Joint replacement




Postoperative rehabilitation  

Hip and knee replacements are commonly performed surgical procedures. The main reason for a replacement is serious pain or limitation of function that cannot be managed otherwise. Joint replacements are major surgical procedures that require doing exercises and in-patient physiotherapy and out-patient rehabilitation following a stay in hospital. Osteoarthritis is the most common health problem requiring a joint replacement.

We present some of the evidence from Cochrane systematic reviews about complementary and alternative treatments related to joint replacement. This evidence comes from carefully researched reviews of information about clinical trials done to evaluate medical treatments. Studies are only included in these reviews if they meet pre-defined criteria.


Hip and knee replacement operations can be both stressful and painful. The main reason for a replacement is serious pain or limitation of function that cannot otherwise be successfully managed. 

What is known

Joint replacements are major surgical procedures. Feeling a lack of control over the situation is common after surgery and can increase the levels of anxiety and of pain. If a person is highly anxious, physical recovery and well-being may be affected and the length of stay in hospital increased. Having a better understanding of the operation, which can be very painful afterwards, and postoperative routines through preparatory information may help the patient to cope, remember information and improve physical recovery and psychological wellbeing.

Exercise is an important part of rehabilitation after the operation, in hospital and at home, and can reduce the likelihood of complications. During the initial hospital stay blood clots can form in the blood vessels of the leg if it is kept immobile. Another complication for people who have had a hip replacement is dislocation, usually if instructions on the positions to avoid are not followed.

Preparation for surgery and guidelines and programs for immediately after surgery are, therefore, considered important for recovery and some information is provided as part of standard care.

What the synthesised research says

Educating or informing patients preoperatively may not be sufficient to reduce postoperative anxiety or pain and improve functioning.

Educating and informing patients preoperatively without considering individual needs is not sufficient to improve functional recovery after a hip or knee replacement surgery and reduce the length of hospital stay.

Patients who are to have a hip or knee replacement receive some form of standardised information that consists mainly of printed materials as part of standard care.

How it was tested

The researchers made a thorough search of the medical literature and found nine controlled studies that randomly assigned a total of 782 participants to preoperative education programs or stand care. In seven of the studies, participants were having a hip replacement and in two studies both hip and knee replacements were included. On average people were aged between 58 and 71 years.

Four studies involving 365 patients could find no clear difference between those patients who had received preoperative education from usual care on the number of days it took after surgery to stand and climb stairs and the length of stay in hospital. On the other hand, one study of 133 people who had poor preoperative function and limited social support indicated that an individually tailored program that offered support helped in reducing the length of stay after a hip replacement.

Preoperative education did reduce the level of anxiety felt before the surgery in three studies (301 patients) by some 6 points on a scale 0 to 100 (range -7.5 to -3.8 points); but not after surgery either on the day following surgery, or at discharge.

Five studies reported on postoperative pain and did not detect any difference with and without preoperative education.

Preoperative education can be given before admission and can consist of just written information or also providing a video and plastic model bones to follow what is to be done.

Education on admission, but before surgery, can be provided using a video or teaching sessions delivered by physiotherapists or nurses.

One study combined preadmission written information with a teaching session on admission that was planned according to the needs of each participant. These people had poor function, limited social support and other existing illnesses.  

Side effects and general cautions

Reporting of postoperative complications was generally poor and cannot be commented on. This review did not include studies that provided education both before and after the joint replacement surgery. Instructions after surgery could remind the patient and reinforce what they have learned about what to do after surgery so that they do their exercises, mobilise and cope better.

The use of some form of preoperative education for all patients probably limits the benefits seen with preoperative education programs.

Preoperative information was only found to help the least anxious patients, in reducing pain medication - as part of the care process. Those people who are highly anxious or fearful may best be treated using psychological interventions.


S McDonald, S Hetrick, S Green. Pre-operative education for hip or knee replacement. Cochrane Database of Systematic Reviews 2004, Issue 1. Art. No.: CD003526.pub2. DOI: 10.1002/14651858.CD003526.pub2.


The ability to bend (flex) the knees help us to carry out a number of daily tasks. A minimum of 65 degrees is needed to walk normally, 90 degrees to go down stairs one leg after the other and at least 105 degrees is needed to get up from the toilet or a low chair. Not being able to tuck your legs up when sitting is also a problem, for example when travelling or in rowed seating.

