A Treatment Protocol for Achilles Tendinopathy with Extracorporeal Shockwave Therapy

Summary

Achilles tendinopathy is a common musculoskeletal condition for which loading programs are currently the standard of care. However, the treatment protocols vary. We therefore propose a protocol for Achilles tendinopathy treatment using extracorporeal shockwave therapy.

Abstract

Achilles tendinopathy is a common musculoskeletal condition characterized by pain, lower muscle strength, gait abnormality, and reduced quality of life. There are two categories of Achilles tendinopathy: insertional Achilles tendinopathy and mid-portion Achilles tendinopathy. Currently, mechanical loading programs are considered the standard of care for the population with Achilles tendinopathy.

Extracorporeal shockwave therapy (ESWT) is considered a secondary conservative treatment for tendinopathy as it is effective and safe. It can be used either as a monotherapy or as part of a multimodal treatment plan. ESWT has been extensively studied in orthopedics, where it was shown to intensify fracture healing and successfully treat overuse conditions of tendons and fascia. It is believed that shockwaves have both mechanical and cellular effects that ultimately result in the repair of damaged tendinous tissue and improved function of the Achilles tendon. However, there is a lack of consistency in the literature surrounding the effectiveness, especially the protocols. Therefore, we enrolled 36 patients with a diagnosis of Achilles tendinopathy, using radial ESWT (0.48 mJ/mm², 2,000 shockwaves, 10 Hz, 1.6 bars, 2 sessions once a week). Freedom from pain was experienced by 16.7% of these participants, and there was a significant decrease in pain in all of them.

Introduction

The Achilles tendon is one of the most robust tendons in the body, yet it is highly susceptible to injuries. Tendons play a crucial role in enabling joint motion and stability by transmitting tensile loads produced by muscles onto bones¹. Tendinopathy is a concept describing chronic tendon degeneration and deconditioning, also called tendinitis². However, the exact cause of Achilles Tendinopathy² remains unclear. It is believed to result from a combination of factors, including overuse stresses, impaired blood flow, and lack of flexibility². One of the major contributors to the development of Achilles tendon injuries is the excessive load force applied during intense activities such as running, without allowing sufficient time for proper tendon repair¹. This continuous stress on the tendon can lead to the gradual accumulation of microtraumas and ultimately result in injury progression³. This highlights the importance of proper management, rest, and adequate rehabilitation periods in preventing such injuries and maintaining the health of the Achilles tendon. The diagnosis of Achilles tendinopathy relies mainly on a comprehensive patient history and clinical examination⁴. A typical symptom is the occurrence of morning stiffness or limited range of motion after prolonged inactivity, accompanied by gradually increasing pain during physical activity². Athletes often go through pain at the beginning and end of the training, with a period of decreased discomfort in between. However, since the condition worsens, even slight exertion can lead to the onset of pain, greatly affecting daily activities. In severe cases, individuals may even experience pain while at rest⁵.

The management of Achilles tendinopathy primarily involves conservative approaches, even though approximately 25%-29% of patients may eventually require surgery for the condition⁵. Cardoso et al.⁶ summarized an overview of the current treatment of Achilles tendinopathy, including medications, exercise, corticosteroid injections, platelet-rich plasma injections, manual therapy, and modalities. Among these treatments, the most widely recommended is exercise, which targets the injured tendons, especially mechanical loading exercises; eccentric exercise has been considered a better intervention. Even though it has been proven useful to decrease pain and improve function in the short term, a significant portion of patients have not responded to this strategy in a long-term study⁷, and some patients seek other treatments.

