The mechanical axis of the knee is the line extending from the center of the hip joint to the middle of the ankle joint.
A deviation from straight alignment is sometimes described as bow-legs or knock-knees. When a knee is not aligned properly in the leg axis, it may cause overstraining and can lead to increased wear of the cartilage layer on the inside and/or outside of the knee joint, causing arthritis.
One of the main goals of partial or total knee replacement is to restore natural joint alignment so that the weight of the body runs through the center of the knee, evenly distributing stress and preventing wear. Brainlab develops medical technology to help guide surgeons to achieve mechanical joint alignment during partial or total knee replacement surgery. Studies have demonstrated that computer assisted surgery leads to better functional outcome and patient quality-of-life outcome.1
1 ‘Does Accurate Anatomical Alignment Result in Better Function and Quality of Life? Comparing Conventional and Computer-Assisted TKA’; J Arthroplasty. 2009 Jun; 24(4):560-9. Epub 2008; Choong P.F., Dowsey M.M., Stoney J.D.