Service de rhumatologie,
1 Service de chirurgie pédiatrique,
2 Service de pédiatrie générale, CHU-Tokoin de Lomé and
3 Hôpital Saint-Jean de Dieu d'Afagnan, Togo
Correspondence to:
M. Mijiyawa, BP 80627, Lomé, Togo.
Abstract
Objective. A retrospective study was conducted in order to point out the different kinds of musculoskeletal conditions observed in children attending two Togolese hospitals.
Results. A total of 434 (242 females, 192 males) of the 29 620 children examined (1.5%) were suffering from these conditions. Probable joint and bone infections (187 patients, 43%), limb deformities (106 patients, 24%), osteochondrosis (60 patients, 14%) and vaso-occlusive crisis due to haemoglobinopathies (29 patients, 7%) were the main conditions observed. Osteomyelitis observed in 128 patients affected the humerus (25 patients), radius (10 patients), femur (68 patients), tibia (15 patients), fibula (five patients), and both tibia and fibula (five patients). Probably, infectious arthritis seen in 30 patients affected mainly the hip (11 patients) and the knee (13 patients). In the spine, infection affected the midthoracic and upper lumbar areas. Underdevelopment, sickle cell anaemia and sickle cell haemoglobin C disease were the main risk factors in determining susceptibility to infections. Vaso-occlusive crises were due to sickle cell anaemia (11 patients) and sickle cell haemoglobin C disease (18 patients). Osteochondrosis seen in 60 patients free from haemoglobinopathy involved the spine (Scheuermann's disease, 38 patients) and the hip (LeggCalvéPerthes disease, 22 patients). Limb deformities were observed in the knee (varus and valgus deformities in 64 patients) and the foot (talipes varus equin in 40 patients).
Conclusion. This study's findings, which require further confirmation, suggest some conclusions. Scheuermann's disease can explain in part the degenerative disc conditions observed in African adults. Valgus and varus deformities play an important role in the development of knee osteoarthritis in Black Africa. An African child with joint or bone pain should be investigated for sickle cell anaemia. In the future, improved lifestyle and better health care will be essential to reduce bone and joint infections, and allow refined diagnosis of connective tissue diseases now probably underestimated in African children.
KEY WORDS: Rheumatic diseases, Sickle cell disease, Bone and joint infections, Osteochondroses, Limb deformities, Black Africa.
Musculoskeletal conditions in children were the subject of few studies in Black Africa. Sickle cell anaemia had long focused physicians' attention because of its many complications. Osteonecrosis and bone infections caused by sickle cell anaemia affect particularly the children [15]. The epidemiological profile of chronic rheumatic diseases of African children has to be established. One of the most important studies on juvenile chronic arthritis was that of Bileckot and N'tsiba [6] who reported 25 cases observed in a Congo teaching hospital. The low health coverage of the continent explains the scarcity of data related to connective tissue diseases, malformations and bone tumours in African children. The present paper was designed to establish the different kinds of musculoskeletal conditions in children in two Togolese hospitals.
Patients and methods
This retrospective medical records study was carried out at the rheumatology unit of the Lomé Teaching Hospital and the paediatric unit of Afagnan Hospital.
Afagnan is a district of ~70000 inhabitants, located 80 km from Lomé. Lomé, the capital city of Togo, is located on the west coast of Africa; the population is 800000. Togo is a country of area 56 600 km2, located in West Africa, between 6 and 11°N. Its population is ~4000000 inhabitants. Fifty per cent of Togolese are less than 15 yr old. The population annual growth is 3.1%. Life expectancy is 54 yr. The number of people per physician is 8700, and 1240 per nurse. Mortality is very high, notably among both children and women. The infant mortality rate is 8.6%, whereas the mortality rate among children under 5 yr of age is 13.7%. The maternal mortality rate is ~420/100000 babies born alive. Morbidity is characterized by a strong predominance of infectious as well as parasitic diseases (53.2% in 1992), with malaria being the leading one.
The health sector in Togo is organized like a three-level pyramid. The central level consists of two teaching hospitals located in Lomé. These two centres represent the national level of the care system's expertise. The intermediary or regional level includes five regional hospitals that constitute the care system's second system of referral. Lomé, the capital city, has been promoted to a sixth region. The peripheral or local level consists of 30 district hospitals, five church hospitals (including Afagnan Hospital), socio-medical centres, private health clinics, a secondary hospital located in Lomé, dispensaries and health posts. The district, church and secondary hospitals stand, in principle, for the first level of referral. In practice, this level constitutes the first contact, just like the health facilities of both the central and intermediary levels. A patient could be admitted right away to the teaching hospital without initially consulting any peripheral entity. The Togolese population has at its disposal one health care unit for every 8500 inhabitants. The big discrepancy in allocation of the health facilities results in a distance to be covered that ranges from 3 to 50 km before a patient reaches a peripheral health care unit.
