A new classification of osteomyelitis for developing countries.

BACKGROUND The term osteomyelitis (OSM) was first coined by Nelaton in 1844. Waldvogel et al, Cierny-Mader, May et al classifications of OSM from developed countries and Meier et al's from Nigeria have been described. OBJECTIVE This new classification was developed to highlight significant pathology seen in developing countries not covered by existing classifications. DESIGN A prospective study. SETTING University of Ilorin Teaching Hospital, Ilorin, Nigeria. SUBJECTS All OSM patients treated from January 1998 to June 2000. MAIN OUTCOME MEASURES Age, sex, clinical features, radiographs and treatment offered were analysed. Five stages were recognised: stage 0 (potential OSM with bone contamination), stage I (early or acute OSM), stage II (intermediate OSM with subperiosteal abscess), stage III (lateorchronic OSM with sequestrum and subdivided into IIIa 'curable', IIIb 'controllable', IIIc 'complicated'). Stage IV (compound OSM) with joint involvement: IVa, if anatomical and IVb if physiological. Patients' haemoglobin (Hb) status is added to the staging, for example stage II (Hb SS). RESULTS All 271 patients comprising 198 males and 73 females (M: F = 2.7: 1) with age range 2-48 years (mean 29.4 +/- 12.2) were studied. Only 93 patients had Hb genotype done; only 42 had Hb S. The stage O had 184 patients (120 open fractures and 64 bone operations). Stage I had nine patients, stage II 19 patients, stage III 51 patients and stage IV eight. CONCLUSIONS This new staging incorporates pre-emptive OSM seen in developing countries where certain practices, if unchecked lead to OSM. The severity of OSM featuring florid disease not common in the developed world, and for which existing classifications did not accommodate, is included.