Prehabilitation in Older People Undergoing Total Hip Replacement

The (p)rehabilitation intervention program will be based on supervised whole-body RET performed 3 times/week before (2-week) and up to 12 weeks after surgery, with one day in-between sessions. Training will consist of a 10-min warm-up, followed by one warm-up and 4 sets on leg press, leg-extension and leg abductor machines. Upper body exercises (chest press, lat pulldown and horizontal row will be performed with 2 sets of each exercise. During the 2-week training before surgery, the workload will be increased from 70% (week 1) to 80% (week 2) of 1RM (10 repetitions in each set). After surgery, the workload will be increasing from 50% of 1RM to 80% from the last 6 weeks. All the participants included in the per-protocol analysis must complete at least 80% of the training sessions. We will take into consideration the mobility precautions so as not to dislocate the prosthesis (avoid hip flexion of 90 degrees and more; do not perform adduction exercises and hip rotations).

In a sub-study, the first 10 participants of the (P)rehabilitation group will be included to study the effects of 2 weeks prehabilitation on tissue protein synthesis rates. A two-week deuterium oxide (2H2O or 'heavy water') loading protocol will be conducted during the two week before THR surgery to assess diurnal rates of musculoskeletal protein synthesis. This 2H2O method enables the assessment of muscle, cartilage and bone tissue protein synthesis rates when tissue samples are collected after the 2 weeks of prehabilitation.

In a sub-study, the first 10 participants of the Usual Care group will be included to study the effects of 2 weeks prehabilitation on tissue protein synthesis rates. A two-week deuterium oxide (2H2O or 'heavy water') loading protocol will be conducted during the two week before THR surgery to assess diurnal rates of musculoskeletal protein synthesis. This 2H2O method enables the assessment of muscle, cartilage and bone tissue protein synthesis rates when tissue samples are collected after the 2 weeks of usual care.

Participants assigned to the usual care group will receive the usual therapy, medical monitoring, and educational lectures after surgery. No intervention is planned before total hip replacement surgery. The patient is hospitalized for surgery. At hospital discharge, the usual care group will start with standard rehabilitation (sessions: 1st month, 2-3x/week, 2nd month 1-2x/week and 3rd month 1x/month) based on mobility and strength exercises without using progressive RET with machines until 3 months after surgery.