Q: We are the parents of a 15-year-old boy who started having foot pain last year when he started running with a friend. Turns out he has one bone instead of the usual three bones in his right foot. The treatment choices have been explained to us. What are his chances for recovery without surgery?
A: It sounds like your son may have a condition known as tarsal coalition. Tarsal coalition is the failure of the developing bones in the foot to properly form all the distinct, individual bones. The problem occurs most often in the midfoot (between the ankles and toes). Two or more bones form a bridge of bone between them or they fuse together. Males are affected more often than females though the reason for this remains unknown.
There may be no treatment required for some people with this condition. That's because some children and teens don't develop any symptoms until they are older. Some folks never experience any problems associated with tarsal coalition. But weight gain, an injury, or a sudden increase in activity can result in pain, stiffness, and/or a limp.
Conservative care is the first-line of treatment for bone deformities of this type. This can include orthotics (molded shoe inserts), nonsteroidal antiinflammatory medications, or steroid injections. Changes in activity can also provide some relief from symptoms.
Surgery is another treatment possibility but this is usually reserved for patients with foot pain that is intolerable and doesn't go away otherwise. Usually, the bar of bone is removed and body fat or muscle is used to fill in the space. Packing the space left by bone excision (removal) is necessary so the bone doesn't grow back in.
The prognosis is good for tarsal coalition when it is diagnosed early or when the affected individual is fairly inactive. There is usually a favorable outcome for patients with a foot that is fused in the neutral position. Fusion can occur naturally (be present as part of the condition) or can be done surgically.
The goals of all treatment are to reduce (eliminate if possible) pain and other symptoms, to correct ankle and foot alignment, and to restore full function of the foot and ankle complex. After surgery an orthosis (molded shoe insert) may be prescribed to support the foot and ankle. Results of surgical treatment vary depending on how many bones are affected, the type of surgery done, and whether or not complications occur during or after the procedure.
Good-to-excellent results are reported in 75 per cent of all surgical cases. The remaining 25 per cent may have less optimal results if there is an incomplete correction of the problem. Damage to nerves in the surgical area can result in unexpected problems. Even with a few bumps in the road, most children are back to full play and activities three to six months later.
Reference: Katharine Thomason, and Michael M. Stephens, MSc, FRCSI. Tarsal Coalition. In Current Orthopaedic Practice. May/June 2012. Vol. 23. No. 3. Pp. 229-234.