Current Evidence
A uniform definition specific to periprosthetic joint infection (PJI) did not exist until recently. The new definition provided by the Musculoskeletal Infection Society (MSIS),1 for adoption in clinical and research use, is presented in Table 1.1. PJI is present if one of two major criteria or four of six minor criteria are met.
It is important to recognize that PJI may be present with fewer than four of the minor criteria, and a surgeon's judgment remains critical in identifying patients with PJI. Infections with low-virulence organisms such as Propionibacterium acnes may be particularly difficult to diagnose and may not meet all of the above criteria.
A more cumbersome definition of joint and bursa infection has also been provided by the Centers for Disease Control (CDC).2 An infection is considered present if the patient has (1) positive cultures from joint fluid or synovial biopsy; (2) evidence of joint infection seen during surgery or on histological analysis; or (3) at least two of the following without other causes: joint pain, swelling, tenderness, heat, evidence of effusion, or limitation of motion. One of these criteria must be present in conjunction with one of the following: (1) positive Gram stain; (2) synovial fluid cell type analysis and chemistry studies consistent with infection and not explained by other diseases; (3) positive antigen test on blood, urine, or joint fluid; or (4) radiographic evidence of infection. This definition is notably broad and leaves significant interpretation to the physician. It also incorporates Gram stain results, the use of which has been discouraged in diagnosing PJI.3–65
Other authors have used various definitions of PJI for classifying cohorts of PJI patients. These definitions have consisted of various combinations of tissue culture, erythrocyte sedimentation rate, C-reactive protein, joint fluid analysis (leukocyte count and neutrophil percentage), intraoperative purulence, draining sinus tract, and histological analysis.7–12 Significant variance exists between these definitions and diagnosis of PJI cases.13
Controversies
- It may be possible to have an “occult” infection that does not meet four of six criteria specified by the MSIS definition.
- The utility of histological analysis remains debatable, as the thresholds for inflammatory signs characteristic of PJI on frozen section are unproven.16 Histological analysis in diagnosing PJI is highly operator dependent and requires an experienced pathologist collaborating with the surgical team.
- Appropriate duration of tissue culture continues to be debated. Evidence exists that longer culture duration improves sensitivity without increasing contaminant growth.17
References
- CDC/NHSN Surveillance definition of healthcare-associated infection and criteria for specific types of infections in the acute care setting. 2012. Available at: www.cdc.gov/nhsn/PDFs/pscManual/17pscNosInfDef_current.pdf.
- Della Valle CJ, Scher DM, Kim YH, et al. The role of intraoperative Gram stain in revision total joint arthroplasty. J Arthroplasty. 1999;14(4):500-4. Available at: Accessed July 23, 2011.
- Ghanem E, Ketonis C, Restrepo C, Joshi A, Barrack R, Parvizi J. Periprosthetic infection: where do we stand with regard to Gram stain? Acta Orthop. 2009;80(1):37-40. Available at: Accessed July 23, 2011.
- Johnson AJ, Zywiel MG, Stroh DA, Marker DR, Mont MA. Should gram stains have a role in diagnosing hip arthroplasty infections? Clin Orthop Relat Res. 2010;468(9):2387-91. Available at: Accessed December 28, 2011.
- Morgan PM, Sharkey P, Ghanem E, et al. The value of intraoperative Gram stain in revision total knee arthroplasty. J Bone Joint Surg Am. 2009;91(9):2124-9. Available at: Accessed April 11, 2010.
- Berbari EF, Hanssen AD, Duffy MC, et al. Risk factors for prosthetic joint infection: case-control study. Clin Infect Dis. 1998;27(5):1247-54. Available at: Accessed August 30, 2010.
- Parvizi J, Ghanem E, Menashe S, Barrack RL, Bauer TW. Periprosthetic infection: what are the diagnostic challenges? J Bone Joint Surg Am. 2006;88 Suppl 4:138-47. Available at: Accessed December 21, 2009.
- Parvizi J, Ghanem E, Sharkey P, Aggarwal A, Burnett RSJ, Barrack RL. Diagnosis of infected total knee: findings of a multicenter database. Clin Orthop Relat Res. 2008;466(11):2628-33. Available at: Accessed August 30, 2010.
- Spangehl MJ, Masri BA, O'Connell JX, Duncan CP. Prospective analysis of preoperative and intraoperative investigations for the diagnosis of infection at the sites of two hundred and two revision total hip arthroplasties. J Bone Joint Surg Am. 1999;81(5):672-83. Available at: Accessed April 11, 2010.
- Trampuz A, Piper KE, Jacobson MJ, et al. Sonication of removed hip and knee prostheses for diagnosis of infection. N Engl J Med. 2007;357(7):654-63. Available at: Accessed April 11, 2010.
- Parvizi J, Jacovides C, Zmistowski B, Jung KA. Definition of periprosthetic joint infection: is there a consensus? Clin Orthop Relat Res. 2011;469(11):3022–30.
- Bedair H, Ting N, Jacovides C, et al. The Mark Coventry Award: diagnosis of early postoperative TKA infection using synovial fluid analysis. Clin Orthop Related Res. 2010. Available at: http://www.ncbi.nlm.nih.gov.proxy1.lib.tju.edu:2048/pubmed/20585914. Accessed August 30, 2010.
- Ghanem E, Parvizi J, Burnett RSJ, et al. Cell count and differential of aspirated fluid in the diagnosis of infection at the site of total knee arthroplasty. J Bone Joint Surg Am. 2008;90(8):1637-43. Available at: Accessed August 30, 2010.
- Della Valle C, Parvizi J, Bauer TW, et al. American Academy of Orthopedic Surgeons clinical practice guideline on: the diagnosis of periprosthetic joint infections of the hip and knee. J Bone Joint Surg Am. 2011;93(14):1355-7. Available at: Accessed February 10, 2012.