Determining the Joint Line Position Using the Adductor Ratio in Severe Varus Knee Osteoarthritis A Comparison With Other Measurement Techniques in Total Knee Replacement Patients Over 65

What this Trial Is About

Researchers are evaluating methods to accurately restore the joint line position during Total Knee Arthroplasty TKA in patients with severe varus deformity due to Type M gonarthrosis, a form of advanced knee osteoarthritis. This is important because proper joint line restoration affects knee function, pain, implant wear, and overall patient satisfaction. The study compares patients with two types of gonarthrosis deformities to find the best technique for determining the joint line using preoperative and intraoperative measurements, focusing particularly on the adductor ratio method. The study involves patients undergoing cemented bicondylar posterior cruciate ligament PCL substituting total knee replacement. Two patient groups include those with intraarticular varus deformity and those with metaphyseal varus deformity, both having severe osteoarthritis. Researchers will observe and measure anatomical landmarks during surgery and on radiographs before and after the procedure. This includes measuring the distance between specific bone landmarks and the joint line to assess which method most reliably determines the joint line position. Participants will undergo preoperative radiological assessments and intraoperative caliper measurements followed by postoperative X-rays over two years. Functional outcomes will be evaluated using the Hospital for Special Surgery HSS knee score before surgery and at one year after. The primary measurement is the accuracy of joint line determination by the adductor ratio compared to other techniques. This observational study aims to improve surgical planning and outcomes in complex knee replacement cases with severe deformity.

Adductor Ratio in Severe Varus Gonarthrosis