Download January 2001 - Arthritis Research UK

COLLECTED REPORTS ON THE
Rheumatic Diseases
2005
SERIES 4 (REVISED)
Published by the
Arthritis Research Campaign (arc)
Editors:
Ade O Adebajo FRCP(Glasgow)
D John Dickson MBChB FRCP(Glasgow) FRCP(London) MRCGP
These reports are produced under the direction of the
arc Education Sub-Committee.
They were first published individually between 2000 and 2003
and were subsequently reviewed for this volume.
Osteoarthritis of
the Knee and Hip
Michael Doherty
Professor of Rheumatology and Consultant
Rheumatologist, Nottingham
THE PREVALENCE AND NATURE OF
OSTEOARTHRITIS
Peter Lanyon
Consultant Rheumatologist, Nottingham
Osteoarthritis (OA) is by far the most common joint disorder. It strongly associates with ageing and is a major
cause of pain and disability in the elderly. The knee
and hip are the principal large joints to be affected by
OA. Knee OA is more prevalent than hip OA, but taken
together they affect c.10–25% of those aged >65. Of all
medical conditions, knee OA is the single most important cause of disability in retirement years.
Gillian Hosie
Past President of Primary Care Rheumatology Society
and General Practitioner, Glasgow
•Osteoarthritis (OA) is by far the most
common joint disorder
OA is neither a disease nor a single condition. It is best
viewed as the dynamic repair process of synovial joints.
A variety of mechanical, metabolic or constitutional insults may trigger OA (Figure 1). Often the insults remain
unclear (primary OA) but sometimes a clear cause such
as trauma may be apparent (secondary OA). All the joint
tissues (cartilage, bone, synovium, capsule, ligament,
muscle) depend on each other for health and function.
Insult to one impacts on the others, resulting in a common OA phenotype affecting the whole joint. The OA
process involves loss of tissue but also new tissue production, most notably bone (osteophyte), and remodelling of joint shape. Often OA compensates for the insults, resulting in an anatomically altered but pain-free
functioning joint (compensated OA). Sometimes, however, it fails, resulting in progressive joint damage, associated symptoms and presentation as an OA patient with
joint failure. Such a perspective explains the clinical
heterogeneity of OA and the variable clinical outcomes
observed.
•Up to a quarter of people over 65 have
knee or hip OA
•Risk factors include positive family
history, obesity, injury, and repetitive
heavy joint loading
•Appropriate simple management can
greatly benefit the OA patient
•Education and both aerobic and
strengthening exercise are essential
interventions for every OA patient
RISK FACTORS FOR KNEE AND HIP
(LARGE JOINT) OSTEOARTHRITIS
Both constitutional and local biomechanical factors
predispose to development of knee and hip OA (large
joint OA – LJOA) (Table 1). Their relative importance differs at the two sites and between individuals. Inheritance
is a major attributable factor for LJOA. For example:
• Siblings of someone who undergoes surgery for hip
OA have a 5-fold higher than expected (relative) risk
of having radiographic hip OA themselves.
First published January 2001; reviewed August 2005
89
tors and obesity correlate more strongly with pain and
disability than x-ray change. Such factors are potentially modifiable, giving optimism with respect to
treatment.
INSULTS
OUTCOME
traumatic
biomechanical
‘compensation’
inflammatory constitutional
no/mild
symptoms or disability
unidentified
DIAGNOSIS AND ASSESSMENT
OA PROCESS
cartilage
capsule
bone
synovium
This is purely clinical. Only an adequate enquiry and
examination can determine pain causation and severity,
degree of disability and the impact of LJOA on the
patient’s life. Enquiry concerning family history, occupation and prior injury, and examination for Heberden’s
nodes and obesity may give clues as to causation (Figure 2).
‘decompensation’
symptoms, disability
potential for progressive damage
REPAIR
FIGURE 1. Osteoarthritis as a repair process.
OA pain typically has the following characteristics:
• Siblings of someone who undergoes surgery for knee
OA have a 3-fold relative risk of severe knee OA.
• Development of Heberden’s nodes in middle age is a
marker for strong genetic predisposition to develop
knee OA as part of nodal generalised OA.
• insidious onset, variable or intermittent over time
(‘good days, bad days’)
• mainly related to movement and weight-bearing, relieved by rest
• only brief (usually <15 minutes) morning stiffness
or ‘gelling’ after rest
• usually only one or a few joints (not multiple regional
pain)
• knee pain – well localised to the anterior or medial
aspect of the knee and upper tibia. Patellofemoral pain
is worse going up and down stairs or hills. Posterior
pain suggests a complicating popliteal cyst.
