[The role of capsuloligamentotaxis and minimally invasive percutaneous osteosynthesis with rigid and dynamic unilateral external fixation of the intra-articular pilon fracture]

Fractures of the tibial pilon are severe injuries which can be accompanied by articular impaction, comminution and soft tissue injury. Soft tissue injury with already existing skin damage can further complicate the method of treatment. In these cases, the method of unilateral or circular external fixation can be used as an alternative method of treatment. Minimally invasive percutaneous osteosynthesis with spanning rigid and dynamic unilateral external fixation as a one-stage method has been used for the treatment of intra-articular pilon fractures. We report a case of a patient with an intra-articular pilon fracture with chronic venous insufficiency and venous ulcer, who was injured after falling from a height and who had emergency surgery based on capsuloligamentotaxis and percutaneous osteosynthesis with a spanning unilateral external fixator. The patient was mobilized postoperatively for walking without weight bearing on the injured leg. The initial rigid spanning external fixation was transformed into dynamic fixation to enable ankle joint movements 8 weeks after surgery. The external fixator was removed 4.5 months after surgery and the Kirschner wire and screws were removed 7 months after surgery. The final functional result 1 year after the injury was good and motion of upper ankle joint was moderately restricted without pain. Swelling occurred after walking for longer distances.

Identifying safe corridors for anterior pelvic percutaneous instrumentation using computed tomography-based anatomical relationships

INTRODUCTION

Percutaneous anterior pelvic ring instrumentation is performed for retrograde screw fixation of ramus fractures, as well as for repair of pubic symphysis diastasis. The anatomic relationships of critical structures around the anterior pelvic ring, such as the spermatic cord and round ligament, have been described in only a few studies regarding the risk of iatrogenic injury during surgery. Our goal is to further describe these relationships, as well as provide radiographic information on safe corridors for percutaneous fixation.

METHODS

Eighty (80) axial computed tomography scans of the abdomen, obtained for non traumatic diagnostic purposes and screened for prior abdominal trauma or procedures, were evaluated by 3 fellowship trained radiologists. Mid-symphyseal cuts were used to obtain several measurements relative to the spermatic cords (SC) or round ligaments (RL): inter-cord or inter-ligament distance, skin to cortex of symphysis distance (vertical), skin to cortex of symphysis distance (oblique), safe corridor distance (between SC/RL and femoral triangle), center safe angle (relative to bilateral ischia), maximal safe angle, and minimal safe angle.

RESULTS

There were 41 male and 39 female scans included in the final analysis. The average inter-cord distance was 50.2 mm, skin to cortex vertical distance of 43.0 mm, skin to cortex oblique distance of 83.5 mm, safe corridor distance 26.3 mm, center safe angle 19.3˚, maximal safe angle 32.3˚, and minimal safe angle 13.6˚. These were further broken down by range and gender in Table 1. Agreement between radiologists was high for these different measurements with the exception of the skin to cortex oblique distance in female patients and the maximal safe angle in female patients, due to absence of round ligament in a majority of the scans. The round ligament was only present at the mid-symphyseal level for our three reviewers in 37/39, 36/39, and 24/39 of female patient scans.

CONCLUSIONS

We have identified defined safe corridors for instrumentation of the anterior pelvic ring that can assist the surgeon in percutaneous application of fixation for fracture care.