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US6022377A Expired / Lapsed US ⏱️ 0.0 years remaining

Instrument for evaluating balance of knee joint

Assignee: Zimmer Inc
•
Filing: 1998-01-20
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Granted: 2000-02-08
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Expires: 2018-01-20
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Abstract

Abstract A knee joint balancing instrument. A first body includes a first paddle for engaging a proximal end of a tibial bone. A second body includes a second paddle for engaging a distal end of a femoral bone. A rack is attached to the first body and is moveable relative thereto in a superior-inferior direction. The second body is pivotally mounted to the rack for pivoting about an axis extending in an anterior-posterior direction. A ratchet is connected to the first body and to the rack for selectively restraining movement of the rack in the superior-inferior direction relative to the first body. A pinion is connected to the first body and engages the rack to cause movement of the rack in the superior-inferior direction relative to the first body. Tension can be induced in the medial and lateral soft tissues of the knee joint by moving the rack, the tension being evenly distributed between the medial and lateral condyles of the knee joint by the pivot mounting of the second paddle, such that an imbalanced response of the medial and lateral soft tissues to a balanced tensile load is indicated.

Inventors

  • 👤 Douglas G. Nuelle
  • 👤 Mark B. Lester
  • 👤 Mark E. Milburn
  • 👤 Erroll Sweat
  • 👤 Stuart Weikel

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 13:29
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/02; A61B17/025; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/46; A61F2/4657; A61B2017/0268; A61B17/28; A61B17/2812; A61B17/2833; A61B2017/2837; A61B90/00; A61B90/06; A61B2090/061; A61B2090/067; A61F2/38; A61F2/3859; A61F2/389; A61F2002/4658; A61F2002/4666; A61F2002/4667

