Total Joint Arthroplasty The cost of infection after total joint arthroplasty Andrew Mulder, Sami Jaafar and David C. Markel ABSTRACT Total joint arthroplasty of the hip and knee are commonly performed procedures with excellent clinical results and survivorship of nearly 80% at 20 years for hips and up to 90% at 15 years for knees. Despite these excellent outcomes, complications do occur and can prove costly to the patient, the physician, and the health care system. A particularly costly complication is the development of postoperative infection. What follows is an evaluation of the costs related to infection after total joint arthroplasty and a description of how those costs are being approached for containment. Keywords arthroplasty, cost, infection, joint INTRODUCTION T otal joint arthroplasty (TJA) of the hip and knee is a commonly performed procedure with excellent clin- ical results and survivorship of nearly 80% at 20 years for hips and up to 90% at 15 years for knees. 1--3 The success of these procedures has made total knee arthroplasty (TKA) the second most common orthopaedic procedure performed in American adults. 4 It is projected that with the aging United States (US) population, the demand for primary total hip arthroplasty (THA) and TKA is predicted to increase by 174% and 673%, respectively, by 2030. 5 It would be expected that with advent and effective use of prophylactic antibiotics, operating room efficiencies and standards, and current fastidious surgical practices, the once painstakingly difficult and unpredictable TKA or THA should continue to flourish with great outcomes. BURDEN OF REVISION TJA Despite the overall success of TJA, failures do occur. The burden of failed TJA is carried by the health care system, the hospitals, the surgeons, and the patients. Kurtz et al. 5 estimate that the demand for revision surgery of the failed TKA and THA (for all causes) will double by 2015 and 2026, respectively. This revision burden certainly will have a significant economic effect on the system. 5--7 To quantify the economic burden of revision TJA (defined as the annual reimbursements for revision arthroplasty relative to the sum total reimbursements of primary and revision arthroplasty), Ong et al. 6 examined the trends in charges and reimbursements from Medicare Part A (hospital submitted) and Part B (physician submitted) data as they relate to TJA from 1997--2003. Using ICD-9 (Classification of Diseases, Ninth Revision, Clinical Modification) and CPT-4 (Physicians’ Current Procedural Terminology) codes, the mean economic bur- dens, as defined above, were 18.8% for revision THA surgery and 8.2% for revision TKA surgery. In monetary terms, Medicare’s annual reimbursement was $263 million for revision THA and $201 million for revision TKA. 6 These numbers were based on a projected increase in revision THA and TKA of 137% and 601%, respectively. 5 Ong et al. 6 identified a real and present concern for the industry and society as well as a significant discrepancy between the charges and the expected reimbursement for the revision surgery. BURDEN OF INFECTED TJA Although recent studies have shown infection rates in TJA near or r1% in most cases, the seriousness of failure from infection cannot be overstated. 8,9,10,11,12 The reporting, however, likely underestimates the prevalence of infection. This may be the result of a failure to diagnose or report. Despite modern imaging and diagnostic technologies, diag- nosing infection in TJA is not always easy, nor straightfor- ward. The American Academy of Orthopaedic Surgeons (AAOS) Clinical Practice Guideline Summary lists 15 recom- mendations to guide the diagnosis of periprosthetic joint infection (PJI). In addition, Della Valle et al., 13 for the Musculoskeletal Infection Society, outlined criteria for definitive diagnosis of PJI. 14 Synovial fluid white blood cell count, peripheral mononuclear cell percentage, and serum C-reactive protein and erythrocyte sedimentation rate have been well defined 15 and remain the mainstays of diagnosis. New novel inexpensive tests such as colorimetric strip testing of synovial fluid are being validated 16 to assist early diagnosis. Other nontraditional, often expensive, methods have been proposed and implemented to help identify acute and chronic infection. These methods include sonification Detroit Medical Center and Providence Hospital, Detroit, MI Financial Disclosure: Dr. Markel is a consultant for Stryker. The authors report no financial conflicts of interest. Correspondence to David C. Markel, MD, DMC-Providence Orthopaedic Residency, Orthopaedics Providence Hospital, 22250 Providence Drive #401, Southfield, MI 48075 Tel: þ 248 349 7015; fax: þ 248 569 0364; e-mail: david.markel@stjohn.org 1940-7041 r 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins SPECIAL FOCUS 554 Current Orthopaedic Practice Volume 23  Number 6  November/December 2012