Summary

Press-fit TKA utilization has increased in recent years with press-fit TKA patients being younger, having fewer comorbidities, but also increased BMI compared with cemented TKA patients.

Abstract

Introduction

The utilization of cementless (press-fit) total knee arthroplasty (TKA) continues to increase. While early studies had more restrictive indications for press-fit TKA, the overall indications for its use have expanded. Controversy remains regarding patient populations that may benefit from press-fit TKA. The purpose of this study was to assess the utilization and risk factors for press-fit TKA failure in a large population of patients at a regional health system to assess whether current expanded indications are justified.i

Methods

All patients who underwent primary total knee arthroplasty (TKA) for degenerative joint disease at a large regional health system between 2015-2024 were retrospectively analyzed. Patients who underwent TKA for trauma/fracture, oncologic indications, or revisions were excluded. Patient demographics and complications were retrieved from the medical records. Differences between patients cemented and press-fit TKA in terms of post-operative measures of health and hospital utilization were assessed using multivariate regression and logistic regression models. Chi-square tests as well as t-tests were conducted to examine significance of relationship and differences in patient populations between independent categorical variables such as demographics, gender, and cement or press-fit TKA.

Results

A total of 26,257 patients underwent TKA for osteoarthritis indications by 132 surgeons operating at a total of 18 facilities within the authors’ health system; 25,154 (95.8%) were cemented and 1,103 (4.2%) patients had press-fit TKA.

Patients who received press-fit TKA were younger (mean 63.4 ± 8.4 years) compared to cemented TKA patients (mean 67.8 ± 8.9 years, p<0.01), but had a higher BMI (36.2 ± 7.1 mg/kg2) compared with cemented patients (35.7 ± 7.4 kg/m2, p<0.01). Elixhauser comorbidity index was higher in cemented TKA (2.2 ± 1.6) compared with press-fit TKA (1.9 ± 1.4). Press-fit TKA surgical time was significantly lower (80.0±21.0) compared with cemented TKA (85.8± 25.5).

Multivariate regression analysis controlling for BMI, age, race, and Elixhauser revealed that cemented TKA was associated with 0.31 more ED returns (p<0.01). Cemented TKA was also associated with an increase in surgery duration of 7.0 minutes of surgery, p<0.01. Logistic regressions analysis showed that the incidence of complications, or mortality within 30 days or within 1 year were not significantly associated with cemented TKA. Overall utilization rate of press-fit TKA significantly increased during the study period from 2016-2024 (p<0.01).

Additionally, cemented TKA was associated with a significant increase of 2.99, p<0.05, in the one-year score change of the patient-reported Knee injury and Osteoarthritis Outcome Score (KOOS).

Conclusion

This study reveals the significant increase in press-fit TKA utilization in recent years. Press-fit TKA patients are younger, have less comorbidities, but also increased BMI compared with cemented TKA patients. Press-fit TKA has shorter surgical time, but slightly higher ED returns with similar complications. Press-fit TKA appears to have similar performance compared with cemented TKA and is mostly utilized in younger patients.