Implant choice was changed from cemented Thompson to Exeter Trauma Stem (ETS) for treatment of displaced intra-capsular neck of femur fractures in University Hospital Aintree, Liverpool, United Kingdom (a major trauma center), following the NICE guidelines that advised about the use of a proven femoral stem design rather than Austin Moore or Thompson stems for hemiarthroplasties.

The aim of our study was to compare the results of Thompson versus ETS hemiarthroplasty in Aintree.

We initially compared 100 Thompson hemiarthroplasties that were performed before the start of ETS use, with 100 ETS hemiarthroplasties.

There was no statistically significant difference between the two groups in terms of patients' demographics (age, sex and ASA grade), intra-operative difficulties/complications, post op medical complications, blood transfusion, in-patient stay and dislocations.

The operative time was statistically significantly longer in the ETS group (p= .0067). Worryingly, the 30 days mortality in ETS group was more than three times higher in ETS group (5 in Thompson group versus 16 in ETS group. P= .011).

To corroborate our above findings we studied 100 more consecutive patients that had ETS hemiarthroplasty. The results of this group showed 30 day mortality of 8 percent. However the operative time was again significantly longer (p= .003) and there was 18 percent conversion to bipolar hemiarthropalsty. Moreover there was statistically significant increased rate of deep infection (7%, p = .03) and blood transfusion (27%, p = .007).

This we feel may be due to longer and more surgically demanding operative technique including pressurised cementation in some patients with significant medical comorbidities.

Our results raise the question whether ETS hemiarthoplasty implant is a good implant choice for neck of femur fracture patients. Randomised control trials are needed to prove that ETS implant is any better than Thompson hemiarthroplasty implants in this group of patients.

The position of the pelvis has been shown to influence acetabular orientation. However there have been no studies quantifying that effect on the native acetabulum. Our aims were to investigate whether it is possible to quantify the relationship between pelvic tilt and acetabular orientation in native hips, and whether pelvic tilt affects acetabular cover of the femoral head.

Computerized tomography scans of 93 hips (36 normal, 31 dysplastic and 26 with acetabular retroversion) were analyzed. We used a CT technique that allows standardised three-dimensional (3D) analysis of acetabular inclination and anteversion and calculation of femoral head cover in relation to the anterior pelvic plane and at different degrees of forward and backward tilt. Acetabular anteversion, inclination and cover of the femoral head were measured at pelvic tilt angles ranging from −20° to 20° in relation to the anterior pelvic plane using 5° increments.

The effect of pelvic tilt on version was similar in the normal, dysplastic and retroverted groups, with a drop in anteversion ranging from 2.5° to 5° for every 5° of forward tilt. The effect on inclination was less marked and varied among the three groups. Pelvic tilt increased femoral head cover in both normal and dysplastic hips. The effect was less marked, and tended to be negligible at higher positive tilt angles, in the retroverted group.

This study has provided benchmark data on how pelvic tilt affects various acetabular parameters which in turn may be helpful in promoting greater understanding of acetabular abnormalities and how pelvic tilt affects the interpretation of pelvic radiographs.

Introduction

Through the paediatric LCP Hip plating system, the highly successful technique of the locking compression plate used in adult surgery, has been incorporated in a system dedicated to paediatrics. The purpose of this study was to review the outcome of the paediatric LCP Hip plate use in children, both with and without neuromuscular disease, for fixation of proximal femoral osteotomy for a variety of indications.

The position of the pelvis influences acetabular orientation. In particular, pelvic tilt in the sagittal plane may lead to inaccurate interpretation of plain pelvic radiographs. We therefore quantified the relationship between this pelvic tilt and acetabular orientation in native hips, and determined whether pelvic tilt affects femoral head cover.

We analysed computed tomography scans of 93 hips (36 normal, 31 dysplastic, 26 with acetabular retroversion) and measured acetabular anteversion, inclination, and femoral head cover at pelvic tilt angles ranging from −20° to 20° in relation to the anterior pelvic plane using 5° increments.

The effect of pelvic tilt on version was similar in the normal, dysplastic, and retroverted groups, with a drop in anteversion ranging from 2.5° to 5° for every 5° of forward tilt.

There was a tendency for the inclination angle to decrease when the pelvis was tilted forward from a position of extension, and in normal hips, this produced a reduction in inclination of about 4° for every 8° of pelvic tilt; but once neutral pelvic tilt was reached, further forward rotation of the acetabulum had rather a small effect on the inclination angle.

In normal and dysplastic hips pelvic tilt increased apparent femoral head cover; in the retroverted group the effect was less marked and tended to be negligible at higher tilt angles. Anterior cover increased with increasing forward tilt in all three groups of hips. Posterior cover, on the other hand, decreased by just 2% for the dysplastic hips, 3.5% for the normal hips, and 6% for the retroverted hips over the whole range of tilt from −20° to 20°.

A greater understanding of the influence of pelvic tilt may allow improvements in the radiological diagnosis and surgical treatment of acetabular abnormalities, particularly in relation to acetabular reorientation procedures and femoroacetabular impingement.