Aims. There are concerns regarding nail/medullary canal mismatch and initial stability after cephalomedullary nailing in unstable pertrochanteric fractures. This study aimed to investigate the effect of an additional anteroposterior blocking screw on fixation stability in unstable pertrochanteric fracture models with a nail/medullary canal mismatch after short cephalomedullary nail (CMN) fixation. Methods. Eight finite element models (FEMs), comprising four different femoral diameters, with and without blocking screws, were constructed, and unstable intertrochanteric fractures fixed with short CMNs were reproduced in all FEMs. Micromotions of distal shaft fragment related to proximal fragment, and stress concentrations at the nail construct were measured. Results. Micromotions in FEMs without a blocking screw significantly increased as nail/medullary canal mismatch increased, but were similar between FEMs with a blocking screw regardless of mismatch. Stress concentration at the nail construct was observed at the junction of the nail body and lag screw in all FEMs, and increased as nail/medullary canal mismatch increased, regardless of blocking screws. Mean stresses over regions of interest in FEMs with a blocking screw were much lower than regions of interest in those without. Mean stresses in FEMs with a blocking screw were lower than the yield strength, yet mean stresses in FEMs without blocking screws having 8 mm and 10 mm mismatch exceeded the yield strength. All mean stresses at distal locking screws were less than the yield strength. Conclusion. Using an additional anteroposterior blocking screw may be a simple and effective method to enhance fixation stability in unstable pertrochanteric fractures with a large nail/medullary canal mismatch due to osteoporosis. Cite this article: Bone Joint Res 2022;11(3):152–161

Objectives. The Sliding Hip Screw (SHS) is commonly used to treat trochanteric hip fractures. Fixation failure is a devastating complication requiring complex revision surgery. One mode of fixation failure is lag screw cut-out which is greatest in unstable fracture patterns and when the tip-apex distance of the lag screw is > 25 mm. The X-Bolt Dynamic Hip Plating System (X-Bolt Orthopaedics, Dublin, Ireland) is a new device which aims to reduce this risk of cut-out. However, some surgeons have reported difficulty minimising the tip-apex distance with subsequent concerns that this may lead to an increased risk of cut-out. Patients and Methods. We measured the tip-apex distance from the intra-operative radiographs of 93 unstable trochanteric hip fractures enrolled in a randomised controlled trial (Warwick Hip Trauma Evaluation, WHiTE One trial). Participants were treated with either the sliding hip screw or the X-Bolt dynamic hip plating system. We also recorded the incidence of cut-out in both groups, at a median follow-up time of 17 months. Results. There was a significantly increased tip-apex distance with the use of the X-Bolt (mean difference 3.7mm (95% confidence interval 1.58 to 5.73); SHS mean 17.1 mm, X-Bolt mean 20.8; p = 0.001. However, this was not associated with an increased incidence of cut-out at a median follow-up time of 17 months, with three cut-outs (6%) in the SHS group and 0 (0%) in the X-Bolt group. Conclusion. The X-Bolt is a safe implant with no increased risk for cut-out. Concerns about minimising the tip-apex distance may be justified but do not appear to be clinically important. Cite this article: M. A. Fernandez, A. Aquilina, J. Achten, N. Parsons, M. L. Costa, X. L. Griffin. The tip-apex distance in the X-Bolt dynamic plating system. Bone Joint Res 2017;6:–207. DOI: 10.1302/2046-3758.64.BJR-2015-0016.R2

Objectives. Because of the contradictory body of evidence related to the potential benefits of helical blades in trochanteric fracture fixation, we studied the effect of bone compaction resulting from the insertion of a proximal femoral nail anti-rotation (PFNA). . Methods. We developed a subject-specific computational model of a trochanteric fracture (31-A2 in the AO classification) with lack of medial support and varied the bone density to account for variability in bone properties among hip fracture patients. Results. We show that for a bone density corresponding to 100% of the bone density of the cadaveric femur, there does not seem to be any advantage in using a PFNA with respect to the risk of blade cut-out. On the other hand, in a more osteoporotic femoral head characterised by a density corresponding to 75% of the initial bone density, local bone compaction around the helical blade provides additional bone purchase, thereby decreasing the risk of cut-out, as quantified by the volume of bone susceptible to yielding. Conclusions. Our findings indicate benefits of using a PFNA over an intramedullary nail with a conventional lag screw and suggest that any clinical trial reporting surgical outcomes regarding the use of helical blades should include a measure of the femoral head bone density as a covariable

Aims

This study aimed to establish the optimal fixation methods for calcaneal tuberosity avulsion fractures with different fragment thicknesses in a porcine model.

Aims

In this study, we aimed to explore surgical variations in the Femoral Neck System (FNS) used for stable fixation of Pauwels type III femoral neck fractures.

Aims

To draw a comparison of the pullout strengths of buttress thread, barb thread, and reverse buttress thread bone screws.

Objectives

The paradoxical migration of the femoral neck element (FNE) superomedially against gravity, with respect to the intramedullary component of the cephalomedullary device, is a poorly understood phenomenon increasingly seen in the management of pertrochanteric hip fractures with the intramedullary nail. The aim of this study was to investigate the role of bidirectional loading on the medial migration phenomenon, based on unique wear patterns seen on scanning electron microscopy of retrieved implants suggestive of FNE toggling.

Objectives

The monitoring of fracture healing is a complex process. Typically, successive radiographs are performed and an emerging calcification of the fracture area is evaluated. The aim of this study was to investigate whether different bone healing patterns can be distinguished using a telemetric instrumented femoral internal plate fixator.

Objectives

The use of two implants to manage concomitant ipsilateral femoral shaft and proximal femoral fractures has been indicated, but no studies address the relationship of dynamic hip screw (DHS) side plate screws and the intramedullary nail where failure might occur after union. This study compares different implant configurations in order to investigate bridging the gap between the distal DHS and tip of the intramedullary nail.

Fractures of the proximal femur are one of the greatest challenges facing the medical community, constituting a heavy socioeconomic burden worldwide. Controversy exists regarding the optimal treatment for patients with unstable trochanteric proximal femoral fractures. The recognised treatment alternatives are extramedullary fixation usually with a sliding hip screw and intramedullary fixation with a cephalomedullary nail. Current evidence suggests that best results and lowest complication rates occur using a sliding hip screw. Complications in these difficult fractures are relatively common regardless of type of treatment. We believe that a novel device, the X-Bolt dynamic plating system, may offer superior fixation over a sliding hip screw with lower reoperation risk and better function. We therefore propose to investigate the clinical effectiveness of the X-bolt dynamic plating system compared with standard sliding hip screw fixation within the framework of a the larger WHiTE (Warwick Hip Trauma Evaluation) Comprehensive Cohort Study.

Cite this article: Bone Joint Res 2013;2:206–9.

Introduction

The objective of this study was to determine if a synthetic bone substitute would provide results similar to bone from osteoporotic femoral heads during in vitro testing with orthopaedic implants. If the synthetic material could produce results similar to those of the osteoporotic bone, it could reduce or eliminate the need for testing of implants on bone.