The Journal of Foot & Ankle Surgery 53 (2014) 787–790
Contents lists available at ScienceDirect
The Journal of Foot & Ankle Surgery journal homepage: www.jfas.org
Magnetic Resonance Imaging, Computed Tomography, and Radiographic Correlation of Nonunion of the Posteromedial Tubercle of the Talus: A Case Report Pradeep Albert, MD 1, Jalpen Patel, DPM 2, Joshua I. Katz, BS 3, Frank Loria, BS 4, John Parnell, MD 5, Marc Brenner, DPM 6 1
Professor, New York College of Podiatric Medicine, New York, NY Resident, St. Barnabas Medical Center, Livingston, NJ Student, New York College of Osteopathic Medicine, Old Westbury, NY 4 University of Delaware, Newark, DE 5 Practicing Physician, Medical Arts Radiology, Commack, NY 6 Attending Physician, Long Island Jewish Hospital, New Hyde Park, NY 2 3
a r t i c l e i n f o
a b s t r a c t
Level of Clinical Evidence: 4
Fracture of the posteromedial tubercle of the talus is an uncommon injury that is often missed on plain radiographs. In the present report, we describe the case of an adult male with a chronic nonunited fracture of the medial tubercle of the posterior process of the talus after having undergone clinical and radiographic evaluation in a community hospital emergency department. A review of the computed tomographic, magnetic resonance imaging, and plain film radiographic findings associated with nonunion of the posteromedial tubercle of the talus is also presented. Ó 2014 by the American College of Foot and Ankle Surgeons. All rights reserved.
Keywords: Cedell’s fracture flexor hallucis longus os trigonum radiograph Stieda’s process trauma
Fractures of the talus account for of less than 1% of all reported fractures and constitute only 3% to 6% of fractures occurring in the foot (1). Fracture of the posteromedial tubercle of the talus is even rarer and is an atypical injury that is commonly missed on anteroposterior and lateral radiographs, causing the injury to be misdiagnosed as an ankle sprain (2). Fracture of the posteromedial tubercle can occur when the pronated foot is forcefully dorsiflexed, thereby creating tension in the posterior tibiotalar portion of the deltoid ligament. This fracture was described by Cedell (3) as a sports injury, hence the eponym “Cedell’s fracture.” Avulsion fracture of the posteromedial tubercle of the talus has also been described as a result of motor vehicle accidents (4). To avoid nonunion and chronic rearfoot pain, it is important that this injury be diagnosed early in its clinical course (2). Approximately 25% of the posterior articular facet of the subtalar joint is covered by the posterior process of the talus; hence, accurately diagnosing its fracture is of utmost importance to prevent subtalar joint arthritis (5). Cross-sectional imaging, including computed tomography (CT) and
Financial Disclosure: None reported. Conflict of Interest: None reported. Address correspondence to: Pradeep Albert, MD, Professor, New York College of Podiatric Medicine, 214 Wall Street, Huntington, NY 11743. E-mail address: [email protected] (P. Albert).
