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EP-4167909-B1 - INTRAMEDULLARY CANAL SPARING HUMERAL IMPLANT, MANUFACTURING METHOD THEREFOR AND SURGICAL KIT

EP4167909B1EP 4167909 B1EP4167909 B1EP 4167909B1EP-4167909-B1

Inventors

  • ROBICHEAUX, Alysha
  • CHEN, ELLEN

Dates

Publication Date
20260506
Application Date
20210618

Claims (14)

  1. A humeral implant (5300), comprising: a collar (5310); and a central body (5340) extending from a bottom side of the collar, a plurality of fins (5350) extending downward and radially outward from the central body, wherein at least one fin of the plurality of fins extends farther distally than the central body and comprises: an inner bottom edge (5355) extending downward from the central body, wherein a radial distance between the inner bottom edge of the at least one fin and a central axis of the humeral implant increases along a distal length of extension of the at least one fin to, thereby, compact bone of the metaphysis of a humerus toward the central axis when press-fit therein, and a serrated outer bottom edge (5351) extending downward from the central body, wherein a radial distance between the outer bottom edge of the at least one fin and the central axis of the humeral implant decreases along the distal length of extension of the at least one fin until meeting the inner bottom edge at a lowermost tip (5370) of the at least one fin.
  2. The humeral implant of claim 1, wherein each of the plurality of fins extends farther distally than the central body and comprises: an inner bottom edge (5355) extending downward from the central body, wherein a radial distance between the inner bottom edge of each of the plurality of the fins and the central axis of the humeral implant increases along a distal length of extension of each of the plurality of fins, and a serrated outer bottom edge (5351) extending downward from the central body, wherein a radial distance between the outer bottom edge of each of the plurality of fins and the central axis of the humeral implant decreases along the distal length of extension of each of the plurality of fins until meeting the inner bottom edge at lowermost tip (5370) of the fin.
  3. The humeral implant of claim 1, wherein the serrated outer bottom edge of the at least one fin is configured to cut into and compact bone of the metaphysis of the humerus toward relatively denser cancellous bone of a peripheral portion of the humerus when press-fit therein.
  4. The humeral implant of claim 1, wherein the central body has a substantially cylindrical shape that tapers along its length of extension.
  5. The humeral implant of claim 2, wherein the plurality of fins extending farther distally than the central body allows for metaphyseal placement of the humeral implant in a humerus (100) of a patient that avoids humeral canal morphology.
  6. The humeral implant of claim 1, wherein the plurality of fins are equally spaced about the central body.
  7. The humeral implant of any preceding claim, wherein the collar comprises a plurality of windows (5320).
  8. The humeral implant of claim 7, wherein the collar comprises an outer ring and a central portion and the plurality of windows, together, have a substantially circular shape interrupted by portions of the collar coupling the outer ring and the central portion.
  9. The humeral implant of claim 7, wherein the collar has a substantially circular shape.
  10. The humeral implant of any preceding claim, wherein the humeral implant further comprises a porous coating (5360) on at least a portion of the at least one fin.
  11. The humeral implant of claim 10, wherein the porous coating comprises pores of varying sizes, thereby aiding in apposition of bone ingrowth.
  12. The humeral implant of claim 1, wherein implanting of the humeral implant causes the inner bottom edge to compact the bone of the metaphysis of the humerus toward the central axis, thereby increasing a density of the bone surrounding the humeral implant.
  13. A method of manufacturing a humeral implant of any preceding claim, the method comprising: forming a collar (5310); forming a central body (5340) extending from a bottom side of the collar; and forming a plurality of fins (5350) extending downward and radially outward from the central body, such that at least one fin of the plurality of fins extends farther distally than the central body and comprises: an inner bottom edge (5355) extending downward from the central body, wherein a radial distance between an inner bottom edge of the at least one fin and a central axis of the humeral implant increases along a distal length of extension of the at least one fin to, thereby, compact bone of the metaphysis of a humerus toward the central axis when press-fit therein, and a serrated outer bottom edge (5351) extending downward from the central body, wherein a radial distance between the outer bottom edge of the at least one fin and the central axis of the humeral implant decreases along a distal length of extension of the at least one fin until meeting the inner bottom edge at a lowermost tip (5370) of the at least one fin.
  14. A surgical kit for shoulder arthroplasty, the surgical kit comprising a plurality of humera implants according to claims 1-12.

