Clinical efficacy comparison of moxibustion w ith different doses for knee osteoarthritis

Wu Yi-wen (吳燚雯),DaiM ing (戴明),Chen Bi-song (陳碧松),Chen Jing (陳靜)

1Graduate School,Shanghai University of Traditional Chinese Medicine,Shanghai201203,China

2 Acupuncture-moxibustion Department,Longhua Hospital,ShanghaiUniversity of TraditionalChineseMedicine,Shanghai200030,China

Abstract

Keywords: Moxibustion Therapy; Thermal Box Moxibustion;Moxibustion Quantity; Moxa;Pain Measurement; Visual Analog Scale; Osteoarthritis, Knee

Knee osteoarthritis (KOA) is a common degenerative disease. Degenerative knee cartilage and bone loss in joint border or subchondral regions are the major changes in KOA. It can affect both men and women, and women run a higher risk than men.KOA is mainly characterized by joint pain,which is obvious in the morning and reduces after movement,and other manifestations include joint swelling, stiffness or even deformity, ending up as functional disorder or disability.With a high incidence rate,KOA mostly affects the m iddle-aged and elderly population.The prevalence rate of KOA can reach 50% in population over 60 years old, and as high as 78% in those over 70 years[1]. It not only affects patients' quality of life, but imposes grave economic burden on society.

The cause of KOA remains unclear. Currently, Western medicine treatment for KOA aims to alleviate symptoms.Moxibustion in traditional Chinese medicine (TCM) has the merits of warm ing meridians,promoting qi and blood flow and strengthening healthy qi, and has been proved effective for KOA[2]. Dose is an important factor in moxibustion treatment[3]. Although progresses have been made in moxibusition treatment for KOA,the relationship between moxibustion dose and efficacy remains unclear. This study was to observe the efficacy between different moxibustion doses 20 m in versus 40 min, for KOA, and explore the adequate moxibustion dose in KOA treatment, to set base for moxibustion quantity research. The report is now given as follows.

1 Materials and Methods

1.1 Diagnostic criteria

1.1.1 Diagnostic criteria of Western medicine

According to the diagnostic criteria in theGuidelines for Diagnosis and Treatment of Osteoarthritis(2007)[4]formulated by the Chinese Orthopedics Association:①repeated knee pain in the past one month; ②X-ray (standing position)exam ination show ing narrowing of the joint space,subchondral bone sclerosis and/or cystic changes, formative osteophytes;③ synovial fluid (at least 2 times) clear, sticky, white blood cell(WBC) count ＜2 000/m L;④ m iddle-aged patients(≥40 years);⑤morning stiffness≤30 m in;⑥crepitus on active motion.Comprehensive consideration of clinical,laboratory and X-ray exam inations,KOA can be diagnosed w ith①+② or ①+③+⑤+⑥ or ①+④+⑤+⑥.

1.1.2 Classification of imaging exam ination

The severity of KOA was classified by X-ray w ith reference to the Kellgren-Law rence system[5]. Grade 0:no radiographic features of OA; grade 1: suspicious joint space narrowing (JSN) and possible osteophytic lipping;grade 2:definite osteophytes and possible JSN on anteroposterior weight-bearing radiograph;grade 3:multiple osteophytes,definite JSN,sclerosis,possible bony deform ity; grade 4: large osteophytes, obvious JSN,severe sclerosis and definite bony deform ity.

1.2 Inclusion criteria

Conform ing to the above Western medicine diagnostic criteria for KOA;conform ing to the Kellgren-Law rence system grade 0 to 3;aged 40-75 years old;didn't receive any Chinese or Western treatment w ithin 1 month; able to accept the treatment and w illing to participate and sign the informed consent.

1.3 Exclusion criteria

Patients w ith unconsciousness,unable to express subjective symptoms; mental illness or other cognitive disorders;patients w ith acute joint damage;patients w ith knee joint tuberculosis,tumor or rheumatoid arthritis;coupled with severe primary cardiovascular,hepatic, renal, digestive, hematopoietic system diseases;pregnant women and lactating women.