magnetic resonance imaging (MRI), can be useful in identifying the presence of this rare talar fracture. The goal of the present case report is to raise physician awareness in the use of advanced diagnostic imaging studies to rule out fracture of posteromedial process of the talus. Case Report A 34-year-old male presented to our outpatient orthopedic clinic with a complaint of chronic persistent right ankle and rearfoot pain. He related a history that included injuring his right ankle approximately 6 years earlier, resulting in pain and swelling localized to his right ankle since the original injury. At the time of the original injury, he presented to a community hospital where radiographs were obtained. He was told that he had an ankle sprain with no associated fracture, and he was advised to wear an ankle brace along with getting physical therapy. He was also advised to follow-up with an orthopedic clinic if the pain persisted. He never partook in any of the physical therapy sessions or followed up with any clinic on this issue owing to insurance-related issues. On presentation to our clinic, the patient did not have a noticeable limp and denied having recent trauma to his right ankle. The patient had been self-treating himself from the point of his initial injury with the use of a lace-up ankle brace and nonprescription nonsteroidal
1067-2516/$ - see front matter Ó 2014 by the American College of Foot and Ankle Surgeons. All rights reserved. http://dx.doi.org/10.1053/j.jfas.2014.07.003
788
P. Albert et al. / The Journal of Foot & Ankle Surgery 53 (2014) 787–790
anti-inflammatory drugs yet continued to have chronic medial ankle pain. The patient noted that he had had pain relief initially with the use of the ankle brace and pain medications but was never completely pain free. The patient had tried to reduce his physical weightbearing activities because that helped lessen the pain. The patient had kept putting off visiting an orthopedic doctor for all this time but did not give us a specific reason. The physical examination of the patient’s ankle revealed pain with resistance against motion of the right flexor hallucis longus tendon; however, no pain was elicited with passive range of motion. Mild instability was noted with stress to the right deltoid ligament, and a small palpable structure was also noted inferior to the posterior aspect of medial malleolus. Standard foot radiographs (Fig. 1) revealed findings suggestive of either a nonunited fracture of the posteromedial tubercle of the talus or hypertrophic ossification of the talus where the deltoid ligament attaches. From these findings, an initial diagnosis of a chronic deltoid ligament sprain secondary to medial ankle injury was made. Treatment was initiated with the use of a J strap to stabilize the deltoid ligament and the use of a controlled ankle motion (CAM) walker on ambulation. MRI scans with no contrast were ordered in an effort to more precisely assess the ligaments at the medial aspect of the talus. Inspection of the T1- and T2-weighted MRI sequences demonstrated nonunion of the posteromedial tubercle and hypertrophic ossification of the tubercle. However, no increased signal was present on the fluid-sensitive image sequences to suggest acute injury; thus, the possibility of chronic nonunion of the posteromedial tubercle of the talus was considered (Figs. 2 and 3). The posterolateral tubercle (Stieda’s process, or, when separate, the os trigonum) appeared to be intact. After consideration of the MRI results, 64-detector axial CT images of the right ankle were performed to better visualize the osseous anatomy (Fig. 4). The CT scan showed a nondisplaced chronic nonunited fracture segment measuring 1.6 cm 1.0 cm 1.8 cm. A fibrocystic interface was also present between the fragment and the parent talus, which was identified on additional review. Small post-traumatic degenerative spurring involving the posterior aspect of the posterior subtalar articulation was also present, indicating chronic nonunion of the fracture segment. Moreover, small heterotrophic foci of ossification
Fig. 1. Oblique radiographic view of the right ankle revealing hypertrophic bone suggestive of a chronic, nonunited fracture of the posteromedial tubercle of the talus.
Fig. 2. Magnetic resonance images showing a nonunited fracture of the posteromedial tubercle of the talus.
were seen within the deep fibers of the deltoid ligament, also consistent with chronic injury (Fig. 5). On retrospective analysis of the presenting radiographs, a fracture of the posteromedial tubercle of the talus was found, and the initial diagnosis determined from the clinical and standard radiographic findings was refined with the more precise diagnostic information available from the MRI and CT scans. A final diagnosis of chronic nonunion of the posteromedial tubercle of the talus was made 1 week after his initial presentation to our clinic and more than 6 years after his initial ankle injury. At this point, considering the chronicity of the injury and his persistent pain, the patient was offered surgical intervention, which included excision of the nonunited fracture fragment. The patient refused any surgical treatment option because it involved being non-weightbearing after the surgery. The patient also declined the suggestion to apply a short leg cast for approximately 6 weeks to immobilize his ankle, which, as explained to the patient, could help with healing of the nonunion. The patient was subsequently treated using an Arizona brace, which is an ankle-stabilizing orthosis and acetaminophen with codeine for pain relief. The patient continued with monthly visits and was repeatedly advised to rethink his treatment decisions. At his final follow up visit, 10 months after his presentation to our clinic and almost 7 years after the original injury, he continued to have residual pain. However, he had been noncompliant with the use of the Arizona brace and had declined to participate in physical therapy or any other therapeutic treatment modalities. He was eventually lost to follow-up.
