Electroacupuncture Treatment in Osteoarthritis Pain of the Knee for Geriatric Patients

Abstract

Background:

Joint pain or discomfort from osteoarthritis (OA) affects a large percentage of middle age and elderly persons in all countries. The frequency of OA-related physical disability makes OA one of the leading causes of disability in the elderly.

Objective:

To assess the efficacy of electroacupuncture in providing pain relief by 10 sessions of therapy to geriatric patients with OA pain of the knee.

Patients:

A case series of 42 patients with OA pain of the knee in Indonesia were treated using electroacupuncture from January 2009 to August 2009.

Intervention:

All patients received electroacupuncture treatment on bilateral Heding, Xiyan, and ST 36 Zusanli for 10 consecutive days.

Main Outcome Measures:

The primary outcome measure was change in pain measured using the Numeric Analogue Scale (0–10) at the end of the study (day 10).

Results:

At the end of the treatment, a paired t-test showed significant improvement in the pain scores after 10 treatments compared to baseline (P<0.05).

Conclusions:

Adjunctive electroacupuncture treatment seems to provide added improvement to standard care in elderly patients with OA of the knee.

Introduction

Osteoarthritis (OA), formerly referred to as osteoarthrosis and degenerative joint disease, is the most common form of arthritis.¹ Joint pain or discomfort from OA affects a large percentage of middle age and elderly persons in all countries. Clinically, the disease is characterized by joint pain, tenderness, limitation of movement, crepitus, occasional effusion, and variable degrees of local inflammation, but without systemic effects. Pathologically, the disease is characterized by irregularly distributed loss of cartilage more frequently in areas of increased load, sclerosis of the subchondral bone, subchondral cysts, marginal osteophytes, increased metaphyseal blood flow, and variable synovial inflammation.² Its high prevalence, especially in the elderly, and the frequency of OA-related physical disability make OA one of the leading causes of disability in the elderly, especially with respect to weight-bearing functional tasks.³ Therapies tested for OA include conventional nonsteroidal anti-inflammatory drugs (NSAIDs), cyclooxygenase-2 (COX-2) inhibitors, interleukin-1 (IL-1) inhibitors, and corticosteroids. Because of relatively high toxicity rates and the increased rates of cardiovascular events associated with COX-2 inhibitors and with some conventional NSAIDs, many of these drugs are not appropriate as long-term treatment choices for older persons with OA.⁴

Acupuncture as a technique consists of appropriately inserting and manipulating special needles in selected points on the body. The historical literature on acupuncture contains a wealth of descriptions of the treatment of numerous pain conditions from more than 22 centuries and many countries spanning all major continents.⁵ The acupuncture technique to treat pain involves penetrating the skin with thin, solid, metallic needles that are manipulated by the practitioner's hands (manual acupuncture) or by electrical stimulation (electroacupuncture).

This study is designed to evaluate the effect of 10 consecutive days of acupuncture in treating OA pain.

Methods

Trial Design and Participants

We conducted a case series and carried out statistical analysis of the results. The study was conducted from January 2009 to August 2009 at the Acupuncture Research Laboratory in Health Services, a research laboratory owned by the Ministry of Health of Indonesian Republic.

The criteria for inclusion in the study were aged 50 years or older, no history of previous trauma, knee X-ray showing osteophytes, gradation of pain >2 (Numeric Analogue Scale), not currently undergoing therapy in addition to acupuncture for knee pain, and willing and able to complete the study protocol. The exclusion criteria were a history of previous trauma, unable to complete the study protocol, and undergoing therapy in addition to acupuncture for knee pain.

The Ethical Committee of Health Research and Development Board approved the study. All enrolled patients gave their informed consent to participate.

Interventions

We based the acupuncture points selection from commonly used local points. The selected acupoints were bilateral Heding, Xiyan, and ST 36 Zusanli for all patients. Patients did not receive individualized acupuncture treatments. The standard acupuncture intervention entailed the insertion of disposable sterile 0.25-mm thick needles (Suzhou Huanqiu Acupuncture Medical Appliance Co., Ltd., Suzhou, China), inserted to a depth of 10–20 mm, according to the thickness of the skin and subcutaneous fatty tissues, until the De Qi sensation was elicited. All the needles were stimulated with 6805D electrical stimulator using 100 Hz continuous wave for 20 minutes. Voltage was set at a level just above the sensory threshold (minimum intensity). The treatments were carried out once a day for 10 consecutive days. Evaluations were carried out at days 0 and 10. No other interventions were administered to the patients. The acupuncture treatments were carried out by five licensed acupuncturists with more than 10 years of experience.

