Localized hyperthermia induced by microwave diathermy in ...

Knee Surg Sports Traumatol Arthrosc (2011) 19:980–987 DOI 10.1007/s00167-010-1350-7

KNEE

Localized hyperthermia induced by microwave diathermy in osteoarthritis of the knee: a randomized placebo-controlled double-blind clinical trial Arrigo Giombini • Annalisa Di Cesare • Mariachiara Di Cesare • Maurizio Ripani Nicola Maffulli

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Received: 2 April 2010 / Accepted: 25 November 2010 / Published online: 15 December 2010 Ó Springer-Verlag 2010

Abstract Purpose To investigate the effects of hyperthermia on knee osteoarthritis (OA) in a randomized placebo-controlled double-blind clinical trial. Methods Sixty-three patients with clinical evidence and radiographic confirmation of knee OA (Kellgren and Lawrence grades II and III) were randomized to either three 30-min sessions of hyperthermia per week for 4 weeks were administered using a 433.92 MHZ microwave generator or receive placebo treatment (machine not turned on) for same number of sessions. The Western Ontario McMaster Universities (WOMAC) questionnaire and the Timed Up and Go test (TUGT), a performance-based measure of function, were obtained at baseline (week 0), at the end of treatment (week 4), and at final follow-up (week 16). Results The treatment group showed a significant decrease in the overall WOMAC score and each of its components, and in the TGUG test between the beginning (week 0) and the end of treatment (week 4), as well as at final follow-up A. Giombini M. Ripani Department of Health, University of Rome ‘‘Foro Italico’’, Rome, Italy A. Di Cesare Department of Physical Medicine and Rehabilitation, University of Rome ‘‘La Sapienza’’, Rome, Italy M. Di Cesare Department of Social Policy, London School of Economics, London, UK N. Maffulli (&) Centre for Sports and Exercise Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Mile End Hospital, 275 Bancroft Road, London E1 4DG, UK, England e-mail: [email protected]

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(week 16). In the placebo group, a significant fall was only visible in the pain subscore at week 4. However, the mean improvement was only 1 point and was lost at final follow-up (P = 0.332). There was a significant difference in pain -7.4 pre-post (P \ 0.01), -8.1 pre-follow-up (P \ 0.01); stiffness -4.6 pre-post (P \ 0.01), -5.1 pre-follow-up (P \ 0.01); activities daily living (ADL) -30.9 pre-post (P \ 0.01), -33.2 pre-follow-up (P \ 0.01); and WOMAC total score -43 pre-post (P \ 0.01), -46.4 pre-follow-up (P \ 0.01); and in TGUG test -2.4 pre-post (P \ 0.01), -2.9 prefollow-up (P \ 0.01) between the treatment and placebo group over the whole length of the trial. Conclusions A 433.92 MHz microwave hyperthermia regimen showed beneficial effects in patients with moderate knee OA to reduce pain and to improve their physical function. Level of evidence I. Keywords Physical therapy WOMAC scale Thermotherapy

Introduction Osteoarthritis (OA) is a major cause of musculoskeletal pain and disability among middle-aged and elderly people and is responsible for substantial socioeconomic costs [9, 10, 13, 34]. The knee joint is frequently affected by OA [2, 3, 5, 13, 34]. The purpose of management of the knee OA is to lessen pain and stiffness, improve mobility, and minimize disability. Management options include pharmacologic interventions, intra-articular corticosteroid or sodium hyaluronate injections, exercise therapy, surgical management, and modalities including electrotherapy, cold, and heat therapy [4, 11, 14, 21, 27, 36, 56].

