Achilles Tendon Injection | Achilles Tendinitis Treatment

Examination Findings

The essential element in the physical examination is the localization of swelling and tenderness in the Achilles tendon in the critical zone or at the insertion. Exquisite tenderness to palpation is a classic examination finding. Palpable heat is usually not evident unless peritendinitis is a major component. The Achilles is usually tight, with ankle dorsiflexion rarely extending beyond 90 degrees. Associated findings may include abnormal foot posture (pes planus or cavus), tight hamstrings, and muscle weakness of the entire hip and leg. Heels may not move into a normal varus position when standing on toes. Neurologic evaluation, including strength, sensation, and deep tendon reflexes, is normal.

The examination should also include observation for a palpable defect and the Thompson test (squeezing the calf, which should result in plantar flexion in an attached tendon) to rule out rupture of the Achilles tendon.

Imaging

X-rays are usually normal. Diagnostic ultrasonography or magnetic resonance imaging is capable of defining the extent of both tendinosis and peritendinitis.

Interventional Treatments For Achilles Tendinitis

Injection of local anaesthetic and steroids

Corticosteroid injections may have some early benefit but adverse effects were reported in up to 82% of corticosteroid trials; these include tendon rupture and decreased tendon strength is reported in animal studies. Any possible benefit of corticosteroid injection appears to be outweighed by potential risks, and hence steroid injections should be avoided.

Platelet rich plasma therapy (prp therapy)

Platelet-rich plasma (PRP) has become widely used in various areas of orthopaedics, with some studies demonstrating improved tendon healing using PRP compared with controls but significant improvement in symptoms has not been found when using PRP to treat Achilles tendinopathy. A randomised double-blind placebo-controlled study evaluating eccentric exercises and PRP or saline injection showed no difference in improvement in pain and activity at six months, and a recent meta-analysis concluded that although there may be benefit in using PRP to increase the healing strength in tendo Achilles repair following acute rupture, there was no evidence of any benefit in using PRP in the treatment of Achilles tendinopathy.

High volume injections

Small studies with limited follow-up have demonstrated reduced pain and improved function following high-volume injections of 10 ml 0.5% bupivacaine and 40 ml normal saline into the paratenon.

Technique

Achilles tendon injections are usually done on an outpatient basis. The procedure is performed under ultrasound guidance to ensure accuracy of needle placement. Patients need to be aware that the outcome of the procedure is variable and they may not receive the desired benefits. Similarly, they must be aware of the transient nature of the therapeutic benefits and that there may need repeated injections.

Either platelet rich plasma or high volume injections with local anaesthetic and saline are used. Steroids should be avoided because of risk of complications.

Complications

Complications are rare, particularly if the injections are performed using a precise needle-positioning technique. Possible complications include bruising, infection, hematoma, nerve injury and reaction to the injectates. Infection can be avoided with appropriate aseptic precautions. Severe allergic reactions to local anaesthetics are uncommon. Post-procedural pain flare-up may occasionally occur, and may be treated with pain killers. Neurological complications including paraesthesias and numbness have been described but are extremely rare.

Adverse effects have been reported with use of corticosteroids including tendon rupture and decreased tendon strength.

At Pain Spa Dr Krishna is very experienced in interventional treatments. Dr Krishna always performs Achilles tendon injections under ultrasound guidance for greater accuracy and improved safety. Ultrasound gives the added advantage of targeting the surrounding tendons and muscles, which can be contributory to pain.