Locking cap release mechanism
AssigneeDePuy Synthes Products, Inc.
InventorHenry Rutledge
Life of this patent
Estimating the term…
Abstract
The present invention is directed to a release mechanism for removing and/or releasing a locking cap from the head of a bone anchor in situ. The release mechanism includes a sleeve, an anchor coupling member and a knob. The anchor coupling member is located within the sleeve and the knob engages both the anchor coupling member and the sleeve. The distal end of the sleeve and anchor coupling member engage the bone anchor causing the bone anchor to splay from the locking cap. A driver may be inserted into the central bore of the release mechanism to release any further threaded engagement of the locking cap and the bone anchor.
Claims20
A release mechanism for releasing a locking cap threadingly engaged with a bone anchor head, the release mechanism including:
- a sleeve comprising:
- a sleeve bore extending along a longitudinal axis of the sleeve;
- a distal end of the sleeve sized and configured to surround at least a portion of the locking cap and the bone anchor head, the distal end including a saddle portion, the saddle portion configured to abut a rod retained between the locking cap and the bone anchor head;
- an anchor coupling member including:
- a body portion having a proximal end that releasably mates with a knob, the body portion including an inner bore extending along a longitudinal axis of the anchor coupling member;
- at least two arms extending from the body portion, each of the arms sized and configured to cover at least respective portions of the locking cap and the bone anchor head, each of the arms including a coupling feature at a distal end sized and configured to matingly engage a corresponding coupling feature of the bone anchor head;
- the knob including:
- a handle;
- a knob body;
- a knob bore extending through the handle and knob body along a longitudinal axis of the knob, the knob bore including a mating portion for releasably mating the knob with the anchor coupling member;
- wherein the sleeve bore is sized and configured to receive at least a portion of the anchor coupling member and a portion of the knob body.
A method of releasing a locking cap attached to a bone anchor, the method comprising:
- assembling a release mechanism including:
- inserting a portion of an anchor coupling member into a bore in a release sleeve;
- aligning a side of a sleeve saddle portion with a side of a coupling feature of the anchor coupling member, where the sleeve saddle portion extends from a distal end of the release sleeve and the coupling feature extends from a distal end of the anchor coupling member;
- attaching a knob to the anchor coupling member by inserting a portion of the knob into the release sleeve such that an inner bore of the knob matingly engages with the anchor coupling member;
- attaching the coupling feature to a corresponding coupling feature on the bone anchor such that the sleeve saddle portion impacts a rod retained between the locking cap and the bone anchor and the coupling feature splays a side of the bone anchor from the locking cap.
Dependencies are inferred from the claim text.