EpistemisPain in the peroneal tendon sheath
Specialty: Musculoskeletal.
Why it occurs
- Mechanical overload due to repeated ankle sprains (chronic lateral ankle instability)
- Subluxation of the peroneal tendons due to rupture or laxity of the superior peroneal retinaculum
- Cavo-varus foot (which increases tension on the external column of the foot)
- Microtears or longitudinal tear of the peroneus brevis tendon
- Running on uneven terrain or hills
- Worn out footwear that promotes supination
Initial workup
Dynamic ultrasound of the lateral ankle (allows evaluation of the sliding and stability of the long and short peroneal tendons with respect to their retro-malleolar canal) | Ankle MRI (identifies longitudinal intrasubstance tears and tenosynovitis) | AP and lateral x-ray of the ankle.
red flags
Very acute external retro-malleolar pain after forced ankle sprain, with an audible crunch, visible deformity with the tendons moving in front of the external malleolus when performing active eversion (acute subluxation of peroneal tendons, requires surgical repair of the retinaculum).
Standard management
- Dexketoprofen — 25 mg every 8 hours orally for 5 days to control the acute inflammatory phase
- Paracetamol — 1 g every 8 hours orally as rescue
- Ultrasound-guided infiltration of methylprednisolone (10-20 mg directed precisely to the interior of the peroneal tendon sheath, avoiding direct intratendinous injection).
Educational guidance for study. It is NOT a prescription recommendation. The actual choice depends on the cause, the patient, and current guidelines.
- Area
- Musculoskeletal
- Listed causes
- 6
- Treatment options
- 3