Accepted treatment for acute septic arthritis in children involves drainage of the pus and systematic antibiotics. Review of published studies show that there is a tendency for paediatricians and physicians to drain pus by aspiration and for surgeons to drain the pus by arthrotomy and surgical lavage. There is however no published prospective study comparing the two methods of drainage.

201 consecutive children under 13 (134 boys and 67 girls) presenting to our hospital with acute septic arthritis were entered into a prospective study and randomised to either aspiration of the joint with a 14g needle or arthrotomy and lavage. Both groups had systematic antibiotics for six weeks. All patients were followed up with clinical examination and x-rays at 2, 6, 12, 24 and 52 weeks.

There were 102 patients in the aspiration group and 99 in the lavage group. Both groups were similar in respect to mean age (2 yrs 5m and 2 yrs 10m respectively) and both groups had had symptoms for a mean of 6. 5 days. The commonest joint involved in both groups was the knee, followed by the shoulder, and the commonest organism involved was salmonella, followed by staphylococcus aureus.

Aspiration failed in 9/102 patients who then underwent arthrotomy. Aspirated cases were discharged at a mean of 7. 9 days compared to 9. 8 days in the lavage group. There is no published method of measuring clinical improvement in septic arthritis so we devised the Blantyre septic joint score (BSJS) which measures pain, swelling, range of motion and function. Using the BSJS we found significant difference in scores between the aspirated and the lavage groups at any stage of follow up.

We could not demonstrate any difference in clinical outcome between aspiration and arthrotomy with lavage in the treatment of septic arthritis.