Deep Surgical Site Infection After Knee Fracture Repair

Orthopedic surgeons should be vigilant when managing periarticular knee fracture repairs, according to a review published in JAMA Network Open.

Managing fractures around the knee is challenging. Adverse outcomes can include arthrofibrosis, compartment syndrome, and infection. Recent literature has indicated that the rate of postoperative surgical site infection (SSI) ranges from 13% to 88% for tibial plateau fractures, 3% to 45% for proximal tibia fractures, 3% to 17% for distal femur fractures, and 2% to 10% for patellar fractures. Patients with SSIs have a higher mortality rate and spend an extended time in the hospital, which results in higher medical care costs when compared with those of patients without SSIs. Therefore, orthopedic surgeons need to understand the frequency with which infectious adverse outcomes occur to manage and prevent these outcomes. However, to date, a single systemic review elucidating the overall magnitude of deep SSIs after surgical management of fractures around the knee as a whole has not been conducted. This systemic review and meta-analysis examined the prevalence of deep SSIs and the rate of septic arthritis after surgical repair of fractures around the knee.

In total, 117 studies documenting 11,432 patient outcomes were included. Eligible studies were collected from databases MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials and had to specifically report deep SSI rates and include fractures in the distal femur, patella, tibial plateau, or proximal tibia. The primary outcome was overall prevalence of deep SSI after periarticular knee fracture repair. Secondary outcomes included the overall prevalence of septic arthritis, the most commonly cultured bacteria specimens found in periarticular knee infections, and risk factors associated with deep SSI.

Among the 11,432 patients included, 653 (5.7%) patients experienced deep SSIs, with the most common SSIs seen among patients with proximal tibia fractures, which occurred in 6.4% of these patients, followed closely by patients with tibial plateau fractures (5.9%). A total of 1567 patients were included in studies on septic arthritis, and among these patients, 38 (2.4%) patients experienced septic arthritis.

From the 16 included studies that reported the results of bacterial culture from infected fracture sites, there were a total of 182 deep SSIs with bacterial culture results. The 2 most commonly reported bacteria were methicillin-resistant Staphylococcus aureus and methicillin-susceptible S aureus (67 and 53 positive cultures, respectively). Further, when risk factors associated with deep periarticular knee infection via subset analysis were assessed, results showed that being a smoker, being male, having compartment syndrome, and having an open fracture type were significantly associated development of this infection (all had a P <.001). Although not statistically significant, having diabetes may also be associated (P =.008).

However, there was a high degree of asymmetry and heterogeneity in the studies analyzed, and the quality of many studies was poor. Further, studies with higher methodologic quality had statistically significant decreases in the prevalence of deep SSI, which suggested that high-quality study designs may improve patient outcomes. Overall, the study authors concluded that, “Our hope is that by bringing attention to the poor quality of studies comprising a large sample of orthopedic traumatology research, future studies will pay greater attention to improving quality and reducing bias.”

Reference

Norris GR, Checketts JX, Scott JT, Vassar M, Norris BL, Giannoudis PV. Prevalence of deep surgical site infection after repair of periarticular knee fractures: a systemic review and meta-analysis. JAMA Network Open. 2019;2(8):e1999951.