1. 28th February 2012 Tehseen Ahmed
Monoarthritis
28th February 2012
Tehseen Ahmed

2. Aims and Objectives Aim Objectives
To be able to manage the patient with an acute hot joint
Objectives
By the end of this session you should be able to:
Undertake a relevant history from a patient presenting with an acute hot joint.
Form a differential diagnosis for the patient.
Appropriately further investigate / refer the patient.
Institute initial treatment for your patient.

3. Diagnostic approach
Case scenarios
Diagnostic clues
Investigation
Treatment
Picture quiz

4. Monoarthritis
Inflammation of a single joint
Can be acute or chronic.

5. Acute monoarthritis – Diagnostic approach
History
review of symptoms
previous joint disease or trauma
concurrent illnesses
family history
medication use – e.g. diuretics, anticoagulants
other risk factors
travel, sexual history, diet, tick bites, occupational history, alcohol and intravenous drug use

6. Acute monoarthritis – Diagnostic approach
Examination
Focus on the involved and contralateral joint and surrounding area
General examination to look for other affected joints
Look for systemic manifestations of disease

7. Scenario 1
A 35 year old man presents with a 1 day history of an intensely painful and swollen left knee. He is struggling to weight bear and cannot bend his knee much.
He is otherwise well except for hypertension.

8. Medications Any alcohol? Onset of pain Any previous similar episodes
“ I went to bed fine doctor. When I woke up I could hardly bend my knee”
Any previous similar episodes
“Never in my knee doc. But I had something similar affecting my foot last year. It lasted about two weeks.”
“A&E treated me for a skin infection and gave me some painkillers.”
Medications
“I take a tablet for my blood pressure when I remember …… it don’t half make me pee a lot though doc.”
Any alcohol?
“No more than average like…… 6 pints a night say”

9. On examination

10. Diagnosis?

11. Gout Most common cause of inflammatory arthritis in adults
Usually men >40 years and post-menopausal women
Initially acute monoarthritis
Associated with hyperuricaemia, renal impairment, diuretics, hypertension, hyperlipidaemia, excess alcohol, obesity
Family history in some

12. Gout 50-70% of first attacks affect the big toe.
Other frequently affected joints include the midfoot, ankle, knee, wrist, and elbow.
Shoulders and hips rarely involved.
Can have low grade temperature.
Raised inflammatory markers (can be very high) with neutrophilia.
Majority of patients have further attacks.
Tophi can develop in chronic disease.

13. Scenario 2
A 35 year old American tourist presents with a 2 day history of an intensely painful and swollen left knee. He is struggling to weight bear and cannot bend his knee much.
He reports feeling feverish.

14. Any previous similar episodes
Onset of pain
“ It has swollen up over a few days and it feels hot”
Any previous similar episodes
“First time I have had anything like it”
Medications
“I don’t take anything”
Any alcohol?
“Very little”
Associated symptoms
“I felt feverish last night”
“I noticed a couple of new spots on my body ………. ….like acne”
Anything else?
“I had a one-night stand last week …….. I didn’t use any protection”
“Could it be related?”

17. Diagnosis?

18. Gonococcal arthritis
Gonococcal arthritis is caused by infection with the gram-negative diplococcus neisseria gonorhhoeae.
In the US, gonococcal arthritis is the most common form of septic arthritis.
This is in contrast to Western Europe, where gonococcal arthritis is uncommon.
Gonococcal arthritis is ultimately a consequence of disseminated gonococcal infection.
Haematogenous spread of the mucosal infection occurs in up to 3% of cases.
Time from initial infection to manifestations of disseminated infection ranges from 1 day to 3 months.

19. Synovial fluid cultures can be positive in up to 50% of cases
It manifests as either a bacteraemic infection (arthritis-dermatitis syndrome; 60% of cases) or as a localized septic arthritis (40%).
Arthritis-dermatitis syndrome includes the classic triad of dermatitis, tenosynovitis, and migratory polyarthritis.
Septic arthritis form
Joint symptoms begin within days to weeks of gonococcal infection.
Usually affects one joint.
Most commonly knees, wrists, ankles, elbows.
Synovial fluid cultures can be positive in up to 50% of cases
Cultures from likely sites of initial infection will increase the yield.
Blood culture / Cervix / Rectum / Urethra / Pharynx.
PCR testing of samples can also increase yield if cultures are negative.
Patients with gonococcal arthritis usually require initial IV abx.
Unlike in Staph. aureus septic arthritis, joint destruction is rare.

