ACL Sprain or Tear

Evidence: Not Typically Recommended — ASPN 2024: Not a graded standalone indication

CAUSES

• Sudden pivoting or changing direction with the foot planted (like during soccer, basketball, skiing)
• Landing awkwardly from a jump
• Trauma to the outer knee
• Sudden deceleration or hyperextension of the knee

SYMPTOMS

• A loud “pop” felt or heard during injury
• Rapid swelling within the first few hours
• A feeling that the knee is unstable or “gives way,” especially with pivoting
• Pain and difficulty bearing weight right after the injury
• Loss of range of motion

IMAGING

MRI is the standard for confirming an ACL tear, telling whether it is partial or complete, and checking for associated meniscus or cartilage injury. X-rays will help rule out a fracture.

CAN PRP HELP?

PRP is not a substitute for the structural stability the ACL provides. A complete tear requires surgical evaluation. Even for a partial, stable tear managed without surgery, PRP has only been studied as an additive around the time of surgical repair.

Leukocyte Preparation: Not applicable

Dosing: No protocol recommended

ASPN 2024 CONSENSUS GUIDELINE

ASPN’s 2024 consensus guideline addresses the ACL only in the context of PRP as surgical augmentation used at the time of reconstruction, rating that specific use Level II-1, Grade D — not routinely recommended, since most systematic reviews show no meaningful difference in graft healing or outcomes versus surgery alone. An August 2025 AAOS guideline update goes further, explicitly restricting PRP and marrow-stimulation techniques as adjuncts during ACL and rotator cuff repair surgery. Isolated, non-surgical PRP injection into a sprained or partially torn ACL falls outside ASPN’s graded indications altogether — there is no controlled evidence to support it as a stand-alone treatment. A suspected ACL injury, especially with instability, should be evaluated by an orthopedic surgeon before any injection is considered.

Sources: D’Souza et al. (ASPN Consensus), Journal of Pain Research, 2024 · AAOS Clinical Practice Guideline (soft-tissue surgical augmentation update), 2025

FREQUENTLY ASKED QUESTIONS

Can a PRP injection help me avoid ACL reconstruction surgery?

No. A complete ACL tear that causes instability typically requires surgical reconstruction, and no injection can restore the mechanical stability the ligament provides. PRP is not a substitute for that structural repair.

What about using PRP during ACL surgery itself — does that help the graft heal?

That’s the only setting ASPN has actually graded, and the answer there is also cautious. PRP as a surgical adjunct at the time of reconstruction rates Level II-1, Grade D — not routinely recommended, since most systematic reviews show no meaningful difference in graft healing versus surgery alone. A 2025 AAOS guideline update goes further, explicitly restricting PRP as an adjunct during ACL and rotator cuff repair surgery.

Is there any role for PRP in a partial, stable ACL tear managed without surgery?

Evidence at this time suggests only as an add-on studied around the time of surgical repair and not as a stand-alone treatment for the ligament itself. There is currently no controlled evidence supporting an isolated PRP injection into a sprained or partially torn ACL, so any suspected ACL injury, especially with instability, should be evaluated by an orthopedic surgeon first.