Researchers at Hospital for Special Surgery (HSS) have used a novel, advanced imaging technique known as multi-acquisition variable-resonance image combination selective magnetic resonance imaging (MRI) to quantify and compare fixation in cemented versus cementless total knee arthroplasty (TKA).
Although this was a small study – only 40 total patients were evaluated – the researchers found that cementless fixation provided excellent biologic fixation of knee implants, similar to fixation with cement, and even improved fixation of implant components in some areas in the joint.
The study has been published online by Arthroplasty Today.
“Overall, traditional knee replacement offers excellent outcomes and longevity,” said lead investigator Geoffrey H. Westrich, MD, a hip and knee surgeon from HSS. “However, younger patients generally put more demands on their joint, causing more wear and tear and potential loosening. The cemented knee implant used in a traditional joint replacement usually lasts 15 to 20 years.
“Early-generation cementless implants had numerous design ﬂaws resulting in loosening and poor survivorship compared [with] cemented knee replacements. More contemporary cementless knee components, such as those used in our study, utilize highly porous surfaces to promote biologic ﬁxation of the prosthesis. This should improve outcomes.”
For this study, the MRIs of 20 patients who had a cementless TKA were compared with the MRIs of a matched control group of 20 patients with a cemented TKA. The images were reviewed by a fellowship-trained musculoskeletal radiologist, who was looking for evidence of fluid, fibrous tissue, and osteolysis in the patellar, femoral, and tibia components. This radiologist specializes in the interpretation of joint replacement MRI and has more than 20 years of experience in assessing bony ﬁxation of knee replacement components.
The data showed “robust ﬁxation of the cementless knee replacement components, with results comparable to the cemented total knee replacements,” Dr. Westrich said. “And while there was no clinically significant difference regarding overall fixation in the knee, there were some component areas in which cementless fixation appeared to be superior.”
In general, candidates for cementless procedures are under age 70 and have good bone quality to promote biologic fixation.
“While our study found that early ﬁxation of cementless total knee components are comparable, if not superior, to cemented total knee replacement, further study with a larger number of patients over a lengthier time period is needed to assess long-term durability and fixation,” Dr. Westrich said.
The full text of the study is available here.
Mosich GM, Potter HG, Koff MF, Sacher SE, Mishu M, Westrich GH. Multiacquisition variable-resonance image combination magnetic resonance imaging to study detailed bone apposition and fixation of cementless knee system compared to cemented total knee replacements. Arthroplast Today. 2022 Aug 30;17:126-131. doi: 10.1016/j.artd.2022.06.013. eCollection 2022 Oct.