Unicompartmental knee replacement in a district general hospital

Smith, Lindsay K; Wong, J.; Cowie, Simon; Radford, Michael; Price, Mark; Langkamer, V.G.

Abstract

Abstract
Unicompartmental knee replacement has been associated with a higher revision rate than total knee replacement in all national joint registers. It has been suggested that the appropriate training of surgeons to perform this arthroplasty is an important factor for implant survival. We investigated the outcome of all unicompartmental knee arthroplasty completed in a district general hospital over a ten year period in order to inform our local practice.

Methods
Theatre log books were examined by a consultant orthopaedic surgeon to identify all patients who had received a unicompartmental knee replacement at Weston General Hospital between April 2003 and May 2013. Any type of revision for knee arthroplasty in the same period was also recorded. The revision of any UKR was identified, with subsequent retrieval of medical notes to obtain further details.

All patients with UKR and no known revision were contacted by letter or phone call to ascertain the outcome of their UKR. In cases where no contact was made, the GP was consulted. The study was registered as a clinical audit with the local NHS Trust.

Data were analysed using the life table method in three categories: all surgeons and all types of UKR, all surgeons using only Oxford UKR, and surgeons specifically trained for Oxford UKR.

Results
Over the ten year period, 319 UKR were completed in this orthopaedic unit and there was one loss to follow up. Four different types of UKR were included and there were 21 failures with a 5 year survival of 91.54%. The number of mobile bearing Oxford UKR completed was 310 with 17 failures and a 5 year cumulative survival rate of 93.56%. The number of Oxford UKR completed only by surgeons specifically trained for this arthroplasty was 242, with 10 failures and a five year cumulative survival of 95.68%.

Discussion
In the 10th annual report of the National Joint Registry of England, Wales and Northern Ireland, the cumulative probability for first revision at five years for all UKR was 7.06% (6.78 – 7.34 95%CI) and for Oxford partial knee was 6.61% (6.30-6.95 95%CI). Our results for surgeons specifically trained to use the Oxford UKR are at least comparable with, if not better than, the NJR and support continued use of this prosthesis in a non-specialist centre as long as the surgeons are appropriately trained.

Acknowledgements
Ms. Jenny Wong, Medical student
Mr. Simon Cowie, Orthopaedic Registrar
Mr. M.N. Shannon, Consultant Orthopaedic Surgeons

NBT for lateral UKR: 95.5% at 5 years
Oxford UKR with minimally invasive approach: 97.5%

• Journal Article Type: Article
• Conference Name: South West Orthopaedic Club Conference
• Start Date: Nov 21, 2014
• End Date: Nov 21, 2014
• Publication Date: Nov 21, 2015
• Publicly Available Date: Jun 5, 2019
• Journal: Orthopaedic Proceedings
• Electronic ISSN: 2049-4416
• Publisher: British Editorial Society of Bone and Joint Surgery
• Peer Reviewed: Peer Reviewed
• Volume: 97-B
• Issue: 7
• Keywords: knee arthroplasty, replacement, unicompartmental survival
• Public URL: https://uwe-repository.worktribe.com/output/802944
• Publisher URL: http://www.bjjprocs.boneandjoint.org.uk/content/97-B/SUPP_7/14
• Additional Information: Title of Conference or Conference Proceedings : Orthopaedic Proceedings, The Bone & Joint Journal