|
Given the challenges inherent in diagnosing and
treating tarsal coalitions, this author reviews key
clinical findings, offers keys to diagnostic imaging,
explores the merits of conservative therapy and discusses
indications for resection and arthrodesis.
Take this test online and receive your certificate instantly.
Continuing Education Course #163 | - I am pleased to introduce the latest article,
“Tarsal Coalition And Pes Planus:What Is
The Best Treatment Option?” in our CE
series. This series, brought to you by the
North American Center for Continuing
Medical Education (NACCME), consists of
complimentary CE activities that qualify for
one continuing education contact hour (.1
CEU). Readers will not be required to pay
a processing fee for this course.
As Jesse Burks, DPM, points out, an
early, accurate diagnosis can go a long way
in facilitating appropriate treatment of tarsal
coalitions. Accordingly, Dr. Burks discusses
key findings in the clinical exam and what
one should look for in diagnostic imaging.
He also shares his insights on conservative
modalities and when surgical options, such
as resection and arthrodesis, are indicated in
patients with tarsal coalitions.
At the end of this article, you’ll find a 10-
question exam. Please mark your responses on
the enclosed postcard and return it to NACCME.
This course will be posted on Podiatry
Today’s Web site (www.podiatrytoday.com)
roughly one month after the publication date.
I hope this CE series contributes to your clinical
skills.
Sincerely,
Jeff A. Hall
Executive Editor
Podiatry Today
INSTRUCTIONS: Physicians may receive one continuing
education contact hour (.1 CEU) by reading the article on pg.
70 and successfully answering the questions on pg. 74. Use the
enclosed card provided to submit your answers or log on to
www.podiatrytoday.com and respond via fax to (610) 560-
0502.
ACCREDITATION: NACCME is approved by the
Council on Podiatric Medical Education as a sponsor of continuing
education in podiatric medicine.
DESIGNATION:This activity is approved for 1 continuing
education contact hour or .1 CEU.
DISCLOSURE POLICY: All faculty participating in
Continuing Education programs sponsored by NACCME are
expected to disclose to the audience any real or apparent conflicts
of interest related to the content of their presentation.
DISCLOSURE STATEMENTS: Dr. Burks has disclosed
that he has no significant financial relationship with any
organization that could be perceived as a real or apparent conflict
of interest in the context of the subject of their presentation.
GRADING: Answers to the CE exam will be graded by
NACCME.Within 60 days, you will be advised that you have
passed or failed the exam.A score of 70 percent or above will
comprise a passing grade.A certificate will be awarded to participants
who successfully complete the exam.
TARGET AUDIENCE: Podiatrists
RELEASE DATE: May 2008
EXPIRATION DATE: May 31, 2009
LEARNING OBJECTIVES: At the conclusion of this
activity, participants should be able to:
• review the potential etiologies of tarsal coalitions;
• discuss why a muscle spasm is often present with a tarsal
coalition;
• describe common findings on conventional X-ray views of
tarsal coalitions;
• identify conservative modalities one may consider in managing
tarsal coalitions; and
• discuss indications for resection and arthrodesis in the treatment
of tarsal coalitions.
Sponsored by the North American Center for Continuing Medical
Education.
|
Most podiatric surgeons would agree that tarsal coalitions are one of the most over- and underdiagnosed conditions affecting the foot. On one hand, there are numerous specific clinical and radiographic signs for a coalition yet the global type of pain associated with this condition can often cloud an accurate diagnosis if the physician is not accustomed to seeing this type of pathology. Only with an accurate diagnosis can one develop an effective conservative or surgical plan for the patient.
A coalition is typically defined as an abnormal union, soft tissue or osseous, between two tarsal bones. Sometimes this type of bridge is present in other bones but for the sake of brevity, this article will focus only on the tarsal region. The problem with a coalition is that it either restricts or completely eliminates normal joint motion. Not only is the motion limited or absent but the restricted motion will affect the adjacent joints over a period of time. This can not only lead to pain but eventually arthrosis of those joints.
Accordingly, it is most beneficial to diagnose these coalitions early and treat them effectively. Early diagnosis reduces the chances of failed treatment and may also reduce the extent of surgical intervention that may be required.
