Skeletal Dysplasia: Approach to Simplify Diagnosis, Looking for Radiographic Clue Signs

Skeletal dysplasia is a heterogeneous group of disorders affecting the growth of bones and cartilage. Diagnosis can be difficult for many reasons; they are over 400 diseases, and some are rare and might have atypical presentation when clinical manifestations and radiological findings might not match the classical picture of the specific disorder. The final diagnosis of a skeletal dysplasia is a combined workup that includes clinical examination, family history, radiological assessment (skeletal survey and other investigations), and finally the laboratory, molecular and genetic assessment. These all steps require tertiary centers, therefore, the primary clinical practice would require a tool-kit to help identify the most common skeletal dysplasia easily and identify the most important features of uncommon or rare disorders. The combined clinical assessment and radiological assessment can together reach this goal. 
The aim of this article is to spotlight on few important checkpoints to help the clinician and radiologist to narrow the differential diagnosis in the primary evaluation before the referral, if available, for molecular and genetic study. This article will focus on essential initial steps in diagnosis and some clue diagnostic features in the skeletal survey images that are classic for the most common disorders.