Outcomes Following Tourniquet and Non-Tourniquet Assisted Total Knee Arthroplasty

The overall goal of this study is to determine the effects of intraoperative tourniquet use during total knee arthroplasty (TKA), compared to TKA without the use of a tourniquet (NOTQT), for strength and functional recovery following simultaneous bilateral TKA. During the procedure, each patient will receive tourniquet-assisted TKA (TQT) on one lower extremity while the contralateral lower extremity undergoes TKA without the use of a tourniquet (NOTQT), except for briefly during component cementation. Tourniquets are commonly used in TKA to improve visualization of the surgical field and limit blood loss. However, studies suggest that tourniquet use may be associated with higher rates of medical complications and poor functional outcomes, including increased swelling, decreased muscle strength and altered neuromuscular activity. We will measure strength, voluntary muscle activation, and other functional outcomes for each lower extremity at 4 time points (preop; inpatient (24-72 hrs after surgery); 3 weeks; and 3 months following TKA). We hypothesize that lower extremities in the NOTQT group will demonstrate improved strength and performance when compared to lower extremities in the TQT group.

All lower extremities will be exsanguinated by elevation for 2 minutes. For lower extremities in the tourniquet group (TQT), a pneumatic tourniquet will be inflated according to standard practice (>200 mmHg). For the NOTQT group, the tourniquet will only be inflated during component cementation. In both groups, tourniquet will be deflated after bone cement has set. In both groups, electrocautery will be used as needed throughout the procedure.

All lower extremities will be exsanguinated by elevation for 2 minutes. For lower extremities in the tourniquet group (TQT), a pneumatic tourniquet will be inflated according to standard practice (>200 mmHg). For the NOTQT group, the tourniquet will only be inflated during component cementation. In both groups, tourniquet will be deflated after bone cement has set. In both groups, electrocautery will be used as needed throughout the procedure.

NOTQT will result in greater quadriceps muscle strength (primary outcome) after TKA, compared to TQT group. Benefits will be apparent at 48-72 hrs and 3 weeks (primary endpoint), and persist though 3 months following TKA

Patients will be asked to perform a test of unilateral balance ability. Patients will place both hands on their hips before assuming a single limb stance. Patients will attempt to hold this position for a maximum time of 60 seconds, although timing will stop if patients ever place both feet on the ground, if the non-stance leg braces against the stance leg to control balance, or if hands are removed from the hips to regain balance.

Knee flexion and extension range of motion (ROM) will be quantified using a standard long-arm goniometer with the patient lying in supine. Knee flexion ROM will be defined as the angle of maximal active bending of the knee. Knee extension ROM will be the angle of maximal straightening while the patient's heel is propped on a 10cm wooden block. If hyperextension is achieved, then the degrees of extension beyond zero will be recorded as a negative value.

Radiographic examination will be used to provide preliminary data on rates of fracture and tibiofemoral joint malalignment specific to the use of tourniquet during surgery.

Inclusion Criteria: undergoing primary, simultaneous bilateral knee arthroplasty for osteoarthritis Exclusion Criteria: no neurological, vascular or cardiac problems that limit function or any unstable orthopaedic conditions that limit functional performance