Editor’s note: The following content was originally scheduled for the AAOS Now Daily Edition, which publishes each year onsite at the AAOS Annual Meeting, but this year’s meeting in March was canceled due to COVID-19. Despite the cancellation, members can access virtual content from the Annual Meeting by visiting the Academy’s Annual Meeting Virtual Experience webpage at aaos.org/VirtualAAOS2020.

Implementation of preoperative optimization protocols for total joint arthroplasty (TJA) was associated with significant reductions in prosthetic joint infection (PJI), according to a study presented as part of the Annual Meeting Virtual Experience. Specifically, four of five protocols included in the review demonstrated significant reduction in PJI.

“Due to the rise of alternative payment models and the projected increase in number of TJAs performed in the United States, optimization of modifiable risk factors has become a priority for surgeons performing these procedures,” study presenter Nirav K. Patel, MD, FRCS, of VCU Health Department of Orthopaedics, told AAOS Now. “The existing literature suggests possible relationships between surgical outcomes and preoperative BMI, nutritional status, and glycemic control, among other modifiable risk factors. Our group felt that a review of this literature to develop an evidence-based, standardized, preoperative optimization protocol to be used by institutions prior to total hip arthroplasty (THA) or total knee arthroplasty (TKA) would be a relatively inexpensive and worthwhile endeavor in the effort to improve surgical outcomes for our patients.”

The study involved a literature search that initially returned a total of 183 articles. Of those, nine studies met inclusion criteria. They included 10,047 procedures in 9,969 patients (54 patients received bilateral TKA). A total of 5,864 cases were subject to analysis under an institution-specific protocol, and 4,183 cases were not analyzed with such protocol. Mean patient age was 65.11 years, and 60 percent of patients were male.

In addition to the finding of significant reduction in PJI for four of five protocols described by the included studies, the analysis indicated that implementation of a preoperative optimization protocol was associated with significantly shorter mean hospital length of stay (2.5 versus 3.2 days), mean cost of care, and hospital readmission rates.

Dr. Patel commented: “Our group was especially surprised at the apparent differences in rate of PJI for patients who complied with a preoperative optimization protocol. In one study of consecutive THA at a single institution, there were zero incidents of PJI in the compliant cohort compared to 2.9 percent in patients who did not meet preoperative criteria (P = 0.0038). Another study found that implementation of a combined perioperative protocol resulted in a significant (92.3 percent) reduction in PJI rate following TKA (P = 0.0016).”

Additionally, he said, “We found it interesting that some studies have reported less postoperative pain, easier participation in physical therapy, and a lower rate of discharge to an inpatient rehabilitation facility for patients who complied with an optimization protocol.”

The clinical takeaway, Dr. Patel said, is that every preoperative bundle protocol was different across the included studies, but several variables were consistently present across the varying protocols:

1. BMI (< 35–40 kg/m2)
2. hemoglobin (> 11–12 g/dL)
3. a measure of glucose control (e.g., hemoglobin A1c < 7.0–7.5 percent)
4. no tobacco use for > 30 days
5. methicillin-resistant Staphylococcus aureus colonization status
6. nutritional status as indicated by albumin (> 3.0–3.5 g/dL)

“We recommend inclusion of these parameters into preoperative optimization bundles prior to TJA,” Dr. Patel said. “Our review demonstrates that implementation of evidence-based preoperative protocols for optimization of modifiable risk factors is an inexpensive intervention that is associated with improved outcomes.”

Limitations of the study include the retrospective nature of included studies and heterogeneity of specific details of preoperative optimization protocols. Also, he said, there is not yet consensus on the optimal preoperative criteria and threshold values for frequently utilized parameters (e.g., BMI < 40 kg/m2 versus < 35 kg/m2). Additionally, “there is tremendous pressure for preoperative interventions to be clinically and cost-effective. This inherently introduces potential researcher bias toward improved outcomes following protocol implementation,” said Dr. Patel. Finally, some of the included studies acknowledged that many TJA procedures were performed despite noncompliance with proposed preoperative optimization protocols.

“Despite the limitations of this study, we feel that this review adds to the growing body of literature pointing to the success of preoperative optimization protocols in reducing postoperative complications such as PJI,” Dr. Patel said. “Furthermore, the results of this review suggest that prospective studies examining the effects of preoperative optimization protocols are needed. Specifically, the next step in refinement of preoperative patient optimization is to determine the most effective threshold values for each modifiable risk factor and to evaluate the ability of patients to safely and effectively modify their risk factors such as BMI, blood glucose control, nutritional status, and alcohol and substance use prior to TJA.”

Dr. Patel’s coauthors of “Preoperative Optimization Protocols Targeting Modifiable Risk Factors and Their Role in Total Joint Arthroplasty: A Systematic Review” are William Johns, BS; Daniel Layon, MD; Aidan Morrell; Gregory Golladay, MD; Stephen Kates, MD; and Michael Scott, MD.

Terry Stanton is the senior medical writer for AAOS Now. He can be reached at tstanton@aaos.org.