Accessory Ossicle Navicular Pain

Overview
Accessory navicular syndrome occurs when a type II accessory navicular (or "os tibiale externum") becomes painful due to movement across the pseudojoint between the ossicle and the navicular bone. The syndrome presents on MRI with bone marrow oedema signal (hypointense T1, hyperintense T2/STIR) in both the accessory ossicle and navicular. It can be inferred on musculoskeletal ultrasound if a patient's pain is located at a type II accessory navicular and the patient is tender to transducer pressure. Ultrasound can also be useful to compare with the contralateral side.



Causes
This can result from any of the following. Trauma, as in a foot or ankle sprain. Chronic irritation from shoes or other footwear rubbing against the extra bone. Excessive activity or overuse. Many people with accessory navicular syndrome also have flat feet (fallen arches). Having a flat foot puts more strain on the posterior tibial tendon, which can produce inflammation or irritation of the accessory navicular.

Symptoms
What are the signs/symptoms of Accessory Navicular Syndrome? Pain in the foot following trauma (such as after an ankle sprain) Chronic irritation from shoes or other footwear rubbing against the bone. A visible bony prominence on the inner side of the foot just above the arch. Redness and swelling of that area. Vague pain or throbbing in the arch mostly occuring during or after periods of physical activity. Symptoms appear most often during adolescence, but some may not occur until adulthood.

Diagnosis
To diagnose accessory navicular syndrome, medical staff ask about the patient?s activities and symptoms. They will examine the foot for irritation or swelling. Medical staff evaluate the bone structure, muscle, joint motion, and the patient?s gait. X-rays can usually confirm the diagnosis. MRI or other imaging tests may be used to determine any irritation or damage to soft-tissue structures such as tendons or ligaments. Because navicular accessory bone irritation can lead to bunions, heel spurs and plantar fasciitis, it?s important to seek treatment.

Non Surgical Treatment
Using PRP treatments, orthotics, proper running shoes and physical therapy should do the trick. No long recovery, no long down time. My runners and athletes are usually back to their sport pain free within a month. The key is eliminating the syndrome, not the bone (or cartilage).



Surgical Treatment
If non-operative treatment fails to relieve the patient’s symptoms, surgical intervention may be warranted. The standard operative treatment of an accessory navicular is a Kidner procedure. However, if surgery is undertaken it is important that it address the underlying source of the patients pain.