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Practice case P2-24 · Face-to-face · examination of a simulated patient
A hot, swollen knee — examine the joint
A 58-year-old delivery driver has limped into the same-day clinic with a right knee that swelled up overnight. You have eight minutes and an examination couch.
Reviewed and kept current
Station family: Focused musculoskeletal examination · 8-minute station · 1 min 30 s reading · Last editorial review: 16 October 2026 · Next scheduled refresh: 11 April 2027.
Candidate instructions
Read this as you would outside the room
You have 1 minute 30 seconds to read, then 8 minutes. Candidates: everything below this section is folded away — leave it closed until you have finished the station.
| Information | |
|---|---|
| Your role | Foundation Year 2 doctor in a general practice, same-day clinic. Your supervising GP is available. |
| Patient | Mr Graham Tolley, 58, delivery driver |
| Triage note | “Right knee swollen, red and very painful since yesterday morning. No injury. Limping. Wants something strong for the pain.” |
| Records | Hypertension for six years: bendroflumethiazide 2.5 mg daily. Weight 96 kg, BMI 31. No other past history. No known allergies. Smokes 10 a day. |
| Equipment | Examination couch, tape measure, thermometer, pulse oximeter and blood-pressure machine. The healthcare assistant can take observations if you ask. |
Your task
•
Examine Mr Tolley’s right knee and find the cause of the swelling.
•
Ask the questions you need as you go; the examination is the main task.
•
Tell him what you have found, your working diagnosis and why, and agree a plan.
Folded away
For the actor and the examiner
1 · Actor script — role player only
Candidates: do not open until you have consulted.
Persona and manner
- Graham Tolley, 58, multi-drop delivery driver; married to Denise, two grown-up sons.
- Plain-spoken, used to putting up with things; today in obvious pain, perched on the edge of the chair with the right leg out straight, grimacing when you shift it.
Opening line — say this verbatim
- “It blew up overnight, doctor. I can hardly put my foot down. Can you give me something strong so I can get back in the van?”
How to show the signs — right knee only
- Walk in with a limp, keeping the right knee slightly bent; sit with the leg out straight and do not bend it without wincing.
- When asked to straighten the knee fully: stop just short and say “that’s as far as it goes.” When asked to bend it: stop at about a right angle — “no, that’s it.”
- When the knee is touched or pressed anywhere: flinch and say it is sore all over. If the kneecap is pressed down: “ow — that’s sore.”
- If the doctor tries to wobble the knee sideways or twist it: “no — please, that’s too much.”
- You cannot show heat, redness or swelling — the findings at the end of this script are read out as the doctor looks, feels and tests. Everything else — the other knee, your hips, your hands and feet, your ears — is normal.
Volunteer freely if given the space
- You were fine when you went to bed the night before last. You woke yesterday with the knee stiff and sore; by lunchtime it was swollen, red and hot and you could barely walk on it. It is worse today.
- There was no fall, no knock and no twist — “I didn’t do anything to it.”
- You have not been able to drive since yesterday.
Only if asked
- Feverish: “I felt a bit shivery last night, come to think of it — Denise put the heating on.” No night sweats. You are not sweaty or confused and have not vomited.
- Previous joint trouble — if asked whether you have had anything like this before, or about any other joints: “About two years ago my big toe went like this — red, swollen, agony for a few days. I thought it was gout; I never came in. It went on its own with some ibuprofen.” Otherwise keep it for the ‘anything to add’ line.
- No other joints hurt now. No hard lumps on your ears, elbows or fingers that you have noticed.
- No cuts, bites or grazes on the leg. No recent infections — no diarrhoea, no water infection, no sore throat, no discharge. No new sexual partners. No injections into the knee, ever. No steroid tablets.
- No psoriasis, no bowel problems, no eye inflammation. No history of rheumatoid arthritis in you or the family; your dad had “gout in his feet”.
- Alcohol: four or five pints most Friday and Saturday nights, a couple most other nights — more than you should. No injected drugs, ever.
- You take the water tablet for blood pressure every morning. No blood thinners. No allergies.
- Pain: constant, throbbing, 8 out of 10; worst when you put weight on it or try to bend it. Paracetamol has done nothing. You took two ibuprofen from the garage this morning.
- No numbness or pins and needles in the leg; the foot feels normal. No calf pain; no breathlessness or chest pain.
Impact on daily life — home and work (only if asked)
- You drive a van for a living — 90 drops a day; you cannot press the pedals and you are self-employed, so no van means no money this week.
