In the absence of reliable evidence, it is the opinion of this work group that patients undergo early mobilization following elective hip and knee arthroplasty. Early mobilization is of low cost, minimal risk to the patient, and consistent with current practice.

Rationale
VTED is a potentially catastrophic complication faced by all patients who undergo elective hip and knee arthroplasty. Risk factors that predispose to VTED are embodied by “Virchow’s Triad” – hypercoagulability, endothelial injury, and stasis.  Early mobilization following hip or knee arthroplasty addresses the stasis limb of Virchow’s triad; movement of the operated limb promotes regional blood flow. Mobilization should begin as soon postoperatively as possible. Practices should be in place to ensure that appropriate support are provided throughout the hospital stay to minimize the risk of falls during transfer and ambulation.

Although one moderate quality study and five low quality studies compared VTED rates based on timing of mobilization, their results are conflicting (these results are summarized in Table 35, our evaluation of their quality and applicability is shown in Table 54, and a more detailed presentation of their results is in Table 36). One study of moderate quality suggests patients mobilizing within 2-4 hours of surgery do not have lower VTED readmission rates vs. patients mobilizing the afternoon or evening of surgery. Three low quality studies suggest that there is no difference in VTED due to timing of mobilization, while two other low quality studies did find lower rates of PE or VTED readmission among patients who mobilized earlier. Based on the fact that early mobilization has minimal cost, low risk to the patient, and is consistent with current clinical practice, issuing a consensus based consensus-based recommendation is warranted.

Table 63 in Appendix XIV summarizes the reasons for excluding some of the studies we initially considered for this recommendation.