Aims. Surgical treatment of hip fracture is challenging; the bone is porotic and fixation failure can be catastrophic. Novel implants are available which may yield superior clinical outcomes. This study compared the clinical effectiveness of the novel X-Bolt Hip System (XHS) with the sliding hip screw (SHS) for the treatment of fragility hip fractures. Methods. We conducted a multicentre, superiority, randomized controlled trial. Patients aged 60 years and older with a trochanteric hip fracture were recruited in ten acute UK NHS hospitals. Participants were randomly allocated to fixation of their fracture with XHS or SHS. A total of 1,128 participants were randomized with 564 participants allocated to each group. Participants and outcome assessors were blind to treatment allocation. The primary outcome was the EuroQol five-dimension five-level health status (EQ-5D-5L) utility at four months. The minimum clinically important difference in utility was pre-specified at 0.075. Secondary outcomes were EQ-5D-5L utility at 12 months, mortality, residential status, mobility, revision surgery, and radiological measures. Results. Overall, 437 and 443 participants were analyzed in the primary intention-to-treat analysis in XHS and SHS treatment groups respectively. There was a mean difference of 0.029 in adjusted utility index in favour of XHS with no evidence of a difference between treatment groups (95% confidence interval -0.013 to 0.070; p = 0.175). There was no evidence of any differences between treatment groups in any of the secondary outcomes. The pattern and overall risk of adverse events associated with both treatments was similar. Conclusion. Any difference in four-month health-related quality of life between the XHS and SHS is small and not clinically important. There was no evidence of a difference in the safety profile of the two treatments; both were associated with lower risks of revision surgery than previously reported. Cite this article: Bone Joint J 2021;103-B(2):256–263

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