Cranial flap fixation device

Abstract

A cranial flap fixation device utilizing a piece design comprising an inner member and an outer member. The inner member includes a head and a shaft and the outer member comprises a nut for securing onto the shaft. A driving tool may be engaged with the inner member for secure engagement with the outer member. The present invention is also a cranial flap fixation system comprising three pieces, a nut, a bolt and a lock washer. The bolt having a threaded portion head for receipt into the nut and lock washer assembly, and the bolt also having an extra wide head portion for secure engagement inside the patient's cranium. The bolt is designed for use with a variety of bone structures since it is designed having an adjustable length so that the surgeon can cut the bolt after tightening onto the nut and lock washer assembly. A driving tool may be utilized to secure the cranial flap fixation system.

1  (Canceled).  
     
     
         2 : A cranial flap fixation device, comprising: 
 a resorbable inner member dimensioned to be placed between a person's skull and brain, and including a head having a diameter and a shaft extending from the head, the shaft having a diameter less than the diameter of the head; and    a resorbable outer member dimensioned to be placed over a person's skull, the resorbable outer member including an upper convex surface, a lower concave surface, and an aperture extending from the upper convex surface to the lower concave surface, the aperture being sized to accommodate the shaft of the resorbable inner member therethrough, and the lower concave surface being relatively smooth and devoid of protrusions.    
     
     
         3 : The cranial flap fixation device as set forth in  claim 2 , wherein the lower concave surface is devoid of any collars or ridges surrounding the aperture.  
     
     
         4 : The cranial flap fixation device as set forth in  claim 2 , wherein a thickness of the resorbable outer member near the aperture does not substantially exceed an average thickness of the resorbable outer member.  
     
     
         5 : The cranial flap fixation device as set forth in  claim 2 , wherein a thickness of the resorbable outer member, measured adjacent to the aperture between the upper convex surface and the lower concave surface, is not substantially greater than any other thickness of any portion of the resorbable outer member that is not adjacent to the aperture.  
     
     
         6 : The cranial flap fixation device as set forth in  claim 2 , the resorbable outer member further comprising an engagement structure to engage a driving tool.  
     
     
         7 : The cranial flap fixation device as set forth in  claim 6 , wherein the aperture is a first aperture, and wherein the engagement structure comprises a second aperture extending from the upper convex surface to the lower concave surface.  
     
     
         8 : The cranial flap fixation device as set forth in  claim 6 , wherein the resorbable outer member comprises a periphery, and wherein the engagement structure comprises a perforation in the periphery.  
     
     
         9 : The cranial flap fixation device as set forth in  claim 2 , wherein the resorbable outer member is devoid of a radial cutout.  
     
     
         10 : The cranial flap fixation device as set forth in  claim 2 , the resorbable outer member having a non-circular periphery.  
     
     
         11 : The cranial flap fixation device as set forth in  claim 10 , the periphery comprising at least one perforation that renders the periphery uneven.  
     
     
         12 : The cranial flap fixation device as set forth in  claim 2 , wherein at least one of the resorbable inner member and the resorbable outer member include at least one cell-permeable hole for facilitating bone growth.