HIP OSTEOARTHRITIS
Joint Space Narrowing | Conservative First | THA When Failed
KELLGREN-LAWRENCE GRADING
Critical Must-Knows
- Groin pain with activity is classic presentation
- Radiographs: JSN, osteophytes, sclerosis, cysts
- Conservative FIRST: weight loss, PT, NSAIDs, injections
- THA when conservative fails and quality of life impaired
- Primary OA most common; secondary includes AVN, DDH, FAI
Examiner's Pearls
- "Internal rotation first motion lost
- "AP pelvis + lateral of affected hip for imaging
- "Young patients consider hip preservation before THA
- "Avoid THA in active infection, poor health that precludes surgery

Clinical Imaging
Imaging Gallery

Critical Exam Concepts
Groin Pain
True hip pathology causes GROIN pain. Lateral hip pain is often trochanteric bursitis. Buttock pain may be referred from spine.
Conservative First
Always trial conservative measures before THA. Weight loss, physiotherapy, walking aids, NSAIDs, injections. Surgery for failed conservative.
Radiograph Findings
Classic X-ray changes: Joint space narrowing, osteophytes, subchondral sclerosis, subchondral cysts. LOSS is mnemonic.
Young Patients
Consider hip preservation first in young patients - osteotomy, arthroscopy for FAI/labral tears. THA means revision surgery in future.
Hip OA vs Other Hip Conditions
| Condition | Pain Location | Key Feature | Imaging |
|---|---|---|---|
| Hip OA | Groin | Activity-related, stiffness | JSN, osteophytes |
| Trochanteric bursitis | Lateral | Point tenderness GT | Normal or bursitis |
| AVN | Groin | Risk factors (steroids, alcohol) | Crescent sign, collapse |
| Labral tear | Groin, clicking | Younger, mechanical symptoms | MRA shows tear |
LOSSOA X-ray Findings
Memory Hook:LOSS of cartilage causes all these changes!
DAFTSecondary OA Causes
Memory Hook:DAFT causes lead to secondary OA!
WIPEConservative Treatment
Memory Hook:WIPE out the pain with conservative treatment!
Overview and Epidemiology
Primary vs Secondary OA
Primary OA = no identifiable cause (wear and tear). Secondary OA = underlying condition (DDH, AVN, FAI, trauma, inflammatory arthritis). Secondary OA often affects younger patients.
Epidemiology
- 10% of adults over 60
- Increases with age
- More symptomatic in females
- Obesity major risk factor
- Leading indication for THA
Risk Factors
- Age: Primary risk factor
- Obesity: Increased joint loading
- Genetics: Strong family history component
- Occupation: Heavy labor
- Prior pathology: DDH, Perthes, SCFE, FAI
Pathophysiology and Anatomy
Hip Joint Anatomy
Ball and socket: Femoral head articulates with acetabulum.
Articular cartilage: Hyaline cartilage covers both surfaces. 3-4mm thick.
Labrum: Fibrocartilaginous rim deepens socket by 22%.
Capsule: Strong, reinforced by iliofemoral, pubofemoral, ischiofemoral ligaments.
Blood supply: MFCA (primary to head), LFCA, artery of ligamentum teres.
Rule Out Secondary Causes
In younger patients (under 50) with hip OA, always consider secondary causes - DDH, AVN, FAI, SCFE sequelae. These affect treatment planning and prognosis.
Classification Systems

