As the demand for knee arthroplasty continues to grow year-on-year, purse holders are looking to perform the procedure more efficiently to deliver high quality care at lower costs. With implant costs accounting for ~25% of the total cost, the use of higher-cost implants – like cementless TKA – may be restricted to certain patients or prohibited altogether. However, recent evidence suggests that cost should not be a barrier to using cementless TKA.
This recent study shows that “although the general cost of cemented TKA implants is lower than their cementless counterparts, the actual cost of the procedure is less for cementless TKA when the cost of operating theatre time, cement, and cementing accessories is taken into account.”1
This was a single-centre randomised control trial of 147 knees (cemented n = 67 and cementless n = 80) of the same implant design. There were no revisions in either group at minimum 2-year follow-up, and clinical outcomes including pain and functional outcomes scores were similar at six weeks, and one and two years post-op.
Significant additional time costs (based on US data)
By contrast, the authors noted significant differences in procedural costs between the two modes of fixation. Operative time (incision to dressings applied) was 11.6 minutes longer in the cemented TKA group (93.7 mins) than the cementless TKA group (82.1 mins) (p = 0.001). From the literature, theatre time has been estimated to cost between $30 and $60 per minute. For this analysis, the authors used a cost of $36 per minute as reported in a recently published multi-centre study. Based on a cost of $36 per minute, the additional time cost for cemented TKA was $418.
Applying the lowest and highest cost estimates from the literature, the additional time costs could potentially range from $348 to $696 for cemented TKA.
Cement and accessory costs
When it came to cement and cement accessories, the least and most expensive options for both were analysed. The least costly option, which used two 40g units of plain cement and an open mixing bowl and spatula cost $170. Conversely, the costliest option, which used two 40g units of antibiotic cement and a cement gun-compatible vacuum mixing system, cost $625.
Additional procedural costs
This means that the additional procedural costs for cemented TKA (additional time costs + cementing costs) ranged from $588 to $1043/per surgery based on an estimated theatre cost of $36/minute. Applying the lowest and highest cost estimates for theatre time from the literature, the additional costs for cemented TKA could potentially range from $518 to $1,321. So while cementless TKA implants are typically more expensive, they may actually deliver similar outcomes at lower total cost. These findings do not consider the opportunity costs/greater efficiency of cementless TKA, allowing the possibility for more surgeries, nor the indirect savings from cementless TKA, which might include less staff overtime, improved staff satisfaction, and reduced blood loss due to shorter surgery times.
It was concluded that the overall procedural cost of implanting a cementless TKA is less than implanting a cemented TKA, and that therefore cost alone should not be a barrier to using cementless TKA.
