Letter to the Editor on “Diagnostic Utility of Platelet Count/Lymphocyte Count Ratio and Platelet Count/Mean Platelet Volume Ratio in Periprosthetic Joint Infection After Total Knee Arthroplasty”

Abstract

care costs among the virtual PT group with similar effectiveness [6]. In addition, there are 2 retrospective studies, with similar findings to our own, but our own study is strengthened by a larger sample size and multisurgeon cohort [7,8].We agree with the comments that formal PT may still be of benefit in a subset of patients after THA and TKA. Regarding our study, we would like to first clarify that the control group was defined as patients who did not receive formal postoperative PT, not no PT at all. Patients not prescribed formal PT sessions are provided instructions and resources for a home exercise program to rehabilitate their joints. This particular distinction has an important role in the overall conclusion that can be drawn from our study. We do not aim to imply that rehabilitation is not required after TJA, but with consideration of prior studies demonstrating that selfdirected exercise programs may be appropriate for many patients, we provide evidence that opting for such a program in the appropriate patient can be an effective cost-saving measure.We do contend with the comments that costs would be, by default, higher among patients receiving PT. Although PT costs are certainly higher, we analyzed total EOC costs in our study meaning that if PT had a substantial positive impact on shortterm outcomes, then it is possible direct PT costs may be negated by savings in other postacute care resources. Although we did not demonstrate this for the entire cohort in our study, it likely may exist that this holds true for a select subset of patients, and further study is needed. We do not infer into which patients define this select subset within our own study, but several recent studies have provided guidance on that particular topic [3,4].We agree with the authors that there exist several limitations to our study because of its retrospective design. A selection bias exists in who is prescribed formal PT based on surgeon preference and patient baseline. We controlled for the significant differences in groups through multivariate analysis, but as the authors state, there are likely several confounding factors that were not collected and would further explain the differences observed. We agree that an RCT would be both ethical and ideal in assessing this topic but may not be practical. EOC costs can vary substantially, and so a large sample size may be required to achieve adequate power [9e11]. Large RCTs are both time and resource intensive. Initially investigating a clinical question through retrospective observational study can aid one in determining whether that question is worth being explored through a high-quality RCT.Our study is a valuable contribution to the literature as it builds on the recent evidence regarding the utility of formal PT after THA and TKA. In addition, it has an impact on clinical practice as it may incentivize arthroplasty surgeons to implement postsurgical protocol changes. Finally, our study encourages readers to further explore this topic in greater depth, ideally through the hig...