Overview
An accessory navicular bone is an accessory bone of the foot that occasionally develops abnormally causing a plantar medial enlargement of the navicular. The accssory navicular bone presents as a sesamoid in the posterior tibial tendon, in articulation with the navicular or as an enlargment of the navicular. Navicular (boat shaped) is an intermediate tarsal bone on the medial side of the foot. It is located on the medial side of the foot, and articulates proximally with the talus. Distally it articulates with the three cuneiform bones. In some cases it articulates laterally with the cuboid. The tibialis posterior inserts to the os naviculare. The tibialis posterior muscle also contracts to produce inversion of the foot and assists in the plantar flexion of the foot at the ankle. Tibialis posterior also has a major role in supporting the medial arch of the foot. This supports is compromised by abnormal insertion of the tendon into the accessory navicular bone when present. This lead to loss of suspension of tibialis posterior tendon and may cause peroneal spastic pes planus or simple pes planus. But, yet a cause and effect relationship between the accessory navicular and pes planus is doubtful and is yet unproved clearly.
Causes
This painful foot condition is caused by an extra bone in the foot called the accessory navicular. Only about 10% of people have this bone (4 to 21%), and not all of them will develop any symptoms. The navicular bone is one of the normal tarsal bones of the foot. It is located on the inside of the foot, at the arch.
Symptoms
Adolescence is a common time for the symptoms to first appear. This is a time when bones are maturing and cartilage is developing into bone. Sometimes, however, the symptoms What do eccentric heel drops do? not occur until adulthood. The signs and symptoms of accessory navicular syndrome include a visible bony prominence on the midfoot (the inner side of the foot, just above the arch) Redness and swelling of the bony prominence, Vague pain or throbbing in the midfoot and arch, usually occurring during or after periods of activity.
Diagnosis
Diagnosis is fairly simple based on an examination by your doctor. He or she will palpate the navicular bone, and based on the location of pain will suspect an accessory navicular. The doctor will also observe your gait to see if you are flatfooted. At this point an x-ray will make the definitive diagnosis. Other causes of pain in the same area of the foot would include a fracture of the navicular bone or possibly tendonitis or even a partial tear of the tibialis posterior tendon that inserts into the navicular. In these cases there is usually a history of trauma. People with a naturally "large" navicular bone may also develop a bursitis due to chronic shoe pressure.
Non Surgical Treatment
Initial treatment is conservative. With the first episode of symptoms, a medial heel wedge, anti-inflammatories, and physical therapy can be helpful. If very painful, a cast or boot may be needed for a short period time before the wedge and physical therapy can be initiated. Very rarely is a steroid injection warranted or recommended. As the pain improves, patients can resume activities. For a minority of patients, an arch support or custom orthotic can help to take some of the extra pressure off of the accessory navicular and the posterior tibial tendon.
Surgical Treatment
Once the navicular inflammation has lessened it is not necessary to perform surgery unless the foot becomes progressively flatter or continues to be painful. For these children, surgery can completely correct the problem by removing the accessory navicular bone and tightening up the posterior tibial tendon that attaches to the navicular bone. The strength of this tendon is integral to the success of this surgery as well as the arch of the foot. Following surgery the child is able to begin walking on the foot (in a cast) at approximately two weeks. The cast is worn for an additional four weeks. A small soft ankle support brace is then put into the shoe and worn with activities and exercise for a further two months.
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An accessory navicular bone is an accessory bone of the foot that occasionally develops abnormally causing a plantar medial enlargement of the navicular. The accssory navicular bone presents as a sesamoid in the posterior tibial tendon, in articulation with the navicular or as an enlargment of the navicular. Navicular (boat shaped) is an intermediate tarsal bone on the medial side of the foot. It is located on the medial side of the foot, and articulates proximally with the talus. Distally it articulates with the three cuneiform bones. In some cases it articulates laterally with the cuboid. The tibialis posterior inserts to the os naviculare. The tibialis posterior muscle also contracts to produce inversion of the foot and assists in the plantar flexion of the foot at the ankle. Tibialis posterior also has a major role in supporting the medial arch of the foot. This supports is compromised by abnormal insertion of the tendon into the accessory navicular bone when present. This lead to loss of suspension of tibialis posterior tendon and may cause peroneal spastic pes planus or simple pes planus. But, yet a cause and effect relationship between the accessory navicular and pes planus is doubtful and is yet unproved clearly.
Causes
This painful foot condition is caused by an extra bone in the foot called the accessory navicular. Only about 10% of people have this bone (4 to 21%), and not all of them will develop any symptoms. The navicular bone is one of the normal tarsal bones of the foot. It is located on the inside of the foot, at the arch.
Symptoms
Adolescence is a common time for the symptoms to first appear. This is a time when bones are maturing and cartilage is developing into bone. Sometimes, however, the symptoms What do eccentric heel drops do? not occur until adulthood. The signs and symptoms of accessory navicular syndrome include a visible bony prominence on the midfoot (the inner side of the foot, just above the arch) Redness and swelling of the bony prominence, Vague pain or throbbing in the midfoot and arch, usually occurring during or after periods of activity.
Diagnosis
Diagnosis is fairly simple based on an examination by your doctor. He or she will palpate the navicular bone, and based on the location of pain will suspect an accessory navicular. The doctor will also observe your gait to see if you are flatfooted. At this point an x-ray will make the definitive diagnosis. Other causes of pain in the same area of the foot would include a fracture of the navicular bone or possibly tendonitis or even a partial tear of the tibialis posterior tendon that inserts into the navicular. In these cases there is usually a history of trauma. People with a naturally "large" navicular bone may also develop a bursitis due to chronic shoe pressure.
Non Surgical Treatment
Initial treatment is conservative. With the first episode of symptoms, a medial heel wedge, anti-inflammatories, and physical therapy can be helpful. If very painful, a cast or boot may be needed for a short period time before the wedge and physical therapy can be initiated. Very rarely is a steroid injection warranted or recommended. As the pain improves, patients can resume activities. For a minority of patients, an arch support or custom orthotic can help to take some of the extra pressure off of the accessory navicular and the posterior tibial tendon.
Surgical Treatment
Once the navicular inflammation has lessened it is not necessary to perform surgery unless the foot becomes progressively flatter or continues to be painful. For these children, surgery can completely correct the problem by removing the accessory navicular bone and tightening up the posterior tibial tendon that attaches to the navicular bone. The strength of this tendon is integral to the success of this surgery as well as the arch of the foot. Following surgery the child is able to begin walking on the foot (in a cast) at approximately two weeks. The cast is worn for an additional four weeks. A small soft ankle support brace is then put into the shoe and worn with activities and exercise for a further two months.
Th1s1sanart1cl3s1te