It is generally understood that the surgical excision of a tarsal coalition will restore motion to the rearfoot and a painful tarsal coalition is an indication to do surgery.
However, what does it really mean to “restore motion”? Once this motion is restored, does this once rigid foot now function as a flexible foot?
A rigid flatfoot due to tarsal coalition is not a “normal” functioning foot and one should not consider it as such. While a patient may have a tarsal coalition without structural deformity (i.e., a well aligned foot) and the absence of pain, the back part of the foot is rigid and does not move. This is not “normal” mechanics of the foot. While other secondary compensations may occur from adjacent joints as adapted measures over time that have enabled the lower extremity to function as a “normal” segment, the rearfoot biomechanics are simply altered with tarsal coalition.
In theory, removing a tarsal coalition (removing the cause for restricted motion) should allow for the return of motion and allow the foot to function as normal. But does the foot ipso facto become a flexible foot?
Resection of the coalition allows for rearfoot motion but this motion will never be to the extent of that of a native joint. Scar tissue forms at the resection site so one can expect some degree of decreased motion and not “full” motion. It is the return of any motion that is important in these cases.
An extra-articular coalition (calcaneonavicular) is more likely to regain more motion than that of an intra-articular coalition (middle facet tarsal coalition). Obviously, a coalition external to a joint will be more amenable to achieving motion after a resection. Younger patients are more likely to achieve more motion after simple resection as well.
In my experience, patients regain motion after resection but the surgeon should expect some overall stiffness to the rearfoot despite removing the blockade to motion.
Future studies that investigate the extent of motion “regained” after resection would be valuable.
Dr. Blitz is the Chief of Foot Surgery & Associate Chairman of Orthopaedics at Bronx-Lebanon Hospital Center in Bronx, N.Y. Dr. Blitz can be reached at email@example.com .
1. Kernbach KJ, Blitz NM, Rush SM. Bilateral single-stage middle facet talocalcaneal coalition resection combined with flatfoot reconstruction: a report of 3 cases and review of the literature. Investigations involving middle facet coalitions--part 1. J Foot Ankle Surg. 2008;47(3):180-90.
2. Blitz NM. Pediatric and adolescent flatfoot reconstruction in combination with middle facet talocalcaneal coalition resection. Clin Podiatr Med Surg. 2010; 27(1):119-33.
3. Kernbach KJ, Blitz NM. The presence of calcaneal fibular remodeling associated with middle facet talocalcaneal coalition: a retrospective CT review of 35 feet. Investigations involving middle facet coalitions--Part II. J Foot Ankle Surg. 2008; 47(4):288-94.
4. Kernbach KJ, Barkan H, Blitz NM. A critical evaluation of subtalar joint arthrosis associated with middle facet talocalcaneal coalition in 21 surgically managed patients: a retrospective computed tomography review. Investigations involving middle facet coalitions-part III. Clin Podiatr Med Surg. 2010; 27(1):135-43.