Jointed

A 22 year old man presents with pain and swelling of his right knee for 2 weeks. The pain worsens with weight bearing. There is no history of trauma.

He was prescribed ciprofloxacin for an urinary tract infection around 3 weeks ago. His medical history is otherwise unremarkable.

He is sexually active,

Select Relevant Investigations
X-Ray R/s Knee Joint

Performed

Anteroposterior, lateral and axial patellar images are obtained. These are only significant for mild soft tissue swelling and a moderate effusion.
R/s Knee Joint Aspiration

Performed

Appearance: turbid
WBC: 7,000/mm3 (< 200)
PMN: 80% (< 20%)
Glucose: 70 mg/dl (normal: within 10 mg/dl of serum glucose)
Protein: 4 g/dl (1 - 3)
Gram stain: no organisms
Crystals: not seen
Random plasma glucose: 80 mg/dl
Urethral swab + Chlamydial NAAT

Performed

Positive for Chlamydia.
HLA-B27 assay

Performed

The HLA-B27 assay is negative.

Select Relevant Management
Immobilize joint
Antibiotics
Sulfasalazine
NSAIDs