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A 27-year-old female with right ankle pain
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A 27-year-old otherwise healthy woman was evaluated 1 month after she sustained an isolated right-ankle fracture dislocation in a sky diving accident. The patient was initially treated at another institution, where she underwent open reduction and internal fixation (ORIF) with syndesmotic screw fixation in the OR. Initial injury films were unavailable. Imaging revealed a non-anatomic ankle mortise at her 1-month follow-up visit, and she was subsequently referred to our clinic.
A CT scan of the coronal cut of the right ankle is shown.
A CT scan of the sagittal cut of the right ankle is shown.
A CT scan of the axial cut of the right ankle is shown.
Images: Kwon JY
When the patient was initially evaluated in our clinic, she ambulated with crutches and reported 0/10 right ankle pain at rest, with pain increasing to 3/10 following activity. Physical examination revealed well-healed surgical scars, minimal swelling and no signs of infection. She had limited right tibiotalar and subtalar motion. She was neurovascularly intact distally. Non-weight-bearing radiographs and subsequent CT imaging of the right ankle demonstrated a non-anatomic ankle mortise with a displaced posterior malleolar fracture with an intra-articular fragment blocking reduction (Figures 1, 2 and 3).
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Right trimalleolar equivalent ankle fracture, malreduction and retained deep metal implants
Following a syndesmotic injury, anatomic reduction and restoration of the syndesmosis and ankle mortise are significant predictors of functional outcome. Anatomic reduction of the fibula fracture is required prior to properly reduce the syndesmosis. However, accurate syndesmotic reduction can be difficult, with studies reporting a 16% to 52% postoperative malreduction in both open- and closed-reduction cases. While open reduction may lead to more accurate reduction, Miller and her colleagues reported up to 16% of cases have persistent malreduction on postoperative CT scans. Syndesmotic fixation is employed to stabilize distal tibiofibular alignment while disrupted ligaments heal. Traditional transsyndesmotic screw fixation has been considered the gold standard for years, yet technique, number of screws, screw size and necessity of screw removal continued to be disputed. Furthermore, other devices, such as suture buttons, offer an alternative approach to syndesmotic stabilization.
Complications
The literature has demonstrated increased rates of syndesmotic malreduction and poor outcomes when intraoperative clamping and fixation are performed. Miller and her colleagues evaluated syndesmotic reduction with clamps placed at varying angles from the fibula, followed by screw placement. Clamps placed at 15° and 30° from the fibula significantly displaced the fibula in external rotation, causing over-compression of the syndesmosis. Clamp and screw placement was found to impact the orientation of the fibula during reduction and cause over-compression of the syndesmosis.
Suture-button fixation of the syndesmosis is a dynamic alternative mode of fixation. The theoretical advantage of the suture button is to allow for more physiologic micro-motion while maintaining anatomic reduction. The fibula is pulled into the incisura fibularis, a natural concavity. In a cadaver study that compared suture-button fixation to screw fixation in 48 malreduced syndesmosis, Westermann and his colleagues showed suture-button fixation resulted in less syndesmotic malreduction. In addition, results from cadaver studies that compared the strength of screw constructs to suture-button fixation were comparable (73% to 89%).
Another cause of malreduction is the failure to recognize interposed bony fragments or soft tissue. Open reduction better allows examination of the fracture site to assess for interposed fragments or soft tissue.
Treatment
The patient was taken to the OR for removal of hardware and revision ORIF. First, by utilizing the same incision from the index procedure, previously implanted screws were removed. A standard posterolateral approach was taken with the interval between the peroneal tendons and the flexor hallucis longus developed in order to remove the interposed fragment of bone. We sharply transected the posterior syndesmosis which was transected in order to book open the posterior malleolar fragment and remove the interposed fragment. The posterior malleolus was anatomically reduced and affixed using a 4-mm partially threaded cannulated screw (Arthrex) with a washer. Next, a separate incision over the fibula fracture was made to access the fracture site. After remobilization and anatomic reduction, a one-third tubular plate was placed with multiple 3.5-mm cortical screws placed proximally, including an apex screw to gain length.
Attention was turned to the syndesmosis, which appeared relatively anatomic. In a standard technique using the previous percutaneous stab incision, a 3.5-mm cortical screw was placed across four cortices in the distal hole of the plate with the foot in inversion. Clamping of the syndesmosis was not performed due to a relatively high rate of malreduction using this technique. A suture-button device was placed completing the ORIF of the distal tibiofibular joint. Final intraoperative fluoroscopy films demonstrated an anatomic mortise.
Radiographs were obtained 6 weeks postoperatively (Figure 4). A discussion took place with the patient regarding the risks and benefits of removal of the syndesmotic screw. She agreed with the plan and underwent subsequent removal of the syndesmotic screw 3 months after the revision procedure.
At her follow-up appointment 4 months after the removal of the syndesmotic screw, she was doing well clinically and returned to full activities of daily living. She was also running with minimal discomfort, and radiographs demonstrated a healed ankle fracture with an anatomic mortise (Figures 5 and 6).
Commentary
Multiple biomechanical studies have examined the rigidity of suture-button devices as compared to metal screws for stabilization of the syndesmosis and have demonstrated equivalency. However, there is a role for screw fixation, suture-button fixation and/or the use of both implants depending on a case-by-case basis.
In our opinion, the use of metal screws and/or a combination of screw and suture button devices for revision cases is recommended. Often in revision cases, the syndesmosis remains slightly wide, with insufficient tibiofibular overlap on intraoperative radiographs, despite adequate debridement. In such cases, anatomic alignment can be achieved by placing a cortical screw in lag fashion, which affords further compression. A suture-button device can then be added for additional stabilization, especially if syndesmotic screw removal is anticipated. Conversely, the suture-button device can be placed prior to screw placement in order to increase the likelihood of obtaining anatomic reduction as recent literature has demonstrated less malreduction of the syndesmosis as compared to metal screws.
- References:
- Gardner MJ, et al. Foot Ankle Int. 2006;27(10):788-792.
- Manjoo A, et al. J Orthop Trauma. 2010;doi:10.1097/BOT.0b013e3181a9f7a5.
- Miller AN, et al. Foot Ankle Int. 2009;doi:10.3113/FAI.2009.0419.
- Miller AN, et al. J Orthop Trauma. 2013;doi:10.1097/BOT.0b013e31825197cb.
- Pelton K, et al. Foot Ankle Int. 2010;doi:10.3113/FAI.2010.0604.
- Porter DA. Instr Course Lect. 2009;58:575-581.
- Seitz WH, et al. J Orthop Trauma. 1991;5(1):78-82.
- Soin SP, et al. Foot Ankle Int. 2009;doi:10.3113/FAI.2009.0346.
- Weening B, et al. J Orthop Trauma. 2005;19(2):102-108.
- Westermann RW, et al. J Bone Joint Surg Am. 2014;doi:10.2106/JBJS.N.00198.
- For more information:
- Adam Roy, BA, can be reached at Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111; email: adam.roy@tufts.edu.
- Catherine A. Logan, MD, MBA, MSPT, is a PGY-5 resident in the Harvard Combined Orthopaedic Residency Program and can be reached at Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114; email: calogan@partners.org.
- John Y. Kwon, MD, is the chief of the Division of Foot and Ankle Surgery, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center and can be reached at 330 Brookline Ave., Boston, MA 02115; email: jykwon@bidmc.harvard.edu.
Disclosures: Roy, Logan and Kwon report no relevant financial disclosures.