Description

BACKGROUND The present disclosure relates to implants, systems and/or kits for shoulder arthroplasty and associated methods. Shoulder arthroplasty is a surgical procedure, often utilized to treat and/or alleviate chronic pain in arthritic and/or otherwise damaged shoulders, in which a portion of one or both of a humerus and its socket are replaced with implanted components designed to restore some or all of the natural range of motion and stability in the affected shoulder joint. However, implantation (and in some cases revision) of implants can require extensive remodeling and/or alteration of the bones and soft tissues involved, especially the humerus of the upper arm. Accordingly, a need exists for implants, systems and/or kits for shoulder arthroplasty, and associated methods, that allow for sparing of bone while also providing the ability for easy revision surgery. US-A-2010/114326 describes a modular prosthetic implant including a support cleat unit having a circular seat portion and a shape delimited by an imaginary dome. The support cleat unit includes a cylindrical body portion having a central axis and a hole concentric with the central axis, the hole having a least a first section whose diameter defines a female Morse taper adapted to receive a male member having a corresponding Morse taper. The support cleat unit also includes a plurality of arched appendages integral with the cylindrical body portion. The arched appendages are radially spaced apart from one another and extend outwardly from a base portion thereof at an outer circumferential surface of the cylindrical body portion so that lower/outer surfaces of the arched appendages define the overall domed shape of the support cleat unit. US-B-8506638 describes a prosthesis which includes a central body having a longitudinal axis and a plurality of arms extending from the central body in a direction substantially perpendicular to the longitudinal axis. The plurality of arms may each include a first planar surface, a second planar surface, and a third planar surface that are each formed at an obtuse angle relative to one another to define an outer shape of the prosthesis. EP-B-2663263 may be considered as the closest prior art and describes a stemless shoulder prosthesis comprising a fixation device for fixing the prosthesis to a resected humerus bone, the fixation device comprising a base portion and anchoring means, the base portion having a distal side adapted to contact a resection plane of the bone and a proximal side for carrying a humeral head. The anchoring means are connected to the distal side of the base portion and adapted to fix the prosthesis to the bone. The anchoring means define a central axis perpendicular to the distal side of the base portion and a free central space around the central axis. Further, the anchoring means comprise wall sections projecting from the base plate substantially perpendicular to the distal side of the base plate. Each wall section extends between an inner edge and an outer edge. The wall sections have a height measured from the distal side of the base portion , the height of each wall section decreasing from its outer edge towards the inner edge, each wall section having a maximum height at is outer edge and a minimum height at its inner edge. SUMMARY The present invention is defined by claims 1 and 13. A humeral implant is provided. The humeral implant includes a humeral stem comprising a plurality of fins, wherein at least one fin comprises a serrated bottom edge. The terms "humeral stem", "humeral implant" and "humeral stem implant" are used interchangeably throughout the present disclosure and represent the entire implant. In some embodiments, each of the plurality of fins comprises a serrated bottom edge. A radial distance between a medial edge of the at least one fin and a centerline of the humeral implant increases along a distal length of extension of the at least one fin. In some embodiments, at least the serrated bottom edge of the at least one fin is configured to cut into and compact bone of a medial portion of the metaphysis of a humerus toward relatively denser cancellous bone of a peripheral portion of the humerus when press-fit therein, thereby providing sufficient press-fitting for cementless fixation of the humeral stem into the humerus. The humeral implant includes a central body and the plurality of fins extend radially away from the central body. In some embodiments, the central body has a substantially cylindrical shape that tapers slightly along its length of extension. At least a portion of the plurality of fins extends farther distally than central body, thereby allowing for metaphyseal placement of the humeral implant in a humerus of a patient that avoids the humeral canal morphology. The plurality of fins may be equally spaced about the central body. The humeral implant includes a collar, wherein the collar may comprise a plurality of windows and a porous coating configured