Clinical outcomes of osteosynthesis of well-fixed periprosthetic proximal tibial fractures (Felix type 2A) after total knee arthroplasty

Abstract

Aims: This study aimed to evaluate the clinical and radiologic outcomes of well-fixed periprosthetic tibial fractures after TKA. Patients and methods: The medical records of patients who presented with Felix type 2A periprosthetic tibial fractures after TKA between March 2015 and February 2020 were retrospectively obtained from 5 institutions. Data on injury mechanism, fracture pattern including open fractures and Felix classification, and surgical method were recorded. Functional outcomes including range of motion (ROM) and Knee So-ciety Score (KSS) at postoperative 1 year were reviewed. The need for reoperation was also reviewed. Radiologic findings included union time and mechanical proximal tibial angle (MPTA) at the last radio-logic follow-up. Results: Eighteen patients (13 women, 5 men; average age, 73.9 years) were included. The average follow-up duration was 20.8 months. The fractures resulted from high-energy (11 cases) and low-energy (7 cases) injuries. Two cases involved open fractures. Anatomical locking plates were used in all cases: single plate (4 cases) and dual plates (14 cases). The average number of proximal screws was 7.1 (range, 4-9). All patients achieved bone union at an average of 18.6 weeks without secondary intervention. No infection occurred; however, 1 patient with skin necrosis required local flap. Implant removal was performed in 5 cases: 1 case, skin defect and 4 cases, discomfort due to plate prominence. The average ROM and KSS were 120.3 degrees and 85.9, respectively. The mean MPTA was 87.8 degrees; the MPTA was higher in the single-plate group (94.0 degrees vs. 88.1 degrees, p = 0.013). Three cases involved values beyond the normal MPTA range (85-90 degrees): 104 degrees and 96 degrees with a single plate and 92 degrees with dual plates. The malalignment rate was higher in the single-plate group ( p = 0.043). Conclusion: Felix type 2A periprosthetic tibial fractures treated with minimally invasive osteosynthesis showed excellent clinical outcomes, and tibial alignment was well maintained in the dual-plate group. (c) 2021 Elsevier Ltd. All rights reserved.