Replacement of the knee joint with an artificial prosthesis (arthroplasty) involves major surgery. The purpose of the replacement is to improve pain and quality of life and is for people with severely damaged joints. The degenerative joint disease osteoarthritis and in a smaller number of instances rheumatoid arthritis are the major causes of  joint damage requiring replacement with artificial joints.

Movement of the joint soon after surgery helps with healing and is used to reduce joint stiffness. Stiffness is measured by the range of motion (ROM). Continuous passive motion is used by many surgeons as part of immediate postoperative management after a knee replacement (CPM). CPM involves a motorised machine placed on the bed that the leg fits into while the person lies in bed. The device repetitively moves the knee through a set circular movement of bending and straightening the leg. Because the machine does the work it is called passive movement; the arc of motion is increased over time so that the knee bends more and more. 

How CPM is used varies a lot in different hospitals in terms when it is started after surgery, the number of hours per day and the increments in the degrees of flexion each day. People also receive physiotherapy, which may consist of range of motion (ROM) exercises, muscle strengthening exercises, learning to walk or gait training, functional exercises and ice.

A complication of rehabilitation at home can be that the range of motion of the knee is limited. This may mean that a manipulation under general anaesthetic is needed.

What the synthesised research says

Continuous passive movement (CPM) immediately following a total knee replacement combined with physiotherapy has some benefit in rehabilitation over physiotherapy alone. 

Adding CPM to physiotherapy led to an overall small increase in active knee flexion. The length of stay in hospital was decreased and the chances of having to undergo a manipulation were reduced.

Size of effect  

CPM combined with physiotherapy increased active knee flexion by a mean of four degrees (range 2 to 7 degrees) and decreased length of stay by some 17 hours on average compared with physiotherapy alone. The relative risk for post-operative manipulation was an average of 0.12 (range 0.03 to 0.53). 

How it was tested

The researchers made a thorough search of the medical literature and found 14 controlled trials that randomised 952 adults undergoing total knee replacement to postoperative care with and without constant passive motion (CPM). Almost 90% of the participants had osteoarthritis and around 8% had rheumatoid arthritis. CPM treatment varied from 5 to 20 hours daily for from 18 hours to 2 weeks. CPM and physiotherapy generally began on the first post-operative day.

CPM combined with physiotherapy increased active knee flexion by two to seven degrees (4 studies, 286 patients) two weeks after surgery and decreased the length of hospital stay by some 17 hours (6 studies, 382 patients) compared with physiotherapy alone. The relative risk for post-operative manipulation ranged from 0.03 to 0.53 (3 trials) and depended on the base-line risk. 

Reductions in pain medication intake (3 studies, 157 patients) and knee swelling (2 studies) were reported lthough the number of trials and participants is low.

Low range CPM was no different from high range CPM in two studies measuring the amount of analgesic use, length of hospital stay or knee range of motion - at end of treatment or follow up at six weeks and one year.

Side effects and general cautions

CPM causes considerable inconvenience to the patient and staff and is expensive, so it is not accessible to everyone who has a knee replacement. How long a person stays in hospital is affected by many factors and policy can differ from hospital to hospital.

The mean methodological quality of the studies was low.

The clinical and practical significance of an extra four degrees of knee flexion is questionable, particularly if it does not result in additional ability to bend the knee one or two years post surgery and in the long term. No functional activities (sit to stand, lying down to sitting, moving around/ambulation, stair climbing, walking speed) were assessed using validated outcome measure scales.

How CPM is used in terms of the degree of bending, intensity and duration of use can vary considerable. Physiotherapy practices may also differ. Pre-operative exercises may also be used to reduce the decrease in muscle strength that occurs after knee replacement.

Trials were excluded if CPM was combined with other interventions such as: electrotherapy (ultrasound, interferential current, short wave diathermy, transcutaneous electrical nerve stimulation, neuromuscular electrical stimulation), hydrotherapy and heat.


S Milne, L Brosseau, V Robinson, MJ Noel, J Davis, H Drouin, G Wells, P Tugwell. Continuous passive motion following total knee arthroplasty. Cochrane Database of Systematic Reviews 2003, Issue 2. Art. No.: CD004260. DOI: 10.1002/14651858.CD004260.