The challenges of diagnosis septic arthritis
-No single test can be relied upon
-Inflamatory markers may be normal or only slightly elevated early in the disease
-The xrays may be normal early in the disaease
-The imaging modalities such as xrays, ultrasound, bone scan or MRI suggest a process of inflammation and effusion but can not diagnose septic arthritis
-The laboratory investigations such as blood counts, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) may help in suggesting that there is an infective process going on but cannot definitely confirm the diagnosis of septic arthritis.
-The only way the joint infection can be conclusively diagnosed is by demonstrating bacteria in
the fluid removed from the joint. However, an organism may only be cultured in approximately 60 percent of cases of true septic arthritis.
-Knee jerk antibiotics may blunt clinical preasentation
– Realizing the limitations of investigations in confirming the diagnosis of septic arthritis, it is imperative that treatment is commenced on the basis of a high index of suspicion. Definitive treatment
should not be withheld for want of confirmatory laboratory tests.