Acupotomy for Osteoarthritis of the Knee; A Systematic Review and Meta-Analysis
Article information
Abstract
The purpose of this study was to evaluate the effectiveness and safety of acupotomy for the treatment of patients with knee osteoarthritis. There were 9 databases searched to retrieve randomized controlled trials until August 3, 2019 regarding acupotomy versus conventional Western medicine, conventional Western medicine treatment with and without acupotomy, and Korean medicine treatment with and without acupotomy, and meta-analysis was performed. Of 303 potentially relevant studies retrieved, 43 were systematically reviewed. All studies were conducted in China. Effective rate, visual analogue scale, and Western Ontario and McMaster Universities Osteoarthritis index were used as the evaluation scales. The Ashi point was selected most frequently. In all studies, the intervention group was more effective than the control group. Meta-analysis revealed that acupotomy showed statistically significant beneficial results. Although acupotomy had a beneficial effect on knee osteoarthritis, the risk of bias of the included studies was not low. The majority of the results from the evaluation scales used were highly heterogeneous (> 50%) which reduced confidence in the estimation of effect, or had a small sample size. Further clinical research and development is required in the future.
Introduction
Osteoarthritis (OA) is a joint disease caused by degeneration of the articular cartilage, abrasion, and proliferative changes in the osteocartilage such as osteophyte formation at the joint margins, or sclerosis of the subchondral bone, and occurs in people over 75 years [1]. The chief presumed cause of OA is mechanical stress on the joints, due to aging, being overweight, weakening of the joint supporting muscles, and damage to the peripheral nerves. The knee, which significantly supports the weight of the body, is one of the main sites of OA [2].
The treatment of OA is primarily focused on relieving pain and stiffness, and increasing mobility [3]. Conservative treatment involves many pharmacological therapies such as nonsteroidal anti-inflammatory drugs, hyaluronic acid, steroids, and glucosamine [4]. However, serious side effects including bleeding, perforation of ulcers, and gastrointestinal issues have been reported [5,6]. Therefore, non-pharmaceutical therapies for knee OA are increasingly being preferred. The European Rheumatology Society proposes acupuncture as one of the non-pharmaceutical treatments for OA [6]. Acupotomy, a type of acupuncture, is a relatively new therapy which combines oriental medical acupuncture and modern surgical therapy. Acupotomy has surgical treatment advantages such as peeling or cutting the adhesions of soft tissues [7]. Acupotomy is easy to perform, results in less tissue damage, less infection, and shorter process and treatment time compared with conventional surgery and can be applied to various musculoskeletal areas [8].
The purpose of this study was to evaluate the effectiveness and safety of acupotomy for the treatment of patients with knee OA. Data was collected on the effects of acupotomy in patients with knee OA and a systematic review and meta-analysis was conducted to assess acupotomy versus conventional Western medicine, conventional Western medicine treatment with and without acupotomy, and Korean medicine treatment with and without acupotomy. Based on the results, we aimed to objectively provide evidence-based medical advice for the treatment of patients with knee OA.
Materials and Methods
Search strategy
There were 9 databases (PubMed, EMBASE, the Cochrane library, Citation Information by National Institute of Informatics, China National Knowledge Infrastructure, Korean Medical Database, Korean Studies Information Service System, National Digital Science Library, and the Korean database Oriental medicine Advanced Searching Integrated System) searched for articles published until August 3, 2019.
Search words were based on the “Medical Subject Headings.” The subject-related terms were searched by combining arthritis, OA, knee joint, degenerative arthritis, knee, acupotome, acupotomy, needle knife, cutting needle, needle scalpel, and randomized controlled trial (RCT). The search was modified and used according to the context and language of each database.
Eligibility criteria
Inclusion criteria
This study included only RCTs that applied acupotomy for the treatment of knee OA.
Exclusion criteria
Literature reviews, case reports, observational research, animal experiments, management studies after surgery (e.g., knee replacement), studies on treatment methods that are not commonly practiced in Korean medicine, and those conducted on children and adolescents were excluded. Studies in which the control group was inappropriate (e.g., acupotomy versus acupuncture) were also excluded.
