Alignment guide with spirit level

Abstract

An alignment guide is described that includes a shaft having a longitudinal axis and a housing attachable to the shaft and rotatable about a first axis that is substantially perpendicular to the longitudinal axis. A guide arm the extends from the housing at a predetermined angle along a second axis. A spirit level is connected to the housing on a plane aligned with the predetermined angle.

1 . An alignment guide, comprising:
 a shaft having a longitudinal axis;   a housing attached to the shaft and rotatable about a first axis that is substantially perpendicular to the longitudinal axis;   a guide arm that extends from the housing at a predetermined angle along a second axis; and   a spirit level connected to the housing on a plane aligned with the predetermined angle.   
     
     
         2 . The alignment guide of  claim 1 , wherein the spirit level comprises a first elongated tube, and a second elongated tube arranged to be perpendicular to the first elongated tube, the first tube being aligned with the longitudinal axis. 
     
     
         3 . The alignment guide of  claim 2 , wherein the first and second tubes each contain a liquid having a bubble disposed therein, and have respective first and second indicator lines that indicate a center position for a bubble that moves within each tube. 
     
     
         4 . The alignment guide of  claim 3 , wherein the first tube is adapted such that, when a bubble is in the center position of first tube, the shaft is at a pre-planned inclination angle. 
     
     
         5 . The alignment guide of  claim 3 , wherein the second tube is adapted such that, when a bubble is in the center position of second tube, the shaft is at a pre-planned version angle. 
     
     
         6 . The alignment guide of  claim 1 , wherein the predetermined angle ranges from 30 to 50 degrees. 
     
     
         7 . The alignment guide of  claim 1 , wherein the spirit level is a substantially ovate container partially filled with a liquid, and wherein the container has a bubble disposed therein, a center, and has at least one indicator marking oriented substantially at the center. 
     
     
         8 . The alignment guide of  claim 7 , wherein the spirit level is adapted such that, when a bubble is positioned beneath the at least one indicator marking, the shaft is at a pre-planned inclination and anteversion angle. 
     
     
         9 . The alignment guide of  claim 1 , wherein the housing comprises a base attached to the shaft, and a plate rotatable about the first axis relative to the base, the first portion being attached to the plate. 
     
     
         10 . A method of aligning an alignment guide relative to a reamed acetabulum of a patient, the patient being positioned on an operating table and having a long axis, comprising the steps of:
 manipulating an alignment guide comprising a shaft having a distal end and a longitudinal axis, a guide arm rotatably attached to the shaft about a first axis substantially perpendicular to the longitudinal axis, and a spirit level attached to the guide arm, the spirit level including a container having a liquid, a bubble disposed within the container, and at least one indicator marking on the container;   rotating the guide arm about the first axis relative to the shaft;   contacting the distal end of the shaft with the reamed acetabulum; and   while maintaining contact between the distal end of the shaft and the reamed acetabulum, adjusting the position of the alignment guide until the bubble is positioned beneath the at least one indicator marking.   
     
     
         11 . The method of  claim 10 , wherein a cup or trial is attached to the distal end of the shaft and the contacting step comprises the step of locating the cup or trial within the reamed acetabulum. 
     
     
         12 . The method of  claim 10 , wherein the spirit level comprises a first elongated tube and a second elongated tube arranged to be perpendicular to the first elongated tube, the first tube being aligned with the longitudinal axis, and wherein the first and second tubes each contain a liquid having a bubble disposed therein, and have respective first and second indicator lines that indicate a center position for a bubble that moves within each tube, and further comprising the step of while maintaining contact between the distal end of the shaft and the reamed acetabulum, adjusting the position of the alignment guide until the bubble disposed in the first tube is positioned beneath the indicator lines of the first tube. 
     
     
         13 . The method of  claim 12 , further comprising the step of adjusting the position of the alignment guide until the bubble disposed in the second tube is positioned beneath the indicator lines of the second tube.