depth of a few millimetres, although it is possible to stimulate tissues at a depth of up to 15mm below the skin. Beneficial effects on tissue healing are proposed to occur through stimulation of cellular and chemical aspects of the healing process, in particular in the early phases. Pain reduction may also take place through reduction of muscle spasm or alteration of nerve conduction velocity. Nevertheless, the clinical utility of laser therapy remains unestablished.

The non-thermal effects of

ultrasound may be more important than the thermal effects in the treatment of soft tissue lesions. These non- thermal properties of ultrasound include cavitation and acoustic microstreaming. Effects of cavitation and microstreaming that have been demonstrated in vitro include stimulation of fibroblast repair and collagen synthesis, tissue regeneration and bone healing. Adverse effects of ultrasound, such as tissue damage with excessive doses, have also been reported. Ultrasound interacts with one or

more components of inflammation, and earlier resolution of inflammation, accelerated fibrinolysis, stimulation of macrophage-derived fibroblast mitogenic factors, heightened fibroblast recruitment, accelerated angiogenesis, increased matrix synthesis, more dense collagen fibrils and increased tissue tensile strength have all been demonstrated in vitro. Such findings form the basis of the rationale for the use of ultrasound to promote and accelerate tissue healing and repair. However, research on the use of ultrasound specifically in tendon healing is minimal and relates only to animals; the evidence for clinical benefit in humans is limited (5). Low-intensity pulsed ultrasound

(LIPUS) may be of use in the healing of bone tendon interface lesions (eg. in a bone-patellar-bone graft). More research in relation to enthesopathies is needed.

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Pulsed shockwave therapy is used in the management of painful chronic tendinopathies. This may be to dissipate calcification, particularly in the true calcific tendinopathy, or to relieve pain through denervation such as in the patellar tendinosis. Stimulation of tendon healing has been demonstrated in fracture non-unions and in tendons in animal models, but it has not been studied in humans.

The use of a laser to cut and

destroy tissue is well established. The same electromagnetic radiation, at much lower intensities, can elicit non-destructive physiological responses in tissues in the absence of significant heating (‘cold laser therapy’). This phenomenon forms the basis for the use of laser therapy in the management of a variety of soft tissue complaints, including tendon injuries. The proposed effects of laser therapy are analgesia and tissue healing, with the latter resembling the non-thermal effects proposed for therapeutic ultrasound. Laser energy commonly penetrates tissues at a

USUALLY NOT NECCESSARY WITH ADEQUATE CONSERVATIVE MANAGEMENT

SURGERY OFTEN ADVOCATED BUT IS

Injection therapies Injection therapies are frequently used for tendinopathies but should not detract from the focus of sound rehabilitation. Historically, corticosteroid injections (peritendinous or intrasheath) have been used. Particularly in athletes, these should be used with caution and avoided in tendons that are heavily loaded, such as the Achilles. Potential adverse effects include tendon degradation, flares of pain, sepsis (rare), menstrual disturbances and compromised effectiveness. Corticosteroid injections should be used sparingly and should be guided by imaging, usually ultrasound. Local anaesthetic injections can be helpful in confirming the source of pain in a chronic tendon/soft tissue complaint. They are also useful in patients with chronic Achilles paratenon adhesions.

Sclerosant therapy, targeting

the new vessels within the diseased tendon, has also been advocated, on the basis that eradication of the vessels significantly reduces pain (6). Autologous blood injections have gained some attention over recent years and are used with the rationale that they provide normal healthy growth factors to the injured tendon. Initially used effectively in racehorses, they have gained popularity in human tendon injuries with some clinicians, but the equine world has moved on to stem cell therapy.

Equipment modification Modification of equipment and technique may be necessary. In some athletes with lower limb biomechanical issues, orthotics are helpful. Orthotics should be fitted only by an experienced podiatrist or physiotherapist after objective biomechanical gait analysis. Strapping and supports are also

sportEX medicine 2009;39(Jan):7-11