US-20260124046-A1 - Offset Adjustable Neck Length Trial Device and System for Hip Arthroplasty

US20260124046A1US 20260124046 A1US20260124046 A1US 20260124046A1US-20260124046-A1

Abstract

Improved hip arthroplasty trial devices and hip arthroplasty trial systems are described. A hip arthroplasty trial device has a head member having a central axis and defining an inner chamber, a head member opening providing access to the inner chamber, and a cavity extending inward from the outer surface of the head member. A rotatable member is disposed in the inner chamber and along an axis between the central axis and one side of the head member. The cavity extends along an axis between the central axis and another, opposite side of the head member. A spacer is disposed within the head member opening and is moveable between a spacer first position and a spacer second position. Rotational movement of the rotatable member moves the spacer from the spacer first position to the spacer second position.

Inventors

Stephen Patrick Morrisey
Robert James Jones

Assignees

Stephen Patrick Morrisey

Dates

Publication Date: 20260507
Application Date: 20251229

Claims (20)

1 . A hip arthroplasty trial system, comprising: a hip arthroplasty trial device, comprising a head member having a central axis, defining an inner chamber, and having a head member outer surface defining a cavity, a head member distal side, and a head member proximal side defining a head member opening that provides access to the inner chamber; a spacer disposed within the head member opening and moveable between a spacer first position and a spacer second position; and a rotatable member disposed in the inner chamber and along an axis between the central axis and the head member distal side, the rotatable member defining a rotatable member gear and a cam contacting the spacer, the rotatable member gear defining a first set of gear teeth; and a driver comprising an elongate member having a handle, a main body extending from the handle, and a driver gear disposed on the main body and axially spaced from the handle, the driver gear defining a second set of gear teeth sized and configured to mesh with the first set of gear teeth.
2 . The hip arthroplasty trial system of claim 1 , wherein the main body of the driver has a longitudinal axis; and wherein the driver further comprises a terminal projection extending from the main body along the longitudinal axis and beyond the driver gear such that the driver gear is positioned on the longitudinal axis between the terminal projection and the handle.
3 . The hip arthroplasty trial system of claim 2 , wherein the head member cavity has a base wall defining a base wall opening.
4 . The hip arthroplasty trial system of claim 3 , wherein the terminal projection is sized and configured to be received by the base wall opening.
5 . The hip arthroplasty trial system of claim 4 , wherein the driver further comprises a projection extending away from and orthogonal to the longitudinal axis of the main body.
6 . The hip arthroplasty trial system of claim 5 , wherein the projection is disposed between the handle and the driver gear.
7 . The hip arthroplasty trial device of claim 1 , wherein the head member comprises separable first and second head member portions.
8 . The hip arthroplasty trial device of claim 7 , wherein the first head member portion defines a post; and wherein the second head member portion defines a recess sized and configured to receive the post.
9 . The hip arthroplasty trial device of claim 1 , wherein the main body of the driver defines a taper.
10 . A hip arthroplasty trial system, comprising: a hip arthroplasty trial device, comprising a head member having a central axis, a spacer moveable between a spacer first position and a spacer second position relative to the head member, and a rotatable member disposed in the head member and along an axis parallel to the central axis, the rotatable member defining a first gear and a cam contacting the spacer; a driver comprising a second gear configured to mesh with the first gear such that rotation of the driver results in rotation of the rotatable member and movement of the spacer from the spacer first position to the spacer second position.
11 . The hip arthroplasty trial system of claim 10 , wherein the head member defines a cavity sized and configured to receive the second gear.
12 . The hip arthroplasty trial system of claim 11 , wherein the cavity has a base wall defining a base wall opening.
13 . The hip arthroplasty trial system of claim 12 , wherein the driver further comprises a terminal projection sized and configured to be received by the base wall opening.
14 . The hip arthroplasty trial system of claim 13 , wherein the driver further comprises a projection extending away from and orthogonal to a longitudinal axis of the driver.
15 . The hip arthroplasty trial system of claim 14 , wherein the second gear is disposed between the projection and the terminal projection.
16 . The hip arthroplasty trial device of claim 10 , wherein the head member comprises separable first and second head member portions.
17 . The hip arthroplasty trial device of claim 16 , wherein the first head member portion defines a post; and wherein the second head member portion defines a recess sized and configured to receive the post.
18 . The hip arthroplasty trial device of claim 10 , wherein the main body of the driver defines a taper.
19 . A hip arthroplasty trial system, comprising: a hip arthroplasty trial device, comprising a head member having a central axis, a spacer moveable between a spacer first position and a spacer second position relative to the head member, and a rotatable member disposed in the head member and defining a cam contacting the spacer and a first gear extending circumferentially around a first non-central axis of the head member; and a driver comprising a second gear extending circumferentially around a second non-central axis of the head member and configured to releasably mesh with the first gear such that rotation of the driver results in rotation of the rotatable member and movement of the spacer from the spacer first position to the spacer second position.
20 . The hip arthroplasty trial system of claim 19 , wherein the head member defines a cavity sized and configured to receive the second gear.

