Single-Radius vs. Multi-Radius Femoral Design in Total Knee Arthroplasty

Total Knee replacement or knee arthroplasty, is a surgical technique to resurface a knee impaired
by arthritis. Plastic and metal parts are used to cover the bony ends of the knee joint, along with
the kneecap. This surgery is indicated for patients with severe arthritis or a severe knee injury.
Numerous types of arthritis may affect the knee joint. Osteoarthritis, which is considered most
common degenerative joint disease that affects mostly middle-aged and older adults, may cause
the collapse of joint cartilage and adjacent bone in the knees. Rheumatoid arthritis, is considered
an autoimmune disases results in inflammation of the synovial membrane which lead to pain
and stiffness. Traumatic arthritis, arthritis due to injury, may cause damage to the cartilage of the
The objective of knee replacement surgery is to resurface the parts of the knee joint that have
been damaged and to relieve knee pain that cannot be handled by other treatments.
Although the single-radius (SR) femoral design is known to have theoretical advantages in many
aspects, studies of clinical outcomes that compare the SR with the multiple-radius (MR) femoral
design are controversial.
A Meta-analysis study reporting the clinical outcomes of 2212 knee replacements using the SR
(n = 948) compared with the multiradius (MR; n = 1361) femoral design. Comparing SR with
MR, we observed the Knee Society Score for the knee (KSS-knee), KSS-function, knee flexion,
range of motion, complications, isometric peak torque of knee, and survival rate.
The range of motion of SR knees was lower than that of MR knees. No variances were stated in
the analyses of KSS-knee, KSS-function, knee flexion, complications, isometric peak torque of
the knee, and survival rate.
This meta-analysis does not provide clinical support for the earlier stated theoretical advantages
of the SR implant design.
1. Knee Replacement Surgery Procedure. (2021). Retrieved 16 October 2021, from
2. Liu, S., Long, H., Zhang, Y., Ma, B., & Li, Z. (2016). Meta-Analysis of Outcomes of a
Single-Radius Versus Multi-Radius Femoral Design in Total Knee Arthroplasty. The
Journal Of Arthroplasty, 31(3), 646-654. doi: 10.1016/j.arth.2015.10.017