Claims Analysis

Total Claims: 34
Claim 1
Independent Claim 168 words
A knee joint balancing instrument comprising: a rack; a first body movably mounted on the rack and including a first paddle for engaging one of a proximal end of a tibial bone and a distal end of a femoral bone; a second body pivotally mounted on the rack and including a second paddle for engaging the other of said proximal end of said tibial bone and said distal end of said femoral bone; means interconnecting said rack and said first body for moving the first paddle in a superior-inferior direction relative to the second paddle; means interconnecting said rack and said second body for pivoting said second paddle from a level position to a tilted position about an axis extending in an anterior-posterior direction; said second body being resiliently mounted to automatically return to the level position from the tilted position; and ratchet means connected to said first body and said rack for selectively restraining movement of said rack in the superior-inferior direction relative to said first body.
Claim 2
Dependent Claim 168 words
A knee joint balancing instrument comprising: a rack; a first body movably mounted on the rack and including a first paddle for engaging one of a proximal end of a tibial bone and a distal end of a femoral bone; a second body pivotally mounted on the rack and including a second paddle for engaging the other of said proximal end of said tibial bone and said distal end of said femoral bone; means interconnecting said rack and said first body for moving the first paddle in a superior-inferior direction relative to the second paddle; means interconnecting said rack and said second body for pivoting said second paddle from a level position to a tilted position about an axis extending in an anterior-posterior direction; said second body being resiliently mounted to automatically return to the level position from the tilted position; and ratchet means connected to said first body and said rack for selectively restraining movement of said rack in the superior-inferior direction relative to said first body.
Claim 3
Dependent Claim 41 words
The knee joint balancing instrument of claim 1, in which said second paddle is anatomically shaped including a medial portion for engaging a medial condyle and a lateral portion for engaging a lateral condyle of said proximal end of said bone.
Claim 4
Dependent Claim 26 words
The knee joint balancing instrument of claim 2, in which said pivot axis is disposed intermediate said medial portion and said lateral portion of said paddle.
Claim 5
Dependent Claim 24 words
The knee joint balancing instrument of claim 3, in which said second paddle includes a posterior notch providing clearance for a posterior cruciate ligament.
Claim 6
Dependent Claim 41 words
The knee joint balancing instrument of claim 3, in which said first paddle is anatomically shaped including a medial portion for engaging a medial condyle and a lateral portion for engaging a lateral condyle of said proximal end of said bone.
Claim 7
Dependent Claim 24 words
The knee joint balancing instrument of claim 5, in which said first paddle includes a posterior notch providing clearance for a posterior cruciate ligament.
Claim 8
Dependent Claim 28 words
The knee joint balancing instrument of claim 1 wherein said means for moving said first paddle includes a pinion connected to said first body and engaging said rack.
Claim 9
Dependent Claim 20 words
The knee joint balancing instrument of claim 7, and further including torque driving means removably engagable with said pinion means.
Claim 10
Dependent Claim 31 words
The knee joint balancing instrument of claim 7, and further including indicator means connected to said first body and to said second body for indicating angular displacement of the knee joint.
Claim 11
Dependent Claim 116 words
The knee joint balancing instrument of claim 9, in which said second paddle includes a medial portion for engaging a medial condyle and a lateral portion for engaging a lateral condyle of said proximal end of said bone, said pivot axis being disposed intermediate said medial portion and said lateral portion of said paddle; whereby tension can be induced in the medial and lateral soft tissues of the knee joint by moving said rack, said tension being evenly distributed between the medial and lateral condyles of the knee joint by said pivot mounting of said second paddle, such that an imbalanced response of the medial and lateral soft tissues to a balanced tensile load is indicated.
Claim 12
Dependent Claim 20 words
The knee joint balancing instrument as defined in claim 1 wherein the first body includes a first handle extending therefrom.
Claim 13
Dependent Claim 23 words
The knee joint balancing instrument as defined in claim 1 wherein the first body includes a bore formed therethrough for receiving the rack.
Claim 14
Dependent Claim 24 words
The knee joint balancing instrument as defined in claim 1 wherein the first body includes a plurality of mounting pin receiving holes formed therein.
Claim 15
Dependent Claim 21 words
The knee joint balancing instrument as defined in claim 1 wherein the first body includes alignment tool receiving bores formed thereon.
Claim 16
Dependent Claim 30 words
The knee joint balancing instrument as defined in claim 1 wherein said ratchet means includes ratchet teeth formed on said rack and a pawl pivotally attached to said first body.
Claim 17
Dependent Claim 23 words
The knee joint balancing instrument as defined in claim 7 wherein said rack includes rack gear teeth formed thereon for engaging said pinion.
Claim 18
Dependent Claim 33 words
The knee joint balancing instrument as defined in claim 11 wherein said body includes a resilient member engaging said rack for biasing said second body to the level position relative to said rack.
Claim 19
Dependent Claim 19 words
The knee joint balancing instrument as defined in claim 17 wherein said second body includes an angle reference member.
Claim 20
Dependent Claim 19 words
The knee joint balancing instrument as defined in claim 18 wherein said angle reference member includes an index thereon.
Claim 21
Dependent Claim 30 words
The knee joint balancing instrument as defined in claim 19 wherein said rack includes a second handle extending therefrom and an indicator member mounted thereon and extending adjacent the index.
Claim 22
Dependent Claim 97 words
An instrument for tensioning and balancing a knee joint comprising: a main support; a first member mounted on the main support and including a first paddle; a second member pivotally mounted on the main support and including a second paddle and an angle reference member thereon; a drive device interconnecting the first member and the main support for positionably adjusting the first member toward and away from the second member; and a spring rod interconnecting the second member and the main support for biasing the second paddle to a neutral position relative to the angle reference member.
Claim 23
Dependent Claim 97 words
An instrument for tensioning and balancing a knee joint comprising: a main support; a first member mounted on the main support and including a first paddle; a second member pivotally mounted on the main support and including a second paddle and an angle reference member thereon; a drive device interconnecting the first member and the main support for positionably adjusting the first member toward and away from the second member; and a spring rod interconnecting the second member and the main support for biasing the second paddle to a neutral position relative to the angle reference member.
Claim 24
Dependent Claim 27 words
The instrument as defined in claim 21 wherein the first member includes a first handle extending therefrom and the main support includes a second handle extending therefrom.
Claim 25
Dependent Claim 18 words
The instrument as defined in claim 21 wherein the first member includes mounting pin receiving holes formed therein.
Claim 26
Dependent Claim 18 words
The instrument as defined in claim 21 wherein the first member includes alignment tool receiving holes formed therein.
Claim 27
Dependent Claim 24 words
The instrument as defined in claim 21 wherein the main support includes ratchet teeth for engagement with a pawl mounted on the first member.
Claim 28
Dependent Claim 25 words
The instrument as defined in claim 21 wherein the drive device is a pinion mounted on the first member for engagement with the main support.
Claim 29
Dependent Claim 22 words
The instrument as defined in claim 21 wherein the main support includes an indicator member extending therefrom adjacent the angle reference member.
Claim 30
Dependent Claim 21 words
The instrument as defined in claim 26 wherein the main support includes rack gear teeth formed thereon for engaging said pinion.
Claim 31
Dependent Claim 16 words
The instrument as defined in claim 27 wherein said angle reference member includes an index thereon.
Claim 32
Dependent Claim 136 words
An instrument for tensioning and evaluating balance for a knee joint comprising: a main support; a first member adjustably mounted on the main support and including a first paddle extending in a lateral orientation relative to the main support; a second member mounted on the main support and including a second paddle and an angle reference member thereon, the second paddle extending in lateral orientation relative to the main support substantially parallel to the first member and pivotally movable to an angular position from the lateral orientation; a drive device interconnecting the first member and the main support for positionably adjusting the first member toward and away from the second member; and a spring rod interconnecting the second member and the main support for biasing the second paddle from the angular position to the lateral orientation.
Claim 33
Dependent Claim 136 words
An instrument for tensioning and evaluating balance for a knee joint comprising: a main support; a first member adjustably mounted on the main support and including a first paddle extending in a lateral orientation relative to the main support; a second member mounted on the main support and including a second paddle and an angle reference member thereon, the second paddle extending in lateral orientation relative to the main support substantially parallel to the first member and pivotally movable to an angular position from the lateral orientation; a drive device interconnecting the first member and the main support for positionably adjusting the first member toward and away from the second member; and a spring rod interconnecting the second member and the main support for biasing the second paddle from the angular position to the lateral orientation.
Claim 34
Dependent Claim 35 words
The instrument as defined in claim 30 wherein the main support includes an indicator member extending from a first end thereof adjacent the angle reference member, and a handle extending from a second end thereof.

References Cited (Backward Citations)

US5468244A Cited
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US5540696A Cited
US5735904A Cited
US5800438A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2003-02-07 2003-08-09 2004-02-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2007-02-07 2007-08-09 2008-02-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2011-02-07 2011-08-09 2012-02-08 $7700.00 Window Closed / Lapsed

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