CEMENTLESS FIXATION: CEMENTED FEMORAL & TIBIAL COMPONENTS VS. CEMENTLESS FEMORAL & TIBIAL COMPONENTS
Cemented femoral and tibial components or cementless femoral and tibial components in knee arthroplasty show similar rates of functional outcomes, complications, and reoperations, and conflicting evidence in comparative studies.

Rationale

In general, the body of evidence was notable for heterogeneity in study design, comparative study groups (including cementless, hybrid, and cemented fixation), and confounding results. As such, the recommendation has been downgraded.

There were twelve high quality studies (Demey 2011, Fernandez-Fairen 2013, Kim 2014, Lizaur-Utrilla 2014, Kendrick 2015, Pulido 2015, Van Hamersveld 2017, Nam 2019, Batailler 2020, Hampton 2020, Kim 2020, Murylev 2020) and seventeen low quality studies (Khaw 2002, Carlsson 2005, Baker 2007, Park 2011, Pandit 2013, Bagsby 2016, Kerens 2017, Boyle 2018, Nugent 2019, Manoli 2019, Deroche 2020, Irmola 2020, Lizaur-Utrilla 2020, Mohammad 2020, Gifstad 2021, Silverstein 2021, Quispel 2021) evaluating the use of various combinations of cemented versus cementless fixation of components (tibia, femur, patella) in total knee arthroplasty.

Registry data from the American Joint Replacement Registry (AJRR 2020) has shown that fully cementless fixation was found to have a significant decrease in cumulative percent revision compared to cemented fixation in males ≥65 years of age (HR=0.755, CI 0.631-0.905) and in patients <65 years of age reported to AJRR (HR=0.785, CI 0.664-0.927). Literature comparing complications and revision rates between fully cemented and uncemented fixation included one high quality study (Kim 2020) and nine low quality studies (Bagsby 2016, Kerens 2017, Boyle 2018, Manoli 2019, Nugent 2019, Irmola 2020, Deroche 2020, Mohammad 2020, Quispel 2020). Studies varied with respect to follow-up, ranging from 53 months to 25 years. Irmola (2020) showed a higher rate of all-cause revisions at 5 years in the cementless group, and Nugent (2019) showed higher rates of revision in the cementless group at 10 years. Two studies (Nugent 2019, Mohammad 2020) showed a significantly increased rate of fracture and revision in the cementless group at 5 and 10 years, respectively. Mohammad (2020) also showed higher rates of aseptic loosening in the cemented groups. However, Manoli (2019) and Bagsby (2016) showed higher revision rates with cemented fixation at 90 days and 6 years, respectively. Nevertheless, across comparative groups, no major differences existed between cemented and cementless fixation in any other studies with respect to rates of complications and re-operations, including studies with longer follow up.

Only small differences were seen with respect to outcome measures, depending on the particular comparative groups, length of follow up, and scoring instruments. Three high quality studies (Kim 2020, Hampton 2020, Murylev 2020) showed improved functional scores at 1 year and 25 years postoperatively in the uncemented group. Two low quality studies (Nugent 2019, Deroche 2020) showed better functional scores with cementless fixation at 6 months, 2 years, and 5 years. However, three high quality studies (Kendrick 2015, Van Hamersveld 2017, Nam 2019) and five low quality studies (Kerens 2017, Stempin 2017, Karachalios 2018, Mohammad 2020, Pacoret 2020) showed no significant difference in functional scores between groups at short-, mid-, and long-term follow-up, respectively.

Benefits/ Harms of Implementation

There are no known harms associated with implementing this recommendation. The decision to use cementless versus cementless fixation may be influenced by individual patient situations. The practitioner should be aware of the advantages and disadvantages of a variety of treatment methods. For example, intra-operative fracture during component insertion or failure of ingrowth may be of concern with certain cementless designs in patients with poor bone quality.

Future Research

Continued long term comparative studies between modern cemented and cementless component fixation options in knee arthroplasty will help to further define the utility of these component types, durability of fixation, and effect of evolving component designs (e.g., modular and monolithic) on patient-reported outcomes. Certainly, newer fixation materials (e.g., porous metals) should be evaluated in long term follow up. Identifying patient-specific factors that may inform the decision to utilize a particular fixation technique, or to avoid complications associated with particular fixation strategies, is important. Registry data. Long term studies (greater than ten years clinical follow up) should inform durability of specific components and may serve to analyze implant-specific complications and revision risk. Given some variability in the patient-reported outcome measures between treatment groups, particularly in high quality studies, more clinical data may discern subtle differences in clinical outcomes based on the use of cemented or cementless component fixation. Issues of cost and cost-effectiveness should also be incorporated into future clinical studies.