Renew compression screw

• US 20060069393A1
• Filed: 10/14/2005
• Published: 03/30/2006
• Est. Priority Date: 08/22/2000
• Status: Active Grant

• Current Assignee: Dror Paley, LLC
• Original Assignee: Kartikeya P. Pathak
• Inventors: Pathak, Kartikeya P.
• Granted Patent: US 7,666,212 B2
• Time in Patent Office: Days
• US Class Current: 606/304
• CPC Class Codes: A61B 17/60 for external osteosynthesis, e.g. distractors, contractors
• CPC Class Codes: A61B 17/8605 Heads, i.e. proximal ends projecting from bone
• CPC Class Codes: A61B 17/8625 Shanks, i.e. parts contacting bone tissue

Abstract

An external fixator implant screw with an intercalated head, of which one embodiment for lag screw mode has a spherical head, and a partial thread. The spherical head in countersunk bone exerts concentric wide contact on insertion at various angles to surface. Optional canalization of central rod allows guide wire technique and optional mobility of head allows variable shaft length between head and thread. Another embodiment for use in basic implant mode, in a single bone fragment, at right angles to bone surface, has a conical head with limited basal contact on bone, the head being integrated to a solid rod and is fully threaded from head to leading tip. In both embodiments, the load transmission is renewable from outside in case of loosening, without reopening any wound. The implant is made of biocompatible material.

Claims

1. A basic mode solid rod external fixator half-pin implant for driving at right angles to bone surface for controlling a single fragment;

comprising,

a first end for driving in bone, with a thread at first end; and

a second end for securing to external fixator by clamps, with a grip for turning at second end;

an intercalated fixed conical head with base towards the first end, having a blunt serrated margin for limited contact on bone surface;

the implant device, being fully threaded from first end to intercalated head for wide load bearing, and having an extended rod length from head to the second end for driving, and for securing it to external construct and to renew the stability on loosening.

2. A lag mode external fixator implant intended for compressing two fracture surfaces, at right angles to fracture plane for best compression, and for insertion at varying angles to outer bone surface, comprising;

a first end for driving in bone, with a thread at first end; and

a second end for securing to external fixator through clamps, with a grip at second end for turning;

an intercalated fixed spherical head for broad contact at countersink in bone surface, at different angles of insertion; and

the implant being partially threaded from first end, thread stopping short of the intercalated head, and having a smooth shaft between the thread and spherical head for gliding through fragments nearer to the head, engaging the bone thread in only one fragment near the first end, having an extended rod length from head to the second end for driving, also for securing it to an external fixator construct and for renewing compression after loosening.

3. The device of claim 2 wherein the entire rod is canalized from first end for second end throughout, for passing a guide wire through any one end and out the other.

4. The device of claim 2 comprising a mobile intercalated head capable of re-fixation at different levels between the thread and the second end by means of a transverse screw through head and rod;

transverse holes being present in the extended rod at intervals, in a linear distribution.

5. The device of claim 2 comprising a mobile intercalated head capable of re-fixation at different levels between the thread and the second end by means of a transverse screw through head and rod;

in which the transverse holes in the rod are situated at intervals, in a spiral distribution.

6. The device of claim 2 wherein the rod is canalized from first end to second end throughout for passing a guide wire through any end and out the other, and having a mobile head capable of re-fixation by means of a transverse screw at different levels to a linear series of holes in the rod.

7. The device of claim 2 wherein the rod is canalized from first end to second end throughout for passing a guide-wire through any end and out the other, and having a mobile intercalated head re-fixable to rod by transverse screw through any of the holes distributed along the rod in a spiral distribution.