Morphological changes in tennis elbow after PRP injection: a novel MRI-based assessment in a randomized controlled...

Area of Science:

• Orthopedics
• Radiology
• Regenerative Medicine

Background:

• Lateral epicondylar tendinopathy, commonly known as tennis elbow, is a degenerative condition of the common extensor tendon (CET).
• Clinical diagnosis is standard, but Magnetic Resonance Imaging (MRI) offers objective assessment of tendon pathology and treatment efficacy.
• This study utilized MRI to evaluate the impact of platelet-rich plasma (PRP) injections on tendon healing in patients with lateral epicondylar tendinopathy.

Purpose of the Study:

• To assess the effect of leukocyte-rich PRP (LR-PRP), leukocyte-poor PRP (LP-PRP), and saline injections on tendon healing in chronic lateral tendinopathy using MRI.
• To determine the primary outcome of reduction in partial tendon tear size as measured by MRI.
• To establish a reproducible MRI-based assessment technique for evaluating pathologies and treatment response in lateral tendinopathy.

Main Methods:

• A double-blind, randomized, placebo-controlled trial involving 71 patients with chronic lateral tendinopathy.
• MRI scans were performed using a 3T scanner in the "Superman position" to evaluate CET integrity, tears, edema, and collateral ligament abnormalities.
• Patients received either LR-PRP, LP-PRP, or saline injections, with follow-up MRIs at six months. Interobserver reliability was assessed using the intraclass correlation coefficient (ICC).

Main Results:

• The MRI protocol demonstrated excellent interobserver reliability (ICC > 0.90).
• Statistically significant improvements in tendon structure and muscle edema were observed across all groups, including saline.
• Leukocyte-rich PRP (LR-PRP) demonstrated a distinct advantage in reducing partial tendon tear size and soft tissue edema, while LP-PRP showed less consistent improvements. Joint effusion was less frequent in PRP groups compared to saline. No significant superiority of PRP over saline was found for tendinosis or muscle edema at six months.

Conclusions:

• A reproducible MRI-based assessment technique for lateral tendinopathy was established, improving diagnostic precision and treatment evaluation.
• The study identified a dynamic spectrum of pathologies beyond tendinopathy, including edema, effusion, synovitis, tears, ligament abnormalities, and cysts.
• While PRP, especially LR-PRP, offered specific morphological benefits (tear size, edema), it was not universally superior to saline, highlighting MRI's value in monitoring structural tendon changes.