Rheumatology Flashcards
Causes of low back pain
- Mechanical (soft-tissue lesion) back pain
- Intervertebral disc lesions (e.g. prolapse, disc degeneration)
- Facet joint disease (osteoarthritis, psoriatic arthritis)
- Vertebral fracture
- Paget’s disease
- Axial spondyloarthritis
- Spondylodiscitis
- Spondylolisthesis
- Bone metastases
- Scheuermann’s disease
Features of mechanical low back pain
-
Time:
- Often sudden
- Recurrent episodes
-
Factors:
- Precipitated by lifting or bending
- Pain varies with physical activity (improved with rest)
- Site: Limited to back or upper leg
- No clear-cut nerve root distribution
- No systemic features
- Prognosis good (90% recovery at 6 weeks)
Back pain >>> Red flags for possible spinal pathology
History:
- Age: presentation < 20 years or > 55 years
- Character: constant, progressive pain unrelieved by rest
- Location: thoracic pain
- Past medical history:
- Carcinoma
- Tuberculosis
- HIV
- Systemic glucocorticoid use
- Osteoporosis
- Constitutional: systemic upset, sweats, weight loss (B symptoms like)
- Major trauma
Examination:
- Painful spinal deformity
- Severe/symmetrical spinal deformity
- Saddle anaesthesia
- Progressive neurological signs/muscle-wasting (neurological)
- Multiple levels of root signs (neurological)
Clinical features of radicular pain
Clinical features of radicular pain
- Nerve root pain
- Unilateral leg pain worse than low back pain
- Pain radiates beyond knee
- Paraesthesia in same distribution
- Nerve irritation signs (reduced straight leg raising that reproduces leg pain)
- Motor, sensory or reflex signs (limited to one or adjacent nerve roots)
- Prognosis reasonable (50% recovery at 6 weeks)
Cauda equina syndrome
- Difficulty with micturition
- Loss of anal sphincter tone =/ faecal incontinence
- Saddle anaesthesia
- Gait disturbance
- Pain, numbness or weakness affecting one or both legs
Clinical assessment of back pain
The main purpose: To differentiate the self-limiting disorder of acute mechanical back pain from serious spinal pathology
Mechanical back pain >>> frequency
- It is the most common cause of Acute back pain in aged 20–55 >>> accounts for more than 90% of episodes
- Low back pain is more common in → manual workers
- Particularly those involve heavy lifting and twisting.
How to assess mechanical back pain
-
Presentation:
- It is usually Acute
- Associated with >>> lifting or bending.
- Exacerbated by >> activity
- Relieved by >>> rests
- confined to the lumbar–sacral region, buttock or thigh
- Asymmetrical
- Does not radiate beyond the knee (which would imply nerve root irritation)
-
O/E:
- Asymmetrical
- Local paraspinal muscle spasm
- Tenderness
- Painful restriction of some, but not all, movements.
Mechanical back pain >>> prognosis
- Generally good
- After 2 days >>> 30% are better
- By 6 weeks >>> 90% have recovered
- Recurrences of pain may occur
- About 10–15% of patients >>> go on to develop chronic back pain >>> that may be difficult to treat.
Factors that may cause transition of acute mechanical back pain to a chronic pain
Psychological elements, such as
- job dissatisfaction
- Depression
- Anxiety
Back pain secondary to serious spinal pathology (Not mechanical) ⇒
Urgent investigation is needed if there is - ?
- clinical evidence of spinal cord or nerve root compression
- sepsis including tuberculosis, or
- a cauda equina lesion
Spinal stenosis >>> presentation
- Presents insidiously
- Leg discomfort on walking
- Relieved by >>>
- Rest
- Bending forwards (Thus may be more area is formed within)
- Walking uphill
- May adopt characteristic simian posture, with >>>
- Forward stoop + slight flexion at hips and knees.
Spinal stenosis >>> the most common cause
The most common cause is:
Gadual development of coexisting contributing lesions such as >>>
- Facet joint arthritis
- Ligament flavum thickening or
- Degenerative spondylolisthesis.
