This is a practice OSCE station for UKMLA content.
Contents
How to use
Candidate:
- Read the brief below (1 minute).
- Take a history and perform a focused examination (7 minutes).
- Answer EITHER viva questions OR patient questions (3 minutes).
Patient/Examiner:
- Familiarise yourself with the history and examination findings.
- After completing the history, EITHER viva the candidate OR act as the patient.
Candidate brief
You are the Foundation Year 2 doctor in a GP practice.
A 28-year-old man, James Walker, presents with lower back pain.
Please take a focused history, examine the relevant area and answer the following questions.
Presenting Complaint:
- Back pain.
- Quote – “I’ve had this annoying back pain for over a year now. It’s not improved since it initially came on and I am now finding it difficult to exercise as freely as I used to.”
History of Presenting Complaint:
- Site: Lower back and buttocks.
- Onset: Gradual, began over 14 months ago. No trauma or injury.
- Character: Dull, aching pain with stiffness.
- Radiation: Occasionally radiates to both buttocks.
- Associated Symptoms:
- Morning stiffness lasting >60 minutes.
- Improves with movement, worsens at rest.
- Occasional pain in the heels and Achilles tendons.
- No peripheral joint involvement.
- Timing: Worse in the morning and after prolonged rest (e.g. long drives).
- Exacerbating/Relieving:
- Worse with inactivity.
- Improves with exercise, warm showers and Ibuprofen.
- Severity: Moderate to severe (7/10 at worst), affects daily activities and sleep.
Systemic:
- Fatigue: Yes.
- Fever, weight loss: No.
- Eye: History of red painful eye once (resolved).
- Bowel: Occasional bloating, no blood or diarrhea.
- Skin: No rash present.
- Resp: No dyspnoea or cough.
Past Medical History:
- No chronic illnesses.
Drug History:
- Ibuprofen occasionally.
- No regular medications.
Family History:
- Brother has Crohn’s disease.
- No family history of back problems.
Social History:
- Occupation: Delivery driver.
- Smoking: Smokes 5–10/day.
- Alcohol: Occasionally, 5 units/week.
- Impact: Struggles with long-distance driving.
Ideas, Concerns & Expectations:
- Ideas: “I thought it was a sports injury, but it’s been going on too long.”
- Concerns: “I’m worried it might be something serious.”
- Expectations: “I want to know what’s causing the stiffness and how to fix it.”
MSK Examination of the Back:
LOOK:
- Observe standing posture from side and back (look for loss of lumbar lordosis, kyphosis)
- Look for muscle wasting or asymmetry
- Check gait (can be stiff or antalgic gait)
Findings:
- Flattened curvature of the lower back on lateral inspection
- No muscle wasting noted of the paraspinal muscles
- Nil gait abnormalities
FEEL:
Findings:
- Tenderness noted over the sacroiliac joints and the lumbar portion of the spine
MOVE:
Findings:
- Reduced lumbar flexion noted on Schober’s test (< 5cm increase noted)
- Reduced spinal lateral flexion and extension
- Reduced cervical mobility, especially on cervical flexion
Answer EITHER viva questions OR patient questions
Patient Questions and Answers:
1. “What is ankylosing spondylitis?”
Example answer: “It’s a type of arthritis that causes inflammation mainly in the spine and the joints that connect your lower back to your pelvis. Over time, it can cause stiffness and pain, particularly in the lower back.”
2. “Is there a cure?”
Example answer: “Unfortunately there’s no cure, but it can be managed very effectively with medication, exercise, and lifestyle changes to keep symptoms under control, prevent stiffness and control pain.”
3. “Will it get worse over time?”
Example answer: “If left untreated, it can lead to permanent stiffness or fusion of the spine, but with early diagnosis and proper treatment, we can significantly slow progression.”
4. “Is it genetic?”
Example answer: “There is a strong genetic component in the risk of developing ankylosing spondylitis, with heritability of 97%. There’s a genetic marker linked to ankylosing spondylitis called HLA-B27 that increases the risk. Since your brother has Crohn’s, another HLA-B27-related condition, there is likely to be a genetic link.”
Examiner Questions and Answers:
1. “What are the key clinical features of ankylosing spondylitis?”
- Insidious onset back pain <45 years old
- Morning stiffness >30–60 min
- Improves with exercise, not rest
- Alternating buttock pain
- Peripheral features: enthesitis (Achilles, plantar fascia), anterior uveitis
2. “What investigations would you order?”
- HLA-B27
- Inflammatory markers: ESR, CRP
- FBC (anaemia of chronic disease), U&E, LFTs (baseline for NSAID/DMARD use)
- Pelvic X-ray of SI joints (Radiographically apparent sacroiliitis may take many years to develop, and therefore a normal pelvic x-ray does not exclude the diagnosis)
- X-ray of cervical, thoracic and lumbar spine: Lateral spine films should be requested for all patients to assess disease at baseline and to assess progression.
- MRI of SI joints (Can demonstrate early changes before radiographical signs. Instrumental in allowing clinicians to diagnose AS early
- Consider US to confirm or measure extent of enthesitis
3. “What are the typical imaging findings in AS?”
- X-ray: Bilateral sacroiliitis, sclerosis, erosions, joint space narrowing
- Spine: Syndesmophytes (vertical), bamboo spine (late stage)
- MRI: Bone marrow oedema in SI joints (early inflammatory changes)
Normal
Ankylosing Spondylitis
Case courtesy of Matt Skalski, Radiopaedia.org, rID: 83455
Typical features of ankylosing spondylitis with syndesmophytes, bamboo spine and bony fusion of posterior elements (dagger sign)
Case courtesy of Frank Gaillard, Radiopaedia.org, rID: 7163
Grade IV sacroiliitis, seen most commonly in ankylosing spondylitis.
Case courtesy of Frank Gaillard, Radiopaedia.org, rID: 35986
Lumbar spine film in AS. Fusion of the spinous processes, so called dagger sign on AP projection.
Case courtesy of Frank Gaillard, Radiopaedia.org, rID: 3382
Lateral C-spine film. Shows complete fusion of anterior and posterior elements in ankylosing spondylitis, so called bamboo spine.
Case courtesy of Frank Gaillard, Radiopaedia.org, rID: 2912
4. “How do you manage AS?”
Non-pharmacological management
- Physiotherapy: Postural exercises, spinal mobility, flexibility
- Smoking cessation
- Patient education
- Cardiovascular risk management (Patients with AS have been demonstrated to have an increased risk of death from all causes and cardiovascular causes)
Pharmacological management
- First-line: NSAIDs (e.g., naproxen)
- Adjunctive analgesics e.g., codeine and paracetamol
- Corticosteroid injections
- DMARDs only if concomitant peripheral joint disease (no evidence of efficacy in axial disease)
- Biologics, including anti-TNF and IL-17 inhibitor therapy in patients who do not respond to, or have contraindications to, first-line treatment modalities such as education, exercise, NSAIDs, and corticosteroid injections
Monitor for complications
- Disease complications: osteoporosis, uveitis, restrictive lung disease, cardiovascular disease
- Treatment complications: peptic ulcers, renal impairment, infection and malignancy risk with biologics, DMARD side effects
5. “What are some complications of AS?”
- Spinal fusion
- Osteoporosis
- Anterior uveitis
- Cardiovascular complications (aortitis, conduction defects, stroke, MI)
- Restrictive lung disease (due to chest wall stiffness)
- Neurological involvement (e.g. due to vertebral fracture, dislocation, or the cauda equina syndrome)
Author – Dr Femi Afolabi
Editor – Dr Daniel Arbide
Last updated 18/11/2025
