C Voigt1, C Hurschler, J Althainz, R Vosshenrich, H Lill. 1. Klinik für Unfall- und Wiederherstellungschirurgie, Diakoniekrankenhaus Friederikenstift gGmbH Hannover, Humboldtstr. 5, 30169 Hannover, Deutschland. christine.voigt@friederikenstift.de
Abstract
OBJECTIVE: Can additive fiber cerclage (FC) reduce secondary displacement in unstable 3-part proximal humeral fractures stabilized by angle-stable plates? Is there any effect of different head screw configurations? METHOD: An unstable 3-part fracture model of the humeral head was developed by preserving the rotator cuff in 24 paired, osteoporotic shoulder specimens. 6 pairs were stabilized by PHILOS plates, and 6 others by HSP. Each left shoulder received FC. 4 groups arose (n=6): I) HSP with FC, II) HSP without FC, III) PHILOS plate with FC, and IV) PHILOS plate without FC. 4 physiological load cases were simulated by a robot-assisted shoulder simulator. Using real-time analysis, interfragmentary motion was measured. RESULTS: Matched-pair analysis of the groups with FC vs. those without FC showed no significant differences in motion at gap I (greater tuberosity head) or II (subcapital) in any load case, apart from interior rotation in groups III and IV at gap II; in these, motion was greater without FC. No differences were seen with different head screw configurations in any load cases. CONCLUSIONS: In cases of anatomical reduction and optimally placed implants, FC did not show an additional stabilizing effect in the unstable 3-part fracture model. Different head screw configurations did not influence stability.
OBJECTIVE: Can additive fiber cerclage (FC) reduce secondary displacement in unstable 3-part proximal humeral fractures stabilized by angle-stable plates? Is there any effect of different head screw configurations? METHOD: An unstable 3-part fracture model of the humeral head was developed by preserving the rotator cuff in 24 paired, osteoporotic shoulder specimens. 6 pairs were stabilized by PHILOS plates, and 6 others by HSP. Each left shoulder received FC. 4 groups arose (n=6): I) HSP with FC, II) HSP without FC, III) PHILOS plate with FC, and IV) PHILOS plate without FC. 4 physiological load cases were simulated by a robot-assisted shoulder simulator. Using real-time analysis, interfragmentary motion was measured. RESULTS: Matched-pair analysis of the groups with FC vs. those without FC showed no significant differences in motion at gap I (greater tuberosity head) or II (subcapital) in any load case, apart from interior rotation in groups III and IV at gap II; in these, motion was greater without FC. No differences were seen with different head screw configurations in any load cases. CONCLUSIONS: In cases of anatomical reduction and optimally placed implants, FC did not show an additional stabilizing effect in the unstable 3-part fracture model. Different head screw configurations did not influence stability.