The histopathological patterns and presentation of chronic osteomyelitis in patients seen at Mulago Hospital

Abstract

INTRODUCTION: Chronic osteomyelitis is a common bone infection. It is a debilitation disease. It is a major cause of outpatient’s attendance, admissions and readmissions to the orthopaedic wards at Mulago Hospital. This disease is difficult to eliminate despite the availability of surgical services and antibiotics. The current practice in diagnosis of chronic osteomyelitis at mulago hospital is based on clinical and radiological features. Other bone infections are hardly diagnosed and the treatment of the disease focuses on pyogenic bone infection by use of ordinary antibiotics. Histopathological examination is rarely done yet it is a valuable tool in detecting other causes of bone infection. Therefore, there is need to determine and document histopathological types of chronic osteomyelitis, so as to assist the clinicians make informed in order to treat the condition more appropriately. STUDY OBJECTIVE: To determine the histopathological patterns and presentation of chronic osteomyelitis in patients seen at mulago hospital. METHODS AND MATERIALS: This was a cross sectional descriptive study of 99 patients who were concestively recruited from the surgical outpatients clinic and from the orthopaedic wards. The patients underwent clinical and radiological evaluation. Then they were operated on and biopsy samples were taken for histopathological examination. The data was recorded on a coded questionnaire and later fed into a computer and analysed using SPSS version 11.5. RESULTS: 99 patients were sampled during the study period. There were five different histopathological conditions identified and these were pyogenic osteomyelitis, tuberculosis osteomyelitis, fungal osteomyelitis, aneurismal bone cyst and osteosarcoma. There were 12 cases(12.1%) of non-pyogenic osteomyelitis. 7 of them had TB, 3 had fungal infection, 1 case of osteosarcoma and 1 of aneurismal bone cyst. Chronic discharging sinus was not a common feature among these patients and there was a statistical correlation between discharging sinuses and pyogenic infection. The tuberculosis osteomyelitis has a relatively longer of sickness. There were 87 cases (87.9%) with histopathological evidence of ordinary bacterial or pyogenic osteomyelitis. The presenting complaints were bone pain, fever, discharging sinuses and pathological fractures. The average duration of the symptoms was 18.1 months. There were 59(59.6%) patients who complained of fever, 72(72.7%) had discharging sinuses, 98(99.0%) had bone pain and 86(86.9) had clinically thickened bone. There were 88(88.9%) single site affection compared to 11(11.1%) with multiple site involvement. Fifty seven(57.6%) patients presented with sequestrum, 31(31.3%) with Brodie’s abscess, 51(51.5%) had radiological evidence of involcrum, and 52(52.5%) with sclerosis. There were 9(9.1%) with joint involvement and 7(7.1%) cases of pathological fracture. Most of the non-pyogenic osteomyelitis patients showed features of less sequestrum, more osteolysis and rarefaction, less involcrum as compared to those with of bacterial chronic osteomyelitis. CONCLUSION: This study has revealed that over 12% of chronic osteomyelitis cases studied had non-pyogenic disease and would have missed correct drug treatment without histopathological examination. Therefore histopathological examination is an important tool in the management of chronic osteomyelitis without which some patients may be misdiagnosed and get wrong treatment.