Head fixation device

Abstract

Head fixation devices and methods of fixating heads of patients for surgical procedures. The head fixation devices generally respectively comprise a skull clamp, a skull clamp arc assembly movable relative to the skull clamp, and a plurality of skull pins operable to engage and fixate heads of patients during neurosurgical and cervical spine procedures. The skull clamp can comprise a single skull pin on each end of the clamp. The two skull pins apply substantially equal compressive forces to the head of a patient. The skull clamp arc assembly, and an arc skull pin thereof, is pivotable to engage and disengage the patient's head for additional fixation support of the head.

What is claimed is: 
     
         1 . A head fixation device comprising:
 a skull clamp positionable about a head of a patient, wherein the skull clamp comprises a first end and a second end opposing the first end;   a first skull pin provided to the first end of the skull clamp and a second skull pin provided to the second end of the skull clamp, wherein the first and second skull pins are aligned in opposition along an axis, and wherein at least one of the first and second skull pins is movable relative to the first and second ends such that the first and second skull pins engage and disengage the head of the patient when the skull clamp is positioned thereabout; and   a skull clamp arc assembly comprising an arc skull pin, wherein the skull clamp arc assembly extends from one of the first and second ends of the skull clamp such that the arc skull pin is offset from the axis, and wherein the skull clamp arc assembly is movable relative to the first and second ends of the skull clamp such that the arc skull pin is operable to engage and disengage the head of the patient with movement of the skull clamp arc assembly.   
     
     
         2 . The head fixation device of  claim 1 , wherein:
 the one of the first and second ends of the skull clamp from which the skull clamp arc assembly extends comprises a locking assembly operable to secure the skull clamp arc assembly to the one of the first and second ends, and   the locking assembly comprises a locking plate, an o-ring, and a snap ring.   
     
     
         3 . The head fixation device of  claim 2 , wherein:
 the locking plate is operable to secure to the one of the first and second ends of the skull clamp from which the skull clamp arc assembly extends and to support the skull clamp arc assembly and comprises a post and a depression provided proximally to an end of the post,   the o-ring is positionable about the post of the locking plate and is operable to facilitate movement of the skull clamp arc assembly relative to the locking plate, and   the snap ring is operable to secure to the depression of the locking plate and secure the skull clamp arc assembly to the post of the locking plate.   
     
     
         4 . The head fixation device of  claim 1 , wherein the skull clamp arc assembly is rotatable relative to the first and second ends such that the skull clamp arc assembly rotates about the axis. 
     
     
         5 . The head fixation device of  claim 1 , wherein the skull clamp arc assembly is pivotable relative to the first and second ends such that the arc skull pin pivots toward and away from the axis so as to engage and disengage the head of the patient when the skull clamp is positioned thereabout. 
     
     
         6 . The head fixation device of  claim 5 , wherein the skull clamp arc assembly includes a plurality of pivot points such that the arc skull pin is pivotable relative to the axis. 
     
     
         7 . The head fixation device of  claim 6 , wherein the skull clamp arc assembly is rotatable relative to the first and second ends such that the skull clamp arc assembly rotates about the axis with pivoting of the arc skull pin about at least one of the plurality of pivot points to a maximum pivot away from the axis. 
     
     
         8 . The head fixation device of  claim 5 , wherein the skull clamp arc assembly comprises:
 a rocker guide assembly securable to the one of the first and second ends from which the skull clamp arc assembly extends;   a lower rocker assembly securable to the rocker guide assembly at a first pivot point and pivotable about the first pivot point toward and away from the axis; and   an upper rocker assembly securable to the lower rocker assembly at a second pivot point and pivotable about the second pivot point toward and away from the axis.   
     
     
         9 . The head fixation device of  claim 8 , wherein the rocker guide assembly is rotatable relative to the first and second ends such that the skull clamp arc assembly rotates about the axis with pivoting of at least one of the lower rocker assembly and the upper rocker assembly about the first pivot point and the second pivot point, respectively, to a respective maximum pivot away from the axis. 
     
     
         10 . The head fixation device of  claim 8 , wherein the rocker guide assembly comprises a body, a locking pin, a recess in the body at least partially housing the locking pin, a locking lever engaged with the locking pin, a cam movable to engage and disengage the locking lever, and a channel through the body through which the rocker guide assembly is securable to the one of the first and second ends of the skull clamp. 
     
