The study by Bozic et al. (2009) examines the epidemiology of revision total knee arthroplasty (TKA) in the United States, focusing on the causes of failure and the types of revision procedures performed. Using data from the Nationwide Inpatient Sample (NIS) database, the authors analyzed 60,355 revision TKA procedures conducted between October 1, 2005, and December 31, 2006. The most common causes of revision TKA were infection (25.2%) and implant loosening (16.1%), with all component revision being the most frequent type of procedure (55.2%). The procedures were predominantly performed in large, urban, non-teaching hospitals for Medicare patients aged 65 to 74. The average length of hospital stay was 5.1 days, and the average total charges were $49,360. However, these averages varied significantly by census region, hospital type, and procedure type. The study highlights the importance of understanding the causes of TKA failure and the types of revision procedures to improve implant performance and patient outcomes. The newly implemented ICD-9-CM diagnosis and procedure codes for revision TKA provide valuable insights but require further education and training to ensure accurate coding.The study by Bozic et al. (2009) examines the epidemiology of revision total knee arthroplasty (TKA) in the United States, focusing on the causes of failure and the types of revision procedures performed. Using data from the Nationwide Inpatient Sample (NIS) database, the authors analyzed 60,355 revision TKA procedures conducted between October 1, 2005, and December 31, 2006. The most common causes of revision TKA were infection (25.2%) and implant loosening (16.1%), with all component revision being the most frequent type of procedure (55.2%). The procedures were predominantly performed in large, urban, non-teaching hospitals for Medicare patients aged 65 to 74. The average length of hospital stay was 5.1 days, and the average total charges were $49,360. However, these averages varied significantly by census region, hospital type, and procedure type. The study highlights the importance of understanding the causes of TKA failure and the types of revision procedures to improve implant performance and patient outcomes. The newly implemented ICD-9-CM diagnosis and procedure codes for revision TKA provide valuable insights but require further education and training to ensure accurate coding.