Afagnan Hospital is a church hospital financed by the Fatebenfratelli congregation brothers and has been in operation since 1964. Organizations and associations (Italian International Cooperation of Milan, Swiss Hospital of Porrentruy, Switzerland Earth of People, Bavarian Association in Togo, World Rehabilitation Funds, European Funds of Development, church organizations) contribute to the hospital activities. Afagnan Hospital paediatric unit has a capacity of 106 beds and receives 4900 patients a year. Two thousand of these are hospitalized each year. Chronic infections, parasitic diseases and malnutrition are the main causes of hospitalization in the paediatric unit of Afagnan Hospital.
Lomé Teaching Hospital is the largest health care facility in Togo, with ~170000 out-patients per year. The rheumatology unit came into existence in October 1989. It has a capacity of 28 beds. From October 1989 to December 1996, consulting patients benefited from 9560 consultations in the rheumatology unit; 1166 of them were hospitalized. The bed occupation rate is ~75%. The average duration of hospitalization is >1 month (patients are scarcely seen at the early stage of the disease, there is no care health system in Togo). The main reasons for hospitalization include infections, malignant tumours and lumboradiculalgia of discal origin. The unit, which originally had only one rheumatologist, has now been staffed with two since March 1995. The annual number of consulting patients, which has been ~1000 since 1990, decreased drastically in 1993 and 1994 when 515 and 280 patients were registered, respectively. This fall is due to the socio-political disturbances experienced by the country then.
Patients included in this study were <16 yr of age at the time of their attendance at hospital. They were suffering from musculoskeletal conditions and identified by diagnosis registers established according to the International Diseases Classification [7]. Two groups of patients have been taken into account: those of Lomé Teaching Hospital rheumatology unit seen from 1989 to 1996, and those attending Afagnan Hospital paediatric unit between 1992 and 1996. Each patient's case report contained clinical data (age, sex, place of residence, complaints, vital signs, physical signs), and biological and radiological data. Complete blood count and erythrocyte sedimentation rate were performed in all patients. Joints with clinical evidence of effusion were aspirated to allow cytological and bacteriological studies. Painful joints and bones were examined roentgenographically. In patients with hip involvement, haemoglobin electrophoresis was performed to identify abnormal haemoglobins. Bone or synovial biopsy was carried out in some patients suffering from infection or tumour. Scintigraphy, tomodensitometry and magnetic resonance imaging were not performed in any patient. Patients with juvenile chronic arthritis fulfilled the Cassidy et al. [8] criteria. No patient underwent HLA typing or antinuclear antibody research. Among children with hip involvement, a diagnosis of LeggCalvéPerthes disease had been retained only in the presence of normal haemoglobin.
Results
A total of 434 patients were included in this survey (Table 1). The main diseases observed were osteomyelitis, possible infectious arthritis, limb deformities and osteochondroses (Table 2
).
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Definite or probable arthritis was observed in 30 patients. Joints affected were as follows: hip (11 patients), knee (13 patients), shoulder (five patients) and elbow (one patient). The mean age of patients was 6 yr. Synovial fluid examination identified Escherichia coli in six patients, Salmonella typhi in two patients, Staphylococcus aureus in one patient and Mycobacterium tuberculosis in four patients. In the remaining 17 patients, the aetiology was not established. Clinical and radiological data and synovial fluid leucocyte count provided strong support for the suspicion of bacterial origin.
Spine infection affected 29 children aged from 2 to 15 yr. The mean duration of disease was 4 months. The midthoracic to upper lumbar area was affected in the 29 patients. No patient had cervical spine involvement. Tuberculosis was diagnosed by histology of tissue obtained by surgical biopsy in five patients. In seven patients, microbiological proof of pulmonary tuberculosis was established. Aetiology was undetermined in the remaining 17 patients. Clinical and radiological data allowed a presumptive diagnosis of either tuberculosis (11 cases) or no specific bacterial infection (six cases).
Vaso-occlusive crises were observed in 29 patients carrying haemoglobin SS (18 cases) or haemoglobin SC (11 cases). Handfoot syndrome was observed in three patients. The mean age at crisis onset was 7 yr (8 months14 yr).
