Outcome measures
MVIC, Pain, pain
SECONDARY, CONTRACTION
The primary outcome was quadriceps muscle strength preservation. It was measured as the difference in quadriceps strength preoperatively and 6 h after surgery, using the maximum voluntary isometric contraction (MVIC). The MVIC was assessed by a Physical Medicine and Rehabilitation specialist at the preadmission consult and at 6, 24 and 48 h postoperatively. A handheld dynamometer (HHD) was used (MicroFET2; Hoggan Health Industries Inc., UT, USA) [The secondary outcomes were pain control and functionality. Pain was assessed preoperatively and at 6, 24 and 48 h after surgery. Pain measurement was obtained at rest and during 45° passive flexion of the knee on a 0 (no pain) to 100 (pain as bad as it can be) visual analogue scale (VAS). Furthermore, cumulative opioid consumption was calculated at these time points using units of morphine milligram equivalents (MME) to analyze supplementary pain relief requirement. Functional tests were also measured preoperatively and at 6, 24 and 48 h postoperatively using the Timed Up and Go test (TUG), 30-secs-Chair-Stand-Test (30′ CST), 10-Point-Mobility-Scale (10-PMS), Daniels test and passive/active Range of Motion (ROM). Length of hospital stay (LOS) was measured from the surgery day until patient discharge.