Data extraction and quality assessment
All articles were independently extracted and assessed by 2 reviewers. Discrepancies were solved by discussion between the 2 reviewers, and in cases where no consensus was reached, a 3rd reviewer with similar qualifications was consulted. The Cochrane Collaboration tool for RCTs was used to assess the risk of bias of the studies retrieved.
Statistical analysis
Meta-analysis was performed using Review Manager 5.3 (Copenhagen: The Nordic Cochrane Center, The Cochrane Collaboration, 2014) when quantitative analysis was possible from the extracted results. Analysis was performed by categorizing the data according to the comparison group or the outcome variable. The outcome variable was presented as mean difference (MD) or standard mean difference (SMD) using inverse variance analysis in cases of continuous data. In cases of binary data, the outcome variable was presented as risk ratio (RR) using Mantel-Haenszel analysis. A fixed effect model was used for the analysis model. In addition, subgroup analysis was conducted, if required depending on the study design (type of comparison group, treatment period and frequency, amongst other parameters).
Results
Study selection results
There were 700 studies retrieved from the database search. Of these, 56 duplicate articles were removed and primary screening was conducted on the 644 remaining articles by reading the titles and abstracts. Based on the text review there were 180 eligible articles, 133 were excluded. In addition, 4 of these 47 articles in the qualitative synthesis were excluded because they were not included in the quantitative synthesis. There were 43 articles included in this review. The process of selecting the articles is illustrated using the flow chart of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (Fig. 1), and details of selected articles are summarized in Table 1 [9,11–51]. Acupotomy is referred to as different names, such as needle-knife, small needle knife, stiletto needle, as well as acupotomy [10].

A flow diagram of articles selected for review according to the PRISMA.
OA, osteoarthritis; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses; RCT, randomized controlled trial.
Characteristics of the selected studies
Year and country of publication
Ten studies were conducted in 2017, 8 in 2015, 6 in 2013, 3 each in 2016, 2018, and 2019, 2 each in 2009, 2010, and 2012, and 1 each in 2006, 2007, 2011, and 2014. All 43 selected studies were conducted in China.
Sample size
The total number of patients included in all the RCTs included in this review was 4,268. In each study, the total number of patients in both the intervention and control groups was at least 40 and at most 197. Specifically, there was 1 study that included less than 50 patients, 21 studies with 50–100 patients, 15 studies with 100–150 patients, and 6 studies with more than 150 patients.
Duration and frequency of treatment
Sixteen and 26 studies reported treatment duration of less than 4 weeks, and more than 4 weeks, respectively. There was 1 study that reported 8 weeks of treatment [47].
The treatment sections were proportional to the duration of treatment. There were 22 studies with less than 5 sessions of treatment, 17 studies with 5–10 sessions, and 1 study with more than 10 sessions. Three studies did not report the exact number of treatment sessions [40,44,47].
Acupoints
Analysis of the selected acupoints in the intervention group revealed that, the Ashi point was the most frequently selected (30 times in the 43 studies). In addition, acupoints representing the medial and lateral collateral ligaments of the knee, and the patellar ligament, Ex-LE 2, Ex-LE 4, Ex-LE 5, SP-9, SP-10, SP-34, GB-34, and ST-35 were selected frequently.
Evaluation index
The most commonly used evaluation index was the effective rate which was used in 37 studies. The visual analogue scale (VAS) was used as the evaluation index in 16 studies while the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index was used in 11 studies.
Analysis of adverse effects
Only 3 studies reported adverse effects. In the study by Liu [12], symptoms such as fainting during treatment, increased pain, palpitations, and increased blood pressure after acupotomy were reported. However, these resolved within 3 days of acupotomy treatment without any intervention [12]. Similarly, Wu and Li [27] reported increased pain and swelling following the treatment. Chen [46] reported the patients had a bitter taste in their mouth after acupotomy treatment. No adverse events were reported in 5 studies, while no serious events were reported in 2 studies. There was no information regarding adverse effects in 33 studies.
Risk of bias assessment
Random sequence generation
There were 20 low-risk studies in which random assignments were performed using random number tables. Twenty-two studies were classified as unclear risk of bias. Of these 22 studies, 18 were classified as an unclear risk, since only “random assignment” was mentioned without any explanation regarding the specific method of randomization. There was no information regarding random assignment in 3 studies, and patient allocation in 1 study was based on the medical record number. Only 1 study had a high risk of bias, because the assignment was based on the time and order of visits [43].
