be displayed on MRI examination. Dislocation of the peroneal tendons can occur when there is rupture of the per- oneal retinaculum (Fig.3).
The tendons
may remain in their dislocated position or spontaneously relocate and only dislocate under strain. Some patients can manage adequately without further intervention but if symptoms persist then surgical repair needs to be considered.
8. IMPINGEMENT SYNDROMES i) Antero-lateral impingement This may occur following inversion injury from a single episode or recurrent minor injuries.
A thickening occurs within the
antero-lateral recess of the ankle joint which becomes a palpable tender lesion. There are two theories to the development of this. Firstly that it is a traumatic syn- ovial thickening which becomes hyalin- ized secondary to pressure.
Secondly,
that it occurs as a result of a fragment of a torn anterior tibio-fibular ligament becoming interposed between the talus and the lateral malleolus.
Arthroscopy
reveals a meniscoid-type lesion which is resected. help.
Cortico-steroid injection may
ii) Anterior impingement Cause: Anterior impingement may occur secondary to osteophytes on the neck of the talus or the anterior tibia produced by dorsiflexion impinging and trapping the synovium which becomes chronically thickened.
These lesions are sometimes
seen after repeated ankle inversion injuries and are seen frequently in dancers and American footballers.
Alternatively a
(c) multiple abnormal fluid collections consistent with synovial cysts
Management: Injection of anaesthetic and cortico-steroid is an extremely effec- tive and rewarding therapeutic treatment but the correct injection placement is essential. The sinus tarsi opening is pal- pated and using a blue 21 gauge needle, the needle is inserted at a 45o angle along the tarsal canal until it is completely inserted. Injection of the steroid/anaes- thetic mixture is then made and the nee- dle is retracted along the canal. Following injection, activity is limited for 7-10 days and then peroneal strengthen- ing and proprioceptive exercises can be resumed. Sports specific activity can usu- ally be resumed within three weeks.
In
the author’s series of 20 patients with an average time to presentation in excess of 15 months, it took an average of two weeks to become pain free. Taping or orthotic insertion should be considered if there is excessive pronation which would increase the sheer force in the subtalar joint.
7. PERONEAL TENDON INJURY
Close association of the per- oneal tendon sheath and the CFL may result in tearing of the ten- don sheath or tendons them- selves following a severe inver- sion injury.
These lesions will traction lesion may occur on the anterior Figure 4: Posterior view of the bones of the ankle and foot