First described by Buffon, tarsal coalitions are either: bony (synostosis), cartilaginous (synchondrosis) or fibrous (syndesmosis).1-3 Tarsal coalitions may be classified as complete or incomplete, and can be either congenital or acquired. Acquired etiologies can include trauma, infection or surgical etiologies.4-6 Surgical causes can include partial or complete arthrodesis of a joint but typically involve an unwanted partial fusion postoperatively.This can occur when one attempts to resect a coalition and there is resulting hypertrophic bone formation, which continues to block normal motion.
Additionally, the classification of coalitions can be based upon anatomic area, etiology or articular involvement. The majority of podiatric physicians are familiar with the latter form of classification because Downey’s description provides direction in appropriate surgical selection.7 This classification is very useful clinically as it factors in patient age, the type of coalition and secondary arthritic changes.The calcaneonavicular (CN) and talocalcaneal coalitions are reportedly the most common types.8 Even so, tarsal coalitions are rare and occur in approximately 1 percent of the general population.9-11
What You Should Look For In The Clinical Findings And Patient History
When examining any patient who has foot and ankle pain, consider a tarsal coalition in the list of differential diagnoses. In addition to experiencing pain in the rearfoot, patients with tarsal coalitions often have ankle pain as well. This is understandable given that limited motion in one or more joints directly affects the adjacent joints.
One must diagnose limited range of motion by not only comparing the patient’s available motion to that which is normal but also in comparison to the contralateral limb.Although there are accepted “normal values,” patients may vary widely in regard to hindfoot motion.
Accordingly, even when patients present with pain in only one foot, examination of the other limb is vital. Although inversion of the hindfoot is most commonly limited, all motion can be restricted because of secondary arthrosis, muscular spasm and equinus deformity. Even without the presence of a true spasm, the affected limb may be painful to the point of guarding and this may appear as a spasm or restricted motion. In many cases, it is beneficial to localize the subtalar joint via the sinus tarsi to be able to assess the true motion more accurately.
Finally, muscle spasm can often be present along with a coalition. In my clinical experience, the majority of patients with a symptomatic coalition will present with a peroneal spasm if the condition has been present for any appreciable amount of time.9 This is the body’s natural response to abnormal motion in the hindfoot.
|  | | This AP view of the ankle shows widening of the tibiofibular syndesmosis, enlargement
of the lateral talar process and peritalar subluxation secondary to peroneal
spastic flatfoot. |
|  | | This lateral view of the affected foot shows abnormality of the subtalar joint and deformity
of the anterior process of the calcaneus.The oblique view showed a calcaneonavicular
coalition. |
The muscles in the peroneal muscle group are strong everters of the foot and, as a result of restricted and painful motion, the muscles contract in order to limit the remaining motion. This pain forces the foot into a spastic flatfoot. Indeed, patients with a tarsal coalition may have been misdisagnosed with a painful flatfoot or a chronic ankle sprain prior to presenting to the podiatric physician.
A gait examination is also important. Often the patient externally rotates the affected limb to further prevent motion of the affected foot. Naturally, ankle, knee and hip pain can be a consequence of the abnormal gait.
The patient history is equally as important as the clinical exam. In regard to tarsal coalitions, pain is always present but often the onset is gradual and is linked with some aggravating event. In my experience, this is rarely significant trauma but something small and forgettable. An increase or change in activities can be the cause.
In my clinical experience, I have also found that a recent change in weight or height can be linked to the beginning of symptoms. Since the majority of patients with symptomatic coalitions are adolescents, parental observations are very valuable in determining an accurate diagnosis. In many young patients, gait changes, especially after activities, are especially important for the parent to note since many young people are not accurate historians. Essential Insights On Diagnostic Imaging
|  | | This postoperative view shows the typical incision for the resection of a calcaneonavicular
coalition. |
Radiological studies are invaluable in the diagnosis of a tarsal coalition. Although clinical examination often points to this joint abnormality, conventional radiographs, CT scans and MRI studies can confirm the diagnosis. The views that typically show evidence of the coalition are anteroposterior, lateral and oblique views. In addition, a calcaneal axial or “ski jump view” can provide further evaluation of a middle or posterior facet coalition. In all of these views, recognizing normal osseous anatomy is paramount to a correct diagnosis. The following are the more common findings on conventional X-rays.
