Lateral Patellar Retinaculum

retinaculum patellae laterale

The lateral patellar retinaculum is the fibrous expansion on the lateral side of the knee joint connecting the lateral patellar border to the iliotibial band, the lateral intermuscular septum, and the lateral tibial condyle. It has two distinct layers: the superficial oblique layer (from the IT band to the patella) and the deep transverse layer (from the lateral epicondyle to the lateral patella — the lateral epicondylropatellar ligament, LEPL). The deep transverse layer is the primary lateral restraint to medial patellar translation.

Region: Knee

Clinical Relevance

Clinical Notes

Lateral retinaculum tightness is a major contributor to patellar tilt and patellofemoral pain syndrome. Lateral release divides the lateral retinaculum (open or arthroscopic) to allow medial patellar translation and correct lateral tilt. The deep transverse layer (LEPL) is the primary target: its release is sufficient in most cases; over-aggressive release extending into the IT band or the vastus lateralis fascia risks medial patellar instability. Lateral retinaculum tightness is assessed by the patellar tilt test (less than 0 degrees tilt indicates a tight lateral retinaculum requiring release).

Pathology

Common Injuries & Conditions

Lateral Retinaculum Tightness Causing Patellar Tilt in PFPS

Tight lateral patellar retinaculum tilts the patella laterally in the trochlear groove increasing lateral facet contact pressure and producing lateral patellar facet articular cartilage damage over time; lateral retinaculum release allowing patellar neutral tilt reduces lateral compartment pressure and is combined with medial quadriceps strengthening for patellofemoral pain syndrome.