Degenerative disc disease is more common in -?
It is a common cause of chronic low back pain in middle-aged adults.
Prolapsed intervertebral disc >>> presentation
Prolapse of an intervertebral disc presents when >>> discs are still well hydrated
- Young and early middle age >>> nerve root pain
- Can be accompanied by >>>
- A sensory deficit
- Motor weakness
- Asymmetrical reflexes
- Examination may reveal > positive sciatic or femoral stretch test.
Prolapsed intervertebral disc >>> prognosis
About 70% of patients improve by 4 weeks.
Inflammatory back pain (IBP) >>> 2 important causes
- Axial spondyloarthritis (axSpA)
- Psoriatic arthrits (PsA)
Inflammatory back pain >>> presentations
[due to axial spondyloarthritis (axSpA) &
Psoriatic arthrits (PsA)]
- Gradual onset
- Almost always before the age of 40
- Associated with morning stiffness
- Improves with movement
Spondylolisthesis >>> presentation
- Back pain
- Typically aggravated by standing and walking
Occasionally, diffuse idiopathic skeletal hyperostosis >>>>> can cause back pain but it is usually asymptomatic.
Arachnoiditis
Rare cause of chronic severe low back pain
Arachnoiditis >>> cause
- Chronic inflammation of the nerve root sheaths in the spinal canal >>> further, can complicate meningitis
- Spinal surgery or
- Myelography with oil-based contrast agents.
When is investigation needed in back pain?
- Acute mechanical back pain > No investigation required
- Persistent pain (> 6 weeks) OR red flags >>> need further investigation
Back pain >>> Investigation of choice (IOC)
MRI (Magnetic resonance imaging)
In back pain, MRI is the IOC >>> because?
Because, it can demonstrate >>>
- spinal stenosis
- cord compression
- nerve root compression
- inflammatory changes in axSpA
- sepsis
- malignancy
Investigations of back pain >>> imgaing modalities
- MRI (MAgnetic resonance imaging) >>> IOC
- Plain X-ray
- Bone scintigraphy
Indications of ‘plain X-ray’ in back pain
- Suspected vertebral compression fractures
- OA (Osteroarthritis)
- Degenerative disc disease
Indication of bone scintigraphy in back pain
If metastatic disease is suspected
Back pain >>> additional investigations
- Routine biochemistry
- CBC (= haematology)
- ESR
- CRP (to screen for sepsis and inflammatory disease)
- Protein and urinary electrophoresis >>> for myeloma
- HLA-B27 status >>> in IBP
- PSA >>> for prostate carcinoma
Pateint with low back pain >>> indications of surgery
- Progressive spinal stenosis
- Spinal cord compression with nerve root compression
Management of back pain
- Education is important in mechanical back pain. Eemphasise >>>
- It is self-limiting condition
- Exercise is helpful (rather than damaging)
- Regular Analgesia and/or NSAIDs (may be required) >>> to improve mobility + to facilitate exercise.
-
Return to work and normal activity (ASAP)
- Bed rest is NOT helpful >>> may increase the risk of chronic disability.
- If a return to normal activities has not been achieved by 6 weeks >>> refer for physical therapy
- Low-dose tricyclic antidepressant >>> may help pain, sleep and mood.
Other occasional treatment modalities >>>
- Epidural and facet joint injection
- Traction
- Lumbar supports
(though there is limited RCT evidence to support their use)
- Malignant disease, osteoporosis, Paget’s disease and SpAs >>>>> specific treatment of the underlying condition.
- Surgery is required in less than 1% of patients with low back pain
Osteoarthritis: epidemiology
- The prevalence rises progressively with age
- At some point of life >>> 45% of all people develop knee OA and 25% hip OA
- Although some are asymptomatic >>>>> the lifetime risk of having a total hip or knee replacement for OA in someone aged 50 is about 11% for women and 8% for men in the UK.
- There are major ethnic differences in susceptibility:
- The prevalence of hip OA is lower in Africa, China, Japan and the Indian subcontinent than in European countries, and that
of knee OA is higher.- Higher prevalence of knee OA in the Indian subcontinent and East Asia might be accounted for by squatting.
