Paper of the Week: Risk Factors for Deep Infection Following Plate Fixation of Proximal Tibial Fractures

Markus Parkkinen, MD; Rami Madanat, MD, PhD; Jan Lindahl, MD, PhD; Tatu J. Makinen, MD, PhD

Journal of Bone and Joint Surgery: Volume 98-A, Number 15, pp 1292-1297
DOI: 10.2106/JBJS.15.00894

Summary by Daniel O. Corr, BS

Deep infection is a significant concern for patients and physicians following proximal tibial fracture plate fixation, as these can often result in subsequent hardware removal and revision, an extended hospital stay, increased morbidity, and a substantial rise in the cost of care (1-3). Previous investigations of major risk factors have been inconclusive and/or contradictory, owing in part to the ambiguous criteria for defining superficial and deep infection and the fact that bacteriological confirmation is rarely included as part of the diagnostic criteria (4-6). In this study, Parkkinen et al. aim to confirm or reject previously proposed risk factors as well as explore new patient and procedure factors possibly associated with deep postoperative infection.

Between January 2004 and December 2013, 655 proximal tibial fractures in 652 patients were treated with open reduction and plate fixation at a single Level-1 trauma center. Patient clinical and surgical notes were reviewed in order to properly assess a variety of pertinent patient factors, including fracture type as defined by OTA/AO designation, necessity of an urgent 4-compartment fasciotomy, use of external fixation, use of tourniquet versus drain, etc. Surgical site infections were classified as deep when the following three criteria were met: clinical signs of infection were present, there were positive bacterial cultures, and osteosynthesis material was palpable or visible in the wound. Thirty-four patients (5.2%) met the criteria for deep surgical site infection. A control group was randomly selected from the non-infected cohort in a 1:4 ratio to number 136. The two groups were then compared against each other in order to evaluate if certain patient and procedural factors were significantly more prevalent in one group over the other.

After univariate analysis, multivariable logistic regression modeling was performed in order to control for confounding effects between variables. This analysis revealed that independent risk factors for infection included age ≥50 years [OR: 3.6 (95% CI: 1.3 to 10.1)], BMI ≥30 kg/m² [6.5 (2.2 to 18.9)], alcohol abuse [6.7 (2.4 to 19.2)], OTA/AO fracture type B compared with types A and C, use of a temporary external fixator [3.9 (1.4 to 11.1)], and necessity of urgent 4-compartment fasciotomy [4.5 (1.3 to 15.7)].

Deep infection after plate fixation of proximal tibial fractures carries substantial morbidity, as infected patients underwent a mean of 2.3 (range 1-7) additional subsequent procedures and 5 patients in the infected cohort (14.7%) went on to require above-the-knee amputation. Identifying risk factors and executing appropriate interventions could reduce the prevalence of deep surgical site infections in these patients. Limitations of the study included its retrospective nature, since prospective enrollment was deemed impractical due to the rarity of postoperative deep site infection, as well as the reliance on patient-reported chart data that may under-report factors such as smoking and alcohol abuse.

References:

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