P. Albert et al. / The Journal of Foot & Ankle Surgery 53 (2014) 787–790
789
Fig. 3. Drawing of the posteromedial tubercle of the talus and groove for the flexor hallucis longus (illustration by Jalpen Patel).
Fig. 5. Computed tomographic scan showing small, heterotrophic foci of ossification in the deep fibers of the deltoid ligament, consistent with chronic injury.
Discussion
direction of the motion of the foot and ankle, fracture of the posteromedial tubercle of the talus usually involves a high-speed mechanism, such as that which occurs in association with athletic events and motor vehicle accidents (9). However, it is easy to misdiagnose this particular fracture using plain film radiographs, because the defect involves a small portion of the talus that is situated in an anatomic location where superimposition of the lateral malleolus in the lateral radiographic projection and the anterior portions of the talus in the mortise and anteroposterior radiographic projections conceals the fracture fragment. Sometimes, modified radiographs such as an oblique view, in which the foot is 45 externally rotated, can be used if a fracture is suspected and does not show up on routine radiographs, although nondisplaced fractures can be challenging to visualize (5). In such cases, the use of computer regenerated axial imaging, such as MRI and CT, can be helpful in ascertaining the diagnosis, determining the size of the fracture fragment and degree of displacement. Also, in the case of a chronic injury, the presence of fibrous tissue, ligamentous disruption, and inflammation can also be determined. Therefore, the importance of using these advanced imaging studies cannot be overemphasized when fracture or nonunion of the posteromedial process of the talus is suspected. The key to suspecting fracture of the posteromedial process of the talus is pain and edema localized to the posteromedial aspect of the ankle, immediately inferior to the posterior margin of the medial malleolus. The posterior talus consists of both the medial and the lateral tubercles and the groove for passage of the flexor hallucis longus (FHL) tendon between the 2 tubercles (Fig. 3). When fracture of the posteromedial tubercle goes undiagnosed, the FHL can slip out of the groove, and plantarflexion of the ankle can injure the tendon and its sheath (9). The FHL tendon can also interpose between the fracture fragment and the talus, causing potential tear and tendonitis (5). If diagnosis of the fracture is delayed, chronic posteromedial ankle pain or tarsal tunnel syndrome can develop. If fracture displacement is less than 3 mm and no joint involvement is observed, closed reduction with casting for at least 6 weeks is recommended. If displacement is greater than 3 mm or symptomatic subtalar joint involvement is present, open reduction with internal fixation (ORIF) or excision of the
Isolated fracture of the medial tubercle of the posterior process of the talus is a rare injury (6). The first case of this injury was reported in 1974 by Cedell (3), who described it as an avulsion mechanism associated with forced dorsiflexion of the pronated foot, where the posterior tibiotalar ligament is torn from its attachment to the talus (7,8). Other mechanisms associated with the incidence of this fracture include direct trauma, inversion force to the foot, and maximum forced plantarflexion of the ankle, with the posterior talar process impinging between the calcaneus and tibia (1,5). Regardless of the
Fig. 4. Computed tomographic scan showing a nonunited fracture of the posteromedial tubercle of the talus.
