Revision tarsal coalition surgery is indeed more complex than primary tarsal coalition surgery. When simple resection has failed, there needs to be more diagnostic effort to identify the cause of recurrent pain. There is a general thought that the coalition itself is the cause of pain. However, it is the secondary effects that the coalition has on the foot that result in the pain cascade. This becomes evident when simple resection does not resolve the patient’s symptoms, warranting the first surgery.
There are three important questions to ask when considering revision tarsal coalition surgery.
1) Did the coalition reoccur?
2) Does this patient have an unaddressed “flatfoot associated with tarsal coalition”?
3) Is there coalition-associated rearfoot arthritis?
Coalition reoccurrence. The first hurdle when evaluating patients after a previous coalition resection is to determine if the coalition has reoccurred. While placing interpositional material at the resected coalition site during the index operation limits this potential problem, it is indeed possible for reoccurrence if there is incomplete resection of the coalition and/or one has not performed a wide enough excision.
Additionally, an osseous coalition that has been resected may convert into a fibrous coalition, lending itself to the same clinical pain cascade as the osseous coalition. Pinpoint pain directly over the resection site may be indicative of reoccurrence.
What You Should Know About The Coalition Concomitant Flatfoot
The coalition concomitant flatfoot. An unaddressed flatfoot is often responsible for the return of symptoms after primary coalition resection, especially in a child and adolescent patient. Not only is this true of my own clinical experience but this has been the experience of other investigators who have also published peer-reviewed research papers on the subject.1,2
Historically, the flatfoot is an afterthought and only considered worthy of surgical intervention after patients fail simple resection. It has never made much sense to me why surgeons perform flatfoot reconstructions when coalition is absent (i.e., symptomatic flexible flatfoot), yet in the presence of a symptomatic tarsal coalition, the flatfoot is largely ignored.
I believe the coalition concomitant flatfoot is a pathological entity worthy of surgical intervention and have illustrated this in original research published in the Journal of Foot & Ankle Surgery in 2008 (Part I of Investigations Involving Middle Facet Coalitions).3 In January 2010, I authored a review article on this subject in Clinics in Podiatric Medicine and Surgery and will be happy to send you an electronic version of my author's copy if requested via e-mail (email@example.com ).4
It is possible for a flatfoot to progress after coalition resection and it is important to recognize that primary resection of a tarsal coalition in a rigid foot does not automatically render the foot mobile and flexible. While rearfoot motion may be restored or “allowed,” this motion is limited in comparison to a foot without coalition. Furthermore, if the patient gains motion and the flatfoot is not surgically corrected at the index operation, it is possible for the flatfoot to progress through unresolved peroneal spasm and/or natural progression of the condition. I have witnessed flat feet progress after simple resection if one does not manage this with orthotics postoperatively. This is especially concerning when it comes to the growing patient.
Another clinical concern is the symptoms that may occur from the valgus position of the rearfoot on the ankle. In 2008, we were the first to report and publish in the Journal of Foot & Ankle Surgery on specific morphologic changes of the calcaneus and fibular, which we termed “calcaneal fibular remodeling” (Part II of Investigations Involving Middle Facet Coalitions.)5 One of these changes is the formation of a pseudoarticulation that may occur between the lateral calcaneal wall and fibula. Degenerative cystic changes of the heel may occur as well. Pain in this region may suggest that secondary effects of the flatfoot are part of the pain cascade and support flatfoot correction as part of the tarsal coalition surgery, primary or revision surgery.
Is Rearfoot Arthritis A Possibility?
Coalition-associated rearfoot arthrosis. Recurrent pain after simple resection of the coalition may be due to rearfoot arthritis. It is well known that rearfoot arthritis may develop as a result of rigid tarsal coalition with or without flatfoot. Remember that rearfoot arthritis due to malalignment from flexible flatfoot does not typically occur in young people. Rearfoot arthritis may have been present at the index operation or have developed/progressed subsequently.
I have found that middle facet talocalcaneal coalitions are more commonly associated with rearfoot arthritis. This is because the middle facet coalition is really an intra-articular coalition involving a portion of the subtalar joint in comparison to an extra-articular calcaneonavicular coalition.
