Digital mucous cysts (DMCs) are a benign rubbery cystic lesion which usually involve the dorsal or lateral side of DIP joint (digital interphalangeal joint) or proximal nail fold. The most successful treatment way is surgical management. However, which may cost time, require expertise, may cause infection, prolong wound healing and sometimes may lead to the joint movement limitation. The investigator bring this new technique: percutaneous capsulotomy for digital mucous cysts, which is easy and quick, last but not least, low recurrence rate.

Participant

Between 2016 and 2017, 50 participants with DMCs in Taipei veteran general hospital were included in this study. According to the clinical assessment at OPD(out participants department), DMC was diagnosed. Serial related serial clinical features of DMCs were investigated including participant's age, location, size of cysts, symptoms, duration, nail bed condition, underlying disease(ex. rheumatoid disease, Diabetes) and previous treatment. After explaining to participants about the treatment choice (surgical excision, aspiration of cystic contents, and our needle assisted percutaneous capsulotomy for mucous cyst) and participants agreed with accepting needle assisted percutaneous capsulotomy, they were selected for accepting our needle assisted percutaneous capsulotomy for mucous cyst.

Surgical capsulotomy procedure.

The surgical procedure for DMCs was using a 18G needle performing aspiration first and then cutting the stalk tract by the needle tip for capsulotomy. All procedure were done with local anesthesia. After operation, the investigator asking participants using dressing to pressure the wound about 10 minutes to stop bleeding. Later on, the wound was covering with antimicrobial ointment (neomycin) and simple dressing. Educating participants from water for 24 hrs.

Clinical assessments

The investigator evaluating participant's prognosis by VAS, the improvement of fingernail deformity, the participants' subjective satisfaction and the recurrences was evaluating during follow-ups. This clinical study's approval was obtained from Association of IRB, Taipei veteran general hospital.

Inclusion Criteria:

• According to the clinical assessment at OPD(out patient department), DMC was diagnosed. Serial related serial clinical features of DMCs were investigated including pateint's age, location, size of cysts, symptoms, duration, nail bed condition, underlying disease(ex. rheumatoid disease, Diabetes) and previous treatment

Exclusion Criteria:

• autoimmune disease related diffused arthritis, age younger than 20 year-old, severe painful deformity of the involved joint.

According to the clinical assessment at OPD(out patient department), DMC was diagnosed. Serial related serial clinical features of DMCs were investigated including pateint's age, location, size of cysts, symptoms, duration, nail bed condition, underlying disease(ex. rheumatoid disease, Diabetes) and previous treatment