Periarticular Injection Reduces Opioid Use After Knee Infection Surgery

A retrospective study of 309 patients shows local anesthetic infiltration lowers pain scores without increasing 12-month reinfection risk.

For Doctors in a Hurry

Clinicians often avoid periarticular injections during knee infection surgery due to concerns regarding potential bacterial spread.
The researchers retrospectively reviewed 309 patients undergoing surgical treatment for knee periprosthetic joint infection between 2015 and 2023.
Patients receiving injections showed lower opioid consumption at 24 hours (90.2 versus 130.4 morphine milligram equivalents, P = 0.0036).
The study concludes that periarticular injections reduce early postoperative pain without increasing the one-year reinfection rate (5.0% versus 8.0%).
Physicians may consider these injections as a safe adjunct to improve pain management and reduce opioid exposure after surgery.

Analgesic Strategies in the Management of Periprosthetic Joint Infection

Periprosthetic joint infection remains one of the most debilitating complications following total joint arthroplasty, often necessitating complex surgical interventions that result in significant postoperative pain [1]. While multimodal analgesic strategies such as periarticular injection are standard in primary total hip and knee replacements to reduce opioid consumption, their use in infected cases has been historically limited by concerns regarding the potential spread of pathogens [2, 3]. Recent advancements in regional delivery, including intraosseous administration (the injection of medications directly into the bone marrow space to achieve rapid systemic or local effects) and specialized nerve blocks, highlight the ongoing effort to optimize local drug concentrations while minimizing systemic side effects [1, 4]. However, the clinical dilemma persists regarding whether local infiltration techniques can be safely utilized during debridement or revision surgery for active infection [5, 6]. A recent retrospective analysis now provides evidence regarding the safety profile and analgesic efficacy of this approach in patients undergoing surgical treatment for knee periprosthetic joint infection.

Evaluating Safety and Efficacy in a Retrospective Cohort

Periprosthetic joint infection (PJI) represents a serious complication following total knee arthroplasty (TKA), frequently necessitating extensive surgical intervention and complex revision procedures that involve the removal of infected tissue and hardware. While intraoperative periarticular injection (PAI), which involves the infiltration of local anesthetic into the soft tissues surrounding the joint during surgery, is a standard component of multimodal analgesia in primary TKA, its application in the setting of infection has been restricted. Clinicians have historically avoided PAI in infection-related procedures due to concerns that the injection process might inadvertently spread pathogens within the surgical site or seed bacteria into deeper tissue planes. To address this clinical uncertainty, researchers conducted a retrospective review of 309 patients who underwent surgical treatment for knee PJI between 2015 and 2023, providing a robust dataset for evaluating the risks of this analgesic technique.

The study population was divided into two cohorts to compare outcomes based on the use of local infiltration. The study group consisted of 121 patients who received intraoperative PAI, while a control group of 188 patients did not receive the injection. The researchers evaluated the efficacy of the intervention by recording patient-reported pain scores and total opioid consumption, measured in morphine milligram equivalents (MME) (a standardized value used to compare the potency of different opioid medications by converting them to a single unit of measure), at 24, 48, and 72 hours following the procedure. To ensure the safety of the technique, the primary safety endpoint was the rate of reinfection assessed at one year post-surgery, a critical timeframe for determining the success of the initial infection management.

Impact on Opioid Consumption and Patient-Reported Pain

The researchers found that intraoperative PAI during surgical treatment for knee PJI reduced early postoperative opioid requirements and patient-reported pain levels without compromising clinical safety. A primary finding of the study was the significant reduction in narcotic use during the immediate recovery phase, which is often the most challenging period for patient comfort. Specifically, patients who received PAI required significantly less average morphine milligram equivalents (MME) in the first 24 hours after surgery compared to the non-PAI group (90.2 versus 130.4 MME, P = 0.0036). This reduction in opioid consumption is clinically significant for patients undergoing extensive revision procedures, as it may help mitigate the risk of opioid-related adverse events, such as respiratory depression, postoperative ileus (a temporary lack of muscle contractions in the intestines), or cognitive impairment, during the critical first day of recovery.

In addition to lower medication requirements, the cohort receiving local infiltration demonstrated improved subjective pain control throughout the initial postoperative period. The PAI group reported decreased pain scores compared to the non-PAI group at the 24-hour mark (5.53 versus 5.71, P < 0.001). This analgesic benefit extended into the second postoperative day, as the PAI group reported decreased pain scores compared to the non-PAI group at the 48-hour mark (5.35 versus 5.64, P = 0.042). These data suggest that the local anesthetic effect provides a more stable pain profile during the window when patients are typically expected to begin early mobilization, which is essential for preventing venous thromboembolism and stiffness.

For the practicing clinician, these findings indicate that the inclusion of periarticular local anesthetic does not merely supplement systemic analgesia but actively displaces the need for higher-dose narcotics. By achieving lower patient-reported pain levels and reduced early postoperative opioid requirements, surgeons can potentially improve the overall patient experience and streamline recovery protocols. These results provide a quantitative basis for utilizing PAI as an effective adjunct in the management of periprosthetic joint infection, balancing the necessity of aggressive surgical intervention with the clinical imperative to minimize opioid exposure in a high-risk population.

Addressing Concerns Regarding Reinfection Risk

The primary clinical hesitation regarding the use of local anesthetic infiltration in the setting of periprosthetic joint infection is the theoretical risk of spreading pathogens or compromising the surgical site's environment. However, the data from this study suggest these concerns may be unfounded. The researchers found that intraoperative periarticular injection did not increase the risk of reinfection in this population, providing a critical safety signal for surgeons managing these complex cases. By utilizing local infiltration, clinicians can address acute postoperative pain without evidence of detrimental effects on the long-term success of the infection clearance, which is the ultimate goal of PJI surgery.

When evaluating the primary safety endpoint, there were no significant differences in reinfection rates at 12 months, with 5.0% in the periarticular injection group versus 8.0% in the non-injection group (P = 0.30). This lack of statistical difference in a high-risk cohort indicates that the mechanical administration of the anesthetic does not facilitate the persistence or recurrence of the infection. For the practicing orthopedic surgeon, these findings establish periarticular injection as a viable and safe adjunct for pain management during the surgical treatment of knee periprosthetic joint infection, allowing for the optimization of patient comfort without compromising the 12-month clinical outcome. This evidence supports a shift toward more aggressive multimodal pain management even in the presence of active infection.

Study Info

Periarticular Injection for Pain Control after Surgical Treatment of Knee Periprosthetic Joint Infection

George A. Shultz, Alicia M. Williams, Levent A. Ozdemir, Eric R. Siegel, et al.

Journal The Journal of Arthroplasty

Published April 01, 2026