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Head of fibula

The head of the fibula is the expanded proximal end of the fibula, located on the lateral side of the knee. It articulates with the lateral condyle of the tibia via the proximal tibiofibular joint and serves as an important site for multiple muscular and ligamentous attachments. The fibular head plays a key role in lateral knee stability and lower limb biomechanics.

Clinically, it is an important landmark because of its close relationship with the common peroneal nerve, which winds around it, making it vulnerable to compression or injury.

Synonyms

  • Proximal fibular head

  • Fibular head

  • Caput fibulae

Muscular Attachments

  • Biceps femoris tendon inserts onto the lateral aspect of the fibular head

  • Fibular collateral ligament (LCL): attaches to the fibular head, contributing to lateral knee stability

  • Soleus muscle: originates partly from posterior fibular head

  • Peroneus (fibularis) longus muscle: originates partly from lateral aspect of fibular head

Relations

  • Anteriorly: Tibialis anterior and proximal tibiofibular joint

  • Posteriorly: Popliteus muscle and soleus origin

  • Medially: Lateral condyle of tibia (articulation site)

  • Laterally: Common peroneal nerve winding around fibular neck, then dividing into superficial and deep peroneal nerves

  • Superiorly: Lateral collateral ligament of the knee

  • Inferiorly: Continuation into the fibular shaft

Function

  • Provides structural support and serves as an articulation site with tibia (proximal tibiofibular joint)

  • Acts as an attachment site for muscles and ligaments involved in knee stability and ankle movement

  • Helps transmit forces between the tibia, knee, and ankle

  • Protects and guides the course of the common peroneal nerve

Clinical Significance

  • Fractures: Common in knee trauma, often associated with ligamentous injuries

  • Nerve injury: Common peroneal nerve is vulnerable at fibular neck → foot drop

  • Bursitis: Fibular head bursa inflammation may mimic lateral knee pain

  • Surgical landmark: Used in knee arthroplasty, ligament reconstruction, and peroneal nerve decompression

MRI Appearance

T1-weighted images:

  • Bone marrow of fibular head shows intermediate-to-bright signal

  • Muscular and ligamentous attachments appear as low-signal structures

T2-weighted images:

  • Marrow signal is intermediate-to-bright

  • Cortical bone appears dark

  • Joint fluid or edema appears bright

STIR (Short Tau Inversion Recovery):

  • Normal marrow signal is low

  • Pathology (edema, fracture, tumor, infection) appears as bright hyperintensity

Proton Density (PD):

  • Marrow signal is intermediate-to-bright

  • Useful for assessing cartilage, joint, and marrow abnormalities

Proton Density Fat-Saturated (PD FS):

  • Normal marrow is low signal after fat suppression

  • Pathological changes (edema, inflammation, tumor) appear bright

T1 Fat-Sat Post-Contrast:

  • Normal marrow enhances mildly and uniformly

  • Abnormal marrow (tumor, infection, inflammation) shows heterogeneous or focal enhancement

  • Soft tissue extension or synovial pathology may enhance vividly

CT Appearance

Non-Contrast CT:

  • Shows cortical bone as dense white structure with well-defined trabecular marrow pattern

  • Fractures, lytic lesions, or sclerotic changes can be clearly identified

  • Soft tissues and peroneal nerve course less well visualized compared to MRI

Post-Contrast CT:

  • Cortical bone does not enhance

  • Adjacent soft tissues may show enhancement in infection, inflammation, or tumor infiltration

  • Vascularized lesions of fibular head may show enhancement in marrow or periosteum

MRI image

Head of fibula axial cross sectional anatomy 3T MRI AI enhanced radiology anatomy image-img-00000-00000

MRI image

Head of fibula coronal cross sectional anatomy 3T MRI AI enhanced radiology anatomy image-img-00000-00000

MRI image

Head of fibula sag cross sectional anatomy 3T MRI AI enhanced radiology anatomy image-img-00000-00000

CT image

Head of fibula ct axial

CT image

Head of fibula ct coronal image

CT image

Head of fibula ct sag image