Hereditary onycho-osteodysplasia (nail-patella syndrome). A three-generation familial study.

Hereditary onycho-osteodysplasia or nail-patella syndrome is an uncommon familial musculoskeletal condition that is primarily seen initially in orthopaedic clinics. This three-generation familial review identifies three affected family members, one of whom demonstrated spondylolisthesis, a condition not previously associated with nail-patella syndrome. All affected family members demonstrated the typical radial nail dysplasias, hypoplastic patellae, iliac horns, and posterior dislocation of the radial heads. Overgrowth of the medial femoral condyles caused valgus deformities of the knees that necessitated orthotic treatment in the youngest affected family member. Although this syndrome has classic common musculoskeletal anomalies, the lumbar spine should also be carefully examined for the presence of spondylolysis and for signs of potential spondylolisthetic development.