You are here

Accessory Tarsal Navicular


synonyms:Accessory Navicular, accessory tarsal navicular, accessory scaphoid, os tibiale, os tibiale externum, prehallux, os naviculare secundarium, and navicular secundum

Accessory Navicular ICD-9

  • Consider 732.5  Juvenile osteochondrosis of foot Calcaneal apophysitis Epiphysitis, os calcis Osteochondrosis (juvenile) of: astragalus (of Diaz) calcaneum (of Sever) foot NOS metatarsal: second (of Freilberg) fifth (of Iselin) os tibiale externum (of Haglund) tarsal navicular (of Köhler)

Accessory Navicular Etiology / Epidemiology / Natural History

  • normal variant seen in up to 12% of population (Coskun, N, Surg Radiol Anat 2009;31:19
  • associated with flat feet (pes planovalgus)
  • medial arch pain with overuse

Accessory Navicular Anatomy

  • Accessory navicular is on the medial aspect of the arch, posterior and medial to the tuberosity of the tarsal navicular.
  • Accessory navicular bones have variable attachements with the insertional fibers of the posterior tibial tendon.

Accessory Navicular Clinical Evaluation

  • Erythema, tenderness overlying the navicular tuberosity.

Accessory Navicular Xray / Diagnositc Tests

  • A/P, lateral and obliqueviews of the foot. Often only seen on the external oblique xray.
  • Bone scan can be helpful in unclear cases or patients with bilateral accessory naviculars

Accessory Navicular Classification / Treatment

  • Type I: sesamoid contained within the posterior tibial tendon, 30%.  Rarely symptomatic
  • Type II: most commonly symptomatic; 8-12mm ossicle seperated from the normal navicular.  Separated into 2 types based on the angle of attachment to the navicular. IIa connects with the talar process by a less acute angle:risk for avulsion injury. IIb connects at an acute angle; susceptible to shearing forces.
  • Type III: ossicle united to the navicular by a bony bridge forming a prominent navicular tuberosity. Rarely symptomatic.
  • non-op semi-rigid orthosis with a medial arch support (Bennett J Pediatr Orthop 10:445;1990), activity modifications, shoe modifications to avoid pressure over prominent navicular, NSAIDS, most symptoms resolve spontaneously, short period of cast immobilization if severe.
  • Surgical excision indicated if fails non-op treatment. Consider fixation for patients with very large accessory naviculars.
  • Percutaneous Drilling of symptomatic accessory navicular has demonstrated good results in young athletes. (Nakayma S, AJMS 2005;33:531)
  • Percutaneous drilling technique:
    -general anesthesia  or local
    -1.0mm Kirschner wire introduced percutaneously from the posterior part of the prominence on the accessory navicular
    to the primary navicular through synchondrosis at 5 to 7 different points under radiographic fluoroscopic
    -foot immobilized below-the-knee cast with moderate equinovarus position for 3 weeks.

Accessory Navicular Associated Injuries / Differential Diagnosis

Accessory Navicular Complications

Accessory Navicular Follow-up Care

  • Full weightbearing 2 weeks post-op. 
  • 4 weeks: cast removed, active exercise started
  • 6 weeks: light jogging allowed
  • 8 weeks: gradually return to sport specific exercise
  • 10 weeks: full activity if painfree

Accessory Navicular Review References

  •  Zachary C, Foot and Ankle Clinics, 2010;15:337-347
  • °


The information on this website is intended for orthopaedic surgeons.  It is not intended for the general public. The information on this website may not be complete or accurate.  The eORIF website is not an authoritative reference for orthopaedic surgery or medicine and does not represent the "standard of care".  While the information on this site is about health care issues and sports medicine, it is not medical advice. People seeking specific medical advice or assistance should contact a board certified physician.  See Site Terms / Full Disclaimer