How Would You Treat a 22-Year-Old Professional Ballet Dancer With an Os Trigonum and Fluid Around Her Flexor Hallucis Longus Tendon Sheath Seen on Magnetic Resonance Imaging?
The first thing that is important to define when a “professional” ballet dancer presents to your office is exactly what level of dance they are professional in. There are several levels of dance, and all are legitimate activities and are important for that particular dancer. The question that must be answered in a professional ballet dancer is how professional? How many weeks a year does she dance professionally, and does she have other jobs in addition to dance? Does the dancer have another job to supplement her income that does not involve dance? A full-time professional dancer is significantly more motivated, and the rehabilitation necessary to come back from any serious injury requires “professional” motivation. Hamilton et al reported that the postoperative functional results in flexor hallucis longus (FHL) tendinitis patients were significantly better in dancers who were professionals.1 Secondly, the determination of what discipline of dance they are practicing is important. In addition, women and men have different types of injuries and dance requirements. A classical ballet dancer who is a female will be dancing en pointe, and because of that will have a unique stress on the posterior aspect of her ankle and her FHL. Classical ballet is the only dance regimen that requires the dancer to go en pointe, and females are the only dancers who go en pointe. The reality of pointe dancing is the FHL is required to allow the dancer to get on her toes. If the dancer is doing some modern dance that is mostly barefoot or multiple disciplines of dance (ie, jazz, hip hop, tap), that may allow us to guide her to a more appropriate type of dance. The male ballet dancer must be able to stand on his forefoot but not en pointe. In addition, he is required to do lifts and carries that are not required of the females.
Once the demographic of this particular patient is determined, the next important thing is to get a history. From a young age, professional dancers are dancing 11 to 12 months a year. It is important to determine exactly when the problem began and the specific symptoms. For this patient, most commonly the symptoms are described as fullness and pain in the posteromedial ankle after a long period of dance. More specifically, the dancer will complain of symptoms when rehearsing and doing a performance. Often there is a change in the dance surface or in the dance intensity that can precipitate the symptoms. Early on, she will almost always ignore and/or dance through the pain with self-administered local ice and oral anti-inflammatories. It is important to determine how much of this self-administered treatment she is receiving in order to truly determine the severity of the symptoms. The perception that the involved ankle has less motion than the contralateral ankle can add to the story. Most often the pain is chronic in nature, and rarely is there an acute episode. By the time professional dancers seek medical care, they have already tried a number of things, including wrapping their ankles and rest.
It is important at this time to understand the specifics of the anatomy in the posterior ankle (Figure 26-1). I often like to describe the posterior ankle as a sandwich waiting to happen. The tibia, talus, and calcaneus are stacked on each other in a very small space. If the talus has either a congenital potentially loose posterior extension, which is termed an os trigonum, or a fixed posterior extension, often called the stieda process, this posterior extension can get crushed between the tibia and the calcaneus in an athlete who spends most of his or her day in and out of forced plantarflexion. There are also key thickened soft tissue structures that can cause symptoms; specifically, the posterior talofibular ligament and the posterior tibiofibular ligament. This “posterior impingement” is not just a bony impingement but can often be a soft tissue impingement that can present with variants. The first variant in the soft tissue impingement is more of a posterolateral impingement. These patients will complain of posterolateral pain, which is most often a soft tissue impingement, and then a posterocentral and posteromedial pain, which again can be a soft tissue variant of this. Finally, the anatomy of the FHL in the back of the ankle is important to note. The FHL runs directly on the os trigonum or the posterior aspect of the talus on the medial aspect of that structure. The posterior talus is the deep lateral portion to the groove and tunnel that the FHL runs in. Most often, if there is posterior impingement, there is also FHL tendinitis because the 2 structures run so closely together. In addition, an isolated FHL tendinitis can masquerade as a posterior impingement, again because of the anatomic relationship. The FHL runs in a very tight sheath and can get a tenovaginitis in that tendon sheath. The medial position of the FHL is the reason that the symptoms are most often medial.
Figure 26-1. Schematic of the anatomy of the posterior ankle.
The directed physical examination is extremely important and straightforward. There are 2 specific tests that are important in these patients. First, a forced plantarflexion test. This is done with the patient’s leg bent while the examiner actively plantarflexes the ankle. If there is a significant posterior impingement lesion, this will elicit symptoms consistent with the patient’s problem. In addition, asymmetric plantarflexion range of motion can be seen if the plantarflexion test is done bilaterally. The second specific test is a direct palpation on the FHL. Anatomically, this is just behind the neurovascular bundle. Often these patients will be misdiagnosed with Achilles tendinitis because the pain is more posterior than anterior. Once the area of maximum tenderness is palpated medially, it is easy to follow the FHL anteriorly underneath the sustentaculum tali. Most often, in a tendinitis situation, the tenderness goes all the way out. It is very rare to elicit FHL tendinitis symptoms with fixed dorsiflexion of the big toe, so this test is rarely helpful.
