What is a gender-specific implant?
A gender-specific total knee replacement implant is a prosthesis that is specifically designed either for a male or a female. The size of the implant is slightly different to accommodate for the slightly different size of the bones between genders.
Why develop a gender-specific implant?
Traditionally, implant designs have been made using "average" size data. This means that the designers of implants tried to find the "average" size at a joint, and then design implants that are both slightly larger and slightly smaller than the average.
Gender-specific implants are designed in a similar way, except that the "average" is different for a man's bone and a woman's bone. The idea behind doing this is that by better replicating the normal anatomy, the joint replacement implants may allow for better function, as well as improved durability.
Do the gender-specific implants help?
There is no data to suggest that creating a gender-specific implant design will help achieve the goals of better function or improved durability. Most orthopedic surgeons will tell you that implants already come in a variety of sizes that will accommodate almost any patient's anatomy.
Should I ask for a gender-specific implant?
It is clear that orthopedic implant companies are looking for ways to distinguish themselves. Sometimes solutions are created for problems that don't necessarily exist. Only time will tell if a gender-specific implant is actually a better, or worse, implant design. However, nothing suggests that it is an important determinant of a patient's satisfaction or outcome following joint replacement surgery.
Barrett, WP, "The need for gender-specific prostheses in TKA" Orthopedics. 2006 Sep;29(9 Suppl):S53-5.