- general features:
- pediatric bone circulation
- age of patient:
- osteomyelitis in the newborn
- in infants below the ages of 1 year, some metaphyseal vessels may transverse epiphyseal plate and permit spread of infection to epiphysis and adjacent joint;
- this is most common in the hip, and occurs less often in the shoulder, and rarely in the elbow;
- osteomyelitis in the child
- bones of children are enveloped in a tough periosteal sleeve;
- this sleeve is lifted away from the bone by dissecting pus;
- periosteal sleeve is firmly attached to the bone in the region of epiphyseal plate and forms a barrier to prevent spread of infection to the adjacent joint;
- most common organism is staphylococcus aureus;
- streptococcal & haemophilus influenzae bone infections are seen in young children, and sickle cell patients are prone to bone infection by salmonella;
- in older adults and in patients with compromised immune systems, bone infection by gram-negative organisms is common;
- tubercle bacilli and fungi may also cause hematogenous osteomyelitis;
- ref: Microbiological culture methods for pediatric musculoskeletal infection: a guideline for optimal use.
- diff dx:
- leukemia and EOG
- associated conditions:
- septic arthritis
- occurs most often in young children (12 to 18 months) due to the epiphyseal circulation;
- in older children, associatted septic arthritis can occur w/ involvement of the proximal femur (most common), and less often in
the proximal humerus, distal lateral tibia, and the radial head;
- multiple sites of involvement:
- in neonates with hematogenous osteomyelitis, 40% will have multiple sites of involvement;
- Clincial Findings:
- high fever and WBC are variable findings;
- metaphyseal tenderness is often present (joint motion should be unhindered unless septic arthritis is present);
- bone aspiration is performed at site of maximal tenderness using a 16 or 18 gauge spinal needle;
- Radiographic Findings
- radiological features can mimic various benign or malignant bone tumours and non-pyogenic infections;
- Radioisotope Scanning
- useful for identifying multiple sites of involvement (neonates);
- Surgical Debridement:
- some argue that surgical debridement is indicated if pus is aspirated;
- surgical drainage is effected by opening the periosteum and cortical drilling;
- Subacute Haematogenous Osteomyelitis:
- may be an uncommon cause of limp in children;
- dx can be difficult since signs, symptoms, and labs for osteomyelitis are often unremarkable;
- look for sublte extremity swelling and/or subtle loss of range of motion;
- elevated temperature is uncommon;
- radiographs may show a well circumscribed subchondral lesion w/ well defined trabecular margins;
- bone scan is often positive;
- treatment often consists of surgical evacuation both as a therapeutic measure and a diagnostic measure (in order to rule out malignancy);
- in the report by Rascol MN (2001), the author followed 21 children (1990-1998) with primary subacute haematogenous osteomyelitis;
- pain, swelling and a limp had been present for two to 12 weeks with little functional impairment;
- laboratory tests were non-contributory;
- lesions were classified radiologically into metaphyseal, diaphyseal, epiphyseal and vertebral;
- 24 sites involved, with most (20) being in the tibia; 17 lesions were in the diaphysis, 5 in the metaphysis and two in the epiphysis;
- diagnosis was confirmed histologically in all cases;
- staphylococcus aureus was cultured in six patients;
- healing occurred in all patients after treatment with antibiotics for 6 weeks and radiological improvement was seen after three to six months;
- subacute osteomyelitis develops as a result of increased host resistance and decreased bacterial virulence;
- histological confirmation is necessary to avoid a delay in diagnosis;
- Primary subacute haematogenous osteomyelitis of the tarsal bones in children.
- Subacute osteomyelitis presenting as bone tumors.
- Primary subacute haematogenous osteomyelitis in children.
Acute and chronic osteomyelitis in children. Ferguson AB: Clin Orthop 1973;96:51.
Acute osteomyelitis in children: a review of 116 cases.
Pediatric Acute Hematogenous Osteomyelitis
The treatment of chronic hematogenous osteomyelitis.
Acute hematogenous osteomyelitis in children. DR Dirschl. Orthop Rev. Vol 23. 1988. p 61-66.
Primary subacute epiphyseal and metaepiphyseal osteomyelitis in children. diagnosis and treatment guided by MRI.
Haematogenous acute and subacute paediatric osteomyelitis: a systematic review of the literature.