Short-term outcomes of two PRP-based treatment protocols for Stoller grade I-II meniscal lesions: serial ultrasound-guided perimeniscal PRP injections versus arthroscopic management with a single intra-operative intra-articular PRP injection.

OBJECTIVE: To describe and contrast short-term clinical outcomes associated with two routinely used treatment protocols for symptomatic Stoller grade I-II meniscal lesions: (i) serial ultrasound-guided perimeniscal PRP injections and (ii) arthroscopic management with a single intra-operative intra-articular PRP injection.

METHODS: We retrospectively reviewed patients treated between September 2023 and December 2024. Protocol A comprised serial ultrasound-guided perimeniscal PRP injections (5 mL per session; three sessions over 6 weeks). Protocol B comprised arthroscopic meniscus management as indicated (debridement/repair) combined with a single intra-operative intra-articular PRP injection (5 mL). Outcomes were VAS, Lysholm, and Japanese Orthopedic Association (JOA) scores at baseline and at 1, 3, and 6 months. Linear mixed-effects models included treatment protocol, time, and their interaction as fixed effects and subject-specific random intercepts, with additional adjustment for age, sex, BMI, and Stoller grade.

RESULTS: Forty patients were included (20 per protocol), and no serious complications occurred. Linear mixed-effects model analysis revealed that both groups demonstrated significant improvement over time. The VAS scores significantly decreased at all follow-ups (e.g., mean reduction of 4.85 points at 6 months; 95% CI: -5.15 to -4.55; P < 0.001), while Lysholm (mean increase of 26.2 points; 95% CI: 25.35 to 27.05) and JOA scores (mean increase of 21.55 points; 95% CI: 20.67 to 22.43) significantly increased (all P < 0.001). Analysis of the group × time interaction suggested different Lysholm trajectories between Protocol A and Protocol B, with higher model-estimated Lysholm scores for Protocol B at 6 months; these between-protocol contrasts are descriptive and hypothesis-generating.

CONCLUSION: In this retrospective cohort of symptomatic Stoller grade I-II meniscal lesions, both protocols were associated with substantial short-term improvements in pain and knee function over 6 months. Pain trajectories (VAS) did not differ between protocols, whereas Protocol B showed higher model-estimated functional scores (Lysholm and JOA) at 6 months. These between-protocol patterns are descriptive and hypothesis-generating only, because the protocols differed simultaneously in surgical intervention, PRP dosing schedule, injection route/target, and postoperative management. Therefore, the present design does not permit isolation of the independent effect of PRP itself or attribution of the observed differences to any single treatment component. Future adequately powered prospective trials with standardized PRP characterization and blinded outcome assessment should test whether an arthroscopy-based protocol yields greater functional recovery, while prioritizing prespecified functional and imaging endpoints.