Osteoarthritis: Risk factors
Genetics
• Skeletal dysplasias
• Polygenic inheritance (in most cases > polygenic; several genetic variants of small effects)
- Heritability of OA ranges from >>>
- Knee > 43%
- Hip > 60%
- Hand > 65%
- OA can, however, be a component of multiple epiphyseal dysplasias >>>>> caused by mutations in the genes that encode components of cartilage matrix.
Developmental abnormalities (/structural abnormalities)
Cause:presumably due to >>> abnormal load distribution across the joint
• Developmental dysplasia of the hip
• Slipped femoral epiphysis
>>> these are associated with a high risk of OA
(Similar mechanisms probably explain the increased risk of OA in patients with limb deformity secondary to Paget’s disease of bone)
Repetitive loading (due to ‘biomechanical factors’)
• Farmers >>> hip OA
• Miners >>> knee OA
• Elite or pofessional athelets >>> knee or ankle OA
Adverse biomechanics (who have had destabilising injuries)
• Meniscectomy
• Ligament rupture
• Paget’s disease
Obesity (strong association)
- Particularly hip >>> thought to be,partly due to >>>
- biomechanical factors
- (also play a role) cytokines released from adipose tissue
Trauma
Hormonal(Oestrogen appears to play a role)
• Oestrogen deficiency
• Aromatase inhibitors (for therapy of breast cancer) >>> flare of OA symptoms
Neutral factor: Participation in recreational sport >>> does not increase risk significantly
Protective factor: HRT; >>> women who use HRT have lower rates of OA
Osteoarthritis: main pathological process
- Defining feature of OA: degenation of articular cartilage
- Normally, chondrocytes are terminally differentiated cells
- In OA >>> chondrocytes start dividing to produce >>> “nests of metabolically active cells”
- Initially, matrix components are produced by these cells (at an increased rate)
-
At the same time >>> accelerated degradation of the major
structural components of cartilage matrix, including aggrecan
and type II collagen -
Eventually, the concentration of aggrecan in cartilage matrix falls >>> makes the cartilage vulnerable to load-bearing injury >>> fissuring of the cartilage surface (‘fibrillation’) then occurs >>> leading to >>
- the development of deep vertical clefts
- localised chondrocyte death
- decreased cartilage thickness.
>>>This is initially focal >>> mainly targeting the maximum load-bearing part of the joint >>> But eventually > large parts of the cartilage surface are damaged >>> in the abnormal cartilage, c__alcium pyrophosphate and basic calcium phosphate crystals often become deposited
Osteoarthritis: defining feature
degenation of articular cartilage
Osteoarthritis: pathology in sub-chondral bone
Abnormalities in subchondral bone >>>
- sclerotic
- the site of subchondral cysts
Osteoarthritis >>> joint margin
At the joint margin >>> fibrocartilage is produced >>> undergoes endochondral ossification >> form osteophytes
Osteoarthritis >>> shape
- Bone remodelling + cartilage thinning >>> slowly alter the shape of the OA joint >>> increasing its surface area.
- Homeostatic mechanism operative in OA >>> causes > enlargement of the failing joint >>> to spread the mechanical load over a greater surface area.
Osteoarthritis >>> BMD and osteoporosis
- Higher BMD values (at sites distant from the joint) + particularly, associated with osteophyte formation.
- Patients with OA are partially protected from developing osteoporosis and vice versa.
- Why: the genetic factors that predispose to osteoporosis might be protective for OA.
Osteoarthritis >>> the synovium
- in OA >>> the synovium is often hyperplastic
- It may be the site of inflammatory change
- But to a much lesser extent than in RA &other inflammatory arthropathies.
-
Osteochondral bodies commonly occur within the synovium, reflecting >>>
- chondroid metaplasia or
- secondary uptake and growth of damaged cartilage fragments
Osteoarthritis >>> the outer capsule
Outer capsule also thickens and contracts >>> usually retaining the stability of the remodelling joint.
