Artificial knee joint replacement operation instrument

Abstract

When using an artificial knee joint replacement operation instrument, the amount of labor required to attach a tibial insert trial to a patient is further reduced. An artificial knee joint replacement operation instrument has a template to be attached to a proximal portion of a tibia, a tibial insert trial for placement on the template, and a spacer configured to be arranged in a partial area of the template in an inward-outward direction of the patient and in a central portion of the template, and inserted between the template and the tibial insert trial. When the tibial insert trial has been placed on the template, a predetermined insertion space, into which the spacer is to be inserted, is formed between the template and the tibial insert trial. In the inward-outward direction, a length of the insertion space is set larger than a length of the spacer.

1 . An artificial knee joint replacement operation instrument comprising:
 a template to be attached to a proximal portion of a tibia of a patient;   a tibial insert trial to be placed on the template; and   a spacer configured to be arranged in a partial area of the template in an inward-outward direction of the patient and in a central portion of the template, and inserted between the template and the tibial insert trial,   wherein, when the tibial insert trial has been placed on the template, a predetermined insertion space, into which the spacer is to be inserted, is formed between the template and the tibial insert trial, and   in the inward-outward direction, a length of the insertion space is set larger than a length of the spacer.   
     
     
         2 . The artificial knee joint replacement operation instrument according to  claim 1 ,
 wherein leading end portions of the spacer in an inserting direction in which the spacer is inserted into between the template and the tibial insert trial include tapered portions which are formed into shapes that are tapered.   
     
     
         3 . The artificial knee joint replacement operation instrument according to  claim 1 ,
 wherein rails are formed in portions in which the template and the tibial insert trial face each other, and   the spacer is configured to slidably mate with the rails.   
     
     
         4 . The artificial knee joint replacement operation instrument according to  claim 1 , further comprising:
 a tilt restriction mechanism for restricting tilting of the tibial insert trial relative to the template around an axis of the tibia that extends in a front-rear direction,   wherein the tilt restriction mechanism includes: first tilt restriction portions which are formed on an upper face side of the template; second tilt restriction portions which are formed on a lower face side of the spacer and can mate with the first tilt restriction portions respectively; third tilt restriction portions which are formed on an upper face side of the spacer; and fourth tilt restriction portions which are formed in the tibial insert trial and can mate with the third tilt restriction portions, respectively.   
     
     
         5 . The artificial knee joint replacement operation instrument according to  claim 4 ,
 wherein the third tilt restriction portions are formed in a stopper which is provided on a front end upper face of the spacer, and   the fourth tilt restriction portions are formed in a cutout portion which is formed at a front end of the tibial insert trial and receives the stopper.   
     
     
         6 . The artificial knee joint replacement operation instrument according to  claim 1 , further comprising:
 a position shift restriction mechanism for restricting a position shift of the tibial insert trial in the inward-outward direction of the patient relative to the template,   wherein the position shift restriction mechanism includes: a first shift restriction portion which is formed in the template; and a second shift restriction portion which is formed in the tibial insert trial and faces the first shift restriction portion in the inward-outward direction.   
     
     
         7 . The artificial knee joint replacement operation instrument according to  claim 1 ,
 wherein the template includes penetrating portions through which a fixing member for fixing the template to the tibia passes, and   the template is configured such that positions of the penetrating portions differ from a position of the spacer in the inward-outward direction of the patient.