventually axial displacement was present only in the latter. Furthermore, they did not show any evidence of vertebral collapse. The thanatophoric dysplasia presented less bowed long bones, and never true angulation. The spine was steadily characterized by flattened anterior vertebral bodies. CONCLUSION: Long bone shortening is not a sufficient and accurate sign for early sonographic differential diagnosis between TD and OI-2. Angled diaphysis, axial diaphyseal displacement and a conserved vertebral body height in the prenatal period support the diagnosis of osteogenesis imperfecta type 2, while moderately regular bowed diaphysis associated with platyspondyly that of thanatophoric dysplasia.
OBJECTIVE: The purpose of the paper was to assess the morphometric parameters to improve the specificity of the ultrasound (US) signs for the early differential diagnosis between two lethal dysplasias, as thanatophoric dysplasia (TD) and osteogenesis imperfecta type 2 (OI-2). METHOD: The diaphyseal length and the bowed shape of long bones associated with vertebral body dimension assessment were investigated in a group of 14 pregnancy terminations carried out in the time period 2007-2013. The definitive diagnosis was established after pregnancy termination by means of skeletal standardized X-rays, histopathology and gene analysis. RESULTS: TD and OI-2 long bones were significantly shorter than controls. No significant differences were observed between the two dysplasias. The bowing angle was higher in OI-2; a true angulation or eventually axial displacement was present only in the latter. Furthermore, they did not show any evidence of vertebral collapse. The thanatophoric dysplasia presented less bowed long bones, and never true angulation. The spine was steadily characterized by flattened anterior vertebral bodies. CONCLUSION: Long bone shortening is not a sufficient and accurate sign for early sonographic differential diagnosis between TD and OI-2. Angled diaphysis, axial diaphyseal displacement and a conserved vertebral body height in the prenatal period support the diagnosis of osteogenesis imperfecta type 2, while moderately regular bowed diaphysis associated with platyspondyly that of thanatophoric dysplasia.
Entities:
Keywords:
Comparative morphometry; Osteogenesis imperfecta 2; Short and bent long bones; Thanatophoric dysplasia
Authors: Barbara V Parilla; Elizabeth A Leeth; Michelle P Kambich; Patricia Chilis; Scott N MacGregor Journal: J Ultrasound Med Date: 2003-03 Impact factor: 2.153
Authors: Lyn S Chitty; Asma Khalil; Angela N Barrett; Eva Pajkrt; David R Griffin; Tim J Cole Journal: Prenat Diagn Date: 2013-02-14 Impact factor: 3.050