- Diff Dx:
- reactive transient synovitis (toxic synovitis)
- in the report by Kocher MS et al., the authors sought to distinguish transient synovitis vs sepsis on the basis of lab data and patient history;
- independent clinical predictors between septic arthritis and transient synovitis included history of fever, non-wt-bearing, ESR of at least forty mm/hr, and serum WBC of more than 12,000;
- the predicted probability for septic arthritis were 93% if three of these variables were present and were over 99% if all 4 predictors were present;
- the authors recommend careful observation without aspiration if none of the four independent predictors are present;
- reference:
- Differentiating Between Septic Arthritis and Transient Synovitis of the Hip in Children: An Evidence-Based Clinical Prediction Algorithm.
- Legg-Calve-Perthes disease
- slipped capital femoral epiphysis
- psoas abscess:
- note that these patients will hold the hip in flexion and in internal rotation (which is also seen in septic arthritis of the hip);
- look for atypical features, such as femoral nerve neurapraxia or bladder irritability along with hip pain;
- references:
- Psoas abscess in children. Schwaitzberg SD. J Pediatr Surg. 1985;20:339-342.
- Differentiation of Psoas Muscle Abscess From Septic Arthritis of the Hip in Children. Song J. Clin Orthop Rel Res 2001;391:258-265
- obturator internus pyomyositis:
- patients may demonstrate rectal pain and swelling during an examination;
- in the report by Orlicek SL, et al, the authors describe 4 cases of obturator internus muscle (OIM) abscess in children, including their clinical presentations and treatment;
- common presenting features were fever, limp, and hip pain;
- CT or MRI was diagnostic in all 4 patients, and staph aureus was the causative agent in each;
- all the patients recovered, one after surgical drainage and the other three after antimicrobial therapy alone or with needle aspiration;
- presentation of OIM pyomyositis is similar to that of psoas muscle pyomyositis and other infectious processes of the pelvis and hip;
- most patients can be managed without open surgical drainage, but needle aspirations may be helpful both therapeutically and diagnostically;
- references:
- Case Report. Obturator Internus Pyomyositis.
- Obturator Internus Muscle Abscess in Children.
- acetabular osteomyelitis
- pyogenic sacroiliitis
- vertebral/disc space infections
- proximal femoral osteomyelitis (see above)
- sickle cell anemia;
- juveline rheumatoid arthritis
- neuroblastoma
- uncommon but should be considered in the differential diagnosis;
- abdominal ultrasonography may serve as a screening examination
Primary Pyomyositis of the Pelvis in Children: A Retrospective Review of 8 Cases
Suppurative arthritis of the hip in children.
Long-term follow-up of infantile hip sepsis.
Sequelae and reconstruction after septic arthritis of the hip in infants.
Acute haematogenous osteomyelitis and septic arthritis in childhood: A 10 year review and follow up.
Acute septic arthritis of the hip joint in infancy and childhood.