Cartilage damage may occur on the lateral side from the increased pressure
What causes ELPS?
Abnormal patellar tilt is the underlying condition that leads to the pain. Note that the patella is simply tilted and not actually shifted to the side.
The tilt is associated with tight lateral soft tissue structures - the lateral retinaculum - but whether this is cause or effect is not established.
This may put strain on the medial side and tenderness in the region of the medial patellofemoral ligament (MPFL).
Tight lateral structures or muscle imbalance may lead to tilt of the patella to the lateral side.
"Excessive lateral pressure syndrome (ELPS)....is featured by long-term lateral tilt of the patella without subluxation or dislocation and adaptive shortening of lateral retinaculum (LR), which results in long-term stress imbalance of the medial and lateral patellofemoral articular surface, increased lateral patellofemoral joint pressure, and ultimately causes a series of pain syndromes"
Cartilage damage from ELPS
Pain in the front of the knee tends to worsen as contact pressure increases when the knee is flexed.
Over time the adjacent lateral patella and lateral femoral condyle may show damage to the joint cartilage and underlying bone.
Tight lateral structures or muscle imbalance may lead to tilt of the patella to the lateral side.
Cartilage damage may occur on the lateral side from the increased pressure
Other relevant links
Patellar tilt, Patellar tilt test, MPFL, Articular cartilage, Cartilage damage
Forum discussions
- "Re: Need Advice Please!" - A discussion about lateral release in various patellofemoral scenarios.