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Fibula Nail for Unstable Ankle Fractures

Paul Appleton Trauma SurgeonPaul Appleton, MD is an Orthopedic Trauma surgeon in the Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, and Instructor in Orthopedic Surgery at Harvard Medical School.


Ankle fractures are becoming more common injuries, particularly among elderly females. The incidence rate of ankle fractures has increased from 65/100,000 in 1950 to 100-122/100,000 in 2002. The treatment of choice for unstable ankle fractures in the young is open reduction and internal fixation. Studies have shown higher functional outcome and satisfaction following surgical intervention, however complication rates can be as high as 40 percent in high risk patients.(1)

There have been several reports published about the different methods of fixing unstable ankle fractures – including standard plates and screws, rush rods and fibula nails. While each of these methods has proven successful in the younger population, the results are less satisfactory in patients over 60 years of age.(1)

There is also a significant re-operation rate due to painful and/or prominent metal work over the lateral malleolus. Brown et. al reported a 23% incidence of hardware-related pain requiring implant removal.(1)

There are several possible difficulties one may encounter when operating on an elderly person: osteoporotic fractures, higher incidence of wound complications, loss of fixation, and both prominent and painful metal work. Thus, the use of a fibula nail is appealing because it affords stable fixation with minimal surgical exposure and less prominent metal work.

The indications for the use of the fibula nail include any displaced ankle fracture that involves the lateral malleolus. We typically do not use it for higher Weber C-type fractures as these are typically treated with syndesmotic screws alone. One must use caution in trimalleolar fractures involving a large posterior fragment as these patterns tend to do better with direct open posterior plating. In these latter cases, a standard 1/3 tubular plate is used, as the surgical approach to the fibula has already been performed.(2)

Surgical Technique
A 0.5-1.0 cm incision is made just distal to the tip of the fibula (Figure 1). Blunt dissection may be carried out with a small schnidt to avoid injuring the peroneal tendons. A 1.2 mm K-wire is then inserted into the distal fibula just at the tip and in the midline. It is important to check a lateral view to ensure the entry point is not too anterior or posterior. A cannulated drill is then passed over the K-wire to open the canal approximately 2 cm in length.

Figure 1. A lateral view of a distal fibula with an outline of the fibula showing the recommended placement of the incision.
Trauma Rounds Lateral view of a distal fibular Recommended placement of skin incision

Reduction techniques
Percutaneous reduction clamps may be placed around the fracture to hold it reduced prior to reaming and placing the nail (Figure 2). Once the fracture is reasonably reduced, the fibula canal is reamed with a 3.1 mm hand reamer.

Figure 2: Percutaneous reduction clamps are placed around the fracture to hold reduction.
Trauma Rounds Percutaneous Reduction Clamps placed around fracture

Figure 3: Final films showing placements of the nail and screws.
Trauma Rounds Placement of Nails and screws

Fixation
The fibula nail is now inserted using the percutaneous insertion guide. One or two anterior to posterior screws are placed through the nail. Fibula length can be assessed intra-operatively using the C-arm and assessing the talocrural angle. If the fibula appears shortened, longitudinal traction can then be placed on the guide and a blocking screw placed at the proximal tip of the nail to maintain length.

Alternatively, once length has been established a syndesmotic screw may be placed through the nail, both to maintain length and stabilize the syndesmosis. A temporary large pointed reduction clamp is used to hold the syndesmosis reduced prior to instrumentation. Stress views are routinely taken intra-operatively to assess the location of the syndesmosis.

Complications
A fibula nail inserted percutaneously has a lower complication rate when compared with formal open reduction and internal fixation using standard AO techniques. In a series by Bugler et al. there were no wound complications in this former group.2 Comparatively, there was a 16% complication rate in the open reduction group. Similar series have confirmed these low rates, including wound infection complications and the need for hardware removal due to pain.(2)

The fibula nail provides a relatively easy technique for treating displaced ankle fractures. We found a high success rate with its use, especially in our elderly population.1 This technique affords the opportunity to provide fixation through a minimal approach with a limited incision, which decreases the chances of wound infection. Further, the intra-medullary fixation eliminates the need for hardware removal from the lateral malleolus due to prominent metal work. We still had difficulty in maintaining a reduction on the medial side in several patients, but in all cases these were elderly patients with suboptimal bone quality.

Summary
The fibula nail is probably the ideal choice for fixing ankle fractures in the elderly patients or those with overlying skin conditions, or co-morbidities such as diabetes and steroid use, in which there are higher infection rates with traditional plating techniques. We found a low complication rate and little difficulty with its use intra-operatively.

References
1. Appleton P, McQueen M, Court-Brown C. The fibula nail for treatment of ankle fractures in elderly and high risk patients. Tech Foot Ankle, 5:204–208 (2006).
2. Bugler KE, et al. The treatment of unstable fractures of the ankle using the Acumed fibular nail. Development of a Technique. J Bone Joint Surg Br, 94-B: 1107-1111 (2012).

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