Vibration Applications After Total Knee Arthroplasty in Osteopenic Women

Osteoarthritis (OA) is a chronic degenerative disease characterized by the destruction of articular cartilage, leading to functional impairment of surrounding bone and soft tissues. It is a major global public health problem, with the knee joint being the most commonly affected site. Treatment modalities include exercise, diet, oral non-steroidal anti-inflammatory drugs (NSAIDs), intra-articular injections, and total knee arthroplasty (TKA). TKA is indicated in cases of severe pain, functional loss, deformity, and limited range of motion when conservative methods are no longer effective. However, some patients may continue to experience deformity and functional deficits after surgery. Postoperative quadriceps weakness and decreased functional capacity can negatively affect patient prognosis. Following TKA, bone mineral density (BMD) tends to decrease during the first three months. The reduction in BMD and the increase in bone resorption may elevate the risk of implant loosening or periprosthetic fracture. Bone turnover markers (BTMs), which are enzymes or degradation products released into circulation by bone cells, reflect bone remodeling processes and can help identify increased fracture risk. A significant proportion of TKA candidates are osteopenic. Since osteopenic individuals make up a larger segment of the population, most fragility fractures actually occur in individuals with osteopenia rather than osteoporosis. Therefore, BMD levels and the presence of osteopenia or osteoporosis should be taken into account in patients undergoing TKA. To preserve both bone quality and muscle mass, early rehabilitation and progressive weight-bearing on the operated limb are considered essential. These strategies may improve both BMD and BTMs. Whole-body vibration (WBV) therapy has been suggested as an effective and safe method to increase mechanical loading on the bones. WBV can be applied in a static standing position on a vibration platform or combined with simultaneous exercise. Given the limited availability of targeted strategies to improve bone remodeling and BTMs after TKA, and the lack of clarity regarding the optimal WBV protocol, this study aims to investigate the effects of different vibration applications on bone turnover markers, functionality, muscle strength, pain intensity, pressure pain threshold, range of motion, proprioception, edema, and muscle biomechanical properties in osteopenic women following TKA. Participants will be randomly assigned to one of three groups: WBV only, WBV combined with exercise (WBV-E), or control. All groups will receive traditional rehabilitation three times per week for four weeks after surgery. WBV interventions will begin at the end of the fourth postoperative week, once patients are deemed ready. While WBV groups will receive additional vibration therapy, the control group will continue traditional rehabilitation alone. Outcomes will be evaluated using bone turnover markers, the Timed Up and Go (TUG) test, the 30-Second Chair Stand Test, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), measurements of muscle biomechanical properties and strength, pain intensity and pressure pain threshold, joint range of motion, proprioception, and edema.