• hip pain – usually maximal in the anterior groin, with
variable radiation to the buttock, anterolateral thigh,
knee or shin. Referred pain may present at the knee,
but unlike knee OA pain it is diffuse, often relieved
by rubbing, and on examination hip (not knee) movement reproduces it. Lateral pain – worse on lying on
The responsible genes for common LJOA have yet to be
identified. Obesity, trauma and repetitive adverse loading
of the knee (during occupation or highly competitive
sports) are potentially avoidable factors. LJOA under age
45 is rare in the absence of overt trauma or prior joint
disease and requires consideration of rare causes (e.g.
dysplasia or haemochromatosis).
Correlation between presence of structural OA (clinical
signs, x-ray changes) and pain and disability varies according to site. It is much stronger at the hip than the
knee. Risk factors for pain and disability may differ from
those for structural change. At the knee, for example,
reduced muscle strength, adverse psychosocial fac-
TABLE 1. Important risk factors for the development of knee and hip OA.
Constitutional risk factors
Knee OA
Hip OA
Racial predisposition
Unidentified genetic factors
Heberden’s nodes
Gender
Ageing
Obesity
All races
+++
+++
Female predominant
+++
+++
White individuals
+++
–
Women = men
++
+
Local risk factors
Knee OA
Hip OA
Trauma
• internal derangement
• instability
+++
++
++
+
Occupation, recreation
Repetitive knee bending while
carrying heavy loads
Mining
Professional footballers
Farming
Elite athletes (men, women)
Congenital/childhood joint disease
–
Perthes’
Slipped femoral epiphysis
Congenital dislocation
Dysplasia
90
RISK FACTORS
INVESTIGATION
KNEE SIGNS
An x-ray is the only useful investigation, though not a
required one (knees – standing anteroposterior (AP)
with flexed skyline or lateral views; hips – posteroanterior (PA) pelvis). This may show one or more of the
typical features of OA, namely focal narrowing, osteophyte, sclerosis, cysts, deformity. Its main use is in assessing severity of structural change, an issue when surgery
is being considered. OA has no impact on any routine
blood test (e.g. blood count, erythrocyte sedimentation
rate (ESR)).
crepitus
restricted
flexion/extension
elderly
woman
bony swelling
medial tibiofemoral
tenderness
positive
family
history
obesity
Heberden’s nodes
MANAGEMENT
FIGURE 2. Examination of an elderly woman with
The objectives of management are to:
• inform the patient concerning the nature and management of OA
• control pain
• optimise function
• beneficially modify the OA process.
knee pain.
that side – with tenderness over the greater trochanter
suggests secondary trochanteric bursitis.
Common functional difficulties are bending to put
on socks and shoes, rising from a chair, getting in or
out of a car, and prolonged walking. Pain and restricted
movement may separately contribute to these difficulties. Patients with chronic pain may additionally have
non-restorative sleep, night pain, fatigue and low mood
which compound their pain and disability.
Successful management requires assessment of the person, not just the painful joint. The management plan
must be individualised, taking into account factors
such as:
• patient attitudes and knowledge
• self-treatments
• constitutional factors (e.g. obesity, muscle weakness,
non-restorative sleep)
• co-morbid disease and its therapy
• treatment availability, practicality, safety and costs.
The following local examination findings may be
present:
• a jerky, asymmetric, antalgic gait (less time weightbearing on painful side)
• weakness and wasting of quadriceps (knee/hip OA)
and gluteal (hip OA) muscles
• knee examination may reveal:
- restricted flexion, extension
- coarse crepitus
- joint-line and/or periarticular tenderness (second ary anserine bursitis and medial ligament enthes opathy are common, giving tenderness of upper
medial tibia)
- deformity – varus (less commonly valgus) and/or
fixed flexion
- bony swelling around joint margins (osteophyte)
- only a mild to modest effusion, if at all; posterior
fluid swelling (popliteal cyst)
• hip examination may reveal:
- restriction of internal rotation with the hip flexed
- the earliest and most sensitive sign of hip OA (Fig ure 3); other movements may subsequently be re stricted and painful
- anterior groin tenderness just lateral to femoral
pulse
- deformity – fixed flexion and/or external rotation
of the hip; leg shortening.
The summary that follows accords with recent evidencebased guidelines for OA management. There are essential
interventions to be considered in every LJOA patient and
additional options from which to select for individual
patients and circumstances.
FIGURE 3. Internal rotation of the hip (pulling the
foot outwards) with the hip flexed at 90º – the most
sensitive test for hip OA.
