DEVICE FOR INSERTION AND FIXATION OF METAL IMPLANT IN SURGICAL MANAGEMENT OF TRAUMATICALLY INJURED PUBIC SYMPHYSIS OF PELVIC RING Russian patent published in 2015 - IPC A61B17/90 

FIELD: medicine.

SUBSTANCE: device for insertion and fixation of a metal implant in surgical management of traumatically injured pubic symphysis of the pelvic ring consists of a parallelepiped-shaped conductor one of narrow front sides of which is concaved with radius R₃ and has round-angled borders skewed at 22°. A lower surface of the conductor has a groove configured as a flat ring segment and limited by arches of two circles with the centre common with that of the concaved front side of the conductor with radius R₃. Radiuses of the two circles - smaller - R₂ and greater - R₁, fit those of a metal implant plate temporary used during the surgical intervention. A groove width equals to that of the metal implant plate. A groove depth makes 0.4 of a thickness of the metal implant plate. At the intersection of a long symmetry plane of the conductor and the mean radius R of the annular groove, there is a through threaded hole with a buried captive screw temporary securing the metal implant plate to the conductor before the surgical intervention. The threaded hole has a cylindrical slot enclosing a screw head flush with an upper surface of the conductor. On the upper surface of the conductor on radius R fitting the mean radius R of the annular groove, there are two cylinders configured integrated with the conductor body and mirror-symmetrical, in relation to the long symmetry plane of the conductor; the cylinders have an external diameter of 14 mm and a height of 28 mm; on their side surfaces, the cylinders have on all height facing flat cuts spaced at 8.5 mm. A distance of the cylinder axes of the conductor equals to that of the axes of the two holes formed on the metal implant plate and used to bury fixing screws used to secure the metal implant plate to the injured pubic symphysis of the pelvic ring during the surgical intervention, and makes 20 mm. Along the axes, the cylinders of the conductor have through holes 9 mm in diameter used to alternately enclose a detachable guide applicable to drill the pubic symphysis of the pelvic ring during the surgical intervention. A through hole diameter of the cylinder fits the external diameter of the guide, and an external diameter of a head of the pelvic fixing screw used to secure the metal implant plate to pubic symphysis of the pelvic ring during the surgical intervention. The other wide front side of the conductor has a round-angled rectangular to attach and secure a parallelepiped-shaped onlay to the conductor; the parallelepiped-shaped onlay comprises a round-angled rectangular through hole shaped the same as the rectangular projection on the wide front side of the conductor. In the centre of the rectangular projection of the conductor, there is a through threaded hole to secure the onlay to the conductor manually by means of a wide-head screw. On the opposite side of the onlay, there are two through holes of the same diameter mirror-symmetrical, in relation to the long symmetry plane of the onlay and applicable to enclose alternately a removable trocar with a tubular guide and insert locking retainers in the pubic symphysis during the surgical intervention. A distance of the through hole axes of the onlay equals to that of the axes of the two holes formed on the metal implant plate and used to bury the fixing screws used to secure the metal implant plate to the injured pubic symphysis of the pelvic ring during the surgical intervention, and makes 20 mm. An onlay length is specified so that a distance from an inner surface of the annular ring of the conductor to a horizontal plane passing through the axes of the two mirror-symmetrical holes of the onlay equals to a length of the pelvic fixing screws used during the surgical intervention.

EFFECT: reliable anatomical restoration of the shape and support function of the pelvis, adequate recurrence-free fixation of the pubic symphysis, prevented multiple-plane displacements of the secured bones and achieved anatomically correct fusion of the pubic symphysis.

5 cl, 5 dwg