     
         11 . The head fixation device of  claim 10 , wherein:
 the rocker guide assembly is operable such that pivoting of the lower rocker assembly about the first pivot point to the maximum pivot away from the axis moves the locking pin to an unlocked state so that the skull clamp arc assembly is rotatable relative to the first and second ends such that the skull clamp arc assembly rotates about the axis, and   the rocker guide assembly is operable such that pivoting of the lower rocker assembly about the first pivot point other than to the maximum pivot maintains the locking pin in a locked state so that the skull clamp arc assembly is not rotatable relative to the first and second ends.   
     
     
         12 . The head fixation device of  claim 8 , wherein the lower rocker assembly comprises a lower rocker arc and pawl lever. 
     
     
         13 . The head fixation device of  claim 12 , wherein:
 the lower rocker arc is pivotable about the first pivot point, and   the pawl lever is movable between an unlocked state in which the upper rocker assembly is pivotable about the second pivot point and a locked state in which the upper rocker assembly is not pivotable about the second pivot point.   
     
     
         14 . The head fixation device of  claim 13 , wherein the upper rocker assembly comprises an upper rocker arc operable to receive and support the arc skull pin. 
     
     
         15 . The head fixation device of  claim 14 , wherein the arc skull pin is operable to engage and disengage the head of the patient with pivoting of the upper rocker arc about the second pivot point toward and away from, respectively, the axis. 
     
     
         16 . The head fixation device of  claim 15 , wherein the arc skull pin is movable independently of and relative to the upper rocker arc in which the arc skull pin is supported. 
     
     
         17 . The head fixation device of  claim 1 , wherein the first skull pin and the second skull pin respectively comprise a tip operable to engage and disengage the head of the patient when the skull clamp is positioned thereabout, a plunger operable to support the tip, a plunger guide operable to control movement of the plunger and the tip, a compression spring operable to translate movement of the plunger guide to the plunger and the tip, and an indicator operable to indicate a compressive force provided by the tip against the head of the patient when the skull clamp is positioned thereabout. 
     
     
         18 . The head fixation device of  claim 1 , wherein the head fixation device comprises multiple skull clamp arc assemblies that extend from the first and second ends of the skull clamp. 
     
     
         19 . A head fixation device comprising:
 a skull clamp positionable about a head of a patient, wherein the skull clamp comprises a first end and a second end opposing the first end;   a first skull pin provided to the first end of the skull clamp and a second skull pin provided to the second end of the skull clamp, wherein the first and second skull pins are aligned in opposition along an axis, and wherein at least one of the first and second skull pins is movable relative to the first and second ends such that the first and second skull pins engage and disengage the head of the patient when the skull clamp is positioned thereabout; and   a skull clamp arc assembly comprising an arc skull pin, wherein the skull clamp arc assembly extends from one of the first and second ends of the skull clamp such that the arc skull pin is offset from the axis, wherein the skull clamp arc assembly is rotatable relative to the first and second ends such that the skull clamp arc assembly rotates about the axis, and wherein the skull clamp arc assembly is pivotable relative to the first and second ends such that the arc skull pin pivots toward and away from the axis.   
     
     
         20 . A method of fixating a head of a patient, wherein the method comprises:
 providing a head fixation device operable to fixate the head of the patient, wherein the head fixation device comprises:
 a skull clamp comprising a first end and a second end opposing the first end, a first skull pin provided to the first end of the skull clamp and a second skull pin provided to the second end of the skull clamp, wherein the first and second skull pins are aligned in opposition along an axis, and 
 a skull clamp arc assembly comprising an arc skull pin, wherein the skull clamp arc assembly extends from one of the first and second ends of the skull clamp such that the arc skull pin is offset from the axis, 
   positioning the head fixation device about the head of the patient such that the first and second ends of the skull clamp are positioned about the head of the patient;   moving at least one of the first and second skull pins relative to the first and second ends of the skull clamp such that the first and second skull pins engage the first and second sides of the head of the patient;   rotating the skull clamp arc assembly relative to the first and second ends such that the skull clamp arc assembly rotates about the axis to selectively position the arc skull pin over a third side of the head of the patient; and   pivoting the skull clamp arc assembly relative to the first and second ends such that the arc skull pin pivots to engage the third side of the head of the patient,   wherein engagements of the first, second, and third sides of the head of the patient by the first skull pin, the second skull pin, and the arc skull pin, respectively, sufficiently fixate the head of the patient.