How Do You Fix Your Syndesmotic Injuries? Can I Use a TightRope Now?
Jaymes D.
Granata,
MD
Terrence M.
Philbin,
DO
The diagnosis and management of ankle syndesmotic injuries have been the topic of much debate in recent years. As a key secondary stabilizer of the ankle joint (second to the deltoid ligament), the syndesmosis plays an integral role in ankle mechanics. Composed of the anterior inferior tibiofibular ligament, posterior inferior tibiofibular ligament, transverse ligament, and interosseous membrane, the syndesmosis secures the distal fibula into the incisura and provides lateral stability to the ankle mortise. Unstable injuries lead to diastasis between the distal tibia and fibula with a subsequent alteration of normal ankle motion.
Syndesmotic injuries occur both in isolation (high ankle sprain) or along with ankle fractures. Traditional teaching has associated these injuries with Weber C ankle fractures, but one should consider the possibility of a syndesmotic disruption in other fracture patterns as well. A recent clinical study reported a 39% incidence of syndesmotic instability in Weber B ankle fractures.1
There are a variety of fixation techniques described for stabilization of the syndesmosis, including screws (traditional and bioabsorbable), staples, thin wire fixators, Kirschner wires, syndesmotic hooks, and cerclage wires. Screw fixation is the most popular technique. The advantages of screw fixation include familiarity of use, low cost, and widespread availability. However, the syndesmosis is dynamic and allows for a certain degree of motion, so one disadvantage of screws is the rigid fixation that they provide. This overconstraint may lead to screw loosening, pullout, and breakage. Some surgeons also advocate routine screw removal, adding the potential morbidity of an additional surgical procedure.
The imperfections of screw fixation have led to the development of alternative dynamic fixation techniques, including the TightRope (Arthrex, Inc, Naples, FL). The TightRope is composed of a #5 FiberWire loop and 2 buttons. The device is tensioned to hold the syndesmotic reduction while allowing more physiologic movement at the distal tibiofibular joint. Proposed advantages of this technique include the elimination of a secondary procedure to remove the implant and earlier mobilization without the concern of screw failure.
We generally use either screw or TightRope fixation to treat ankle syndesmotic injuries. Our decision is based on a number of factors, including patient age, weight, activity level, and time from injury. We have found the TightRope to be useful in both isolated soft tissue injuries as well as ankle fractures with syndesmotic diastasis. There have been reports of TightRope failure in highly unstable fracture patterns, including Maisonneuve-type fractures. If a TightRope is to be used in these situations, we recommend using 2 TightRopes 1 cm apart in a divergent pattern to increase the stability of the construct (Figures 43-1 through 43-3). For diabetics, obese patients, and those with poor bone quality, we typically resort to rigid internal fixation with screws.
Figure 43-1. Injury films demonstrating a Weber C ankle fracture with disruption of the syndesmosis.
Figure 43-2. Highly unstable injury pattern with a widened medial joint space.
Figure 43-3. Open reduction and internal fixation of the fibula with syndesmotic fixation using 2 TightRopes.
Our TightRope postoperative protocol includes 6 weeks of nonweight bearing in a splint/cast, followed by weight bearing as tolerated in a fracture boot. Ankle range of motion exercises are encouraged by week 3. Once full weight bearing is achieved in the fracture boot, patients are progressed to an athletic shoe with an ankle brace. When we use screw fixation, we follow a similar protocol, but the initial nonweight bearing is continued for a total of 10 weeks.
Favorable clinical outcomes have been reported using the TightRope for syndesmotic fixation.2,3 As with any surgical implant or procedure, there are potential complications of which the surgeon and patient should be aware. We have seen 2 complications specific to TightRope fixation, including a fracture of the lateral cortex of the fibula in one patient and skin irritation with local inflammatory reactions in multiple patients.
After the TightRope is tensioned, there is a stress riser at the button-bone interface due to the small surface area of the button. To better distribute the tensioning stress, we now routinely place the TightRope through a plate in both isolated ligament injuries and ankle fractures.
The local inflammatory response and skin irritation is likely due to a combination of factors, including knot prominence and the composition of the suture material itself. The FiberWire suture is coated with silicone and has been associated with a foreign body reaction in some cases, especially when placed in areas of high friction.4 We recommend leaving a small tail after cutting the FiberWire suture and laying it flat to reduce the prominence of the knot.
Regardless of the type of fixation used, anatomic reduction and stable fixation is the key to achieving the best long-term outcome. It is important to be meticulous with your reduction. Malreduction rates have been reported as high as 52% using postoperative computed tomography scans.5 Patients who have malreduced syndesmotic joints generally have a worse outcome due to persistent pain, instability, and ankle arthrosis.
The TightRope technique is a viable option with its own set of potential risks and benefits. No one fixation method has been found to be far superior to all the rest, and the ultimate decision for fixation of syndesmotic injuries depends on surgeon preference and familiarity.
References
1. Stark E, Tornetta P, Creevey WR. Syndesmotic instability in Weber B ankle fractures: a clinical evaluation.
J Orthop Trauma. 2007;21(9):643-646.
2. Cottom JM, Hyer CF, Philbin TM, Berlet GC. Treatment of syndesmotic disruptions with the Arthrex TightRope: a report of 25 cases. Foot Ankle Int. 2008;29:773-780.
3. Thornes B, Shannon F, Guiney AM, Hession P, Masterson E. Suture-button syndesmosis fixation: accelerated rehabilitation and improved outcomes. Clin Orthop Rel Res. 2005;431:207-212.
4. Mack AW, Freedman BA, Shawen SB, et al. Wound complications following the use of FiberWire in lower extremity traumatic amputations. A case series. J Bone Joint Surg Am. 2009;91:680-685.
5. Gardner MJ, Demetrakopoulos D, Briggs SM, Helfet DL, Lorich DG. Malreduction of the tibiofibular syndesmosis in ankle fractures. Foot Ankle Int. 2006;27:788-792.