Revision total knee arthroplasty (TKA) procedures performed secondary to periprosthetic joint infection (PJI) are associated with significant morbidity and mortality. These poor outcomes may be further complicated by the development of postoperative infection requiring aggressive antibiotic treatment. However, this antibiotic overuse may suppress patients' native bacterial flora, leading to Clostridium difficile infection (CDI). With the increased demand for primary TKAs and expected rise in revision TKA due to PJI, it is important to identify factors contributing to CDI. Therefore, we aimed to study the: 1) incidence, 2) demographics, length of stay (LOS), and total costs, and 3) risk factors and mortality associated with CDI in revision TKA patients.

The National Inpatient Sample database was queried for all individuals diagnosed with PJI and who underwent revision TKA between 2009 and 2013. Patients who developed CDI during their in-patient hospital stay were identified, yielding 83,806 patients (799 with CDI) with a mean age of 65 (S.D.=11.2). Logistic regression analysis was conducted to assess the association between hospital- and patient-specific characteristics and the development of CDI.

During the study period, the overall incidence of CDI after revision TKA was 1%. These patients were significantly older (mean age 69.05 vs. 65.52 yrs), had greater LOS (median 11 vs. 5 days), had greater costs ($30,612.93 vs. 18,873.75), and had higher in-hospital mortality (3.6 vs. 0.5%, p < 0 .001 for all) compared to those without infection. Patients with CDI were more likely to be treated in urban, not-for-profit, medium or large bed-sized hospitals located in the Northeast or Midwest (p < 0 .05 for all). Patients with underlying depression (OR 4.267, p=0.007) or fluid/electrolyte disorders (OR 3.48, p=0.001) were more likely to develop infection.

Although CDI is a rare event following revision TKA, it can have detrimental consequences. Our report demonstrates that CDI is associated with longer LOS, higher costs, and greater in-hospital mortality. With increased legislative pressure to lower healthcare expenditures, it is crucial to identify means of preventing costly complications.

Despite the widespread success of total hip arthroplasty (THA), postoperative pain management remains a concern. Opioids have classically been administered for pain relief after THA, but their side effect profile, in addition to the cognizance of the growing opioid epidemic, has incited a shift toward alternative pain modalities. Although the nonsteroidal anti-inflammatory drug (NSAID) diclofenac is a promising addition, its impact on immediate THA outcomes has not previously been investigated. Thus, in the present study, we evaluate the effects of adjunctive diclofenac on: 1) postoperative pain intensity, 2) opioid consumption, 3) discharge destination, 4) length of stay, and 5) patient satisfaction in primary THA patients.

A retrospective review was performed to identify all patients who underwent primary THA by a single surgeon between May 1 and September 31, 2017. Patients were stratified into a study group (n=25), who were treated with postoperative diclofenac in addition to the standard pain control regimen, and a control group (n=88), who did not receive adjunctive diclofenac. Repeated-measures analysis of variance (ANOVA)/analysis of covariance (ANCOVA) and chi-square/logistic regression analysis were used for continuous and categorical variables, respectively.

Patients receiving adjunctive diclofenac were more likely to be discharged home than to inpatient facilities (O.R. 4.02, p=0.049). In addition, patient satisfaction with respect to how well and how often pain was controlled (p= 0.0436 and p=0.0217, respectively) was significantly greater in the diclofenac group. Finally, patients who received diclofenac had lower opioid consumption on postoperative days one and two (−67.2 and −129 mg, respectively, p=0.001 for both).

The rapid growth of THA as an outpatient procedure has intensified the urgency of improving postoperative pain management. The present study demonstrates that THA patients receiving adjunctive diclofenac were more likely to be discharged home, had reduced opioid consumption, and experienced greater satisfaction. This will, in turn, decrease complications and total hospital costs, leading to a more cost-effective pain control regimen. In order to further investigate the optimal regimen, future studies comprising larger cohort, as well as a comparison of diclofenac to other NSAIDs, are warranted.