Common tendon sheath of fibularis muscles

Looks like

One sleeve around both fibularis tendons as they curve behind the outer ankle bone.

What it does

Lets the two tendons glide in their groove under a retaining band.

Keeping it well

Tenosynovitis or tears cause swelling behind the outer ankle; ultrasound shows it.

Related conditions

• Buerger's disease (thromboangiitis obliterans)
• Chronic venous insufficiency
• Clubfoot (talipes equinovarus)
• Flat feet (pes planus)
• Ganglion cyst
• Gout
• Haemophilia & bleeding disorders
• Hammer toe and claw toe
• Lyme disease
• Lymphatic filariasis (elephantiasis)
• Lymphoedema
• Marfan syndrome & connective tissue disorders
• Morton's neuroma
• Osteoarthritis
• Psoriatic arthritis
• Restless legs syndrome
• Rheumatic fever & rheumatic heart disease
• Rheumatoid arthritis
• Systemic lupus erythematosus
• Temporomandibular joint disorder
• Varicose veins
• Venomous snakebite