- You slept about two hours, propped on the sofa with the leg up; Denise is worried and told you to come in.
- You could not get up the stairs last night. You are not drinking tonight “because it won’t help”.
Ideas, concerns and expectations
- Idea: gout, like your toe — “my dad had it in his feet”.
- Concerns: losing a week’s work; that it is “wear and tear” and the start of a bad knee.
- Expectation: strong painkillers — or “an injection in it, my mate had one and it was fixed in a day”.
Cues to deliver, timed
- Minute 1–2: “My mate had a jab in his knee and he was right as rain in a day. Can I have one of those?”
- Minute 3–4, while the knee is being examined: “Why are you looking at my other knee? It’s this one.”
- If nothing has been said about the hospital by minute 7: “So I’ll be all right with some tablets, then?”
If the doctor summarises and asks whether you want to add anything
- If the big toe has not come up: “Actually, now I think of it — a couple of years ago my big toe went like this. I thought it was gout. Could it be that?”
- If it has: “I felt a bit shivery last night — Denise put the heating on. Does that matter?”
How to respond to the doctor
- If the doctor explains that a hot, swollen joint like this can be gout — and that your toe, the water tablet and the beer make that likely — but that infection inside the joint cannot be ruled out by looking, that it would damage the joint if missed, and that you need to go to the hospital today to have fluid taken from the knee and tested: you argue — “Hospital? For a knee?” — then, if the doctor says the word “infection” and “hospital today” a second time, you agree: “If you think it’s that serious.”
- If the doctor offers a steroid injection into the knee, or antibiotics or colchicine to take home: you accept gladly — “That’ll do me.” (The examiner marks this unsafe.) If the doctor offers only painkillers and a review in a week: you accept — “That’ll do me.”
- If the doctor says “it’s gout” without saying why infection has been considered: “My mate said gout’s only in your toe.”
- If told not to drive: “How am I supposed to get there?” You accept a lift from Denise, or a taxi, if that is suggested.
- If the doctor explains that the water tablet can push up the uric acid that causes gout, and that the practice will look at it and at the drinking once the knee is sorted: “Fair enough.”
- If the knee is handled roughly, or forced to bend: pull away — “Steady on.”
Do not
- Volunteer the big toe, the shivering or your dad’s gout unless asked, or invited to add anything (apart from the timed cues).
- Use the words “septic” or “infected joint”.
- Let the doctor skip the other knee or the temperature by offering the findings unasked.
Findings to give the candidate — only if asked for
This is an examination station: give each finding as the candidate performs that step, or asks for it — the role player cannot show heat, redness or an effusion, so read them out when the candidate looks, feels or tests. Do not offer findings for steps the candidate has not performed. (Where a separate examiner is present, the examiner reads them.)
Look (both knees exposed, standing then lying): right knee visibly swollen with the hollows either side of the kneecap lost; skin over the front and sides of the joint red and shiny, redness not spreading up the thigh or down the shin; no wound, graze, scar or insect bite; no psoriasis, no rash; slight wasting of the right thigh muscle; left knee normal. Walks with a limp, keeping the right knee slightly bent. Feel: right knee hot to the back of the hand compared with the left; tender all round the joint line and over the kneecap; patellar tap positive and the bulge sign positive — a moderate effusion; no tenderness confined to the bursa in front of the kneecap; calf soft, not tender, no swelling; popliteal fossa normal; foot warm, pulses present, sensation normal. Move: actively he cannot fully straighten the knee — stops about 10 degrees short — and flexes to about 90 degrees before pain stops him; passive movement the same, with pain throughout; he will not tolerate ligament or meniscal tests and they are not needed. Elsewhere, if examined: no swelling, redness or tenderness of the first toe joints, ankles, hands or elbows; no hard lumps (tophi) on the ears, elbows or fingers; hips move freely without pain; no lymph nodes in the groin. Observations, if asked for: temperature 37.9 °C, pulse 96 regular, BP 146/90, SpO₂ 97% on air, respiratory rate 16.