Osteoarthritis >>> surrounding muscles
Around the joints >>> wasting of muscles + non-specific type II fibre atrophy
Osteoarthritis >>> Clinical features (signs & symptoms)
- *Main presenting symptoms:** joint pain + functional restriction
- *Characteristic distribution:** the hips, knees, PIP and DIP joints of the hands, neck and lumbar spine
Pain
- Onset: insidious >>> over months or years
- Nature: Variable or intermittent nature over time (‘good days, bad days’)
- Mainly related to/increased by >>> movement and weight-bearing
- Releived by >>> Rest
- Only brief (<15 mins) morning stiffness and brief (<5 mins) ‘gelling’ after rest
- Usually only one or a few joints painful
Clinical signs
-
Restricted movement
- For many people, functional restriction of the hands, knees or hips is an equal, if not greater, problem than pain
- Coarse crepitus: Palpable, sometimes audible
- Bony swelling (Around joint margins)
- Tenderness (Joint-line or periarticular)
- Deformity (usually without instability)
- Muscle weakness and wasting
- Mild or absent synovitis
- The clinical findings vary according to severity but are principally those of joint damage.
Osteoarthritis >>> cause of joint pain
The causes of pain in OA are not completely understood but may relate to >>>
- increased pressure in subchondral bone (mainly causing night pain)
- Trabecular microfractures
- Capsular distension
- Synovium >>> Low-grade synovitis
- Bursitis (may also be)
- Enthesopathy (Secondary to altered joint mechanics) (may also be)
Coarse crepitus in OA (palpable +/- audible) >>> cause?
Rough articular surfaces
Restricted movement in OA >>> cause?
due to capsular thickening or blocking by osteophyte
Osteoarthritis >>> the correlation between structural changes (assessed by imaging) & clinical features
The correlation between the presence of structural change (as assessed by imaging, and symptoms such as pain and disability)
Varies markedly according to site. The correlation >>>
- Stronger at the hip (than that of knee)
-
Poor at small joints
This suggests that >>>
the risk factors for pain and disability may differ from those for
structural change. >>>> for example >>>- At the knee, >>>>> reduced quadriceps muscle strength + adverse psychosocial factors (anxiety, depression) >>>> correlate more strongly with pain and disability [[than the degree of radiographic change]]
- Radiological evidence of OA is very common in middle-aged and older people
- The disease may coexist with other conditions, >>> so it is important to remember that >>> pain in a patient with OA may be due to another cause.
Generalised nodal OA: characteristics
- Age: Peak onset in the middle age
- Sex: Marked female preponderance
-
Genetics: Strong genetic predisposition;
- the daughter of an affected mother has a 1 in 3 chance of
developing nodal OA herself.
- the daughter of an affected mother has a 1 in 3 chance of
-
In hand:
- Polyarticular >>> finger interphalangeal joint OA
- Heberden’s (± Bouchard’s) nodes
- Good functional outcome for hands
- Predisposition to OA at other joints, especially knees
Generalised nodal OA >>> course of the disease
Some patients are asymptomatic …..
whereas, others >>> From 40 years onwards >>> at one or more PIP and DIP joints of the hands >>> pain + stiffness + swelling >>> gradually, these develop posterolateral swellings on each side of the extensor tendon >>> which slowly enlarge + harden >> become Heberden’s (DIP) and Bouchard’s (PIP) nodes.
Typically, Each joint >>> goes through a phase of episodic symptoms (1–5 years)
>>> while the node evolves and OA develops >>>
Once OA is fully established >>>
- Symptoms may subside + hand function often remains good
- Due to osteophyte formation >>> affected joints are enlarged
- characteristic lateral deviation (often showed) >>> reflecting the asymmetric focal cartilage loss of OA
If generalised nodal OA involves first CMC (Carpo-metacarpal) joint >>> Sign and symptoms
Involvement of the first CMC joint is also common, leading to >>>
- Pain on trying to open bottles and jars
- Functional impairment
Clinically, it may be detected by >>>- The presence of crepitus on joint movement, and
- Squaring of the thumb base
Targeted area in Knee OA
At the knee, OA principally targets >>>
- the patello-femoral compartment
- the medial tibio-femoral compartments
But eventually spreads >>> to affect the whole of the joint
It may be >>>
- Part of generalised nodal OA or isolated OA
- Most patients have bilateral and symmetrical involvement.
