Swelling Management after Total Knee Arthroplasty

PROJECT SUMMARY
Although total knee arthroplasty (TKA) is effective at reducing pain from end-stage osteoarthritis (OA), it is
an acute trauma to the joint which exacerbates the underlying weakness and disability common with OA,
leading to long-term atrophy and further disability. Attenuation of this acute loss of strength and function can
lead to improved long-term outcomes. Key to attenuating this acute loss is effectively managing postoperative
knee swelling. Knee swelling after TKA is profound and is theorized to be a major driver of this acute strength
and functional loss. This early postoperative strength loss is driven by a deficit in voluntary activation that
acutely limits rehabilitation potential and leads to long-term atrophy and disability. Traditional interventions
such as elastic compression stockings (e.g., thromboembolism-deterrent [TED] hose) have minimal
effectiveness in reducing swelling after TKA. We have demonstrated in a preliminary study that an inelastic,
adjustable compression garment can decrease early postoperative swelling by 50%. However, there is a need
to formally evaluate the preliminary effects of this garment on all outcomes to inform sample size calculations
for a larger trial. Additionally, as a majority of research to date on quadriceps activation and swelling has relied
on laboratory induced swelling, this trial will be uniquely positioned to explore in-vivo mechanistic relationships
between changes in swelling and quadriceps activation. Therefore, we propose a randomized controlled study
of 58 older adult participants undergoing TKA to determine if an inelastic adjustable compression garment
(INCOM) improves postoperative swelling more than elastic TED hose (CONTROL). Both groups will wear the
assigned garments for the first 3 weeks after TKA and participate in a standardized rehabilitation program after
TKA. Outcomes will be assessed preoperatively and postoperatively at weeks 1, 3 (end of garment use),12
and 26. This study will enable us to determine (AIM 1) if INCOM results in improved surgical limb swelling
control after TKA (primary outcome) compared to CONTROL and (AIM 2) to explore the preliminary efficacy of
INCOM on the outcomes of quadriceps strength, pain, range of motion, physical function, and patient reported
outcomes after TKA compared to CONTROL. Additionally, we will explore (EXPLORATORY AIM) the
mediating role of swelling on outcomes after TKA. This study has high potential to prevent acute strength and
functional losses in the short-term and improve long-term health of the millions of older adults who will undergo
TKA annually. This study will uniquely provide insights into 1) causal relationships between swelling and
strength/functional outcomes and 2) mechanisms for quadriceps activation deficits. Study findings will also
provide insights into the management of numerous other patient populations with significant quadriceps
activation deficits (knee OA) or extremity swelling (post-surgical or trauma).

Grant Number: 5R21AR082101-03
NIH Institute/Center: NIH
Principal Investigator: Michael Bade