Knee Surg Sports Traumatol Arthrosc (2011) 19:980–987

Techniques for heat therapy include the application of superficial heat and application of electromagnetic energy. Frequencies historically used in electromagnetic therapy have been 2,450 [39], 915 [31], 433.92 and 27.12 MhZ [15, 37, 48]. These frequencies differ because of the range of tissue depth in which they can produce heat within tissues [33]. Recently, hyperthermia induced by microwave diathermy at a frequency of 433.92 has been introduced in several European countries in physical medicine and sports traumatology [16–18, 35]. Clinical trials recently demonstrated the effectiveness of hyperthermia in the management of muscle and tendon ailments in athletes [19, 20]. The purpose of the study is to determine the effects of hyperthermia treatment induced by microwave diathermy at 433.92 MHz in patients with symptomatic OA of the knee.

Materials and methods Patients with chronic knee pain referred from the outpatient clinics of the University Institute of Motor Science (IUSM) of Rome with a diagnosis of primary OA of the knee between June 2006 and October 2008 were screened for eligibility. The diagnosis of primary knee OA was based on the clinical and radiologic criteria of the American College of Rheumatology (ACR) [2, 25]. Inclusion criteria were age 60 and above of both sex; mono or bilateral moderate knee OA (Kellgren and Lawrence grading system II and III), knee pain for at least 6 months and no more than

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4 years; independent ambulation without a walking aid; no previous knee surgery or injection of glucocorticoid and/or hyaluronic acid in the last 3 months, no physiotherapy treatment for knee problems in the last month. Exclusion criteria were tumors, joint disease involving the knee such as rheumatic or psoriatic arthritis, joint infections, previous lower limb fractures, neurologic disorders, neck or low back pain with referred pain to the study knee, impaired cutaneous thermal sensitivity, previous deep vein thrombosis. Patients with a cardiac pacemaker or metallic knee implants were not recruited to avoid possible interactions between electromagnetic fields produced by the hyperthermia equipment and these devices. All participants who met the inclusion criteria and agreed to participate in the study received a general explanation of the trial and gave written informed consent. One hundred and one patients were screened, and the 63 patients who fulfilled the study criteria were randomized. Fifty-four patients completed the study without protocol violations. Figure 1 shows the flow chart describing the progress of subjects through the study. The participant demographic and clinical data are shown in Table 1. This was a 16-week duration randomized double-blinded placebo-controlled study. Treatment was administered 3 times a week for 4 weeks. The Western Ontario McMaster Universities (WOMAC) self-reported patient questionnaire was used to evaluate the severity of joint pain, stiffness, and limitations of physical functions [7, 38] and the Timed Up and Go test (TUGT), a performancebased measured of function test, was obtained before the

Fig. 1 Flow of study participants

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Table 1 Baseline characteristics of study and placebo groups (mean and 1 SD)

Sex

Treatment group (n = 35)

Placebo group (n = 28)

23 female; 12 male

19 female; 9 male

Age (y)

67 ± 5.1

67.1 ± 6

BMI

26.3 ± 3.6

27.1 ± 5.2

Duration of symptoms (months)

34 ± 4

35 ± 1

Painful knee (R/L)

14/21

12/16

Kellgren and Lawrence OA classification (II–III grade)

