Risk factors for manipulation after total knee arthroplasty: a pooled electronic health record database study

A commercially available software platform, Explorys (Explorys, Inc., Cleveland, OH), was used to mine a pooled electronic healthcare database consisting of the medical records of more than 27 million patients. A total of 229,420 patients had undergone a total knee arthroplasty; 3470 (1.51%) patients were identified to have undergone manipulation under anesthesia. Individual risk factors of being female, African American race, age less than 60, BMI >30 and nicotine dependence were determined to have relative risk of 1.25, 2.20, 3.46, 1.33 and 1.32 respectively. Depressive disorder, diabetes mellitus, opioid abuse/dependence and rheumatoid arthritis were not significant risk factors. African Americans under the age of 60 at time of TKA had the greatest incidence of MUA (5.17%) and relative risk of 3.73 (CI: 3.36, 4.13).