Differentiating knee pain with systemic symptoms, knee pain without systemic symptoms, and traumatic knee pain

• The usefulness of differentiating knee pain into these categories to aid diagnosis is based on expert opinion published in guidelines on the assessment and management of knee pain and swelling [University of Michigan Health System, 2005].

Clinical features of Osgood–Schlatter's disease

• These are based on commonly observed symptoms and signs of the condition published in authoritative texts [Davidson et al, 2008].

Investigation of someone with knee pain

• It is expert opinion that Osgood–Schlatter's disease can be diagnosed on the basis of clinical features alone if there are no features of a serious cause for knee pain because [Gholve et al, 2007; Houghton, 2007]:
• Clinical features are sufficiently sensitive and specific to make the diagnosis with a reasonable degree of certainty.
• Routine X-ray examination of the knee lacks sensitivity to diagnose Osgood–Schlatter's disease [Royal College of Radiologists, 2007].
• Investigations to exclude serious causes of knee pain are widely recommended by experts when alerting features for a serious cause are present [Gholve et al, 2007; Houghton, 2007; Royal College of Radiologists, 2007].
• The alerting features of serious causes of knee pain are based on expert opinion published in guidelines on the assessment and management of anterior knee pain [Australian Acute Musculoskeletal Pain Guidelines Group, 2003a].