II/17

II/14

III/18

III/14

WOMAC total score

103.1 ± 27.6

101.3 ± 23.4

Pain

19.2 ± 7.3

18.5 ± 7.1

Stiffness ADL

9.7 ± 4.1 74.3 ± 18.9

9.7 ± 3.6 73.1 ± 18.3

TGUG test

15.6 ± 3.3

17.3 ± 2.8

initial treatment (baseline), at the end of the last treatment, and 12 weeks following the last treatment (follow-up) [46]. The Italian version of WOMAC is a reliable and valid instrument to evaluate the severity of OA of the knee [49], TUGT as well is reliable and adequate for clinical use [46]. A thorough clinical examination (including pain on finger pressure, ROM, patellar mobility, sensation of warmth in the knee region) was undertaken at the first visit. Analgesic medications or other modalities were not allowed during the study period. The radiographic features at baseline were assessed according to Kellgren and Lawrence grading system of OA [44]. Randomization and blinding One of the investigators (MDC) who was not involved in the clinical management of the patients used a computer random number generator to determine group allocation, placing the results in sequentially numbered opaque envelopes. All the other procedures were designed to protect blinding for all study subjects and study investigators. Intervention: hyperthermia equipment An ‘‘ALBA Hyperthermia System’’ (RESTEK SRL ITALY) was used for active and sham treatment. It was equipped with a 433.92 MHZ microwaves generator with a maximum output power of 100 W; a 5-mm silicone pad, filled with thermostatic deionized water that prevent overheating of superficial tissues near to the radiant source, a thermostat, to keep water temperature between 30°C and 42°C, and one skin temperature sensor, measuring skin

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temperature in touch with the pad. Accuracy of the temperature control system in the treatment area is ±0.2°C. All participants received three 30-min treatment sessions per week for 4 weeks, for a total of 12 sessions. Hyperthermia treatment was administered at a power of 50 watt, a water pad temperature of 38°C, and a pilot temperature on the skin of 41°C. The thermocouple on the skin was placed perpendicular to the electromagnetic field, to minimize the coupling between the thermocouple and the applied electromagnetic field. The thermocouple was placed on the knee with the patient lying supine, approximately 2 cm supero-laterally to the patella. In the placebo group, the power switch of the apparatus was turned on OFF. All the participants were told that a feeling of warmth on the knee would not be an essential requisite for the treatment to be effective. Thus, with this set-up, patients in the two groups experienced the same sensation of warmth on the skin, as even in the placebo group, a transfer of heat via conduction from the bolus to the skin occurs, just programming with the dedicated software the water bolus temperature to 38°C, making it indistinguishable from the true treatment. In addition, the screen of the hyperthermia apparatus was away from the field of vision of the patients, to prevent them from seeing the graphs of related pilot and water bolus temperature curves on the screen during the treatment. Statistical analysis An a priori power analysis was conducted to determine the size of the two groups using a two tailed unpaired t-test. Based on an difference in means of 0.8 on the WOMAC output measure, a total sample of 53 participants was required to achieve significance at 0.05 (a) and power of 0.8 [12]. Based on an expected 20% dropout rate, we decided to recruit 63 participants. These participants were randomized to active (35 subjects) or inactive (28 subjects) hyperthermia treatment—no loss of power was detected on the harmonic mean of the two unequal samples. Blinding was maintained until the end of the study. Demographic and baseline values of clinical data of all subjects were calculated as the mean values at the first visit. Comparative analysis focused on the end of the treatment (after 4 weeks) and follow-up (16 weeks from the first treatment). A Student’s unpaired t-test was performed to determine whether the two groups were similar at baseline (for demographic and the five outcomes scores), while a repeated measure ANOVA was performed on the pre-treatment to the immediate post-treatment period and pre-intervention value and the one at the latest follow-up difference to determine group (placebo-control) and time effects. An intention to treat approach in all the statistical analyses was adopted. However, a per-protocol analysis was also


performed. It was assigned a constant outcome based on the last observed response to the dropout patients. This involved assigning the baseline response at 4- and 16-week measurement for the eight dropouts at 0 weeks, and the end of treatment (week 4) response for the 16-week measurement for the single dropout patient at 4 weeks. A P level of B.01 was considered to be statistically significant. All data analyses were performed with R version 2.9.1 (http://www. r-project.org/).

Results The two groups showed no statistically significant differences (P = n.s.) regarding their demographic variables (Table 1). The baseline pain, stiffness, function, WOMAC total score, and TUGT test also were not statistically different (P = n.s.). The results for the repeated measure ANOVA on the change in the pre-treatment outcome to the immediate post-treatment period and pre-treatment value

