Peroneal Tendon Subluxation

Tendons are strong white bands of fibrous tissue that connect muscles to bones. As a muscle contracts, it pulls the tendon, which in turn pulls the bone to which it is attached and this carries out the movement of the skeleton.

Tendon subluxation refers to a condition in which the tendon slips out of its normal position during movement; however, it relocates itself back to its normal position. When the tendon fails to relocate itself to its normal position the condition is called tendon dislocation or subluxation.

The peroneal tendons belong to the two peroneal muscles located on the outer side of the lower leg. The two tendons travel downward along the outer side of the ankle, passing behind the outer bump of the ankle. From here the tendons angle forward and pass under the foot where they attach to the lower surface of the bones of the midfoot (metatarsals). As the muscles contract, the tendons pull the foot downward (plantarflexion) and outward (eversion).

Diagram of the foot from the side, showing the tendons and other parts

This curved course of the tendons is secured by the following anatomical structures:

- A sheath surrounds the ligaments as they pass behind the outer bump of the ankle, this sheath is further stabilized by ligaments located both deep (calcaneofibular ligament) and superficial (retinaculum) to it.
- In more than 80% of individuals, there is a groove located on the back of the leg bone to accommodate these tendons
- A bony ridge may further assist the groove in keeping the tendons in place and preventing their subluxation.
Diagram of the foot showing the difference between the tendons in normal position and in subluxation

Causes of peroneal tendon subluxation:

Damage to the retinaculum:

This most commonly occurs after an inversion ankle sprain. As the foot twists inwards, the peroneal tendons are stretched forcefully and their pulley-like action can tear the retinaculum fibers. The damaged retinaculum fails to hold the tendons in place, leading to their subluxation.

Moreover, as the foot rolls inwards, other ligaments located on the outer side of ankle also become damaged. The peroneal tendons have to take on their role as well in stabilizing the ankle. This excessive workload may also cause inflammation of the peroneal tendons called peroneal tendonitis and make them more liable to subluxation.

Dagram of the foot with the ankle extended and the foot and toes pointed

Recurrent ankle sprains may cause instability of the ankle with subsequent peroneal tendon subluxation.

A shallow groove or a small or absent bony ridge may also be the reason behind peroneal tendon subluxation, especially when there is no previous history of ankle sprain.

Location of pain caused by  peroneal tendon subluxation

Foot, seen from the side, during plantarflexion

Symptoms:

  • There is a painful snapping sensation on the outer side of the ankle, as the tendons move out of their place during ankle movement
  • The area is tender
  • Pain while walking on toes or with sideways cutting while running
  • After acute injury, there may also be swelling along with pain in the area

Treatment

Non-Surgical Treatment involves:

Immobilizing the ankle, making sure that the tendons are relocated to their normal position. The immobilization cast is applied for about six weeks.

Diagram of a foot with peroneal tendon subluxation

Surgical Treatment is required in about 50% of cases and it includes the following options:

- Repairing the damaged retinaculum
- Deepening the groove
- Creating a bone block by cutting and reattaching the bone near the lower end of fibula

Orthotics that will help to treat a Peroneal Tendon Subluxation can be found below.




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THE KEY STEPS TO GETTING THE RIGHT SIZE DOCPODS:

FULL LENGTH INSOLES 

NON FULL LENGTH INSOLES 

1. Measure your existing shoe insole:

 1. Measure from your heel to ball of foot:


 

2. Then compare your measurements from above to match the product size charts below:
(you can trim to fit the insoles by approximately 1cm)


Docpods Regular Size Guide - for Slimline, 3 Quarter, Sports


  US UK EURO SLIMLINE 3 QUARTER  SPORTS 
Size  cm cm cm
Small  4-7  4-8  3-6.5  4-7.5  35-40 16  16.3  25.8
Medium  7-9   8-10  6-9  7-10  39-43  17.4 17.2  27.4
Large   9-13  10-14  8-12  9-13  42-47 19.3   18.2 29.4

Docpods Ultra Size Guide - for Ultra Soft

  XXS XS S M L XL
EURO  34  35.5-37.5  38-40  40.5-42  42.5-44  44.5-46.5
UK  2.5  3-4.5  5-6.5  7-8  8.5-9.5  10-12
US MENS  4-5  5.5-6  6.5-7.5  8-9  9.5-10.5  11-13.5
US WOMENS  3.5-5  5.5-7  7.5-9  9.5-10.5  11-12  13-14
LENGTH (cm) 23.2cm 24.9cm 26.2cm 28.8cm 30cm  31.2cm

Docpods Kids Size Guide - for Docpods Kids Fit only

  Size SPORTS  SLIMLINE
XXS 12-1  19.5cm 13cm 
XS 2-3 22.4cm  15.3cm 

Docpods Foot Pillow - Trim to Fit

  S L
US MENS  4.5 - 9  9 - 13
US WOMENS  6 - 10  10 - 14
LENGTH (cm) 26.5cm 29.2cm