Tendonitis / Tendonopathy

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

 

Os Peronei

 

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

 

Peroneal Tendon Swelling

 

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

 

Peroneal TendonitisPeroneal Tendonitis MRIPeroneal Tendonitis MRI 2

 

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

 

Peroneals Intra-operatively

 

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