Peroneal tendon subluxation/tendinopathy

Anatomy: What do the peroneal tendons do?

The peroneal tendons are part of the muscles on the outside of the lower leg. The peroneus brevis and peroneus longus run behind the lateral malleolus (lateral malleolus) in a bony groove in the fibula and are held in position by a tight ligament, the upper peroneal retinaculum. Distally, the tendons pull along the outer edge of the foot; The peroneus longus moves to the inside of the sole of the foot and supports the transverse arch. There may be a small sesamoid bone (os peroneum) in the peroneus longus - a normal but sometimes pain-relevant finding.

• Function: eversion (outer edge raising) and plantar flexion of the foot
• Stabilization of the ankle joint, especially on uneven surfaces
• Dynamic support of longitudinal and transverse arches

What do subluxation and tendinopathy mean?

Peroneal tendon subluxation: When moving, the tendons slide out of the guide groove and spring back again. The cause is often a strain or tear in the retaining ligament (upper peroneal retinaculum) or a bone groove that is too shallow. Those affected often feel a distinct “snapping” behind the outer ankle.

Peroneal tendon tendinopathy: Non-inflammatory, painful-degenerative change in the tendon structure due to overloading, incorrect statics or recurring microtraumas. Stress-dependent pain on the outside of the foot, morning stiffness and pressure pain are typical. Both conditions can occur simultaneously; In addition, so-called “split tears” of the peroneus brevis (longitudinal partial tears) often occur.

Causes and risk factors

• Acute supination injury (folding outwards) with dorsiflexion: injury to the peroneal retinaculum
• Recurrent lateral ligament sprains with chronic instability
• Anatomical factors: shallow fibular groove, low-set muscle belly, additional tendon variant (peroneus quartus)
• Foot deformity: hollow foot/cavovarus (outer edge loading), rigid supination
• Overload due to running circumference, sloping or sandy ground, rapid changes of direction
• Unsuitable footwear without lateral support; worn outsoles
• Shortened calf muscles, neuromuscular deficits in the leg axis

Symptoms: How do I recognize it?

• Pain behind or below the outer ankle, sometimes radiating along the outer edge of the foot
• Snapping/“clicking” when moving or pushing off – indicates subluxation
• Swelling, occasionally rubbing/crunching (crepitus) along the tendon
• Stress-related complaints: stairs, uneven surfaces, changes in direction
• Morning stiffness, start-up pain; subjective instability at the ankle joint
• Peak pain with powerful eversion against resistance

When should you see a doctor?

• Acute “snapping” with subsequent swelling and feeling of instability after twisting an ankle
• Persistent pain > 2–3 weeks despite rest
• Significant weakness when lifting the outer edge (eversion) or visible tendon slipping
• Numbness, increasing pain at night or pain at rest

Diagnosis: Clinical examination and imaging

The diagnosis begins with anamnesis and functional examination: tenderness behind the lateral malleolus, pain with resistant eversion and in combined dorsiflexion/eversion are typical. A provocative maneuver can trigger the subluxation and reproduce the snapping. We also check the ankle ligaments, leg axis and foot statics (e.g. hollow foot).

• Ultrasound (dynamic): shows tendon structure, sliding behavior and inflammation of the tendon sheath in real time
• MRI: Assessment of tendon tears, retinaculum, bony groove and accompanying pathologies
• X-ray: exclusion of bony avulsions, assessment of the axis; Representation of an os peroneum possible

Differential diagnoses that we consider and, if necessary, exclude:

• Lateral ligament instability/sinus tarsi syndrome
• Osteochondral lesion of the talus, stress reaction on the 5th metatarsal bone
• Achilles tendon and heel attachment problems (e.g. Haglund, retrocalcanear - see links)
• Medial/plantar nerve entrapment syndromes with radiating pain

Conservative therapy: step-by-step plan

Our principle: conservative before operational. Most tendinopathies and a large proportion of subluxations can be significantly improved through a structured approach. The therapy plan depends on the duration of the symptoms, activity and accompanying factors.

In the case of acute, first-time subluxation, immobilization in a cast with slight plantar flexion/eversion for 4–6 weeks can be considered. The risk of recurrence is increased in patients who are very active in sports; The course and objectives are discussed in detail here.

Additional and regenerative processes: What is proven?

In addition to basic therapy, additional procedures may be considered in selected cases. Data specifically for peroneal tendons is limited; we provide transparent advice about benefits and limitations.

• Shock wave therapy (ESWT): proven for various tendinopathies; Small but plausible benefit for peroneal tendons. Use individually.
• Ultrasound-targeted injection into the tendon sheath to reduce inflammation can be considered. Injections into the tendon itself are avoided.
• PRP (platelet-rich plasma): An option for chronic courses; Evidence heterogeneous. Decision made after informed consent and indication review.

When does an operation make sense?

Surgery is considered if consistent conservative therapy over several weeks to months does not bring sufficient improvement, if there is persistent mechanical instability (recurrent tendon slippage) or if there are relevant types of tears. The decision is always made individually after information about alternatives, opportunities and risks.

• Reconstruction/refixation of the upper peroneal retinaculum
• Deepening of the fibular groove (groove depression) when the bone is flat
• Debridement and tubularization for longitudinal tears (especially peroneus brevis), if necessary tenodesis for tendons that cannot be preserved
• Removal of a painful os peroneum with tendon reconstruction, tenosynovectomy

Follow-up treatment: There is usually a phase of immobilization with gradual increase in load and physiotherapy. A return to running stress is often possible after around 10-12 weeks, sport-specific stress with changes of direction later. Courses vary depending on the procedure and initial findings.

Course and prognosis

Many patients achieve a significant reduction in symptoms and an increase in stress with consistent, well-controlled conservative therapy. If there is severe mechanical instability or structural cracks, the chances of lasting freedom from symptoms are conservatively limited - then a surgical procedure may make sense. Early diagnosis and addressing risk factors (e.g. cavus foot static, instability) improve the outlook.

Prevention and self-management

• Warm-up and lateral ankle stabilization (balance and jumping exercises) 2–3 times/week
• Footwear with stable heel support; Replace worn outsoles in a timely manner
• Insole supply for cavovarus/hollow foot to distribute the load (adjust individually)
• Increase running volume and intensity gradually; Avoid cambery roads
• maintain calf mobility; regular stretching and eccentric programs
• Early rehabilitation after twisting trauma to avoid recurrences

What you can do yourself – practical tips

• Orient stress to pain: 0–3/10 tolerable, avoid sustained increase
• Cool 10-15 minutes after exercise, compression during the day if swelling occurs
• Daily, short exercise sessions are more effective than infrequent, long ones
• If you notice a “snapping” sensation, do not change direction quickly; Use stabilization orthosis
• Early feedback to therapy if pain increases or new symptoms appear

Your treatment in Hamburg

In our orthopedic specialist practice at Dorotheenstrasse 48, 22301 Hamburg, you will receive a structured assessment and a therapeutic strategy that exhausts conservative options and only uses regenerative procedures if there is a clear indication. If necessary, we will plan further surgical treatment and subsequent rehabilitation with you.

Related hindfoot diseases

Pain in the hindfoot area can have various causes and overlap. These topics might also be relevant to you:

• Tibialis posterior insufficiency (medial tendon problems, flattening of the arch of the foot)
• Tarsal tunnel syndrome (nerve constriction on the inside of the foot)
• Baxter neuropathy (plantar nerve, often involved in heel pain)
• Haglund exostosis and retrocalcaneal bursitis (pain in the Achilles tendon/heel area)
• Achilles tendon rupture (sudden event with loss of function)