Outcomes

Our primary outcome measure was a change in pain changes measured using the Numeric Analogue Scale (0–10) at the end of the study (day 10).

Statistical Analysis

Comparison of knee pain before treatment and after 10 acupuncture treatments was performed using t-tests. Statistical analysis was performed using SPSS for Windows version 15.0.

Results

Recruitment of patients (n=42) took place between February 2009 and June 2009. Two patients did not complete the treatment protocol. Table 1 lists the baseline characteristics of the patients. Based on body mass index (BMI), the majority of patients were classified as normal weight (47.5%), 35% as overweight, and 15% as class I obese. Only one patient was considered underweight (2.5%). It appears that respondents with normal weight can have all degrees of OA, while OA degree III–IV is more common among obese class I respondents (Table 2). Twenty-six patients experienced a decrease in pain score of more than 2 points based on a Numeric Analogue Scale; 13 patients experienced a decrease in pain of between 1 and 2 points; only one patient did not experience a decrease in pain at all. It appears that patients with degree III–IV OA did not experience as much a decrease in pain as degree I OA patients (Table 3). The paired t-test showed significant improvement in pain scores after 10 treatments compared to baseline (P<0.05).

Table 1.

Baseline Characteristics of the Patients

Variable	Baseline data
Age group (year)
50–54, n (%)	4 (10.0)
55–64, n (%)	25 (62.5)
65–69, n (%)	5 (12.5)
≥70, n (%)	6 (15.0)
Females, n (%)	25 (62.5)
Males, n (%)	15 (37.5)
Body mass index
Underweight, n (%)	1 (2.5)
Normal, n (%)	19 (47.5)
Overweight, n (%)	14 (35.0)
Obese class I, n (%)	6 (15.0)
Degree of OA (based on x-ray)
I	2 (5.0)
I–II	7 (17.5)
II	6 (15.0)
II–III	8 (20.0)
III	11 (27.5)
III–IV	6 (15.0)

OA, osteoarthritis.

Table 2.

Cross-Tabulation Between Degree of OA (Based on X-Ray) and Body Mass Index

	Pain score decrease
Degree of OA (based on x-ray)	Underweight	Normal	Overweight	Obesity class I
I	0	1	1	0
I–II	0	4	3	0
II	0	4	1	1
II–III	0	4	4	0
III	1	4	4	2
III–IV	0	2	1	3

Table 3.

Cross-Tabulation Between Degree of OA (Based on X-Ray) and Pain Score

	Pain score decrease
Degree of OA (based on x-ray)	No change	1–2	>2
I	0	1	1
I–II	0	2	5
II	0	2	4
II–III	0	0	8
III	1	4	6
III–IV	0	4	2

Discussion

The results of our study demonstrate that electroacupuncture is effective for controlling pain in geriatric patients with OA pain of the knee.

Acupoints contain, relative to nonacupoint regions, greater densities of free (nonspecialized) nerve endings and cutaneous nerve branches, thereby increasing the conductivity of the skin above it due to low electrical resistance.⁶ Epidermal structures at these sites have low electrical resistance because they have many gap junctions, and electrical resistance is reduced due to low external calcium concentration.

Nakatani explained that acupoints are low resistance points and meridians are low resistance lines. Acupoints and meridians consist of cells arranged in series in the epidermis that are connected by gap junctions.

Acupuncture works through four dimensions: local inflammatory reaction, transduction of intercellular meridian, cutaneosomatovisceral reflex, and neural transmission to the brain (neuro acupuncture).⁸ Acupuncture will cause a local inflammatory reaction. Minor trauma caused by acupuncture will stimulate the cells to release chemicals such as bradikin, substance P, and prostaglandins. Mast cells will release histamine, heparin, and kinin proteases that will increase vasodilatation. If vasodilatation occurs in areas of inflammation, the inflammatory substances that cause pain in the area can be absorbed into the blood vessels, thereby reducing the stimulation of nociceptor and increasing the pain threshold.⁹

Acupuncture-induced reduction of chronic inflammation may also be related to the release of pituitary adrenocorticotropic hormone (ACTH) into the circulation because increased synthesis and release of anti-inflammatory adrenocortical steroids occurs after needling.^10,11

Acupuncture stimulation is also delivered by the nervous system, known as neuro acupuncture, which in principle is an acupuncture-activated pain modulation system, suppressing the transmission and perception of painful stimuli at different levels of the central nervous system.¹² The stimulation of acupuncture needles releases the neurotransmitter in the spinal cord level and higher levels through endorphinergic mechanism in the pituitary–hypothalamus complex.¹³ The released β-endorphins also enter the blood circulation causing general analgesia.

