Background: Therapeutic ultrasound is one of several rehabilitation interventions suggested for the management of pain due to patellofemoral pain syndrome.

Objectives: To assess the effectiveness and side effects of ultrasound therapy for treating patellofemoral pain syndrome.

Search strategy: We searched MEDLINE, Embase, Healthstar, Sports Discus, CINAHL, the Cochrane Controlled Trials Register, the PEDro database, the specialized registry of the Cochrane musculoskeletal group and the Cochrane field of physical and related therapies up to December 2000 according to the sensitive search strategy for RCTs designed for the Cochrane Collaboration. The search was complemented with handsearching of the reference lists. Key experts in the area were contacted for further articles.

Selection criteria: All randomized controlled trials (RCTs) and controlled clinical trials (CCTs), case-control and cohort studies comparing therapeutic ultrasound against placebo or another active intervention in patients with patellofemoral pain syndrome were selected, according to an a priori protocol.

Data collection and analysis: Two reviewers determined the studies to be included based on a priori inclusion criteria (LB, VAR). Data were independently abstracted by the same two reviewers, and checked by a third reviewer (BS) using a pre-developed form. The same two reviewers, using a validated scale, independently assessed the methodological quality of the RCTs and CCTs. The data analysis was performed using Peto Odds ratios.

Main results: The search retrieved 85 articles. Of the 8 that were potentially relevant, only one RCT, including 53 patients with patellofemoral pain syndrome, was included. All patients received exercises as a concurrent therapy. Ultrasound combined with ice massage contrast (n=13) was not statistically different from ice massage alone (n=16) in terms of patient-rated pain relief improvement, quadriceps and hamstring strength. In the ultrasound and ice massage group, 46% (6/13) reported improved pain relief compared to 31% (4/13) in the ice massage alone group. This difference of 15% does not meet international standards for clinically important improvement in osteoarthritis of 20%. Side effects were not reported.

Reviewer's conclusions: Ultrasound therapy was not shown to have a clinically important effect on pain relief for patients with patellofemoral pain syndrome. These conclusions are limited by the poor reporting of the therapeutic application of the ultrasound and low methodological quality of the trial included. No conclusions can be drawn concerning the use or non use of ultrasound for treating patellofemoral pain syndrome. More well-designed studies are needed.