JSES - 2026-04-08 - Journal Article
Morphological changes in tennis elbow after PRP injection: A novel MRI-based assessment in a randomized controlled study.
Walecka J, Dzianach M, Rachwal-Czyzewicz I, Ringwelska Z, Lubiatowski P
Topics
Key Takeaway
LR-PRP reduced partial CET tear size and soft tissue edema more than saline, but neither PRP formulation demonstrated overall superiority to saline injection at 6-month MRI follow-up in a double-blind RCT of 71 patients.
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Summary
This double-blind RCT compared LR-PRP, LP-PRP, and saline injection in 71 patients with chronic lateral epicondylar tendinopathy, using 3T MRI in the Superman position as the primary outcome tool with ICC >0.90 reliability. All three groups showed statistically significant improvement in tendon structure and muscle edema at 6 months. LR-PRP demonstrated advantages in partial tear size reduction and soft tissue edema, but no formulation achieved overall superiority over saline for tendinosis resolution or muscle edema.
Key Limitation
The study lacks patient-reported functional outcomes, making it impossible to determine whether MRI-detected morphological differences between LR-PRP and saline translate into clinically meaningful symptomatic or functional benefit.
Original Abstract
BACKGROUND
Lateral epicondylar tendinopathy (tennis elbow) is a degenerative tendinopathy of the common extensor tendon (CET), often affecting individuals engaged in repetitive upper-limb activities. While clinical diagnosis is standard, MRI enables an objective assessment of tendon pathology and treatment response. This randomized controlled trial aimed to evaluate the effect of platelet-rich plasma injections on tendon healing in lateral epicondylar tendinopathy using MRI. The primary outcome was the reduction in partial tendon tear size measured on MRI.
METHODS
A double-blind, randomized, placebo-controlled study was conducted on 71 patients with chronic lateral tendinopathy. MRI scans were performed using a 3T scanner in the "Superman position," assessing CET integrity, tendon tears, soft tissue edema, and collateral ligament abnormalities. Patients received either leukocyte-rich PRP (LR-PRP), leukocyte-poor PRP (LP-PRP), or saline injections. Another MRI was performed at six months following injections. Interobserver reliability was measured using the intraclass correlation coefficient (ICC).
RESULTS
The MRI protocol demonstrated excellent reliability (ICC > 0.90). Statistically significant improvements in tendon structure and muscle edema were observed in all treatment groups, including saline. However, LR-PRP showed a distinct advantage in reducing partial tendon tear size and soft tissue edema, while LP-PRP also led to some improvement in soft tissue morphology, though less consistently. Joint effusion was less frequent in both PRP groups compared to control. No significant superiority of PRP over saline was observed in tendinosis resolution or muscle edema reduction at six-month follow-up.
CONCLUSION
This study presents a reproducible MRI-based assessment technique for lateral tendinopathy, enhancing diagnostic precision and treatment evaluation. It confirmed a wide dynamicly changing spectrum of pathologies, not strictly limited to tendinopathy (e.g., edema, effusion, synovitis, tendon tears, ligament abnormalities, subchondral cysts). Clearly soft tissue morphology improved with the treatment. While PRP treatments - particularly LR-PRP - offered benefits in specific morphological parameters such as tear size and soft tissue edema, overall improvement patterns suggest that PRP was not universally superior to saline. MRI remains a valuable tool for monitoring structural tendon changes in chronic lateral tendinopathy.