Bone Abstracts

Background: Metaphyseal chondrodysplasias with cone-shaped epiphyses and cup-shaped metaphyses are very rare. We present a case with this particular skeletal phenotype, along with its differentials.

Presenting Problem: Our female patient, aged 3.8 years, was the 2nd child of healthy, unrelated Greek parents, who were worried about her bilateral knee stiffness, which resulted in a limp and also in walking with her knees bent. At presentation, she was noted to have short stature, internal rotation of the left leg and lordosis. She was otherwise normal on examination and not dysmorphic.

Clinical management: A comprehensive orthopaedic review and a full endocrine work up were undertaken. Her biochemical profile, including bone metabolism, was normal. Her X-rays of the lower limbs from the level of the knee joints to the ankles demonstrate major deformities. The distal metaphyses of the femurs and proximal metaphyses of the tibiae are enlarged and deepened, becoming cup-shaped by enlarged and cone-shaped epiphyses. Least marked changes are also present in the distal end of the tibiae. Her upper limbs and spine X-rays were normal.

Discussion: The main differentials of the isolated cone-shaped epiphyses at the knees include rare disorders such as trichoscyphodysplasia (which also includes facial dysmorphism and ectodermal dysplasia) and acroscyphodysplasia (which is accompanied by brachydactyly and psychomotor delay). In addition, it has been described in cases of vitamin C deficiency and hypervitaminosis A. None of the above features was present in our case. Lastly, this rare entity has been characterized as redisual deformity after meningococcemia. Interestingly, our patient had a history of neonatal septicaemia (due to Klebsiella Pneumoniae and Serratia Marcescensis) and this event could possibly (and by exclusion) be related to her dinstict skeletal phenotype.

Disclosure: The authors declared no competing interests.