Orthopedics - Oleksa A.P. 2006

Pathophysiology of Joints
Developmental Disorders and Congenital Skeletal Anomalies
Enchondral Metaepiphyseal Dysostosis

The first descriptions of this disease and attempts to distinguish it from the classic form of Achondroplasia were made by Pfaundler and Hurler, later followed by Jansen, Ribbing and Muller, Morquio and Brailsford, among others.

Enchondral dysostosis (dysostosis enchondralis) is described in the literature under various names: atypical chondrodystrophy, systemic osteochondropathy, systemic joint hypoplasia, multiple or polyepiphyseal Dysplasia, Spondyloepiphyseal Dysplasia, etc.

Brailsford proposed the term "chondroosteodystrophy," while S. A. Reinberg (1964) referred to this condition as "osteochondrodystrophy."

The most rational designation is "dysostosis enchondralis epiphysarea resp. metaphysarea," introduced by Jansen. It corresponds most closely to The Nature and Specific features of the pathology.

Enchondral Metaphyseal Dysostosis occurs more frequently than other systemic skeletal disorders and constitutes a completely independent nosological entity. It is hereditary and may affect several members of the same family (Jacobson, Ribbing et al.). Some researchers suggest that the disease may result from parental intoxication or other illnesses.

The Essence of enchondral dysostosis lies in the involvement of the ossification centers of the epiphyses of the long BONES OF THE limbs, pelvis, and spine, and occasionally the small bones of the hands and feet. Consequently, the transition of Cartilage tissue into bone is delayed, beginning as early as the Initial Stages of fetal intrauterine development and the early phases of bone growth. Periosteal bone growth remains unaffected.

Clinical manifestations of the disease vary, but the hallmark feature is short stature resulting from shortened, deformed limbs, trunk, and spine (dwarfism).

Cocchi classifies all types of enchondral dysostosis into three groups. The first group includes polytopic enchondral dysostoses inherited in an autosomal dominant manner without corneal clouding (Leri type). The second group comprises polytopic enchondral dysostoses inherited recessively without corneal clouding (Morquio type). The third group encompasses polytopic enchondral dysostoses with recessive inheritance accompanied by corneal clouding (Pfaundler-Hurler type).

Weil classifies metaphyseal enchondral dysostosis into:

1) a proportional form — the Ribbing-Muller type with multiple epiphyseal dysplasia;

2) a disproportionate form — the Morquio-Brailsford type characterized by more pronounced multiple epiphyseal dysplasia and metaphysical involvement without Metabolic Disorders;

3) the Pfaundler-Hurler type featuring similar skeletal changes but accompanied by metabolic disturbances.