91
‘Essentials’ – for every patient
(a)
Education and information access
It is every practitioner’s responsibility to educate their
patient (together with caregivers, as appropriate) concerning the nature of their condition and its investigation, treatment and prognosis. In addition to professional responsibility, however, education in itself benefits outcome. Although the mechanisms are unclear,
information access and therapist contact both reduce
pain and disability, improve self-efficacy (autonomy),
and reduce health care costs. Such benefits are modest
but long-lasting and safe. Education techniques effective for LJOA include group classes; individualised packages; monthly telephone reviews; learning coping skills;
literature; and interactive computer programmes. Reenforcement of identical, not conflicting, information
requires team management by doctors, physiotherapists
and practice nurses.
Quadriceps
muscle
(b)
A prescription of exercise
Aerobic fitness training (causing the patient to sweat,
get breathless and increase their heart rate) has longterm efficacy in reducing OA pain and disability. The
mechanism is unclear, though an increased sense of
well-being, weight loss, and improved sleep are recognised benefits. Such exercise also benefits common comorbidity such as obesity, diabetes, chronic heart failure and hypertension. Local strengthening exercise
for quadriceps (Figure 4) and gluteals also reduces pain
and disability from LJOA with accompanying improvements in muscle strength, proprioception and standing
balance, all of which are impaired in LJOA. No age is
exempt from undertaking or benefiting from these two
forms of exercise. Both are usually combined in a graded
programme, with incremental increases tailored to the
individual. ‘Small amounts often, for life’ is advised.
Although often given as therapist-supervised classes,
simple unsupervised graded home exercise programmes
(using elastic resistance bands for the strengthening component) are readily taught and also effective.
FIGURE 4. Simple quadriceps-strengthening
exercises.
(a) Straight-leg raise: sitting. The patient should sit
well back in a chair with a good posture. Then straighten
and raise the leg, hold it for a slow count to 10, and
slowly lower it. This should be repeated at least 10
times with each leg. If this can be done easily, repeat
the exercises with a weight hanging on the ankle.
(b) Straight-leg raise: lying. The patient can get into the
habit of doing straight-leg exercises in the morning and
at night while lying in bed. With one leg bent at the
knee, the other leg should be held straight and lifted so
that the foot is just off the bed. This should be held for
a slow count of 5, then lowered. Repeat with each leg 5
times every morning and evening.
Advice on weight loss if obese
Obesity aggravates pain and disability in LJOA and is an
important risk factor for structural progression and a
poor outcome. Patients who are overweight should be
given the rationale for weight loss. Current eating habits
should be discussed and specific advice given on how to
achieve slow but steady weight loss through alteration
of dietary and eating habits for life. Concurrent aerobic
exercise and regular monitoring improve success.
Reduction of adverse mechanical factors
Physically demanding activities (e.g. shopping, gardening,
long walks) should be interrupted by frequent breaks.
Such ‘pacing’ extends the time needed to undertake
important tasks, but allows their completion, reduces
mechanical insult, and maintains morale. Appropriate
footwear can also reduce LJOA symptoms. The ideal
shoe has four qualities: a thick but soft sole (to reduce
rebound impact loading), no raised heel, a broad forefoot, and soft, deep uppers. Air-filled trainers are ideal,
but fashionable shoes with these features are also widely
available.
Simple analgesia
Paracetamol (1 g up to 3–4 times daily) is the agreed oral
drug of first choice and, if successful, is the preferred
long-term oral analgesic. This is because of its efficacy,
lack of contraindications or drug interactions (except for
high dose warfarin), and long-term safety. Some patients
are concerned about toxicity and need reassurance.
The drug has a narrow therapeutic/toxicity ratio but as
long as the daily dose is not exceeded it is safe. Many
people, of course, self-medicate with paracetamol. For
92
Intra-articular injections (knee OA)
Intra-articular injection of long-acting steroid (e.g. triamcinolone hexacetonide 20 mg; triamcinolone acetonide 40 mg; methylprednisolone acetate 40 mg) can give
rapid, effective, but temporary relief of pain (acts within
24 hours, lasts 2–6 weeks). This can be useful for quick
control of severe pain, to tide someone over a special
event (e.g. family wedding, holiday), or to temporarily
control pain while longer-term interventions such as
exercise are instituted. There are no clear predictors of
response (age, x-ray severity, presence of effusion) so it
may be considered in anyone with moderate–marked
pain. Injections are not usually repeated more than
3–4 times per year because of theoretical concerns of
steroid-induced joint tissue atrophy. Several preparations of hyaluronan (e.g. sodium hyaluronate) and
its derivatives hylans (e.g. hylan G-F 20) are available,
all highly viscous but differing in molecular weight and
degree of polymerisation. Initially given for their lubricant properties (viscosupplementation), these compounds have numerous other biological actions which
may relate to symptom modification. They are given
mainly as a course of 3 (hylan) or 5 (hyaluronan) weekly
injections; only one recently introduced product is recommended as a single injection. Modest symptom improvement (above placebo) can occur within a few weeks
and last for several months. Major drawbacks, however,
are the frequency of injection and their expense.
