Scores of patients in Hillingdon are being denied knee surgery referrals every year because they are overweight, in defiance of NHS guidelines, according to a watchdog group.
The Hillingdon Hospitals NHS Foundation Trust says that annually only around 'half a dozen' of its patients are not referred to a surgeon to discuss knee replacement because they have a Body Mass Index (BMI) higher than 40.
But Healthwatch Hillingdon, a group that monitors health services in the borough, estimates that the true number is closer to 60. Raj Grewal, the group's operations coordinator, said this discrepancy existed because when patients are not referred for surgery, the reasons are often not recorded.
The weight restriction goes against National Institute for Health and Care Excellence (NICE) guidelines, which say obesity should not be a barrier to referral for joint surgery, although it may be a legitimate reason for not having the surgery itself. NICE guidelines, however, are not legally enforceable.
Mr Grewal said: “We think NICE guidelines are there for a reason: they are based on good, clinical evidence of outcomes. And because they are national guidelines we expect that care to be provided to the residents of Hillingdon."
He added: “When you are overweight there is an element of additional risk in any procedure. We accept that. But it should be up to an individual to come to their own decision, together with a medical professional, rather than a policy which bans it outright.”
The BMI restriction for knee operations is used by all eight Clinical Commissioning Groups (CCGs) responsible for NHS services in north-west London, together known as the NWL CCGs.
In some other parts of the UK, however, no such restriction exists.
And in north-west London, the same restriction does not apply to other, similar surgeries, such as hip replacements.
Mr Grewal said: “I cannot see any valid reason why [the restriction] is there. In the absence of any clinical evidence for a restriction, then the only criteria is financial.”
The NWL CCGs said the policy would be reconsidered.
Spokeswoman Catherine Brown said: “The NWL CCGs have a joint Planned Procedure with a Threshold Policy (PPwT) on knee replacement surgery, which was based on an assessment of the likelihood of a successful surgical outcome, that requires patients to have a BMI under 40 in order to be eligible for surgery.
“The NWL CCGs will consider this threshold when reviewing the PPwT policies for North West London for 2015/16.”
Every year around 300 knee replacement surgeries are completed in Hillingdon, at an average cost of around £3,600, according to borough's NHS trust, although this figure can rise significantly if there are complications.