Arthroscopic management of large subchondral talar cyst: a novel treatment strategy.

Subchondroplasty is a novel and minimally invasive technique used to treat large subchondral talar cysts. It avoids soft tissue scarring, the need for osteotomies, bone grafting and its associated complications as seen with conventional approaches. Subchondroplasty involves arthroscopically approaching the cyst and injecting it with calcium phosphate paste injection, which undergoes an endothermic process and crystallizes in a manner that resembles cancellous bone to fill the defect. This case series presents two patients who underwent subchondroplasty: a 44-year-old female nurse with atraumatic right ankle pain of 2 years with a CT scan revealing a large subchondral cyst over the medial talar dome and a 55-year-old male chemical plant worker with left ankle pain following a biking accident 6 years ago whose CT scan too showed a large subchondral cyst in the medial talus. Both tolerated the surgery well, with significant reductions noted in MOXFQ scores at the 1-year follow-up.