The Effect of PEMF for Patients With Knee OA

A Double-Blinded, Randomized-Control-Trial to Investigate the Effect of Pulsed Electromagnetic Field (PEMF) for Patients With Knee Osteoarthritis

Health care costs are increasing alarmingly, which will impose an overwhelming economic burden to an aging society like that of Hong Kong. For example, degenerative musculoskeletal disorders such as osteoarthritis (OA) present a grand challenge with its high prevalence (>40% in the elderly suffered from knee OA). OA is a debilitating progressive disease with typical symptoms such as acute pain causing loss of mobility Currently there is no cure for OA. Pharmacological treatment and new regenerative technologies such as stem cell therapy are actively being developed, but most of these options are very expensive per se, and side effects are not uncommon. Costeffectiveness is also a major consideration for devising new therapeutic modalities for OA. There are emerging evidences showing that pulsed electromagnetic field (PEMF) can modulae mitochondrial activities for muscle gain. PEMF exposure on top of regular exercise training may promote muscle regeneration and tissue healing. This study aims to conduct a double-blinded, randomized controlled trial to investigate the effect of PEMF treatment on knee pain in patients with knee OA. We hypothesize that PEMF treatment is effective to relief in pain and improve knee function in Knee OA subjects. Based on the aim of this study, older adult patients (aged 50 or above) with a unilateral knee OA with Kellgren-Lawrence grade 2-3 by X-ray, have sedentary lifestyle (Tegner activity level less or equal to 3), no acute knee injuries in past 12 months, no muscle strain in past 12 months and not degenerative joint disease in other joints except the involved knee. To estimate the improvement of patients, isometric quadricep muscle strength, posture assessment, serum myokine level, serum vitamin D level and selfreported outcome with questionnaires will be performed.

It is doubled blinded, a subject 's specific ID card will be provided for each of the enrolled subject and the investigators don't know whether it is PEMF or Sham treatment for that subject's specific ID card. And the investigator will ask the manufactory about the number of grouping at the end of the study.

Subjects will receive PEMF treatment with the duration of 8 weeks, twice a week with total 16 treatment sessions.

Subjects will receive sham PEMF treatment with the duration of 8 weeks, twice a week with total 16 treatment sessions.

Consist of 42 items with 5 subscapes: pain, other symptoms, function in daily living (ADL), function in sport and recreation (Sport/Rec), and knee-related quality of life (QOL) from 0% to 100% where higher score indicate a better outcome in each subscape.

Consists of four items recording the subject's time of spending on physical activities during the past 7 days with a validated Chinese version of the quantitative physical activity questionnaire, and the physical activity level will be evaluated by Metabolic Equivalent of task(MET) per minute and classified as physical level with Low, Moderate or High.

This is a 36-item patient-reported questionnaire that covers eight health domains: physical functioning (10 items), bodily pain (2 items), role limitations due to physical health problems (4 items), role limitations due to personal or emotional problems (4 items), emotional well-being (5 items), social functioning (2 items), energy/fatigue (4 items), and general health perceptions (5 items). Scores for each domain range from 0 to 100, with a higher score defining a more favorable health state.

The peak torque in KG will be recorded with in 2 trials in the 5 seconds isometric muscle strength test.

Phlebotomy (5ml) will be performed on the day before PEMF treatment, at 4- and 8- weeks after commencement of treatment, and at 8 months after the commencement of intervention. The serum will be prepared by centrifugation and kept in a -80o freezer until use. Quantitative analysis for myokines and proteins related to muscle metabolism will be performed by Human Myokine Magnetic Bead Panel (Millipore) with Bioplex-200 bead-based suspension assay system (LKSIHS core facilities), or enzyme-linked immunosorbent assay (ELISA) and report with pg/ml. These include Brain-derived neurotrophic factor (BDNF), Fibroblast growth factor-21 (FGF-21), Interleukin-6 (IL-6), IL-15, Irisin, Myostatin (MSTN)/GDF8, Insulin-like growth factor 1 (IGF-1), FGF-2, IL-8, Follistatin, Musclin, Myonectin, Decorin, Meteorinlike, Osteopontin, Secreted protein acidic and rich in cysteine (SPARC), Klotho, Procollagen type III Nterminal peptide (P3NP), and C- terminal of troponin T1 (TNNT1).

The rate of force development will be determined as the mean slope of the rising force of the first force peak of each of the 2nd to the 6th repetition in the interval of 30-70% exerted peak force. Results are reported as the mean of the two fastest approved trials in body weight per second (BW/s).

Blood samples will be taken under non-fasting conditions. Serum / plasma obtained will be immediately stored at -80°C until analysis. Serum 25(OH) Vit-D assay: Serum 25(OH)Vit-D levels will be measured by commercial 25(OH) Vitamin D ELISA kit (Abcam ab213966) according to the manufacturer's instruction, providing the quantitative determination of 25(OH) Vitamin D3 and 25(OH) Vitamin D2. Sensitivity: 1.98 ng/ml (Range: 0.5 ng/ml - 1010 ng/ml).

The subjective measurement for chronic and acute pain will be recorded by the Visual Analogue Scale (VAS). VAS consists of a 10-cm line which represents the continuum between "painless" and "worst pain from 0 cm to 10 cm. The subject will be asked to draw a mark of it before and after each PEMF treatment session.

Inclusion Criteria: Age 50 or above Unilateral knee OA with Kellgren-Lawrence grade 2-3 by X-ray Sedentary lifestyle (Tegner activity level ≤ 3) No acute knee injuries in past 12 months No muscle strain in past 12 months No degenerative joint diseases in other joints except the involved knee Exclusion Criteria: Age smaller than 50 years old Experienced any concomitant bone fracture, ACL injury, major meniscus injury Any rheumatological diseases Metal implants that would cause interference on MRI Previous contralateral knee injury Recent knee injections (prior 3 months) Physical inability to undertake testing procedures Pregnancy or possibility of pregnancy