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and the one at the latest follow-up show that, for the five outcomes, there is a statistically significant effect (P \ 0.01) of the group—pain (Fig. 2a), stiffness (Fig. 2b), ADL (Fig. 2c), WOMAC total score (Fig. 2d), TUGT test (Fig. 3). No statistically significant effect (P = n.s.) is detected for time in pain, stiffness, ADL, and WOMAC total score, while a statistically significant time effect exists for the TUGT test. Finally, no statistically significant interaction time-group effects have been detected—pain, stiffness, ADL, WOMAC total score, TUGT test. In other words, this means that the outcome does not change from the immediate post-treatment outcome and the latest follow-up and that the effect of the treatment does not change between immediate post-treatment outcome and the latest follow-up. Table 2 shows the mean values, the SD, and the difference pre-post and pre-follow-up and P-values between groups. No serious adverse effects occurred during the trial, except for two patients in the treatment group who reported a transient aggravation of symptoms, which did not induce them to drop out from the study.

Fig. 2 Outcomes in the treatment and placebo group: pain (a), stiffness (b), physical functions (c), and the WOMAC total score (d); Pre (Week 0), Post (Week 4), and Follow-up (Week 16). Mean ± SD

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placebo group conversely experienced small improvements in the WOMAC total score and in the subscore of joint pain, stiffness and function at the end of treatment, with a further decline (0.23 point) of the subscore of joint pain by the latest follow-up. Likely, these latter results have to be ascribed to a placebo effect. The slight reduction (0.97 point) by the end of treatment in the WOMAC subscore of pain in the placebo group was expected, as the placebo device generated some heat on the treated area, giving the patient the impression that they were receiving some form of treatment. The compliance of our patients was high with the regimen prescribed. The number of patients enrolled in the study was sufficient to ensure a good probability to detect clinically relevant improvements in the hyperthermia group. Furthermore, our placebo device was the same that delivered the effective treatment; thus, the patients were unable to distinguish to which group they had been assigned. To our knowledge, this is the first investigation evaluating the therapeutic effect of 433.92 MHz microwave hyperthermia in patients with symptomatic knee OA. Weinberger et al. demonstrated the beneficial effects of a microwave device operating at 915 MHz with an air cooling system in rheumatoid arthritis patients [53, 54]. The Philadelphia Panel in evidence-based clinical practice guidelines on selected rehabilitation interventions for knee pain included for thermotherapy treatment of OA of the knee only ice massage and ultrasound therapy with no evidence of therapeutic effects [45]. On the contrary, in a recent double-blind study, Ozgonenel et al. demonstrated the effectiveness of ultrasound as treatment modality for pain relief and improvement of functions in patients with

Fig. 3 Outcomes in the treatment and placebo group: timed get up and go test (TGUG) test; Pre (Week 0), Post (Week 4), and Follow-up (Week 16). Mean ± SD

Discussion The most important finding of the present study was the significant improvement in the treatment group in the self-reported measure (WOMAC) and the objective performance-based measure (TUGT). The increase in the difference in this last measure appears to result from pain reduction and, consequently, improvement in function. The Table 2 WOMAC, pain, stiffness, ADL, and TGUG test, mean values, SD, difference pre-post and pre-follow-up and p-values between groups

Treatment group

Placebo

Mean

Mean

SD

SD

Treatment-placebo difference Mean

P-values (between group)

