Anatomy
Lateral compartment of leg
- run through retromalleolar groove
- pass superior and inferior to peroneal tubercle
- covered by inferior peroneal retinaculum
Peroneus longus
- origin lateral condyle of tibia and head fibula
- tendon PL superficial and inferior to brevis in retromalleolar groove
- runs in cuboid groove
- insert plantar surface base of 1st MT and lateral aspect medial cuneiform
- everts the foot / plantar flexes the first ray / plantar flexes the ankle
- stabilises the medial arch in stance
Os peroneum
- sesamoid in PL
- level CCJ / articulates with cuboid
- 20% population
Peroneus brevis
- origin middle third fibula and intermuscular septum
- inserts tuberosity base 5th
- abducts and everts the foot / plantar flexes the ankle
Nerve supply
- SPN
Definitions
Tendonitis
- inflammation of tenosynovium
Tendonosis
- degenerative change in tendon
- can lead to tears
Aetiology
Tendonitis
Prolonged or repetitive activity
- usually after period activity
- runners and ballets dancers
Cavovarus hind foot
Tears
- acute injury
- chronic tendonitis
- dislocation / subluxation
Associations
Chronic lateral ankle instability
Peroneal tendon subluxation
Cavovarus hindfoot
Peroneal Tendon Tears
Incidence
P. brevis torn more frequently than longus
Classification
Sobel & Mizel 1993
Zone 1
- behind lateral malleolus
- brevis more commonly injured
Zone 2
- distal to tip of fibula
- longus only
- cuboid tunnel acts as a fulcrum
- can get inflammation & swelling
- loss of excursion as brevis & longus skirt around pulley
History
Acute or chronic lateral ankle pain
Examination
Tenderness / swelling along tendons
Pain
- passive inversion and PF
- active eversion
DDx
Lateral instability
Fracture fibula / 5th MT / cuboid / Calcaneal
OCD talus
Loose body ankle
OA ankle
Sinus tarsi syndrome
Tarsal coalition
MRI
10 tendons about ankle
- axial views most usefull
- T1 displays anatomy
- T2 STIR shows tears
- beware magic angle (fibres orientated 55 degrees to scan)
Findings
- tendon thickening / tendonopathy
- fluid about tendons / tendonitis
- tears
Management
Non Operative
NSAIDS
Modification activities
Lateral heel wedge if hindfoot varus
Moon boot / SL walking cast
Operative
1. Tenosynovitis
Open debridement and tenosynovectomy
- incision posterior to fibula and to base 5th MT
- sural nerve halfway between peroneals and T Achilles
- open peroneal tendon sheath
- debride synovitis
Must also treat any
- inflamed os peroneum
- varus heel
- tears
2. Tears
A. <50%
- excise & repair tears by tubularisation
- incision 1 cm posterior to fibular
- from 5 cm above to base of 5th metatarsal
- immobilise with foot PF and everted to rest in POP
- after 2 weeks in moonboot for progressive mobilisation
B. > 50%
One tendon torn
- tenodesis to other tendon
Both tendons torn
1. 2 stage reconstruction
2. Tendon transfer FDL to PB / plantaris to PL