Nail-bone quadruple

Refers to the nail-bone quadrilateral sign, which refers to the lack of toenail or hypoplasia, the loss of unilateral or bilateral metatarsal bones, or the hypoplasia of posterior metatarsal bone spurs, elbow and metatarsal deformities. Nail-patellasyndrome is also known as hereditaryosteo-onychodysplasia; hereditaryosteo-onychodysplasia; nail knee syndrome; nail knee syndrome; onychomycosis syndrome; It is a hereditary disease characterized by dysplasia or loss of the sacrum, dystrophy of the nails, elbow dysplasia, sacrum angle and renal failure. The clinical features of this disease are the nail-bone quadrilateral sign: (1) nail defects or dysplasia; (2) sacral hypoplasia or absence; (3) posterior sacral bone spurs; (4) elbow and hip valgus deformities .