\0.01

WOMAC Pre-post

-46

25.8

-2.9

9.3

-43.0

Pre-follow

-46.8

27.2

-0.4

12.7

-46.4

Pre-post

-8.4

5.7

-1.0

1.3

-7.5

Pre-follow

-8.6

6.0

-0.6

3.0

-8.1

Pain \0.01

Stiffness Pre-post

-5.1

3.3

-0.5

2.1

-4.6

Pre-follow

-5.2

3.8

-0.1

2.9

-5.1

\0.01

ADL

123

Pre-post

-32.4

18.6

-1.5

8.2

-30.9

Pre-follow

-33

19.7

0.3

9.8

-33.2

TGUG test Pre-post

-2.3

2.1

0.1

1.7

-2.4

Pre-follow

-1.9

2.4

1.0

1.4

-2.9

\0.01

\0.01


knee OA [43]. In a systematic review on thermotherapy for treatment of OA, Brosseau et al. reported the lack of evidences about thermotherapy such as hot-packs in patients with knee OA [6]. However, trials using different types of diathermy were excluded from his review. Short wave diathermy (SWD) equipment, which uses electromagnetic radiation at 27.12 MHz, delivered in either a continuous (CSWD), or a pulsed (PSWD) mode, remains the most widely used forms of diathermy still in use in most physiotherapy departments. Despite the popularity of this modality, the effectiveness of SWD and PSWD for the treatment of OA has been reported only in studies with a relatively poor experimental design [48, 50, 51, 55]. In knee OA, the outcome of clinical trials varies from positive [41] to absence of evidence of a beneficial effect [29, 47]. Recently, Mei-Hwa et al. [40], in a controlled study, documented a significant decrease both in synovial thickness and in knee pain index score with the use of a series of SWD treatments in patient with knee OA. More recently, Cetin et al. [8] demonstrated that among different physical agents, the use of SWD before isokinetic exercises in women with knee OA leads to increased exercise performance, reduced pain, and improved function. However, the physical characteristics of SWD systems do not allow proper heating to the depth of the osteoarthritic tissues [22, 42, 52]. The activity of cartilage degrading enzymes is influenced by joint temperature. As the temperature increases from the normal 33°C to that of 36°C found in arthritic patients, these enzymes are markedly more active [23, 32, 53]. Temperatures above 41°C decrease the activity of these enzymes [53]. It was hypothesized that the pain reducing effects and improvement in functional activity in the participants with knee OA in this study may arise from the temperature gradients reached during the sessions [31, 49]. Above 41.5°C and up to 45°C, the increase in tissue temperature considerably enhances local blood perfusion [1, 26], producing most of the beneficial effects of hyperthermia. In a recent in vivo study, 433.92 MHz microwave hyperthermia treatment increased and maintained muscle temperature locally by 6.3–11.4°C from the baseline temperature without muscle damage [26]. The improvement in joint stiffness and functional status might result from enhanced blood circulation in the periarticular compartment of the knee [1], increase in collagen tissue extensibility [30], or positive effects on cartilage differentiation [31]. Reduced inhibition of muscular contraction, likely from pain relief, might be another explanation for the improvement of the physical function in patients treated with hyperthermia. The underlying mechanism for the pain reducing effect of hyperthermia in both acute and chronic conditions is still a matter of debate [24, 28].

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The present study does present limitations. First, the participants in this study suffered from moderate OA (II and III Kellgren Lawrence grade). Therefore, our results might not apply to patients with radiographically severe knee OA (Kellgren-Lawrence IV and V). Second, we do not know whether the results obtained would hold at a longer follow-up. Third, one might also need to consider other indices of disease progression to assess the full effects of hyperthermia, such as tissue temperature, with blood cell count, tissue damage, or plasma extravasation.

Conclusion The present study showed beneficial effects of a 433.92 MHz microwave hyperthermia regimen in patients with moderate knee OA to reduce pain and to improve their physical function. To fully characterize the clinical effects of hyperthermia, further studies should be performed recruiting patients with more advanced knee OA, with a longer follow-up.

