Atypical Calf Cyst Treated With Doxycycline Sclerotherapy: A Case Report

Area of Science:

• Orthopedics
• Radiology
• Surgical Innovation

Background:

• Popliteal (Baker's) cysts are common, arising from synovial fluid accumulation, often linked to knee pathology.
• Standard treatments include aspiration, injections (corticosteroids, dextrose, sclerosing agents), and surgical excision.

Observation:

• A 58-year-old male presented with a large, unusually located synovial cyst in the lateral calf.
• Imaging confirmed intra-articular communication with the knee joint.
• The cyst recurred after aspiration and injections with dextrose/lidocaine and doxycycline.

Findings:

• Complete resolution of the synovial cyst was achieved after a final aspiration without any injectate.
• The mechanism for resolution is hypothesized to be repeated aspiration and injection, akin to longitudinal cyst fenestration.
• Doxycycline injection may have contributed to the resolution.

Implications:

• Repeated aspiration and injection could be a viable treatment for refractory synovial cysts.
• Further research into intracyst doxycycline injection followed by reaspiration warrants investigation for treating persistent cysts.