Table of contents
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Osteoarthritis
- The most common MSK problem. (80% age >55yo, and 90% >65yo)
- Biomechanical process where joints respond pathologically to mechanical stress
- Causes cartilage degradation and changes in subchondral bone.
- F>M (2:1)
Risk Fact ors
- Typically any overuse, trauma, genetics, or increased load (obesity) are risk factors
- Example:
- Age, Female, Obesity
- Occupation, Sports Activities, Previous Joint Injury
- Muscle Weakness, Proprioceptive deficits
- Genetic Elements
- Acromegaly
- CPPD Disease
- Often depends on joint involved
- Knees: Obesity is biggest risk factor
- Hands: Genetics is biggest risk factor
- Obesity is a modifiable risk factor
Joints Involved
- Usually load-bearing joints
- Any joint that has previous trauma/injury/inflammation
- Hand: PIP and DIP involvement (+bone spurs cause Bouchard's and Heberden's nodes)
- Thumb: CMC joint 1st digit... squaring of contour of joint.
- Knees: Usually on weight bearing - asymmetric joint space narrowing (medial usually), causes valgus/varus deformity
- Hip: Groin Pain
Clinical Features
- Presentation:
- Peripheral Joints
- Pain, loss of function
- Although "non-inflammatory", but inflammation can occur in flares.
- Inflammatory episodes correlate with progression
- Worse with activity (unlike RA)
- Morning stiffness can occur, lasts < 30min
- Sx depend on joints:
- Hip --> Groin Pain (not lateral)
- Knee --> On weight bearing
- Patello-femoral Joint --> climbing/descending stairs, or sitting in chair for long time
- Axial Involvement
- Back pain!
- Pain not due to joint disease, but due to nerve root foraminal narrowing or spinal compression inside canal --> radiculopathy, sciatica, pseudoclaudication, myelopathy
- Peripheral Joints
- Physical Exam
- Inspection
- Valgus Deformity (lateral joint space narrowing)
- Varus Deformity (medial joint space narrowing) [more common]
- Bony Enlargement
- Palpation: Temperature, Pulses,
- Hand
- Ulnar Deviation
- Ulnar styloid prominence
- MCP, PIP swelling or wrist swelling, r/o dactylitis
- Subluxation particularly of the MCP joints
- Swan neck or boutonniere's deformity
- Z deformity
- Nodules and ganglion cysts
- Special tests
- CMC arthritis vs. DeQuervain's Synovitis (Finklestein's test)
- Joint line tenderness (esp medial compartment)
- etc
- Inspection
Imaging Findings
- 1. Asymmetric Joints Space Narrowing (load bearing)
- 2. Osteophytes
- 3. Subchondral Sclerosis (joint compensating for cartilage damage).
- 4. Bone Cyst Formation
- 5. Eburnation
- Spine:
- Cystic Changes
- Disc Narrowing + collapse
- Facet osteophytes
- Spondylolisthesis (Spine misalignment)
- Scoliosis/Kyphosis
- Knee: Medial compartment joint space narrowing
- NOTE: Radiographic severity ≠ severity of symptoms
- Image Source: http://www.physio-pedia.com/
Classification
- Erosive OA
- OA with lots of inflammation and erosions. On X-Ray looks like psoriatic arthritis.
- Usually DIP and PIP.
- Joints usually red/warm, but will have OA bony enlargement.
- Primary OA
- Axial skeleton, weight-bearing joints (hip/knee joints), hand (IP and CMC joins).
- Secondary OA
- Due to joint injury or metabolic diseases (i.e. prev damaged by inflammatory conditions)
- Usually, OA features in "wrong joints" for OA
- Most common:
- Chondrocalcinosis
- Hemochromatosis
- Diffuse Idiopathic Skeletal Hyperostosis (DISH)
- Calcification of spinal ligaments --> large flowing osteophytes.
