Effects of Preoperative Whey Protein and Exercise Support on Recovery After Total Hip Arthroplasty

Background:

Hip osteoarthritis (HOA) is a common degenerative disease in older adults that leads to pain, deformity, and functional loss, thereby reducing quality of life. Muscle atrophy, neuromuscular dysfunction, and pain are frequently observed in the affected limb, resulting in decreased muscle strength. Gait analyses have shown reduced hip range of motion (ROM), decreased walking speed, and diminished hip flexion and abduction moments.

Total hip arthroplasty (THA), widely used in the treatment of HOA, is also performed for femoral fractures, arthritis, developmental hip dysplasia, and osteonecrosis. Although THA is an effective surgical method, delayed wound healing, infection risk, muscle weakness, and mobilization limitations remain important postoperative challenges. With postoperative pain reduction, hip function and quality of life improve significantly. However, diminished proprioception may cause balance problems, increasing the risk of falls.

Exercise therapy plays a key role in postoperative rehabilitation after THA. Physiotherapists provide gait training, ROM exercises, and balance activities. Exercise therapy reduces pain and increases physical activity levels. Systematic reviews have demonstrated the positive effects of exercise on muscle strength and gait performance following THA.

Nevertheless, delayed wound healing, infection, increased morbidity and mortality, and prolonged hospitalization may still occur after THA. In this context, preoperative nutritional support plays a critical role in improving patient outcomes. Protein-based supplements can support muscle protein synthesis and accelerate recovery. Increased protein intake helps prevent muscle breakdown and supports recovery. Thus, selecting an appropriate nutritional and exercise strategy is essential in the postoperative management of orthopedic patients.

Whey protein (WP) is a protein source rich in branched-chain amino acids (BCAAs) and essential amino acids, with high bioavailability and easy digestibility. WP has been shown to stimulate muscle protein synthesis, enhance recovery, and reduce postoperative infection risk.

In Turkey, the surgical needs of the elderly population are steadily increasing, and THA procedures are becoming a major healthcare requirement, especially in older age groups. While the separate effects of exercise and protein supplementation on postoperative outcomes have been demonstrated, there is no study in Turkey evaluating the combined impact of these two interventions when applied in the preoperative period.

This project aims to be the first randomized controlled trial in elderly THA patients to investigate the effects of oral whey protein supplementation combined with a preoperative exercise program on metabolic markers, early mobilization, and length of hospital stay. Both interventions are safe, cost-effective, and easy to apply, and they allow elderly patients to continue daily activities without additional effort or time burden. This project is expected to contribute significantly to the literature by offering an innovative approach in postoperative THA management and by generating scientific evidence on the interaction between nutrition, exercise, and surgical outcomes. The study will be conducted under the supervision of an experienced orthopedic surgeon, with methodological and practical support from clinical dietitians and physiotherapists. The intervention design, data collection, and analysis procedures are planned in accordance with the literature and scientific standards.