Figure 5. Photographs of the nails and radiographs of knees, hips and elbows of some of the subjects. Nail involvement in these cases includes dystrophic, thin, hypoplastic discolored nails with longitudinal ridges. Case III-2 shows decreased creases over the skin of distal interphalangeal joints, which is a sensitive sign of digital involvement in this patient (A). Thumbs are most severly affected in case III-7 (B), and IV-9 (C). The radiographs of knee involvement in Case III-2 shows bilateral involvement of the patella, with hypoplastic, higher than normal missplaced patella (D-F). A small 6 mm bone fragment can be observed on the lateral border of right patella (E). Knee radiographs of Case III-7 show slight bilateral patellar hypoplasia, mostly on the transverse diameter (G and H). Hip radiography of Case IV-2 shows loss of the normal concavity at the junction between the head and femoral neck bilaterally. The radiographs reveal an elbow involvement of subject IV-2 (J and K) and include a prominent medial epicondyle and hypoplasia of the capitellum on both sides (J and K). They also show a hypoplasia of the lateral epicondyle and capitellum with a slight deformity of the radial head (J and K). Underdeveloped triceps and prominent medial epicondyle are observed (L).