Peroneal tendon disorders are a cause of hindfoot and lateral foot pain. There are three primary disorders of the tendons; peroneal tendonitis, peroneal subluxation, and peroneal tendon tears; these conditions are a cause of lateral ankle pain and may lead to ankle instability. The peroneal tendons are in the lateral compartment of the leg and include the peroneus longus and peroneus brevis muscles. Both receive innervation from the superficial peroneal nerve and blood supply from the peroneal artery. The peroneus brevis originates on the lateral aspect of the distal fibula and intermuscular septum and inserts onto the base of the fifth metatarsal. The peroneus longus originates at the proximal fibula and lateral tibia and inserts at the base of the first metatarsal and the medial cuneiform. The tendons occupy a common synovial sheath that runs posterior to the distal fibula, once past the fibula they each have their own synovial sheath. They run in a tunnel bordered by the superior peroneal retinaculum, the posterior fibula that has a trimalleolar groove, and the calcaneofibular ligament.[rx] The tendon relationship at the level of the ankle is the peroneus brevis anterior and medial to the peroneus longus.[rx]
Anatomy of Peroneus
Peroneus Longus
- Origin – The peroneus longus muscle originates on the head of the fibula and the upper half of the fibular shaft – this muscle crosses the ankle joint and courses deep into the foot and passes into a groove of the cuboid bone.
- Insertion – the posterolateral aspect of the medial cuneiform bone and the lateral portion of the base of the first metatarsal
- Action – The peroneus longus acts to evert the foot, plantarflex the ankle and adds support to the transverse arch of the foot
- Blood Supply – Anterior tibial artery
- Innervation – Superficial peroneal nerve
Peroneus Brevis
- Origin – The peroneus brevis originates on the inferior two-thirds of the lateral fibula and courses posteriorly to the lateral malleolus of the fibula ultimately
- Insertion – The styloid process of the fifth metatarsal
- Action – The primary action of the peroneus brevis is to evert the foot and plantarflex the ankle
- Blood Supply – Peroneal artery
- Innervation – The superficial peroneal nerve innervates the peroneus brevis muscle
Peroneus Tertius
- Origin – The peroneus Tertius originates from the middle fibular shaft
- Insertion – The dorsal surface of the fifth metatarsal
- Action – Dorsiflex, evert, and abduct the foot
- Blood Supply – The peroneus Tertius primarily receives its blood supply from the anterior tibial artery
- Innervation – Peroneus Tertius innervation comes from the deep peroneal nerve, and innervation different than its similarly named peroneal counterparts
Pathophysiology
The trimalleolar groove has different shapes; a cadaveric study showed out of 178 ankles the groove is concave in 82%, flat in 11 %, and convex in 7% with a non-osseous fibrocartilaginous ridge that is on the medial side of the groove.[rx]
Peroneal Tendonitis
- Lateral ankle instability can cause laxity, leading to the increased motion of the tendons around the fibula with stretched superior peroneal retinaculum
Peroneal Subluxation/Dislocation
- Instability can be acute from the rupture of the superior retinaculum or fibular groove avulsion or chronic. Chronic subluxation is associated with fibular groove flattening laxity of the superior retinacular ligament.[rx]
Peroneal tendon tear
- Musculotendinous junction during forceful contraction or in the cuboid tunnel
- Most tears are longitudinal and result from chronic subluxation over the distal fibula.[rx]
Causes Of Peroneal Tendon Disorders
There have been numerous traumatic and atraumatic causes of peroneal nerve injury. Common causes of damage to the peroneal nerve include the following[3][4][5]:
- Anatomic risk factors
- Common peroneal nerve entrapment can occur secondary to a fibrous band at the origin of the peroneus longus
- External compression sources
- Tight splint/cast
- Compression wrapping/bandage
- Habitual leg crossing
- Prolonged bed rest
- Can be seen in comatose patients or those intubated for prolonged periods
- Positioning during anesthesia/surgery
- Important to always pad bony prominences, including the area of the fibular head/neck at the lateral aspect of the knee
- Intraneural ganglion
- Peripheral nerve tumor
- Iatrogenic injury following surgery about the hip, knee, and ankle
The common peroneal nerve is most vulnerable to injury as it passes around the fibular neck. Therefore it is most susceptible to injury at the lateral aspect of the knee.[]rx[rx]
Several systemic illnesses can cause compressive peroneal pain, numbness, tingling, or weakness. সহজ বাংলা: স্নায়ুর ক্ষতি/সমস্যা।" data-rx-term="neuropathy" data-rx-definition="Neuropathy means nerve damage or irritation causing pain, numbness, tingling, or weakness. সহজ বাংলা: স্নায়ুর ক্ষতি/সমস্যা।">neuropathy and injury to the common peroneal nerve, including[rx]:
- insulin is low or not working well. সহজ বাংলা: রক্তে চিনি বেশি থাকার রোগ।" data-rx-term="diabetes" data-rx-definition="Diabetes is a condition where blood sugar stays too high because insulin is low or not working well. সহজ বাংলা: রক্তে চিনি বেশি থাকার রোগ।">Diabetes mellitus
- Inflammatory conditions
- Motor neuron diseases (Charcot-Marie-Tooth disease)
- Anorexia nervosa (exceedingly thin states) due to loss of subcutaneous fat at this level causing compression of the nerve
These are the main causes that can lead to the appearance of a high ankle
- Walking or exercising on an uneven surface
- Falling down
- Participating in sports that require cutting actions or rolling and twisting of the foot—such as trail running, basketball, tennis, football, and soccer
- During sports activities, someone else may step on your foot while you are running, causing your foot to twist or roll to the side.
