Ligament fixing and a method of attaching a ligament

Abstract

An artificial ligament is provided having an elongate body and two ends, with a loop being provided at least one of the ends and a loop liner being provided within the loop. A kit of artificial ligaments is also provided with each ligament in the kit having a different fixed length. Also provided are methods for determining a length of artificial ligament to be used within a prosthetic knee joint, selecting a ligament from a range or kit of ligaments, and implanting a prosthetic knee joint assembly comprising an artificial ligament.

What we claim is: 
     
         1 . An artificial knee ligament comprising an elongate body and two ends, wherein a loop is provided at at least one of the ends; and
 a loop liner provided within the loop.   
     
     
         2 . The artificial knee ligament of  claim 1 , wherein the loop liner is formed from a different material from the body of the ligament. 
     
     
         3 . The artificial knee ligament of  claim 1 , wherein the length of the ligament is fixed. 
     
     
         4 . The artificial knee ligament of  claim 1 , wherein the loop is configured to couple to a fixing provided on either a femoral or tibial component of a prosthetic knee joint. 
     
     
         5 . The artificial knee ligament of  claim 1 , wherein the loop liner covers an inside face of the loop. 
     
     
         6 . The artificial knee ligament of  claim 4 , wherein the loop liner is shaped to sit between the fixing of the prosthetic knee component, and the ligament loop. 
     
     
         7 . The artificial knee ligament of  claim 1 , wherein the loop liner is resilient and can be deformed elastically to allow the ligament loop to be pushed over an enlarged head of the fixing of the prosthetic component. 
     
     
         8 . The artificial knee ligament of  claim 1 , wherein the loop liner is moulded onto the loop of the ligament. 
     
     
         9 . The artificial knee ligament of  claim 1 , wherein the loop liner comprises a thimble. 
     
     
         10 . The artificial knee ligament of  claim 1 , wherein the loop liner is made from polyethylene. 
     
     
         11 . A method of implanting a prosthetic knee joint assembly, comprising a tibial component, a femoral component and an artificial knee ligament, comprising the steps of:
 implanting the tibial component or the femoral component into a patient;   coupling a preformed artificial ligament to the prosthetic components;   implanting the other component into the patient.   
     
     
         12 . The method of  claim 11 , wherein the first prosthetic component is implanted in a temporary manner. 
     
     
         13 . The method of  claim 11 , wherein the tibial component is implanted before the femoral component. 
     
     
         14 . The method of  claim 11 , further comprising the step of
 determining an appropriate length for a replacement knee ligament to link the tibial and femoral components of the prosthetic knee joint, this step being   completed prior to the step of coupling the preformed artificial ligament to the prosthetic components.   
     
     
         15 . The method of  claim 11 , further comprising the step of
 selecting a preformed artificial ligament of a suitable length from a set of artificial ligaments, this step being   completed prior to the step of coupling the preformed artificial ligament to the prosthetic components.   
     
     
         16 . The method of  claim 11 , further comprising the step of installing a final meniscal bearing, this step being performed prior to the step of implanting the second prosthetic component into the patient. 
     
     
         17 . The method of  claim 11 , further comprising the steps of
 installing a temporary meniscal spacer, this step being performed prior to the step of implanting the second prosthetic component into the patient; and   installing a final meniscal component between the tibial and femoral components of the prosthetic knee joint, this step being performed subsequently to the step of implanting the second prosthetic component into the patient.   
     
     
         18 . The method of  claim 11 , wherein the tibial prosthetic component comprises a fixed knee bearing. 
     
     
         19 . A method of determining a suitable length for an artificial knee ligament comprising the steps of:
 coupling first and second prosthetic components to a patient in a temporary manner;   creating a trial ligament using an elongate element extended around a first fixing on the first prosthetic component and a second fixing on the second component to form a continuous band;   cutting the band and removing the trial ligament from the surgical site; and   measuring the length of the reassembled band.   
     
     
         20 . The method of  claim 19 , wherein the first and/or second prosthetic component is a trial prosthetic component. 
     
     
         21 . The method of  claim 19 , wherein the first and/or second prosthetic component is a final prosthetic component 
     
     
         22 . The method of  claim 19 , wherein the fixings comprise bollards provided on the femoral and tibial prosthetic components. 
     
     
         23 . The method of  claim 19 , further comprising the step of
 installing a trial meniscal component between the tibial and femoral components of the prosthetic knee joint, this step being   performed prior to the step of creating a trial ligament.   
     
     
         24 . The method of  claim 23 , wherein the trial meniscal component is also the final meniscal component. 
     
     
         25 . The method of  claim 19 , wherein the elongate element comprises a trial ligament with one looped end and one open end which can be tied. 
     
     
         26 . The method of  claim 19 , wherein a pin is used to mark the required length of elongate element whilst fitted to the patient. 
     
     
         27 . The method of  claim 19 , wherein the elongate element comprises a zip tie. 
     
     
         28 . The method of  claim 19 , wherein the elongate element comprises markings allowing the length of the band to be determined from the markings on the elongate element. 
     
     
         29 . Instrumentation for measuring between first and second ligament fixings of prosthetic components comprising:
 an elongate body,   an arcuate portion provided at or towards one end of the elongate body and   a slideable jaw, configured to slide along the elongate body.   
     
     
         30 . The instrumentation of  claim 29 , wherein the elongate body further comprises a measurement scale. 
     
     
         31 . The instrumentation of  claim 29 , wherein the arcuate portion is configured to closely engage the first fixing. 
     
     
         32 . The instrumentation of  claim 29 , wherein the slideable jaw is configured to engage the second fixing. 
     
     
         33 . The instrumentation of  claim 29 , wherein the position of the slideable jaw can be selectively fixed relative to the elongate body. 
     
     
         34 . The instrumentation of  claim 33 , wherein the jaw and the elongate body are provided with cooperating formations and the jaw is fixed by rotating a portion of the jaw to engage the cooperating formations. 
     
     
         35 . The instrumentation of  claim 30 , wherein the measurement scale indicates the size of artificial ligament required to link the first and second fixings.