Arthroscopic shoulder arthroplasty and method thereof
A novel method and instrumentation for insertion of humeral and glenoid total shoulder implant using arthroscopic visualization for bony preparation as well as insertion of components through small incisions. Mini instruments and cannulated guides and reamers are used in order to perform the procedure under direct arthroscopic visualization. For ease of insertion, the components are inserted separately and assembled in situ. Securing the humeral components in place is accomplished with bicortical screw transfixing the central peg of component.
1. A set of components configured for arthroscopically resecting a humeral head and glenoid fossa of a shoulder joint and replacing it with an implant, the set of components comprising:
a stemless humeral head component affixable to a cylindrical metallic portion having a metallic tapered peg having a threaded recess, and a transverse hole;
a glenoid component comprising a base plate and an articular insert;
one or more cannulated shafts;
a first outrigger having ends, and a hole for receiving a guide wire;
a second outrigger having a hole for alignment with the transverse hole in the cylindrical metallic portion;
a central recess boring reamer;
a mechanical center locating device configured to be positioned against a flat surface of the humerus, the device comprising two claws attached to a spring which urges the claws together, and an attachment channel configured to be removably affixed to an end of the first outrigger;
a cannulated sliding sleeve containing a threaded compression rod which has an end engageable with the threaded recess of the metallic tapered peg, the cannulated sliding sleeve removably affixable to the second outrigger.
2. The set of claim 1 , wherein the stemless humeral component further comprises a hemispherical articular bearing surface having a flat back surface in its periphery and a central recess.
3. The set of claim 2 , wherein the stemless humeral head component comprises a cylindrical metallic portion with flat surface at one end to be introduced into said a hemispherical articular bearing surface and a metallic tapered peg at the opposite end, wherein said metallic tapered peg extending laterally away from said flat surface, wherein said metallic tapered peg has a thin circular flange between said cylindrical and the tapered segments.
4. The set of claim 3 , wherein the transverse hole is a cylindrical transverse hole for receiving a locking cortical screw.
5. The set of claim 3 , wherein the hemispherical articular bearing surface is adapted to interlock with the flat portion of the metallic tapered peg.
6. The set of claim 3 , wherein said central recess boring reamer is attached to a rotating shaft driven from a power unit for reaming a central recess for receiving said metallic tapered peg of the humeral head component.
7. The set of claim 2 , wherein the articular bearing surface is constructed from a material selected from the group consisting of: ceramic, metal, metallic alloy and a composite plastic.
8. The set of claim 1 , wherein said mechanical center locating device is configured to locate the center of a flat humeral cut surface.
9. The set of claim 1 , which further comprises one or more reciprocating mini saw blades having a flat plate oriented in the cutting plane of the said reciprocating mini saw blade.
10. A set of claim 1 ,
wherein the metallic tapered peg includes a thin circular flange between the cylindrical metallic portion and the metallic tapered peg portion,
further wherein; the set comprises a compression knob engageable with the threaded rod at an end of the cannulated sliding sleeve.
11. The set of claim 1 , wherein:
the base plate of the glenoid component includes
a circumferential rim and central peg and two holes configured for insertion of large cancellous fixation screws, and,
an articular surface comprising a shallow cavity configured for articulation with the stemless humeral head, wherein said articular insert is seated into and locked into the base plate.