METHOD AND APPARATUS FOR DETERMINING ACETABULAR COMPONENT POSITIONING

• US 20130018430A1
• Filed: 09/17/2012
• Published: 01/17/2013
• Est. Priority Date: 11/01/2007
• Status: Active Grant

• Current Assignee: M.D. Stephen B. Murphy
• Original Assignee: M.D. Stephen B. Murphy
• Inventors: Murphy, Stephen B.
• Granted Patent: US 10,299,807 B2
• Time in Patent Office: Days
• US Class Current: 606/86.R
• CPC Class Codes: A61B 17/00 Surgical instruments, devices or methods, e.g. tourniquets A61B18/00 takes precedence; contraceptive devices, pessaries, or applicators therefor A61F6/00; eye surgery A61F9/007; ear surgery A61F11/00
• CPC Class Codes: A61B 17/17 Guides or aligning means for drills , mills, pins or wires
• CPC Class Codes: A61B 17/1746 for the acetabulum
• CPC Class Codes: A61B 17/56 Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2090/067 for measuring angles
• CPC Class Codes: A61B 2090/364 Correlation of different images or relation of image positions in respect to the body
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 5/107 Measuring physical dimensions, e.g. size of the entire body or parts thereof
• CPC Class Codes: A61B 5/1071 measuring angles, e.g. using goniometers A61B5/1123 takes precedence
• CPC Class Codes: A61B 5/1072 measuring distances on the body, e.g. measuring length, height or thickness A61B5/1076 takes precedence
• CPC Class Codes: A61B 5/1114 Tracking parts of the body
• CPC Class Codes: A61B 90/06 Measuring instruments not otherwise provided for
• CPC Class Codes: A61B 90/11 with guides for needles or instruments, e.g. arcuate slides or ball joints
• CPC Class Codes: A61F 2/4609 of acetabular cups
• CPC Class Codes: A61K 2300/00 Mixtures or combinations of active ingredients, wherein at least one active ingredient is fully defined in groups A61K31/00 - A61K41/00
• CPC Class Codes: A61K 31/409 having four such rings, e.g. porphine derivatives, bilirubin, biliverdine hemin, hematin A61K31/555
• CPC Class Codes: A61K 31/44 Non condensed pyridines; Hydrogenated derivatives thereof
• CPC Class Codes: A61K 31/555 containing heavy metals, e.g. hemin, hematin, melarsoprol
• CPC Class Codes: A61K 45/06 Mixtures of active ingredients without chemical characterisation, e.g. antiphlogistics and cardiaca
• CPC Class Codes: B43L 7/10 : Plural straightedges relatively movable
• CPC Class Codes: F16C 11/10 : Arrangements for locking
• CPC Class Codes: F16C 11/103 : frictionally clamped
• CPC Class Codes: F16C 2316/10 : in medical appliances, e.g. in diagnosis, dentistry, instruments, prostheses, medical imaging appliances
• CPC Class Codes: G01B 3/56 : Gauges for measuring angles or tapers, e.g. conical calipers
• CPC Class Codes: G01B 3/563 : Protractors for use in geodesy G01C1/00; protractor heads for drawing machines B43L13/08
• CPC Class Codes: G01B 5/24 : for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: Y10T 403/32426 : Plural distinct positions

Abstract

An instrument for establishing orientation of a pelvic prosthesis comprises a tripod having an angularly adjustable guide rod on it. The tips of the legs define a plane, and the guide rod is set by the surgeon to a defined orientation with respect to this plane on the basis of preoperative studies. In use, two of the legs of the instrument are positioned by the surgeon at defined anatomical locations on the pelvis (e.g., a point in the region of the posterior/inferior acetabulum and a point on the anterior superior iliac spine). The third leg then lands on the pelvis at a point determined by the position of the first two points, as well as by the separations between the third leg and the other two legs. The position of the guide rod then defines with respect to the actual pelvis the direction for insertion of a prosthesis.

Claims

1. An instrument establishing a reference plane for a human body structure, comprising:

first and second arms emanating from a common hub and angularly separated from each other, each arm having a first arm segment affixed to said hub and a second arm segment extensible with respect to said first arm segment;

first, second and third connectors for connecting first, second and third legs to said first and second arms, respectively, and to said hub;

a direction indicator movably connected to said instrument for indicating a direction in space; and

an angular indicator for indicating the angular orientation of said direction indicator relative to said instrument.

2. An instrument according to claim 1 in which said angular indicator comprises first and second angular scales for measuring angles in differing planes to indicate the orientation of said direction indicator with respect to said instrument.

3. An instrument according to claim 1 in which said angular indicator comprises a first angular scale for indicating the orientation of said direction indicator in a first plane and a second angular scale for indicating the orientation of said direction indicator in a second plane perpendicular to said first plane.

4. An instrument according to claim 3 in which said first plane comprises a plane formed by said first and second arms.

5. An instrument according to claim 4 in which said angular scales are mounted on said instrument for movement relative to each other.

6. An instrument according to claim 3 in which one of said angular scales is fixed to said instrument and the second of said angular scales is mounted for rotation with respect thereto.

7. An instrument according to claim 6 in which said direction indicator is pivotally mounted on said second angular scale.

8. An instrument according to claim 1 in which said angular indicator comprises a first angular scale mounted on said instrument for measuring orientation in a plane defined by said first and second arms and a second angular scale mounted for rotation in said plane with respect to said first angular scale for measuring angular orientation in a plane perpendicular to said first plane.

9. An instrument according to claim 8 in which said direction indicator is pivotally mounted on said second angular scale.

10. An instrument according to claim 1 in which at least one of said arm segments of each arm has a scale thereon for indicating the degree of extension of the respective arms.

11. An instrument establishing a reference plane for a human body structure, comprising:

first and second arms emanating from a common hub and angularly separated from each other, each arm having a first arm segment affixed to said hub and a second s arm segment extensible with respect to said first arm segment;

first, second and third legs for connection to said first and second arms, respectively, and to said hub;

a direction indicator movably connected to said instrument for indicating a direction in space; and

an angular indicator for indicating the angular orientation of said direction indicator relative to said instrument.

12. An instrument according to claim 11 in which said legs have pointed tips for secure lodgment on a human body structure.

13. An instrument according to claim 12 in which said legs are formed to extend fixed distances from a plane defined by said first and second arms, the tips of said legs defining reference plane for defining the orientation of the instrument when placed on a human body structure.

14. An instrument according to claim 12 in which said legs are of equal length.

15. An instrument according to claim 12 in which at least one of said legs is shorter than the others.

16. An instrument according to claim 12 in which at least one of said legs is hollow to accommodate a rod affixable to the body structure to facilitate placement of the instrument on the body structure.