Halo sign: lateral view. This is a sclerotic circle extending from the dome of the talus to below the sustentaculum tali. This appearance is from biomechanical stress that affects bony trabeculation. This is more pronounced the longer the osseous structures have had to adapt.
Talar beaking: lateral view. Here one would see bony protrusion on the dorsal aspect of the talar head. One may also view this as a dorsal talonavicular exostosis or osteophyte.
Anteater sign: lateral and oblique view. This view shows extension of the anterior beak of the calcaneus.The clinician must be suspicious of the calcaneonavicular bar even if there is incomplete bony formation in this area. A fibrous bridge can be present and still cause restricted and painful motion.12 This is another reason why localizing the area can provide the physician with a more accurate diagnosis.
Subtalar arthrosis: lateral and oblique views. With these views, one would see that degeneration of the subtalar joint is evident in longstanding deformity due to restricted motion.This may also affect the talonavicular and calcaneocuboid joints to a lesser or equal degree.13
Additionally, an AP view of the ankle is helpful to evaluate ankle pathology. Subtalar coalitions can lead to a “ball and socket” ankle joint with significant abnormality of the syndesmosis and medial and lateral malleoli.This type of deformity significantly affects the surgical outcome and one will need to have a frank discussion with the patient and/or parents about long-term treatment such as bracing, arthrodesis or implant arthroplasty.
Computed tomography scans and MRIs are very useful in determining the type of coalition as well as the extent of adjacent or related pathology. The CT scan naturally allows excellent evaluation of osseous structures but MRI can provide evidence of coalitions that may be incomplete and/or fibrous.14 Bone scans do not provide enough specificity to warrant use for this type of pathology.15 A Guide To Conservative Treatment
As with any foot and ankle condition, especially in the pediatric patient, conservative treatment is usually the initial tactic. An open discussion with the patient (and/or parents if the patient is a minor) needs to address realistic expectations for either treatment option.A patient suffering with a moderate amount of pain may often respond well to the use of antiinflammatory medication and custom orthotics. The goal of orthotic management is primarily to achieve a neutral position of the rearfoot and eliminate as much of the associated motion as possible.
Cessation of any high impact activities for approximately six weeks can also help. Again, all those involved should realize that once a coalition has become symptomatic, there is a very high likelihood that once the patient resumes normal activities, the pain will return.
In difficult cases, especially those in which a peroneal spasm is present, immobilization in a short leg cast can be effective. In addition to a localized injection of anesthetic and a corticosteroid, I have found casting to be very effective in providing at least temporary resolution of the symptoms. Physical therapy can also help address acquired pathology such as equinus and generalized foot and ankle pain. However, it cannot restore motion of the joint in which the coalition is present. Pertinent Pointers On Surgical Options
Unfortunately, many patients with a symptomatic coalition will often require surgical intervention. This is especially challenging when the podiatric surgeon must consider the patient’s age, activity level, size and adjacent pathology. Resection and arthrodesis are the two treatment choices that the podiatric surgeon faces in the recalcitrant coalition. Regardless of the type of surgery, there is a need to counsel both the patient and the family that future intervention may be required at some point.
When it comes to the adolescent patient who does not yet have adjacent joint pathology, resection is the preferable procedure.This can be very successful when resecting a calcaneonavicular coalition but is less so when one is addressing medial subtalar facet abnormalities.This is presumably due to their extraarticular nature. Badgley described resection of a calcaneonavicular coalition and the insertion of the extensor digitorum brevis muscle belly through the space created.17 Researchers have modified this approach to include condylar caps and partial tendon grafts in the area. All of these function to reduce bony regrowth in the area.18,19
In regard to resecting a calcaneonavicular coalition, I find that using cautery and bone wax is more effective and less traumatic than performing a muscular or tendinous transfer. This resection of the calcaneonavicular deformity usually occurs through a curvilinear incision over the sinus tarsi.
Once evacuation of the sinus is complete, one can resect the extensor digitorum muscle distally. If the surgeon wishes, he or she can tag the proximal end of the muscle with sutures for later transfer through the opening left after the resection. Once the muscle belly is exposed, the calcaneonavicular deformity is readily apparent. Intraoperative fluoroscopy is necessary to ensure complete resection.