1.4 Elim ination and shedding

The patients who didn't meet the inclusion criteria but were included by m istake;received other medications during the study which may affect the result evaluation; aggregation of disease which required other treatment methods;experienced serious complications or adverse events, and failed to follow the treatment; quitted the research automatically or poor compliance.

1.5 Statistical methods

The data were processed using the SPSS version 21.0 software. Measurement data that conformed to normal distribution were described as mean± standard deviation(±s).Paired samplet-test was used for intra-group comparison, and independent samplet-test was carried out for inter-group comparison.Measurement data that didn't conform to normal distribution were described as median (lower quartile,upper quartile)[M(QL,QU)],and exam ined by non- parametric test during intra-group and between-group comparisons. The comparisons of count data and rate were performed by non-parametric test.P＜0.05 indicated statistical significance.

1.6 General data

A total of 68 subjects,adm itted to Acupuncture Department of Longhua Hospital, Shanghai University of Traditional Chinese Medicine between May 2018 and February 2019, were enrolled. A random number table was used to create a random ized distribution card containing serial numbers, random numbers and groups.Patients were random ly assigned with cards according to the order of treatment, and were random ly assigned to a 20-m inute moxibustion group or a 40-minute moxibustion group, with 34 cases in each group. During the study,4 patients in the 20-m inute moxibustion group and 3 patients in the 40-m inute moxibustion group were lost to follow-up, and a total of 61 patients completed the trial. Between-group comparisons of the gender, age, course and X-ray classification showed no statistical significance(allP＞0.05),indicating the comparability.Please check Table 1 and Table 2 for details.

Table 1.Com parisons of the gender, age and course between the two groups

Table 2.Comparison of the X-ray classification (case)

2 Treatment Methods

2.1 20-m inute moxibustion group

Points: Dubi (ST 35), Neixiyan (EX-LE 4) and Heding (EX-LE 2).

Method:The locations of points referred theNomenclature and Location of Acupuncture Points(GB/T 12346-2006)[6].The patient took a supine position w ith a wooden moxibustion box put on the knees. The moxibustion stick (Hanyi Brand, 18 mm in diameter) was placed into the box and then ignited towards the three points above. The ignited end was placed about 3 cm away from the skin in the first place,and then adjusted the distance to make the patient feel warm instead of burning.Twenty m inutes for each point (about 3 g moxa stick) in each treatment, 3 times a week.The effect was observed after 4 weeks of treatment.

2.2 40-m inute moxibustion group

The same points,moxibustion manipulation and treatment course as those in the 20-m inute moxibustion group were adopted, while 40 m in for each point (about 6 g moxa stick) in each treatment.

3 Observation of Therapeutic Efficacy

3.1 Observation items

3.1.1Visualanalog scale(VAS)

Used a straight 10-centimeter line,w ith one end marked ‘0', indicating no pain with 0 point; the other end w ith ‘10', representing extreme pain and 10 points.The patient marked a number on the straight line according to his or her feeling of pain, and this number was the VAS score.

3.1.2 Western Ontario and M cMaster Universities osteoarthritis index (WOMAC)

WOMAC scale evaluates the structure and function of the knee joint from three aspects: pain, stiffness, and physical function of the joints,including 24 items.It ranges from 0 to 96 points, a higher point indicating a more serious condition.

3.1.3 TCM symptomsscore

Based on theGuiding Principles for Clinical Study of New Chinese Medicine[7],the severity of symptoms were evaluated as 4 grades. Each symptom (including joint pain, swelling, stiffness, motor difficulty, cold-pain,burning-pain, soreness and fatigue, malformation) was scored 0-3 points,a higher point indicating a more serious condition.

