Bilateral calcaneal insufficiency fractures due to chronic carbamazepine use for trigeminal neuralgia: A case report

Abstract

Stress fractures of calcaneus are uncommon cause of heel pain. Stress fractures could be seen in risc groups such as metabolic diseases/medications causing poor bone quality and exposing repetitive microtrauma. Anti-epileptic drug (AED) use is related with poor bone quality and increased fracture risc. Although carbamazepine-induced stress fracture is a well-known entity and there are case reports in other bones such as the femoral neck, bilateral calcaneal insufficiency fractures is an extraordinary location. To the best of our knowledge, this is the first case reporting an insufficiency fracture involving calcaneus in the relevant literature. Due to the rarity of both conditions, we decided to present and discuss this patient. When patients receiving AED treatment present with heel pain without previous plantar fasciitis history or traumatic event, insufficiency fractures should be kept in mind. This case highlights the importance of screening adverse effect of CBZ on bone metabolism in patients with long CBZ use. We report here a 41-year-old lady suffering from bilateral heel pain without trauma history. Her complaining did not respond to analgesics and stretching exercises of plantar fascia. In her past medical history she reported ongoing carbamazepine (CBZ) use over 8 years for trigeminal neuralgia. She had had low bone mineral density; defined as osteopenia. Both calcaneus MRI revealed bilateral stress fractures of calcaneum. She had been advised immobilization for 6 weeks, vitamin D and calcium supplements. CBZ has been stopped by neurology specialist and she had undergone microvascular decompression surgery for intractable pain of trigeminal neuralgia. She is doing well with full recovery from heel pain and trigeminal neuralgia at the end of one year. CBZ use causes poor bone quality through vitamin D metabolism. Heel pain without traumatic event, objective findings of plantar fasciitis and calcaneal spur syndrome in an CBZ using patient insufficiency fracture of calcaneus should be remembered and evaluated rigorously.