In recent years, extracorporeal shockwave therapy (ESWT) has demonstrated beneficial effects on musculoskeletal disorders and has become an effective treatment for tendinopathy^8,9. There is now increasing evidence supporting the effectiveness of ESWT for lower extremity tendinopathy¹⁰ and upper extremity tendinopathy¹¹. Originally used in urology for kidney stone treatment, ESWT has found therapeutic application in a wide range of medical and musculoskeletal conditions, making it a major innovation in the field of regenerative medicine¹². There are two types of ESWT: focused shock waves and radial pressure waves^13,14; the main difference between them is their physical characteristics. As a result, they stimulate diverse regenerative biological reactions in musculoskeletal tissue, activating proteins that play a role in chondroprotection¹⁵, vessel regeneration^16,17, reducing inflammatory¹⁸, anti-apoptosis¹⁹, immunomodulation²⁰, neurophysiological mechanisms, and pain relief¹¹. ESWT also triggers the initiation of the healing processes, which facilitates the proliferation, differentiation, and migration of diverse cell types such as mesenchymal stem cells, endothelial cells, fibroblasts, and tendon cells. Additionally, it promotes the synthesis of collagen²¹. Furthermore, ESWT has been found to induce several tendon-specific responses that facilitate the healing progress²².

Although radial-ESWT is considered effective in Achilles tendinopathy treatment, there are various reports on the technique of radial ESWT without any consensus on the parameters. In this paper, we present a detailed treatment protocol for treating Achilles Tendinopathy using ESWT.

Protocol

This protocol was approved by our institution's human research ethics committee and received informed consent from the subjects. Individuals older than 18 years old, both sexes, with a definite diagnosis of Achilles tendinopathy, were enrolled. Participants who received ankle surgery recently or were diagnosed with any conditions that were contraindications to the treatment were excluded.

1. Patient evaluation

1. Clinical examination
   1. Before implementing the protocol, clinically evaluate the patients to rule out other regions that may cause symptoms. Obtain a thorough medical history, including the history of treatments, and rule out any contraindications (e.g., pregnancy, placement over major blood vessels and nerves, presence of pacemakers or other implanted devices, open wounds, joint replacements, epiphysis, blood clotting disorders, active infection, presence of cancerous tissues, impaired mental status of the patient, and/or unwillingness to cooperate).
2. Physiotherapy examination
   1. Perform a physical examination to assess the condition being treated through inspection and palpation and evaluate the range of motion (both active and passive) of the ankle.
   2. Obtain the baseline information of the patient, such as pain and range of motion, using the Victorian Institute of Sports Assessment-Achilles (VISA-A) and/or American Orthopedic Foot and Ankle Society (AOFAS) Hindfoot score as outcome measures^5,9,12.

2. Application technique

NOTE: Before starting the procedure, check whether all the equipment listed in the Table of Materials is available.