Arthritis presenting with primary calcaneonavicular coalitions is quite uncommon. Arthritic changes of the posterior facet of the subtalar joint was associated with moderate to severe degenerative changes on computed tomography (CT) in 43 percent of patients in Part III of Investigations Involving Middle Facet Coalitions.6 Arthritic changes may be responsible for continued pain in patients who fail tarsal coalition resection with or without flatfoot reconstructions. See Figure 1 above for a CT staging system of posterior facet arthrosis associated with middle facet talocalcaneal coalition.
Which Tests Should You Perform?
It is helpful to gather initial radiographs and any advanced imaging that a patient may have had prior to the index operation. If the patient had flatfoot, one could determine the severity prior. New standing radiographs are necessary of course. The initial magnetic resonance imaging (MRI) and CT allow for the grading of any potential arthrosis of the rearfoot.4,6 Repeat MRI and CT are helpful in determining if the coalition has reformed, to evaluate for any periarticular bone edema suggestive of increased pressure, and to evaluate and/or stage arthritic (progressive) rearfoot changes.
Bone scan has been suggested to evaluate for arthrofibrosis when other diagnostic imaging results are inconclusive.7 Diagnostic and therapeutic injections into the coalition resection site and/or intra-articularly into rearfoot joints may offer an additional clinical benefit.
Recommending Revision Tarsal Coalition Surgery
It is clear there are several variables that may be responsible for the return of pain with failed simple coalition resection. The classification system and surgical treatment algorithm that we presented for a newly diagnosed coalition also applies to revision tarsal coalition surgery as it relates to middle facet coalitions (see Figure 2).3
This classification and surgical treatment algorithm categorizes the coalition into three types depending on the presence of a flatfoot and/or the presence of rearfoot arthritis.
• Type I – flatfoot absent, arthrosis absent
• Type II – flatfoot present, arthrosis absent
• Type III – flatfoot present, arthrosis present
In the case of a failed simple resection, consider the following guidelines.
Repeat resection of the coalition may be clinically indicated if recurrence is indeed radiographically evident and in the absence of a flatfoot and/or rearfoot arthrosis. However, the patient and parent(s) should be aware that repeat resection may also fail and a more invasive approach may be necessary. If one is not going to perform revision resection of the coalition, then rearfoot fusion is the most likely course of surgical action and waiting for skeletal maturity is preferable.
If a flatfoot is present and considered to be associated with continued pain after failure of simple resection, then flatfoot reconstruction is surely indicated. The potential procedures for reconstruction are illustrated in the aforementioned algorithm based on the plane of deformity. However, the foot is likely to be rigid and repeat resection of the coalition may be necessary to mobilize the foot intraoperatively.
If arthrosis is present, then rearfoot fusion is indeed indicated to eliminate pain.
Since these patients have failed a first approach, there is a tendency to recommend more definitive reconstructive procedures to bring closure to this problem and realignment rearfoot fusion may be best option. Remember that rearfoot fusion at an early age will likely result in adjacent joint compensation in the future and one should consider this when developing a surgical plan.
Revision tarsal coalition surgery is involved and requires a detailed investigation into the etiology for the return of pain. Untreated coalition concomitant flatfoot and/or coalition-associated rearfoot arthrosis are potential reasons for continued pain after simple coalition resection.
Dr. Blitz can be reached at firstname.lastname@example.org 
1. Luhmann SJ, Schoenecker PL. Symptomatic talocalcaneal coalition resection: indications and results. J Pediatr Orthop. 1998;18(6):748-54.
2. Westberry DE, Davids JR, Oros W. Surgical management of symptomatic talocalcaneal coalitions by resection of the sustentaculum tali. J Pediatr Orthop. 2003;23(4):493-7.
3. 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.
4. Blitz NM. Pediatric & adolescent flatfoot reconstruction in combination with middle facet talocalcaneal coalition resection. Clin Podiatr Med Surg. 2010; 27(1):119-33.
5. 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.
6. 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.
7. El Rassi G, Riddle EC, Kumar SJ. Arthrofibrosis involving the middle facet of the talocalcaneal joint in children and adolescents. J Bone Joint Surg Am. 2005; 87(10):2227-31.