PRP for Grade 2 LCL Tear: Clinical Recommendation
Based on current evidence, PRP therapy is a reasonable treatment option for grade 2 lateral collateral ligament tears, particularly when combined with structured rehabilitation, though the evidence base is limited to case reports and extrapolation from similar ligamentous injuries.
Evidence Quality and Guideline Framework
The International Society on Thrombosis and Haemostasis rates PRP for sports injuries as uncertain (median score 5.5/9), reflecting the lack of high-quality controlled trials for ligamentous injuries 1. However, this uncertainty stems primarily from poor standardization of PRP preparations rather than evidence of ineffectiveness 1.
Supporting Evidence from Similar Ligamentous Injuries
Strongest Direct Evidence
- Single case report: An active-duty soldier with isolated LCL injury treated with PRP demonstrated substantial improvement in recovery speed and strength outcomes, supporting early PRP use in similar cases 2.
Extrapolation from Comparable Injuries
- Ulnar collateral ligament (UCL) data: Grade 2 (high-grade partial) tears treated with PRP showed 61.5% return-to-play without surgery, with MRI-confirmed ligament reconstitution 3, 4.
- ACL partial tears: 96% of patients achieved ligament continuity on MRI and returned to sport after PRP therapy, with average 2.8 sessions 5.
- Ankle ATFL grade 2 tears: Two PRP injections produced significantly better clinical outcomes and ligament quality on MRI compared to conservative treatment alone 6.
Clinical Protocol Based on Best Available Evidence
Treatment Algorithm
- Timing: Initiate PRP within 6 weeks of injury 7, 5
- Dosing: Plan for 2-3 PRP sessions, separated by 2-4 weeks 3, 5, 6
- Delivery: Use ultrasound guidance for accurate injection into the tear site 7, 6
- Immobilization: Consider 2 weeks of bracing that limits varus stress but allows weight-bearing 3, 6
- Rehabilitation: Combine with structured physical therapy—PRP alone is insufficient 7, 2
- Follow-up imaging: Obtain MRI at 8 weeks to assess ligament reconstitution 3, 6
Expected Outcomes
- Return to sport typically occurs at 3-5 months (average 82-139 days based on UCL/ACL data) 3, 5
- MRI should demonstrate ligament continuity before full return to activity 3, 5
- Re-rupture risk exists even with apparent healing—set realistic expectations 7
Critical Caveats
Preparation Standardization Issues
- PRP preparations vary widely in platelet concentration, purity, and activation status, directly impacting efficacy 1, 7. Ensure your facility uses leukocyte-rich PRP with documented platelet concentration 3.
When PRP May Fail
- Prior surgery: PRP appears less effective in patients with previous ligament surgery (0% success in UCL revision cases) 3, 4.
- Complete tears with multiple locations: Type IV tears (multiple tear sites) showed only 12.5% success with PRP 4.
Safety Profile
- PRP is clinically safe when prepared using sterile autologous technique, with minimal immunogenicity risk 1, 7.
Practical Implementation
If proceeding with PRP for grade 2 LCL tear:
- Verify the injury is truly grade 2 (partial tear) on MRI—complete tears may require surgical consideration
- Use 2 injections minimum, spaced 2-4 weeks apart
- Implement concurrent varus-limiting brace and structured PT
- Reassess clinically and with MRI at 8 weeks before advancing rehabilitation
- Target return to full activity at 3-4 months, not earlier
The evidence supporting PRP for LCL specifically is minimal (one case report), but the biological rationale and success in analogous grade 2 ligamentous injuries (UCL, ACL, ATFL) provides reasonable justification for its use 3, 5, 4, 2, 6.