The Assessment of TECAR Therapy Efficacy to Manage Lateral Epicondylitis: A Randomized Clinical-Trial

Abstract

Background:

Lateral epicondylitis, a chronic painful condition within the lateral epicondyle, is one of the most prevalent arm pathologies. To date, various therapeutic strategies have been applied to manage the condition; however, they might be accompanied by adverse effects or temporary responses. TECAR therapy, a diathermy technique, has yielded promising outcomes in numerous musculoskeletal pathologies. The current study aims to investigate the impact of TECAR therapy on lateral epicondylitis.

Materials and Methods:

The current double-blinded randomized clinical trial has been conducted on 46 patients with lateral epicondylitis who were allocated into two groups of controls (treatment with 15 mg meloxicam and cock-up brace for the period of 2 weeks) and intervention who received similar treatment as well as five sessions of TECAR therapy (every other day in a week). Visual Analogue Scale (VAS) and Disabilities of the Arm, Shoulder and Hand (DASH) were applied to evaluate treatment response.

Results:

Both interventions led to significantly improved VAS (P < 0.001) and DASH (P < 0.001) scores, while the comparison of the groups revealed statistically significant improvement in the DASH score of the intervention groups (P < 0.05), but VAS scores did not differ (P > 0.05) by both the end of the intervention and one-month follow-up assessments.

Conclusion:

Based on the findings of the current study, TECAR therapy is an effective modality for the treatment of lateral epicondylitis considering its remarkable influence on both pain relief and functional rehabilitation. Further studies are recommended.

INTRODUCTION

Lateral epicondylitis, a chronic painful condition within the lateral epicondyle, commonly known as tennis elbow, is one of the most prevalent arm pathologies involving 1-3% of the general population and 2-23% of the occupational populations, mostly affecting individuals with age range of 35-50 years old.[1,2]

Although the etiology of lateral epicondylitis is not well-elucidated, various theoretical matters including repetitive/excessive mechanical loads, and contusions) and structural factors (morphologic, cellular, metabolic) have been hypothesized.[3] It has been proposed that angiofibroblastic degeneration or hyperplasia within the common extensor tendon of the elbow, particularly affecting the extensor carpi radialis brevis are responsible for the incidence of this chronic painful condition.[4]

Lateral epicondylitis is generally diagnosed through clinical assessments such as pain complaint via pressing on the lateral epicondyle of the elbow or a positive Cozen’s test diagnosed via pain deterioration while resisting against wrist extension with fully extended elbow enforces the diagnosis.[5]

Various therapeutic approaches from conservative noninvasive ones to more intensive modalities have been recommended. These treatments include activity modifications, consuming nonsteroidal anti-inflammatory drugs (NSAIDs), bracing, extracorporeal shock wave therapy, YAG laser treatment, and acupuncture. However, data about the efficacy of each modality as well as assessing their advantages and disadvantages are controversial and inconsistent.[2]

Currently, diathermy is one of the physical modalities that has been widely applied in various musculoskeletal disorder. One of the most recent diathermy-based modalities is TECAR therapy (which stands for the Spanish term “Tranferencia Electica Capacitiva Resistiva”), which increases the tissue’s intrinsic metabolism through intertissue energy transfer without releasing energy to the outside and theoretically leads to increased microcirculation flow, vasodilation (increased oxygenation), and tissue heat.[6] TECAR therapy mechanism of action is exerted through two capacitive and resistive modes. The first one is considered appropriate for tissues with higher water and electrolyte content, such as soft tissues and muscles, whereas the resistive system focuses on larger and more resistant tissues such as tendons, bones and articulations.[7,8] Given that, this modality acts through intertissue energy transfer without releasing energy to the outside and theoretically leads to increased microcirculation flow, vasodilation (increased oxygenation), and tissue heat.[6] Nevertheless, a limited number of studies have evaluated the efficacy of TECAR therapy on tendinopathies. Besides, to the best of our knowledge, there is only a study in the literature assessing TECAR therapy on seven patients with lateral epicondyle tendinopathy.[9] Accordingly, this modality has limitedly been applied in the tendinopathies. The current study aims to investigate this approach through a randomized clinical trial.

MATERIALS AND METHODS

Study population

The current double-blinded randomized clinical trial has been conducted on 46 patients with lateral epicondylitis who were referred to the outpatient clinics of Physical Medicine and Rehabilitation affiliated with Isfahan University of Medical Sciences from December 2021 to April 2023.

The study proposal was designed based on the tenets of the Helsinki Declaration and proposed for the Ethics Committee of Isfahan University of Medical Sciences where it was approved via code number “IR.MUI.MED.REC.1400.705”. Besides, the study has been registered in the Iranian Registry of Clinical Trials with the code number “IRCT20220115053718N1”. The study protocol was explained to the patients, they were reassured regarding the confidentiality of their personal information and signed written consent of participation in the study.

