What are the actual costs of cemented versus cementless total knee arthroplasty (TKA)?
A group of researchers pooled data on the cost of operative time, implants, cement, and cementing accessories and arrived at an answer. Their work, “The cost of implanting a cemented versus cementless total knee arthroplasty,” was published in the June 30, 2019 edition of The Bone and Joint Journal.
Co-author Robert Barrack, M.D., with the Department of Orthopedic Surgery at Washington University School of Medicine in St. Louis, Missouri, explained the rationale behind this study to OTW, “With advances in technology, specifically porous coated, uncemented, ingrowth surfaces (3-D printing and additive manufacturing) there is a substantial move towards uncemented TKA.”
“Currently almost all total hips in the U.S. are implanted without cement whereas over 85% or so of total knee replacements are still implanted with cement. This is changing fairly rapidly with more surgeons implanting these newer components without cement.”
“This switch occurred on the hip side about 30 years ago when the market switched dramatically from cemented to cementless. The multiple steps involved in high quality cement technique added a lot of variability to the procedure as well as additional time and cost for the cement and accessories.”
To calculate actual costs, the study authors measured operative time and found that the average operative time for cemented TKA was 11.6 minutes longer than cementless TKA (93.7 minutes vs 82.1 minutes). Assuming that the cost per minute of operating theater time is $36, the authors concluded that total time cost was $418 higher for cement TKA versus cementless.
The authors also checked the costs of cost of cement and accessories and found that they ranged from $170 to $625.
So, overall, the authors calculated that the cost of cemented TKA was typically $588 and $1,043, depending on technique, and, therefore, $366 more expensive than going cementless.
Dr. Barrack wrapped up the takeaway from this study for OTW, “One of the barriers to adoption of cementless implants is that they are somewhat more expensive. When I made the switch from cemented hip stems (at MGH [Massachusetts General Hospital] during my fellowship 100% of stems were cemented), we did a study at Tulane that looked at the total cost per case when all of the cement, accessories, and time were factored in, not just the cost of the metal parts.”
“The cementless stems were actually less costly to implant and thus cost should not be a barrier to switching from cemented to cementless.”
“We basically repeated this study published over 20 years ago and found the same results on the knee side as we did on the hip long ago. Most total knees at our institution are implanted without cement because of the clinical results which is at least as good both immediately and at two years with the increased efficiency and elimination of all of the variables introduced when cementing components.”
“The conclusion is the same as the hip study: cases are faster and more efficient without cement and when the total cost is considered there is little or no difference in cost. In fact, if a surgeon uses pre-mixed antibiotic cement, which many do, cementing a total knee can be more costly than cementless.”
