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Ankle Fracture with Unstable Syndesmosis

There are many varieties of ankle fracture that can occur.  Ankle fractures can be classified by the mechanism that caused that fracture, or the number of locations that have fractured, or by the location of the fracture of the fibula (the bone on the outside of the ankle) relative to the ankle joint line.

Perhaps the most important “classification” of ankle fracture to both the doctor and the patient is whether the fracture will need surgical correction or not.

In some fractures, the ligament structures (called the syndesmosis) that hold together the two leg bones (the tibia and the fibula) that form the ankle socket are torn.  Because of a disrupted, unstable syndesmosis, the tibia and fibula are not held together properly, which makes for a very unstable ankle joint that is prone to chronic disability and arthritis – if not repaired.  Thus, in an ankle fracture with an unstable syndesmosis, surgery is typically recommended.

Since ligaments (and the syndesmosis) cannot be directly visualized on radiographs (plain x-ray films), it is fortunate that we can reliably predict when there has been a syndesmosis injury in conjunction with the fracture(s).  Typically, when the fibular (bone on the outside of the ankle) fracture occurs above the ankle joint level, there is an associated syndesmosis injury.  The fibular fracture may be found 1-2cm (0.5-1 inch) above the ankle joint level, or anywhere higher, including all of the way up to just below the knee.  (See area 1 on the x-ray image) Besides the fibular fracture and syndesmosis tear, one might also see that the talus (the bone in the ankle socket that moves up and down) is shifted towards the outside of the ankle.  (See area 2 on the x-ray image)  There may also be a fracture present at the inner knob of the ankle (the medial malleolus of the tibia), (see area 3 on the x-ray image), and/or the back of the tibia (the innermost / big leg bone) at the ankle joint (also called the posterior malleolus).

Open Reduction with Internal Fixation

The name of the surgical procedure for repairing ankle fracture with an unstable syndesmosis is called an open reduction with internal fixation.

During the procedure, your surgeon will restore the original alignment of the fractured bones and hold them in place with surgical hardware, typically:

  • bone screws and a bone plate on the outside bone of the ankle (fibula)
  • bone screws at the inner knob of the ankle (medial malleolus) – if fractured
  • bone screw(s) at the posterior malleolus (back part of the tibia) – if fracture and of sufficient size

The syndesmosis cannot be simply repaired by suturing ligaments together, so instead, the two bones of the leg are stabilized together to allow the syndesmosis to heal in the proper alignment – either by using one or two screws that span the fibula and tibia completely (called syndesmosis screws), or alternatively, by using a device called the tightrope.

The open reduction with internal fixation of an ankle fracture with unstable syndesmosis procedure typically is performed on an outpatient basis.  The anesthesia format is typically spinal or general anesthesia, with a possible regional nerve block.

Before and after surgical correction with typical hardware for a two-part ankle fracture with unstable syndesmosis.  Two “syndesmosis” screws from the fibula to the tibia to stabilize the injured syndesmosis
Before and after surgical correction with typical hardware for a one-part ankle fracture with unstable syndesmosis.  One “syndesmosis” screw from the fibula to the tibia to stabilize the injured syndesmosis.
Before and after surgical correction with typical hardware for a two-part ankle fracture with unstable syndesmosis.  A “tightrope” device was used from the fibula to the tibia to stabilize the injured syndesmosis (note metal buttons on either side and suture path within the tibia).

Goals

The open reduction with internal fixation of an ankle fracture with unstable syndesmosis procedure attempts to provide the following benefits:

  • Restore original bony alignment and stability
  • Reduce the risks associated with the fracture, such as degenerative joint disease (arthritis), chronic pain, and disability
  • Improve the chances of regaining pre-fracture functional status

Risks

As suggested, solely due to the fracture, there are risks of:

  • degenerative joint disease (arthritis)
  • chronic pain
  • stiffness
  • limp
  • loss of function
  • disability
  • chronic swelling
  • failure of bone healing
  • need for ankle brace
  • inability to wear desired footwear

The goal of surgery in this type of injury is to minimize the above risks that inherent to the nature of the fracture.  While those risks can be minimized (or even prevented), with successful surgery, the surgical treatment carries other risks, which include, but are not limited to:

  • infection
  • nerve injury
  • numbness
  • tendon injury
  • prolonged recovery
  • intolerance/breakage/failure of hardware
  • wound or scar problems
  • transfer of pain/arthritis to a new site
  • inability to wear desired footwear
  • loss of toes/foot/limb
  • complex regional pain syndrome (CRPS or RSD)
  • need for additional surgery
  • anesthesia risks
  • blood clots in the leg (deep venous thrombosis)

Alternatives

The alternative to surgery is:

  • non-surgical management with a cast
  • eventual long-term need for an ankle brace

Recovery

This type of open reduction with internal fixation of an ankle fracture procedure typically involves being in a non-removable splint and/or cast for a period of six or more weeks.  Weight bearing status can vary.  The use of crutches or a walker is essential during the non-weight bearing time.  You may elect to rent a knee scooter to assist you with non-weightbearing on the affected foot/ankle.  The knee scooter/caddy is not covered by Kaiser Permanente, but can be rented or purchased from various sources.

The recovery process for this type of open reduction with internal fixation of an ankle fracture is as follows:

  • critical “couch time” (resting most of the day on the couch or in bed with your foot elevated above heart level): 2 weeks
  • weight bearing status: non-weight bearing for 6-8 weeks (this duration may be shortened in some cases, depending on the surgical findings – your surgeon will update you)
  • duration in a non-removable below-knee cast: 6-8 weeks
  • then, duration in a removable walking cast: 1-4 weeks
  • we can determine if you are a good candidate for a ‘water cast’ which you are able to shower with
  • the time needed for off work is dependent on:
    – the type of work that you do (sedentary off feet vs active on feet)
    –  the hours that you work
    –  your ability to drive / get to work
    –  your employer’s policies and capacity to offer modifications of your duties
  • a home physical therapy rehab program will be recommended by your surgeon, and there is typically no need for formal physical therapy appointments
  • your total recovery time (until swelling/tenderness/stiffness have resolved and near-full functional capacity is regained): more than 12 months

The typical appointment timeline for this type of open reduction with internal fixation of an ankle fracture is as follows:

  • Approximately 2 weeks after surgery: cast removal, suture removal, and re-application of a non-removable below-knee cast.
  • Approximately 6-8 weeks after surgery: Cast removal and x-ray check.  Start a removable walking cast.  The process of weaning to shoes and the rehab program to be determined based on your surgeon’s assessment.
  • Approximately 12 weeks after surgery: status check

Your Ankle Hardware

  • Ankle hardware can remain in place permanently.
    –  Typically, 80% or more of our patients never have to have the standard hardware removed
    –  Approximately 20% of our patients may notice hardware prominence that is irritating enough to warrant surgery.  This typically occurs at least 6 months after the initial surgery.

Additional Resources

  • For a great general resource for preparing for foot and ankle surgery and the associated recovery process, please review Preparing for Foot and Ankle Surgery  – developed by the Foot and Ankle Surgery Department at the Kaiser Permanente Medical Center in Santa Rosa.
  • For a great general resource for foot and ankle fractures, please review Foot and Ankle Fractures  – Patient Resources – developed by the Foot and Ankle Surgery Department at the Kaiser Permanente Medical Center in Santa Rosa.