 The data collection for the third category of outcomes, post-operative function, will begin at POD1. Ability to ambulate will be measured in distance by feet at POD1 and POD2. Furthermore, assessment of any use of assisted device for ambulation wheelchair, walker, 4-point cane, and 1-point cane will be done at POD1, POD2, 2-week followup, 6-week followup, 12-week followup and 1-year followup. Quadriceps strength and range of motion ROM will be recorded at 2-week followup, 6-week followup, and 12-week followup. Quadriceps strength will be measured on a 5-point scale, where 0 is no movement and 5 is full strength. ROM will be measured in degrees of motion. Next, the necessity of performing a manipulation under anesthesia MUA due to limited joint motion will be recorded at 6-week followup and 12-week followup. The type of PT will be recorded at 2-week followup, 6-week followup, and 12-week followup. Types of PT include out-patient PT, home health PT, PT rehabilitation, and skilled nursing facility PT. 