VASCULARITY AND TENDON PAIN ture was shown to have normalised (16).

The effectiveness of the treatment was demonstrated in a prospec- tive randomised double-blind study where the effect of the scleros- ing substance was compared to a short-term vasoconstrictant. This study showed no effect from the non-sclerosing substance com- pared to an 80% good effect with the sclerosing substance (17).

Overall sclerosing therapy has been used in more than 500 tendons with very few complications, suggesting that the theory that excess vascularity is not necessary for tendon repair, is correct. The treat- ment appears to be less successful in those with bony changes at the Achilles insertion and in jumping athletes with patellar tendinopathy.

It is not known the exact effect that sclerosing has. Originally it was thought that the effects were directly on the vessels, but recent investigations have shown that the vessels persist after injection for several months. Close follow ups with US imaging in both the Achilles and patellar tendons showed that although the flow was markedly decreased immediately after the sclerosing treat- ment, it returned by three days and remained high until more than two months after the injection.

As tendon pain is reduced by the sclerosing treatment and vascu- larity is not affected, the effect of the treatment may be on the nerve, as the sclerosing substance used is also mildly neurotoxic. The vessels may be just a marker of neural ingrowth and direct treatment to the right spot (18). Further research to clarify what underpins the positive effects of the sclerosing injections are needed.

Other treatments Indirect treatments that have been known to be effective clinical- ly to reduce pain in tendons, such as night splints for the Achilles and infrapatellar braces for the patellar tendon, may in fact affect or alter vascularity and/or nerve conduction. These can be used to reduce pain while the tendon is rehabilitated.

In summary, tendon vascularity is a corner stone of tendon pathol- ogy. It is associated with nerves but its direct association with pain has not yet been demonstrated. Direct treatment to decrease vas- cularity has been shown to be beneficial, however vascularity is not associated with outcome if not directly treated. More research is needed to answer these questions.

THE AUTHOR

Dr Jill Cook is associate professor and reader in the school of physio- therapy at La Trobe University, Melbourne, Australia where she is also holds an NHMRC Australian Health Professional Research Fellowship (2003-2007) to investigate tendon vascularity. Jill graduated as a physiotherapist in 1977 and completed her post-graduate diploma of Manipulative Therapy in 1991, and then her PhD in 2000, where she investigated clinical and imaging aspects of patellar tendinopathy in athletes. She joined the Musculoskeletal Research Centre at La Trobe University in 2000 and currently supplements her research by coordi- nating the post graduate sports physiotherapy courses at La Trobe University, conducting a specialist tendon practice and by lecturing and presenting workshops both in Australia and overseas.

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Jill is currently chair of the Sports Medicine Australia Conference organising committee and was appointed a fellowship to Sports Medicine Australia in 2005.

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