Eighteen-to-sixty-five-year-old individuals who were diagnosed with lateral epicondylitis by a physical medicine and rehabilitation specialist whose pain complaint elongated for the least period of a month and had the baseline Visual Analogue Scale (VAS) score of >3 were included. Any medical history of inflammatory disease or trauma/injury to the involved elbow, history of surgery, physical therapy or local injections on the involved elbow within the previous 6 months, the diagnoses other than lateral epicondylitis and the presence of any contraindications for TECAR therapy (pregnancy, presence of insulin pumps or pacemaker, malignancies, open skin lesions and thrombophlebitis) were defined as the unmet criteria. Those who were uncooperative during the interventions (absence for more than two sessions), refused to participate in postintervention visits and presented remarkable adverse effects requiring withdrawal from the intervention approach were excluded.

The patients entered into the study through convenience sampling. Then, they were randomly assigned into groups of intervention and control using Random Allocation Software by which each patient was provided with a random number allocating him/her to one of the groups.

The person who interviewed the patients and the biostatistician were blinded to the group of the studied individuals. In this regard, the physician who visited the patients from baseline to the end of the study was different from the one who applied the interventions and the patients were just presented as group A or B. The method of categorizing the patients as group A/B was administered to the biostatistician, as well.

Intervention

After the division of the patients into two groups of intervention versus controls. All the patients were treated with daily 15 mg meloxicam (Osvah Pharmacy, Iran) and cock-up brace for the period of 2 weeks; while the intervention groups also underwent five sessions of TECAR therapy (every other day in a week).

TECAR therapy

TECAR therapy was performed with the WINBACK 3 device made in France, with a frequency of 500 Hz and intensity of 20 to 40% (determined based on the patient’s tolerability) and medium Capacitive Energy Transfer electrode (60 mm). The patient was in a sitting position and the dorsal part of the forearm and the lateral epicondyle were smeared with a conductive cream. A resistant electrode was attached to the forearm. The procedure was initiated with the moving of the resistant electrode in a circular pattern around the area where the hand extensor tendons were originating for 10 min. Afterwards, the active capacitive electrode was moved in a circular pattern from the origin of the extensor muscles to the fingers for another 10 min.[10]

To minimize the probable bias, all the procedures were performed by an expert physical medicine and rehabilitation specialist.

Data collection

A checklist was designed to gather the patients’ data. Given that, the demographic characteristics including age, gender, occupation, the dominant hand, the side of the involved hand and the duration of lateral epicondylitis were recorded in the checklist.

Outcomes

The primary outcomes of the study were to assess the patient’s response to the interventions using the visual analog scale (VAS) and Disabilities of the Arm, Shoulder and Hand (DASH). The questionnaires were filled at baseline, by the end of the interventions, and within a month after the end of the study.

Instruments

Visual analogue scale (VAS)

VAS is a 10-score scale ranging from zero as the least pain complaint to 10 as the most. A score of 1-3, 4-7, and 8-10 indicates mild, moderate, and severe pain.[11]

Disabilities of the arm, shoulder and hand (DASH)

This instrument is a means of assessing upper extremity musculoskeletal disease within a week. It contains 30 questions with 5-Likert scale scores assessing the function of the upper extremity including 21 questions about the daily activities limitations, 5 ones about the pain severity during activities and sleep, weakness and the rigidity of the limb, and 4 questions about the effects of this pain on social and occupational activities. The final result is calculated by the summation of the responses and higher scores indicate more severe status.[12] DASH questionnaire has been validated in Persian with validity and reliability of 80% and 96%, respectively.[13]

Statistical analysis

The obtained data was entered into the Statistical Package for Social Sciences (SPSS Inc., PASW Statistics for Window Chicago) version 24. The normality of data distribution was assessed using the Kolmogorov-Smirnov test. The categorical variables were presented in absolute numbers and percentages, while continuous ones in mean ± standard deviation. Chi-square or Fisher’s exact tests were applied to compare the categorical data. The continuous variables that did not have normal distribution were presented in median and interquartile range. Accordingly, the trend of changes in VAS was compared using nonparametric measures including the Kruskal-Wallis test. Normal distribution in DASH led to the use of repeated measure ANOVA to compare the groups. Moreover, due to the non-normal distribution of baseline VAS, Mann-Whitney U was used, while baseline DASH was compared using an independent t-test. ANCOVA or quad ANCOVA tests were applied to compare the groups’ differences in assessing DASH and VAS, respectively. A P value less than 0.05 was considered the level of significance.

