Instruments and methods for flexion gap adjustment

摘要

A flexion gap instrument (30) is configured to mate with a ligament tensioning tool (20), such as known distraction devices and pivoting knee balancers. The instrument facilitates making A/P resections in the femur for placement of a femoral prosthesis component to maintain an optimum symmetric flexion gap, which will avoid the risk of medial or lateral laxity in flexion, instability of articulating component dislocation. The instrument (30) includes a base (32) that is configured to sit within the ligament tensioning device (20), and a vertically extending upstanding portion (33) that is configured to mate with a cutting block (45) or other knee arthroplasty instrument that must be positioned relative to the distal end of the femur. The upstanding portion (33) includes a measurement plate that bears a scale (37) indicating a flexion gap distance. The scale (37) can be used to orient and align the cutting block (45) in its proper position relative to the distal end of the femur, and to orient the cutting block (45) parallel with the tibial plateau with the ligaments properly and equally tensed. In certain embodiments, a leaf spring (40) can be incorporated into the upstanding portion (33) to help support the cutting block (45) and provide means for temporarily positioning the cutting block (45) on the flexion gap instrument (20) without the need for additional or supplemental locks.A flexion gap instrument (30) is configured to mate with a ligament tensioning tool (20), such as known distraction devices and pivoting knee balancers. The instrument facilitates making A/P resections in the femur for placement of a femoral prosthesis component to maintain an optimum symmetric flexion gap, which will avoid the risk of medial or lateral laxity in flexion, instability of articulating component dislocation. The instrument (30) includes a base (32) that is configured to sit within the ligament tensioning device (20), and a vertically extending upstanding portion (33) that is configured to mate with a cutting block (45) or other knee arthroplasty instrument that must be positioned relative to the distal end of the femur. The upstanding portion (33) includes a measurement plate that bears a scale (37) indicating a flexion gap distance. The scale (37) can be used to orient and align the cutting block (45) in its proper position relative to the distal end of the femur, and to orient the cutting block (45) parallel with the tibial plateau with the ligaments properly and equally tensed. In certain embodiments, a leaf spring (40) can be incorporated into the upstanding portion (33) to help support the cutting block (45) and provide means for temporarily positioning the cutting block (45) on the flexion gap instrument (20) without the need for additional or supplemental locks.