ObjectiveTo evaluate the effectiveness of open arthrolysis in treatment of the patient with stiff knee in late stage after primary total knee arthroplasty (TKA).MethodsBetween January 2014 and October 2017, 7 female patients (7 knees) with stiff knee in late stage after primary TKA were admitted. The patients were 57-71 years old (mean, 63 years). There were 2 left knees and 5 right knees. All patients underwent TKA because of knee osteoarthritis. The interval between TKA and open arthrolysis was 8-30 months (mean, 13.6 months). There were 4 patients with 10-20° of extension deficit before arthrolysis. The range of motion of knee was (54.3±12.1)°. The clinical score, functional score, and total score of Knee Society Score (KSS) before arthrolysis were 76.3±7.6, 67.9±11.1, and 144.1±16.1, respectively. During the arthrolysis, periarticular soft tissue scar was removed, the range of motion of knee was restored, the gap balance and well patellar tracking were maintained. Intensive rehabilitation after operation was supplemented.ResultsAll wounds healed by first intention, without early stage complications. All patients were followed up 12-32 months with an average of 20.1 months. No abnormality of prosthesis was found by post-operative X-ray films. The knee movement improved significantly when compared with that before arthrolysis. The range of motion was less than 90° in 1 patient and 10° of extension deficit remained in 1 patient after operation. The range of motion was (92.9±4.9)° at last follow-up. The clinical score, functional score, and total score of KSS were 81.9±5.1, 74.3±9.8, and 156.1±13.7, respectively at last follow-up. The above indexes were superior to those before operation (P<0.05).ConclusionOpen arthrolysis combined with intensive rehabilitation is a significant way to improve knee function for the patient with stiff knee in late stage after primary TKA.