summary TKA Stiffness is a common complication following TKA that results in poor postoperative functional outcomes. Diagnosis is made clinically in a patient with a TKA who has flexion < 90 degrees or a flexion contracture of 10-15 degrees. Treatment is manipulation under anesthesia for flexion < 90 degrees within first 12 weeks of surgery. Arthroscopic lysis of adhesions is indicated for flexion < 90 degrees after 12 weeks. Epidemiology Incidence 1.3%-12% Risk factors preoperative factors poor preoperative ROM login to view 1 more bullet patella baja younger age (< 55) smoking increased medical comorbidities low pain tolerance prior surgery technical factors overstuffing patellofemoral joint malrotation tight flexion and/or extension gaps joint line elevation excessive tightening of extensor mechanism during closure login to view 1 more bullet tight PCL in cruciate-retaining prosthesis postoperative factors delayed rehabilitation infection HO hamstring spasms usually resolves within 6 months Presentation Symptoms difficulty kneeling Physical exam check preoperative ROM from records flexion contracture 10-15 degrees flexion < 90 degrees Imaging Radiographs rule out prosthesis malposition or alignment CT scan rule out prosthesis malposition or alignment Studies Serum labs ESR/CRP must rule-out infection Treatment Nonoperative manipulation under anesthesia indications login to view 4 more bullets contraindications login to view 2 more bullets Operative arthroscopic lysis of adhesions with manipulation under anesthesia indications login to view 1 more bullet revision total knee arthroplasty indications login to view 1 more bullet