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P. Albert et al. / The Journal of Foot & Ankle Surgery 53 (2014) 787–790
fracture fragment is advised to decrease the possibility of subtalar degenerative arthritis (1). Wolf and Heckman (6) reported that the best treatment of a comminuted fracture or symptomatic nonunion of the posteromedial tubercle of the talus was surgical excision of the fracture fragments. Our patient did not meet the criteria for internal surgical fixation, because no displacement of the fracture fragment or subtalar joint involvement was present. However, surgical intervention for removal of the hypertrophic ossicle was recommended, which the patient refused. Successful internal fixation has been reported in published studies for fracture of the posteromedial process of the talus. In a case report by Chen et al (10), the authors showed that ORIF using a screw for a displaced fracture of the medial tubercle of the posterior process of the talus proved effective. After the procedure, their patient used a non-weightbearing splint for 6 weeks, after which the screw was removed (10). The classic approach for ORIF of this fracture type is the posteromedial approach; however, there is an increased risk of damage to the adjacent neurovascular structures. Mendicino et al (11) recommended a method termed the oblique medial malleolar osteotomy approach for the management of medial talar dome lesions. However, the same method can be used for ORIF of the posteromedial tubercle fracture to minimize the likelihood of neurovascular insult. A longitudinal 5- to 7-cm incision is made over the medial malleolus to create an oblique osteotomy angled 45 to the tibial plafond. This technique ensures proper visualization of the posterior talar processes and helps preserve the deltoid ligament (11). Letonoff et al (1) published a case report in which they performed ORIF using the oblique medial malleolar osteotomy approach. They used two 2-0 mm bioabsorbable screws for fixation and found complete healing of the fracture site. However, the patient developed subtalar joint arthritis after 16 months in the postoperative period (1). Few reports have described the use of closed reduction and physical therapy for the treatment of nondisplaced fractures of the posteromedial tubercle of the talus (7,10). In such cases, initial immobilization and non-weightbearing is required, followed by a period of appropriate rehabilitation exercises to ensure optimum results. Nonetheless, closed reduction can be rendered unsuccessful if the FHL tendon is interposed between the fracture fragments, such as reported by Dougall and Ashcroft (12). A case report published in 1996 used immobilization in a patient with a non-weightbearing short leg cast for 7 weeks, and the patient reported no symptoms after that period (8). In another case study, the fracture was diagnosed 4 weeks after the initial injury, and the patient was placed in a fiberglass cast for 2 weeks followed by CAM walker for 4 weeks. The investigators noted progressive osseous union at 6 weeks (5). Kim et al (13) performed a retrospective study of 5 patients with fracture of the posteromedial tubercle of the talus. Of the 5 patients, 2 had been diagnosed acutely, treated with immobilization in a
non-weightbearing cast, and achieved excellent results. The remaining 3 patients were initially misdiagnosed and developed chronic medial ankle pain. They eventually underwent delayed surgical excision of the fracture fragment and reported pain relief comparable to that of the first group (13). For our patient with a chronic nonunited fracture, in whom the fracture had been initially misdiagnosed, the treatment course was not clear. We had to use our clinical judgment and considered the patient’s compliance to treatment. We suggested both surgical and conservative therapy; however, the patient opted out of both. One limitation of our case report was the absence of any therapeutic interventions used to successfully treat the fracture and the absence of follow-up imaging studies to document whether any healing had occurred. In conclusion, fracture of the posteromedial tubercle of the talus is a rare injury. Because this injury is uncommon, it is often misdiagnosed. After our patient had injured his ankle 6 years earlier, he continued to have chronic pain and swelling localized to his right rearfoot and ankle. In cases such as this, in which an accurate diagnosis has finally been made years after the initial injury, crosssectional imaging studies such as MRI and CT can be helpful determine the precise nature of the injury.