The 60 patients affected by osteochrondrosis were free from haemoglobinopathy. LeggCalvéPerthes disease was observed in 22 of them and Schuermann's disease in the 38 others. The disease affected both hips in eight patients. No trauma was mentioned in any patient history. Painful limp was the main complaint. Among the 38 children with Scheuermann's disease, 17 had dorsal kyphosis. Avascular necrosis of the femoral head was observed in four patients carrying haemoglobinopathy (haemoglobin SS: one patient; haemoglobin SC: three patients). Limb deformities observed were as follows: varus deformity of the knee: 34 patients; valgus deformity of the knee: 30 patients; recurvatum deformity of the knee: two patients; talipes varus equin: 40 patients (bilateral involvement in 28 patients).
Histological data obtained after bone or synovial surgical biopsy provided tumour or synovial cyst diagnosis in 15 patients: four patients were suffering from osteosarcoma affecting the radius, femur, tibia and fibula, respectively; five patients were affected by humeral or tibial osteochondroma, one by fibula cyst, two by synovial wrist cyst, one by femoral lymphoma; two patients were affected by Von Recklinghausen's neurofibromatosus found on spinal and both leg bones. Polyarthralgia led to the diagnosis of lymphoid leukaemia in one patient.
The six patients suffering from juvenile chronic arthritis were free from haemoglobinopathy. The mean age of these patients was 11 yr. The mean duration of disease was 18 months. Disease form was polyarticular in three patients, oligoarticular in two and systemic in one. The erythrocyte sedimentation rate ranged from 26 to 128 mm at the first hour.
Discussion
Our study included 434 children suffering from musculoskeletal conditions. The predominant conditions observed included bone and joint infections, osteochondroses, limb deformities, and vaso-occlusive crisis due to haemoglobinopathies.
Flaws resulting from socio-economic data and health care conditions must be taken into account when interpreting the results of this study. The study was carried out in two hospitals. There consequently exists a recruitment bias characterized by the non-representativeness of the population dealt with. Furthermore, the poor access to health centres and the lack of technical equipment are factors that must also be taken into account.
Despite these lapses, this paper is probably the first study of any size on the epidemiology of musculoskeletal conditions in childhood from West Africa. There are few epidemiological data on bone and joint diseases in African children. This rarity is in contrast with demographic characteristics of the African population, with 55% of inhabitants <20 yr of age [9]. Policy makers have long focused their attention on infectious diseases, which are the leading cause of mortality and morbidity. Furthermore, rheumatology is in its infancy and specialists are few.
Children accounted for only 1.7% of the consulting patients of the rheumatology unit. This small proportion is due to the existence, inside the hospital, of a general paediatric unit (9600 consulting patients per year) and of a paediatric surgery unit (700 consulting patients per year). It is in these two units that almost all of the children admitted to the hospital are taken care of.
Our study confirmed the important place of bone and joint infections and haemoglobinopathies SS and SC in Black African children. Infections observed were due to under-development and lack of hygiene. Lack of explorations did not allow establishment of the aetiology in every patient. The delay in the diagnosis was in part due to prior recourse to traditional medicine. Socio-economic development can in the future reduce the relative importance of the infections. In addition, it will allow for better detection and better treatment of some conditions (such as connective tissue diseases), which are probably underestimated now. The importance of vaso-occlusive crisis observed is due to the geographical location of Togo within the sickle cell disease belt, which extends from the 15th parallel north to the 20th parallel south [2, 5]. Vaso-occlusive crises are the most frequent mode of expression of haemoglobinopathies. The clinical picture is usually classic [1, 5]. Differential diagnoses should include rheumatic fever and juvenile chronic arthritis. The high frequency of vaso-occlusive crisis in patients with SS and SC haemoglobinopathies requires haemoglobin electrophoresis in every African child suffering from joint or bone pain.
Scheuermann's disease is a risk factor for degenerative spinal involvement. It can explain, in part, some data observed in adulthood. Recent hospital-based studies carried out in Togo [10], Nigeria [11], Côte d'Ivoire [12] and Congo [13] demonstrated that degenerative spinal disease is not as rare in Black Africa as previously thought [14]. This condition was the leading reason for seeking medical advice among rheumatology clinic patients in both Lomé [15] and Brazzaville [13]. The frequency of LeggCalvéPerthes disease observed was in contrast with the paucity of congenital hip dysplasia in Black Africa, where the practice of carrying babies on the mother's back seems beneficial [16, 17]. Patients with LeggCalvéPerthes disease will probably develop progressive degenerative changes in subsequent years.
Limb deformities were observed in the foot and the knee. Several studies revealed the role of varus and valgus deformities in the high frequency of knee osteoarthritis in Black Africa [1821]. Varus and valgus deformities of the knee were observed in 90% of Togolese women suffering from femorotibial osteoarthritis [20]. Correction of these deformities in childhood would, therefore, be an effective preventive means for knee osteoarthritis in Black Africa.
References