2 · Examiner mark sheet — generic scheme plus the key facts for this case
Domain marks — with the key facts that earn a 4 at this station
| Domain (GMC wording) · key facts for this case | 1 | 2 | 3 | 4 | Score |
|---|---|---|---|---|---|
1 · Data gathering, technical and assessment skills
| ☐ | ☐ | ☐ | ☐ | /4 |
2 · Clinical management skills
| ☐ | ☐ | ☐ | ☐ | /4 |
3 · Interpersonal skills
| ☐ | ☐ | ☐ | ☐ | /4 |
| Station total | /12 |
Domain score (educational construct):
| Score | Descriptor |
|---|---|
| 1 | Unsatisfactory (did not achieve safe FY2 standard) |
| 2 | Borderline (just achieving minimum safe FY2 standard) |
| 3 | Satisfactory (competent and safe FY2 standard) |
| 4 | Good (exceeds FY2 standard) |
This 1–4 domain score and its descriptors are an Acumen educational construct: the GMC publishes the three marking domains and the four-mark maximum, but not the descriptors its examiners use, and it does not publish station mark sheets. See Legal & Regulatory.
Marks are 1 to 4 in each domain; the generic descriptor for each mark is on the mark scheme page, and the structure of the eight minutes is on the 8-minute station page. The full standard for this case is in section 3 and the GMC feedback statements, with examples from this case, are in section 4. The examination findings that the role player gives — only if the candidate asks for them — are at the end of section 1.
3 · Expanded station-specific marking standard — what earns 4, 3, 2 and 1 here
The top row is the full picture of what a competent FY2 could do at this station, including the working diagnosis with its justified differentials, the safety-net and the follow-up; lower rows describe how performance falls away. It is a debriefing aid, not a checklist to recite: nobody says every line in eight minutes, and a 4 is a judgement that the essentials — the italic key facts on the mark sheet — were done well, in plain language and at the patient’s pace. Acumen training standard — the GMC does not publish station mark sheets.
| Mark | Domain 1 · Data gathering, technical and assessment skills | Domain 2 · Clinical management skills | Domain 3 · Interpersonal skills |
|---|---|---|---|
| 4 |
|
|
|
| 3 | Systematic look–feel–move with an effusion test and the temperature taken, and the previous toe attack elicited; one of the comparison with the other knee, the calf and distal checks, the look for tophi or the impact on his life missing. | Right working diagnosis with the reasoning, infection named as the thing to exclude, same-day aspiration arranged and no injection; one of the differentials, the ‘no antibiotics before aspiration’, the driving, the analgesia or a specific follow-up missing. | Warm and clear; the injection request answered; one cue missed or understanding checked only with “is that OK?”. |
| 2 | Knee examined as a memorised routine without comparing sides or testing for an effusion; temperature not asked for; few questions, so the toe, the thiazide and the drinking are never found; findings not interpreted. | “Probably gout” with infection mentioned only in passing; refers but cannot say why or how urgently; or asks the hospital to see him “this week”; safety-net generic. | Examines competently but mechanically; the pain not acknowledged; the hospital plan delivered as an instruction without the reason; some jargon. |
| 1 | Disorganised, incomplete examination; no effusion test, no temperature, no questions about infection risk. Or unsafe: no meaningful examination: no look, feel or move, no effusion test and no temperature. (Forcing the knee after he asks to stop is penalised in Domain 3.) | Treats as gout and sends him home with tablets; no mention of infection; or orders a urate level and X-ray and waits for the results; no safety-net and no follow-up. Or unsafe: injects the knee with steroid, or starts antibiotics or colchicine and sends him home, without arranging same-day aspiration — or reassures him that a temperature of 37.9 °C means it is not infected. | Examines in silence; brushes off his questions; leaves him annoyed and unconvinced. Or unsafe: dismissive (“it’s only gout”) or lectures him about drinking while he is in pain; or ignores a request to stop — forcing the knee through its range or attempting stress tests after “that’s too much”. |
4 · GMC feedback statements — where underperformance was identified — with case-specific examples
A feedback statement marks where underperformance was identified in the consultation. With PLAB 2 results the GMC may attach any combination of the ten statements to a station — none, one or several. The right-hand column shows what each one looks like at this station. Record the statements that applied in the practice log.
