Spondyloarthropathies — Viva

Long Case Viva Defence

Candidate's opening statement (model answer)

"Mr David Chen is a 28-year-old carpenter who presents with a 14-month history of inflammatory back pain — insidious onset, morning stiffness lasting 2 hours, improvement with exercise but not rest, night pain waking him in the second half of the night, and alternating buttock pain. He also has heel pain on first standing, consistent with enthesitis. He had an episode of acute anterior uveitis in his right eye 3 months ago that resolved with topical treatment. His father has ankylosing spondylitis. He is HLA-B27 positive. [1]

His main problems are:

1. Newly diagnosed ankylosing spondylitis (radiographic axSpA) — confirmed by the modified New York criteria (bilateral grade 2 sacroiliitis on pelvic radiograph plus inflammatory back pain and family history) and the ASAS criteria — with high disease activity (ASDAS-CRP 3.4, BASDAI 6.2) despite trials of two NSAIDs.
2. Reduced spinal mobility — modified Schober 3 cm, occiput-to-wall 4 cm — indicating early structural damage requiring urgent intervention.
3. History of acute anterior uveitis — recurrent risk, sight-threatening, and a key determinant of biologic drug choice.
4. Occupational impact — his job as a carpenter requires physical strength and spinal mobility; his disease is threatening his livelihood. [1]

My management plan follows the ASAS-EULAR 2022 treatment ladder: optimise NSAID therapy at full anti-inflammatory dose, initiate supervised physiotherapy as the non-pharmacological core, and escalate to biologic therapy — I would choose adalimumab, a monoclonal antibody TNF inhibitor, because of his uveitis history. Pre-biologic screening for latent TB, hepatitis B and C, and vaccination update is mandatory. I will counsel him on uveitis recognition and the fracture safety of the stiff spine." [1]

Examiner probing questions and model answers

Q1: "Walk me through why NSAIDs are first-line, and what constitutes an adequate NSAID trial." [1]

"NSAIDs are the first-line pharmacological treatment for axial spondyloarthritis per the ASAS-EULAR 2022 recommendations [4]. This recommendation rests on three pillars. First, NSAIDs provide effective symptomatic control of inflammatory back pain in the majority of patients — the response to a full-dose NSAID is itself one of the ASAS SpA features. Second, the Poddubnyy cohort study from the German Spondyloarthritis Inception Cohort showed that high NSAID intake over 2 years was associated with retarded radiographic spinal progression, particularly in patients with existing syndesmophytes and elevated CRP [1] />. Third, they are inexpensive and widely available.

An adequate NSAID trial means a full anti-inflammatory dose for at least 2 to 4 weeks. For this patient, his ibuprofen was dosed at only 1.2 g/day — that is sub-therapeutic; the anti-inflammatory dose is 2.4 g/day (400 to 800 mg three times daily). His naproxen was at full dose (1 g/day) for 4 weeks. Before concluding NSAID failure, I would trial diclofenac 75 mg twice daily or celecoxib 200 mg twice daily at full anti-inflammatory dose for 4 weeks. However, given his high ASDAS, objective inflammation, and significant functional limitation, I would proceed to biologic therapy — the biologic threshold is ASDAS at least 2.1 or BASDAI at least 4 after at least two NSAID trials, which he meets." [1]

Q2: "Why adalimumab rather than secukinumab for this patient?" [1]

"The choice between a TNF inhibitor and an IL-17 inhibitor for first-line biologic therapy depends on patient-specific factors. For this patient, I choose adalimumab — a monoclonal antibody TNF inhibitor — for three reasons. [1]

First, his history of acute anterior uveitis is the decisive factor. Monoclonal antibody TNFi (adalimumab, infliximab) are proven to reduce uveitis recurrence. Etanercept — the fusion protein TNFi — is specifically ineffective for uveitis and may paradoxically worsen it; I would avoid etanercept in this patient. IL-17 inhibitors like secukinumab have a more modest uveitis-reducing effect than monoclonal TNFi. Given he has already had one episode, preventing recurrence is a priority. [1]

Second, adalimumab is effective for all the domains of his disease — axial symptoms, peripheral arthritis (if it develops), uveitis, and enthesitis. It is well-established with extensive long-term safety data. [1]

Third, adalimumab is self-administered subcutaneously every 2 weeks, which is convenient for a working carpenter. [1]

The dose is 40 mg subcutaneously every 2 weeks. The MEASURE 1 trial established that secukinumab is equally effective for axial symptoms [3], and the Braun infliximab trial [5] established TNFi efficacy — but for this patient, the uveitis history tips the balance to adalimumab."

