From 1996, we were added fenestration between coronoid fossa, and olecranon fossa at the time of debridement arthroplasty termed extensive debridement arthroplasty with medial and lateral approach.The purpose of this study is to investigate clinical results of extensive debridement arthroplasty. 17 cases could be followed more than two years. Their averaged age was 57.3 years old. Two elbows had a previous history of debridement arthroplasty. In preoperative averaged flexion angle was 105 and averaged extension was 28C Clinical evaluation was performed with the elbow score of Japanese Orthopedic Association Preoperative averaged JOA score was 54.6 points In ray study we investigated whether the fenestration was open or closed. In all cases, their symptoms improved D All patients returned to their former occupations satisfied with the clinical results Infection postoperative fracture and ectopic ossification were not observed.The averaged JOA score was 91 points Postoperative averaged flexion was 127 averaged extention was 12_Improvement of extension was 16 and that of flexion was 22 Closure of the fenestration was observed in five elbows Osteophyte formations of the coronoid process and olecranon was seen in 4 elbows The JOA score of pain and ROM of these results were superior compared with any reports of debridement arthroplasty.The JOA score and results of ROM were superior when the fenestration was open.To maintain the fenestration hole open some modification will be necessary Short term results of extensive debridement arthroplasty showed satisfactory results in terms of pain relief and Improvement of ROM, especially in extension.