In the late nineties, a well publicised failure of a brand of joint replacement named the Capital Hip occurred in the UK. Partly as a direct result of this, the government requested the National Institute of Healthcare and Clinical Excellence (NICE) to prepare guidelines and summary recommendations on the use of different brands of hip replacement. This guidance, published in 2000, stated that surgeons should only use devices which had published data, demonstrating a minimum ninety percent survivorship at ten years. This advice was subsequently modified to include newer products that were showing a level of performance consistent with this advice (failure rate of less than one percent per annum).
The National Health Purchasing and Supply Agency (PASA) was given the task of monitoring adherence to these guidelines. It set up a panel of experts which became known as the Orthopaedic Data Evaluation Panel (ODEP). The group is under the chairmanship of Mr Keith Tucker FRCS, an orthopaedic Surgeon from Norwich in the UK, a senior member of the British Hip Society. PASA was subsequently replaced by NHS Supply Chain, who managed and provided administrative support to ODEP until the takeover by the Supply Chain Coordination Limited (SCCL) in 2018.
ODEP meet on a regular basis to review submissions of data from manufacturers. Based upon the quality and quantity of the data, submissions are rated on an A*, A or B basis. In addition, the length of follow up in years is also stated: 3, 5, 7, 10 or 13. Any hip brand which has received an ODEP rating has been assessed by ODEP as being part of an ongoing clinical trial and is showing performance within the guidelines set by NICE. Products which have not received an ODEP rating are listed in the National Joint Registry as being “unclassified” and therefore a potential risk to patients.
It has been brought to the attention of ODEP that a number of regulatory and purchasing agencies are discouraging surgeons from using products that have not received a 10A(*) rating, implying that 10A(*) rated products perform better than other products. This was never the intention of ODEP and is a misunderstanding of the intentions of the system. Products with ratings at 3A(*) , 5A(*) , and 7A(*) are tracking to have outcomes in-line with a 10A(*) rating, and may actually be tracking to have better outcome results than some existing 10A(*) or 13A(*) rated products. Indeed this may also be true of some products achieving a B rating. However usage of these products has not normally been in large enough cohorts for the panel to be certain of this fact and hence the B rating has been assigned in these cases.
ODEP consider that restriction of product usage based solely upon ratings already achieved may be misleading and may deter innovation. Until recently, ODEP has limited its deliberation to total hips. However as a result of lobbying by the orthopaedic profession, knees were added to the system in late 2014.
(Update on Uni Knee Replacement - September 2015) Whilst wishing to maintain a degree of consistency for all ODEP ratings whether they be Hip or Knee so far it has not been possible for ODEP to find way of applying the previously used system to Uni Knee replacement. Below is the considered opinion of BASK: -
“ODEP ratings for TKR and THR implants have been based on a specified number of cases achieving a specific revision rate. Rating of compartmental replacements by the same criteria is problematic. The number of UKR's performed is less than a tenth of TKR's in registries. UKR is performed in a younger cohort of patients and age does affect survivorship data. Thresholds for revision of UKR and TKR have been shown to be different and results of UKR have been shown to be more influenced by factors such as surgeon volume, than TKR. Although there is no exact cut-off number which guarantees good results or inevitably predicts poor results with UKR, the current situation, where many UKR surgeons do less than 5 cases per year, is unlikely to give optimal results for any implant. Until a robust rating system is agreed, we suggest that surgeons base their UKR implant decisions on available published or registry data. We also recommend that they are appropriately trained in the use of their chosen implant and do sufficient numbers of UKR to remain proficient.”
The Hip Panel at work, 4 April 2019