Excessive lateral pressure syndrome (ELPS) is a collection of symptoms and signs related to the edge of the kneecap being forced abnormally against the wall of the underlying groove.
Page updated February 2024 by Dr Sheila Strover (Clinical Editor)
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
Cartilage damage from ELPS
Anterior knee pain is experienced, which 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.
"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"
Citation: Wang CL, Chen JB, Li T. Outcome and experience of arthroscopic lateral retinacular release combined with lateral patelloplasty in the management of excessive lateral pressure syndrome. J Orthop Surg Res. 2021 Jan 22;16(1):80. doi: 10.1186/s13018-021-02229-4. PMID: 33482854; PMCID: PMC7821727.