Fractures occurring at the site of a tophus have rarely been described in gout. In this paper we review the occurrence, clinical features, and outcome of fractures in tophaceous gout.
A PubMed search was conducted to identify the relevant literature, following our experience with two patients who developed tophaceous fractures after minor or no trauma.
A total of 13 patients were analysed. Eleven cases of tophaceous fracture have been reported since 1950. Common features are: known and long-standing gout with tophi; minor or absence of trauma; specific locations include seven patients with patella bone fractures. Other sites include the cervical spine in two patients, the first and fifth metatarsal, and a phalanx in one patient each, the ilium and pubic bones in one, the medial malleola, and the femoral neck in the latter case.
Monosodium urate (MSU) crystals can contribute to bone lesions by reducing osteoblastic activity and are associated with enhanced osteoclast activity in the vicinity of tophi. Mild trauma triggers MSU crystal release from tophi, resulting in cell activation and production of cytokines and proteases. This could enhance bone erosion leading ultimately to bone fragility and fracture. Our cases exemplify a rare cause of spontaneous fracture. Gouty tophus should be considered when facing a lytic lesion with fracture.