CEMENTED VS. CEMENTLESS FEMORAL FIXATION

This recommendation was upgraded from limited to moderate due to the risks of periprosthetic fracture, risks to acceptability as the vast majority of femoral stems implanted are cementless, as well as the importance of training surgeons on cement technique. Eleven low quality studies compared outcomes of cemented femoral stems versus cementless femoral stems in total hip arthroplasty for symptomatic osteoarthritis (Bloemheuvel 2022, Cnudde 2017, Dybvik 2020, Ekman 2019, Ennin 2021, Gandhi 2010, Havelin 1994, Jamsen 2014, Kelly 2022, Makela 2014, Pedersen 2021).

Bloemheuvel (2022), suggested that cemented femoral fixation had significantly positive effects on revision rates after 1, 3, and 5 years compared to cementless. Jamsen (2014) found that cementless femoral fixation had significantly positive effects on the risk of revision after 1 year compared to cemented. Makela (2014) indicated that cementless femoral fixation had significantly positive effects on revisions after 6 months and 15 years, deep infection at 6 months, and dislocation at 6 months for patients between the ages 65-74 compared to cemented. However, it also suggested that cemented femoral fixation had significantly positive effects on aseptic loosening and periprosthetic fracture at 6 months for patients between the ages of 65-74 compared to cementless. For patients over 75, this low-quality article indicated that cementless femoral fixation had significantly positive effects on revision after 15 years, deep infection at 6 months, and dislocation at 6 months compared to cemented. However, cemented femoral fixation had significantly positive effects on aseptic loosening at 6 months and periprosthetic fracture at 6 months for the same age group compared to cementless. Kelly (2022) found cementless femoral fixation had significantly positive effects on septic revision and loosening at 10 years compared to hybrid. However, it also suggested that cemented femoral fixation had significantly positive effects on periprosthetic fracture at 10 years compared to cementless.

Benefits/Harms of Implementation
Cemented femoral stems in total hip arthroplasty are associated with lower risk of periprosthetic fracture particularly in older patients. However, there is a risk of bone cement implantation syndrome with the use of cement during total hip arthroplasty particularly in patients with poor renal, cardiac, or pulmonary function (Rassir 2021). The decision to use cemented or cementless femoral fixation should be individualized to each patient as it may be influenced by individual patient circumstances.

Outcome Importance
As the number of older patients undergoing total hip arthroplasty increases annually, the risk of periprosthetic fractures has continued to rise. Mortality rates after periprosthetic fractures are as high as 18% so mitigating this risk is important (Shields 2014). This recommendation was upgraded from limited to moderate to emphasize the importance of mitigating the risk of periprosthetic fractures in total hip arthroplasty.

Cost Effectiveness/Resource Utilization
While cementless fixation is widely utilized in total hip arthroplasty, bone cement is widely available as it is the most common fixation method for total knee arthroplasty. The cost-effectiveness of cemented versus cementless femoral fixation is complex and must take into account multiple factors including direct costs, including the costs of the prostheses and cement, as well as indirect costs, operating room and anesthesia time, and the cost of adverse events associated with their use.

Acceptability
In the United States, 95.2% of femoral stems implanted are cementless (AJRR 2022 Annual Report). The high utilization rates of cementless femoral fixation are multifactorial including longevity due to biologic ingrowth fixation, reduced operative time, lower risk of embolic debris, as well as lack of training on cement technique. Given this, there is a risk that this recommendation is not widely accepted. As a result, this recommendation was upgraded to a moderate strength recommendation due to this risk.

Feasibility
While cemented femoral fixation is less utilized in the United States, it is widely utilized internationally with utilization of cemented stems reported up to 98% in some countries (Bunyoz 2020). Clinically, cemented fixation is sustainable and an effective method of femoral fixation. However, a major barrier to implementation of this recommendation is lack of surgical training on cement technique. As a result, this recommendation was upgraded to a moderate strength recommendation to emphasize the importance of surgical training incorporating cemented femoral fixation.

Future Research
The decision to utilize a cemented versus cementless femoral stem should be individualized to each patient and should take into account bone quality. There is not a widely available and adopted preoperative assessment for bone quality. Resultantly, age is often utilized as a surrogate. Future research is warranted to identify additional patient related factors beyond age that inform the decision to use cemented or cementless fixation and avoid complications, such as periprosthetic fractures. While cementless and cemented fixation are broad terms to describe fixations strategies in total hip arthroplasty, there are a variety of implant related differences (e.g., geometry, coatings) between implants in each group that should be considered. Future comparative research is warranted to investigate the unique differences in implants and technologies in each group. Long-term studies and registry data are important to assess the reliability and durability of current and future cemented and cementless femoral stems. Comparative cost-effectiveness data is also important and should be an area of future research.