Sir,
We read with great interest the recent work by Levy et al. In this
paper, the authors aimed at defining the microcirculation of the normal
rotator cuff during arthroscopic surgery and investigating whether it is
altered in diseased cuff tissue. We would appreciate commenting on some
aspects.
The authors demonstrated significant differences between the mean flux in
normal and diseased cuffs. Blood flow
was lower in those with impingement than in normal cuffs.
This observation is in contrast to a broad number of reports in
tendinopathy.
Alfredson et al recently found similar histological changes in the
supraspinatus tendon compared with findings in Achilles-, patellar- and
extensor carpi radialis brevis (ECRB)-tendinopathy.1 They reported a
vasculo-neural ingrowth in tendinopathy and demonstrated good short-term
clinical effects with injections of the sclerosing substance polidocanol
in painful chronic shoulder impingement. At follow-up, eight (median) (range 4 to 17) months after the treatment, 14 patients were satisfied with the
result. Using the visual analogue scale evaluation (VAS), the pain dropped
from 79 before treatment to 21 at follow-up (P < 0.05).
The authors cited a study by Swiontkowski et al from the 1990s who
performed laser Doppler flowmetry studies on patients during open surgery
for rotator cuff disease.2 They could demonstrate hyperaemia in
supraspinatus impingement.
These findings from the 1990s were as controversial to the study of
Levy et al as current studies by Alfredson and Knobloch.3 These
studies in Achilles tendinopathy demonstrated a significantly higher blood
flow in tendinopathic tendons than in healthy tendons assessed by laser Doppler flowmetry at the point of pain.
Post-capillary venous filling pressure as a marker of venous stasis
was also elevated in tendinopathic Achilles tendons. As far as treatment
response in tendinopathy is concerned, we were able to show a significant
decrease of both tendinous blood flow and post-capillary venous filling
pressure by a 12-week eccentric training intervention.
In supraspinatus tendinopathy, a double-blind, placebo-controlled
randomised trial demonstrated that topical glyceryl trinitrate treatment
significantly improved pain scores, range of motion, internal rotation
impingement, muscular force, and patient outcomes in patients with
supraspinatus tendinopathy.4 Topical glyceryl trinitrate should be
considered as part of nonsurgical management of chronic tendinopathies.
In summary, there is evolving evidence that hypervascularity, namely
neovascularisation, does play a role in tendinopathy. Treatment options
focusing on the modification of hypervascularisation have already
demonstrated encouraging clinical results. However, future randomised controlled trials at best are pending in supraspinatus tendinopathy.
R. Kraemer,
Plastic, Hand and Reconstructive Surgery,
K. Knobloch,
Hannover Medical School,
Hannover, Germany.
1. Alfredson H, Harstad H, Haugen S, Ohberg L. Sclerosing polidocanol
injections to treat chronic painful shoulder impingement syndrome: results
of a two-centre collaborative pilot study. Knee Surg Sports Traumatol Arthrosc 2006;14:1321-6.
2. Swiontkowski MF, Iannotti JP, Boulas HJ, Esterhai JL. Intraoperative
assessment of rotator cuff vascularity using laser Doppler flowmetry.
In: Post M, Morr, eds. Surgery of the shoulder. St Louis: Mosby, 1990:208-12.
3. Knobloch K, Kraemer R, Lichtenberg A, et al. Achilles tendon and paratendon microcirculation in midportion
and insertional tendinopathy in athletes. Am J Sports Med 2006;34:92-7.
4. Paoloni JA, Appleyard RC, Nelson J, Murrell GA. Topical glyceryl
trinitrate application in the treatment of chronic supraspinatus
tendinopathy: a randomized, double-blinded, placebo-controlled clinical
trial. Am J Sports Med 2005;33:806-13.
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