STUDY DESIGN: Experimental design using a laboratory leakage model. OBJECTIVE: To examine that a new aspiration technique, with a double conduit cannula design, improves the uniformity of cement filling, thus significantly reducing the risk of extraosseous leakage. SUMMARY OF BACKGROUND DATA: In vertebral augmentation, understanding the forces governing the intravertebral cement flow is essential for controlling the cement formation. A path of least resistance posed by the irregularities in the bone matrix or vertebral shell increases the risk of leak. We have previously shown that using viscous cement reduces the leakage risk. However, this may damage the already weak bone due to the high forces required for the cement to enter the bone cavities. METHODS: An experimental leakage model for vertebral augmentation was used-with a path, simulating a blood vessel, to provoke leakage. A novel cannula with 2 concentric conduits was used. The inner conduit is used for cement delivery and the outer conduit for aspiration. A mixed level with 2 factors (2 x 2(2)) experiment design was used to examine the ability of aspiration to direct the cement flow in both low and high viscous cement regimes. RESULTS: Aspiration significantly enhanced the filling uniformity and reduced the risk of leakage. The reduction in leak with the suction simultaneous to the injection for low viscosity cement, elapsed time 4 minutes, was 1.5 cc (alpha = 0.05). In the suction experiments, the reduction in leakage as compared with the reference condition for the 8 minutes elapsed time was 0.5 cc, (alpha = 0.05). CONCLUSION: The aspiration technique combined with a new cannula design improved the uniformity of filling. The aspiration technique helps in removal of the displaced bone marrow or tumor tissue. The aspiration applied with the new cannula requires only a single incision. Thus, it does not result in an increased invasiveness.
STUDY DESIGN: Experimental design using a laboratory leakage model. OBJECTIVE: To examine that a new aspiration technique, with a double conduit cannula design, improves the uniformity of cement filling, thus significantly reducing the risk of extraosseous leakage. SUMMARY OF BACKGROUND DATA: In vertebral augmentation, understanding the forces governing the intravertebral cement flow is essential for controlling the cement formation. A path of least resistance posed by the irregularities in the bone matrix or vertebral shell increases the risk of leak. We have previously shown that using viscous cement reduces the leakage risk. However, this may damage the already weak bone due to the high forces required for the cement to enter the bone cavities. METHODS: An experimental leakage model for vertebral augmentation was used-with a path, simulating a blood vessel, to provoke leakage. A novel cannula with 2 concentric conduits was used. The inner conduit is used for cement delivery and the outer conduit for aspiration. A mixed level with 2 factors (2 x 2(2)) experiment design was used to examine the ability of aspiration to direct the cement flow in both low and high viscous cement regimes. RESULTS: Aspiration significantly enhanced the filling uniformity and reduced the risk of leakage. The reduction in leak with the suction simultaneous to the injection for low viscosity cement, elapsed time 4 minutes, was 1.5 cc (alpha = 0.05). In the suction experiments, the reduction in leakage as compared with the reference condition for the 8 minutes elapsed time was 0.5 cc, (alpha = 0.05). CONCLUSION: The aspiration technique combined with a new cannula design improved the uniformity of filling. The aspiration technique helps in removal of the displaced bone marrow or tumor tissue. The aspiration applied with the new cannula requires only a single incision. Thus, it does not result in an increased invasiveness.
Authors: Sven Hoppe; Tarek Elfiky; Marius Johann Baptist Keel; Emin Aghayev; Timo Michael Ecker; Lorin Michael Benneker Journal: Eur Spine J Date: 2015-08-15 Impact factor: 3.134
Authors: Sven Hoppe; Sebastian Wangler; Emin Aghayev; Benjamin Gantenbein; Andreas Boger; Lorin M Benneker Journal: Eur Spine J Date: 2015-04-05 Impact factor: 3.134