Upper Limb: RA

Question 1

What percentage of the adult population in the developed world is affected by RA?

Answer 1

0.5-1% of the adult population in the developed world is affected by RA.

Question 2

What percentage of RA patients have hand involvement?

Answer 2

> 90% have hand involvement.

Question 3

What percentage of RA patients have limitations in activities of daily living (ADL)?

Answer 3

30% have limitations in ADL.

Question 4

What is a susceptibility gene associated with RA?

Answer 4

1. HLA DRB1
2. PTPN22 (The PTPN22 gene encodes a protein tyrosine phosphatase that regulates T cell signaling and interferon production.)

Question 5

What are some environmental factors contributing to RA?

Answer 5

Recurrent exposure to exogenous, endogenous or commensal viral, bacterial or other agents;

Smoking (doubles risk).

Question 6

What is citrullination in the context of RA?

Answer 6

Citrullination is the process where arginine is replaced by citrulline.

Question 7

What are autoantibodies associated with RA?

Answer 7

ACPA (Anti-Citrullinated Protein Antibodies) and RF (Rheumatoid Factor).

50-80% of patients are positive for RF, ACPA or both

Most ACPA positive patients are also RF positive

RF is IgM or IgA directed against the Fc portion of IgG -> form immune complexes that activate the compliment cascade, causing inflammation

Question 8

What is the progression of RA symptoms?

Answer 8

Asymptomatic synovitis followed by symptomatic arthritis.

Question 9

What percentage of RA patients are positive for RF or ACPA?

Answer 9

50-80% of RA patients are positive for either RF, ACPA, or both.

Question 10

What is RF in the context of RA?

Answer 10

RF is IgM or IgA directed against the Fc portion of IgG.

Question 11

What do immune complexes formed by RF do?

Answer 11

They activate the complement cascade leading to inflammation.

Question 12

Are most ACPA positive patients also RF positive?

Answer 12

Most ACPA positive patients are also positive for RF.

Question 13

What structures are affected in Rheumatoid Arthritis (RA)?

Answer 13

Skin: Rheumatoid nodules
Synovium: proliferation
Tendon: ruptures
Joints: arthritis
Nerves: entrapment
Vessels: Vasculitis

Question 14

What are the three phases of RA categorization according to Lister?

Answer 14

1. Proliferation
2. Destruction
3. Reparative

Question 15

What occurs during the Proliferation phase of RA?

Answer 15

Synovial swelling leading to pain, reduced ROM, nerve compression or triggering

Question 16

What happens during the Destruction phase of RA?

Answer 16

Synovial erosions lead to tendon ruptures, bone erosions, capsular and ligamentous weakness

Question 17

What are the effects of the Reparative phase of RA?

Answer 17

Fibrosis leads to restrictive tendon glide, joint contracture and deformity

Question 18

What are the pathophysiological causes of tendon ruptures in RA?

Answer 18

1. Direct invasion of the pannus
2. Attrition rupture secondary to bony prominences
3. Listers tubercle => EPL rupture
4. Ulnar head => EDC rupture (Vaughn Jackson)
5. Scaphoid tubercle => FPL rupture (Mannerfelt)

Question 19

What is the order of frequency for tendon ruptures in RA?

Answer 19

1. Extensors of RF/LF (Vaughn Jackson)
2. EPL
3. Other extensors
4. FPL (Mannerfelt)
5. Other flexors

Question 20

What are the radiological findings in RA?

Answer 20

1. Joint Space Narrowing
2. Bone Erosion
3. Subluxation
4. Ankylosis
5. Subluxation and mutilating changes

Question 21

What are the wrist features of RA?

Answer 21

1. Ligamentous instability
2. DRUJ instability
3. Volar subluxation ECU
4. Dorsal displacement Ulna
5. Rupture extensor tendons (EPL, EDC)
6. Radial deviation MC
7. Subluxation of carpus/palmar dislocation of the carpus

Question 22

What are the metacarpal changes in RA?

Answer 22

Ulnar deviation of the digits due to:
1. MCPJ synovitis
2. Stretching of the radial sagittal bands
3. Radial dislocation of the MC
4. Ulnar dislocation of the extensor tendons
5. Tightness of the ulnar intrinsic muscles

Question 23

What are the types of Swan Neck deformity according to Nalebuff?

Answer 23

Type I: PIPJ Flexible
Type II: PIPJ limited in certain MCPJ positions secondary to intrinsic tightness
Type III: PIPJ fixed in hyperextension
Type IV: as for type III but with joint changes on XR

Question 24

What is the Z mechanism in RA

Answer 24

When a joint adopts angulation, the joint either side goes the opposite way provided the joints either side allow it.