References 1. Akyurekli D, Gerig LH, Raaphorst GP (1997) Changes in muscle blood flow distribution during hyperthermia. Int J Hyperthermia 13:481–496 2. Altman R, Asch E, Bloch D, Bole G, Borenstain D, Brandt K, Christy W et al (1986) Development of criteria for the classification and reporting of osteoarthritis. Classification of osteoarthritis of the knee. Diagnostic and therapeutic criteria committee of the American rehumatism association. Arthritis Rheum 29:1039–1049 3. Altman RD (1997) The syndrome of osteoarthritis. J Rheumatol 24:766–767 4. Bezalel T, Carmeli E, Katz-Leurer M (2010) The effect of a group education programme on pain and function through knowledge acquisition and home-based exercises among patients with knee osteoarthritis: a parallel randomised single-blind clinical trial. Physiotherapy 96:137–143 5. Breedveld F. C. (2004) Osteoarthritis—the impact of a serious disease. Rheumatology 43 (S 1): i 4–8 6. Brosseau L, Yonge KA, Robinson V, Marchand S, Judd M, Wells G, Tugwell P (2003) Thermotherapy for treatment of osteoarthritis. Cochrane Database Syst Rev (4):CD004522 7. Bruce B, Fries J (2004) Longitudinal comparisons of the Health Assessment Questionnaire and (HAQ) and Western Ontario and Mc Master Universities Osteoarthrtis index (WOMAC). Arthritis Rheum 51:730–737 8. Cetin N, Aytar A, Atalay A, Akman MN (2008) Comparing hot pack, short-wave diathermy, ultrasound, and TENS on isokinetic strength, pain, and functional status of women with osteoarthritic knees: a single-blind, randomized, controlled trial. Am J Phys Med Rehabil 87:443–451 9. Corti MC, Rigon C (2003) Epidemiology of osteoarthritis: prevalence, risk factors and functional impact. Aging Clin Exp Res 15:359–363

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986 10. D’Ambrosia RD (2005) Epidemiology of osteoarthritis. Orthopedics 28:S201–S205 11. Evcik D, Sonel B (2002) Effectiveness of a home-based exercise therapy and walking program on osteoarthritis of the knee. Rheumatol Int 22:103–106 12. Faul F, Erdfelder E, Lang AG, Buchner A (2007) G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods 39:175–191 13. Felson DT, Zhang Y, Hannan MT et al (1997) Risk factors for incident radiographic knee osteoarthritis in the elderly: the Framingham study. Arthritis Rheum 40:728–733 14. Fife RS (1997) Osteoarthritis: a. Epidemiology, pathology, and pathogenesis. In: Klippel J (ed) Primer on the rheumatic diseases, 11th edn. Arthritis Foundation, Atlanta, pp 216–218 15. Gabriele P, Amichetti M, Orecchia R, Valdagni R (1995) Radiation therapy and hyperthermia in advanced or recurrent parotid tumors. Cancer 75:908–913 16. Gelvich EA, Mazokhin VN (2002) Contact flexible microstrip applicators (CFMA) in a range from microwaves up to short waves. IEEE Trans Biomed Eng 49:1015–1023 17. Giombini A, Casciello GF, Di Cesare MC, Di Cesare A, Dragoni S, Sorrenti D (2001) A controlled study on the effects of hyperthermia at 434 MhZ and conventional ultrasound upon muscle injuries in sport. J Sports Med Phys Fitness 41:521–527 18. Giombini A, Di Cesare A, Casciello GF, Sorrenti D, Dragoni S, Gabriele P (2002) Hyperthermia at 434 MhZ in the treatment of overuse sport tendinopathies: a randomised controlled clinical trial. Int J Sports Med 23:207–211 19. Giombini A, Di Cesare A, Safran MR, Ciatti R, Maffulli N (2007) Short term effectiveness hyperthermia for supraspinatus tendinopathy in athletes. A short term randomized controlled study. Am J Sport Med 34:1247–1253 20. Giombini A, Giovannini V, Di Cesare A, Pacetti P, IchinosekiSekine N, Shiraishi M, Naito H, Maffulli N (2007) Hyperthermia induced by microwave diathermy in the management of muscle tendon and injuries. Br Med Bull 83:379–396 21. Griffin MR, Brandt KD, Liang MH, Pincus T, Ray WA (1995) Practical management of osteoarthritis. Integration of pharmacologic and non pharmacologic measures. Arch Fam Med 4:1049–1055 22. Guy AW, Lehamnn JF, Stonebridge JB (1974) Therapeutic applications of electromagnetic power. Proc IEEE 62:65–75 23. Harris ED, McCroskery PA (1974) The influence of temperature and fibril stability on degradation of cartilage collagen by rheumatoid synovial collagenase. N Engl J Med 290:1–6 24. Haveman J, Van Der Zee J, Wondergem J, Hoogeveen JF, Hulshof MC (2004) Effects of hyperthermia on the peripheral nervous system: a review. Int J Hyperthermia 20:371–391 25. Hocberg MC, Altman RD, Brandt KD, Clark BM, Dieppe PA, Griffin MR et al (1995) Guidelines for the medical management of osteoarthritis Part II. Osteoarthritis of the knee. American College of Rheumatology. Arthritis Rheum 38:1541–1546 26. Ichinoseki-Sekine N, Naito H, Saga N, Ogura Y, Shiraishi M, Giombini A, Giovannini V, Katamoto S (2007) Changes in muscle temperature induced by 434 MHz microwave hyperthermia. Br J Sports Med 41:425–429 27. Jordan KM, Arden NK, Doherty M, Bannawarth B, Bijlsma JW, Dieppe P et al (2003) EULAR recommendations 2003: an evidence based approach to the management of the knee osteoarthritis. Report of a task force of the standing committee for international clinical studies including therapeutic trials (ESCISIT). Ann Rheum Dis 62:1145–1155 28. Kanui TI (1987) Thermal inhibition of nociceptor driven spinal cord neurons in the cat: a possible neuronal basis for thermal analgesia. Brain Res 402:160–163

