End-Stage Tibiotalar Osteoarthritis and Chronic Strontium Toxicity

Abstract

Category: Ankle Arthritis; Ankle Introduction/Purpose: Metal toxicity due to environmental sources or orthopedic implants has been a primary focus in recent literature. Specifically, in orthopedics, total joint arthroplasty regarding metal-on-metal articulation with cobalt-chromium articulation has adverse local and systemic effects. In particular, strontium toxicity is less known metal toxicity that can cause many systemic effects such as severe osteoporosis. Methods: This is the first reported case of strontium toxicity and end-stage tibiotalar osteoarthritis. Results: We present a case of a 68-year-old female with bilateral ankle pain and deformity that were refractory to conservative measures, including physical therapy and anti-inflammatory medications. She was diagnosed with bilateral osteoarthritis and osteoporosis secondary to strontium toxicity by exclusion after extensive workup with a multi-disciplinary approach. The patient pursued conservative measures with ankle-foot orthosis, physical therapy, and anti-inflammatory medications. After the failure of conservative measures with over two years of follow-up, we recommended operative intervention to improve function and pain with staged bilateral tibiotalocalcaneal fusions utilizing an intramedullary device. Since she is moving out of state, she chose to pursue operative intervention at a different institution in order to establish long-term follow-up. The patient was placed on teriparatide for her osteoporosis secondary to strontium toxicity. Conclusion: Low doses of strontium can be beneficial to bone health and improve adverse events relating to osteoporosis. However, high doses of strontium can be detrimental leading to severe systemic complications. Although strontium toxicity is quite rare, this case demonstrates its deleterious effects on the quality of the bone leading to debilitating osteoarthritis and significant deformity in the foot and ankle.