The Mayo Prosthetic Joint Infection Risk Score
The Mayo Prosthetic Joint Infection Risk Score
Objective. The goal of this study was to develop a prognostic scoring system for the development of prosthetic joint infection (PJI) that could risk-stratify patients undergoing total hip (THA) or total knee (TKA) arthroplasties.
Design. Previously reported case-control study.
Setting. Tertiary referral care setting from 2001 through 2006.
Methods. A derivation data set of 339 cases and 339 controls was used to develop 2 scores. A baseline score and a 1-month-postsurgery risk score were computed as a function of the relative contributions of risk factors for each model. Points were assigned for the presence of each factor and then summed to get a subject's risk score.
Results. The following risk factors were detected from multivariable modeling and incorporated into the baseline Mayo PJI risk score: body mass index, prior other operation on the index joint, prior arthroplasty, immunosuppression, ASA score, and procedure duration (c index, 0.722). The 1-month-postsurgery risk score contained the same variables in addition to postoperative wound drainage (c index, 0.716).
Conclusion. The baseline score might help with risk stratification in relation to public reporting and reimbursement as well as targeted prevention strategies in patients undergoing THA or TKA. The application of the 1-month-postsurgery PJI risk score to patients undergoing THA or TKA might benefit those undergoing workup for PJI.
It is estimated that by 2030, 4 million total hip (THA) or knee (TKA) arthroplasties will be performed annually in the United States. Although the overall outcome of THA or TKA is excellent, prosthetic joint infection (PJI) is a rare (<2% of procedures) but recognized complication that causes significant morbidity and mortality. The attributable financial cost of management of each episode of PJI is estimated to be 3–4 times the cost of a primary total joint arthroplasty, exceeding $50,000. Successful treatment of these infections is difficult. Not all patients can be successfully reimplanted with a new joint prosthesis.
Identification of high-risk patients undergoing THA or TKA can lead to better risk stratification in surgical site infection (SSI) reporting and targeted prevention strategies. In addition, patients identified to be at high risk of PJI can be processed in different diagnostic care process models if they present with wound drainage, joint pain, or other signs suggestive of PJI. A high National Nosocomial Index score (NNIS); the presence of a systemic malignancy, rheumatoid arthritis, or diabetes mellitus; a lack of appropriate antimicrobial surgical prophylaxis; the presence of a distant organ infection; and prior surgery on the index joint have all been associated with an increased risk of PJI in patients undergoing THA or TKA. The goal of the proposed study was to develop both a baseline and a 1-month-postsurgery risk-scoring system that would take into account the cumulative risk of PJI associated with multiple factors in patients undergoing THA or TKA, by using the data from a previously published case-control study. We also compared the newly developed baseline and 1-month-postsurgery risk scores to the currently utilized National Healthcare Safety Network (NHSN) risk adjustment scheme.
Abstract and Introduction
Abstract
Objective. The goal of this study was to develop a prognostic scoring system for the development of prosthetic joint infection (PJI) that could risk-stratify patients undergoing total hip (THA) or total knee (TKA) arthroplasties.
Design. Previously reported case-control study.
Setting. Tertiary referral care setting from 2001 through 2006.
Methods. A derivation data set of 339 cases and 339 controls was used to develop 2 scores. A baseline score and a 1-month-postsurgery risk score were computed as a function of the relative contributions of risk factors for each model. Points were assigned for the presence of each factor and then summed to get a subject's risk score.
Results. The following risk factors were detected from multivariable modeling and incorporated into the baseline Mayo PJI risk score: body mass index, prior other operation on the index joint, prior arthroplasty, immunosuppression, ASA score, and procedure duration (c index, 0.722). The 1-month-postsurgery risk score contained the same variables in addition to postoperative wound drainage (c index, 0.716).
Conclusion. The baseline score might help with risk stratification in relation to public reporting and reimbursement as well as targeted prevention strategies in patients undergoing THA or TKA. The application of the 1-month-postsurgery PJI risk score to patients undergoing THA or TKA might benefit those undergoing workup for PJI.
Introduction
It is estimated that by 2030, 4 million total hip (THA) or knee (TKA) arthroplasties will be performed annually in the United States. Although the overall outcome of THA or TKA is excellent, prosthetic joint infection (PJI) is a rare (<2% of procedures) but recognized complication that causes significant morbidity and mortality. The attributable financial cost of management of each episode of PJI is estimated to be 3–4 times the cost of a primary total joint arthroplasty, exceeding $50,000. Successful treatment of these infections is difficult. Not all patients can be successfully reimplanted with a new joint prosthesis.
Identification of high-risk patients undergoing THA or TKA can lead to better risk stratification in surgical site infection (SSI) reporting and targeted prevention strategies. In addition, patients identified to be at high risk of PJI can be processed in different diagnostic care process models if they present with wound drainage, joint pain, or other signs suggestive of PJI. A high National Nosocomial Index score (NNIS); the presence of a systemic malignancy, rheumatoid arthritis, or diabetes mellitus; a lack of appropriate antimicrobial surgical prophylaxis; the presence of a distant organ infection; and prior surgery on the index joint have all been associated with an increased risk of PJI in patients undergoing THA or TKA. The goal of the proposed study was to develop both a baseline and a 1-month-postsurgery risk-scoring system that would take into account the cumulative risk of PJI associated with multiple factors in patients undergoing THA or TKA, by using the data from a previously published case-control study. We also compared the newly developed baseline and 1-month-postsurgery risk scores to the currently utilized National Healthcare Safety Network (NHSN) risk adjustment scheme.
