Surgical factors associated with symptomatic implant removal after patella fracture.

Objectives: To determine whether certain types of fixation and other factors associated with the fixation could be identified that predict an increased risk of symptomatic implant removal.

Methods: We conducted a retrospective cohort study at our urban academic level 1 trauma center. Patients aged ≥18 years who underwent operative fixation for patella fracture were included. The primary outcome was symptomatic implant removal after operative fixation.

Results: Of the 186 study patients (mean age, 44 [SD 17] years, 65% male), 53 patients (28.5%) underwent symptomatic implant removal. Modifiable risk factors for symptomatic implant removal included the use of Kirschner (k)-wires (OR: 4.93; 95% CI, 1.89-14.10; p < 0.001), and a trend towards significance for implant prominence >5 mm (OR: 2.57; 95% CI, 0.93-7.93; p = 0.07). Symptomatic implant removal was also less likely in patients >45 years of age (OR: 0.14; 95% CI, 0.06-0.34; p < 0.01), of a racial minority (OR: 0.40; 95% CI, 0.17-0.88; p = 0.03), and a body mass index >25 kg/m (OR: 0.39; 95% CI, 0.18-0.84; p = 0.02). The final model demonstrated excellent prognostic performance, with an AUC of 0.83 (0.76-0.90).

Conclusion: We identified both modifiable and non-modifiable factors associated with symptomatic implant removal in patients with patella fractures. Surgeons should be aware that the use of k-wires and any implant prominence exceeding 5 mm might be associated with increased odds of symptomatic implant removal in patients with patella fractures.