Acute peroneal tendon tears present as a relatively sudden onset of lateral ankle or hindfoot pain, frequently in conjunction with a traumatic episode or injury. Underlying or causative factors, including recurrent ankle sprains, hindfoot varus leading to ankle instability, or dislocating peroneal tendons may be associated and can often lead to peroneal tendon tears being overlooked as a cause of persistent lateral ankle or foot pain. Some apparently acute peroneal tendon tears may represent an acute manifestation of an underlying chronic or subclinical abnormality. The spectrum of peroneal tendinopathies includes tenosynovitis, tendinosis, subluxation or dislocation, stenosing tenosynovitis, disorders of the os peroneum, and conditions related to accessory peroneal tendons, as well as acute and chronic tendon tears. These abnormalities of the peroneal tendons may coexist, and one may lead to another, as evidenced by the significant incidence of tears in the presence of dislocating peronei and ankle instability. Suspicion of the possibility of peroneal tendon injury, coupled with careful clinical examination and appropriate investigation, allows the clinician to identify the extent of damage and to implement a successful management plan. Because peroneal tears signify a mechanical abnormality, this management often entails surgical intervention.
Rupture of the tendons of both peroneus longus and peroneus brevis results in considerable disability. We have performed transfer of flexor digitorum longus (FDL) to peroneus brevis in two patients with lateral instability of the hindfoot due to chronic transverse tears of both tendons for which end-to-end repair was not possible. Both patients had excellent function when reviewed after eight and six years, respectively, with no symptoms. CT showed a normal appearance of the FDL in both patients, but the peroneal muscles looked abnormal. Transfer of the FDL provides a reliable solution to lateral instability of the hindfoot resulting from loss of function of both peronei.
