Arthrofibrosis following total knee arthroplasty (TKA) is a debilitating complication. Treatment options include physical manipulation under anesthesia (MUA), and arthroscopic lysis of adhesions kAL with or without MUA. the authors studied 70 patients with arthrofibrosis after TKA treated with MUA or ALOA plus MUA. In this matched cohort study, 35 patients were treated with MUA and 35 patients were treated with ALOA plus Total knee arthroplasty followed by MUA was performed by 2 surgeons and TKA followed by MUA plus ALOA was performed by 1 surgeon at 1 institution. Electronic records were used to collect information and match cohorts based on age, sex, body mass index, diabetes mellitus, perioperative range of motion (ROM), and timing of the procedure for arthrofibrosis. The combination of MUA and ALOA yielded changes in ROM: a 72.7% increase 4 to 12 weeks after index TKA (P = .032), a 50,0% increase 12+ weeks after TKA (p=.032), and a 99.8% increase in patients with a pre-manipulation ROM of 0 degrees to 60 degrees (P=.001). Manipulation under anesthesia yielded a 49.2% increase 4 to 12 weeks after TKA (p=.161), a 27.0% increase 12+ weeks after TKA (P=.161), and a 68.8% increase in patients with pre-manipulation ROM of to 60 degrees (P=.084). Patients treated with ALOA plus MUA had greater increases in ROM (P=.026) and final knee flexion (P=.028) compared with those treated with MUA alone. Arthrofibrosis following TKA is a complication that often requires additional procedures. Traditionally, ALOA is added 3+ months from index TKA, when abundant scar formation has occurred. This study found a. benefit to ALOA plus MUA compared with MUA alone, with the largest benefit in patients whose pre-manipulation ROM was 0 degrees to 60 degrees.