Peroneal tendinopathy

Anatomy: Which tendons are affected?

The peroneal tendons include the tendon of the peroneus (fibularis) brevis muscle and the tendon of the peroneus longus muscle. Both originate on the outside of the lower leg, run along a bony groove behind the outer malleolus (fibula) and are guided there by the upper peroneal tendon ligament (retinaculum). The peroneus brevis attaches to the outer edge of the foot (base of the 5th metatarsal bone); the peroneus longus runs further under the foot to the base of the first metatarsal bone. Their main function is eversion (elevation of the outer edge) and stabilization of the ankle joint, especially on uneven surfaces.

• Peroneus brevis: more commonly affected, typical so-called split tears along the lateral malleolus
• Peroneus longus: can be stressed by the os peroneum (a small sesamoid bone) or under the foot
• Retinaculum: important for leadership; Injuries can lead to tendon snapping or dislocation

Causes and risk factors

Peroneal tendinopathy usually occurs as a result of repeated overloading. Misalignments and instabilities also change the load distribution and promote microscopic damage to the tendon structure.

• Training and stress: rapid increase in running volume or jumps, training on sloping paths (curbside, beach), uneven terrain
• Previous injuries: repeated supination and twisting trauma with lateral ligament insufficiency
• Foot and leg axis: high arch of the foot or hindfoot varus (cavovarus) increases the load on the peroneal tendons
• Footwear: worn outsoles, lack of stability
• Anatomical factors: prominent peroneal tubercle, os peroneum, shallow retinaculum groove
• General factors: tendency to tendinopathy due to metabolic influences, rheumatism, hypercholesterolemia; Rarely medication aspects (e.g. fluoroquinolones) – individual clarification required

Typical symptoms

• Pain and tenderness behind or below the lateral malleolus
• Pain when walking on uneven surfaces, when pushing, climbing stairs or during lateral movements
• Start-up pain in the morning or after periods of rest, often improvement after a short warm-up
• Swelling or rubbing/creaking along the tendon, occasionally “snapping” if the tendon is unstable
• Reduced strength during eversion against resistance, unsteady feeling at the ankle

When should you seek medical advice?

• Acute “snapping” with painful swelling after twisting an ankle
• Marked weakness when lifting the outer edge of the foot
• Increasing pain at rest, significant redness/overheating
• Persistent symptoms despite rest for several weeks

Early diagnosis helps to avoid subsequent damage such as tendon tears or chronic instability.

Diagnostics: How we proceed

The diagnosis is based on anamnesis, targeted clinical examination and – if necessary – imaging procedures. It is crucial to recognize stress factors and accompanying problems such as ligament instability or incorrect statics.

• Clinical tests: palpation along the tendon path, pain provocation during eversion against resistance, assessment of ligament stability and foot axis
• Ultrasound (also dynamic): Depiction of tendon slippage, thickening, tenosynovitis, split tears and subluxations
• MRI: if symptoms persist, suspected high-grade tear, retinaculum injury or os peroneum syndrome
• X-ray: to rule out accompanying bony lesions and assess foot statics

Course and stages of tendinopathy

Tendinopathies often progress in phases. The classification helps to guide the therapy.

• Reactive phase: painful irritation after overload, usually without structural damage
• Dysrepair/degenerative: tendon thickening, fascicular remodeling processes, reduced resilience
• Partial tear/“split tear” of the peroneus brevis: longitudinal tears on the back of the outer malleolus
• Tendon subluxation/luxation: insufficient retinaculum, “snapping” behind the lateral malleolus
• Accompanying: tenosynovitis (tendonitis) with swelling and rubbing noise

Conservative therapy: step by step

In the vast majority, peroneal tendinopathy can be treated without surgery. The combination of load control, targeted physiotherapy, aids and patience is crucial. The specific plan is individually adapted to the findings and everyday requirements.

Additional procedures can be considered in individual cases if the basic therapy has been exhausted:

• Extracorporeal shock wave therapy (ESWT): can provide pain relief for chronic tendinopathy; Evidence for peroneal tendons is limited, benefit depends on the individual.
• Targeted infiltrations: Corticoids into the tendon sheath can reduce pain in the short term, but carry a risk to the tendon and are applied cautiously and not into the tendon.
• Autologous conditioned plasma (PRP): is sometimes used for treatment-resistant tendinopathy; The study situation for peroneal tendons is heterogeneous. Decision based on information about benefits/risks.

Time frame: With consistent conservative treatment, many cases improve within 6-12 weeks. In the case of degenerative changes, rehabilitation can take several months.

When does an operation make sense?

Surgical measures are considered if relevant symptoms persist for several months despite adequate conservative therapy or if there is structural damage that significantly impairs function.

• Higher grade partial tears or longitudinal split tears (especially peroneus brevis)
• Recurrent subluxation/dislocation of tendons due to retinaculum insufficiency
• Severe tenosynovitis with tendon strangulation
• Symptomatic os peroneum syndrome or prominent peroneal tubercle

Surgical procedures depend on the findings and include, for example: B. Debridement and tubularization of the tendon, retinaculum suture with groove deepening, synovectomy or - in the case of extensive damage - tenodesis (connecting the peroneus brevis/longus). The surgeon makes the decision based on imaging and clinical progress.

Rehabilitation after surgery: Initial partial weight-bearing in the orthosis/shoe, gradual mobilization and strength building. Return to running stress often after 3-4 months, sports with changes of direction more likely after 4-6+ months - depending on the individual healing process.

Self-help and exercises for everyday life

• Isometric eversion: press the foot outwards with Theraband, hold the tension for 30-45 seconds, 4-5 repetitions, 1-2 times a day adapted to pain.
• Eccentric training: Slowly release eversion against the band (3-4 seconds), 3 sets of 10-15 repetitions, 3-4 days/week.
• Calf and peroneal stretching: short, frequent stretches without severe pain; the tendon must not be “trained away”.
• Proprioception: Stand on one leg on a firm surface, later on a balance pad, 2-3 minutes on each side.
• Stress control: Pain as a guideline (during/24 hours afterwards not >3/10), gradual increase, plan rest days.
• Shoes: stable lateral support, replace worn soles in a timely manner; Avoid uneven, sloping terrain for the time being.

Prognosis and relapse prevention

With early diagnosis and consistent conservative treatment, the prospects are good. Decisive for lasting freedom from symptoms are a measured increase in load, addressed accompanying factors (e.g. ligament stability, foot statics) and regular strength and coordination training.

• Slow increase in volume and intensity
• Variability in training (strength, coordination, endurance)
• Individually fitted insoles/shoes
• Early countermeasures at the first warning signals

Differential diagnoses

• Lateral ligament lesions and chronic ankle instability
• Impingement syndromes of the lateral ankle joint
• Stress reaction/fracture on the 5th metatarsal ray
• Irritation of the plantar fascia with radiation (less often lateral)
• Nerve irritations (e.g. sural nerve) – to be differentiated

Your orthopedics in Hamburg

In our orthopedic practice at Dorotheenstrasse 48, 22301 Hamburg, we combine specialized examinations, high-resolution ultrasound and - if necessary - further imaging in order to specifically identify the causes of lateral ankle joint problems. We focus on structured, conservative treatment and accompany you through rehabilitation. Regenerative procedures or surgical options are only offered if there is a suitable indication and after transparent information.

Common misunderstandings

• “A lot helps a lot” is not true when it comes to tendons: building up the load too quickly delays healing.
• Pure protection without active development rarely leads to permanent improvement.
• Pain relief often occurs later than structural improvement - patience and progression are important.
• Cortisone is not standard: benefits and risks must be carefully weighed.