External fixation apparatus and method

Abstract

A bone fixation apparatus and method are provided that allow a user to push bone pins into engagement with bones with more precision and accurate feel as to proper engagement and the clamping forces between the pins and bone over prior devices utilizing applicator guns and the like. Fine tuning of the clamping forces is also contemplated. Compact and highly ergonomic bone fixators are provided which allow the user to remain close to the pin application site during clamping of the pins onto the bone. Significant flexiblity is preferably incorporated by having two adjustably connected positioner bodies which can each mount a pin holder module releasably attached thereto. A fixation system with improved rigidity is also provided by way of independent clamping members for each of a pair of rod mounts on each pin positioner. The independent clamp members keeps their size to a minimum while allowing the angular separation of connecting rods secured in the rod mounts and spanning and interconnecting two fixators to be optimized, e.g. approximately eighty degree angular spacing, from a system stability standpoint.

1 . A bone fixation system for being rigidly attached to a bone, the bone fixation system comprising: 
 a plurality of bone fixators each including at least one pin positioner member and at least one pin supported by the positioner for being advanced into gripping engagement with the bone;    rod mounts at predetermined positions along each of the positioner members so that there is a predetermined angular spacing therebetween; and    a pair of rods for interconnecting the bone fixators received by the rod mounts at the predetermined positions of the fixator positioner member with separation of the rods from a generally coplanar relation with the bone having the pins of the fixators in gripping engagement therewith being substantially optimized by the predetermined angular spacing of the rod mounts of the positioner members to provide stability of the interconnected fixators attached to the bone.    
   
   
       2 . The bone fixation system of  claim 1  wherein the positioner members have an arcuate configuration to keep spacing of the positioner members from the bone to a minimum.  
   
   
       3 . The bone fixation system of  claim 1  wherein the predetermined angular spacing between the rod mounts is approximately 80 degrees.  
   
   
       4 . The bone fixation system of  claim 1  wherein the positioner members each include a rigid body having end portions thereof, the rod mounts include flexible receptacles at the end portions of each of the bodies, and an independent clamping member for each of the receptacles that clamps on the flexible receptacles for fixing the rods therein.  
   
   
       5 . The bone fixation system of  claim 1  wherein the rod mounts each comprise a resilient ball having an opening in which one of the rods is received and a locating portion of the ball which keeps the opening thereof accessible for receiving the rod therein.  
   
   
       6 . The bone fixation system of  claim 1  wherein the bone fixators each include a pair of pin positioner members that each support at least one bone pin and that are adjustably connected to each other with the rod mounts being on one of the positioner bodies.  
   
   
       7 . A method of fixing bones with bone fixators having bone pins for engaging the bones, the method comprising: 
 manipulating a pin positioner supporting the bone pins to position the pins for being engaged onto a bone;    manually pushing at least one displaceable pin through a pin holder at one end of the positioner to cause the pin to shift in an advancing direction into engagement with the bone at an advanced position thereof; and    automatically locking the pin in the advanced position thereof in the pin holder upon release of the manual pushing force applied thereto.    
   
   
       8 . The method of  claim 7  including displaceably supporting another pin with the positioner, and 
 repeating the manual pushing and automatic locking steps with the other displaceable pin through another pin holder at the other end of the positioner.    
   
   
       9 . The method of  claim 7  wherein the one pin is manually pushed via incremental ratcheting of the pin to the advanced position thereof.  
   
   
       10 . The method of  claim 7  including making fine adjustments to the advanced position of the pin and providing high resolution of pin-to-bone engagement forces to a user.  
   
   
       11 . The method of  claim 10  wherein the fine adjustments are made by turning a screw device, and 
 locking the screw device against turning after the fine adjustments are made.    
   
   
       12 . The method of  claim 7  wherein the pin positioner is manipulated by one hand of a user with fingers of the one hand used to manually push the pin in the advancing direction to provide for one-handed operation of the bone fixator.  
   
   
       13 . The method of  claim 7  wherein the pin positioner comprises a pair of adjustably connected members each having a pin holder at an end thereof, and 
 adjusting the members to each other to change relative positioning of the pin holders and the pins carried thereby.    
   
   
       14 . The method of  claim 7  including rigidly connecting the pin positioner to another pin positioner having bone pins advanced into engagement with the bone or another bone.