Rationale:Ankle syndesmotic injuries occasionally require long-term therapy for recovery and can result in tendon injury. Posterior tibial tendon dysfunction (PTTD) is an acquired deformity that can cause flatfoot deformity. The current nonoperative management of PTTD includes nonsteroidal antiinflammatory drugs (NSAIDs), orthopedic devices. Although various treatment options have been attempted, optimal treatments for each stage of the condition are debated. Polydeoxyribonucleotide (PDRN) is effective in healing of chronic wounds associated with tissue damage by attracting tissue growth factors.Patient concerns:A 67-year-old woman who presented at our pain clinic with pain on the inside of ankle. She had a syndesmotic screw fixation 3 years prior. Her ankle pain had persisted after the removal of screws and edema for about 1 month resulting from long-term NSAIDs administration.Diagnoses:The origin of the pain was possibly tibialis posterior muscle and posterior tibial tendon and she was diagnosed as PTTD after syndesmosis surgery.Interventions:Sono guided prolotherapy with PDRN was carried out.Outcomes:Patient showed improvement in the arch of the foot, experienced pain relief, and was able to wear regular shoes without any orthopedic device.Lessons:This case report highlights that PDRN prolotherapy is a safe and efficient therapeutic option for the treatment of PTTD.