Effectiveness of Reducing Tendon Compression in the Treatment of Insertional Achilles Tendinopathy (GhenTendon)

Effectiveness of Reducing Tendon Compression in the Treatment of Insertional Achilles Tendinopathy: a Randomised Clinical Trial

Insertional Achilles tendinopathy is a disabling injury that is common in running athletes. Exercise therapy is considered the best treatment option, but there is still no agreement on the modalities. For example, it is thought that compression overload may be a major cause of tendinopathy and should therefore be restricted during rehabilitation. However, this recommendation is based on expert opinion and not on hard scientific evidence. Therefore, this randomised controlled trial (RCT) will investigate whether a therapy that limits the amount of compression of the tendon during a progressive tendon-loading rehabilitation protocol actually has better outcomes in athletes with insertional Achilles tendinopathy. 28 athletes with insertional Achilles tendinopathy will be randomised into two treatment groups; (1) an experimental 12-week rehabilitation protocol in which the amount of tendon compression is limited and (2) a 12-week control rehabilitation protocol in which the amount of tendon compression is not limited and is rather high. Both treatments consist of supervised progressive tendon-loading exercise therapy and patient education. In addition, the experimental group will also receive heel inserts to limit the amount of dorsiflexion during sports or daily activities. At baseline, at 12 weeks (end of intervention) and at 24 weeks (follow-up), pain, functionality, structure and intratendinous pressure will be determined.

Achilles tendinopathy is a debilitating injury that is common among athletes, especially those involved in running sports. Around 30% of all runners exhibit Achilles tendinopathy with an annual incidence of 7-9%. Of these patients, roughly one-third will have insertional Achilles tendinopathy (IAT). Several mechanisms are considered to play a role in the aetiology of Achilles tendinopathy, yet a prominent role seems present for excessive overload. Traditionally, the nature of this overload is thought to be purely tensile. However, the Achilles tendon can also be exposed to compressive loads at the insertion when the tendon wraps around the posterior prominence of the calcaneus during dorsiflexion of the ankle. The formation of fibrocartilage-like tissue, which is typically found in histological examination of tendinopathy, can be considered as an adaptation to this compressive load, driven by the tenocyte's mechanotransduction process. Therefore, it is recommended to reduce the amount of compressive load on the tendon during rehabilitation while exerting sufficient tensile load. However, these recommendations are mainly based on a pilot study and expert opinion. Therefore, this RCT investigates whether a therapy in which the amount of tendon compression is restricted during a progressive tendon-loading rehabilitation protocol actually has better outcomes in terms of pain scores, functionality and structure of the Achilles tendon in athletes with insertional Achilles tendinopathy. Limiting the amount of tendon compression on the Achilles tendon insertion will be achieved by (1) patient education, (2) heel inserts and (3) an adapted exercise regimen.

The principal investigator (LP) will be blinded to the assigned treatment throughout the data collection period. During the study, patients will be asked not to discuss their treatment exercises with the principal investigator but to consult an independent second sports physician (AB) if they have any questions about the therapy.

A progressive, criteria-based, 4-stage exercise protocol in which the amount of tendon compression is limited (12 weeks).

A progressive, criteria-based, 4-stage exercise protocol in which the amount of tendon compression is not limited (12 weeks).

The intervention treatment consists of a progressive 4-stage, criteria-based exercise protocol, in which the amount of tendon compression is limited. This includes: Education: Specific information on the importance of limiting tendon compression during rehabilitation, as well as general information on load management, the importance of active exercise therapy and setting expectations. Orthotic treatment: heel inserts to reduce ankle dorsiflexion during daily activities and sports Physiotherapy: Progressive tendon-loading exercise therapy (4 phases) restricting the amount of tendon compression by limiting dorsiflexion of the ankle and prohibiting stretching

The control treatment consists of a progressive 4-phase, criteria-based exercise protocol, in which the amount of tendon compression is not limited. This includes: Education: general information on load management, the importance of active exercise therapy and setting expectations. No orthotic treatment. Physiotherapy: Progressive tendon-loading exercise therapy (4 phases) without any restriction around tendon compression and encouraging stretching

The change of the Victorian Institute of Sports Assessment-Achilles Questionnaire (VISA-A) score over 12 weeks

The VISA-A score is a measure of pain and lower limb function (disability) associated with Achilles tendinopathy. A higher score indicates a better outcome and a 10 point increase is accepted as being clinically meaningful.

The change of the Victorian Institute of Sports Assessment-Achilles Questionnaire (VISA-A) score over 24 weeks

The VISA-A score is a measure of pain and lower limb function (disability) associated with Achilles tendinopathy. A higher score indicates a better outcome and a 10 point increase is accepted as being clinically meaningful.

Participation: return to desired sport on pre-injury level / return to desired sport but on a lower level / return to sports but not desired sport / no return to sports

This will be assessed at the start (week 0), at the end of the intervention (week 12) and at follow-up (week 24).

The lower extremity functional scale (LEFS) is a valid patient-rated outcome measure for the measurement of lower extremity function.

This will be assessed at the start (week 0), at the end of the intervention (week 12) and at follow-up (week 24).

The TSK is a 17-item self report checklist using a 4-point Likert scale that was developed as a measure of fear of movement or (re)injury.

This will be assessed at the start (week 0), at the end of the intervention (week 12) and at follow-up (week 24).

This will be assessed at the start (week 0), at the end of the intervention (week 12) and at follow-up (week 24).

This will be assessed at the start (week 0), at the end of the intervention (week 12) and at follow-up (week 24).

Self-reported pain (VAS, 0-100 mm) during activities of daily living over the last seven days. A higher score indicates more pain.

This will be assessed at the start (week 0), at the end of the intervention (week 12) and at follow-up (week 24).

This will be assessed at the start (week 0), at the end of the intervention (week 12) and at follow-up (week 24).

Compliance to the exercise programme and orthotics (total percentage of prescription) will be assessed using a short online questionnaire.

Numeric Pain Rating Scale (NRS, 0-10) during exercises, after exercises and in the morning will be assessed. A higher score indicates more pain.

As participants are not blinded about their assigned intervention, it is important to determine their beliefs about the treatment. With this in mind, participants will complete the Credibility/Expectations Questionnaire (CEQ) after being assigned to an intervention group.

Inclusion Criteria: Age 18-60 years old Diagnosed with insertional Achilles Tendinopathy by a sports medicine physician Have experienced symptoms for more than 3 months and less than 3 years Playing running-based sports at least twice a week Exclusion Criteria: Have a history of Achilles tendon rupture or surgery Have other disorders of the Achilles tendon or ankle (mid-portional Achilles tendinopathy, paratenonitis, osteoarthritis,...) Have rheumatological disorder (e.g. Spondylitis Ankylosis) Have metabolic or endocrine disorders, such as type I or type II diabetes Have had an Achilles injection in the past 3 months Have other conditions that prevent following an active exercise programme Have already been treated with physiotherapy, shockwave therapy or orthotics in the past 3 months Medication use with (fluoro)quinolones antibiotic in the past 2 years Currently pregnant