Journal of Orthopaedics

Background: Although low-energy ESWT is widely used in a variety of soft tissue disorders no precise algorithm has been accepted in the clinical practice. The application of a new generation (pneumatic) device in patients is not characterized yet.
Methods: A group of 24 patients with soft tissue chronic disorders have attended our controlled prospective pilot study. The main outcome measure was based on the patient’s subjective assessment of pain by means of Visual Analog Scale (VAS) early after ESWT.
Results: Early results of treatment by ESWT are regarded as good and significant. These results of treatment do not depend on the patient’s age and the duration of symptoms.
Conclusion: ESWT emitted by the new generation (pneumatic) device seems to be an effective, alternative, analgetic measure which may be applied as a noninvasive therapeutic method in some soft tissue chronic disorders. ESWT needs further randomised controlled clinical trials.
Key words: extracorporeal shock wave therapy (ESWT), soft tissue disorders, visual analog scale (VAS)

ESWT is a well-known method which was first introduced in the treatment of renal calculi about three decades ago (1). Later ESWT was also used in the treatment of delayed bone unions and pseudoarthroses (1). Nowadays it has become an alternative method in the management of some soft tissue complaints such as tendonitis of the rotator cuff, tennis elbow, plantar fascitis and others (2, 3, 4, 5, 6, 7).

A vast application of this method was possible due to the introduction of a new generation of devices. In our clinical trial a pneumatic ESWT device has been used.

Detailed indications, contraindications and technical parameters of ESWT in soft tissue complaints treatment are not established yet (2, 3, 4, 5, 6, 7). The aim of the study is to present our own preliminary experience with the new ESWT pneumatic device and to assess early results of its application in the treatment of chronic soft tissue disorders by means of Visual Analog Scale (VAS), the evaluation of correlation concerning patients’ age, the duration of symptoms and early results of ESWT.

The inclusion criteria were major complaints of the patients who had been treated conservatively for at least six months with no positive result.

In total 28 patients were included of which half were females. The mean age of whole group was 50.6 years (SD=12.1). The mean age of males and females were, respectively 50.2 years (SD=15.2) and 51.1 (SD=8.6).

We recruited adult patients with the following soft tissue disorders plantar fascitis (N=6), tendonitis of the rotator cuff (N=9), tennis elbow (N=5), patella tip syndrome (N=4), tibial margin syndrome (N=2), peroneal muscles syndrome (N=1) and achillodynia (N=1). The patients suffer of chronic pain in above mentioned areas for a mean time 29.3 months.

Any evidence of local inflammation or infection, local arthritis, neurological disorder, pregnancy, tumor, cardiac pacemaker or anticoagulant therapy excluded participation in the study.

We have used a standardized survey in order to evaluate patient’s status before implementation of ESWT treatment. This survey included: personal data of the patient, an evaluation of a disease, a precise anatomical localization of pain, former treatment and additional diagnostic measures (x-ray, CT, NMR).

All patients had been previously treated unsuccessfully. Twenty six of them (92.9 %) had been given medication (mostly NSAID’s), most of them twice a day. Over half of the subjects (53.6%) have been subdued to physiotherapy. Six (21.4%) had been given injections of steroids.

Extracorporeal shock waves were applied by a new generation, pneumatic device (Swiss DolorClast; EMS, Nyon, Switzerland). Common ultrasound gel was used as a contact medium between the applicator (Æ=15mm) and the skin at the point of the most intensive pain. Energy flux density – 0,16 mJ/mm2 (2,5 bar).

All the patients received during the first session 500 shock waves and then in the two sessions 2000 shock waves at 3 days intervals. All the patients completed visual analog score (VAS) in which 0 mm was no pain and 100 mm the worst imaginable pain before each ESWT session.

A group of 24 patients had completed three ESWT sessions and were evaluated and considered for the statistical analysis of an early results: plantar fascitis (N=6), tendonitis of the rotator cuff (N=8), tennis elbow (N=3), patella tip syndrome (N=3), tibial margin syndrome (N=2), peroneal muscles syndrome (N=1) and achillodynia (N=1). The mean age of this group was 50.5 years (SD=11.8). One patient withdrew after the first session because she could not tolerate the therapy, one for an unknown reason. Two subjects did not attain final session for unknown reason. A group of 15 patients were subdued to the assessment by means of VAS after six months.

A comparison of the pain levels measured by means of VAS was evaluated by ANOVA and Scheffe tests (post-hoc assessment). For each patient a relative and positive change of VAS was measured. In order to evaluate a dependency between the patient’s age, duration of symptoms and the results of the ESWT the imparametric Spearman’s test was used. A level of p<0,05 was accepted as significant.

Values of VAS before the treatment, after the first session and after the second session are shown in table 1 and 2, and in figure 1. A significant decrease of VAS was observed after every session (p<0.001).

Tab. 1: Values of VAS before the sessions (VAS1), after the first (VAS2) and the second session (VAS3)

	N	mean	SD	min.	median	max.
VAS1	24	47.92	19.14	11.00	46.00	81.00
VAS2	24	37.83	18.28	8.00	40.00	74.00
VAS3	24	27.37	18.09	0.00	27.00	75.00

Fig. 1: Values of VAS before the sessions (VAS1), after the first (VAS2) and the second session (VAS3).

	N	mean	SD	min.	median	max.
DELTA13	24	20.54	16.02	- 8.00	19.00	61.00
DELTA13%	24	42.50	28.56	- 13.11	42.22	100.00

There was no correlation between patient’s age and the result of analgetic effect measured by relative and positive method (Rs=0,1; p>0,05)

There was no correlation between the duration of symptoms and the result of treatment measured by relative (Rs= - 0,1) and positive (Rs= - 0,2) method; p>0,05)

At six months 15 out of 24 patients were assessed by means of VAS. The mean positive value of VAS was 22.7 with SD=19.7 in comparison with the mean initial values of VAS 47.9 with SD=19.1.

In a large number of reports describing the role of ESWT in the treatment of soft tissue disorders the data concerning inclusion criteria, methods of study, parameters of shock-wave as well as evaluating the outcome vary considerably. In a majority of studies electrohydraulic or electromagnetic shock waves generators were used (4, 6). Our paper concerns the new generation device which due to its mobility may be used on the outpatient clinic basis. The main advantage of this new device is a size of the cap which enables a very precise application shock wave of energy. The point of application was established according to the clinical assessment as the most painful point during palpation. Other methods of focusing were based on X-ray, NMR and CT. As a method of assessment of the treatment VAS was used, which because of its popularity seems to enable the comparison of our results with other studies (8, 9, 10). The lack of correlation of the results of treatment measured by means of VAS with the patient’s age and the duration of symptoms in the early stage seems to confirm some instant effects of ESWT on soft tissues, especially on peripheral neurons.

We are aware of the fact that our studied group of patients is very heterogeneous, there is no control group and our assessment of results is very early, we have decided to publish our paper because it is one of the first studies with the new generation (pneumatic) device and early beneficial effects of ESWT are very encouraging. We plan to enlarge our group in the next projects and start randomized studies.

On the basis of our preliminary study it seems that ESWT therapy in pattern of three sessions with respectively 500, 2000 and 2000 impulses appeared to be a useful, noninvasive method in reducing pain symptoms in patients with various soft tissue complaints with negligible side effects. The results of therapy are very good while measured by means of relative and positive VAS scale both in early post ESWT stage and in the later period (after six months).

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