High failure rates in comminuted patella fractures (AO/OTA 34-C3) fixed with an isolated new patella specific 2.7 mm variable angle locking plate
Wayne Hoskins, Rown Parola, Charles Gusho, Jaime L. Bellamy, Abdulai Bangura, Gregory Della Rocca, Kyle Schweser, Steven DeFroda, Brett Crist, Douglas HaaseOBJECTIVES:
To compare the outcomes of comminuted patella fractures fixed with a new patella-specific 2.7mm variable angle (VA) locking plate in isolation versus when augmentation of fracture fixation is applied with the plate.
METHODS:
Design:Retrospective
Setting:
Academic Level I Trauma Center.
Patient Selection Criteria:
All acute comminuted patella fractures (AO/OTA 34-C3; complete displaced or undisplaced articular, frontal/coronal multifragmentary fractures) in adult patients primarily treated with a new patella-specific 2.7 mm VA locking plate (Synthes, Paoli, PA) between January 2021 and February 2024 at a single academic center were reviewed and divided in those fixed with the patella plate alone and those with additional bony and/or soft tissue augmentation. Excluded were those with < 90 follow-up, set a priori, unless complications occurred <90 days.
Outcome Measures and Comparisons:
Comparison of patient age, sex, BMI, ASA, FRAX score, open fracture, polytrauma involvement, length of follow-up and post-operative protocols was made between groups. The primary outcome measure was loss of fixation. Secondary outcomes were mode of failure and other surgical complications.
RESULTS:
There were a total of 38 included patients, with no lack of or loss of follow-up, with 20 grouped into patella plate alone, and 18 into patella plate plus augmentation. The plate only group had a higher mean age (63.7 vs. 46.9, p=0.024), with no between-group differences in sex (65% vs. 44% female, p=0.20), BMI (p=0.51), 10-year fracture risk (FRAX) (p=0.06), open fractures (p=0.30), polytrauma involvement (p=0.97), or postoperative weight-bearing (p=0.76) or range of motion (p=0.06) protocols. There were eight failures (40.0%) in the plate-only group, and two failures in the plate with augmentation group (11.1%); (p=0.043). When controlling for known risk factors for osteoporosis and poor bone quality using the FRAX 10-year fracture risk on multivariable regression analysis, plate fixation with fracture augmentation was associated with a lower risk of fixation failure (OR=0.14, 95% CI 0.02-0.75; p=0.036). The plate-only group failed by loss of distal (62.5%,
CONCLUSIONS:
Treatment of comminuted patella fractures with a new patella-specific 2.7mm VA locking plate has a high failure rate when used in isolation. Augmenting fracture fixation with soft-tissue repair and/or independent fracture fragment fixation may significantly decrease failure rates. In particular, augmentation of the tendon avulsion component to restore the extensor mechanism appears critical.
LEVEL OF EVIDENCE:
Therapeutic Level 3