Hip and Knee Replacement Waiting Times Update

Find out about the latest waiting times for hip and knee replacement operations with Dr Foster Health

Hip and knee replacement summary

Elective total hip replacement and total or partial knee replacement surgeries are performed to relieve pain and lack of mobility caused by disease (osteoarthritis, osteoporosis and rheumatoid arthritis, for example) or injury to the hip and knee joints. In hip and knee surgery, the joints are replaced with a prosthetic joint made of metals and plastics. Your new hip and knee joint will give you increased strength, movement and mobility and, once you have healed, you will again be able to take part in everyday activities again.

How common are hip and knee replacement operations?

According to the National Joint Registry (NJR), there are approximately 160,000 total hip and knee replacement procedures performed each year in England and Wales, with the same number of hip and knee joint operations performed.

Hip and knee replacement surgery is available at approximately 400 hospitals in England and Wales, of which one-third are independent and two-thirds NHS. Two-thirds of all hip and knee procedures are funded by the NHS.

NHS Hospitals	2008	Independent Hospitals	2008
Hip procedures	50,520	Hip procedures	23,443
Knee procedures	54,790	Knee procedures	23,749
Total	104,987	Total	46,759

Statistics taken from National Joint Registry Fifth Annual Report

In its fifth Annual Report (calendar year 2007), the NJR recorded 68,950 hip replacement procedures, of which 9.7 per cent were revisions or re-operations. Hip resurfacing accounts for eight per cent of total hip replacements.

Knee replacement procedures totalled 72,480, of which 5.6 per cent were either revision or re-operation procedures. Of all knee replacements procedures 83 per cent were total knee replacements and eight per cent were partial knee replacements.

NHS versus Private hospitals

According to the NJR, of all hip replacement procedures 66 per cent were carried out at NHS hospitals, 24 per cent at independent hospitals, five per cent at NHS treatment centres and five per cent at independent sector treatment centres.

For all knee replacement operations, 67 per cent were undertaken in NHS hospitals, 21 per cent in independent hospitals, five per cent in NHS treatment centres, and seven per cent in independent sector treatment centres (ISTCs).

Waiting times for hip and knee replacement operations

Government targets have gone some way to reducing waiting times, especially for high-volume procedures, such as hip and knee replacements.

Dr Foster Health data show that waiting times for hip and knee by Strategic Health Authority (SHA) have been falling year on year in all regions:

Figure 1

Figure 2

Hospital length of stay for knee and hip replacement surgery

The following graphs show you the average length of stay in hospital after a knee or hip replacement operation according to age group.

Figure 3

Figure 4

Inpatient spell: a patient's stay in hospital, consisting of at least one finished consultant episode (period of care under one consultant/team)

Revision rates for hip and knee replacement

According to the National Joint Registry (NJR), the overall revision rate* following primary hip replacement was 0.6 per cent at one year and 1.2 per cent at three years.

The three-year revision rates were lowest in patients who received cemented prosthesis and highest after hip resurfacing.

Overall revision rates were lower in women (1.1 per cent) than in men (1.4 per cent). However, women have higher revisions rates for resurfacing (3.6 per cent) but lower revision rates for all other prostheses.

Mortality rates for hip and knee replacement

The mortality rate* for all 102,179 first hip replacements carried out between April 1 2003 and September 30 2007 was 0.7 per cent at three months after surgery and 6.2 per cent at three years after surgery.

The mortality rate for all 111,723 first knee replacements (not including patellofemoral replacements) for the same period was 0.5 per cent at three months after surgery and 6.1 per cent at three years after surgery.

Hip replacement prostheses update

Cementless hip replacement procedures now make up around a third of all total hip replacements. The reduction in the proportion of cemented implant procedures fell from 48 per cent in 2006 to 43 per cent in 2007, according to the National Joint Registry (NJR).

Cementless implants attach directly to bone without the use of cement. Most of these types of implant have textured surfaces which encourage new bone to grow into the surface of the prosthesis thereby securing it in place.

Cementless prostheses generally last longer than cemented ones, but can fail if bone growth into the prosthesis does not occur at a sufficient depth to secure the new joint. Another side-effect is that patients with this type of hip prosthesis can sometimes experience mild thigh pain.

Other disadvantages of all hip implants include the wearing down of the plastic portion of the hip prosthetic, debris inside the replaced joint and loosening of the artificial hip joint due to bone loss (osteolysis). Improvements in the longevity of new types of polyethylene and metal-on-metal or ceramic bearings may help to reduce these effects.

Cementless devices are recommended for patients aged 50 years of age or less, or active patients whose bone growth into the hip prostheses may be predicted, as well as patients with juvenile inflammatory arthritis (JIA).