References 1. Letonoff EJ, Najarian CB, Suleiman J. The posteromedial process fracture of the talus: a case report. J Foot Ankle Surg 41:52–56, 2002. 2. Ebraheim NA, Patil V, Nicholas FC, Liu X. Diagnosis of medial tubercle fractures of the talar posterior process using oblique views. Injury 38:1313–1317, 2007. 3. Cedell CA. Rupture of the posterior talotibial ligament with the avulsion of a bone fragment of the talus. Acta Orthop Scand 45:454–461, 1974. 4. Berkowitz MJ, Kim DH. Process and tubercle fractures of the hindfoot. J Am Acad Orthop Surg 13:492–502, 2005. 5. O’Loughlin P, Sofka CM, Kennedy JG. Fracture of the medial tubercle of the posterior process of the talus: MRI appearance with clinical follow-up. HSS J 5:161–164, 2009. 6. Wolf RS, Heckman JD. Case report: fracture of the posterior medial tubercle of the talus secondary to direct trauma. Foot Ankle Int 19:255–258, 1998. 7. Gutierres M, Cabral T, Miranda A, Almeida L. Fractures of the posteromedial process of the talus: a report of two cases. Int Orthop 22:394–396, 1998. 8. Kim DH, Hrutkay JM, Samson MM. Fracture of the medial tubercle of the posterior process of the talus: a case report and literature review. Foot Ankle Int 17:186–188, 1996. 9. Kou JX, Fortin PT. Commonly missed peritalar injuries. J Am Acad Orthop Surg 17:775–786, 2009. 10. Chen C-W, Hsu S-Y, Wei Y-S. Fracture of the medial tubercle of the posterior process of the talus. Formosan J Musculoskel Disord 2:62–65, 2011. 11. Mendicino RW, Lee MS, Grossman JP, Shromoff PJ. Oblique medial malleolar osteotomy for the management of talar dome lesions. J Foot Ankle Surg 37:516–523, 1998. 12. Dougall TW, Ashcroft GP. Flexor hallucis longus tendon interposition in a fracture of the medial tubercle of the posterior process of the talus. Injury 28:551–552, 1997. 13. Kim DH, Berkowitz MJ, Pressman DN. Avulsion fractures of the medial tubercle of the posterior process of the talus. Foot Ankle Int 24:172–175, 2003.
Contents lists available at ScienceDirect
The Journal of Foot & Ankle Surgery journal homepage: www.jfas.org
Magnetic Resonance Imaging, Computed Tomography, and Radiographic Correlation of Nonunion of the Posteromedial Tubercle of the Talus: A Case Report Pradeep Albert, MD 1, Jalpen Patel, DPM 2, Joshua I. Katz, BS 3, Frank Loria, BS 4, John Parnell, MD 5, Marc Brenner, DPM 6 1
Professor, New York College of Podiatric Medicine, New York, NY Resident, St. Barnabas Medical Center, Livingston, NJ Student, New York College of Osteopathic Medicine, Old Westbury, NY 4 University of Delaware, Newark, DE 5 Practicing Physician, Medical Arts Radiology, Commack, NY 6 Attending Physician, Long Island Jewish Hospital, New Hyde Park, NY 2 3
a r t i c l e i n f o
a b s t r a c t
Level of Clinical Evidence: 4
Fracture of the posteromedial tubercle of the talus is an uncommon injury that is often missed on plain radiographs. In the present report, we describe the case of an adult male with a chronic nonunited fracture of the medial tubercle of the posterior process of the talus after having undergone clinical and radiographic evaluation in a community hospital emergency department. A review of the computed tomographic, magnetic resonance imaging, and plain film radiographic findings associated with nonunion of the posteromedial tubercle of the talus is also presented. Ó 2014 by the American College of Foot and Ankle Surgeons. All rights reserved.
Keywords: Cedell’s fracture flexor hallucis longus os trigonum radiograph Stieda’s process trauma
Fractures of the talus account for of less than 1% of all reported fractures and constitute only 3% to 6% of fractures occurring in the foot (1). Fracture of the posteromedial tubercle of the talus is even rarer and is an atypical injury that is commonly missed on anteroposterior and lateral radiographs, causing the injury to be misdiagnosed as an ankle sprain (2). Fracture of the posteromedial tubercle can occur when the pronated foot is forcefully dorsiflexed, thereby creating tension in the posterior tibiotalar portion of the deltoid ligament. This fracture was described by Cedell (3) as a sports injury, hence the eponym “Cedell’s fracture.” Avulsion fracture of the posteromedial tubercle of the talus has also been described as a result of motor vehicle accidents (4). To avoid nonunion and chronic rearfoot pain, it is important that this injury be diagnosed early in its clinical course (2). Approximately 25% of the posterior articular facet of the subtalar joint is covered by the posterior process of the talus; hence, accurately diagnosing its fracture is of utmost importance to prevent subtalar joint arthritis (5). Cross-sectional imaging, including computed tomography (CT) and
Financial Disclosure: None reported. Conflict of Interest: None reported. Address correspondence to: Pradeep Albert, MD, Professor, New York College of Podiatric Medicine, 214 Wall Street, Huntington, NY 11743. E-mail address: [email protected] (P. Albert).
