Posterior Meniscofemoral Ligament (Wrisberg): Anatomy, Attachments, Relations, Function, MRI & CT Imaging

Topic

Posterior meniscofemoral ligament

The posterior meniscofemoral ligament, also known as the ligament of Wrisberg, is one of the meniscofemoral ligaments of the knee. It arises from the posterior horn of the lateral meniscus and courses superior and medial to the posterior cruciate ligament (PCL) before inserting into the medial femoral condyle.

This ligament plays an important role in stabilizing the posterior horn of the lateral meniscus and contributes to posterior knee stability alongside the PCL. It is variable in presence, found in approximately 70% of knees (either alone or with the anterior meniscofemoral ligament, Humphrey’s ligament).

Synonyms

Ligament of Wrisberg
Posterior meniscofemoral ligament (PMFL)
Posterior meniscus-femoral ligament

Origin and Insertion

Origin: Posterior horn of the lateral meniscus
Course: Passes obliquely upward and medially, running posterior to the posterior cruciate ligament
Insertion: Lateral aspect of the medial femoral condyle, near the femoral attachment of the PCL

Relations

Anteriorly: Posterior cruciate ligament (PCL)
Posteriorly: Posterior capsule of the knee joint
Laterally: Posterior horn of the lateral meniscus and lateral femoral condyle
Medially: Medial femoral condyle and adjacent portion of the PCL

Nerve Supply

Supplied by articular branches from the posterior articular nerve (branch of tibial nerve)

Arterial Supply

Supplied by branches of the middle genicular artery

Venous Drainage

Venous return via genicular veins → popliteal vein

Function

Stabilizes the posterior horn of the lateral meniscus
Supports the posterior cruciate ligament in preventing posterior translation of the tibia
Contributes to the rotational stability of the knee joint
Helps distribute and balance joint forces in flexion and rotation

Clinical Significance

May mimic or be confused with the PCL on imaging
Injury may accompany PCL or lateral meniscus tears
Important in meniscal root repair and PCL reconstruction surgery
Can be mistaken for a torn meniscal fragment on MRI if not identified

MRI Appearance

T1-weighted images:

Ligament appears as a thin low-signal band posterior to the PCL
Surrounded by high-signal fat, which provides contrast

T2-weighted images:

Appears as a dark, linear low-signal band posterior to the PCL
Tears or degeneration show focal areas of bright hyperintensity

STIR (Short Tau Inversion Recovery):

Normal ligament remains low signal
Pathology (strain, tear, edema) appears bright

Proton Density Fat-Saturated (PD FS):

Ligament shows low signal in normal state
Pathological changes (partial tear, inflammation) demonstrate bright hyperintense signal

T1 Fat-Sat Post-Contrast:

Normal ligament shows little to no enhancement
Injured or inflamed ligament may show mild enhancement at attachment sites

CT Appearance

Non-Contrast CT:

Ligament not well visualized directly; inferred by soft tissue density near PCL
May be identified on high-resolution CT arthrography as a fine band posterior to PCL

Post-Contrast CT:

Normal ligament does not enhance significantly
CT arthrography may show the ligament as a thin linear structure posterior to the PCL
Pathology may be seen as irregularity, thickening, or discontinuity

MRI images