Q3: "How does the ASAS classification criteria differ from the modified New York criteria, and why does it matter?" [1]

"The modified New York criteria (1984) diagnose established, radiographic ankylosing spondylitis — they require radiographic sacroiliitis (grade 2 bilateral or grade 3 to 4 unilateral) plus one clinical criterion [1]. This patient meets these criteria because he already has grade 2 bilateral sacroiliitis on his pelvic radiograph.

The ASAS classification criteria (2009) were developed to enable earlier diagnosis — before radiographic damage appears [2]. They apply to chronic back pain with onset under 45 and use two arms: the imaging arm (sacroiliitis on radiography OR MRI, plus at least 1 SpA feature) and the clinical arm (HLA-B27 positive plus at least 2 SpA features). MRI can detect active inflammatory sacroiliitis — bone marrow oedema on STIR sequences — years before radiographic change.

Why this matters: the average diagnostic delay in AS is 6 to 8 years, driven by the time it takes for radiographic sacroiliitis to develop. The ASAS criteria and MRI enable diagnosis and treatment of non-radiographic axial SpA early — during the window when inflammation is active and structural damage may still be preventable. This patient was diagnosed relatively early (14 months) because his sacroiliitis was already radiographically visible and he had classical features." [1]

Q4: "What is the role of sulfasalazine or methotrexate in this patient?" [1]

"Conventional synthetic DMARDs have no role in this patient's pure axial disease. The ASAS-EULAR recommendations explicitly state that csDMARDs are not recommended for axial symptoms [4] — the evidence shows they are ineffective for spinal inflammation. This is one of the most commonly tested points in SpA.

csDMARDs are reserved for patients with peripheral arthritis — typically a persistently inflamed knee or hip — where sulfasalazine 2 to 3 g daily can be effective. This patient has no peripheral arthritis currently, so a csDMARD would add toxicity (monitoring, side effects) without benefit for his axial disease. [1]

If he developed co-existing psoriatic arthritis with polyarticular peripheral disease, then methotrexate would be appropriate for the peripheral component — but it would not treat his axial symptoms, which would still need NSAIDs or a biologic." [1]

Q5: "He is 28 and may want children. How does that affect your treatment?" [1]

"Pregnancy planning is an important conversation. The key principles for a man or woman with SpA: [1]

First, NSAIDs are relatively contraindicated in the third trimester of pregnancy (risk of premature closure of the ductus arteriosus). For a female patient, I would plan to switch to paracetamol-based analgesia in the third trimester. [1]

Second, for biologic therapy in pregnancy, certolizumab pegol is preferred because it lacks the Fc portion and does not cross the placenta — it is the biologic of choice in pregnancy. Adalimumab crosses the placenta in the third trimester but is generally considered safe through the second trimester and is the second choice after certolizumab. [1]

Third, IL-17 inhibitors and JAK inhibitors have limited pregnancy safety data — I would avoid them in women planning pregnancy. [1]

For a male patient, the evidence is more limited but TNFi does not appear to affect sperm quality or fetal outcomes adversely. I would reassure him that adalimumab is unlikely to affect his fertility or a partner's pregnancy, but I would document the discussion. The most important principle is that active maternal disease is worse for the pregnancy than well-chosen medications." [1]

Q6: "What counselling would you give about spinal fracture?" [1]

"This is a safety-critical message. The inflammatory process in ankylosing spondylitis, over years, causes the spine to become rigid — syndesmophytes bridge vertebrae, eventually forming the bamboo spine. A rigid spine is also a brittle spine: it behaves like a long bone rather than a flexible column. Even a minor fall — from standing height, off a bicycle, or at work — can cause an unstable three-column fracture, typically at the cervicothoracic or thoracolumbar junction. These fractures have a high rate of neurological deficit and mortality. [1]

I would counsel Mr Chen specifically: if you fall, even if you feel well, you must go to the emergency department and tell them you have ankylosing spondylitis and need a CT scan of your full spine. Do not assume you are fine because the pain seems manageable. I would give him a letter documenting his diagnosis and the need for full spine imaging after trauma. As a carpenter who works at heights, I would discuss occupational safety — appropriate fall protection is essential. [1]

I would also address bone health: the fused spine is osteoporotic. I would arrange a DEXA scan with vertebral fracture assessment, check vitamin D, and consider calcium and vitamin D supplementation and a bisphosphonate if bone density is reduced." [1]