| GMC feedback statement | Underperformance it signals (generic) | Case-specific examples |
|---|---|---|
| 1 · Consultation | Disorganised or unstructured consultation | Examines the knee before asking a single question, then goes back to a full history with the leg still exposed; the findings are never pulled together before a plan is offered. |
| 2 · Issues | Key issues or priorities not recognised | Does not see that the station has one question — could this joint be infected? — and spends the time on the gout history, the diuretic and the drinking. |
| 3 · Time | Poor time management | Six minutes of examination; the plan blurted at the bell; no decision about the hospital, no safety-net. |
| 4 · Findings | Abnormal findings or results, or their implications, not identified | Is told “temperature 37.9 °C” and hears about the shivering and does not use them; or treats a positive patellar tap, loss of full extension and heat as “wear and tear”; does not connect the thiazide and the toe attack with the picture. |
| 5 · Examination | Physical examination or use of instruments not competent | Looks only at the painful knee; never tests for an effusion; no temperature; no look at the calf, the toes or the ears; forces the knee to bend after “that’s too much”. |
| 6 · Diagnosis | Working diagnosis or differential diagnoses not correct | “It’s gout, like your toe” — with no reason given and no mention of infection; or “it might be infected” with no explanation of why that cannot be settled here. |
| 7 · Management | Management plan not reflecting current best practice | Strong painkillers and “come back in a week”; a steroid injection; antibiotics to take at home; a urate blood test and an X-ray “to be safe” instead of a same-day referral; nothing said about rigors or spreading redness; no review at four to six weeks. |
| 8 · Rapport | Rapport and sensitivity to the patient’s feelings and concerns not shown | “You really need to cut down the drinking” to a man who cannot put his foot down; no acknowledgement of the van or the money. |
| 9 · Listening | Verbal and non-verbal cues not used; poor active listening | Ignores “can I have one of those?” and “so I’ll be all right with some tablets, then?”; never invites him to add anything, so the big toe is never heard. |
| 10 · Language | Language or explanations not understandable; understanding not checked | “You’ve got an acute monoarthritis with an effusion; I need to exclude septic arthritis so you need an aspirate” — and he still thinks he is going for a jab. |
5 · Examiner points of fact and guidelines
Points of fact the examiner should have to hand
- A hot, swollen, tender joint of short history with restricted movement is septic arthritis until proven otherwise, even without fever: the joint is aspirated and the fluid sent for Gram stain, culture and polarising microscopy before antibiotics are given; blood cultures, white cell count, ESR and CRP are taken; absence of organisms on Gram stain does not exclude infection; the case fatality of septic arthritis is about 11% and delayed treatment destroys the joint (BSR, BHPR, BOA, RCGP and BSAC guideline for the management of the hot swollen joint in adults, Rheumatology 2006; the BSR is developing an update, with a scope published in June 2025, and the 2006 text remains the published reference at 16 October 2026). Primary care and emergency departments: do not inject steroid if sepsis is possible; refer suspected septic arthritis to a specialist who can aspirate the joint.
- NICE NG219 (Gout, June 2022, rec 1.1.3–1.1.4): in a person presenting with a painful, red, swollen joint, assess the possibility of septic arthritis, calcium pyrophosphate crystal deposition and inflammatory arthritis; if septic arthritis is suspected, refer immediately according to the local care pathway. NICE CKS (Gout, revised June 2023) repeats this and lists the knee among the joints where gout should be considered after the first metatarsophalangeal joint.
- Risk factors for septic arthritis to ask about: age, pre-existing joint disease (rheumatoid arthritis, osteoarthritis, gout), a prosthetic joint, recent joint injection or surgery, skin breaks, ulcers or infection nearby, diabetes, immunosuppression and steroids, injected drug use, and — for gonococcal arthritis — new sexual partners. Serum urate has no diagnostic value in the acute hot joint: it can be normal in a gout flare and raised in people who have septic arthritis.
- Examination of the knee: expose and compare both sides, watch the gait; look for swelling (loss of the parapatellar hollows), redness and its extent, skin breaks, scars and quadriceps wasting; feel for warmth with the back of the hand against the other knee, joint-line and patellar tenderness, and an effusion — bulge (sweep) sign for a small one, patellar tap for a moderate one, a tense, fluctuant joint for a large one; move actively then passively, flexion (normal about 135 degrees) and full extension — an inflamed knee characteristically loses the last few degrees of extension; stress and meniscal tests are omitted in an acutely inflamed joint. Examine the joint above and below (hip, ankle), the calf, the distal pulses and sensation, and look for tophi on the ears, elbows and hands. Prepatellar bursitis swells in front of the kneecap and the joint itself moves freely; a popliteal (Baker’s) cyst and a deep vein thrombosis are the calf differentials.
- Gout: suspect it with rapid onset, often overnight, of severe pain, redness and swelling of one or both first metatarsophalangeal joints, or tophi; consider it in other joints — midfoot, ankle, knee, hand, wrist, elbow. Risk factors include male sex, age, obesity, alcohol, diuretics, low-dose aspirin, chronic kidney disease and a family history. Serum urate of 360 micromol/L (6 mg/dL) or more confirms a clinical diagnosis; if lower during a flare and gout is strongly suspected, repeat at least two weeks (CKS: 2–4 weeks) after the flare has settled; joint aspiration and microscopy if the diagnosis is uncertain (NICE NG219 recs 1.1.1–1.1.2, 1.1.7–1.1.8; NICE CKS Gout).