Kellgren-Lawrence Grading
| Grade | Description | Clinical Correlation |
|---|---|---|
| 0 | No features of OA | Normal |
| 1 | Doubtful JSN, possible osteophytes | May be asymptomatic |
| 2 | Definite osteophytes, possible JSN | Mild symptoms |
| 3 | Moderate osteophytes, definite JSN, some sclerosis | Moderate symptoms |
| 4 | Large osteophytes, marked JSN, severe sclerosis, cysts | Severe, THA candidate |
Widely used, good inter-observer reliability for extremes.
Clinical Assessment
History
- Pain: Groin (true hip), activity-related
- Stiffness: Morning, improves with movement
- Function: Walking distance, stairs, ADLs
- Night pain: Advanced disease
- Impact on QoL: Work, recreation, sleep
Examination
- Gait: Antalgic, Trendelenburg
- ROM: Internal rotation lost first
- FABER/FADIR: Provoke pain
- Leg length: May be shortened
- Trendelenburg: Abductor weakness
Internal Rotation First
Internal rotation is the first motion lost in hip OA and often the most painful. Check ROM with patient supine and hip at 90 degrees flexion for accurate assessment.
Outcome Measures
Harris Hip Score: Classic outcome measure. Pain, function, ROM, deformity.
Oxford Hip Score: Patient-reported, 12 questions. Widely used.
HOOS: Hip Disability and Osteoarthritis Outcome Score. Comprehensive.
Investigations
Plain Radiographs
Views:
- AP pelvis (weight-bearing if possible)
- Lateral of affected hip (cross-table or frog-leg)
Findings (LOSS):
- Loss of joint space
- Osteophytes
- Subchondral sclerosis
- Subchondral cysts
May underestimate cartilage loss compared to MRI.
Weight-Bearing Films
Weight-bearing AP pelvis shows true joint space narrowing. Non-weight-bearing films may overestimate cartilage thickness. Always try to obtain weight-bearing views.
Management Algorithm

Hip OA Treatment Algorithm
Management Pathway
Clinical history and examination. Radiographs. Rule out secondary causes.
Weight loss, exercise, PT, NSAIDs, walking aids. Trial injections if needed.
If quality of life significantly impaired despite conservative measures, consider surgery.
THA (most common). Consider preservation surgery in young if appropriate.
Surgical Considerations

