Outcome Scores & National Registries

Surgical Outcomes

The starting point for a good outcome is an accurate diagnosis and appropriate treatment. This cannot be overstated. When discussing a knee problem with a patient the questions I might expect as a surgeon are:

“What are my options (for treatment)?”

If all non-operative options have previously been considered …

“What are my surgical options (given my age and lifestyle)?”

If specific surgical procedures are discussed …

“How many of these procedures have you done?”

“What are your results (outcomes)?”

Whilst this may be difficult for some patients to ask it does form part of both the ‘treatment plan’ and the patient consent process which is closely linked to the ultimate outcome.

There are many things which can affect the outcome besides the surgical ‘performance’ so any numerical outcome scoring system must be interpreted in context. The information given to the patient before the procedure and the manner in which it is given will significantly affect the patient’s expectation; the patient’s experience of the delivery of that ‘care episode’; his/her post-operative care and support (including the adequate provision of physiotherapy) and any complications relating to the procedure will all have an influence on any numerical ‘mark’ ascribed to the outcome. Although not perfect these outcome scores are currently our best ‘bench marking’ tools. It is mandatory to submit data to the National Joint Registry which covers Unicompartmental and Total Knee Replacement, but the other newer / ‘emerging’ registries - National Ligament Registry and UK Knee Osteotomy Registry - are not yet mandated and the take up by surgeons remains an issue.

Whilst the outcome of any surgical procedure is obviously important to the patient it should also matter to:

  • The surgeon (self-reflection and Appraisal)
  • The involved hospital (Provision of Quality care)
  • Any organisation / company who may be responsible for the funding of that procedure (cost effectiveness)

How we record and report the outcome is a constantly evolving specialty. Historically Orthopaedic outcomes were recorded by observing the movements, complications or x-ray findings (objective measures). The issue was that they often did not reflect patient function or perception. As a result, most procedures now have their outcome recorded by Patient Reported Outcome Measures (PROMs) – specific questionnaires which report on either the general health (generic) of the patient or the ‘joint specific’ functional outcome.


A registry is a large database - which will contain some patient personal details - established to acquire certain outcome information about a specific procedure or group of similar procedures. The longest established Registry in the UK is for joint replacement: The National Joint Registry (NJR). This was established by the department of Health and Welsh Government in 2002 in response to an earlier problem with a commonly used hip replacement. It reports on the survivorship of the prostheses we use for hip, knee, shoulder elbow and ankle replacements.

The 4 ‘major’ knee procedures which are commonly undertaken and the relevant registries which have been established to record outcome information on each of these are:

  1. Total Knee Replacement (National Joint Registry)
  2. Unicompartmental Knee Replacement (National Joint Registry)
  3. Anterior Cruciate Ligament Reconstruction (National Ligament Registry)
  4. Osteotomy (UK Knee Osteotomy Registry)

National PROMs programme

Patient Reported Outcome Measures (PROMs) measure health gain in NHS patients undergoing hip replacement and knee replacement surgery in England, based on responses to questionnaires before and after surgery.

This provides an indication of the outcomes or quality of care delivered to NHS patients and has been collected by all providers of NHS-funded care since April 2009.