A distinct form of spondyloepimetaphyseal dysplasia with joint laxity (SEMDJL)-leptodactylic type: radiological characteristics in seven new patients

This study presents seven cases of a rare but distinctive form of spondyloepimetaphyseal dysplasia with joint laxity-leptodactylic or Hall type to emphasize the characteristic clinical and radiological findings. A multiinstitutional retrospective review was performed on seven patients. The patient population consisted of one family with an affected mother and two siblings and four unrelated patients; there were one adult, aged 40 years, and six children, ranging in age from 3 to 12 years. The gender ratio of females to males was 5 to 2. We reviewed the clinical data and skeletal surveys and focused on radiographs of the pelvis, knees, hands, and spine. The outstanding clinical features were short stature, midface hypoplasia, and multiple dislocations and/or ligamentous laxity of the large joints, particularly at the knees with a genu valgum or varum deformity. Of seven patients, six patients showed normal intellect but one patient had mild mental retardation. The main radiological features included small, irregular epiphyses, metaphyseal irregularity with vertical striations that was a constant finding at the knees, constricted femoral necks, delayed ossification of the carpal bones, and slender metacarpals. Progressive thoracolumbar scoliosis was evident with aging; however, the vertebral bodies appeared normal in height or mild platyspondyly was noted. In view of the orthopedic management of multiple joint dislocations and ligamentous laxity of the large joints, awareness of this disease entity and diagnostic precision solely based on radiological findings is of importance, particularly as the disorder is currently more common than initially reported.