The Painful Accessory Navicular: A Clinical and Histopathological Study

Abstract

Twenty-two skeletally immature patients with 39 accessory tarsal navicular bones were seen over a 4-yr period. Twenty-five of the feet with accessory naviculars were symptomatic and, after failure of conservative treatment, were treated by excision of the accessory bone, the synchondrosis, and the prominent portion of the main navicular ossification process. No attempt was made to reroute the posterior tibial tendon. All 25 operative feet were completely relieved of the preoperative pain. The external oblique view was found to be the best radiographic view to demonstrate the accessory navicular. Histological findings in the surgical specimens included areas of micro-fracture through the cartilaginous synchondrosis, acute and chronic inflammation, and cellular proliferation indicative of attempted repair. These changes are consistent with the theory that chronic chondro-osseous tensile failure can occur in this condition and is responsible for the clinical findings.

Clinical Meaning of Hot Uptake on Bone Scan in Symptomatic Accessory Navicular Bones

“…A chronic stress reaction has been suggested based on pathologic reports about micro-fractures, new bone formation and inflammation, and cellular proliferation through the cartilaginous synchondrosis [9]. There is also osteonecrosis, which creates bone marrow edema on magnetic resonance imaging [3].…”

The foot in sport.

“…One theory is that the pain arises from microtrauma to the cartilage between the accessory bone and the navicular. 20 Others think the cause is direct pressure on the prominent bone. Mild cases may be treated with a medial heel posting orthotic, moderate cases may be treated by casting for six weeks, but more persistent pain may require excision of those accessory navicular bones that are large and separated from the navicular by a cartilage layer ("Type II").…”

Ayak Bileği Burkulması Sonrası Naviküler Kırığı Taklit Eden Aksesuar Naviküler Kemik

“…Hastalar genellikle ayak medial kısmında egzersiz sonrası kötüleşen tekrarlayıcı ağrılardan şikayet eder (6). Tip 2 ANK, bir ayak bileği burkulması sonrası navikü-ler kemiğin kopma kırığı ile karıştırılabilir (1,8,9).…”