This is the first study evaluating the 5-years results of the Alfredson heel-drop programme with the validated VISA-A score. The VISA-A score increased significantly from 49.2 at baseline to 83.6 at the 5-year follow-up and from the 1-year follow-up to 5-year follow-up from 75.0 to 83.4 (p<0.01).
Until now the VISA-A score has only been used in one long-term follow-up study on eccentric exercises in Achilles tendinopathy.16
Silbernagel et al
reported a VISA-A score of 90.5 at 5-year follow-up, 65% of symptom-free patients and approximately 6% receiving alternative treatments. In their study, the training programme lasted from 12 weeks to 6 months and was performed under the supervision of a physiotherapist. Patients in the current study received very accurate instruction for the heel-drop programme and were instructed to do the exercises with pain. The compliance for the exercises was good/excellent in the majority of the patients (>70%).13
The basic population of Silbernagel et al
showed many similarities with our population, however, no competitive athletes were included in the study of Silbernagel et al
. Maffulli et al20
suggested there could be a difference in response to eccentric training in the Scandinavian population. Several Scandinavian studies have demonstrated good/excellent short-term results from the eccentric exercises in the treatment of chronic Achilles tendinopathy.9–12
In recent years, differing results have been found by non-Scandinavian studies showing only moderate short-term results.13
The long-term Scandinavian studies evaluating eccentric exercises in chronic Achilles tendinopathy suggest a good long-term prognosis.14–16
Further studies will be needed to reveal if there is a genetic explanation for this difference.23
Two other studies have reported long-term effects of the heel-drop programme used in this study in patients with Achilles tendinopathy.14
However, neither of them used the validated VISA-A score. Ohberg et al
showed that 22 of 25 (88%) patients were satisfied with the treatment at a mean follow-up of 3.8 years (range 1.6–7.75). The second long-term follow-up study reported that 65% of the patients had no or mild pain after 4.2 years (range 29–58 months).14
In our study, 39.7% of the study population was completely pain-free at the 5-year follow-up. Almost half of our patients had received one or more alternative treatments. These secondary subjective outcomes suggest a discrepancy with the significant increase of the primary outcome score. For advise to patients it implies that a quantified improvement can be expected, but mild remaining pain symptoms may be present at long term.
Ultrasonographic evaluation demonstrated a comparable decrease in tendon thickness from 8.8 mm before the heel-drop programme to 7.6 mm at follow-up. However, the clinical relevance of this minor decrease is questionable. In recent years, a debate has arisen about the meaning and the significance of neovascularisation in Achilles tendons. Some studies have found a correlation between the patient's symptoms and the degree of neovascularisation,24–26
and others found that the presence of neovascularisation did not per se indicate a disease state.27–31
Also the circumstances during the examination, for example, activity just before the measurement, was not controlled and is unknown. This study found that the VISA-A score was not related to the degree of neovascularisation. Further research is needed to understand the relevance of neovascularisation in Achilles tendons.
This study has some limitations. The 11 dropouts might have influenced the outcome. In a best case scenario analysis where the dropouts have the best outcome score, 50% of the patients would be pain-free. However, the value of this non-validated subjective outcome measurement is questionable. Patients had to answer questions concerning the last 5 years, which may have given recall bias. The long-term outcome could be influenced by the alternative treatments that the patients received after completion of the heel-drop programme. However, of the patients who did not receive alternative treatments, 56.7% were completely pain-free after 5 years. Robinson et al17
recommended to use the VISA-A score in a homogenous group of athletes. Especially at long-term follow-up, the VISA-A score questionnaire can be subject to other influences than solely the symptoms of the Achilles tendinopathy. Factors like general ageing and new comorbidity may have influenced the outcome in this study. Finally, the ultrasonographic examinations at baseline and at follow-up were performed by different observers. However, in an earlier study, an excellent interobserver reliability of grading the neovascularisation was found.32
What this study adds
Patients with chronic Achilles tendinopathy treated with Alfredson's heel-drop exercise programme continue to improve, as measured by the VISA-A score, up to 5 years after completion of the programme.