In this study, the mechanisms of acupuncture at work are a local inflammatory reaction affecting the knee, which then transmits through the afferent nerves to the posterior horn of the spinal cord. Utilization of acupuncture points in the knee area (Heding, Xiyan, and ST 36 Zusanli) is a qualified choice for the knee to reduce inflammation and increase pain threshold value.

There is considerable interest in the use of acupuncture as a relatively safe intervention for the management of knee OA. Other studies have used low-frequency electroacupuncture (2–8 Hz) to treat OA pain of the knee with good results.^14,15 This study used high-frequency electroacupuncture (100 Hz).

Low-frequency electroacupuncture appears to be mediated by μ and δ opioid peptide receptors. High-frequency electroacupuncture has a predominantly segmental effect on pain threshold. High -requency stimulation effects involve dynorphin and possibly non-opioid mechanism as well.¹⁶ Therefore, either low-frequency or high-frequency electroacupuncture appears to have good effect in controlling OA pain.

Limitations of the Study

The number of patients enrolled in this study is relatively small, and there was no control group.

Conclusion

In conclusion, electroacupuncture treatment is an effective and safe adjunctive therapy to conventional care for elderly patients with OA of the knee.

Footnotes

Disclosure Statement

No competing financial interests exist.

References

Scott

, Lethbridge-Cejku

, Hochberg

. Epidemiology and economic consequences of osteoarthritis: the American viewpoint. Reginster

J-Y

, Pelletier

J-P

, Martel-Pelletier

, Henroitin

. Osteoarthritis: Clinical and Experimental Aspects. Berlin: Springer, 1999; 20–38.

Brandt

, Mankin

, Shulman

. Workshop on etiopathogenesis of osteoarthritis. J Rheumatol., 1986; 13:1126–1160.

Guccione

, Felson

, Anderson

et al. The effects of specific medical conditions on the functional limitations of elders in the Framingham Study. Am J Public Health., 1994; 84:351–358.

Felson

. Treating inflammation to relieve osteoarthritic pain. Pain In Osteoarthritis. New Jersey: Wiley-Blackwell, 2009; 285–294.

Birch

. Treatment of pain by acupuncture. Contemporary Chinese Medicine and Acupuncture. Philadelphia: Churchill-Livingstone, 2002; 244–253.

Croley

, Carlson

. Histology of the acupuncture point. Am J Acupunct., 1991; 19:247–253.

Nakatani

, Yamashita

. Ryodoraku acupuncture: a guide for the application of Ryodoraku therapy. Tokyo: Ryodoraku Research Institute, 1997.

Saputra

, Sudirman

. Akupunktur Untuk Nyeri. Dengan pendekatan neurosain. Indonesia: Sagung Seto, 2009.

Fische

, White

. Medical Acupuncture: A Western Scientific Approach. London: Churchill-Livingstone, 1998.

10.

Liao

Y-Y

, Seto

, Saito

et al. Effect of acupuncture on adrenocortical hormone production. I. Variation in the ability for adrenocortical hormone production in response to the duration of acupuncture stimulation. Am J Chin Med., 1979; 7:362–371.

11.

Cheng

, Pomeranz

. Electroacupuncture elevates blood cortisol levels in naive horses; sham treatment has no effect. Int J Neurosci., 1980; 10:95–97.

12.

Cho

, Wong

, Fallon

. Neuro-Acupuncture. Scientific Evidence of Acupuncture Revealed. Los Angeles: Q-Puncture Inc, 2001.

13.

Pomeranz

, Cheng

. Suppression of noxious responses in single neurons of cat spinal cord by electroacupuncture and its reversal by the opiate antagonist naloxone. Exp Neuro J., 1979; 64:327–341.

14.

Sangdee

, Teekachunhatean

, Sananpanich

et al. Electroacupuncture versus Diclofenac in symptomatic treatment of osteoarthritis of the knee: a randomized controlled trial. www.biomedcentral.com/1472-6882/2/3. 2009 December 22.

15.

Berman

, Lao

, Langenberg

, Wen

, Gilpin

AMK

, Hochberg

. Effectiveness of acupuncture as adjunctive therapy in osteoarthritis of the knee: a randomized, controlled trial. Ann Intern Med., 2004; 141:901–910.

16.

Mayor

. Electroacupuncture, A Practical Manual and Resource. Spain: Churchill-Livingtone, 2007.