Vibration Applications After Total Knee Arthroplasty in Osteopenic Women

Istinye University

Status: Enrolling

Conditions: Osteopenia; Total Knee Arthroplasty

Treatments: Behavioral: Whole Body Vibration Therapy; Behavioral: Conventional Physiotherapy; Behavioral: Whole Body Vibration with Exercise

Study type: Interventional

Funder types: Other

Identifiers

NCT06988033

IstinyeUni-EALOGLUCIFTCI-001

Details and patient eligibility

About

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.

Enrollment: 48 estimated patients

Sex: Female

Ages: 60 to 75 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Scheduled to undergo unilateral, primary, cemented total knee arthroplasty (TKA) using a posterior cruciate ligament-sacrificing technique and medial parapatellar approach due to knee osteoarthritis
• Ability to speak and understand Turkish
• Ability to comprehend both verbal and written information
• A T-score between -2.5 and -1 (i.e., -2.5 < T-score < -1) measured by DXA in the lumbar spine, total hip, or femoral neck within the past year

Exclusion criteria

• Scheduled for revision TKA
• American Society of Anesthesiologists (ASA) physical status classification score higher than 3
• History of major surgery on the limb to be operated
• Presence of comorbid diseases such as rheumatoid arthritis or cancer
• Presence of a neurological condition causing functional impairment
• Diagnosed psychiatric disorder
• Dementia
• Disorders affecting the vestibular system
• Having undergone anesthesia for any reason within the last month
• Regular use of hypnotic or anxiolytic medications
• Hearing or vision impairment not correctable by hearing aids or glasses
• Presence of endocrine system disorders
• Secondary osteoporosis or history of osteoporotic fracture
• Metabolic bone diseases or chronic illnesses potentially affecting bone metabolism
• Use of medications known to affect bone metabolism (e.g., menopausal hormone therapy, bisphosphonates, raloxifene, calcitonin, growth hormone, parathyroid hormones, corticosteroids) within 6 months prior to the start of the study

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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48 participants in 3 patient groups

Whole Body Vibration

Experimental group

Description:

Participants in this group will receive whole body vibration (WBV) in addition to the standard postoperative rehabilitation program. WBV will be applied 3 times per week. In the first week, 1 set of 5-minute static standing WBV will be administered at a low frequency (8 Hz) and amplitude (2 mm). In subsequent weeks, progression will be applied based on participant tolerance. The frequency will increase gradually up to 30-40 Hz, and the amplitude up to 5 mm, with a total WBV duration of up to 15 minutes per session. Participants will stand upright with equal weight distribution on both feet during vibration. No concurrent exercise will be performed during WBV.

Treatment:

Behavioral: Whole Body Vibration Therapy

Whole Body Vibration with Exercise (WBV-E)

Experimental group

Description:

In this group, participants will receive whole body vibration (WBV) simultaneously with lower extremity exercises performed on a vibrating platform. After exercise training is demonstrated on a stable surface, participants will perform the exercises on the platform. WBV will be initiated with low amplitude (2 mm) for the first two weeks and increased to 5 mm by the third week depending on pain tolerance. Frequency will be maintained between 30-40 Hz. Exercises will include lunge steps, shallow squats, dynamic squats, toe raises, and ball squeezes between the knees (2-3 kg medicine ball). Vibration duration will progress from 2 minutes (3 exercises × 30 sec) to a maximum of 18 minutes (6 exercises × 60 sec × 3 sets). One-minute rest will be provided between sets and repetitions. Total session duration will vary between 45 and 70 minutes.

Treatment:

Behavioral: Whole Body Vibration with Exercise

Control

Active Comparator group

Description:

Participants in this group will receive only the standard postoperative rehabilitation program and an individualized home exercise plan. The conventional rehabilitation protocol includes exercises with rest periods of 1 minute between sets and repetitions. The average initial session duration will be approximately 45 minutes, progressing to 60-70 minutes in later sessions. No vibration intervention will be administered.

Treatment:

Behavioral: Conventional Physiotherapy