Dual mobility cups have two points of articulation, one between the shell and the polyethylene (external bearing) and one between the polyethylene and the femoral head (internal bearing). Movement occurs at the inner bearing; the outer bearing only moves at extremes of movement. Dislocation after total hip arthroplasty (THA) is a cause of much morbidity and its treatment has significant cost implications. Dual mobility cups provide an increased range of movement and a may reduce the risk of dislocation. . This paper reviews the use of these cups in THA, particularly where stability is an issue. Dual mobility cups may be of benefit in primary THA in patients at a high risk of dislocation, such as those who are older with increased comorbidities and a higher American Association of Anesthesiology grade and those with a neuromuscular disease. They may be used at revision surgery where the risk of dislocation is high, such as in patients with many prior dislocations, or those with abductor deficiency. They may also be used in THA for displaced fractures of the femoral neck, which has a notoriously high rate of dislocation. Cite this article: Bone Joint J 2016;98-B(1 Suppl A):60–3

Aims. Dislocation remains a significant complication after total hip arthroplasty (THA), being the third leading indication for revision. We present a series of acetabular revision using a dual mobility cup (DMC) and compare this with our previous series using the posterior lip augmentation device (PLAD). Methods. A retrospective review of patients treated with either a DMC or PLAD for dislocation in patients with a Charnley THA was performed. They were identified using electronic patient records (EPR). EPR data and radiographs were evaluated to determine operating time, length of stay, and the incidence of complications and recurrent dislocation postoperatively. Results. A total of 28 patients underwent revision using a DMC for dislocation following Charnley THA between 2013 and 2017. The rate of recurrent dislocation and overall complications were compared with those of a previous series of 54 patients who underwent revision for dislocation using a PLAD, between 2007 and 2013. There was no statistically significant difference in the mean distribution of sex or age between the groups. The mean operating time was 71 mins (45 to 113) for DMCs and 43 mins (21 to 84) for PLADs (p = 0.001). There were no redislocations or revisions in the DMC group at a mean follow-up of 55 months (21 to 76), compared with our previous series of PLAD which had a redislocation rate of 16% (n = 9) and an overall revision rate of 25% (n = 14, p = 0.001) at a mean follow-up of 86 months (45 to 128). Conclusion. These results indicate that DMC outperforms PLAD as a treatment for dislocation in patients with a Charnley THA. This should therefore be the preferred form of treatment for these patients despite a slightly longer operating time. Work is currently ongoing to review outcomes of DMC over a longer follow-up period. PLAD should be used with caution in this patient group with preference given to acetabular revision to DMC. Cite this article: Bone Joint J 2020;102-B(4):423–425

Aims. With increasing burden of revision hip arthroplasty (THA), one of the major challenges is the management of proximal femoral bone loss associated with previous multiple surgeries. Proximal femoral arthroplasty (PFA) has already been popularized for tumour surgeries. Our aim was to describe the outcome of using PFA in these demanding non-neoplastic cases. Methods. A retrospective review of 25 patients who underwent PFA for non-neoplastic indications between January 2009 and December 2015 was undertaken. Their clinical and radiological outcome, complication rates, and survival were recorded. All patients had the Stanmore Implant – Modular Endo-prosthetic Tumour System (METS). Results. At mean follow-up of 5.9 years, there were no periprosthetic fractures. Clearance of infection was achieved in 63.6% of cases. One hip was re-revised to pseudo arthroplasty for deep infection. Instability was noted in eight of the hips (32%), of which seven needed further surgery. Out of these eight hips with instability, five had preoperative infection. Deep infection was noted in five of the hips (20%), of which four were primarily revised for infection. One patient had aseptic loosening of the femoral component and awaits revision surgery. The Kaplan-Meier survivorship free of revision of any component for any reason was 72% (95% confidence interval (CI) 51.3% to 92.7%), and for revisions of only femoral component for any reason was 96% (95% CI 86.3% to 105.7%) at five years. Conclusion. Dislocation and infection remain the major cause for failure, particularly in patients with pre-existing infection. The use of dual mobility cups, silver-coated implants, and less aggressive postoperative rehabilitation regimens would possibly aid in the reduction of complications. PFA performed in patients with periprosthetic fracture seem to fair better. This study supports the judicious use of PFA in non-oncological revision hip arthroplasties, and that they be performed by experienced revision arthroplasty surgeons. Cite this article: Bone Jt Open 2022;3(3):229–235

Aims

One-stage revision hip arthroplasty for periprosthetic joint infection (PJI) has several advantages; however, resection of the proximal femur might be necessary to achieve higher success rates. We investigated the risk factors for resection and re-revisions, and assessed complications and subsequent re-revisions.

We evaluated the accuracy with which a custom-made acetabular component could be positioned at revision arthroplasty of the hip in patients with a Paprosky type 3 acetabular defect.

A total of 16 patients with a Paprosky type 3 defect underwent revision surgery using a custom-made trabecular titanium implant. There were four men and 12 women with a median age of 67 years (48 to 79). The planned inclination (INCL), anteversion (AV), rotation and centre of rotation (COR) of the implant were compared with the post-operative position using CT scans.

A total of seven implants were malpositioned in one or more parameters: one with respect to INCL, three with respect to AV, four with respect to rotation and five with respect to the COR.

To the best of our knowledge, this is the first study in which CT data acquired for the pre-operative planning of a custom-made revision acetabular implant have been compared with CT data on the post-operative position. The results are encouraging.

Cite this article: Bone Joint J 2015; 97-B:780–5.