High volume ultrasound guided injections at the interface between the patellar tendon and Hoffa's body are effective in chronic patellar tendinopathy: A pilot study

PURPOSE: To evaluate a novel conservative management modality for patellar tendinopathy. METHODS: We recruited nine patients with patellar tendinopathy who had failed conservative management and showed evidence of neovascularisation on power Doppler scanning. A high volume ultrasound guided injection at the interface between the patellar tendon and Hoffa's body. The injection contained 10 ml 0.5% Bupivacaine, 25 mg Hydrocortisone, and between 12 and 40 ml normosaline. 100 mm visual analogue scales (VAS) for pain and for function, and Victorian Institute of Sport Assessment - Patellar tendon (VISA-P) questionnaires at an average of 9 months from the injection. RESULTS: All but one patient (whose pain was unchanged) improved (p = 0.028). The mean improvement in function 2 weeks after injection was 58 mm on VAS (interquartile range 27 - 88, p = 0.018). The mean improvement in pain 2 weeks after injection was 56 mm on a VAS scale (interquartile range 32 - 80, p = 0.018). At a mean follow up of 9 months, an improvement of 22 points from a baseline score of 46 on the VISA-P questionnaire (100 being normal) was established. CONCLUSION: High volume injections to mechanically disrupt the neovascularisation in patellar tendinopathy are helpful in the management of this condition. Controlled trials would be warranted to investigate in a more conclusive fashion this management modality.