Approach to knee pain Flashcards
1
Q
Learning Outcome:
A
- Degenerative
- Osteoarthritis - Inflammatory
- Rheumatoid arthritis
- Psoriatic arthritis
- Gout
- Pseudogout
- Reactive arthritis (Reiter’s Syndrome)
- SLE - Infection
- Septic arthritis
- Tuberculous arthritis - Tumour
2
Q
Osteoarthritis pathology
A
- Definition:
- chronic disorder of synovial joint
- destruction: progressive softening and disintegration of articular cartilage
* reduce joint space
* mild synovitis
- repair: growth of cartilage and bone at joint margin
* osteophytes formation
* subchondral sclerosis
* subchondral cyst
* capsular fibrosis - Epidemiology:
- 50% in people age over 50yo
- common joints: fingers, hip, knee and spine
- uncommon joints: shoulder, wrist, ankle, elbow - Etiology
i. primary
- idiopathic
- senile
- post-menopausal
ii. secondary
- inflammatory: RA, Gout
- infection: SA, TB
- trauma: Meniscal injury
- tumors
- genu varus deformity
- SCFE, Perthes - Grading of chondral damage: Outerbridge Classification
I - Cartilage softening (increase water content from 80 to 90%)
II - Partial thickness defect less than 1.5 cm diameter (subchondral bone not yet exposed)
III - Partial thickness defect more than 1.5 cm diameter (subchondral bone not yet exposed)
IV - Exposed subchondral bone - Kellgren and Lawrence Grading (Radio)
I - Doubtful joint space narrowing (JSN)
II - Definite osteophytes and possible JSN
III - Definite JSN, osteophytes and some sclerosis
IV - Severe JSN, marked osteophytes and sclerosis - Complication
i. Posterior capsule herniation (Baker’s cyst)
ii. Loose bodies (cartilage and bone fragments)
iii. Osteoporosis (disuse) - Knee pain in osteoarthritis
i. bone pressure (vascular congestion and intraosseus hypertension)
ii. mild synovitis
iii. stretching capuslar fibrosis
iv. muscular fatigue - Variants in osteoarthritis
i. Mono/Pauciarticular (classic oa)
- one or two joints
- usually secondary (known causes)
ii. Polyarticular
- most common form
- involvement of CMC, big toe MTP, ITP, DIP (Herberden’s), PIP (Bouchard’s)
iii. Rapidly destructive
- analgesic arthropathy
- calcium pyrophosphate dihydrate crystal deposition in elderly women
3
Q
Osteoarthritis diagnosis
A
Hx
- Knee pain
- gradual onset
- deep, aching
- increase when walking, up stairs, squatting (MC), down the stairs (PFC)
- relieve with rest/analgesics
- late in the evening/afternoon
- continuous (severe) - Morning stiffness
- due to stretching of fibrosed capsuld
- relieve after less than 30 mins - Swelling
- intermittent: effusion
- continuous: capsular thickening, osteophyte - Loss of function
- restriction of day task - Locking
- if there is loose bodies - Clicking, grinding sensation
Pe
i. Look
- scars
- genu varus deformity
- quadriceps wasting
- antalgic gait
ii. Feel
- mild effusion
- crepitus
- patella facet, grinding tenderness
- joint line tenderness
- osteophytes
- capsular thickening
iii. Move
- fixed flexion deformity
- extensor lag
iv. Special test
- ligamentous laxity on varus stress test
v. Examine other joint: hand, hip, spine
X-Ray
- Standing AP
i. Assymmetrical narrowing of joint space (medial)
ii. Marginal osteophytes
iii. Subchondral sclerosis
iv. Subchondral cyst close to articular facets
v. Bone destruction, fusion (late)
Bone scan
- increase activity due to increase vascularity and bone formation (not needed)
- European League Against Rheumatism (EULAR)
- American College of Rheumatology 1986 Criteria
4
Q
Osteoarthritis Management
A
Principles of management:
- Maintain movement and muscle strength
- Protect joint from overload
- Relieve pain
- Modify daily activity
Conservative Tx
- Joint-protective exercise to increase muscle strengh: swimming
- Offloading:
- weight reduction
- short absorbing shoes/orthosis
- use walking aids - Analgesics
- PCM -> topical or oral NSAIDS -> intraarticular corticosteroids - Nutraceutical:
- Glucosamine sulfate
- Diacerein
