Revision hip arthroplasty presents a challenge in the setting of femoral bone loss. Tapered stems are susceptible to subsidence which leads to leg length inequality, hip instability and may necessitate repeat femoral revision surgery.

The purpose of this study was to compare radiographic outcomes in two modular tapered revision systems with different distal stem geometries. We sought to establish the minimum postoperative stem bi-cortical contact length that predicts subsidence for tapered stems.

This study examined revision total hip arthroplasties between 2009 and 2016 in a European university affiliated major trauma center. Modular stem A has a taper of 3 degrees whereas modular stem B has a taper of 2 degrees. Radiologic assessment compared x-rays at two time points: immediately post-surgery and most recent x-ray available at a minimum follow up of two years. Leg length discrepancy, subsidence and postoperative bi cortical contact was assessed. Descriptive summary statistics calculated clinical factors (i.e. age, gender, Paprosky classification).

122 arthroplasties were completed. Complete data was available for 112. Revisions were carried out for Paprovski grade 3a/ 3b femoral deficits. Post-operative bi-cortical contact of the proximal stem < 20mm was associated with higher subsidence rates (P = 0.047). Subsidence rates for implant A and B system were 4.27mm (0.12–25.62mm) and 3.43 mm (0.3–11.1 mm) respectively. Significant subsidence was noted in 9.8% (n=8) in implant A and 5.2%(n=2) in implant B.

We conclude that immediate postoperative bi-cortical stem contact of <20mm was associated with significantly higher subsidence rates in this study.

This study reports on the natural history of acetabular fracture dislocations. We retrospectively reviewed patients who sustained an acetabular fracture associated with a posterior hip dislocation from a prospective database. Patient characteristics, complications and the requirement for further surgery were recorded. Patient outcomes were measured using the Oxford Hip score and Short Form SF-12 health survey.

A total of 99 patients were treated over a 24 year period. The mean age was 41 years. Open reduction and internal fixation was performed in the majority (n=87), 10 were managed conservatively following closed reduction and two underwent primary total hip replacement (THR). At a median follow up of 12.4 years (range 4–24 years) patient outcomes were available for 53 patients. 12 patients had died. 19 patients went onto have a THR as a secondary procedure, of which 11 had confirmed avascular necrosis. Median time to THR was 2 years (range 1–17 years). The mean Oxford hip score was 35 (range 2–48), SF-12 physical component score (PCS) was 40 and a third of the patients used a walking aid. In THR group the mean Oxford score was 32 (range 3–46), SF-12 PCS was 39 and almost all required a walking aid.

This is the first study to present the long term outcomes following an acetabular fracture dislocation. Our study suggests there is considerable disability in this group of patients and the requirement for subsequent THR has inferior patient reported outcomes.

The spiral blade modification of the Dynamic Hip Screw (DHS) was designed for superior biomechanical fixation in the osteoporotic femoral head. Our objective was to compare clinical outcomes and in particular the incidence of loss of fixation.

In a series of 197 consecutive patients over the age of 50 years treated with DHS-blades (blades) and 242 patients treated with conventional DHS (screw) for AO/OTA 31.A1 or A2 intertrochanteric fractures were identified from a prospectively compiled database in a level 1 trauma centre. Using propensity score matching, two groups comprising 177 matched patients were compiled and radiological and clinical outcomes compared. In each group there were 66 males and 111 females. Mean age was 83.6 (54 to 100) for the conventional DHS group and 83.8 (52 to 101) for the blade group.

Loss of fixation occurred in two blades and 13 DHSs. None of the blades had observable migration while nine DHSs had gross migration within the femoral head before the fracture healed. There were two versus four implant cut-outs respectively and one side plate pull-out in the DHS group. There was no significant difference in mortality and eventual walking ability between the groups. Multiple logistic regression suggested that poor reduction (odds ratio (OR) 11.49, 95% confidence intervals (CI) 1.45 to 90.9, p = 0.021) and fixation by DHS (OR 15.85, 95%CI 2.50 to 100.3, p = 0.003) were independent predictors of loss of fixation.

The spiral blade design may decrease the risk of implant migration in the femoral head but does not reduce the incidence of cut-out and reoperation. Reduction of the fracture is of paramount importance since poor reduction was an independent predictor for loss of fixation regardless of the implant being used.

Cite this article: Bone Joint J 2015;97-B:398–404.

Introduction

Femur neck fractures (NOF) in the young could result in mal-union, non-union and avascular necrosis of the femoral head. Osteosynthesis is the standard of management in NOFs in young patient above complications sometimes end in Arthroplasty. The aim of our study is to identify predictors of NOF failures in the young population.

Introduction

Anterior knee pain is a common presentation of patello-femoral dysfunction and patients with this disorder represent a significant proportion attending a specialist knee clinic. There is an on-going debate as to the cause and best treatment for such patients. Previous studies on patella-femoral morphology have suggested patella maltracking plays an important part in the aetiology but there had been no studies correlating maltracking with articular cartilage change.

We carried out a retrospective review over ten months of patients who had presented with a low-energy subtrochanteric fracture. We identified 13 women of whom nine were on long-term alendronate therapy and four were not. The patients treated with alendronate were younger, with a mean age of 66.9 years (55 to 82) vs 80.3 years (64 to 92) and were more socially active. The fractures sustained by the patients in the alendronate group were mainly at the femoral metaphyseal-diaphyseal junction and many had occurred after minimal trauma. Five of these patients had prodromal pain in the affected hip in the months preceding the fall, and three demonstrated a stress reaction in the cortex in the contralateral femur.

Our study suggests that prolonged suppression of bone remodelling with alendronate may be associated with a new form of insufficiency fracture of the femur. We believe that this finding is important and indicates the need for caution in the long-term use of alendronate in the treatment of osteoporosis.