many OA patients it is as effective as oral non-steroidal
anti-inflammatory drugs (NSAIDs). It lasts for 4–6 hours
and is taken as required, but preferably before rather than
after an activity (e.g. shopping) that regularly exacerbates
pain. If it provides some, but insufficient, relief it should
be continued and another option added.
Additional options
Topical creams/gels (knee OA)
Topical NSAIDs are popular with patients, extremely
safe (with epidemiological evidence for no risk of gut
bleeding/perforation) and relatively effective for pain
relief in knee OA. Efficacy data vary between individual
products and they need to be judged independently rather
than on a class basis. They have received a bad press,
mainly because of expense, but several are available over
the counter (OTC). Topical capsaicin (0.025%), from
pepper plants, has specific effects on nociceptive C fibres
and, if used regularly, several times daily, is relatively effective and very safe. Initial burning sensations may be
distressing but diminish after the first few applications
(which should be given sparingly). Both topical agents
can be used as single therapy, or as adjuncts to oral
analgesics.
Other oral analgesics (knee/hip OA)
Opioid analgesics (codeine, dihydrocodeine) may be
stronger for some patients than paracetamol alone, but
any benefit is often offset by frequent adverse effects
such as constipation, headache and confusion. They are
mainly used as an adjunct to paracetamol (prescribed
separately or as a combined preparation). Oral NSAIDs
are no more effective for most OA patients than paracetamol, though some patients clearly do obtain more
symptom relief from an NSAID. Data on long-term efficacy are sparse and most patients discontinue NSAIDs
within 1 year. Gastrointestinal (GI) bleeding and perforation are the most serious life-threatening side-effects
but lesser GI symptoms, fluid retention and drug interactions are not uncommon. Unfortunately most OA
patients are at the highest risk from NSAID toxicity (elderly, co-morbid conditions, other drugs) so NSAIDs are
best avoided if possible, especially in elderly or infirm
patients. If given to high-risk patients, co-prescription
with a proton-pump inhibitor or misoprostol should be
considered. Highly selective COX-2 inhibitors are no
stronger analgesics than traditional NSAIDs. Although
some show no evidence of increased risk of GI ulceration
they still have other side-effects on the cardio-renal system
and may increase the risk of myocardial infarction, heart
failure and stroke, especially in those with existing cardiac risk factors. Following recent withdrawal of some of
these agents the safety of both highly selective COX-2
inhibitors and traditional NSAIDs is currently under
evaluation.
Other physical approaches (knee/hip OA)
Local heat (bath, hot water bottle, OTC rubs) and cold
(wrapped ice pack) may relieve pain and stiffness. Such
relief is temporary and, except for bathing, mainly suited
to knee OA. For more disabled patients, modification
of the patient’s environment (raised chairs and toilet
seat, an ‘extended hand’ for socks and tights, other
aids) should be considered. A walking stick can be
reassuring and can reduce load across an OA joint if
held in the contralateral hand and of sufficient length to
reach the pelvic brim. Assessment by a physiotherapist
or occupational therapist can maximise the benefits of
such physical approaches.
Food products (‘nutriceuticals’)
Several natural products, such as chondroitin and glucosamine, are available unlicensed OTC. Their rationale
for OA is that as basic ingredients of some cartilage
components they assist production of cartilage matrix.
There is some evidence for a modest, slow-onset analgesic action in LJOA (taking 2–4 weeks) and studies of
glucosamine report possible slowing of structural progression in knee OA over a 3-year period (chondroprotection). However, there are reservations over these
studies and the results of a large independent National
Institutes of Health (NIH) study of both glucosamine
93
and chondroitin are awaited. Such products appear safe
and are very popular with patients. Caveats to their use
include the bovine origin of chondroitin and absence, as
a food product, of the rigorous quality control required
for drugs.
Additional measures for severe pain may include stronger
opioid analgesics (e.g. nefopam, tramadol, meptazinol),
transcutaneous electrical nerve stimulation (TENS) machines, local nerve blocks, or knee lavage, though such
measures are usually for temporary control while awaiting
more definitive surgery.