RESULTS

In the current study, the eligibility of 60 individuals with lateral epicondylitis for participation in the study was evaluated among whom seven did not meet the study criteria and three refused to participate in a scientific experiment. Given that, 50 entered into the study who were randomly assigned into one of the intervention (n = 25) versus control (n = 25) groups. However, a person lost to follow-up and a person withdrew from the study in the case group; while two patients (one did not receive the medications of the control group and the other did not refer for follow-up visits) were in the control group. Eventually, 46 patients in two equal 23-member groups fulfilled the study. Figure 1 depicts the consort diagram of the studied population.

Figure 1.

Consort diagram of the studied population

The mean age of the studied population was 45.54 ± 7.75 years old who were predominantly consisted of males (52.1%).

The demographic characteristics of the studied patients are demonstrated in Table 1. The mean age of the intervention and control groups was 46.39 ± 8.04 versus 44.78 ± 7.46 years old, respectively (P = 0.181). Besides, the groups were not statistically different in terms of gender distribution (P = 0.555), the duration of coming down with lateral epicondylitis (P = 0.208), the involvement of the dominant hand (P = 0.760), the side of the involved hand (P = 0.699), and their occupation (P = 0.648).

Table 1.

The demographic information of the studied population

Variables	Intervention (n=23)	Control (n=23)	P
Age (year), mean±standard deviation	46.39±8.04	44.78±7.46	0.181#
Gender (female), n (%)	12 (52.2)	10 (43.5)	0.555*
The duration of the disease (week), mean±standard deviation	12.78±11.90	13.43±6.75	0.208#
Dominance of the involved hand (yes), n (%)	15 (65.2)	14 (60.9)	0.760*
The side of the involved elbow (right), n (%)	18 (78.3)	20 (87)	0.699**
Occupation, n (%)
Home keeper	9 (39.1)	6 (26.1)	0.638*
Self-employed	8 (34.8)	10 (43.5)
Employee	6 (26.1)	7 (30.4)

*Chi-square. **Fisher’s exact test. ^#Independent t-test

The pain score (P = 0.472) and the DASH score (P = 0.711) did not differ between the groups in baseline assessments. Quade ANCOVA test revealed no difference between the groups in terms of pain severity in the assessments done by the end of the interventions (P = 0.262) and within a month (P = 0.085). However, DASH scores remarkably improved in the intervention group compared with the controls in both the assessments done by the end of the interventions (P = 0.002) and within a month (P = 0.006). The pain and DASH measurements in each group represented a significant decrease in both groups by the end of the intervention (P < 0.001) as well as the assessments performed a month later (P < 0.001) [Table 2]. Post hoc Bonferroni test revealed that VAS and DASH scores measured at the end of the interventions were statistically less than the baseline assessments (P < 0.05). Moreover, those measured within a month after the interventions were statistically less than those measured at baseline as well as the assessments done at the end of the interventions (P < 0.05). Furthermore, the decrease in both VAS and DASH scores was significantly more in the intervention group compared with the controls (P < 0.05) [Table 3].

Table 2.

Primary outcomes of the study in terms of pain and function at baseline, by the end of the intervention and within a month

Variables		Baselines	End of the interventions	Within a month	P (within a group)
VAS, median [IQR]	Intervention	7 [6, 8]	4 [3, 5]	3 [3, 4]	<0.001*
	Control	7 [6, 8]	5 [4, 6]	3 [3, 4]	<0.001*
P (between the groups)		0.472ⴄ	0.262¥	0.085¥
DASH, mean (standard deviation)	Intervention	46.45 (10.16)	(8.36) 39.61	(7.64) 34.98	<0.001**
	Control	47.42 (7.16)	(6.16) 42.46	(6.81) 38.62	<0.001**
P (between the groups)		0.711€	0.002α	0.006α

*Kruskal-Wallis, ^ⴄMann-Whiney U, ^¥Quade ANCOVA, ^€Independent t-test, ^αANCOVA, **Repeated measure ANOVA test

Table 3.

The trend of changes in the primary outcome measures in terms of pain and function

Variables		The difference of end of the intervention with baseline	The difference of a month after the intervention with baseline
VAS, median (IQR)	Intervention	−3 (−3, −2)	−4 (−4, −3)
	Control	−2 (−3, −1)	−3 (−4, −2)
	P*	0.041	0.034
DASH, mean (standard deviation)	Intervention	−6.84 (2.76)	−11.47 (3.38)
	Control	−4.95 (2.78)	−8.80 (4.80)
	P**	0.026	0.035

*Mann-Whitney. **Independent t-test

DISCUSSION

The current study tried to investigate the efficacy of TECAR therapy on the rehabilitation of upper extremities affected by lateral epicondylitis. The findings of our investigation revealed remarkable rehabilitation following five sessions of TECAR therapy; as both pain and function of the involved hand improved in the 1-month follow-up assessments. In more detail, the trend of changes in pain complaints using VAS and hand function using DASH revealed remarkable improvement in both interventions. Nevertheless, the comparison of pain severity by the end of the intervention and within a month later did not show any difference between the groups, while DASH scores were significantly better among those treated with TECAR therapy than the controls.