Allocation concealment
The risk of bias was low in 2 studies [19,37]. In these studies, opaque sealed envelopes were assigned a serial number, and the assignment order was maintained. The remaining studies were classified as unclear risk, because there was no information regarding allocation order concealment.
Blinding of participants and personnel
All 43 studies were classified as high risk. This is because there was no information regarding blinding of the participants and personnel.
Incomplete outcome assessment
Forty-two studies were classified as low risk. Only 1 study had an unclear risk of bias because 4 of the 60 patients in the intervention group and 8 in the control group dropped out, and the reason was not stated [39].
Selective reporting
All studies followed specific protocols and were therefore considered low risk.
Other bias
All 43 studies were classified as low risk, because there was no risk of additional bias.
Meta-analysis
Acupotomy versus conventional Western medicine
Meta-analysis performed on the outcomes of the VAS revealed a significant reduction in pain with a MD of −1.85 (95% CI −1.92, −1.79, p < 0.001). Four studies included in this analysis did not reveal significant heterogeneity (I2 = 73; Fig. 2). Analysis of the WOMAC index total confirmed significant improvement in function with a MD of −17.86 (95% CI −20.06, −15.66, p < 0.001). Two studies included in this analysis were heterogeneous (I2 = 98%; Fig. 3). Analysis of the WOMAC index for pain revealed a significant reduction in pain with a SMD of −0.91 (95% CI −1.11, −0.70, p < 0.001). Five studies in this analysis were confirmed to have heterogeneity (I2 = 90%; Fig. 3). Analysis of the WOMAC index for stiffness demonstrated improved strength with a SMD of −0.93 (95% CI −1.17, −0.70, p < 0.001). Five studies in this analysis were confirmed to have heterogeneity (I2 = 98%; Fig. 3). Analysis of the WOMAC index for function confirmed improvement in body function with a SMD of −0.87 (95% CI −1.09, −0.64, p < 0.001). Four studies in this analysis were heterogeneous (I2 = 95; Fig. 3). Analysis of the effective rate revealed a significant improvement in symptoms with a RR of 1.15 (95% CI 1.10, 1.20, p < 0.001). Sixteen studies included in this analysis were not heterogeneous (I2 = 18; Fig. 4).

The meta-analysis of acupotomy versus conventional Western medicine (VAS).
VAS, visual analog scale.

The meta-analysis of acupotomy versus conventional Western medicine (WOMAC total, pain, stiffness, function).
WOMAC, Western Ontario and McMaster Universities Arthritis index.
Results of conventional Western medicine treatment with and without acupotomy
Meta-analysis performed on the outcomes of the VAS scores revealed a significant reduction in pain with a MD of −0.58 (95% CI −0.65, −0.52, p < 0.001). There were 7 studies included in the analysis that confirmed heterogeneity (I2 = 98%; Fig. 5). Analysis of the WOMAC index for pain confirmed a significant reduction in pain with a MD of −3.32 (95% CI −3.81, −2.83, p < 0.001). The effect of improving performance (by reducing pain) was confirmed. There was only 1 study included in the analysis, and the heterogeneity could not be confirmed (Fig. 6). Analysis of the WOMAC index for stiffness revealed a MD of −1.88 (95% CI −2.22, −1.54, p < 0.001). The effect of improving function (by reducing stiffness) was confirmed. There was only 1 study included in the analysis and heterogeneity could not be confirmed (Fig. 6). Analysis of the WOMAC index for function demonstrated a significant functional improvement with a MD of −7.13 (95% CI −7.74, −6.52, p < 0.001). Two studies were included in this analysis and there was no significant heterogeneity (I2 = 0%; Fig. 6). Analysis of the effective rate revealed that a significant improvement in symptoms was achieved with a RR of 1.35 (95% CI 1.28, 1.43, p < 0.001). There were 7 studies included in the analysis that confirmed heterogeneity (I2 = 88%; Fig. 7).

The meta-analysis of conventional Western Medicine treatment with and without acupotomy (VAS).
VAS, visual analog scale.

The meta-analysis of conventional Western medicine treatment with and without acupotomy (WOMAC pain, stiffness, function).
