Tendinopathy

Tendons connect muscle to bone, and transmit the force of contraction of the muscle thus moving the joint. They consist of 90% tenocytes and tenoblasts, and have a relatively poor blood supply which may account for delays in healing after injury. As an example the Achilles tendon has an area of poor blood supply between 2—7 cm above the Os Calcis (heel-bone); this is the area which most commonly ruptures in athletes. Tendons are elastic structures and can store energy during particular phases of running, jumping etc for later release, acting as springs — this has been extensively researched in racehorses, where degeneration and loss of this elasticity can be a ‘career’ ending injury.

Tendinopathy is not primarily an inflammatory process, but rather degenerative and may be caused by extrinsic factors, in particular repetitive shear forces across the tendon. Some medications have been associated with tendinopathy, including Ciprofloxacin (an antibiotic). Intrinsic factors include limb alignment problems, hyperpronation, muscle tightness and imbalance. A body mass index of >30 is associated with increased risk of tendinopathy, and more rarely systemic disorders such as Rheumatoid arthritis.

Tendinopathy typically causes tenderness, swelling and pain on activity of the affected tendon. Ultrasound scanning is very useful in delineating the area and severity of damage, MRI may be useful to exclude other intra-articular problems.

Treatment

Relative rest, avoiding only exacerbating factors.

Physiotherapy is important to correct underlying muscle/postural imbalance, with stretching exercises and local massage, interferential & ultrasound to try and stimulate healing. Eccentric muscle strengthening exercise has been shown to be particularly beneficial in stimulating healing and remodelling of the tendon – these exercises will initially be painful, and may take several months to show benefit.

Cortisone injection has been frequently used but shows no long term improvement over other treatments, and there are risks of tendon rupture; they should not be used around the Achilles tendon.

Recent research is focussed on stimulating healing of damaged tendon by injection of autologous (the patient’s own) blood; we have shown good results in 17/20 cases of resistant tennis elbow who would otherwise been offered surgical repair.

You may have heard of some premier league soccer players having calves blood injected into their patella tendons to stimulate healing, although why they have used calves blood rather than the patient’s own escapes me! It is believed that there are many growth factors attached to the platelets in the blood which attract stem cells and stimulate formation of new tendon cells.

An exciting new avenue of research is in cell culture techniques for growing tenocytes from skin biopsy (a tiny piece of skin harvested under local anaesthesia) for later reimplantation; we have completed a pilot study for tennis elbow and have expanded this for the rotator cuff, patella and Achilles tendons.

Surgical treatment is reserved for recalcitrant cases and aims to excise the damaged areas of tendon with repair back onto the bone; it may require use of soft tissue anchors to reattach the tendon and ‘pull’ it directly to the bone. Although the success rates of surgical treatment are good (75 — 90% success) the rehabilitation may be prolonged with ongoing physical therapy, and so it is definitely not a ‘short-cut’

References:

Ultrasound-guided autologous blood injection for tennis elbow.
David A Connell, Kaline E Ali, Muaaze Ahmed, Simon Lambert, Steven Corbett,
Mark J Curtis.
Skeletal Radiol 2006;35 (6):371-377