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Knee Surg Sports Traumatol Arthrosc (2011) 19:980–987 29. Laufer Y, Zilberman R, Porat R, Nahir AM (2005) Effect of pulsed short wave diathermy on pain and function of subjects with osteoarthritis of the knee: a placebo controlled double blind clinical trial. Clin Rehabil 19:255–263 30. Lehman JF, Masock AJ, Warren CG, Koblaski JN (1970) Effect on therapeutic temperatures on tendon extensibility. Arch Phys Med Rehabil 51:481–487 31. Lehmann JF, Delateur BJ (1990) Therapeutic heat. In: Lehmann JF (ed) Therapeutic heat and cold, 4th edn. Williams and Wilkins, Baltimore, pp 417–581 32. Lehmann JF, Guy AW, Stonebridge JB, Delateur BJ (1978) Evaluation of a therapeutic direct contact 915 MHz microwave applicator for effective deep tissue heating in humans. IEEE Trans Microw Theory MTT 26:556–563 33. Leon SA, Asbell SO, Arastu HH, Edelstein G, Packel AJ, Sheehan S, Daskai I, Guttmann GG, Santos I (1993) Effects of hyperthermia on bone. II. Heating of bone in vivo and stimulation of bone growth. Int J Hyperthermia 9:77–87 34. Mannoni A, Briganti MP, Di Bari M et al (2003) Epidemiological profile of symptomatic osteoarthritis in older adults: a population based study in Dicomano, Italy. Ann Rheum Dis 62:576–578 35. Marini P, Guiot C, Baiotto B, Gabriele P (2001) Measures of specific absorption rate (SAR) in microwave hyperthermic oncology and the influence of the dynamic bolus on clinical practice. Radiol Med 102:159–167 36. Marks R, Cantin D (1997) Symptomatic osteo-arthritis of the knee: the efficacy of physiotherapy. Physiotherapy 83:306–312 37. Marks R, Ghasserni M, Duarte R, Van Nguyen JP (1999) A review of the literature on shortwave diathermy as applied to osteoarthritis of the knee. Physiotherapy 85:304–316 38. McConnell S, Kolopack P, Davis AM (2001) The Western Ontario and McMaster Universities Osteoarthritis index (WOMAC): a review of its utility and measurement properties. Arthritis Rheum 45:453–461 39. McMeeken J (1994) Tissue temperature and blood flow: a research based overview of electrophysical modalities. Aust J Physioter 40:49–57 40. Mei-Hwa J, Huei-Ming C, Chung Li W, Yeong-Fwu L, Li-ying T (2006) Effects of repetitive shortwave diathermy for reducing synovitis in patients with knee osteoarthritis:an ultrasonographic study. Phys Ther 86:236–244 41. Moffett JA, Richardson PH, Frost H, Osborn A (1996) A placebo controlled double blind trial to evaluate the effectiveness of pulsed short wave therapy for osteoarthritic hip and knee pain. Pain 67:121–127 42. Osterveld FGJ, Rasker JJ, Jacobs JWG, Overmars HJA (1992) The effect of local heat and cold therapy on the intraarticular and skin surface temperature of the knee. Arthritis Rheum 35:146–151 43. Ozgonenel L, Aytekin E, Durmusoglu G (2009) A double-blind trial of clinical effects of therapeutic ultrasound in knee osteoarthritis. Ultrasound Med Biol 35:44–49 44. Peterson IF, Boegard T, Saxne T, Silman AJ, Svennsson B (1997) Radiographic osteoarthritis of the knee classified by the Ahlback and Kellgren & Lawrence systems for the tibiofemoral joint in people aged 35–54 years with the chronic knee pain. Ann Rheum Dis 56:493–496 45. Philadelphia Panel evidence-based clinical practice guidelines on selected rehabilitation interventions for knee pain. Philadelphia Panel. (2001) Phys Ther 81:1675–1700 46. Piva SR, Fitzgerald GK, Irrgang JJ, Bouzubar F, Starz TW (2004) Get up and go test in patients with knee osteoarthritis. Arch Phys Med Rehabil 85:284–289 47. Rattanachaiyanont M, Kuptniratsaikul V (2008) No additional benefit to shortwave diathermy over exercise program for knee


