NEW YORK (Reuters Health) — In the treatment of chronic pain and tenderness around the knee cap, or "patella," shockwave therapy seems to be safer and more effective, with lower recurrence rates, than conventional conservative treatments, suggest the results of a new study.Conservative treatments are recommended for this chronic overuse syndrome, also referred to as patellar tendinopathy, lead author Dr. Ching-Jen Wang told Reuters Health. "However, the recurrent symptoms are high."

Conservative treatment typically includes analgesics, such as ibuprofen or naproxen, along with physical and exercise therapy.

However, based on the current study, "one would consider shockwave as the treatment of choice in athletes with recurrent patellar tendinopathy," Wang said.

Chronic patellar tendinopathy is an overuse syndrome with pathologic changes and tendon injury, similar to tendinopathy of the shoulder, elbow, and heel, Wang, from Chang Gung University College of Medicine, Kaohsiung, Taiwan and colleagues explain in the American Journal of Sports Medicine.

Non-invasive extracorporeal (outside the body) shockwave therapy has shown to be effective for many tendinopathies.

In a group of individuals with chronic patellar tendinopathy, Wang's team compared the efficacy of 1500 impulses of extracorporeal shockwave at 14 KV to the affected knee in a single session with that of conservative management consisting of nonsteroidal anti-inflammatory drugs, physiotherapy, exercise, and a knee strap.

They randomly assigned 27 patients (30 knees) to shockwave therapy and 23 patients (24 knees) to the conservative management group (controls).

After two to three years of follow-up, overall results were significantly better in the shockwave group than in the conservative management group.

In the shockwave group, outcomes were deemed "excellent" in 43 percent of patients, "good" in 47 percent, "fair" in ten percent and "poor" in none.

In the conservative group, none had excellent outcomes, and outcomes were good in 50 percent, fair in 25 percent and poor in 25 percent.

Pain scores and range of knee motion, which were similar in the two groups before treatment, improved significantly after treatment in the shockwave group but not in the control group.

Recurrent symptoms were noted in 13 percent of the shockwave group (four of 30) versus 50 percent of the control group (12 of 24).

Ultrasound revealed a significant increase in the blood flow around the patellar tendon after shockwave therapy compared with conservative therapy, the authors note.

However, there were no significant between-group differences in the appearance, arrangement, and composition of tendon fibres. There were no complications of shockwave therapy.