Indications for THA
Appropriate:
- Failed conservative treatment
- Significant functional impairment
- Pain affecting quality of life
- Radiographic evidence of OA
Relative contraindications:
- Active infection
- Poor health precluding surgery
- Unrealistic expectations
- Neuropathic joint (Charcot)
Age alone is not a contraindication.
Young Patient Counseling
Young patients (under 50) undergoing THA must be counseled about revision surgery probability. Current implants may last 20+ years but revision is likely within their lifetime.
Complications
| Complication | Conservative | THA |
|---|---|---|
| GI bleeding | NSAIDs risk | N/A |
| Infection | N/A | 1% (PJI) |
| Dislocation | N/A | 1-3% |
| DVT/PE | N/A | Despite prophylaxis |
| Leg length discrepancy | N/A | Measured and addressed |
| Loosening | N/A | Long-term, leads to revision |
Conservative Treatment Risks
NSAIDs have significant risks: GI bleeding, renal impairment, cardiovascular events. Use lowest dose for shortest time. Consider PPI cover. Acetaminophen is safer for chronic use.
Postoperative Care (THA)
THA Recovery
Mobilize day of surgery. DVT prophylaxis. Pain control. Precautions if posterior approach.
Discharge home 1-3 days. PT, gait aids. Wound care. Continue DVT prophylaxis.
Increase mobility. Wean walking aids. Drive when safe. Return to desk work.
Most return to pre-morbid activities. Low-impact sport allowed. Full function.
Dislocation Precautions
Posterior approach precautions: Avoid hip flexion greater than 90 degrees, internal rotation, adduction past midline. Duration varies (6-12 weeks). Anterior approach may have fewer precautions.
Outcomes and Prognosis
THA Outcomes
Survival: 95%+ at 15 years in correctly selected patients.
Function: Dramatic pain relief and functional improvement.
Satisfaction: Over 90% satisfied.
Revision risk: Higher in young, active patients. Polyethylene wear, loosening, infection main causes.
Non-Operative Outcomes
Natural history: Progressive deterioration. Rate varies.
Conservative treatment: Symptom management. Does not alter disease progression.
Evidence Base and Key Studies
Conservative Management of Hip OA
- Exercise and weight loss first line
- NSAIDs with caution
- Intra-articular steroid for flares
- THA when conservative fails
THA vs Conservative for Hip OA
- THA superior to conservative at 12 months
- Greater pain relief and function
- Quality of life improvement
- Cost-effective
Long-Term THA Survival
- 95% survival at 15 years
- Higher revision in young
- Cemented vs uncemented similar in elderly
- Hybrid fixation common
Intra-articular Steroids for Hip OA
- Short-term pain relief (weeks)
- No disease modification
- Repeated injections safe
- Consider for flares
Exercise for Hip OA
- Land-based exercise reduces pain
- Improves function
- Water-based exercise also effective
- Safe and recommended
Exam Viva Scenarios
Practice these scenarios to excel in your viva examination
Scenario 1: Classic Hip OA
"A 68-year-old woman presents with 2 years of progressive right groin pain worse with walking and stairs. She has stiffness in the morning for 20 minutes. X-rays show joint space narrowing, osteophytes, and subchondral sclerosis. She has not tried any formal treatment. What is your management?"
Scenario 2: Young Patient with OA
"A 42-year-old active man presents with bilateral hip pain and stiffness. X-rays show moderate bilateral hip OA with acetabular dysplasia (CE angle 18 degrees). He is frustrated with symptoms affecting his tennis. What is your approach?"
Scenario 3: Failed Conservative Treatment
"A 72-year-old woman has tried physiotherapy, lost 8kg, uses a walking stick, and has had two steroid injections over 18 months. She still has significant right hip pain limiting her to walking 200m and disturbing her sleep. X-rays show bone-on-bone changes. She asks about her options. What would you advise?"
MCQ Practice Points
Classic Presentation
Q: Where does true hip pathology cause pain? A: GROIN. Lateral pain = trochanteric bursitis. Buttock pain = sacroiliac or lumbar spine.
First Motion Lost
Q: What is the first motion lost in hip OA? A: Internal rotation. Often most painful as well. Test at 90 degrees flexion.
X-ray Findings
Q: What are the radiographic features of OA (LOSS)? A: Loss of joint space, Osteophytes, Subchondral Sclerosis, Subchondral cysts.
Kellgren-Lawrence
Q: What is Kellgren-Lawrence Grade 4? A: Large osteophytes, marked joint space narrowing, severe sclerosis, cysts, bone-on-bone. End-stage OA.
First Line Treatment
Q: What is first-line treatment for hip OA? A: Conservative: weight loss, exercise, physiotherapy, acetaminophen, walking aids. NSAIDs with caution.
THA Survival
Q: What is 15-year survival of THA? A: Greater than 95% in correctly selected patients. Higher revision in young, active patients.
Australian Context
Clinical Practice
- High THA rates per capita
- National Joint Replacement Registry (AOANJRR)
- Registry data guides implant selection
- Conservative treatment emphasized
- Mostly uncemented THA
Funding and Access
- Public system THA available
- Variable wait times (12-24 months)
- Private faster access
- Medicare/private insurance covers
- PT accessible via Medicare
Orthopaedic Exam Relevance
Hip OA is extremely common in viva. Know conservative treatment first, THA indications, and be able to consent a patient. Discuss approaches, complications, and manage expectations appropriately.
HIP OSTEOARTHRITIS
High-Yield Exam Summary
Presentation
- •Groin pain (true hip)
- •Activity-related, improves with rest
- •Morning stiffness (less than 30 min)
- •Internal rotation first lost
Radiograph (LOSS)
- •Loss of joint space
- •Osteophytes
- •Subchondral Sclerosis
- •Subchondral cysts
Conservative (WIPE)
- •Weight loss
- •Injections (steroid)
- •Physiotherapy
- •Exercise and NSAIDs
Kellgren-Lawrence
- •Grade 1: doubtful narrowing
- •Grade 2: definite osteophytes
- •Grade 3: definite narrowing
- •Grade 4: bone on bone
THA Indications
- •Failed conservative treatment
- •Significant functional impairment
- •Impact on quality of life
- •Radiographic OA
Secondary Causes (DAFT)
- •DDH (dysplasia)
- •AVN
- •FAI
- •Trauma
