Anterior variable-angle locked plating versus tension band wiring of simple and complex patella fractures – a biomechanical investigation

Abstract

Background The aim of this study was to investigate the biomechanical performance of novel anterior variable-angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. Methods Sixteen pairs of human cadaveric knees were used to simulate two-part simple transverse AO/OTA 34-C1 and five-part complex AO/OTA 34-C3 patella fractures. The complex fracture pattern was characterized with a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral and an inferior fragment mimicking comminution around the distal patella pole. Eight pairs with simple fractures were split for fixation via either tension band wiring (TBW) through two parallel cannulated screws or anterior variable-angle locked plating, whereas other eight pairs with complex fractures were split for either TBW through two parallel cannulated screws plus circumferential cerclage wiring, or anterior variable-angle locked plating using a cortical caudo-cranial polar screw. Each specimen was tested over 5000 cycles with a range of motion from 90° flexion to full extension by pulling on the quadriceps tendon. Interfragmentary movements were captured by motion tracking. Results For both fracture types, the longitudinal and shear articular displacements, measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following anterior variable-angle locked plating versus TBW, p ≤ 0.01. Conclusions From a biomechanical perspective, anterior locked plating of both simple and complex patella fractures resulted in less interfragmentary displacement under extended cyclic loading.

Comparative study of locking neutralization plate construct versus tension band wiring with a cannulated screw for patella fractures: experimental and finite element analysis

“…Fixed-angle plates, in particular, have been proven to provide better biomechanical support and reduce the widening of fractures during movement compared to using cannulated screws with the VA LNP technique [ 29 ]. Recent designs of VA LNP are believed to offer enhanced adjustability and stability [ 13 , 14 , 30 ]. Stoffel et al studied the effectiveness of using TBW versus using VA LNP in cadaver tests, and the VA LNP approach showed significantly less displacement after cycling compared to the tension band wiring method [ 14 ].…”

“…Recent designs of VA LNP are believed to offer enhanced adjustability and stability [ 13 , 14 , 30 ]. Stoffel et al studied the effectiveness of using TBW versus using VA LNP in cadaver tests, and the VA LNP approach showed significantly less displacement after cycling compared to the tension band wiring method [ 14 ]. Similar findings were reported by Kfuri et al [ 30 ] However, there is a lack of data on the effectiveness of these VA LNPs for simple transverse patella fractures.…”

“…Bilateral VA LNP plating has demonstrated reduced interfragmentary displacement and higher failure loads compared to other methods under cyclic loading conditions [ 11 , 12 ]. Moreover, VA LNP provides increased adjustability and stability of screw heads, offering improved outcomes compared to TBW [ 13 , 14 ].…”

A novel suture bridge anchor fixation technique to treat inferior pole fractures of patella: A retrospective clinical study

“…are the preferred surgical treatments for inferior pole fractures of patella. [8,9] Resection of the inferior pole of patella is rarely applied at present because it changes the biomechanical characteristics of the patella, causes weakened quadriceps muscle strength and patellofemoral arthritis and affects the function of the knee joint. In contrast, Kirschner wire tension band internal fixation is widely applied.…”