20. Scenario 3
An 80 year old woman with type 2 diabetes and rheumatoid arthritis presents with a two week history of increasing pain and swelling in her right wrist.
Her rheumatoid is well controlled on medication but her wrist has been a problem and has been injected with steroids recently.
She is feeling feverish and unwell.

21. On examination

22. Diagnosis?

23. Septic arthritis
More common in those with inflammatory arthropathies, joint prostheses, impaired immunity.
Any age affected but more commonly young and elderly.
Systemic symptoms usually present but beware in immunocompromised.
Fever has poor sensitivity and specificity for septic arthritis.
Synovial fluid culture positive in 90%.
More than one joint can be involved in up to 20% of cases.

24. Scenario 4 85 year old woman
RA, OA of the knees, Leg ulcers, Hypertension, PPM
Awaiting Right TKR
2 week history of marked swelling in her left knee
Started suddenly following some physiotherapy
Not systemically unwell.

25. On examination
Large, warm effusion left knee.
Any further info?

28. Haemarthrosis Not always associated with a history of trauma.
Usually significant swelling.
Traumatic causes include cruciate ligament rupture and intra-articular fracture.
Other causes include pigmented villonodular synovitis and bleeding diatheses.

29. In approximately 1/3 of cases of monoarthritis no definitive diagnosis will be identified even after appropriate investigation.

30. Diagnostic clues

31. Sudden onset of pain over seconds to minutes
Trauma
Onset of pain, swelling, tenderness maximal within 12 hours
Crystal arthropathy
Onset of pain over several hours or 1-2 days
Septic arthritis
Monoarthritic presentation of other inflammatory arthropathy

32. Insidious onset of pain & swelling over days-weeks
Low grade/atypical infection, OA, malignancy, granulomatous disease
DM, Cellulitis, Prosthetic joints, RA, IV drug abuse
Septic arthritis
Steroid exposure
Avascular necrosis
Coagulopathy, Use of anticoagulants
Haemarthrosis

34. Other causes of monoarthritis

35. Seronegative spondyloarthropathies

36. Monoarthritic presentation of polyarthritis

37. Pseudogout More elderly age group. Mean age early 70’s.
Acute monoarticular presentation.
In CPPD can also get oligoarticular and occasionally polyarticular disease (can mimic RA).
Often affects the knee, wrist, or shoulder.
Triggers include:
Intercurrent illness
Trauma
Surgery

38. Investigations
JOINT ASPIRATE !!!
Gram stain
M, C & S
Crystal analysis

39. Investigations Blood cultures Bloods – ESR/CRP, FBC, U+E’s, Clotting
X-ray – affected and contralateral joint
Consider: serum urate, CXR, sputum sample, urine culture, skin swabs

40. Treatment – depends on the cause!
Aspirate joint
Analgesia – NSAIDs, Colchicine
Rest / Ice / Elevation
Antibiotics if indicated – 2 weeks IV, 4 weeks oral follow-on
Intra-muscular/Intra-articular/Oral steroids if indicated

41. Learning points
In acute inflammatory monoarthritis, symptoms reaching their maximum within 6-12 hours are highly suggestive of a crystal arthropathy.
Serum uric acid levels do not confirm or exclude gout.
Demonstration of urate crystals in synovial fluid or tophus aspirates is diagnostic of gout.
Beware that gout and sepsis can co-exist.
Repeated culture of synovial fluid, blood and other sources of sepsis may be needed if initial samples are negative but clinical suspicion remains high.
In a young patient with a monoarthritis but no history of trauma, refer to rheumatology NOT orthopaedics.

42. References
Lingling M, Cranney A, Holroyd-Leduc JM. Acute monoarthritis: What is the cause of my patient’s swollen joint? CMAJ January 6; 180(1): 59–65
Margaretten ME, Kohlwes J, Moore D, Bent S. Does this adult patient have septic arthritis? JAMA 2007 Apr 4;297(13):