Levofloxacin-induced gastrocnemius tendon rupture: a case report.

Background: Fluoroquinolone group antibiotics are frequently used in various infections such as urinary system, respiratory system, skin, and soft tissue infections owing to their broad spectrum and good antibacterial activity. Various tendon pathologies, especially tendinopathy, have been reported in literature most commonly in the Achilles tendon, but gastrocnemius tendon rupture has never been documented.

Case presentation: A 58-year-old Caucasian white female patient had knee and calf pain that started 10 days after levofloxacin treatment. Various differential diagnoses were excluded, and finally a knee magnetic resonance image scan was performed owing to the patient's history of diabetes and levofloxacin use 10 days prior. A significant effusion was detected in the lateral gastrocnemius muscle, and millimetric hypointense free tendon fragments were seen within the effusion. Therefore, gastrocnemius tendon rupture was diagnosed, and bed rest, extremity elevation, 900 mg acetaminophen, and cold application therapy were provided. During follow-up, the patient's extremity pain subsided, and walking function improved.

Conclusion: By presenting this case, we aim to remind clinicians to keep in mind the rare tendon rupture possibilities other than Achilles tendon during fluoroquinolone group antibiotic therapy.