Rotational injuries
- Ankle fractures
Impact sports
- Football tackles
- Falling or being pushed forward
- Side-to-side running
- Starting and stopping feet in a repetitive manner
- Turning while moving
- Other sports: hockey, wrestling, soccer
Mechanism
- Foot is planted on the ground
- Foot is then twisted outward (excessively)
- Bones pull away from each other and the syndesmotic ligaments that connect them are torn
Increased risk
- Severe load on the ankle
- Excessive dorsiflexion of the foot – toes go beyond their normal range of motion, towards the shin
- When a person is tangled under another person.
Symptoms Of Peroneal Tendon Disorders
In an ankle sprain, the following signs and symptoms may occur
- Weakness, numbness, or tingling in your arms or legs if the bone spur presses on nerves in your spine
- Muscle spasms, cramps, or weakness
- Bumps under your skin, seen mainly in the hands and fingers
- Other symptoms may include: numbness, burning, and pins and needle sensations that may affect the shoulders, arms, hands, buttocks, legs or feet
- Pain that eases with rest and worsens with activity
- Muscle spasms
- Cramping
- Weakness
- Rub against other bone or tissue
- Restrict movement
- Squeeze nearby nerves
- Trouble controlling your bladder or bowels if the bone spur presses on certain nerves in your spine (a symptom that’s seen very rarely)
Diagnosis of Peroneal Tendon Disorders
- X-rays – should be weight-bearing and include standard AP, mortise, and lateral ankle views. Additional X-ray views are the axillary/Harris heel view and AP, lateral and oblique views of the foot to look for other fractures and foot alignment. Findings on the x-ray that indicate peroneal pathology are avulsion from the base of the fifth metatarsal, avulsion fracture of the distal fibular groove, os perineum, and trimalleolar groove flattening.[rx]
- Ultrasound – is a no radiation, inexpensive imaging modality that can provide an evaluation of the tendon in motion, as well as assist with injections. It has been shown to be effective in identifying tears as well with a sensitivity of 100 % and specificity of 85%.[rx]
- MRI – is the next step in evaluation with a high-quality view of the tendons with no exposure to radiation. The sensitivity is 83%, and specificity is 75% for peroneus brevis tears. Findings include fluid surrounding the tendons, discontinuity, edema of the bone, and any bony deformity.[rx]
- CT scanning – does expose the patient to radiation but provides better bony detail to evaluate possible bony deformity causing possible tendon dysfunction. If x-rays indicate the possibility of fracture, peroneal tubercle, or retro trochlear eminence CT scan would be useful and determine possible management.[rx]
Treatment of Peroneal Tendon Disorders
Nonoperative treatment
- Nonsteroidal anti-inflammatory drugs, ice, rest or immobilization, and physical therapy. Immobilization can include cast or controlled ankle motion boot. Modification of shoe wear can also help unload the peroneal tendons with the use of a lateral heel wedge.
- PRP injections with ultrasound guidance have shown improved functional outcomes with tendinopathy in the study by Dallaudiere. Four hundred eight patients showed 23 patients with peroneal tendon disorders.[rx]
Non-operative treatment should be for 4 to 6 months to allow resolution of inflammation
Operative treatment
If conservative treatment has failed, operative management options of each type of disorder are as follows:
Peroneal Tendonitis
- Open Debridement and synovectomy
Peroneal tendon subluxation
Treatment depends on the cause of the subluxation or dislocation. Goals are to restore the fibrocartilaginous rim, the superior peroneal retinaculum, and periosteum to the fibula and obtain smooth gliding of the tendon with adequate space for motion.
- If the superior peroneal retinaculum is torn then open or endoscopic repair or reconstruction is necessary.
- Avulsion fracture of the fifth metatarsal or fibular groove should entail fixation or repair.
- If the fibular groove is shallow endoscopic or open fibular groove deepening can be performed to provide a better structure for the peroneal tendons. This procedure usually addresses cases of chronic instability.
- If there is any hindfoot varus alignment, this should also be corrected to decrease stress on the peroneus longus with hindfoot osteotomy.
- Rerouting the peroneal tendons underneath the calcaneofibular ligament.[rx]
- Bone block procedures that involve performing osteotomy of the fibula lateralizing it to create a bony block for the tendons.[rx]
Peroneal tendon tears
Treatment depends on the degree of tendon torn and whether the tear is acute or chronic
- Debridement and tubularization- partial tears of less than 50%.
- Repair end to end of acute complete tears
- Side-to-side anastomosis or Pulvertaft weave with chronic tears[rx]
- Allograft reconstruction.
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