This prospective, randomized control study was performed between February 2013, and June 2014 at the Department of Orthopadedics of the Third Hospital affiliated with Zhejiang Chinese Medical University, Hangzhou, China. The prospective data included in this study were obtained as part of the routine care of the patients and were part of their medical records. All patients in this study were screened using the predetermined sealed-envelope method. A clinical diagnosis of LE was made on the basis of a history of lateral elbow pain that was triggered or exacerbated by wrist extension generally or during specific activities and point tenderness of the lateral epicondyle[20]. The duration of LE in each participant was more than 3 months, and the participants were over 18 years old. All patients underwent a standard radiographic examination before treatment, and no patients had been treated with injections during surgical intervention or other treatments that would affect the condition for 6 months. The exclusion criteria were a history of previous elbow injury, a history of surgery, the presence of coexisting neck or thorax pathology, the presence of a tumour, infection or ganglion in the region of the elbow, elbow arthritis, and a history of clotting disorder or diabetes mellitus. The trial was explained to the patient by an investigator who provided the procedures and aim of the study. The study was approved by the Health Ethics Research Board of the Third Affiliated Hospital of Zhejiang Chinese Medical University.
Sample size calculation
The primary efficacy parameter was the change in Mid-Atlantic Shoulder and Elbow Society (MASES) scores from baseline to the end of treatment after 2 weeks. According to our preliminary test and a previous study[10,18], a sample size of 45 patients per group provided 80% power to detect a clinically meaningful difference between group I and group II at an alpha level of 0.05 (2-tailed test). Approximately 39 participants in each group were calculated to be needed. In addition, to account for a dropout rate of 10%, at least 45 participants were enrolled in each group. Ultimately, the study population consisted of 90 patients with a diagnosis of LE who were randomly divided into two groups: group I (45 cases) participants were treated with a specially designed needle (acupotomy), and group II (45 cases) participants were treated with corticosteroid injection.
Classification of tennis elbow
Extra-articular type tennis elbow was classified as pain that appeared in the lateral region of the elbow that was aggravated by working and that could be alleviated at rest. Additionally, in some of these participants, the tenderness was limited to the outside of the humerus condyle, elbow motion was unrestricted, Milton's character and wrist extensor strain test results were positive, and bone hyperplasia of the outside humerus condyle was present on the X-ray. Intraarticular type tennis elbow was defined as pain that appeared within the humerus oar joint during passive activities. In these patients, the elbow pain was more severe and could not be alleviated at rest. Tenderness was mainly limited to humerus oar joint spaces. A region of synovial hypertrophy could be observed, and elbow motion was restricted. Humerus oar joint hypertrophy of the synovial shadow could be observed on X-ray. Mixed type tennis elbow was the diagnosis when the above characteristics of both classifications or other symptoms were present.
Treatment protocols and procedure
We treated LE patients using a specially designed needle (Hanzhang specially designed needle (Huaxia Meditech 53 Inc., Beijing, China)) that was6 mm in diameter and 50 mm long. It was streamlined and solid. The tip was planus to facilitate its insertion into the skin. The width of the blade was 0.6 mm to release the tendinous tissue, which was safer and produced less damage (Fig. 1).
Fig. 1. A clinical photograph of the specially designed needle and the acupotomy treatment at the lateral epicondyle.
In the outpatient department, after confirmation of the clinical diagnosis, patients in group I were treated with a specially designed needle. The technique was as follows (Fig. 1). The point of pain was located at the lateral epicondyle of the humerus by palpation. The local area of the skin was cleaned, and 1% plain lignocaine was injected using a 25-gauge needle. For patients with extra-articular type tennis elbow, the specially designed needle was inserted through the skin at 90°, and the bevel of the needle was placed parallel to the long axis of the forearm muscle fibres, blood vessels, and nerves. The cutting and peeling technique was performed close to the bone and repeated twice. At the same time, an assistant documented upper limb flexion of elbow, flexion of the wrist, pronation and the activities of the elbow. For patients with intraarticular type tennis elbow, the specially designed needle was inserted through the skin at 90°, and the bevel of the needle was placed transverse to the humerus oar joint spaces. The transverse oscillation technique was performed along the joint space and repeated 3~4 times. At the same time, an assistant recorded upper limb flexion of the elbow, flexion of the wrist, pronation and activities of the elbow. For patients with mixed type tennis elbow, according to the specific signs, the above treatments were used and combined at the actual pressure point. Patients in group II were administered special injection therapy. The injection therapy consisted of a single injection of 1 mL of diprospan and 2% lignocaine hyrochloride made up to a volume of 2 mL, which was injected into the symptomatically tender region of the common extensor origin. The treatments of the two groups were administered once a week and three times total as a course of treatment.
Clinical evaluation
Patients were asked to evaluate the overall pain using a visual analogue scale, and tenderness and grip strength assessments were used to evaluate changes in the symptoms. The Nirschl staging system was used to evaluate elbow function. With reference to Nirschl staging [21], the criteria used to assess the curative effect of tennis elbow treatment were divided into seven grades. Outcome assessments were performed by the investigator before randomization and 6 weeks, 12 weeks, 24 weeks and 48 weeks after the start of the treatment. Patients were asked to evaluate the pain using a visual analogue scale (VAS 0: no pain; VAS 10: extreme pain) at rest, during daily activities, and during sports or work in specific situations. Tenderness was recorded with an M-tone digital pressure tester (Tianjin Ming Tong Century Technology Co., Ltd.) before and after the treatment, which produced the stress of tenderness. The pain-free grip strength (PFGS) was measured in kilograms when patients gripped a load grip strength apparatus (cixi ZongHanYan shun Plastic hardware factory production) before and after treatment while patients were in a seated position. The testing procedure consisted of the patient standing with the shoulder adducted to 0° and in a neutral position and with the elbow extended to 90° and the forearm pronated. The patients were instructed to slowly squeeze the dynamometer and to stop the instant any discomfort was first felt. The results of three attempts separated by 1 minute intervals were recorded, and the mean value in kilograms was calculated.
Elbow function was evaluated according to the Nirschl system, which consists of seven phases in ascending level of the severity of pain (Table I). It ranges from phase 1 (mild pain with exercise, resolves within 24 hours) to phase 7 (constant pain at rest, disrupts sleep).
Statistical analysis
All data were analysed by a blinded statistician using the SPSS (Statistical Product and Service Solutions) statistical package program (version 17.0, SPSS Inc., Chicago, Illinois, United States) at a location that was different from the third clinical research institute of Zhejiang Provincial Hospital of Chinese medicine. Data were analysed using a paired samples t test and repeated-measures analysis of variance (ANOVA). All patients randomized to each group were included in the analysis, and the data analysis was conducted using two-sided significance tests at the 5% significance level. Quantitative data with continuous variables are expressed as the mean ± SD. Differences between groups were analysed with one-way ANOVA, and a t test was used for comparisons of two independent samples. Hierarchical data were ranked and assessed, with a P value of < 0.05 indicating that the difference was statistically significant.