Skull clamp with load distribution indicators

• US 7,229,451 B2
• Filed: 10/17/2003
• Issued: 06/12/2007
• Est. Priority Date: 04/17/2001
• Status: Expired due to Term

• Current Assignee: Integra Lifesciences Corporation (Integra LifeSciences Holdings Corporation)
• Original Assignee: Integra Companies Incorporated
• Inventors: Lincoln, Donald A., Day, James L.
• Primary Examiner(s): Nguyen; Anhtuan T.
• Assistant Examiner(s): SAM, CHARLES H
• Application Number:
  US10/687,857
• Publication Number:
  US 20040097985A1
• Time in Patent Office: 1,334 Days
• Field of Search: 606/130
• US Class Current: 606/130
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 90/14 Fixators for body parts, e.g. skull clamps; Constructional details of fixators, e.g. pins

Abstract

A three-pin skull clamp [10] includes a C-shaped frame [12] which partially encircles the head [18] of the patient, with a spring-loaded single skull pin assembly [22] located at one end of the frame [12] and adapted to engage the head [18] of the patient with a desired engagement force, and two spaced skull pins [30] mounted to a rocker arm [44] located at an opposite end of the frame [12]. Each of the rocker arm skull pins [30] resides in operative contact with an indicator cap [66] held by a spring-loaded pin carrier assembly [50], the indicator cap [66] being movable relative to the rest of the pin carrier assembly [50] in response to the engagement force applied to the corresponding skull pin [30] by the head [18] of the patient. By visibly comparing the positions of the indicator caps [66] relative to their respective pin carrier assemblies [50], one can readily determine whether the engagement forces are equally distributed between the two rocker arm skull pins [30]. If the indicator caps [66] show significantly unequal load distribution, the rocker arm [44] can be pivotally adjusted to produce a rocker arm orientation which results in a more equal load distribution on the two spaced rocker arm skull pins [30].

Claims

1. A skull clamp for rigidly holding the skull of the patient during surgery comprising:

a C-shaped frame to partially encircle the head of the patient, the frame having first and second ends adapted to be located on opposite sides of the skull of the patient;

a pin assembly located at a first end of the frame and oriented in alignment with an axis which, when in use, extends through the head of the patient and through the second leg of the C-shaped frame, said assembly holding a single skull pin and being adjustable relative to the first end of the frame to enable an operator to selectively determine the force applied to the skull of the patient by the corresponding single skull pin;

a rocker arm located at a second end of the frame, the first and second ends of the frame being aligined along an axis bisecting the skull of the patient and the rocker arm being rotatable relative to the axis; and

a pair of spaced skull pins mounted in a spaced relation on the rocker arm and adapted to engage and hold the skull of the patient opposite the single skull pin, each of said pair of spaced skull pins operatively contacting an indicator, each of the indicators being movable in non-alignment with the axis and relative to the respective spaced skull pin along a direction parallel to the orientation of the respective spaced skull pin in response to the engagement force applied by the skull of the patient to the respective spaced skull pin, thereby to provide an indication of the load distribution of the engagement forces on said pair of spaced skull pins.

2. The skull clamp of claim 1 wherein each of said pair of skull pins resides within a bore located at an end of the rocker arm, and further comprising:

a pair of pin carrier assemblies, each pin carrier assembly held within the bore and holding the respective indicator in operative contact with the respective skull pin.

3. The skull clamp of claim 2 wherein each of the two pin carrier assemblies further comprises:

a spring biasing the respective indicator in a desired position relative to the frame, so that the indicator moves relative to the frame in response to force on the skull pin only after the force of the spring is overcome.

4. The skull clamp of claim 3 wherein each indicator includes markings to facilitate visual detection of the movement of the indicator relative to the frame, thereby to facilitate comparison of the load distribution between said pair of spaced skull pins.

5. A skull fixation device comprising:

a frame adapted to partially encircle the skull of a patient, the frame having at least one leg which is adapted to be located adjacent the skull when the fixation device is in use, the at least one leg being aligned substantially perpendicular to an axis which extends through the skull; and

a pair of spaced skull pins mounted in spaced relation on a swivel bracket located at said at least one leg of the frame, the pair of spaced skull pins being spaced from the axis and adapted to engage and hold the skull of the patient, each of the pair of spaced skull pins operatively contacting a respective indicator, the indicators being spaced from the axis and movable relative to the swivel bracket in response to the force applied by the skull to the respective skull pin, thereby to indicate the load distribution of the forces on the spaced skull pins,

wherein the swivel bracket is rotatable about the axis to facilitate placement of the pair of spaced skull pins in desired positions relative to the skull, and the swivel bracket remains a fixed distance, along the axis, from said at least one leg of the frame.

6. The skull fixation device of claim 5 and further comprising another leg forming part of the frame, and a third pin mounted to said another leg and oriented along the axis.