WHO MAY NEED SURGERY?
OPPORTUNITIES FOR PRIMARY AND
SECONDARY PREVENTION
Total joint replacement can be very successful in eliminating or reducing pain and improving the quality of
life of patients with severe hip or tibiofemoral (not isolated patellofemoral) knee OA. There are no universally
agreed criteria for surgery and the pros and cons need
balancing for each patient. In general, however, the indications are:
Avoidance and reduction of obesity, undue trauma during sports, and repetitive knee bending while carrying
heavy loads at work are obvious strategies for primary
prevention. Individuals at particular risk of LJOA include:
• those with a clear family history of knee or hip OA
• those with multiple Heberden’s nodes (increased risk
of knee OA)
• patients with unilateral LJOA unrelated to obvious
trauma (greatly increased risk of developing contralateral OA).
• chronic pain and/or functional disability that importantly disrupts the patient’s life
• failure of adequate conservative therapies
• definite radiographic OA (moderate-severe structural
change is required by many).
Although success rates are excellent or good for the
vast majority of patients, there is an associated mortality
(c.1%). Fitness for major surgery requires assessment.
Breathlessness is a symptom for concern but many comorbid conditions, including obesity, are not absolute
contraindications. Local anaesthesia can be considered
for compromised patients. Surgery is often most successful in the elderly in terms of prosthesis survival
times; younger patients (<65) place more demands on
their joints and have earlier loosening and prosthesis
failure. Nevertheless, the outcome of the patient is more
important than prosthesis survival and concerns over
the need for revision, with its lower success rate, need
weighing against the patient’s current needs and attitudes. The rate of total knee replacement in the UK is
lower than in many other European countries and we
may be unduly delaying surgery for some patients.
Such people should be informed of their increased risk
and given advice concerning weight control, regular
aerobic and strengthening exercise for both legs (irrespective of symptoms), and appropriate shock-absorbing
footwear. Through such lifestyle modification it is within
their control to reduce their risk for subsequent LJOA.
FURTHER READING
Pendleton A, Arden N, Dougados M, Doherty M, Bannwarth B, Bijlsma
JW et al. EULAR recommendations for the management of knee osteoarthritis. Report of a task force of the Standing Committee for
International Clinical Studies Including Therapeutic Trials (ESCISIT).
Ann Rheum Dis 2000;59(12):936-44.
Jordan KM, Arden NK, Doherty M, Bannwarth B, Bijlsma JW, Dieppe
P et al. EULAR recommendations 2003: an evidence-based approach
to the management of knee osteoarthritis. Report of a task force of
the Standing Committee for International Clinical Studies Including
Therapeutic Trials (ESCISIT). Ann Rheum Dis 2003;62(12):1145-55.
Zhang W, Doherty M, Arden N et al. EULAR evidence based recommendations for the management of hip osteoarthritis: report of a task
force of the EULAR Standing Committee for International Clinical
Studies Including Therapeutics (ESCISIT). Ann Rheum Dis 2005;64(5):
669-81.
WHEN TO REFER LARGE JOINT
OSTEOARTHRITIS
American College of Rheumatology Subcommittee on Osteoarthritis
Guidelines. Recommendations for the medical management of osteoarthritis of the hip and knee: 2000 update. Arthritis Rheum 2000;43(9):
1905-15.
Secondary referral may be required for access to appropriate physiotherapy or occupational therapy. In addition,
the following may prompt specialist referral:
Hosie G, Dickson J. Managing osteoarthritis in primary care. Oxford:
Blackwell Science; 2000.
• diagnostic uncertainty
• persistent poorly controlled pain
• progressive pain or disability despite adequate conservative measures (surgery?)
• sudden worsening or change in character of pain
(secondary osteonecrosis?)
• history of knee ‘locking’ suggesting concurrent internal
derangement
• patient request for further advice or reassurance.
Dickson DJ, Hosie G. Osteoarthritis: your questions answered.
Edinburgh: Churchill Livingstone; 2003.
Doherty M, Dougados M (ed). Osteoarthritis: current treatment strategies. Best Pract Res Clin Rheum 2001;15(4).
Underwood M. Chronic knee pain in the elderly. Reports on the Rheumatic Diseases (Series 5), Hands On 5. Arthritis Research Campaign;
2005 Feb.
Hurley M. An exercise in knee pain self-management. Reports on
the Rheumatic Diseases (Series 5), Hands On 6. Arthritis Research
Campaign; 2005 Jun.
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