The Effect of Proprioceptive Neuromuscular Facilitation and Tendon Vibration After Total Knee Arthroplasty

The Effect of Proprioceptive Neuromuscular Facilitation and Tendon Vibration After Total Knee Arthroplasty

The Effect of Proprioceptive Neuromuscular Facilitation and Tendon Vibration After Total Knee Arthroplasty: A Randomized Clinical Trial

Knee osteoarthritis is a degenerative joint disease characterized by destruction and progressive loss of articular cartilage. In an advanced stage of the disease, the patient undergoes a total replacement of the knee joint with an artificial joint (total arthroplasty). The aim of this clinical study is to investigate the effect of combining a therapeutic exercise program based on Proprioceptive Neuromuscular Facilitation (PNF) and tendon vibration in older adult patients after total knee arthroplasty (TKA). Ninety (90) adults over 65 years of age who will undergo TKA due to knee osteoarthritis will be divided into three groups of 30 people each (two intervention and one control). The participants of the first group will follow a therapeutic exercise protocol based on the PNF technique for six weeks. The participants of the second intervention group will follow the same therapeutic exercise program based on PNF and at the same time tendon vibration will be applied to the Achilles tendon for the same period. Finally, the participants of the third group (control group) will follow the conventional physical therapy postoperative treatment. The subjective perception of pain with the Numeric Pain Rating Scale (NPRS), Active Range of Motion (AROM) of knee flexion with a goniometer, functional ability with the Knee Injury Outcome Questionnaire and osteoarthritis (Knee Injury and Osteoarthritis Outcome Score, KOOS), quality of life with the Western Ontario and McMaster Universities Arthritis Index (WOMAC), balance confidence with the balance confidence (CONFbal) scale, dynamic balance with the Time Up and Go (TUG) tests and Berg Balance Scale (BBS), displacement of the center of mass by static posturography, and knee proprioception by calculating joint position sense with an isokinetic dynamometer will be assessed at the beginning of the intervention , at week 3, week 6 and six months after the end of the intervention. For the statistical analysis of the results, a two-factor analysis of variance with repeated measurements will be applied, while the statistical significance index will be set at p < .05.

Background: Knee osteoarthritis is a degenerative joint disease characterized by destruction and progressive loss of articular cartilage. It occurs more often in older adults and is accompanied by pain, stiffness and swelling of the knee joint, difficulty in walking, and a decrease in the functioning of the patient. In an advanced stage of the disease, the patient undergoes a total replacement of the knee joint with an artificial joint (total arthroplasty). Aim: The aim of this clinical study is to investigate the effect of combining a therapeutic exercise program based on Proprioceptive Neuromuscular Facilitation (PNF) and tendon vibration in older adult patients after total knee arthroplasty (TKA). Method: Ninety (90) adults over 65 years of age who will undergo TKA due to knee osteoarthritis will be divided into three groups of 30 people each (two intervention and one control). The participants of the first group will follow a therapeutic exercise protocol based on the PNF technique for six weeks. The participants of the second intervention group will follow the same therapeutic exercise program based on PNF and at the same time tendon vibration will be applied to the Achilles tendon for the same period. Finally, the participants of the third group (control group) will follow the conventional physical therapy postoperative treatment. The subjective perception of pain with the Numeric Pain Rating Scale (NPRS), Active Range of Motion (AROM) of knee flexion with a goniometer, functional ability with the Knee Injury Outcome Questionnaire and osteoarthritis (Knee Injury and Osteoarthritis Outcome Score, KOOS), quality of life with the Western Ontario and McMaster Universities Arthritis Index (WOMAC), balance confidence with the balance confidence (CONFbal) scale, dynamic balance with the Time Up and Go (TUG) tests and Berg Balance Scale (BBS), displacement of the center of mass by static posturography, and knee proprioception by calculating joint position sense with an isokinetic dynamometer will be assessed at the beginning of the intervention , at week 3, week 6 and six months after the end of the intervention. For the statistical analysis of the results, a two-way analysis of variance with repeated measurements will be applied, while the level of significance will be set at p < .05. Expected results: It is known that older adults with TKA present deficits in balance and knee proprioception due to the long-term functional limitations caused by the symptoms of the disease (difficutly - pain during standing and movement, impaired gait patterns). These deficits persist even after TKA, making older adutls more vulnerable to falls and future injuries. The investigators believe that the effectiveness of an exercise program based on PNF in relation to conventional treatment in Greece has not been sufficiently studied and that the PNF program that will be applied in this research will be more effective than conventional physical therapy. They also believe that the inclusion of tendon vibration in the PNF-based therapeutic exercise program will further increase the balance and proprioceptive ability of older adults while at the same time it may accelerate their recovery process.