Description

RELATED APPLICATION This application is a continuation of U.S. application Ser. No. 18/760,916, filed on Jul. 1, 2024 and issued as U.S. Pat. No. 12,514,718, which is a continuation of U.S. application Ser. No. 17/733,355, filed on Apr. 29, 2022 and issued as U.S. Pat. No. 12,023,261, which claims the benefit of U.S. Provisional Application No. 63/181,493, filed on Apr. 29, 2021. The disclosure of each of these related applications is hereby incorporated into this disclosure in its entirety. FIELD The disclosure relates to the field of medical devices. More particularly, the disclosure relates to hip arthroplasty trial devices and hip arthroplasty trial systems. BACKGROUND When implanting a femoral head during a hip arthroplasty procedure, surgeons currently utilize multiple head length options, which must be individually trialed, to determine the desired offset between the femoral head and a femoral stem. Each trial requires assembly and disassembly of the different head lengths to determine whether a desired offset has been achieved, which results in the hip being dislocated and relocated numerous times during the trial procedure. This multiple trial approach to determining a desired offset between a femoral head implant and a femoral stem has significant drawbacks, such as being complex, time consuming, and disrupting tissue. Hip arthroplasty is a challenging and complex procedure that often provides limited space for maneuvering and manipulating components. Changing trial devices requires undesirable movement of multiple trial devices into and out of this environment. Even manipulating existing adjustable trial devices can present a challenge considering the limited space available during the procedure. A need exists, therefore, for new and improved hip arthroplasty trial devices and hip arthroplasty trial systems. BRIEF SUMMARY OF SELECTED EXAMPLES Various hip arthroplasty trial devices and hip arthroplasty trial systems are described herein. An example hip arthroplasty trial device comprises a head member, a spacer disposed in and movable within an opening defined by the head member, a rotatable member defining a gear and a cam adapted to translate the spacer upon rotation of the rotatable member, a drive gear having teeth that mesh with teeth of the gear defined by the rotatable member, and a locking member. Another example hip arthroplasty trial device comprises a head member, a spacer disposed in and movable within an opening defined by the head member, a rotatable member defining a gear and a cam adapted to translate the spacer upon rotation of the rotatable member, a drive gear having teeth that mesh with teeth of the gear defined by the rotatable member, and a locking member. The drive gear is positioned between a central longitudinal axis of the head member and a proximal side of the head member, which defines the opening within which the spacer is disposed. The gear defined by the rotatable member is positioned between the central longitudinal axis of the head member and a distal side of the head member. Another example hip arthroplasty trial device comprises a head member, a spacer, a rotatable member, a drive gear, an o-ring disposed on the spacer, and a locking member. The rotatable member defines a cam adapted to translate the spacer upon rotation of the rotatable member. The head member comprises separable first and second head member portions. The rotatable member defines first and second bosses the seat in corresponding grooves of the first and second head member portions, respectively. The first boss defines a gear having teeth that mesh with teeth of the gear defined by the rotatable member. The second boss defines a series of pockets that receive projections defined by the locking member. The drive gear is positioned between a central longitudinal axis of the head member and a proximal side of the head member, which defines the opening within which the spacer is disposed. The gear defined by the rotatable member is positioned between the central longitudinal axis of the head member and a distal side of the head member. Another example hip arthroplasty trial device comprises a head member, a spacer disposed in and movable within an opening defined by the head member, a rotatable member defining a gear and a cam adapted to translate the spacer upon rotation of the rotatable member, and a locking member. The head member defines a cavity providing access to the gear defined by the rotatable member. Another example hip arthroplasty trial device comprises a head member, a spacer disposed in and movable within an opening defined by the head member, a rotatable member defining a gear and a cam adapted to translate the spacer upon rotation of the rotatable member, and a locking member. The head member defines a cavity providing access to the gear defined by the rotatable member. The cavity is positioned between a central longitudinal axis of the head member and a proximal side of the head mem