Knee OA >>> important risk factor in men
Trauma
>>> may cause unilateral OA
Knee OA >>> symptoms
- Localised pain >>> in the anterior or medial aspect of the knee and upper tibia.
- Patello-femoral pain >>> (usually) worse going up and down stairs or inclines.
- If posterior knee pain >>> suggests >>> the presence of a complicating popliteal cyst (Baker’s cyst).
- Difficulties in tasks, such as:
- Prolonged walking
- Rising from a chair
- Getting in or out of a car
- Bending to put on shoes and socks
Knee OA >>> signs (local examination findings)
- Gait: A jerky, asymmetric (antalgic) gait + less time weightbearing on the painful side
-
Deformity:
- Varus
- Valgus (less commonly)
- (and/or) fixed flexion deformity
-
Tenderness:
- Joint-line and/or periarticular tenderness (secondary anserine bursitis + medial ligament enthesopathy) >>> causing tenderness of the upper medial tibia
- Weakness and wasting of the quadriceps muscle
- Restricted flexion and extension + coarse crepitus
- Bony swelling around the joint line
- In knee OA >>> CPPD crystal deposition is common
- *This may result in** >>> more overt inflammatory component (stiffness, effusions) + super-added acute attacks of synovitis >>> which may be associated with >>> more rapid radiographic and clinical progression
Osteoarthritis >>> investigations
- A Plain X-ray of the affected joint >> often will show one or more typical features of OA
- For hip >>> Do non-weight beraingX-ray pelvis PA view
-
For knee >>> Do stan**dingX__-ray knee AP view >>> to assess >>> tibio-femoral cartilage loss
- A flexed skyline view >>> to assess patello-femoral involvement.
-
For spine >>> Plain X-ray spine
- If suspected spinal stenosis or nerve root compression >>> Do MRI
- Routine biochemistry: normal
- CBC/haematology: normal
- Autoantibody tests: usually normal
- Acute phase response: moderate
- Synovial fluid (aspirated from an affected joint)
- viscous
- A low cell count
Importance of plain x-ray in OA
Importance:
It is of value in assessing the severity of structural change >>>
which is helpful if joint replacement surgery is being considered.
Probable X-ray findings in hand OA
In hand:
- Joint space narrowing affecting the PIP and DIP
- In some OA-affected joints >>> typical > Articular subchondral and ‘gullwing’ appearances
- Osteophyte formation
Probable X-ray findings in knee OA
In knee:
- Advanced OA >>> almost complete loss of joint space >>> affecting both compartments
- Sclerosis of subchondral bone
- In severe patello-femoral OA >>> almost complete loss of joint space + lateral displacement of the patella
- If marked medial tibio-femoral OA >>>>> typical varus knee deformity
Probable X-ray findings in hip OA
In hip:
- Superior joint space narrowing
- Subchondral sclerosis
- Osteophytes
- Cysts
RA >>> pathophysiological chart
ACR (2010) criteria for diagnosis of Rheumatoid arthritis
Diagnosis by scale:
- Add score of categories A to D: If score ≥ 6/10 >>> Dx: Rheumatoid arthritis
- For not missing any criteria >>> Check through the criteria (from high score to low score) (= 5 to 0, 3 to 0, 1 to 0)
How is DAS28 scored and interpreted?
Count “the number” of “swollen and tender joints” in the upper limbs and knees >>> combine this with >>> the ESR + the patient’s assessment of the activity of their arthritis (on a visual analogue scale**: where, 0 indicates no symptoms and 100 the worst symptoms possible) → enter into a calculator (online) → generate a numerical score.
Interpretation: The higher the value → the more active the disease
