Gout is a metabolic disorder that most commonly involves the feet, especially the first metatarsophalangeal joint, as well as the ankles, knees, hands, and elbows in asymmetric fashion. It is produced by a deposition of monosodium urate crystals in tissues with a poor blood supply, such as cartilage, tendon sheaths, and bursae. The radiographic features of gout typically do not appear until after 4 to 6 years of episodic arthritis. Radiographic features characteristic of gout include the following:
- Tophi or periarticular soft-tissue nodules/masses created by the deposition of urate crystals that may contain calcium.
- Tophi-induced periarticular or intra-articular bone erosion. Prominent cortical edges overhanging the tophi and well-defined bone erosions (with sclerotic margins) (Fig. 6-41) (54).
- Random distribution, without marked osteoporosis.