magnetic resonance imaging (MRI), can be useful in identifying the presence of this rare talar fracture. The goal of the present case report is to raise physician awareness in the use of advanced diagnostic imaging studies to rule out fracture of posteromedial process of the talus. Case Report A 34-year-old male presented to our outpatient orthopedic clinic with a complaint of chronic persistent right ankle and rearfoot pain. He related a history that included injuring his right ankle approximately 6 years earlier, resulting in pain and swelling localized to his right ankle since the original injury. At the time of the original injury, he presented to a community hospital where radiographs were obtained. He was told that he had an ankle sprain with no associated fracture, and he was advised to wear an ankle brace along with getting physical therapy. He was also advised to follow-up with an orthopedic clinic if the pain persisted. He never partook in any of the physical therapy sessions or followed up with any clinic on this issue owing to insurance-related issues. On presentation to our clinic, the patient did not have a noticeable limp and denied having recent trauma to his right ankle. The patient had been self-treating himself from the point of his initial injury with the use of a lace-up ankle brace and nonprescription nonsteroidal
1067-2516/$ - see front matter Ó 2014 by the American College of Foot and Ankle Surgeons. All rights reserved. http://dx.doi.org/10.1053/j.jfas.2014.07.003
788
P. Albert et al. / The Journal of Foot & Ankle Surgery 53 (2014) 787–790
anti-inflammatory drugs yet continued to have chronic medial ankle pain. The patient noted that he had had pain relief initially with the use of the ankle brace and pain medications but was never completely pain free. The patient had tried to reduce his physical weightbearing activities because that helped lessen the pain. The patient had kept putting off visiting an orthopedic doctor for all this time but did not give us a specific reason. The physical examination of the patient’s ankle revealed pain with resistance against motion of the right flexor hallucis longus tendon; however, no pain was elicited with passive range of motion. Mild instability was noted with stress to the right deltoid ligament, and a small palpable structure was also noted inferior to the posterior aspect of medial malleolus. Standard foot radiographs (Fig. 1) revealed findings suggestive of either a nonunited fracture of the posteromedial tubercle of the talus or hypertrophic ossification of the talus where the deltoid ligament attaches. From these findings, an initial diagnosis of a chronic deltoid ligament sprain secondary to medial ankle injury was made. Treatment was initiated with the use of a J strap to stabilize the deltoid ligament and the use of a controlled ankle motion (CAM) walker on ambulation. MRI scans with no contrast were ordered in an effort to more precisely assess the ligaments at the medial aspect of the talus. Inspection of the T1- and T2-weighted MRI sequences demonstrated nonunion of the posteromedial tubercle and hypertrophic ossification of the tubercle. However, no increased signal was present on the fluid-sensitive image sequences to suggest acute injury; thus, the possibility of chronic nonunion of the posteromedial tubercle of the talus was considered (Figs. 2 and 3). The posterolateral tubercle (Stieda’s process, or, when separate, the os trigonum) appeared to be intact. After consideration of the MRI results, 64-detector axial CT images of the right ankle were performed to better visualize the osseous anatomy (Fig. 4). The CT scan showed a nondisplaced chronic nonunited fracture segment measuring 1.6 cm 1.0 cm 1.8 cm. A fibrocystic interface was also present between the fragment and the parent talus, which was identified on additional review. Small post-traumatic degenerative spurring involving the posterior aspect of the posterior subtalar articulation was also present, indicating chronic nonunion of the fracture segment. Moreover, small heterotrophic foci of ossification
Fig. 1. Oblique radiographic view of the right ankle revealing hypertrophic bone suggestive of a chronic, nonunited fracture of the posteromedial tubercle of the talus.
