Low early fixation failure rates with variable-angle locking plate fixation of AO/OTA 34 C patella fractures: a retrospective cohort study.

PURPOSE: To determine the fixation failure rate of the variable-angle (VA) locking patella plate and to evaluate whether supplemental augmentation reduced the risk of fixation failure.

METHODS

A retrospective comparative cohort study was performed at a Level I trauma center between January 2021 and June 2025. Adult patients with OTA/AO 34 C patella fractures treated with a VA locking plate with or without augmentation and ≥ 3 months of follow-up were included. Augmentation was defined as additional plates, independent screws, cerclage wire, heavy non absorbable sutures, or suture anchors that were used to supplement fixation and/or reinforce the inferior patellar pole or extensor mechanism. The primary outcome was fixation failure; secondary outcomes included mode of failure, infection and symptomatic implant removal.

RESULTS

Thirty-four patients were included (17 VA-only, 17 VA + augmentation). Groups were comparable for age, sex, Charlson Comorbidity Index, OTA/AO subclassification, open fracture status and follow-up duration (all p > 0.05). The overall fixation failure rate was 2.9% (1/34), occurring at the distal fixation interface in the augmented group. There was no significant difference in failure rate between groups (VA-only 0.0% vs. VA + augmentation 5.9%; p = 1.0). One patient in the VA group suffered a fracture-related infection and one patient in the VA + augmentation cohort had a suture abscess. One patient in the VA + augmentation cohort required hardware removal for symptomatic hardware. All remaining patients healed without complications.

CONCLUSION

Variable-angle locking plate fixation of AO/OTA 34 C patella fractures was associated with low rates of early fixation failure and symptomatic hardware removal. With only a single documented fixation failure, the study was underpowered to draw conclusions regarding the protective role of augmentation on fixation failure.