Reconstruction of Nonrheumatic Boutonnière Deformity in Bilateral Thumbs Using Different Approaches With Distinct Outcomes.

Boutonnière deformity of the thumb is a rare condition primarily caused by noninflammatory conditions and is most commonly associated with rheumatoid arthritis. Traumatic boutonnière deformities of the thumb have rarely been documented. This report presents a unique case of bilateral thumb boutonnière deformity in a 53-year-old female patient. Each thumb was treated using different surgical approaches in separate medical institutions, leading to markedly different outcomes. The right thumb underwent permanent arthrodesis of the metacarpophalangeal joint by an orthopedic surgeon at another hospital, resulting in a limited range of motion. Our plastic surgeon treated the left thumb by repairing the ruptured dorsoradial capsule and severing the extensor pollicis brevis tendon, restoring full thumb function. This case highlights the differences in etiology and treatment approaches for boutonnière deformity in the thumb as opposed to the fingers and emphasizes the importance of thorough clinical evaluation and tailored surgical interventions. Successful outcomes in thumb deformities rely on a precise diagnosis, particularly distinguishing among ligament, capsular, and bony lesions, and selecting the appropriate treatment strategy.