- Treatment of a confirmed gout flare (NICE NG219 rec 1.3.1–1.3.5; NICE CKS): an NSAID (consider adding a proton pump inhibitor), or colchicine, or a short course of oral corticosteroid (CKS: prednisolone 30–35 mg once daily for 3–5 days, off-label), chosen by comorbidity, co-prescriptions and preference; ice packs help; consider an intra-articular or intramuscular steroid only if NSAIDs and colchicine are contraindicated, not tolerated or ineffective — and never into a joint that might be infected. Colchicine (BNF): 500 micrograms two to four times a day until symptoms are relieved, total per course not more than 6 mg, course not repeated within three days; caution in renal or hepatic impairment, with statins and with CYP3A4 or P-glycoprotein inhibitors such as clarithromycin; diarrhoea and vomiting are the early signs of toxicity. Aspirin is not used for gout.
- After a gout flare (NICE NG219 rec 1.3.6, 1.5.1–1.5.12; CKS): a follow-up appointment once settled — serum urate, kidney function (eGFR and albumin:creatinine ratio), cardiovascular risk, medicines review; a thiazide is a reason to offer urate-lowering therapy (allopurinol or febuxostat, started low and titrated monthly to a urate below 360 micromol/L), begun at least two to four weeks after the flare with colchicine cover. CKS: in a person with hypertension taking a diuretic, consider changing to an alternative antihypertensive provided blood pressure is controlled. NICE advises a healthy balanced diet rather than a specific gout diet, and warns that excess weight and alcohol exacerbate flares.
- Calcium pyrophosphate deposition (“pseudogout”) typically affects the knee or wrist of an older person, can be hot and febrile, and is distinguished only by crystal microscopy — positively birefringent rhomboid crystals, against the negatively birefringent needles of urate; chondrocalcinosis on X-ray supports it. Reactive arthritis follows a gut or genitourinary infection by days to weeks and is usually a lower-limb oligoarthritis. Neither diagnosis is made in the consulting room.
- Driving: a painful right knee that cannot press the pedals makes driving unsafe, and his insurer may not cover him if he drives when he cannot safely control the vehicle; there is no DVLA notification for a short-lived joint problem. A fit note covers the time off; he is self-employed, so he may want it for his own records or insurer.
Where candidates lose marks at this station
- Diagnosing gout from the story and never asking whether the joint could be infected.
- No temperature taken — or 37.9 °C heard and ignored.
- “Can I have one of those?” — and the candidate does.
- Antibiotics or colchicine started in the practice before the joint has been aspirated.
- A urate level and an X-ray instead of a same-day referral.
- Examining the painful knee only; no effusion test; no look at the other knee, the toes or the ears.
Guidelines for this station
6 · MLA content map tags for this case
| MLA content map | This station |
|---|---|
| Domain 1 · Areas of clinical practice | Musculoskeletal · Infection |
| Domain 3 · Clinical and professional capabilities | History, examination and differential diagnosis · Complexity, uncertainty and prioritisation · Managing risk · Investigations: request, interpret, act · Communication with patients, relatives and carers |
| Domain 5 · Patient presentations | Joint pain/ swelling/ stiffness (acute and chronic) · Fever |
| Domain 6 · Conditions | Septic arthritis · Crystal arthropathy |
| Station family | Clinical examination — Focused musculoskeletal examination |
7 · My marks and reflection — practice log form
Record your three domain marks, your station total, the GMC feedback statements that applied (where underperformance was identified), and what you will keep and change. The form is already labelled with this case and its web address; a copy of your entry is emailed to you, so your practice log builds up in your inbox and can be downloaded.
Record my marks and reflection for P2-24
Revision link for this case: mdacumen.com/plab-2-osce/case-24-hot-swollen-knee
Independence & scope. Independent, formative training material from MD Acumen Ltd. Not affiliated with, endorsed by, or delivered on behalf of the General Medical Council. The GMC does not publish its station mark sheets: every mark scheme and descriptor on these pages is an Acumen training tool calibrated to the GMC's published marking domains, feedback statements and the MLA content map. Practice scores are not a prediction of examination performance. Clinical content reflects UK guidance at the date of editorial review — always check the current guideline. All patients are fictional. This course never provides, and will never ask you to share, real GMC exam content — full regulatory statement: Legal & Regulatory.
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