Objective      To introduce a minimal surgical treatment for severe ankle primary arthritis under arthroscope and its corresponding clinical outcome.       Methods      From July 2007 to December 2012

a total of 25 patients with ankle primary arthritis after failed conservative treatment were treated by arthroscopic arthrodesis in our hospital. Weight-bearing anteroposterior (AP) radiography and MR imagingwere performed preoperatively to identify the degree of varus/valgus deformity. Firstly

the portal was established during the surgery

and the remaining articular cartilage was removed with a combination of a debrider and curettes under direct vision. Then the foot was positioned correctly in neutral flexion with 2 cannulated percutaneous screws. The patient was mobilised non-weight bearing for 6 weeks

followed by partial weight-bearing until radiological union. Visual analogue scale (VAS) was used to evaluate the pain before and in 1 year after surgery

and the results were analyzed statistically.       Results      All ankle arthrodesis were union in a mean duration of 12±1 weeks (ranging from 10 to 16). They got pain relief and improvement in gait. One case underwent subtalar joint fusion with aid of a small incision during the arthroscopic surgery. No severe complication

such as poor wound healing or infection was found in the cohort. Two patients had complained mild pain after ankle arthrodesis and then satisfied with reservation treatment. VAS system showed all patients got pain relief after ankle arthrodesis (before 7.9±1.4vs 1 year after 2.1±0.8

P=0.005).       Conclusion      For the patients suffering from severe ankle primary arthritis

if conservation treatment is not effective

arthroscopic ankle arthrodesis is a good approach with small trauma

sound wound appearance

and high union rate. Technique and instrument are critical for success.