- Discs are spared
- Thoracic involvement is earliest (most common)
- Enthesis calcification (where tendons/ligaments insert) can occur
- Occurs in Obese men > 50yo
- Can be asymptomatic, or have stiffness and decreased ROM of spine (mostly thoracic)
- Diagnosis
- In Imaging: flowing osteophytes across 4 contiguous vertebrae
- Difference Ankylosing Spondylitis
-
Feature DISH Ank Spond Osteophytes/Syndesmophytes Horizontal ("Flowing") curve out/in Vertical Location Thoracic Spine & patchy distribution SI joints and Lumbar Spine
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- Calcification of spinal ligaments --> large flowing osteophytes.
- Disease Severity
- WOMAC
- Western Ontario Mcmaster University OA Index
- Functional assessment
- WOMAC
Treatment
- Non-Pharmacological
- ADAPT Trial - Arthritis Diet Activity Promotion Trial
- Impact of weight loss, exercise combo therapy vs. healthy lifestyle for OA
- Found diet and exercise groups had less pain and more function at 6mo.
- Weight loss and exercise (combined) had the best outcomes.
- Exercise - none is bad, high impact competitive sports can predispose to OA
- Walking (Activities such as walking are good activities)
- Water Therapy (well tolerated (warm water pool)
- Weight Reduction (Risk factor, and increases symptoms. Even 10lb helps substantially)
- Biomechanics (Unloading joint)
- Unloading Knee/Hip Braces
- Braces for hip/knee (biomechanics)
- Brace unloads affected joint, and distributes load to the other extremity.
- Works only with asymmetric arthritis obviously.
- (NOTE: Wedge shoe inserts = no benefit)
- Using Caine
- Unloads affected joint
- Hand
- Large grip utensils, keyholders,
- Unloading Knee/Hip Braces
- Diet
- Weight loss!
- AVOID high saturated fat diet (avoid fructose!!)
- More fatty acids (Tumeric has some evidence)
- Patient Education
- Arthritis Foundation Foundation Self-Mgmt Program (participation = less disability)
- ADAPT Trial - Arthritis Diet Activity Promotion Trial
- Pharmacological
- Topical (some relief)
- Topical diclofenac: Pennsaid lotion 1.5% (40 drops to knee)
- Voltaren emugel is OTC: is also diclofenac but in ointment form
- Lidocaine patches (super expensive), Lidocaine cream (cheaper)
- Topical Arnica, ice, heat
- Capsaicin topicals (hot peppers alter nerve endings)
- Analgesics
- Tylenol (safest)
- NSAIDs (have evidence if don't respond to acetaminophen)
- Cox2 Inhibitors (high risk of GI s/e, avoid in high CV risk)
- Articular Injection
- Only when single joint or few joints (worse than other joints) + limits function
- Cortisone Injection
- Must do every 3-4mo (stops working after 2-3 times)
- Drawbacks:
- Soft Tissue Atrophy
- Stops working after 2-3 times
- Infection/bleeding complications are rare
- Hyaluronic acid injections:
- most beneficial in mild-to-mod OA (EXPENSIVE - $450/needle), lasts 6mo
- Unclear how it works (lubrication?), substance cleared from joint in 24-48hrs
- Clinical Trials: modest effect, but statistically significant
- Platelet rich plasma injections: likely beneficial
- Opioids
- Only role for acute severe pain. NOT chronic pain.
- Nerve blocks, steroid injection first
- Surgery (Joint Replacement)
- Joint Replacement is HIGHLY EFFECTIVE, but due to morbidity it is last line.
- Arthroscopy NOT INDICATED. (RCT = no effect)
- 90% significant functional improvement
- Knee replacement longer recovery than hip
- Back to driving in 6w, fully recover by 6mo, many patients say takes 12mo to get full benefit.
- PT post-surgery is CRITICAL
- MUST be motivated to participate in PT, and have good social support!
- Joint Replacement is HIGHLY EFFECTIVE, but due to morbidity it is last line.
- Topical (some relief)
- NOTE:
- Glucosamine: no benefit in large studies (advise to try it for few months, if no help can stop)
- Hyaluronate injection: Only indicated for mild-to-moderate arthritis.
- Knee Arthroscopic Lavage/debridement: RCT shows no benefit. (unless meniscal tear (catching/locking).
- Osteotomy (removes wedge of bone to realign axial load on joint) --> studies show improvement in pain in young patients, but likely similar benefit as maximal medical therpay.
- Accupuncture - no benefit
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