Devices and methods used for shoulder replacement

Abstract

The present invention provides a method and devices for shoulder replacement surgery that spares the rotator cuff. The method utilizes two anterosuperior passages to gain access to the glenohumeral joint, neither of which requires transaction of the rotator cuff. In addition a transhumeral portal created through the second anterosuperior passage for use as a working tunnel. Specialized instruments and implants are provided to work through both the anterosuperior passage as well as the transhumeral portal.

Description

[0001] Applicant claims, under 35 U.S.C §119(e), the benefit of priority of: 1) the filing date of Aug. 11, 2003 of U.S. Provisional Application No. 60 / 494,289, 2) the filing date of Oct. 8, 2003 of U.S. Provisional Application No. 60 / 509,655, 3) the filing date of Oct. 16, 2003 of U.S. Provisional Application No. 60 / 511,805, 4) the filing date of Nov. 19, 2003 of U.S. Provisional Application No. 60 / 523,401, 5) the filing date of Jun. 15, 2004 of U.S. Provisional Application No. 60 / 579,893 and 6) the filing date of Jul. 2, 2004 of U.S. Provisional Application No. 60 / 585,033, the entire contents of each of which are incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to methods, instrumentation, and implants for orthopaedic surgery and, more specifically, to rotator cuff sparing procedures and associated devices for shoulder replacement surgery. [0004] 2. Discussion of Related Art [0005] Orthopaedic surgeo...

AI Technical Summary

Benefits of technology

[0014] One advantage provided by the above mentioned aspect of the present invention is that it allows determination of a central axis in the proximal humerus which allows simple and less invasive perpendicular access to the humeral and glenoid joint surfaces. An additional advantage is it offers a simple and reliable means of restoring the native anatomy and biomechanical relationships, allowing for an improved functional and durable outcome.

[0015] A further advantage is that it spares the rotator cuff tendons and allows for a quicker and more functional recovery

[0017] Another aspect of the present invention provides a glenoid implant. The glenoid implant includes an ingrowth shell, a wear-resistant surface that is removably attached to the ingrowth shell. An advantage is that the ingrowth shell provides novel geometry and superior fixation to the glenoid.

[0018] An additional aspect of the invention regards a transhumeral portal sleeve with a bullet shaped guide that has a central and a peripheral longitudinal cannulation. An advantage is that it safely creates a working portal along the central axis of the proximal humerus.

[0027] In another aspect, a transhumeral burr is provided. The transhumeral burr has a high speed working burr surface and a removably attached shaft.

Problems solved by technology

It requires an extensive exposure that irreversibly damages the rotator cuff and still fails to gain sufficient joint access to properly restore the native anatomic relationships of both the humeral head and glenoid surfaces.

Also, there remain issues with glenoid implant fixation and early loosening.

This can cause excessive traction on the arm which has resulted in injury to the nerves of the brachial plexus (Lynch N M, Cofield R H, Silbert P L, et al.

Additionally, despite the extensive exposure, conventional methods for shoulder replacement surgery still fail to properly restore the native anatomic relationships of the joint surfaces of the shoulder.

This poses great difficulty for the surgeon since the intramedullary axis has an inconsistent relationship to the humeral surface.

The humeral joint surface also possesses a complex anatomy with significant variability which cannot be entirely restored with conventional methods and implants.

The failure to restore the native anatomic relationships and biomechanics to the shoulder joint has proven to result in a significantly lesser functional and durable outcome (Williams G R, et al.

Conventional methods of shoulder replacement surgery also have difficulty gaining access to the glenoid joint surface.

Because the humeral head sits in the way, this is a nearly impossible task with conventional methods.

Despite improved results of conventional methods when both the humerus and glenoid surfaces are replaced, there still remains limitations with regard to glenoid fixation and early glenoid implant loosening (Boileau P, Avidor C, Krishnan S G, et al., “Cemented polyethylene versus uncemented metal-backed glenoid components in total shoulder arthroplasty: a prospective, double-blind, randomized study”, J Shoulder Elbow Surg 2002;11(4):351-9.).

The cemented implant never incorporates with the glenoid bone and with time, the cement-bone interface eventually fails and the implant comes loose.

Conversely, the metal-backed glenoid prosthesis has an unacceptable rate of early loosening, at least 20% in one study.

However, if the metal-backed implant can remain rigidly fixed to the bone for a sufficient period of time, the bone of the glenoid will eventually adhere to the metal-backed surface and long-term studies have revealed little evidence for late clinical loosening in these cases.

Failure of the metal-backed glenoid implant appears to be related to the limitations in achieving sufficiently rigid and durable initial fixation

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