Lateral epicondylitis is a relatively common musculoskeletal complaint which therapeutic approach is a matter of debate; however, several treatments have been proposed.[1,2] Besides, TECAR therapy is a novel modality that has been successfully applied for several chronic musculoskeletal disorders[9]; however, to the best of our knowledge, the current investigation is one of the first dedicated to assessing this modality of lateral epicondylitis.

Surfing the literature revealed only a study assessing the use of TECAR therapy on lateral epicondyle tendinopathy in which TECAR therapy was applied in both a capacitive and resistive mode for three sessions a week and a total of 6 weeks culminating in significantly improved symptoms, but no difference in comparison to the conventional therapeutic strategies.[9] Despite the similarity of the outcomes in this study with ours, they applied TECAR therapy for 18 sessions and followed their patients twice, within 3 and 6 months after the intervention, while our investigation was limited to five sessions and a 1-month follow-up only. The superiority of our study is the remarkably larger study population.

Ribeiro et al.[8] compared the efficacy of TECAR therapy versus a combination of transcutaneous electrical nerve stimulation (TENS), iontophoresis, ultrasound and LASER on patients suffering from rotator cuff tendinopathy. After 8 weeks of interventions, they concluded that TECAR therapy was accompanied by more rapid resolution of the acute inflammatory process, early recovery of the joint passively and actively and rapid recovery of muscle strength. Another investigation was performed by Morelli and colleagues who recommended 10 sessions of TECAR therapy for patients with chronic low back pain and represented more remarkable pain reduction in those treated with TECAR therapy compared with the counterparts undergoing oxygen-ozone therapy.[14] The superiority of TECAR therapy over laser therapy was mentioned in another study on low back pain representing that 10 sessions of TECAR therapy not only could effectively reduce pain but also had more stable outcomes.[15] Further studies also have presented promising outcomes following TECAR therapy for various types of tendinopathies including Achilles, biceps and triceps tendinopathies. Despite their unanimity on the beneficial effects of TECAR therapy, they were not always in agreement regarding the superiority of this modality over the others.[16,17]

TECAR therapy is a type of noninvasive electrothermal treatment classified as deep thermotherapy and the experiments on this modality are mostly limited to sport-related injuries including bone, joint, muscle, and tendon injuries.[18] The most significant superiority of this modality over the other types of thermotherapy refers to its ability to penetrate the body tissues deeply which speeds up the recovery time. This modality is available in capacitive or resistive modes. The first one generates the heat energy into the superficial tissues, with selective action on soft tissues with low impedance; while the latter targets denser tissues with more fat and fiber (such as bones, ligaments, and tendons).[19,20,21]

According to the body of evidence, the influences of TECAR therapy are induced through capacitive and resistive mechanisms resulting in vasodilatory effects which promote oxygenation to the surrounding tissues supplying from the dilated vessels. Besides, microcirculation of the affected area would enhance and a considerable rise in internal temperature would occur.[22] Given that, the emitted radiofrequency energy through TECAR therapy relaxes muscles and ligaments and improves nervous system repair. Moreover, it is estimated that TECAR therapy can reduce edema in the injured area, the origin of the extensor muscle and tendons in this study, which seems logical as the underlying pathophysiology for lateral epicondylitis is increased edema and cytokine release in the surrounding tissues causing pain.[23]

Limitations

Despite all the strong points of the current study, particularly its novelty with randomized clinical trial design for TECAR therapy use for lateral epicondylitis, it contains remarkable limitations such as a small sample population or failure to evaluate the level of daily physical activity regardless of the patient’s occupation. Considering the temporary effects of these interventions, long-term studies with more detailed information are strongly recommended.

CONCLUSION

Based on the findings of the current study, TECAR therapy is an effective modality for the treatment of lateral epicondylitis considering its remarkable influence on both pain relief and functional rehabilitation. Further studies are recommended.

Ethics approval and consent to participate

The study was approved by the Ethical Committee of the Isfahan University of Medical Sciences via code number “IR.MUI.MED.REC.1400.705”. Besides, the study has been registered in the Iranian Registry of Clinical Trials with the code number “IRCT20220115053718N1”. The study protocol was explained to the patients, and they were reassured regarding the confidentiality of their personal information and signed written consent for participation in the study.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Isfahan University of Medical Sciences sponsored the study with grant number 3400725.