Copyright © 2009 by The Journal of Bone and Joint Surgery, Inc.
Commentary & Perspective
Commentary & Perspective by
John C. Clohisy, MD*,
Washington University School of Medicine, St. Louis, Missouri
Posted January 2009
Fortunately, major complications do not occur frequently
following primary total knee replacement, yet, when encountered, they pose substantial
challenges to both the surgeon and the patient. Deep infection and some of its
more ominous aftermaths (resection arthroplasty, muscle-flap coverage, or even amputation)
are complications that are associated with increased cost, patient morbidity,
and suboptimal clinical results. Early postoperative knee-wound problems are
thought to be associated with an increase in the risk of major complications
and are particularly concerning because of the proximity of the prosthetic
joint and the relatively thin soft-tissue envelope. Yet the risk factors and prevalence
of early wound-healing problems have not been definitively established in the
literature. In addition, prognosis and treatment-result data with regard to
early wound complications are lacking.
In this study, the authors performed a retrospective review
of a large series of primary total knee arthroplasties performed at a tertiary
care institution. They screened more than 17,000 cases of primary total knee
arthroplasty and identified fifty-nine knees that required surgical treatment
of a wound complication within thirty days after the index total knee replacement,
a prevalence of 0.33%. In this subgroup of patients, the two-year cumulative probability
of additional major surgery and deep infection was 5.3% and 6.0%, respectively.
These probabilities were significantly higher (p < 0.001) than those for patients
who did not require surgical treatment for early wound complications.
In the second aspect of the study, a case-control analysis demonstrated
that a diagnosis of diabetes mellitus was significantly associated with the
development of early wound complications that required surgical intervention (p
= 0.01). Other factors that showed a suggestive, but not significant,
association with the development of early wound complications included a body
mass index of >30, previous open knee surgery, and a history of peripheral vascular
disease. These risk factors also have been associated with postsurgical
complications by other investigators1,2. Collectively, these data
are important and establish that while additional surgery for early wound
complications is uncommon, it is associated with a significantly increased risk
of deep implant infection and/or subsequent major surgery. These data provide
improved information for the counseling of patients with early wound
complications. Such patients should be informed of the increased risk of major
complications despite timely intervention for wound management.
In general, the limitations of the study were well-discussed
by the authors. Additionally, because these arthroplasties were performed at a
high-volume total joint arthroplasty center where the prevalence of wound
complications may be lower than that at lower-volume centers3,4, the
findings may not be generalizable to all hospital settings. Also, the decision
to treat a wound surgically was not reached according to any established
protocol; rather, it was made independently by the treating surgeon. As
discussed by the authors, there was also a group of patients with early wound
complications that were not treated surgically; the outcome data on these
patients are not available. Because of this shortcoming in the study design,
the authors were unable to establish strict criteria for returning a patient to
surgery. Therefore, uncertainty remains regarding specific indications for
returning to surgery to treat early wound complications. This decision must be
made on a case-by-case basis. Most arthroplasty surgeons would agree that a return
to surgery should be considered for a draining or massive wound hematoma, substantial
wound dehiscence, prolonged wound drainage, or deep wound infection. At our
center, we favor more aggressive surgical treatment of early wound
complications in an attempt to reduce the potential for the catastrophic
complications of infection and subsequent major surgery. The authors also emphasize
that establishing whether the knee is infected or not is a very important part
of the initial workup for wound complications. An early diagnosis of infection
may help preserve a good outcome.
Overall, this study provides important data and highlights
the importance of effectively managing early wound complications associated
with primary total knee arthroplasty. During the index surgery, care should be
taken to avoid soft-tissue damage about the knee and to optimize the
environment for primary wound-healing. Postoperatively, the surgeon should be
very diligent about managing early wound complications in a timely fashion, as
this may decrease the risk of subsequent deep joint infection or the need for subsequent
major surgery.
*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity.
References
1. Jain NB, Guller U, Pietrobon R, Bond TK, Higgins LD. Comorbidities increase complication rates in patients having arthroplasty. Clin Orthop Relat Res. 2005;435:232-8.
2. Winiarsky R., Barth P, Lotke P. Total knee arthroplasty in morbidly obese patients. J Bone Joint Surg Am. 1998;80:1770-4.
3. Katz JN, Barrett J, Mahomed NN, Baron JA, Wright RJ, Losina E. Association between hospital and surgeon procedure volume and the outcomes of total knee replacement. J Bone Joint Surg Am. 2004;86:1909-16.
4. Katz JN, Losina E, Barrett J, Phillips CB, Mahomed NN, Lew RA, Guadagnoli E, Harris WH, Poss R, Baron JA. Association between hospital and surgeon procedure volume and outcomes of total hip replacement in the United States Medicare population. J Bone Joint Surg Am. 2001;83:1622-9.
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