Introduction Tendinopathy is a common musculoskeletal condition that is prevalent in both the sporting and sedentary population, and Achilles tendinopathy (AT) has a higher prevalence than any other tendinopathy site (de Jonge, 2011). The annual incidence of Achilles tendinopathy has been estimated at 9% in top level runners (Lysholm, 1987) and elite long distance runners have a lifetime risk of 52% (Kujala, 2005). Clinically, tendinopathy presents with tendon pain with loading, tenderness on palpation and impaired function (Kountoris, 2007). Topical glyceryl trinitrate (GTN) has exhibited a role in tendon healing via increasing nitric oxide, which in turn causes fibroblast proliferation, collagen synthesis, contraction of collagen lattices and local vasodilation (Paoloni, 2004; Murrell, 1997). The majority of research in the area of GTN and AT has been conducted by one group (Paoloni, 2004) but there is conflict in the literature, as the results have not been replicated (Kane, 2008).

Methods A 32-year old male triathlete presented with a seven year history of Achilles tendinopathy which had failed conservative treatment. Tendinopathic changes were confirmed on MRI. The patient reported intermittent Achilles pain related to running and was unable to train or participate in running components of triathlons due to the Achilles pain. Swimming and cycling were pain-free. The patient had declined injection therapies and surgery. Local pain and stiffness were particularly noticed in the morning. Any attempts at running caused alteration of running technique, reduction in performance times and pain for three days thereafter.

Initial presentation (Day 1) Initial examination revealed tenderness and palpable thickening in the mid-portion of the right Achilles. The following outcome measures were administered: Victoria Institute of Sports Assessment (VISA-A), Lower Extremity Functional Scale (LEFS) and Numerical Rating Scale (NRS) (Table 1). Repeat assessments were conducted at days 30, 60, 90 and 180.

Treatment The option of using topical GTN patches as an adjunct to the exercise regime was discussed and the possible side effects were highlighted. The patient consented to this treatment. The GTN patch was prescribed by a consultant rheumatologist, and administered as outlined by Paoloni et al (2004), one quarter patch delivering 1.25 mg/day placed on the affected tendon and replaced daily, for 6 months. The patient also commenced a phased Achilles tendon loading programme (Silbernagel, 2007).

Results The patient had made a complete recovery and was asymptomatic by day 180 (see table 1) and the affected Achilles was no longer tender on palpation. The patient had returned to running and triathlete training, running 7 km at a pace of 3 min 41 seconds per kilometre.

Discussion The evidence to date suggests that GTN has a potential role in the treatment of tendinopathy as an adjunct to exercise. This case highlights the benefit of topical GTN as an adjunct to a specific exercise programme and as a treatment consideration for a triathlete with recalcitrant Achilles tendinopathy. Further trials would be useful in validating the role of GTN as a potential modality in the treatment of tendinopathy.

References de Jonge, et al . BJSM. 2011;45 (13): 1026–28

Kountouris, et al. Best Practice & Res Clin Rheum. 2007;21 (2): 295–316

Kujala, et al . Clin J of Sp Med. 2005;15 (3): 133–35

Lysholm, et al . AJSM. 1987;15 (2): 168–71

Paoloni, et al . JBJS. 2004;86 (5): 916–22

Silbernagel, et al . AJSM. 2007;35 (6): 897–906