Page 137 - JSOM Spring 2020

about their use of orthotics found that 73% of AT patients re- body, thus providing localized NO secretions. NO is a free
87
ported total or “great” improvement of symptoms with the or- radical produced when nitric oxide synthases (NOS) catalyzes
thotics. A randomized controlled trial showed a reduction in the conversion of l-arginine to l-citrulline. NO is toxic at high
78
pain in runners wearing orthotics after 4 weeks compared to dosages, but at lower dosages it appears to be involved in ten-
a control group without orthotics. However, these findings don healing, in addition to effecting vasodilation, memory, and
79
may have been due to a placebo effect since both patients and immune function. In rat models of uninjured Achilles tendons
researchers knew which group wore orthotics. A more recent there was little or no NOS activity, but after injury a 5-fold in-
study had participants use either a custom foot orthotic or a crease in the conversion of l-arginine to l-citrulline was found
80
sham orthotic that provided virtually no support. Participants suggesting increased NOS activity. In injured human tendons,
in both groups also followed the 12-week Alfredson eccentric NOS expression was upregulated and isolated human teno-
exercise protocol. In follow-ups at 1, 3, 6, and 12 months, cytes exposure to NO increased collagen synthesis. 88
there were no significant group differences on VISA-A scores
(pain and function), participant perception of treatment effec- Table 2 presents a summary of data from studies that have
tiveness, or level of physical activity between the two groups. evaluated the effectiveness of glyceryl trinitrate patches for
Thus, the current data suggest that orthotics are not effective reducing pain and improving function in patients with AT.
in reducing pain and improving function in AT. 68 One study was a long-term follow-up of an earlier study
89
90
and is thus included in the row with the earlier study. Data
90
Bracing from most studies 88–90 indicated that when glyceryl trinitrate
Bracing or splinting has been advocated for the treatment of patches were provided to patients, pain, tenderness, and dis-
AT. This involves applying and wearing a brace around the ability were reduced compared to patients who did not receive
ankle and over the Achilles tendon so that the ankle joint is the patches. However, one study found no difference in pain
91
resting in a supported neutral or dorsiflexed position. An ex- or disability scores after 6 months of treatment between those
ample of a brace is shown in Figure 7. At least five studies 81–85 wearing the patch and those wearing a placebo patch when
have compared the effects of eccentric exercise alone with eccentric exercise was provided to both groups. Interestingly,
eccentric exercise plus the use of a brace in the treatment of three patients in the placebo group and four in the glyceryl
AT. In one study, the sample sizes were small (n = 6 and 5 trinitrate patch group went on to have surgery and histological
84
per group) and no statistical analysis was reported. The other examination of Achilles tendon tissue showed no group differ-
studies found no significant group differences on pain symp- ences in neovascularization, collagen synthesis, or expression
toms, 81–83,85 patient subjective functional evaluations, 81–83 , or of NOS activity. In summary, further studies are required be-
patient satisfaction, although both patient groups generally fore the effectiveness of glyceryl trinitrate patches for AT can
83
improved over the treatment periods (3 to 12 months). In three be determined. Nonetheless, these patches may provide some
studies, patients wore the braces at night 83–85 and in two stud- relief and a more rapid return to greater function for some
ies, 81,82 during the day. One study found that tendon micro- patients. The major adverse effects appear to be headaches and
81
circulation was improved to a greater extent with a brace that skin rashes, 90,91 although in one study the proportion report-
90
had air cells over the Achilles tendon and that applied massage ing these effects was about the same in placebo and glyceryl
on the Achilles tendon while walking; this was despite the lack trinitrate patch groups.
of group differences in pain or function. Another study found
no change in tendon diameter in the treatment groups with Injection Therapies
follow-ups to 12 months. In summary, the use of braces does There are many injection therapies for AT treatment, all of
82
not appear to offer any advantage in terms of pain, function, which involve direct injections of substances into or near the
or patient satisfaction over eccentric exercise alone. 68 Achilles tendon. The mechanism of action is assumed to be
either pharmacological (direct action of injected substances
on tissue leading to healing) or mechanical (disruption of
pain processes). These therapies can be delivered using ultra-
sound guided techniques or delivered into the tissue without
guidance.
FIGURE 7 Example of a
bracing device for treating Corticosteroid Injections. Corticosteroids control inflamma-
Achilles tendinopathy (from tion by increasing the transcription of anti-inflammatory genes
https://www.djoglobal.com/ 92
products/aircast/airheel- and decreasing the transcription of inflammatory genes.
stabilizers). However, the use of these substances is controversial since,
as discussed above, inflammation in AT may be minimal
28
and anti-inflammatory treatments may detrimentally affect
normal tendon healing processes. Nonetheless, studies gen-
66
erally show that injection of glucocorticoids provide immedi-
ate short-term reduction in pain, reduce tendon thickness, and
increase function 93–96 ; however, many of these improvements
Glyceryl Trinitrate Patches are less well maintained in the longer term, 93,96 even when
Experiments have been conducted on the effectiveness of combined with postinjection eccentric exercise. Some stud-
97
transdermal patches containing glyceryl trinitrate in the treat- ies 94,97,98 have used ultrasonography to guide high-volume in-
ment of various tendinopathies, including AT. The patch is jections (50 to 90mL) of corticosteroids and other substances
86
placed directly over the Achilles tendon at the point of max- into the Achilles tendon of patients with chronic AT. The ratio-
imal pain. Glyceryl trinitrate is a biologically inactive com- nale is that the volume of these injections will disrupt the neo-
pound enzymatically converted to nitric oxide (NO) in the vascularization (thus reducing the ingrowth of the new nerve

Achilles Tendinopathy | 131