Niv Marom, MD , Milan Kapadia, BS, Joseph T. Nguyen, MPH , Brittany Ammerman, MBS, Isabel Wolfe, BS, Kristin C. Halvorsen, BS, Andy O. Miller, MD, Michael W. Henry, MD , Barry D. Brause, MD, Jo A. Hannafin, MD, Robert G. Marx, MD, and Anil S. Ranawat, MD
doi: https://doi.org/10.1177/03635465221078311

Summary by Carlo Coladonato, MS

Septic arthritis following anterior cruciate ligament reconstruction is a rare complication with reports ranging from 0.12-1%.^1–3 Despite its low reported incidence, the frequency of ACLR indicates that a large number of patients are affected. While there have been ample attempts to investigate factors that increase the risk for infection, the relatively low incidence has led to a paucity of conclusive evidence within the orthopaedic literature.

The purpose of this study was therefore to evaluate the association between an infection
after ACLR and potential risk factors in a large single-center cohort of patients who had
undergone ACLR. A total of 11,451 ACLR cases were identified at a single institution between
January 2010 and December 2018. All patients confirmed to have deep tissue infection as
defined by the National Healthcare Safety Network/Center for Disease Control and Prevention
guidelines for deep tissue infections.

Overall, 0.42% of the cohort obtained a post-operative infection. There were significant
differences in patient age (26.0 ± 12.0 vs 30.0 ± 12.3 years, respectively; P = .023) and graft type
(P = .005) used between infection cases and non-infection cases. There was no significant
difference found for BMI, smoking history, or Elixhauser Comorbidity Index. In the
multivariable logistic regression model for the risk of infections after ACLR, revision surgery

(OR, 3.13 [95% CI, 1.55-6.32]; P = .001), allografts compared with bone-patellar tendon-bone
(BPTB) autografts (OR, 5.27 [95% CI, 1.81-15.35]; P = .002), and hamstring tendon autografts
compared with BPTB autografts (OR, 4.39 [95% CI, 2.15-8.96]; P < .001) increased the risk of
infections. Younger age was found to be associated with an infection (OR, 1.06 [95% CI, 1.02-
1.10]), with every year increase in age associated with a decreased likelihood of infections (OR,
0.94 [95% CI, 0.91-0.98]; P = .001).

There are many factors that may influence the risk of septic arthritis following ACLR,
including graft preparation, surgical technique, graft type as well as patient characteristics. ¹ The
current study illustrates the importance of these risk factors and can enhance surgeon decision-
making. Despite the overall low incidence of infections after ACLR, the considerably lower risk
of infections with the use of BPTB autografts, compared with both hamstring tendon autografts
and allografts, is clinically relevant.
The results of the current study also suggests revision ACLR and younger age may also be
associated with a higher infection rate. ^2,4–6

References:

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