Abstract
Aim
Bone infection can recur months or years after initially successful treatment. It is difficult to review patients for many years to determine the true incidence of recurrence. This study determined the minimum follow-up period which gives a good indication of the recurrence rate after surgery for chronic osteomyelitis and infected non-union.
Method
We studied five cohorts of patients who had surgery for long bone infection, over a 10 year period. We investigated the efficacy of various antibiotic carriers (PMMA and Collagen; n=185, Calcium Sulphate; n=195, Calcium Sulphate/Hydroxyapatite; n=233) and management of infected non-unions (n=146). Patients were reviewed and Kaplan-Meier Survivorship curves were constructed to show the incidence and timing of recurrence. The microbiology of the initial infection and the recurrent culture was also compared.
Results
759 patients were reviewed between 12 and 131 months after surgery (mean 43.7 months). Infection recurred in 52 cases (6.9%). 34 patients recurred in the first year (65.4%), 14 in the second year (27%), 2 in the third year (3.8%) and 2 in the following 4 years (3.8%). 89% of recurrences after infected non-union occurred early after treatment. Later recurrences, after 3 years, usually followed new injuries or operations and tended to have different organisms from the original infection.
Conclusions
In clinical trials of new methods of treatment of osteomyelitis, a minimum follow-up period of 2 years would reveal over 90% of the recurrences. For infected non-union surgery, one year may be adequate. Late ‘recurrences’ may represent new infections, rather than reactivation of previous infection.
