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

Abstract

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.

Keywords:

• Patellar
• tendinopathy
• ultrasound guided injections
• collagen
• matrix
• neovascularisation
• jumper's knee