Epiphyseal Abnormalities Research Articles

The Morbid Anatomy of the Skeleton in Osteogenesis Imperfecta

Clinically, the two most prominent features of osteogenesis imperfecta are dwarfing and bone fragility. Radiologic examination reveals severe osteopenia with or without multiple deformities. Histological examination of samples obtained from 16 iliac crest biopsies compared with 21 age-matched controls revealed a significantly diminished amount of bone matrix without an associated decrease in the number of bone cells, suggesting a quantitative deficiency of collagen production. Radiologic studies of 46 affected children and autopsy studies of two children revealed abnormalities in the ossification of the secondary centers of ossification, together with evidence of fracture and fragmentation of the epiphyseal growth plates causing a characteristic radiologic appearance which may be likened to a bag of popcorn. These epiphyseal abnormalities may contribute to the limb shortening in some cases.

Constitutional Aspects of the Osteochondroses

The osteochondroses comprise a heterogeneous group of clinical disorders, the diagnosis of which is generally confirmed by radiologic appearances. The causes are unknown and little pathologic material has been examined to resolve this problem. Moreover, study of the affected bone yields minimal insight into the cause of the disorder because bone cells respond in a set pattern irrespective of the initial injury. Although acute trauma or prolonged abnormal mechanical forces in the region of epiphysis can lead to bone collapse and necrosis, it is unlikely that such forces are sufficient to affect normal healthy bone. The timing, distribution, multiple sites and familial etiology, as well as the close association between osteochondroses and certain congenital disorders, strongly suggest that there is constitutional epiphyseal inadequacy. The daily stresses of healthy childhood activity are enough to compromise the development of constitutionally weak epiphyses. When architectural bone collapses, the full osteochondrotic picture is manifested. Bone compaction can be brought about only by mechanical means and the force needed is inversely proportional to the degree of epiphyseal abnormality, e.g., a mildly dyschondrotic epiphysis will not present clinically without sufficient trauma to produce architectural collapse. Recent anthropomorphic studies have shown that children with Perthe's disease have a generalized growth disorder. Further long-term comprehensive biological studies are needed to provide more data on children suffering from the osteochondroses if the underlying constitutional defects are to be identified.

Juvenile Osteochondritis Dissecans of the Knee

Of 73 patients in whom 122 lesions of osteochondritis dissecans of the knee developed, nearly half had multiple lesions and 30% were of short stature. Endogenous and exogenous traumas play a minor role in the etiology of this disorder. Over half of the children with a history of trauma had bilateral and symmetrical lesions. Constitutional factors, such as hereditary predisposition, endocrine dysfunction, collagen and epiphyseal abnormalities, are frequently associated with juvenile osteochondritis dissecans of the knee.

The Langer-Giedion-syndrome (tricho-rhino-phalangeal syndrome, type II)

A 15-year-old girl with the Langer-Giedion-syndrome (tricho-rhinophalangeal syndrome, type II) is presented. The features are multiple exostoses, sparse, fine hair and an abnormal face and hands. X-ray examination reveals exostoses and abnormal epiphyses. In this case intelligence is normal; there is severe sensorineural deafness (60--80 dB hearing loss). The genetic aspects of the syndrome are discussed.

Picture of the Month

<h3>Denouement and Discussion</h3><h3>Pseudoachondroplasia (Pseudoachondroplastic Spondyloepiphyseal Dysplasia)</h3><h3>Manifestations</h3> Pseudoachondroplasia is probably the second most common chondrodystrophy next to true achondroplasia. Individuals with pseudoachondroplasia resemble achondroplastic dwarfs in having long trunks and short limbs, hence the name pseudoachondroplasia. However, in contrast to classical achondroplasia, they have normal craniofacies and are not recognizable at birth. Instead of the clearly defined roentgenographic changes present at birth in achondroplasia, vertebral and epiphyseal abnormalities evolve with time. Patients with pseudoachondroplasia are usually considered normal until 18 months to 2 years of age when they are either late to walk or have a waddling gait. They have short limbs with limitation of extension of the elbows, contractures of the hips and knees occasionally, and hyperextensibility of many other joints. This loose-jointedness increases with age, and the hands are usually held in an ulnar position. The legs are frequently bowed, but knockknee also occurs. Mild to moderate