Gout is a disorder of nucleic acid metabolism that leads to monosodium urate crystal deposition in the joints. The most common area of the body to be affected by gout is the first toe. The radiograph in Figure A demonstrates joint space narrowing of the 1st metarsalphalangeal joint and the arrows show medial soft tissue swelling at the 1st MTP with soft tissue radio-densities and some erosive changes consistent with gout.
Weinfeld et al report their experience over a 7 year period with hallux MTP arthritis in 439 patients they treated. Surgical indications included pain, shoewear problems, and failure of non-operative management.
Reber et al describe a rare case of tophaceous gout in the medial sesamoid of the hallux and review the diagnosis, pathophysiology, and suggested management.
Eggebeen reports "gout is caused by monosodium urate crystal deposition in tissues leading to arthritis, soft tissue masses (i.e., tophi), nephrolithiasis, and urate nephropathy. The biologic precursor to gout is elevated serum uric acid levels (i.e., hyperuricemia). The diagnosis is confirmed if monosodium urate crystals are present in synovial fluid."
Answer 2: Calcium pyrophosphate deposition is found with pseudogout and tophaceous depositions are rare in this disease.
Answer 3: Renal osteodystrophy is a spectrum of disease seen in patients with chronic renal disease. It is characterized by bone mineralization deficiency due to the electrolyte and endocrine abnormalities associated with chronic kidney disease. It is common cause of hypocalcemia, but does not present with the "tophi" seen in Figure A.
Answer 4: Extrapulmonary manifestations of tuberculosis include CNS infection, vertebral body involvement (Potts Disease), renal disease, and GI symptoms. It does not present with tophi of the first MTP joint.
Answer 5: Sarcoidosis is a multisystem, chronic, inflammatory/fibrosing disease of unknown etiology. It is characterized by noncaseating granulomas that affects the lungs (90% of the cases) and other organ symptoms. It does not present with tophi of the first MTP joint.
Weinfeld SB, Schon LC. Hallux metatarsophalangeal arthritis. Clin Orthop Relat Res. 1998 Apr;(349):9-19. Review.
PMID:9584362 (Link to Abstract)
Reber PU, Patel AG, Noesberger B. Gout: rare cause of hallucal sesamoid pain: a case report. Foot Ankle Int. 1997 Dec;18(12):818-20.
PMID:9429885 (Link to Abstract)
Eggebeen AT. Gout: an update. Am Fam Physician. 2007 Sep 15;76(6):801-8. Review. PubMed PMID: 17910294.
PMID:17910294 (Link to Abstract)