INFLUENCE OF THE SUTURING METHOD ON THE M ECHANICAL-BEHAVIOR OF THE AUGMENTED MACINTOSH ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

The anterior cruciate ligament reconstruction by a biological graft au gmented by a synthetic device allows theoretically to increase the str ength of the composite graft during the remodeling period. The technic al realization of the reinforcement is still controversial because it is difficult to obtain a mechanical compromise between a real effect o f protection of the graft and a load sharing to favour the remodeling. When the graft and the augmentation device are tied together the liga ture between them plays a fundamental mechanical role. The first goal of the present study was to define by calculation and experimentation the influence of the suturing method on the strength of the graft-devi ce ligature. The second goal was to appreciate the possibility of usin g absorbable suture in such an application. Calculation allowed to sho w that the weakest area of the composite graft was the junction betwee n the augmented and unaugmented parts of the graft. When increasing nu mber and anchorage of sutures in this critical area it was possible to double the resistance of the ligature. To define the outcome of absor bable suture the strength decrease was measured during the resorption period. Two threads were tested : the polyglactin 910 (Vicryl) and the polydioxanon (PDS). The strength decrease was sudden and rapid for th e Vicryl (50 p. cent in 3 weeks). For the PDS the strength loss was mo re gradual (50 p. cent in 8 weeks). With these two threads the strengt h duration appeared as incompetent to allow the augmentation to protec t the graft during all the remodeling period.