Short Case Discussion

Examination of the spine in ankylosing spondylitis

Examiner instruction: "Examine this patient's spine. He is a 35-year-old man with chronic back pain." [1]

Candidate's model answer: [1]

"I would like to examine this patient's spine systematically — inspection, palpation, movement (spinal and chest), and then a screen for extra-articular manifestations of spondyloarthritis. [1]

Inspection: I am inspecting from behind and from the side. I can see a loss of the normal lumbar lordosis — the lower back is flat. There is increased thoracic kyphosis, and the patient holds the neck slightly forward. This is the classical question-mark posture of advanced ankylosing spondylitis. There is no scoliosis and no surgical scars. [1]

Palpation: I am palpating the spinous processes — they are palpable throughout. I am checking for tenderness over the sacroiliac joints — there is mild discomfort on direct pressure over the sacroiliac joints bilaterally. I am palpating the Achilles tendon insertions and plantar fascia origins — there is tenderness at the left Achilles insertion, consistent with enthesitis. [1]

Spinal movement: I am assessing the range of motion at the cervical, thoracic and lumbar spine. Cervical rotation is reduced to 40 degrees bilaterally (normal above 70 degrees). I am measuring the occiput-to-wall distance — with the patient standing with heels and back against the wall, the occiput is 5 cm from the wall (normal: 0 cm). This confirms reduced cervical and upper thoracic extension. [1]

I am performing the modified Schober test — I mark a point 10 cm above the posterior superior iliac spine line in the midline, and a second point 5 cm below. On maximal forward flexion, the distance between the two marks increases by only 3 cm (normal: above 5 cm expansion). This confirms reduced lumbar flexion. [1]

I am measuring chest expansion at the fourth intercostal space — it is 2 cm (normal: above 2.5 cm, optimally above 5 cm), indicating reduced costovertebral joint mobility. [1]

Synthesis: My findings are reduced spinal mobility in all planes — loss of lumbar lordosis, increased thoracic kyphosis, reduced cervical rotation, occiput-to-wall 5 cm, modified Schober expansion 3 cm, chest expansion 2 cm — with sacroiliac joint tenderness and Achilles enthesitis. These findings are consistent with ankylosing spondylitis. I would like to complete my examination by screening for extra-articular manifestations: examining the eyes for signs of previous uveitis (synechiae), the heart for an aortic regurgitation murmur, the chest for apical fibrosis, the skin for psoriasis, and the nails for psoriatic changes." [1]

Examiner: "What is the modified Schober test and what is the normal value?" [1]

"The modified Schober test measures lumbar flexion. With the patient standing, I identify the dimples of Venus (posterior superior iliac spines) and mark a horizontal line connecting them. I then mark a point 10 cm above this line in the midline and a point 5 cm below it. I ask the patient to bend forward as far as possible while keeping the knees straight. I remeasure the distance between the upper and lower marks. The increase in distance on flexion should be at least 5 cm in a normal adult. An expansion below 5 cm indicates reduced lumbar mobility, consistent with inflammatory spinal disease. This patient's expansion of 3 cm is clearly abnormal. [1]

The original Schober test used a single point 10 cm above the lumbosacral junction (identified by the dimples of Venus) and measured the increase on flexion — below 5 cm was abnormal. The modified version adds a lower mark 5 cm below, which improves reproducibility by anchoring the measurement to the sacrum." [1]

Examiner: "What would you do if this patient presented with a painful red eye?" [1]

"I would treat this as a medical emergency. Acute anterior uveitis (iritis) is the most common extra-articular manifestation of ankylosing spondylitis, occurring in 25 to 40 per cent of patients. It presents as a unilateral, painful, red eye with photophobia, lacrimation and blurred vision. It is not conjunctivitis, which is bilateral, gritty and painless. [1]

My approach: first, explain to the patient that this is likely uveitis related to his spondyloarthritis and that it needs urgent specialist treatment to prevent permanent visual damage. Second, arrange same-day ophthalmology review for slit-lamp examination and initiation of topical corticosteroids (e.g., prednisolone acetate 1 per cent eye drops, frequency guided by severity) and a cycloplegic (e.g., cyclopentolate 1 per cent) to prevent synechiae. Third, ensure the patient has a written plan for future episodes — they are recurrent and each attack risks cumulative damage. [1]

From the rheumatology perspective, I would note that his current or planned biologic therapy should be a monoclonal antibody TNF inhibitor (adalimumab) or an IL-17 inhibitor — both reduce uveitis recurrence. Etanercept is specifically ineffective for uveitis and would be the wrong choice." [1]