PCL Sprain or Tear

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

CAUSES

• A direct blow to the front of the shin just below the knee while it’s bent — the classic “dashboard injury” in a car crash
• Falling hard onto a bent knee
• Hyperflexion or hyperextension of the knee during sports
• Often occurs alongside other ligament injuries in high energy trauma

SYMPTOMS

• Deep, aching pain at the back of the knee, often less dramatic than the sudden “pop” typical of an ACL injury
• Mild to moderate swelling
• A vague sense of instability, especially walking downhill or downstairs
• Stiffness and difficulty fully bending the knee
• A positive “sag sign” on exam, where the shin drops backward with the knee bent

IMAGING

MRI of the knee without contrast confirms a PCL tear, grades its severity, and helps detect potential other ligament or cartilage. X-ray can also rule out a fracture.

CAN PRP HELP?

PRP does not restore the mechanical stability a torn PCL normally provides. Low-grade, isolated PCL sprains are often managed conservatively with bracing and physical therapy regardless of any injection, while higher-grade or combined-ligament injuries usually need surgical evaluation. There is no meaningful body of evidence studying PRP as a stand-alone treatment for a PCL injury.

Leukocyte Preparation: Not applicable

Dosing: No protocol recommended

ASPN 2024 CONSENSUS GUIDELINE

ASPN’s 2024 consensus guideline does not include a graded indication for PCL injury. The nearest related evidence is the guideline’s Level II-1, Grade D rating for PRP as a surgical augmentation adjunct during other ligament and tendon repairs — a different clinical scenario, and one the panel does not recommend. We list PCL sprain here to be transparent that we don’t have supportive evidence for injecting it, not to suggest ASPN formally weighed in and said no. Suspected PCL injury, particularly with instability or a positive sag sign, should be evaluated by an orthopedic surgeon.

Sources: D’Souza et al. (ASPN Consensus), Journal of Pain Research, 2024

FREQUENTLY ASKED QUESTIONS

Is a PCL tear treated the same way as an ACL tear?

Low-grade, isolated PCL sprains are often managed conservatively with bracing and physical therapy regardless of any injection, while higher-grade or combined-ligament injuries usually need surgical evaluation. Injuries to the PCL more often cause a vague sense of instability rather than the sudden pop typical of an ACL tear.

Can a PRP injection strengthen a stretched or partially torn PCL?

There isn’t a meaningful body of evidence studying PRP as a stand-alone treatment for a PCL injury. As with the ACL, PRP does not restore the mechanical stability the ligament normally provides. ASPN’s 2024 guideline doesn’t include a graded indication for PCL injury at all.

How is a suspected PCL injury diagnosed?

MRI of the knee without contrast confirms a PCL tear, grades its severity, and helps detect the other ligament or cartilage injuries that often accompany higher-energy PCL trauma. A standing knee X-ray is typically obtained first to rule out a fracture. A positive “sag sign,” where the shin visibly drops backward with the knee bent, is a classic exam finding.