1. Place the patient in a comfortable prone position, with the target area exposed. If the patient is found to have significant tenderness in the calf muscles during the physical examination, expose the lower leg.
2. Locate the area that requires treatment after the physical examination and mark these points using a felt tip pen.
3. Choose a transmitter based on the desired depth of penetration for the treatment point (Figure 1). Use the conductor R 15 for tendinopathy and D20 (in this study, with energy 0.48 mJ/mm²) for tendinopathy and the trigger point of the deep muscle. Inform the patient that regular sounds made by the transmitters may be heard during treatment.
4. Dry the skin thoroughly and apply an adequate amount of gel to the target area as a coupling agent.
   NOTE: Apply the gel adequately to the treated area and ensure that the shock wave conductors are in contact with the skin surface throughout the treatment.
5. As the operator, work in an ergonomic position (Figure 2) to optimize comfort and efficiency. To obtain the best treatment results, ensure good contact between shock wave transducers and the patient's skin during treatment.
   NOTE: Do not press the treatment output handle tightly to the affected part; this will not help the treatment.
6. Device setup
   1. Press the Power On/OFF button or touch the liquid crystal display (LCD).
   2. Inspect parameter options on the display and press the buttons directly on the LCD to make a selection. Adjust the parameters using the up and down buttons.
   3. Press the Pause or Stop buttons located on the Operator Interface to stop the output.
      NOTE: Information on the intensity and number of pulses given during the treatments can be obtained from the LCD.
7. Editing the treatment screen and parameter modification
   1. Press the edit button and wait for the Edit treatment screen to display. Increase and decrease the parameters on the Edit treatment screen by pressing the up and down buttons as needed during the treatment process based on the patient's tolerance and response.
   2. Select the intensity to be used (1.6 Bar in this study). Start at a lower intensity of the therapy, then gradually increase the intensity as high as the patient can tolerate. The recommended intensity range is between 1.4 Bar and 3.0 Bar²³.
   3. Set the frequency of the treatment (10 Hz here). Choose a frequency between 8 Hz and 15 Hz for the treatment²⁴.
   4. Establish the desired number of shocks to be applied (2,000 in this study); the number of shocks per treatment is 800-3,000^23,24.
8. Begin the treatment by pressing the Start button on the User Interface and activate the handpiece by pressing the trigger button on the handpiece. The unit begins emitting radial pressure wave energy. During the treatment, maintain the contact between the conductor and the skin tissue, and move the handle by drawing a small circle.
9. Stopping and pausing therapy
   1. Stop the therapy by pressing the Stop button on the User Interface.
   2. Press the Pause button on the User Interface or the trigger button on the handpiece to pause the therapy at any time.
10. Plan three sessions spaced 1 week apart²⁵.

3. Posttreatment protocol

1. Remove any residual coupling gel from the treated area.
2. After treatment, ask the patients to apply ice for no more than 10 min if they feel discomfort. In some cases, patients may suffer intense pain because of an acute resorption process caused by the shock waves.
3. To consolidate the therapeutic effect, if necessary, combine ESWT with other physical therapy treatments, such as modalities and exercise. Recommend that the patient do muscle exercise after treatment, especially eccentric exercise^23,24.
4. Ask the patients to report and look for side effects such as reddening, swelling, pain, hematoma, petechiae, red spots, and skin lesions after previous ESWT; these effects usually appear within a few days after shock wave therapy. Ensure that the symptoms disappear completely before starting treatment.
5. If there are no changes in outcome measures, advise the patients to seek a new treatment module or move on to invasive procedures.

Results

A retrospective study of patients with Achilles tendinopathy was performed on individuals older than 18 years old, with a definite diagnosis of Achilles tendinopathy. Exclusion criteria were recent ankle surgery or any condition that is a contraindication of ESWT.

This study included 36 participants. diagnosis with Achilles tendinopathy, 18 females and 18 males. Of these patients, their average age was 43.7 years, ranging between 18 and 64 years. All the patients complained of pain; 11 out of ...

Discussion

This protocol outlines a standardized treatment protocol for Achilles tendinopathy utilizing radial-ESWT to reduce pain and improve lower extremity function and mobility. It is crucial to closely monitor the patient's response during treatment to avoid any potential adverse effects. In our study, we observed positive results when we used low-energy ESWT plus eccentric exercise. Table 2 lists the intervention methods and major conclusions of studies on the effectiveness of ESWT for Achilles tendinopat...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
ESWT device	Chattanooga	Intelect RPW 2074-INT	incorporate touch screen technology to ensure a high degree of simplicity. The easy-to-use menu-drive user interface guarantees reliable selection of all necessary parameters for treatment set-up as well as during patient treatment.
Gel	KeppLer	KL-250 type II	In order to obtain the best treatment results, it is necessary to ensure good contact between shock wave transducers and the patient's skin during treatment.
Handpiece	Chattanooga	D-ACTOR Apllicator	The handle of the therapeutic apparatus can be used with a variety of transmitters, each of which is specially designed to achieve optimal efficacy.
Mark pen	general
Tissue	general
transmitters	Chattanooga	R15,D20	Each type of transmitter has its own unique therapeutic effect and scope of application.In our study, we use R15 and D20.