WOMAC, Western Ontario and McMaster Universities Arthritis index.
Korean medicine treatment with and without acupotomy
Meta-analysis performed on the outcomes based on the VAS scores confirmed a significant reduction in pain with a MD of −1.45 (95% CI −1.78, −1.13, p < 0.001). Five studies were included in this analysis, all of which were not significantly heterogeneous (I2 = 54; Fig. 8). Analysis of the WOMAC index total confirmed significant functional improvement with a MD of −7.66 (95% CI −9.91, −5.41, p < 0.001). There was only 1 study included in the analysis, and heterogeneity could not be confirmed (Fig. 8). Analysis of the effective rate revealed significant improvement in symptoms with a RR of 1.16 (95% CI 1.11, 1.21, p < 0.001). Ten studies were included in this analysis and there was no significant heterogeneity (I2 = 9%; Fig. 8).
Discussion
In this review acupotomy versus conventional Western medicine, conventional Western medicine treatment with and without acupotomy, and Korean medicine treatment with and without Acupotomy was assessed. There were 19 studies identified which compared acupotomy with conventional Western medicine treatments. There were 14 studies which compared the outcomes of patients in the intervention and control groups treated with conventional Western medicine plus acupotomy, and conventional Western medicine alone. Meloxicam, sodium hyaluronate, triamcinolone acetonide, lidocaine, vitamin B12, glucosamine HCl, carboxymethyl chitin, voltaren, and betamethasone were used, and arthroscopic surgery was performed in patients in the Western medicine group. Among them, sodium hyaluronate was the most commonly used agent. The remaining 10 studies compared the intervention group, wherein patients received combined acupotomy with Korean medicine treatment with the control group wherein only Korean medicine treatment was performed. Warm needle, cupping therapy, electroacupuncture, herbal capsules which nourish the kidney and strengthen the muscle, Jibaikjihwangtang, shortwave therapy, microwave therapy, and chuna were used in Korean medicine group. Among them, cupping therapy, and chuna were used most frequently.
Ashi point was the most frequently selected acupoint. Acupoints representing the medial and lateral collateral ligaments of the knee and the patellar ligament, Ex-LE 2, Ex-LE 4, Ex-LE 5, SP-9, SP-10, SP-34, GB-34, and ST-35 were frequently selected.
Effective rate, VAS, and the WOMAC index were used as the evaluation scales, and the effective rate was used the most frequently. In all studies, the intervention group showed a greater beneficial effect than the control group.
Meta-analysis revealed that acupotomy showed statistically significant beneficial results based on scores of the VAS, WOMAC index (total, pain, function), and effective rate. The combination treatment with acupotomy and Western medicine showed a significant beneficial effect on the WOMAC index (pain, stiffness, function) and VAS scores, as well as the effective rate compared with the control group, wherein only Western medicine was used. The combination treatment with acupotomy and Korean medicine showed statistically significant beneficial effects based on the VAS, WOMAC index total scores, and the effective rate compared with the control group wherein only Korean medicine was used.
Some studies reported adverse effects among patients in the acupotomy treatment group. Increased pain, swelling, palpitations, fainting, increased blood pressure, and a bitter taste in the mouth were reported. However, these adverse effects were considered mild and transient events following acupuncture [53]. Therefore, it may be considered that no serious risks are involved, except for surgical infection which would require the attention of the clinician.
Although this review confirmed that acupotomy had a statistically significant beneficial effect on knee OA, the risk of bias of the included studies was not low. In more than half of the studies, there was no clear statement regarding the method of randomization. In most studies, there was no information regarding the allocation order, concealment, and blinding of the participants and personnel. The majority of the scales were highly heterogeneous (> 50%), or the study had a small sample size which reduced confidence in effect estimation. In conclusion, the results of this study suggested that acupotomy may be an effective and safe treatment for knee OA. However, further clinical research and development is required in the future. It is essential to conduct systematic RCTs on a large sample size with low risk of bias.
Notes
Conflicts of Interest
The authors have no conflicts of interest to declare.
Funding
This study was supported by the traditional Korean medicine R&D program funded by the Ministry of Health and Welfare through the Korea Health Industry Development Institute (grant no.: HB17C0003). The funding body did not play a role in the study other than to provide funding.