SLR - February 2013 - Kwan
Reference: Mauffrey, C., Bailey, J.R., Hak, D.J., and Hammerberg, M.E. (2012). Patient Safety in Surgery, 6(6), online publication.
Scientific Literature Review
Reviewed by: Jessica Kwan, DPM
Residency Program: St. John Hospital & Medical Center, Detroit MI
Podiatric Relevance:
The surgical approach to manage calcaneal fractures poses a challenge for the podiatric profession. Currently, open reduction with internal fixation is the most common method of surgically addressing calcaneal fractures, but there is a high rate of wound dehiscence and infection. The authors of this article describe a less invasive method to percutaneously fixate intra-articular calcaneal fractures using an inflatable bone tamp.
Methods:
Preoperative planning using computerized tomography is essential for this technique. First, fracture lines and the position of the depressed articular fragment need to be identified in order to determine screw placement and the path over which the inflatable bone tamp will be positioned through a cannula to obtain anatomical reduction.
The patient is placed in a prone position. A three centimeter curvilinear posterolateral calcaneal skin incision is made, and a guide wire used to determine an entry point for the cannula. The cannula is inserted through the proximal cortex and a drill bit used so the cannula lies beneath the articular fragment. Fluoroscopy is used to confirm adequate position of the tip of the cannula in relation to the depressed articular fragment. Three two-millimeter K-wires are inserted beneath the cannula to create a rafting support for balloon inflation, and the balloon is inserted through the cannula. The balloon is inflated using radiopaque dye. Usually an inflation pressure of 250ppi is sufficient to elevate the articular fragment. The volume of the dye used is recorded, as this amount will be replaced with bone substitute. Lateral and Harris views are then taken using fluoroscopy to assess reduction of the fracture fragment.
The articular fragment is then temporarily stabilized with a K-wire, after which the balloon is deflated and the cannula removed. The void left by the balloon expansion is filled with liquid calcium phosphate, which is allowed to harden. One or two 7.3 mm partially threaded cannulated screws are used for permanent fixation. Incision site closure is performed and the patient is placed in a posterior splint. Once sutures are removed two weeks postoperatively, the patient is placed in a postoperative boot and remains non-weight-bearing for a total of 10 weeks.
Results:
The authors were able to percutaneously fixate calcaneal fractures with a successful radiographic outcome utilizing this technique. However, they have no long-term data on functional outcome or long-term advantages of this technique and will publish them in the future. A possible complication of the procedure is if the balloon bursts during the reduction maneuver. The bone void should be irrigated with normal saline and the balloon should be reinserted. Another complication is if the balloon does not inflate evenly and the articular fragment does not elevate. There is also a risk that the calcium phosphate injected into the bone void can potentially extravasate into the subtalar joint.
Conclusions:
Patient selection is important when implementing this technique, as is preoperative planning. The ideal fracture to fixate using this technique is one with a large depressed articular fragment.