Although surgical decision making will vary depending upon the individual case, arthrodesis is often the only option in patients with a failed resection or with greater than 50 percent facet involvement.20 In the failed calcaneonavicular coalition, rigid flatfoot is often the end result and a triple arthrodesis is usually required in the skeletally mature patient. When it comes to a failed talocalcaneal resection, one can perform an isolated arthrodesis of the subtalar joint if there is no pathology associated with the talonavicular or calcaneocuboid joints. In Conclusion
Although treatment options are limited for tarsal coalitions, the ability of the podiatric physician to quickly and efficiently diagnose this condition can lead to greater patient and family understanding. This in turn will lead to more realistic expectations in regard to both conservative and surgical treatment. References 1. Buffon GLL, Comte DE: Histoire Naturelle, Generale et Particulariere, Paris, tome 3, Panckoucke, 1769, page 47.
2. Bohne WH:Tarsal coalition. Curr Opin Pediatr. Feb 2001; 13(1):29-35.
3. Kumar SJ, Guille JT, Lee MS, Couto JC: Osseous and non-osseous coalition of the middle facet of the talocalcaneal joint. J Bone Joint Surg Am. Apr 1992;74(4):529-35.
4. Blakemore LC, Cooperman DR, Thompson GH:The rigid flatfoot.Tarsal coalitions. Clin Podiatr Med Surg. Jul 2000;17(3):531-55.
5. Page JC: Peroneal spastic flatfoot and tarsal coalitions. J Am Podiatr Med Assoc 77:29- 34, 1987.
6. Teramoto A, Kura H, Uchiyama E, Suzuki D,Yamashita T.Three-Dimensional Analysis of Ankle Instability After Tibiofibular Syndesmosis Injuries:A Biomechanical Experimental Study. Am J Sports Med. Oct 16 2007.
7. Downey MS:Tarsal coalitions:A surgical classification. J Am Podiatr Med Assoc 81: 187-197, 1991.
8. Barrett SE, Johnson JE. Progressive bilateral cavovarus deformity: an unusual presentation of calcaneonavicular tarsal coalition. Am J Orthop. May 2004;33(5):239-42.
9. Stormont DM, Peterson HA.The relative incidence of tarsal coalition. Clin Orthop. Dec 1983;(181):28-36.
10. Vaughn WH, Segal G:Tarsal coalition, with special reference to roentgenographic interpretation. Radiology 60:855-863, 1953.
11. Shands AR,Wentz IJ: Congenital anomalies, accessory bones and osteochondritis in the feet of 850 children. Surg Clin North Am 33; 1643-1666, 1953.
12. Oestreich AE, Mize WA, Crawford AH, Morgan RC Jr.The “anteater nose”: a direct sign of calcaneonavicular coalition on the lateral radiograph. J Pediatr Orthop. Nov-Dec 1987;7(6):709-11.
13. Crim JR, Kjeldsberg KM. Radiographic diagnosis of tarsal coalition. AJR Am J Roentgenol. Feb 2004;182(2):323-8.
14. Emery KH, Bisset GS 3rd, Johnson ND, Nunan PJ.Tarsal coalition: a blinded comparison of MRI and CT. Pediatr Radiol. Aug 1998;28(8):612-6.
15. Goldman AB, Pavlov H, Schneider R. Radionuclide bone scanning in subtalar coalitions: differential considerations. AJR Am J Roentgenol. Mar 1982;138(3):427-32.
16. Gonzalez P, Kumar SJ. Calcaneonavicular coalition treated by resection and interposition of the extensor digitorum brevis muscle. J Bone Joint Surg Am. Jan 1990;72(1):71-7.
17. Badgley CE: Coalition of the calcaneus and navicular. Arch Surg 15:75-88, 1927.
18. Collins B:Tarsal coalitions:A new surgical procedure. Clin Podiatr 1987; 4(1):75-98.
19. Kumar SJ, Guille JT, Lee MS, Couto JC: Osseous and non-osseous collation of the middle facet of the talocalcaneal joint. JBJS 1992, 74A:71-77.
20. Wilde PH,Torode IP, Dickens DR, Cole WG: Resection for symptomatic talocalcaneal coalition. JBJS (Br) 1194; 76B:797-801. For related articles, see “How To Detect And Treat Tarsal Coalitions” in the November 2004 issue of Podiatry Today or “A Closer Look At Tarsal Tunnel Syndrome” in the November 2003 issue. Also check out the archives at www.podiatrytoday.com. |
