Peroneus Longus Tears Associated with Pathology of The Os Peroneum

Abstract

The peroneal tendons have a range of different types of pathology. The peroneus longus tendon is less commonly involved compared to the peroneus brevis. The os peroneum is a unique accessory bone within the substance of the peroneus longus tendon, which can contribute to this pathology. Fracture, enlargement, degeneration, or entrapment of the os peroneum at the level of the cuboid tunnel or peroneal tubercle can cause functional impairment or tear of the peroneus longus tendon (Sobel et al., Foot Ankle 15(3):112–124, 1994; Stockton and Brodsky, FAI 35(4):346–352, 2014). Clinically, patients can develop plantar-lateral hindfoot pain and functional weakness. The diagnosis is usually clinically obvious based on tenderness at the cuboid tunnel or tubercle and pain with isolated testing of the peroneus longus against resistance. The diagnosis can be supported with plain radiographs, MRI, or CT scans. Conservative treatment varies depending on the severity and duration of the symptoms. Immobilization with casting or bracing, orthotics, NSAIDs, and physical therapy can be successful. Chronic cases tend to fare worse and often eventually need surgical intervention. Acute cases treated conservatively tend to have better results (Sobel et al., Foot Ankle 15(3):112–124, 1994; Sammarco, FAI 16(5):245–253, 1995). Surgical management options include excision of the os peroneum with either primary repair or longus to brevis tenodesis, assuming the brevis is salvageable. Open reduction internal fixation of a fractured os peroneum has also been described (Peacock et al., CORR 202:223–226, 1986). Surgical management tends to be successful in the majority of cases.