Fig. 2. Magnetic resonance images showing a nonunited fracture of the posteromedial tubercle of the talus.
were seen within the deep fibers of the deltoid ligament, also consistent with chronic injury (Fig. 5). On retrospective analysis of the presenting radiographs, a fracture of the posteromedial tubercle of the talus was found, and the initial diagnosis determined from the clinical and standard radiographic findings was refined with the more precise diagnostic information available from the MRI and CT scans. A final diagnosis of chronic nonunion of the posteromedial tubercle of the talus was made 1 week after his initial presentation to our clinic and more than 6 years after his initial ankle injury. At this point, considering the chronicity of the injury and his persistent pain, the patient was offered surgical intervention, which included excision of the nonunited fracture fragment. The patient refused any surgical treatment option because it involved being non-weightbearing after the surgery. The patient also declined the suggestion to apply a short leg cast for approximately 6 weeks to immobilize his ankle, which, as explained to the patient, could help with healing of the nonunion. The patient was subsequently treated using an Arizona brace, which is an ankle-stabilizing orthosis and acetaminophen with codeine for pain relief. The patient continued with monthly visits and was repeatedly advised to rethink his treatment decisions. At his final follow up visit, 10 months after his presentation to our clinic and almost 7 years after the original injury, he continued to have residual pain. However, he had been noncompliant with the use of the Arizona brace and had declined to participate in physical therapy or any other therapeutic treatment modalities. He was eventually lost to follow-up.
P. Albert et al. / The Journal of Foot & Ankle Surgery 53 (2014) 787–790
789
Fig. 3. Drawing of the posteromedial tubercle of the talus and groove for the flexor hallucis longus (illustration by Jalpen Patel).
Fig. 5. Computed tomographic scan showing small, heterotrophic foci of ossification in the deep fibers of the deltoid ligament, consistent with chronic injury.
Discussion
direction of the motion of the foot and ankle, fracture of the posteromedial tubercle of the talus usually involves a high-speed mechanism, such as that which occurs in association with athletic events and motor vehicle accidents (9). However, it is easy to misdiagnose this particular fracture using plain film radiographs, because the defect involves a small portion of the talus that is situated in an anatomic location where superimposition of the lateral malleolus in the lateral radiographic projection and the anterior portions of the talus in the mortise and anteroposterior radiographic projections conceals the fracture fragment. Sometimes, modified radiographs such as an oblique view, in which the foot is 45 externally rotated, can be used if a fracture is suspected and does not show up on routine radiographs, although nondisplaced fractures can be challenging to visualize (5). In such cases, the use of computer regenerated axial imaging, such as MRI and CT, can be helpful in ascertaining the diagnosis, determining the size of the fracture fragment and degree of displacement. Also, in the case of a chronic injury, the presence of fibrous tissue, ligamentous disruption, and inflammation can also be determined. Therefore, the importance of using these advanced imaging studies cannot be overemphasized when fracture or nonunion of the posteromedial process of the talus is suspected. The key to suspecting fracture of the posteromedial process of the talus is pain and edema localized to the posteromedial aspect of the ankle, immediately inferior to the posterior margin of the medial malleolus. The posterior talus consists of both the medial and the lateral tubercles and the groove for passage of the flexor hallucis longus (FHL) tendon between the 2 tubercles (Fig. 3). When fracture of the posteromedial tubercle goes undiagnosed, the FHL can slip out of the groove, and plantarflexion of the ankle can injure the tendon and its sheath (9). The FHL tendon can also interpose between the fracture fragment and the talus, causing potential tear and tendonitis (5). If diagnosis of the fracture is delayed, chronic posteromedial ankle pain or tarsal tunnel syndrome can develop. If fracture displacement is less than 3 mm and no joint involvement is observed, closed reduction with casting for at least 6 weeks is recommended. If displacement is greater than 3 mm or symptomatic subtalar joint involvement is present, open reduction with internal fixation (ORIF) or excision of the
Isolated fracture of the medial tubercle of the posterior process of the talus is a rare injury (6). The first case of this injury was reported in 1974 by Cedell (3), who described it as an avulsion mechanism associated with forced dorsiflexion of the pronated foot, where the posterior tibiotalar ligament is torn from its attachment to the talus (7,8). Other mechanisms associated with the incidence of this fracture include direct trauma, inversion force to the foot, and maximum forced plantarflexion of the ankle, with the posterior talar process impinging between the calcaneus and tibia (1,5). Regardless of the
Fig. 4. Computed tomographic scan showing a nonunited fracture of the posteromedial tubercle of the talus.