48.

49.

50.

51.

osteoarthritis in peri/post-menopausal women: an equivalence trial. Osteoarthr Cartil 16:823–828 Robertson V, Ward A, Low J, Reed A (2006) Heat and cold. In: Electrotherapy explained principle and practice, 4th ed. Butterworth-Heinemann-Elsevier, London, pp 325–424 Salaffi F, Leardini G, Canesi B, Mannoni A, Fioravanti A, Caporali R, Lapadula G, Punzi L (2003) Gonarthrosis and quality of life assessment (GOQOLA). Reliability and validity of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis index in Italian patients with osteoarthritis of the knee. Osteoarthr Cartil 11:551–560 Sekins KM, Lehmann JF, Esselman P (1984) Local muscle blood flow and temperature responses to 915 MhZ diathermy as simultaneously measured and numerically predicted. Arch Phys Med Rehabil 65:1–7 Shields N, Gormley J, O’Hare N (2001) Short- wave diathermy: a review of existing clinical trials. Phys Ther Rev 6:101–118

987 52. Shields N, Gormley J, O’Hare N (2002) Short- wave diathermy: current clinical and safety practice. Physiother Res Int 7:191–202 53. Spiegel TM, Hirschberg J, Taylor J, Paulus HE, Furst DE (1987) Heating rheumatoid knees to an intra-articular temperature of 42.1°C. Ann Rheum Dis 46:716–719 54. Weinberger A, Abramonvici A, Fadilah R, Levy A, Giler S, Lev A (1990) The effect of local deep microwave hyperthermia on experimental zymosan-induced arthritis in rabbits. Am J Phys Med Rehabil 69:239–244 55. Weinberger A, Fadilah R, Lev A, Shohami E, Pinkhas J (1989) Treatment of articular effusions with local deep microwave hyperthermia. Clin Rheum 4:461–466 56. Zizic TM, Hoffman KC, Holt PA, Hungerford DS, O’Dell JR, Jacobs Ma et al (1995) The treatment of osteoarthritis of the knee with pulsed electrical stimulation. J Rheumatol 22:1757–1761

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