3.2 Evaluation criteria of the clinical efficacy

The Nimodipine method was used to calculate the WOMAC total score reduction,and the criteria for clinical efficacy were based on the WOMAC total score reduction.

WOMAC total score reduction rate = (Pre-treatment total score- Post-treatment total score)÷ Pretreatment total score × 100%.

Recovery:Symptoms disappeared;WOMAC total score reduction rate ≥95%.

Marked effect:Symptoms basically disappeared;WOMAC total score reduction rate ≥70%, but ＜95%.

Improvement:Symptoms basically disappeared;WOMAC total score reduction rate ≥30%, but ＜70%.

Failure:Symptoms did not improve or even aggregated, WOMAC total score reduction rate ＜30%.

3.3 Results

3.3.1Comparison of the clinical efficacy

After treatment, there was a statistically significant difference in the total effective rate between the two groups(P＜0.05),indicating that the 40-m inute moxibustion group had a better curative effect than the 20-m inute moxibustion group (Table 3).

3.3.2 Comparisons of the VAS,WOMAC and TCM symptomsscores

After treatment, the scores of VAS, WOMAC and TCM symptoms in both groups were significantly decreased(allP＜0.05),indicating symptoms alleviation in both groups. After treatment, the scores of VAS, WOMAC and TCM symptoms in the 40-m inute moxibustion group were lower than those in the 20-minute moxibustion group (allP＜0.05), indicating a better effect in the 40-m inute moxibustion group (Table 4).

Table 3. Com parison of the clinical efficacy (case)

Table 4. Comparisons of the VAS, WOMAC and TCM symptomsscores (±s, point)

Table 4. Comparisons of the VAS, WOMAC and TCM symptomsscores (±s, point)

Note: Intra-group comparison,1) P＜0.05;inter-group comparison, 2) P＜0.05

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3.3.3 Comparisons of the component scores in WOMAC

After treatment,the scores of pain,stiffness and dysfunction of WOMAC in both groups were significantly decreased(allP＜0.05),indicating that pain,stiffness and dysfunction were all alleviated in both groups.After treatment,the scores of pain and dysfunction of WOMAC in the 40-m inute moxibustion group were lower than those in the 20-m inute moxibustion group,between-group comparisons showed statisticalsignificance(bothP＜0.05),indicating a better effect in alleviating pain and dysfunction in the 40-m inute moxibustion group(Table 5).

Table 5. Comparison of the single-item score in WOMAC [M (QL, QU), point]

4 Discussion

KOA is a degenerative osteoarthrosis disease w ith high incidence and disability rates. The cause of KOA is related to overweight, joint overload and genetic factors,but the mechanism still remains unclear.In Western medicine,treatments for KOA are oral drugs,intra- articular injection, articular flushing injection and joint replacement,while such treatments are focused on alleviating symptoms,together w ith obvious side effects[8]. For the usage of chondroitin sulfuric acid and glucosamine,doctors still remain skeptical about its effect[9-10]. Forster MC,et al[11]held that in comparison of the clinical efficacy,arthroscopic articular flushing injection therapy was insignificantly different from intra-articular injection in alleviating pain and joint functions. Knee joint replacement may lead to various complications, such as thrombus and embolism, loose and abrasive wear of the artificial joint,and joint instability. Such problem set the lim itation for the usage of Western medicine in treating KOA[12]. In recent years,more doctors conduct researches of using TCM in KOA treatment.