Knee Osteoarthritis, Total knee arthroplasty, Proprioceptive Neuromuscular Facilitation, Focal Tendon Vibration, Physiotherapy

Ninety (90) adults over 65 years of age who will undergo TKA due to knee osteoarthritis will be divided into three groups of 30 people each (two intervention and one control). The participants of the first group will follow a therapeutic exercise protocol based on the PNF technique for six weeks. The participants of the second intervention group will follow the same therapeutic exercise program based on PNF and at the same time tendon vibration will be applied to the quadriceps tendon for the same period. Finally, the participants of the third group (control group) will follow the conventional physical therapy postoperative treatment. All interventions will have a duration of six weeks with a follow-up six months after the end of the intervention.

Participants allocated to this group will receive 18 sessions of therapeutic exercise program based on the PNF concept (Bello et al. 2011).

Participants allocated to this group will receive the same PNF protocol with Group 1 in combination with the application of tendon vibration.

The protocol will be individualized and will last 45 minutes. The following techniques will be applied: Application of the "hold - relax" technique to increase the range of motion of knee flexion. Rhythmic initiation with the application of diagonal trunk and lower limb shapes. Application of stabilizing reversals from a sitting and standing position. Application of dynamic reversals from a standing position. Rhythmic stabilization. Combination of isotonics. Gait retraining.

Participants in this group will be given the same exercise program as Group 1 combined with the application of tendon vibration. Tendon vibration will be applied on both quadriceps' tendons in three weekly sessions (not on the same day as the exercise program). To implement the protocol, 100 Hz frequency mechanical stimulation will be applied.

Participants in this group will follow a conventional six-week home physical therapy program that will include: Range exercises of the knee joint and the ankle joint of the operated limb. Stretching of the muscles of the lower limbs. Walking inside and outside the house. Exercises to strengthen the muscles of the lower limbs.

This tool is an eleven-point pain scale numbered from zero to 10. The left end of the scale corresponds to zero and is marked as "No pain", whereas the right end corresponds to 10 and is marked as "Maximum pain". Consequently, a higher value indicates more intense pain (Childs et al, 2005). The examinee is asked to choose an integer that best reflects the intensity of their pain. The NPRS is widely used to measure pain in both clinical practice and research, showing high test-retest reliability and high conceptual construct validity.

Active range of knee flexion will be assessed with a long arm goniometer. The measurement will be performed with the subject supine on the examination bed based on the instructions by Hancock et al. (2018), according to whom, measurement with a long arm goniometer shows very high reliability. Three consecutive bends will be requested from the examinee and the highest measured value will be recorded.

3. Changes in functional capacity with the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire

The KOOS questionnaire is a self-report questionnaire for the assessment of functional limitations related to knee injuries or osteoarthritis (Roos et al. 1998). It is used both in research to assess functional ability and in clinical practice. It includes 42 questions which are divided into 5 subscales: knee pain, other knee symptoms, functional limitations, ability to participate in sports or leisure activities and quality of life. A five-point Likert scale from 0 (No problems) to 4 (Extreme problems) is used to score the questionnaire. The final score results from the sum of the five separate subcategories. A higher score implies greater functional limitations. In our research, the Greek version of the questionnaire will be used, which according to Moutzouri et al. (2003) shows excellent internal consistency and good reliability from one measurement to another (test-retest reliability).

