High risk of complications following surgical treatment of patella fractures - a cross-sectional study of 798 patients with mean 6.4 years follow-up.

PURPOSE: This study aimed to investigate the incidence of early and late complications following treatment of patella fractures. Secondary aims were to investigate the association between early and late complications and the patient-reported outcome measurement, the Knee Injury and Osteoarthritis outcome score (KOOS).

METHODS: Cross-sectional study including all patients recorded with a patella fracture residing in the Northern Region of Denmark between 2010 and 2020. Early (before 3 months) and late complications were investigated by retrospective review of charts and x-rays. All patients were invited to participate in the study by reporting current knee-specific symptoms. The KOOS was used to investigate patient-reported knee-specific symptoms.

RESULTS: Seven hundred ninety-eight patients were included in the study. A total of 532 (67%) patients were treated conservatively, and 266 (33%) patients underwent surgery. The mean age at the time of fracture was 66.8, ranging from 6 to 103 years of age. The mean follow-up time was 6.4 years, ranging from 1.1 to 12.3 years follow-up. Overall, the rate of complications was 26%. Overall, the rate of complication for the surgical group was 57% and for the conservative group 4%. The most common early complication was the loss of reduction followed by the removal of symptomatic hardware. The most common late complication was the removal of symptomatic hardware and knee arthroscopy. In all the five KOOS subscales (Pain, Symptoms, ADL, Sport/Rec, and QOL), patients presenting with early and late complications reported statistically significantly worse scores than those without complications.

CONCLUSION: The overall incidence of complications in patients presenting with a patella fracture was 26%, with a mean follow-up time of 6.4 years. In the surgical group, 57% of patients experience at least one complication during the follow-up period. Early and late complications were significantly associated with worse KOOS subscale  scores.