#ortho #tables see also: [[paediatric limp]], [[upper limb non-use]], [[Osteomyelitis]] [RCH bone and joint infection](https://www.rch.org.au/clinicalguide/guideline_index/Bone_and_joint_infection/) and [RCH acutely swollen joint](https://www.rch.org.au/clinicalguide/guideline_index/The_acutely_swollen_joint/) > [!key points] > 1. Osteomyelitis and septic arthritis should be suspected in any child presenting with fever, pain and limited use of the affected limb or joint > 2. Urgent surgical intervention reduces the risk of serious complications in septic arthritis, but should not delay antibiotics > 3. Always consider alternate diagnoses such as trauma, non-accidental injury, inflammatory conditions and malignancy - septic arthritis: usually hip or knee, but could be elsewhere - Kids tend to get septic arthritis in hips and adults tend to get it in their knee - Case recollection: I saw a kid in Launceston with septic arthritis of ankle that had been misdiagnosed as a sprained ankle a few days earlier - osteomylitis: most common femur or tibia, pelvis, and humerus # DDx | |Osteomyelitis|Septic arthritis|Pyogenic myositis|Discitis|Transient synovitis| |---|---|---|---|---|---| |**Fever**|May be absent|Usually present|Usually present|Typically absent or low-grade|Typically absent or low-grade| |**Onset**|Subacute onset of limp, non-weight bearing or refusal to use limb|Acute onset of limp, non-weight bearing or refusal to use limb|Subacute onset. May involve limp|Subacute onset of irritability and back pain. May involve limp or refusal to crawl or walk|Subacute or acute onset of limp. Recent recovery from viral illness| |**Localised features**|Limb pain, may be poorly localised|Hot, swollen, painful, immobile joint|Pain usually well localised. May have abdominal pain (psoas involvement)|May show: refusal to bend forward, loss of lumbar lordosis, percussion tenderness over spine, hip pain, lower limb neurology, ileus (higher lesions)|Weight bearing, with limp| |**Systemic** <br>**features**|With or without systemic illness|Systemic symptoms usually more severe|Systemic symptoms usually more severe|Irritable, with or without systemic illness|Systemically well. <br>Recent viral symptoms| # investigations - bloods incld cultures - X-ray - exclude other causes of pain eg fracture or tumour - usually normal until day 7-10 in osteomylitis - ?USS - identify joint effusion in suspected septic arthritis - highly sensitive, not specific - ?MRI - best test for osteomylitis - sensitive for myositis - CT scan - limited role in bone and joint effusions # Kocher signs of septic arthritis > - temp >38.5 > - inability to bear weight > - WCC > 12 > - ESR >40 4 signs indicates 99.6% probability of septici arthritis; presence of none of them <0.2% probability of septic arthritis # management flowchart ![[Pasted image 20230826015334.png]] # acute joint swelling flowchart ![[Pasted image 20230826021150.png]]