Dear Sir,
I read your article on choosing a THR rather than HA for femoral neck fractures, which coincidentally is the same recommendation as the NICE clinical guidance 124, 2011: Hip Fracture, the management of hip fractures in adults. You highlight that the downside is an increase in the dislocation rate if you choose a THR.
One way to reduce this dislocation rate is to choose a dual mobility cup. The implant consists of a mobile polyethylene (PE) liner that is free to articulate within a polished metal back shell, while the metal head of a stem is also able to articulate within the retentive PE liner. The dual mobility principle significantly increases both the range of movement up to 186°, and forces required for de-coaptation, thus reducing the risk of dislocation (1 in 1100 at the University Hospital of Caen, Aubriot, 1995).
The Novae cup was the first dual mobility cup and studies have demonstrated the excellent clinical results it is able to achieve, with an average of 95% survivorship at 12 years. The studies also recognise the excellent long-term results when used in both primary and revision surgery. The Novae cup was developed in France in 1975 by Professor Gilles Bousquet and engineer André Rambert. It currently has achieved an ODEP rating of 10B.
I hope your readers may find this information of interest.
Matthew Walker, BSc (Hons), DipM , Marketing Manager, Orthodynamics Ltd, Industrial Park, Bourton on the Water, Gloucestershire GL54 2HQ, UK.
Editor-in-Chief’s comment:
We agree at 360 that dual mobility cups offer a tantalising option for these difficult-to-treat, high performance hip fracture patients. Quite by chance in this month’s 360 we report on a study of a dual mobility cup, although in this case used for acetabular revisions. We agree that the theory is sound although we were unable to find any studies with follow-up to 12 years for the Novae cup on PubMed, and no data surrounding use in hip fracture. However, we would love to see the results of a dual mobility cup in a properly conducted study. We think they might be very encouraging indeed.
