IN VITRO EFFECTS OF PRP INJECTIONS SUPPLEMENTED WITH STEROIDS AND/OR ANESTHETICS ON TENDON

Authors: A Mazzocca; D Chowaniec; R Arciero; MB Mccarthy

References: Presented at SECEC 2009

Purpose
Tendinopathy has been recently treated nonsurgically with the injection of conditioned plasma or PRP. Injections are commonly supplemented with steroids and/or anesthetics to decrease inflammation and pain. The purpose of this study was to see how tendon responds to these injections in vitro.

Material and Methods
Peripheral blood (PB) was collected from patients (n = 6). Conditioned plasma (5min centrifugation) and PRP fractions (2 centrifugations 5 and 20min) were obtained from PB. Human tenocytes were obtained from the biceps tendon, characterized by phenotypic and molecular analysis. Proliferation was determined by measuring [3H] -Thymidine uptake in cells treated with conditioned plasma and PRP supplemented with 40 mg/mL Depo-Medrol and/or 1% Lidocaine or 0.25% Marcaine. Control groups were: 2% fetal bovine serum (FBS) which is the minimal required amount to maintain cells & 10% FBS for normal cell growth.

Results
Conditioned plasma and PRP injections significantly increased tenocyte proliferation over the 2% and 10% FBS control group (18.4 & 16.5, 0.97 & 3.8 x104 DPM). Conditioned plasma and PRP supplemented with 40 mg/mL Depo-Medrol less appreciably increased tenocyte proliferation over the 2% and 10% FBS controls (4.5 & 5.2, 0.97 & 3.8 x104 DPM). Groups treated with conditioned plasma or PRP with either 1% lidocaine or 0.25% marcaine resulted in tenocyte death.

Conclusion
Although injections of conditioned plasma and PRP alone seem to stimulate tenocyte proliferation, the additional injection of cortisone and/or anesthetics results in tenocyte death. Clinically, supplementing PRP injections with anesthetics or steroids may have a negative effect on tendon healing.