PRP vs PRP Plus IGF for Patellar Tendinosis

Introduction/Background:

Patellar tendinosis is a frustrating ailment commonly encountered in sports medicine. Treating this condition continues to be a significant challenge for sports medicine physicians. The tendinosis lesion is characterized by collagen disorganization and increased ground substance. One method of treating this problem is using platelet rich plasma (PRP), which is a concentration of platelets from the patient's own blood that provides a high dose of growth factors aimed at stimulating tendon healing. These injections have been used extensively to treat many tendon disorders including patellar tendinosis. Several studies have demonstrated the safety and efficacy of using PRP to treat patellar tendinosis.

One growth factor that is known to be helpful in tendon healing is insulin-like growth factor (IGF). However, IGF is not found in PRP but rather in the free plasma that is spun off during the PRP processing. This free plasma or platelet poor plasma (PPP) is typically discarded but it is a known source of IGF. We have shown that concentrating PPP in the FDA cleared Plasmax device yields an increased concentration of insulin-like growth factor (IGF). Local IGF injections into the patellar tendon have demonstrated improved tendon healing, but the effect on clinical outcomes has never been studied in a controlled fashion.

Research Design: Double blinded randomized comparative trial.

Detailed Study Procedures: 38 patients will be randomly assigned to a treatment arm. 19 patients will receive platelet rich plasma (PRP) and 19 patients will receive PRP plus concentrated IGF. Patient will be blinded to their treatment, but treatment team will not. PRP will be prepared according to standard sterile procedures out of view of the patient to ensure patients are adequately blinded. The injecting physician will not be blinded to randomization scheme.

Inclusion criteria

• >6 weeks of symptomatic patellar tendinosis
• unilateral or bilateral
• 18 yrs of age or older
• active in sport and exercise at least 3x / week
• able to take time away from sport (for healing and rehabilitation phase after procedure)
• failed at least 6 weeks of guided rehabilitation (under the supervision of either a certified athletic trainer or physical therapist)
• minimum Tegner activity level of 4

Exclusion criteria

• Steroid injection in target knee in the last 3 months
• PRP in the target knee in the last 6 months
• No other cellular treatments in index knee (bone marrow, amniotic suspensions) last 1 year
• Participation in any experimental device or drug study within 1 year before screening visit
• Oral or IM steroids for last 3 months
• Dry needling of patellar tendon in last 6 months