Insufficiency Fracture in a Patient With Rheumatoid Arthritis in Remission Receiving Long-Term Methotrexate Without Conventional Risk Factors: A Case Report and Literature Review

Methotrexate (MTX) is the standard care for rheumatoid arthritis (RA), and it is largely tolerated with a small percentage of patients (in long-term studies) discontinuing due to side effects. MTX-associated osteopathy is an infrequent complication, which is marked by insufficiency fractures during long-term therapy even in individuals with properly controlled RA. We report the history of a 75-year-old seropositive remittent-RA patient with a history of more than 18 years of MTX therapy, complaining of nontraumatic mechanical ankle pain that has progressively caused the patient to walk with a limp. Laboratory tests, including inflammatory markers, were normal, and there was no sign of disease flare. Magnetic resonance imaging demonstrated calcaneus and distal tibia stress fractures with significant bone marrow edema, and no active synovitis. MTX-induced osteopathy was also considered in a multidisciplinary setting, which resulted in MTX withdrawal and nonpharmacological treatment using off-loading, analgesia, and the optimization of bone-targeted therapy. The clinical history was positive, and the pain gradually improved during follow-up.