Evaluation of Two Types of Intramedullary Jones Fracture Fixation in a Cyclic and Ultimate Load Model

Abstract

Implant choice is a matter of concern in athletes and active patients who sustain a Jones fracture because they are prone to failure including non‐union, screw failure, and refracture. The aim of this study was to compare the biomechanical behavior of a Jones fracture‐specific screw (JFXS) with a cannulated headless compression screw (HCS) in a simulated partial weight‐bearing and ultimate load Jones fracture fixation model. Ten matched pairs of human anatomical specimens underwent Jones fracture creation and consecutive intramedullary stabilization with a solid JFXS or a cannulated HCS. The bone mineral density was assessed prior to testing. Cyclic plantar to dorsal loading was applied for 1000 cycles, followed by load to failure testing. Angulation was measured by an opto‐electronic motion capture system and mode of failure classification was determined by video analysis. Paired analysis showed no statistically significant difference between both screw constructs. Ultimate load reached 236.9 ± 107.8 N in the JFXS group compared with 210.8 ± 150.7 N in the HCS group (p = 0.429). The bone mineral density correlated positive with the pooled ultimate load (R = 0.580, p = 0.007) for all constructs and negatively with angulation (R = −0.680, p = 0.002) throughout cyclic loading. Solid fracture‐specific and cannulated headless compression screws provide equal ultimate loads and stiffness for Jones fracture fixation. A low bone mineral density significantly impairs the construct stability and the ultimate load of both intramedullary screw constructs. © 2019 The Authors. Journal of Orthopaedic Research ® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society J Orthop Res 38:911‐917, 2020

Peroneus brevis as source of instability in Jones fracture fixation

“…Third, a biomechanical study can never give a true representation of fracture pattern, in vivo failure, or account for fracture healing. However, observation of the mode of failure of the HCS in the present study showed a consistent pattern with previously published data in terms of a bony cut out of the threads engaged at the proximal fifth metatarsal [22]. Fourth, we had to face technical problems with the cup fixation in the machine vice in one specimen and a mechanical testing machine error in another specimen.…”

“…Most biomechanical Jones fracture studies focused on three-point bending tests, plantar to dorsal loading mechanisms, pull-out tests, and torsional forces acting on the fracture site. [16,[22][23][24][25][26][27][28] Three-point bending test and pull-out do not accurately replicate the type of loads that the screw and bone construct would experience during post-operative weight- 5 Mode of failure distribution FX cup is the metatarsal fracture at the steel cup; FS shaft is the metatarsal fracture at the shaft; prox. cut out is the cut out of the screw head at the proximal aspect of the metatarsal; footprint avulsion is the bony avulsion of the peroneus brevis footprint; plantar distal cut out is the cut out of the screw threads at the plantar distal shaft bearing, as these tests represent a worst-case loading situation.…”

“…Early post-operative active mobilization may challenge the intramedullary stabilized Jones fracture by means of tensile forces which can lead to prolonged bone healing, or even result in early failure [11]. Reported biomechanical Jones fracture studies have used several test setups; however, intramedullary screw constructs have never been tested under dynamic loading of the PBT [22][23][24][25][26][27][28]. Since the type of screw for Jones fracture fixation is still matter of debate, a cannulated screw and a fracture-specific solid screw were compared using a novel biomechanical setup.…”

The Effectiveness of Intramedullary Screw Fixation Using the Herbert Screw for Fifth Metatarsal Stress Fractures in High-Level Athletes

“…Those studies have shown that the 2 screws can provide comparable fixation strength, while compression properties differ. 14,29,40 Clinical results of fracture fixations with these headless screws have been reported mostly for the application to fixation of small bones such as scaphoid fractures, and both screws have attained satisfactory outcomes. 5,8,23 Although favorable results of Acutrak screw fixation for Jones fractures were reported by Nagao et al, 25 corresponding results with use of the Herbert screw have only been reported in a few cases.…”

Jones type fifth metatarsal fracture fixation in athletes: A review and current concept

“…Surgical techniques are common among athletes due to the short time it takes to heal these fractures and the lower possibility of nonunion. Studies by Watson et al [ 19 ], Lareau et al [ 20 ], Willegger et al [ 21 ], and D'Hooghe et al [ 22 ] assert that intramedullary screws and aggressive rehabilitation protocols have become popular among professional athletes seeking to return to the field after experiencing Zone 2-3 fifth metatarsal Jones fractures[ 23 , 24 ]. According to these studies, this technique's main advantage is that it is minimally invasive in addition to the short healing time needed and the accelerated mobility.…”