Vibration Applications After Total Knee Arthroplasty in Osteopenic Women

Summary

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.

Conditions

• Osteopenia
• Total Knee Arthroplasty

Interventions

BEHAVIORAL

Whole Body Vibration Therapy

Participants receive whole-body vibration therapy in a static upright position on a vibration platform (Power Plate My5). The intervention is applied 3 times per week for 8 weeks, progressively increasing frequency from 8 Hz to 40 Hz and amplitude from 2 mm to 5 mm. Each session lasts up to 15 minutes. No exercise is performed during the vibration.

BEHAVIORAL

Whole Body Vibration with Exercise

Participants perform lower extremity strengthening exercises on a vibration platform simultaneously with whole-body vibration. The protocol includes lunges, squats, heel raises, and ball squeezes. Vibration frequency ranges from 30 to 40 Hz and amplitude from 2 to 5 mm. Sessions are performed 3 times per week for 8 weeks, with duration progressing from 2 to 18 minutes depending on tolerance.

BEHAVIORAL

Conventional Physiotherapy

Participants receive standard post-total knee arthroplasty physiotherapy 3 times per week for 12 weeks, lasting 40 to 70 minutes per session. In addition, a home-based exercise program is performed 3 times daily. The program includes range of motion, strengthening, and balance exercises. No vibration therapy is applied in this group.

Sponsors & Collaborators

• Istinye University

  lead OTHER

Principal Investigators

• GÜL DENİZ YILMAZ YELVAR, ASSOCIATE PROFESSOR · Istinye University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

60 Years

Max Age

75 Years

Sex

FEMALE

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-08-01

Primary Completion

2025-11-30

Completion

2025-12-05

Countries

• Turkey (Türkiye)

Study Locations