Os Peroneum and Os Peroneum Syndrome
The os peroneum is found within the peroneus longus in 20% of feet. They are usually located plantar to the cuboid, lateral to the calcaneus, or at the calcaneocuboid joint.[1] It is a factor in the development of peroneus longus stenosing tenosynovitis.[2]
Pathophysiology
Individuals with an os peroneum, especially those with hypertrophy of the peroneal tubercle, are predisposed to developing peroneus longus stenosing tenosynovitis in the cuboid tunnel.
Clinical Features
Patients complain of lateral ankle and/or foot pain.
Physical exam shows tenderness over the lateral plantar cuboid or at the calcaneocuboid joint. There may be thickening and tenderness of the peroneus longus tendons and peroneus brevis tendon sheath. Pain is exacerbated with the heel-rise phase of gait. Pain is also exacerbated by resisted plantarflexion of the first ray (first metatarsal and two phalanges of the great toe). The varus inversion stress test may provoke pain and this is performed by putting the foot in an inverted, supinated, and adducted position. Forced foot eversion may also cause pain.[1]
Investigations
Standard plain films show the Os peroneum (AP, lateral, mortise of the ankle, and AP and oblique of the foot). Also look for fracture, diastasis of multipartite Os peroneum, callus formation, proximal migration of the Os peroneum.[1]
Treatment
First line treatments are rest, ice, and NSAIDs.
In severe cases immobilisation of the limb may be required.
The patient should also have a graded exercise programme.
References
- ↑ 1.0 1.1 1.2 Sobel M, Pavlov H, Geppert MJ, Thompson FM, DiCarlo EF, Davis WH. Painful os peroneum syndrome: a spectrum of conditions responsible for plantar lateral foot pain. Foot Ankle Int. 1994 Mar;15(3):112-24. doi: 10.1177/107110079401500306. PMID: 7951939.
- ↑ Clarke HD, Kitaoka HB, Ehman RL. Peroneal tendon injuries. Foot Ankle Int. 1998 May;19(5):280-8. doi: 10.1177/107110079801900503. PMID: 9622417.
