Monoarticular Pain 3. Osteoarthritis

Miss Joanna Richards MBChB BSc MRCS Trauma & Orthopaedic Registrar

Birmingham Orthopaedic Training Programme

• Lecture 1: Introduction • Lecture 2: Septic Arthritis

• Lecture 3: Osteoarthritis: • Case

– History – Examination – Investigations – Differential diagnosis

• Condition overview • Management • Complications • Risk Factors • Pathophysiology • Comparison with normal joint on ageing

• Lecture 4: Crystal Arthropathies

Module Overview

Case • PC

– 60 year old lady presents with right knee pain

• HPC

– Occurring most days in the past few months; much worse today

– Gradual onset; worse in the morning with associated stiffness

– Over anterior aspect of knee; worse when going up and down stairs

– Buckling sensation in the right knee

• PMHx

– Nil of note

• SHx

– Landscape gardener

Examination

• General inspection: – Steady by slow gait; favouring left side

– Increased BMI

• Focused examination: – Look

• Minimal swelling

– Feel • Small effusion with diffuse crepitus; medial joint line

tenderness

– Move • Limited flexion (90)

Investigations

• Bloods

– FBC, U&Es, CRP, ESR, urate levels

– Blood cultures

• Joint aspiration

– Send for MC&S, urgent gram stain and crystals

• Imaging

– X-ray

– USS

Osteoarthritis

• Degenerative synovial joint disorder – Failure to maintain homeostatic balance of cartilage

matrix synthesis and degradation

– Progressive loss of articular cartilage

• Commonly affects knees

• Presents with joint pain and stiffness – Typically worse with activity

• Slightly more common in females

• Can be primary or secondary

Presentation

• History – Symptoms – Standard history of pain such as SOCRATES

• Remember duration of symptoms

– Impact on life- work, activity of daily living

• Examination – Signs – Limb alignment

• Altered mechanical axis

– Remember to examine joint above and below joint in question • Pain can be referred

Signs and Symptoms

• Symptoms – Pain worsens with activity and results in limitations – Chronic onset – Stiffness on resting; eases gradually on movement

• Signs – Initially none – Swelling with activity – Deformity due to osteophytes – Crepitus – Reduced range of motion – New use of walking aid

Diagnosis

• Can be made clinically without investigations if a person1

– If 45 years old or over

– Has activity related joint pain

– Has morning joint- stiffness lasting less than 30 minutes

1) Osteoarthritis: care and management in adults; NICE Clinical Guideline (February 2014)

Imaging

• Radiographs – Need weight bearing films

• Cannot see joint space narrowing on non weight bearing films

– 2 views • Anteroposterior (AP) and lateral of joint

• Findings – Joint space narrowing – Subchondral sclerosis (thickening) – Osteophyte – Bone cysts

Preserved joint space

Joint space narrowing

Osteophyte

Subchondral sclerosis

Bone cyst

Image from http://www.mattdriscollmd.com/knee-arthritis-matthew-driscoll-sports-medicine.html (accessed March 2018)

Describe the Radiographs

Patient ID: 12345678 DoB 12/03/1945 10/09/2017

AP Lateral

Patient ID: 12345678 DoB 12/03/1945 10/09/2017

AP Lateral

AP and lateral weight-bearing radiographs of the left knee of 73yo Patient 12345678 taken 10/09/2017 showing osteoarthritis indicated by the joint space narrowing (worse on the lateral side), osteophytes associated with the tibia and patella mainly and subchondral sclerosis.

Management

• Nonoperative (conservative) – Weight loss/ weight management programmes – Physiotherapy/ activity modification programmes – Education – Analgesia

• Paracetamol; NSAIDs

– Joint injections • Steroids, anaesthetic • Can also be useful for diagnosis

• Operative – Arthroscopic debridement – Joint arthroplasty (replacements) or joint fusion – Corrective osteotomies to restore mechanical alignment

Complications

• Disability

• Immobility

• Chronic pain

• Joint destruction

Risk Factors • Modifiable

– Articular trauma • Especially with resulting misaligned articular surface

– Occupation and recreational joint stress – Muscle weakness – Large body mass – Increased joint laxity

• Non-modifiable – Gender

• females >males

– Increased age – Genetics – Developmental or acquired deformities

• Hip dysplasia • Slipped upper femoral epiphysis • Legg- Calve- Perthes disease

– See ‘The Limping Child’ talk for more information

Pathophysiology

• Articular(hyaline) cartilage – Failure of homeostatic balance of cartilage matrix

synthesis and degradation – Increased water content causes proteoglycan

reductions and collagen abnormalities resulting in loss of orientation and organisation

• Synovium and capsule – Becomes inflammed, hypervascular and increasingly

thick as severity increases

• Bone – Subchondral bone remodelling leads to lytic lesions

with sclerotic edges, bone cysts and osteophyte formation

Comparison of Normal Aging Joint Changes vs Osteoarthritis

Feature Aging Osteoarthritis

Water Content Decreased Increased

Collage Same Disorganised

Proteoglycan content Decreased Decreased

Proteoglycan synthesis Same Increased

Chondrocyte size Increased Same

Chondrocyte number Decreased Same

Modulus of elasticity Increased Decreased

Summary

• Degenerative disease of synovial joint

• Common chronic disease on advancing age characterised by joint pain on activity and stiffness settling within 30 minutes

• Analgesia, physiotherapy and joint replacement/ fusion surgery

• 4 classic signs on weight bearing radiographs – Joint space narrowing – Subchondral sclerosis – Subchondral cysts – Osteophytes

References

• BMJ Best Practice (available online at bestpractice.bmj.com; accessed February 2017)

• Oxford Handbook for the Foundation Programme (2nd edition)

• Ritchie Chalmers, C. Parchment Smith, C. MRCS Part A: Essential Revision Notes (book 1) (PasTest 2012)

• www.orthobullets.com

Thank you!

Presentation available on https://www.bon.ac.uk