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Precision of targeting device for subtalar screw placement
Michael Betz1, Karl Wieser, Magdalena Vich
1University of Zurich, Department of Orthopaedics, Zurich, Switzerland.
Foot & Ankle International
|June 28, 2012
Summary
A new targeting device for subtalar arthrodesis screw placement did not significantly improve accuracy but did reduce surgeon and patient radiation exposure. This innovation offers a safer alternative for this critical surgical step.
Area of Science:
- Orthopedic Surgery
- Surgical Innovation
- Biomedical Engineering
Background:
- Subtalar arthrodesis requires precise screw placement for stability and bone healing.
- Free-hand screw placement can be time-consuming and involve significant radiation exposure.
- A dedicated targeting device may mitigate these risks.
Purpose of the Study:
- To evaluate the efficacy of a novel targeting device in improving screw placement accuracy during subtalar arthrodesis.
- To assess the impact of the targeting device on intraoperative radiation exposure.
- To compare the targeting device method with the conventional free-hand technique.
Main Methods:
- Twenty matched-pair cadaveric hindfoot specimens were used, fixed with Thiel embalming.
- Specimens were randomized into two groups: targeting device (Group 1) and fluoroscopic control (Group 2).
- Screw placement was performed by an experienced surgeon and a resident; outcomes were assessed radiographically.
Main Results:
- Optimal screw positioning was achieved in 50% of specimens in both groups.
- Suboptimal placement occurred in 40% of cases (4/10 in each group).
- Radiation exposure was significantly lower in the targeting device group (4.1 cGy*cm² vs. 8.1 cGy*cm²; p=0.012).
Conclusions:
- The targeting device did not offer a significant technical advantage in screw placement accuracy.
- The device substantially reduced radiation exposure for both patients and surgeons.
- No neurovascular complications were observed with the targeting device.