Pathology: Consequence

PIP disease, Intrinsic tightness,FDS disease: Hyperextension PIPJ + flexion DIPJ => Swan Neck

PIPJ disease,Central slip attrition, Lateral band volar subluxation/dislocation: Flexion at PIPJ, hyperextension at DIPJ =>
Boutionniere’s

Ulnar head disease, Radiocarpal articular loss: Radial deviation at wrist => ulnar drift of the fingers

MPJ disease in the thumb: Volar subluxation MCPJ + hyperextension IPJ => Boutionniere’s

Question 25

Describe a classification system for Boutionniere’s

Answer 25

Nalebluff + Millender:

Type I: PIPJ extensor lag 10-15 degrees, passively correctable
Type II: PIPJ extensor lag 30-40 degrees, passively correctable
Type III: Fixed flexion deformity at PIPJ

Question 26

Describe a Classification for RA thumb deformities

Answer 26

Modified Nalebluff Classification
* Type 1: Boutionniere
○ Attenuation of EPB
○ Stretching of MCPJ hood
○ Subluxation of EPL
* Type II: Boutionniere + Swan neck
* Type III: Swan neck of 2nd MC, extrinsic plus
* Type IV: Gamekeepers thumb
○ UCL disruptuioin due to MPJ synovitis
* Type V: Swan neck
○ Due to chronic synovitis
* Type VI: Arthritis Mutilans
○ Marked skeletal collapse due to loss of bone substance

Question 27

What are the surgical options for RA hand patients

Answer 27

Nearly all surgical procedures for RA hand fall into one of 5 groups:
1. Synovectomy
2. Tenosynovectomy
3. Tendon surgery
4. Arthroplasty
5. Arthrodesis

Synovectomy:
* Indicated for mild disease controlled by drugs with persistent synovitis in one or two joints
* Contra-indicated in rapidly progressive joint disease
Frequent observation required so reconstruction can be performed before development of severe deformity

Question 28

What are the medical/anaesthetic considerations when operating on RA patients?

Answer 28

Medical Considerations
* C spine involvement - implications for GA (consider RA instead)
* TMJ involvement can make intubation difficult (again RA better)
* Pulmonary involvement (due to disease itself - pulmonary nodules/interstitial fibrosis, or due to the anti-rheumatic therapy)
* Felty syndrome (splenomegaly and neutropenia) -> increased risk of infection
* Drug therapy
○ NSAID
○ DMARDs
§ Methotrexate
□ Can affect liver function (alter choice of anaesthetic)
§ Leflunomide (Arava)
§ Sulfasalazine
§ Hydroxychloroquine
§ Biological DMARDS
□ Intefere with the action of TNF alpha, IL-1 or IL-6 and T-cell costimulation or deplete B lymphocytes
□ Eg: infliximab, etanercept, adalimumab, anakinra, tocilizumab, abatacept, and rituximab
§ Systemic corticosteriods
□ Can delay wound healing

Question 29

What are the priorities for hand surgery in RA?

Answer 29

1. Alleviate pain
   
   2. Improve function
   3. Retard progression fo disease and /or prevent loss of function
2. Improve appearance

Question 30

Are you aware of any classification systems for RA?

Answer 30

Classification criteria by classified by the American College of Rheumatology (ACR) and the European Alliance of Associations for Rheumatology (EULAR):

1. Joint involvement: The number of joints affected, including large joints and small joints
2. Serology: The presence of rheumatoid factor (RF) and anticitrullinated protein/peptide antibodies (ACPAs)
3. Acute-phase reactants: The levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)
4. Duration of symptoms: How long the patient has had symptoms

A score of 6+ indicates RA.

Pts can be classified as having RA if they have typical erosions on XR also

Question 31

What are some of the extra-articular features of Rheumatoid Arthritis?

Answer 31

1. Ocular (sleritis, episcleritis, uveitis, Sjogrens syndrome [triad of dry eyes, dry mouth, RA])
2. Neurological (peripheral neuropathy, nerve entrapment syndromes, cervical myelopathy, mononeuritis multiplex)
3. Haemopoetic (normocytic-normochromic anaemia of chronic disease, Felty’s syndrome [RA associated with splenomegaly and neutropenia],
4. Cardiovascular (pericarditis, pericardial effusion, valvular heart disease, conduction defects)
5. Pulmonary (Pulmonary nodules, pleural effusions, fibrosing alveoli’s, Caplan’s syndrome [RA in combination with pneumoconiosis, manifesting as intrapulmonary nodules])
6. Renal (RA does not directly affect the kidneys, secondary involvement from drug side effects and amyloidosis)
7. Cutaneous (vasculitic rashes and ulcers, pyoderma gangrenosum, thinning of skin secondary to steroids, rheumatoid nodules)

Question 32

What are the medical options for managing rheumatoid arthritis?

Answer 32

1. Disease modifying anti-rheumatic drugs (DMARDS)
   - first line
   - reduce inflammation, swelling and pain, reduce acute phase markers, limit progressive joint destruction
   - eg methotrexate, sulfasalazine, hydroxychloroquiine
   - SE include hepatotoxicity, blood dyscarias, interstitial lung disease
2. biological agents
   - TNF alpha inhibitors (Adalimumab [Humira], Etanercept [ Enbrel], Golimumab [Simponi], Infliximab [Remicade]
   -IL-1 inhibitors (Anakinra [Kineret])
   -IL-6 inhibitors (Tocilixumab [RoActemra])
   -T-lymphocyte inhibitors (Abatacept [Orencia])
   - B lymphocyte inhibitors (Belimumab [Benlysta])
3. Glucocorticoids. 2 main indications in RA:
   a. short term control of flares whilst DMARDS are adjusted
   b. Intra-articular injection for individual active joints
4. analgesia
5. other supportive therapy (exercise/physio/psychology/control co-morbidities/education)