Skeletal Features of Osteogenesis Imperfecta

Osteogenesis imperfecta is associated with multiple skeletal changes. Mutations in the alpha chain of collagen molecules make the bones excessively fragile. Also, prolonged immobilization and muscle wasting cause secondary bone loss. All of this is revealed in a recent study in the Journal of the Association of Physician of India (JAPI).

The research is a case study of a 38-year-old male who was admitted with generalized body ache. He was diagnosed with Osteogenesis imperfecta type III. On examination, the patient was found to have a triangular face, dentinogenesis imperfect, pectus carinatum, saber tibia, and severe kyphoscoliosis. X-ray of the chest revealed bent and deformed ribs with generalized cortical bone thinning. X-ray of the skull revealed multiple wormian bones. X-ray of the foot revealed thinning of metatarsals. CT scan of the brain revealed typical features of basilar impression. A lateral X-ray of the vertebrae revealed severe osteopenia with the collapse in multiple sites.

There was no blue sclera and hearing was normal. Unfortunately, due to poverty, he had not received medical supervision or any specific therapy like bisphosphonate from childhood. He had had multiple histories of fractures of long bones but each time, he had received only emergency care.

Such bones are liable to fracture and bend easily. That is the reason for the markedly bent ribs seen inpatient. Basilar impression (BI) is a serious craniocervical malformation seen in some cases. There is an upward displacement of the basilar and condylar portion of the occipital bone, causing infolding of the foramen magnum and translocation of the upper cervical vertebrae in the brainstem region.

So the researchers concluded this condition can remain asymptomatic, as in this case, or may give rise to serious neurological consequences. Thus, screening for Basilar impression in Osteogenesis imperfecta patients is needed, even if asymptomatic. Axial and/or sagittal CT scan or magnetic resonance imaging scan of the craniocervical region can help in the early diagnosis of the condition.

Reference: Paul R, Mondal PK, Gayen BK, et al. Skeletal Features of Osteogenesis Imperfecta. J Assoc Physicians India 2022;70(8):91–92.