Screw with anchor features

摘要

Screws for anchoring in cancellous or other low-quality bone are described. One type of screw addresses the problem of extravazation of bone cement when filling an area of low-quality bone. The screw includes an expandable container for retaining bone cement and anchoring the screw in low-quality bone. The screw also includes an anchoring device for holding the screw in place in the bone while it is supplied with bone cement or other appropriate filler. The screw further includes a head for connecting to a rod or other apparatus. A second type of screw uses an expandable container to deform two or more fins to compress cancellous bone and/or anchor in cancellous bone.

主权项

1. A screw for anchoring in cancellous bone, the screw comprising:
a screw head comprising a receiver, a distal end, and a proximal end, wherein the proximal end is configured as a channel; an anchoring device connected to the distal end of the screw head; an expandable container; a delivery adapter, the delivery adapter comprising:
a body comprising a proximal end and a distal end;a connector attached to the distal end of the body, wherein the connector is configured to be removably attached to the receiver of the screw head,wherein the connector comprises a lumen port and an interface filler port that coaxially surrounds the lumen port; anda filler arm connected to the body; and an inner lumen extending through the expandable container, wherein the inner lumen forms an opening at a distal most end of the screw, wherein the lumen port of the connector is configured to interface with the inner lumen of the screw and the interface filler port connects to filler space around the inner lumen of the screw.