Peroneal Tendon Dislocation
synonyms: peroneal tendon instability
Peroneal Tendon Instability ICD-9
- Peroneal tendinitis ICD-9 = 726.79
Peroneal Tendon Instability Etiology / Epidemiology / Natural History
- often accompanied by avulsion of the posterior osteochondral ridge of the distal fibula seen on plain xray
- mechanism of injury (acute dorsiflexion and violent reflex peroneal musculature contraction) precipitates an avulsion of the superior peroneal retinaculum, allowing dislocation ot the peroneal tendons anteriorly.
- Common in soccer and skiing.
Peroneal Tendon Instability Anatomy
- Superior peroneal retinaculum: primary retaining structure for the perneal tendons. Origin: posterior margin of the distal 1-2cm of the fibula. Travels posteriorly to blend with the Achilles tendon sheath. (Maffuli N, AJSM 2006;34:986).
- Deficient posterior distal fibular groove may contibute to peroneal instability.
- see also Ankle Anatomy.
Peroneal Tendon Instability Clinical Evaluation
- Lateral ankle pain, swelling and ecchymosis.
- Tenderness posterioly along the peroneal tendons.
- Pain and weakness with active ankle dorsiflexion and external rotation.
- Lateral tenderness, no medial tenderness.
- May complain of popping in the posterolateral ankle with push off.
- Ankle Circumduction Test:
Peroneal Tendon Instability Xray / Diagnositc Tests
- A/P, Lateral and Mortise views of the ankle are generally normal. May demonstrate a "fleck" sign: small avulsion fracture of the lateral malleolus which is pathognomonic for acute dislocation of the peroneal tendons and indicates Grade III injury to the superior peroneal retinaculum.
- MRI: demonstrates peroneus brevis +/- peroneus longes dislocated anterolateral to the lateral malleolus with disruption of the peroneal retinaculum.
- Dynamic ultrasound: may be indicated to evaluated for pseudosubluxation of the peroneal tendons.
Peroneal Tendon Instability Classification / Treatment
- Surgical exploration with reduction of tendons and repair of superior peroneal retinaculum +/- deepening of the retromalleolar groove.
- Pseudosubluxaiton: no subluxation for the retrofibular groove with dorsiflexion-eversion maneuver but with painful snapping symptoms related to the peroneus longus snapping through or over the peroneus brevis. Treatment = repair of tendon tears with peroneal groove deepening. (Raikin SM)
- Poor outcome with non-op treatment. Consider bracing or taping for in season athletes with definitive surgical treatment after season ends.
- Patient Guides: eOrthopod, eOrthopod subluxation,
Peroneal Tendon Instability Associated Injuries / Differential Diagnosis
Peroneal Tendon Instability Complications
- Recurrent instability
- Continued pain
Peroneal Tendon Instability Follow-up Care
Peroneal Tendon Instability Review References
- Philbin TM, JAAOS 2009;17:306
- Murr S: Dislocation of the peroneal tendon with marginal fracture of the lateral malleolus. J Bone Joint Surg 1965;43B:563-565.
- Eckert WR, Davis EA Jr: Acute rupture of the peroneal retinaculum. J Bone Joint Surg 1976;58A:670-672.
- Zoellner G, JBJS 1979;61A:292