790
P. Albert et al. / The Journal of Foot & Ankle Surgery 53 (2014) 787–790
fracture fragment is advised to decrease the possibility of subtalar degenerative arthritis (1). Wolf and Heckman (6) reported that the best treatment of a comminuted fracture or symptomatic nonunion of the posteromedial tubercle of the talus was surgical excision of the fracture fragments. Our patient did not meet the criteria for internal surgical fixation, because no displacement of the fracture fragment or subtalar joint involvement was present. However, surgical intervention for removal of the hypertrophic ossicle was recommended, which the patient refused. Successful internal fixation has been reported in published studies for fracture of the posteromedial process of the talus. In a case report by Chen et al (10), the authors showed that ORIF using a screw for a displaced fracture of the medial tubercle of the posterior process of the talus proved effective. After the procedure, their patient used a non-weightbearing splint for 6 weeks, after which the screw was removed (10). The classic approach for ORIF of this fracture type is the posteromedial approach; however, there is an increased risk of damage to the adjacent neurovascular structures. Mendicino et al (11) recommended a method termed the oblique medial malleolar osteotomy approach for the management of medial talar dome lesions. However, the same method can be used for ORIF of the posteromedial tubercle fracture to minimize the likelihood of neurovascular insult. A longitudinal 5- to 7-cm incision is made over the medial malleolus to create an oblique osteotomy angled 45 to the tibial plafond. This technique ensures proper visualization of the posterior talar processes and helps preserve the deltoid ligament (11). Letonoff et al (1) published a case report in which they performed ORIF using the oblique medial malleolar osteotomy approach. They used two 2-0 mm bioabsorbable screws for fixation and found complete healing of the fracture site. However, the patient developed subtalar joint arthritis after 16 months in the postoperative period (1). Few reports have described the use of closed reduction and physical therapy for the treatment of nondisplaced fractures of the posteromedial tubercle of the talus (7,10). In such cases, initial immobilization and non-weightbearing is required, followed by a period of appropriate rehabilitation exercises to ensure optimum results. Nonetheless, closed reduction can be rendered unsuccessful if the FHL tendon is interposed between the fracture fragments, such as reported by Dougall and Ashcroft (12). A case report published in 1996 used immobilization in a patient with a non-weightbearing short leg cast for 7 weeks, and the patient reported no symptoms after that period (8). In another case study, the fracture was diagnosed 4 weeks after the initial injury, and the patient was placed in a fiberglass cast for 2 weeks followed by CAM walker for 4 weeks. The investigators noted progressive osseous union at 6 weeks (5). Kim et al (13) performed a retrospective study of 5 patients with fracture of the posteromedial tubercle of the talus. Of the 5 patients, 2 had been diagnosed acutely, treated with immobilization in a
non-weightbearing cast, and achieved excellent results. The remaining 3 patients were initially misdiagnosed and developed chronic medial ankle pain. They eventually underwent delayed surgical excision of the fracture fragment and reported pain relief comparable to that of the first group (13). For our patient with a chronic nonunited fracture, in whom the fracture had been initially misdiagnosed, the treatment course was not clear. We had to use our clinical judgment and considered the patient’s compliance to treatment. We suggested both surgical and conservative therapy; however, the patient opted out of both. One limitation of our case report was the absence of any therapeutic interventions used to successfully treat the fracture and the absence of follow-up imaging studies to document whether any healing had occurred. In conclusion, fracture of the posteromedial tubercle of the talus is a rare injury. Because this injury is uncommon, it is often misdiagnosed. After our patient had injured his ankle 6 years earlier, he continued to have chronic pain and swelling localized to his right rearfoot and ankle. In cases such as this, in which an accurate diagnosis has finally been made years after the initial injury, crosssectional imaging studies such as MRI and CT can be helpful determine the precise nature of the injury.
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