The WOMAC index is widely used in the assessment of the quality of life of people with osteoarthritis of the hip and knee (Salafi et al. 2005). It is a self-report questionnaire consisting of 24 questions classified into three subscales: Pain, knee joint stiffness and functional ability in everyday skills.Test questions are scored on a scale of 0 to 4. Scores for each subscale are summed, with a possible score range of 0-20 for pain, 0-8 for stiffness, and 0-68 for functional ability. A sum of the scores for all three subscales gives a total WOMAC score. The higher the score, the less functional the joint.The internal consistency of the subcategories of the Greek WOMAC version ranges from high (0.804) to excellent (0.956), while the intra-class correlation coefficients for test-retest reliability have been characterized as excellent (ranging between 0.91 - 0.95) (Papathanasiou et al. 2015).

The CONFbal questionnaire is a tool that assesses the self-esteem of an elderly person associated with the risk of falling. It consists of a 10-item scale, which are summed to give an index of balance confidence. The score ranges from 10 to 30. A higher score indicates lower balance confidence. Τhe questionnaire demonstrates excellent internal consistency and excellent test-retest reliability. The Greek version of the questionnaire CONFbal - GREEK (Billis, et al., 2011) will be used in this study.

It is a simple test used to assess a person's mobility. It requires both static and dynamic balance and is a valid and reliable indicator of the functional ability of an individual (Podsiadlo & Richardson, 1991). The participant starts in a seated position. They then stand up following the instructions of the therapist, walk three meters, turn around, walk back to the chair and sit down. The examiner tracks time using a stopwatch. Time is calculated in seconds. A higher score indicates lower functional ability of the participant. The TUG shows high reliability indices in older adults both in measurements by different examiners and in measurements by the same examiner at different times (Cameron and Monroe, 2007).

The Berg Balance Scale is a tool proposed by Berg (Berg et al., 1989; Berg et al., 1992) for assessing balance in the elderly. The test involves the execution of 14 tests of gradual increasing difficulty where in each one, the subject is asked to maintain a given position for a specific time or conduct specific tasks. Each of the 14 tests on the list is graded according to the balancing ability of the examinee from 0 to 4 points (with 0 indicating low balance ability, while 4 indicates high balance ability). According to Berg et al. (1992), a score of 56 indicates functional balance, whereas a score lower than 45 indicates notable balance deficits that have been related to increased fall risk. Studies have shown high intra-rater and inter-rater reliability in the elderly populations with intraclass correlation (ICC) ranging from .98 to .88 (Berg et al. 1992) and high content validity (Telenius et al., 2015).

Changes of COM displacement will be recorded through static postulography based of the protocol of Wanderley et al. (2011). To perform this test, participants will be asked to remain barefoot and static for one minute while standing at ease on the force platform with feet shoulder-width apart and gazing at a target placed at 2m. Three attempts will be performed with one-minute intervals in-between. The same procedure will be repeated with eyes closed. Three types of posturographic variables will be analyzed: center of pressure (CoP), sway area, which refers to CoP sway with a 95% ellipse area; CoP sway velocity; and CoP sway frequency (80% power spectrum). All variables will be analyzed in the anterior-posterior and medial-lateral directions. The mean value for the 3 attempts for each variable will be calculated and will be used for analysis.

Joint position sense will be calculated using an isokinetic dynamometer according to the protocol of Ma et al. (2022). The measurement will be performed according to Borsa et al. (1997) at three angles: 30°, 60° and 90° with the knee moving from full extension (180°) to flexion. During the measurement, the examinee will be asked through a switch in their hand to stop the movement at the specific angles. Each pause of the system via the switch at the reference angles will be noted and the difference in degrees of the recorded angle from the actual angle will be used as the variable.

Inclusion Criteria: Age over 65 years Unilateral primary total knee arthroplasty Body mass index less than 30 Active knee flexion range of motion of at least 90° two weeks after surgery Written consent to participate in the research Exclusion Criteria: Infection of the operated knee after surgery Neurodegenerative disease (e.g., Parkinson's) Cognitive deficits - dementia (Mini Mental State Exam Test score < 23)