Periprosthetic knee fractures following robotic-assisted total knee arthroplasty: an observational incidence study

Periprosthetic knee fractures are rare but serious complications of total knee arthroplasty (TKA), the incidence of which is rising due to an aging population and rising TKA rates. They most commonly affect the distal femur, and these fractures are linked to factors such as osteoporosis and falls. Robotic-assisted TKA (RA-TKA) improves surgical precision but introduces risks, such as pin-site complications. This study aims to report the incidence rate of periprosthetic distal femur fractures after RA-TKA. This is a retrospective cohort study, which was conducted at single tertiary center. The study included 429 patients (503 knees) who underwent RA-TKA (2021-2025). Data were collected from electronic health records. Our study included 429 patients who underwent RA-TKA. The majority were aged 56-65 years (n = 216, 42.9%), and most were female (n = 396, 78.7%). The mean BMI of patients was 33.9 ± 5.2. Diabetes mellitus was the most prevalent comorbidity (n = 244, 48.5%) and renal disease was not significantly associated with periprosthetic knee fractures in exploratory analysis (p = 0.064). The incidence of periprosthetic fractures was 1.4% (n = 7), primarily due to mechanical falls (n = 5, 71.4%). This study showed that there is a low incidence of periprosthetic knee fractures following RA-TKA, and these fractures are primarily due to mechanical falls. While renal disease showed a borderline association, the study was underpowered to draw conclusions about risk factors, and negative findings should not be interpreted as evidence of no association. These findings primarily describe the incidence of periprosthetic fractures and support the need for continued postoperative vigilance following RA-TKA.