Sonographically guided patellar tendon fenestration: prognostic value of preprocedure sonographic findings

The purpose of this study was to determine whether any sonographic features of jumper's knee can predict the outcome after sonographically guided percutaneous patellar tendon fenestration.

Patients were identified between July 2001 and March 2009 who had clinical and sonographic findings of jumper's knee, who had failed conservative treatment, and who had sonographically guided percutaneous fenestration of the patellar tendon. Pain levels were assessed before and 4 weeks after fenestration. Sonograms were retrospectively characterized with regard to echogenicity, size, definition, location, calcification, and hyperemia of the abnormal patellar tendon region. Sonographic findings before fenestration were correlated with clinical outcomes.

A total of 45 patellar tendons (32 consecutive patients) were included in the study. The average prefenestration functional pain score was 3.6 (range, 2-5), and the average postprocedure functional pain score after 4 weeks was 1.4 (range, 0-5). The preprocedure sonographic finding that correlated with an improved clinical outcome after tendon fenestration was the presence of a well-defined tendon abnormality. No other sonographic findings were associated with the clinical outcome. After fenestration, 76% (34 of 45) showed clinical improvement; 24% (11 of 45) showed no change; and 0% (0 of 45) had worse symptoms at 4 weeks.

The presence of a well-defined area of tendinosis on sonography was associated with clinical improvement after percutaneous sonographically guided fenestration of the patellar tendon. All tendons either improved (76%) or showed no change (24%) in the functional pain score at 4 weeks after fenestration.