The radiographic evaluation of these patients is fairly straightforward. In the office, it is very easy to get 3 views of the ankle, and most often any type of bony impingement lesions such as the large stieda process or an os trigonum can be seen quite readily. In addition, it can be helpful for illustrative purposes to get a full plantarflexion x-ray in the office. This often will show the mechanism of the posterior impingement, and it can be instructive to the patient to see that relationship radiographically. Magnetic resonance imaging (MRI) can also be helpful because it allows us to evaluate the FHL tendon itself. The MRI can show if the FHL has attritional tears that may have some prognostic indicators in the treatment of this condition. Edema in the os trigonum or the posterior talar process can also be seen.
The initial treatment options should be conservative. Most of these patients, regardless of their level of dance, will get better with a course of physical therapy and rest. The difficulty is getting a professional ballet dancer to rest. If you can get the dancer to take 6 weeks off with a course of physical therapy, friction massage to the FHL, as well as various modalities in that area, the results are good and certainly will keep the dancer off the stage for a shorter period of time than surgery. At the same time, I almost always will have the patient spend some time with her favorite ballet master. A private lesson with a skilled instructor will often illuminate flaws with the dancer’s technique that have been longstanding and often may have caused the problem in the first place. All of this can be done during that 6-week period.
The surgical treatment is divided into open and arthroscopic. The open treatment is an incision just posterior to the neurovascular bundle. The neurovascular bundle is exposed. It is important to retract the neurovascular bundle posteriorly and not anteriorly. If you retract it anteriorly, it will require the resection of the medial calcaneal branches, and the patient may now have a better ankle, but also a numb heel. Once the neurovascular bundle is retracted posteriorly, the FHL sheath can be opened easily. It should be released all the way throughout its entire length. At that time a tenosynovectomy plus/minus repair of a tear can be done. Once that is completed, the FHL can be retracted, again posteriorly exposing the posterior aspect of the ankle. The os trigonum and/or prominent talar stieda process can be seen and resected. If the os trigonum is loose and removed easily, it is important to be able to plantarflex fully and have your small finger not be crushed. If it continues to be a problem, then a portion of the posterior talus should be resected with an osteotome or burr. An intraoperative x-ray should be done to make sure that the decompression is complete before closing.
The arthroscopic treatment is one that I have made almost routine in my practice in the last 5 years. Dr. van Dijk from the Netherlands has reported his series of prone posterior arthroscopic ankle and subtalar decompressions for posterior impingement, and my experience has been similar.2 The portals for the prone arthroscopy are to the medial and lateral side of the Achilles tendon at the level of the tip of the fibula. This operation for an os trigonum is an extra-articular arthroscopic operation. I will use a 4.0 scope with a 4.0 shaver to perform this surgery. It is much more like a shoulder scope than traditional anterior ankle arthroscopy. Once the back of the ankle is exposed, the os trigonum is clearly seen. If it is loose, it can be removed with minimal difficulty with the working portal being the medial side. Of note, all of the work should be kept lateral to the FHL as the neurovascular bundle sits directly medial to the FHL. Once the os trigonum is removed, the FHL sheath is easily exposed. I use a small shaver to débride the sheath. It is important to go at least 1 cm down the sheath to get a complete release of the tendon. At the same time, it is quite easy to do a tenosynovectomy of the involved tendon with a shaver. If there is a tear, I most often will débride the tear with no repair necessary.
The results for this procedure in professional dancers have been excellent. The largest series is Bill Hamilton’s out of New York, in which he got his professionals back to full dance over 95% of the time.1 His results were not as good in amateurs, and this is more than anything, in my opinion, the difficulty with the open treatment. The rehabilitation and resultant scar tissue from the surgery requires a very intense focus for the patient. My results with arthroscopic treatment have seen a quicker return to dance for even the most casual dancer. It is now the standard in my practice.3
The 22-year-old professional ballet dancer is a challenging but rewarding athlete to treat. Most often this condition can be treated conservatively, but open or arthroscopic treatment is certainly easily defended if needed. In my hands, the arthroscopic treatment is superior in results and ease of rehabilitation.
1. Hamilton WG, Geppert MJ, Thompson FM. Pain in the posterior aspect of the ankle in dancers. Differential diagnosis and operative treatment. J Bone Joint Surg Am. 1996;78(10):1491-1500.
2. van Dijk CN, Scholten PE, Krips R. A 2-portal endoscopic approach for diagnosis and treatment of posterior ankle pathology. Arthroscopy. 2000;16(8):871-876.
3. van Dijk CN. Hindfoot endoscopy for posterior ankle pain. Instr Course Lect. 2006;55:545-554.