VANCOUVER, BC – Patients with chronic tendinosis of the Achilles or infrapatellar tendons may find relief from ultrasound-guided injections of hyperosmolar dextrose into the offending tendon, according to Anthony Wong, MD, of St. Paul's Hospital, Vancouver, BC. Dr. Wong reported results from a 30-patient series at the American Roentgen Ray Society 2006 Annual Meeting.¹

"Twenty-four of the 30 patients were very satisfied with the outcome of their treatment. Three patients did not respond to the treatment and opted for surgery. Three more patients had incomplete treatment and did not keep their follow-up appointments," Dr. Wong said.

The 30 patients (22 men and 8 women, mean age 50 years) had chronic tendinosis. "All of the patients had long-term injuries of up to 10 years' duration, and all had failed conservative management by sports medicine physicians. This was their last option before surgery," Dr. Wong told CIAOMed.

Patients received a mean of 4.0 injections per tendon (range 2–11). "I treat the painful sites of the tendon and may [administer] up to five injections," Dr. Wong said. "The volume of injection varies from patient to patient, from 1–3 CCs. Initially the injections are painful, but as the tendon heals they become almost painless," Dr. Wong said, adding that he mixes local analgesia into the solution. He noted that hyperosmolar dextrose has been used to sclerose tendon and ligament insertions, but that those injections are not done under sonographic guidance or into the body of the tendon.

The hyperosmolar dextrose injections significantly reduced tendon pain in 43 of 53 tendons. Achilles tendon treatment reduced VAS scores for pain at rest by 87.1%, for pain during normal activity by 84.7%, and for tendon pain after sporting or other physical activity by 82.2%. Similar improvements were observed in infrapatellar pain.

Dr. Wong said that patients who did not respond to treatment had cortical irregularity and calcifications at the tendon insert.

Treatment also reduced the characteristic pathologic changes associated with chronic tendinosis. Dr. Wong explained that all study subjects had thickened and demonstrated changes consistent with chronic tendinosis prior to treatment but had only "minimal" sonographic changes after treatment.

"We think that the mechanism of action is that the dextrose injection causes an inflammatory response in the tendon, resulting in the deposition of collagen, which helps repair the damage in the tendon structure that occurs in chronic tendinosis. Incidentally, the disruption of the tendon structure can often be seen during the dextrose injection and depends on the severity of the injury," Dr. Wong said.

He explained that the procedure requires some expertise in directing a needle under ultrasound guidance into relatively small structures. He also noted that the treatment effect appears to be quite durable. "I have been doing the procedure for about 3 years and have not had any relapses to date," he said.

Reference

1. Maxwell NJ, Ryan M, Taunton JE, Wong A. Ultrasound-guided intratendinous injection of hyperosmolar dextrose in the treatment of chronic tendinosis of the infrapatellar and Achilles tendons. Presented at: American Roentgen Ray Society 106th Annual Meeting; April 30–May 5; Vancouver, BC. Abstract 172.