According to its causes and symptoms,KOA falls under Bi-impediment syndrome in TCM[13-14]. The basic cause of KOA is deficiency in the root cause and excess in the symptoms: the invasion of pathogenic wind-colddampness,retention of phlegm turbidity,and stasis blocking the meridians and collaterals are the external causes, while the deficiency of liver and kidney and insufficient healthy qi are the root causes[15].Moxibustion can warm and unblock meridians and reinforce the body to consolidate Yuan-Primordial qi[16],and thus has been commonly used as a method in treating KOA.Dai M,et al[17]found that m ild moxibustion showed a better effect in decreasing VAS and WOMAC scores,alleviating pain and stiffness symptoms, and improving quality of life in KOA patients compared with oral celecoxib capsule. The mechanism of moxibustion in treating KOA still remains unclear,though it may link with the follow ing route. First, it may decrease the levels of inflammatory factors to alleviate inflammatory reaction. For example, Zheng SG,et al[18]found that the expression of interleukin(IL)-1βwas reduced in rabbit model after moxibustion.Besides,moxibustion can also reduce the level of tumor necrosis factor (TNF).Moreover,moxibustion can inhibit cartilage cell apoptosis.For example,Li JW,et al[19]found that moxibustion had the functions including inhibiting inflammatory cell infiltration and promoting proliferation of cartilage cell, and also reducing mucus inflammation, lowering the level of nitricoxidesynthase(NOS) in serum and joint fluid.

Points in this study were located around the knee joint. Dubi (ST 35), also known as Waixiyan, is located at the lateral border of patellar ligament.It can dredge meridians and elim inate swelling and pain,and is mainly used to treat joint pain.The point Neixiyan(EX-LE 4) is located in the depression on the medial side of the patellar ligament. As an extra point, it has the functions of dispersing w ind-dampness,unblocking meridians and collaterals to stop pain, and is mainly used to treat soreness and pain around the knee joint,gonarthritis and He Xi Feng (arthrosis like crane knee).Wang Y[20]found that moxibustion at Xiyan[Neixiyan(EX-LX 4) and Dubi(ST 35)] can slow down cartilage degeneration,restrain osteophyte formation in rats w ith KOA, and the possible mechanism is the reduction of transform ing grow th factor (TGF)-βin cartilage,promoting cartilage synthesis or postponing its decomposition, so as to suppress KOA development.Heding (EX-LE 2) is located on the knee joint, in the middle depression above the patella border.It can facilitate joint and dispel w ind-cold to unblock meridian and kill pain, and is frequently used in the treatment of pain and weakness in lower extrem ities.

The clinical effect of moxibustion is closely linked w ith the accumulation of its dose. Xie H,et al[3]analyzed the relationship between the efficacy and dose of moxibustion,and found that the clinical effect was determined by the moxibustion material, method and points, while the dose had a major influence on the effect. For moxibustion, a better effect usually doesn't require a very high temperature. In general, after the temperature reaches 50 ℃, the treatment effect will not be improved by the increase of the temperature[21].Therefore, an appropriate temperature is a guarantee for the optimal treatment result instead of a high one.Currently,few researches have been conducted to investigate the dose factor in moxibustion for KOA.Moxibustion dose for KOA still lacks a uniformed standard,and 20-40 m in is most frequently used.Therefore, we treated KOA patients and divided them into a 20-m inute moxibustion group and a 40-minute moxibustion group, and applied moxibustion to Dubi(ST 35), Neixiyan (EX-LE 4) and Heding (EX-LE 2), and evaluated the clinical efficacy by WOMAC, VAS and TCM symptoms scores. This study showed a better effect in the 40-m inute moxibustion group when compared with that of 20-m inute moxibustion.Moreover, 40-m inute moxibustion also showed advantages in alleviating pain and improving motor function compared with 20-m inute moxibustion.This study is a primary exploration of the suitable moxibustion dose for KOA treatment, in the w ish of providing reference for better moxibustion treatment for KOA.

C onflict of Interest The authors declare that there is no potential conflict of interest in this article.Acknow ledgments This work was supported by Shanghai Upgrading Project for Characteristic Technology of Traditional Chinese Medicine Diagnosis and Treatment [上海市中醫(yī)特色診療技術提升項目, No.ZY(2018-2020)-ZYJS-08].Statement of Informed Consent Informed consent was obtained from all individual participants.

Received:22 January 2020/Accepted:27 February 2020