- Chondroitin - Viscosupplementation: Intraarticular hyaluronic acid (reduce pain)
Surgical Tx
- Joint debridement (loose bodies, cartilage tags, interfering osteophytes)
- High tibial osteotomy (unicompartmental OA)
- redistribute loads
- vascular decompression - Joint replacement/Arthroplasty
- 15 years period (usually in elderly)
i. Unicondylar (UKR)
ii. Patellofemoral knee
iii. Bilateral knee
iv. TKR - Arthrodesis
- small joints
5
Q
Rheumatoid Arthritis pathology
A
- Epidemiology:
- female more common (3:1)
- 30-50 yo - Definition
- systemic chronic autoimmune disease (Type 3, 4: antibodies and T-Cells)
- characterized by:
i. articular: synovitis, articular cartilage destruction, joints, tendon sheath inflammation
ii. extraarticular:
- Vasculitis
- Atherosclerosis
- Nodules (lung, pericardium)
- Anaemia/pancytopenia
- Splenomegaly
- Peripheral neuropathy (weakness, nerve compression)
- Amyloidosis
- Scleritis
3. Stages I - Preclinical (Raised ESR, CRP, RF) II - Synovitis III - Joint, tendon, articular destruction (granulalation tissue invasion, bone resorption) IV - Deformity
- Complication
i. Joint contractures
ii. Joint rupture
iii. Steroids: Infection, Cushing
iv. Atlantoaxial instability
v. Vasculitis
vi. Amyloidosis - Prognosis
- 60% intermittent and remission
- 20% severe erosion within 5 years
- 10% completely disabled
- death due to IHD
6
Q
Rheumatoid Arthritis diagnosis
A
Hx
- Joint pain
- PIP, MCP -> wrist -> feet -> knee -> shoulders
- symmetrical
- intermittent
- disturb ADL grooming, dressing - Morning stiffness
- last more than 30 mins
Pe
- Joint deformity
- ulnar deviation
- radial volar wrist deviation
- valgus feet, clawed toes
- valgus knee - Swelling/Nodules
- back of elbow, pip
- firm rubbery in consistency - Others: Vasculitis, Muscle wasting, Lymphadenopathy, Scleritis, Peripheral sensory neuropathy, Myopathy, pulmonary fibrosis
Blood
- anaemia
- ESR, CRP (active phase)
- serology: RF (prognostic factor), anti-CCP (more specific)
X-Ray Hands, Feets, Knee - soft tissue shadow - periarticular osteoporosis - marginal bone erosion - narrowing of joint space Cervical spine - atlantoaxial subluxation
7
Q
Rheumatoid Arthritis management
A
Medical Mx
i. Control inflammation rapidly
- corticosteroids tapering dose
ii. DMARDs
- methotrexate
- +/- sulfasalazine, hydroxychloroquine
- Gold, penicillamine (rarely)
Surgical Mx
- Synovectomy
- Tendon repair/replacement
- Arthrodesis/arthroplasty/Osteotomy (OA changes)
8
Q
Reiter’s Syndrome
A
- Definition: Clinical triad of urethritis, arthritis (large joint forst -> sacroilitis, spondylitis) and conjunctivitis occuring weeks after GUT, dysentery infection
- Epidemiology
- men more common than women (10:1)
- age 20-40 yo - Pathogens
- Shigella
- Salmonella
- Campylobacter
- Yersinis enterocolitica
- Chlamydia trachomatis
9
Q
Reiter’s Syndrome diagnosis
A
Clinical features
- Acute phase
- asymmetrical lower limb joint pain (knee, ankle, tarsal, toe)
- inflammation signs (hot, swollen)
- conjunctivitis
- urethritis
- backpain - Chronic phase
- sacroilitis
- spondylitis
++ anterior uveitis, glaucoma
X-ray
- similiar to ankylosing spondylitis
10
Q
Gout pathology
A
- Definition: Disorder of purine metabolism, deposition of urate salts in joints and periarticular tissue leads to
- recurrent acute synovitis
- cartilage degeneration
- renal dysfunction
- uric acid urolithiasis - Epidemiology
- more than 30 yo
- male more than female (20:1) - Classification
i. Primary (95%)
ii. Secondary (5%)
- myeloproliferative disease
- diuretics
- renal failure
11
Q
Gout diagnosis
A
Hx
- joint pain
- MTP of big toe (podagra), ankle, fingers, olecranon bursa
- signs of inflammation - risk factor
- high purine diets: seafood, red meats
- obesity
- alcoholics
- hupertensive - Tophi
- joints
- olecranon
- ear pinna - Urate stones
X-Ray
- joint space narrowing
- punched out periarticular erosion (excavating)
