Our study took place in the Rheumatology Department of Bè Hospital, a level two hospital in the Togolese health pyramid, located in Lomé. It was a cross-sectional study with retrospective collection of medical records.

The study ran from 1 January 2015 to 31 December 2020.

All patients aged 18 and over seen in consultation during the study period for low back pain with no other associated spinal or peripheral joint disorders and who had undergone at least one imaging examination were included. Files that could not be used were excluded.

The data was collected using a survey form containing socio-demographic data (age, sex, profession, marital status), clinical data (pain characteristics, medical history, physical signs), paraclinical data (imaging, biology, histology) and aetiological aspects.

Common low back pain: Low back pain is considered common (or non-specific) in the absence of warning signs (red flags), which must be systematically sought out and which may lead the doctor to suspect a serious extra-spinal pathology or an urgent spinal pathology (infection, tumour, chronic inflammatory rheumatism, etc.). “False low back pain”, i.e., referred pain of visceral origin, must also be ruled out. Common low back pain is initially considered to be mechanical in origin, with degenerative damage to the discs and posterior interapophyseal joints, static disorders (spondylolisthesis, scoliosis, etc.) or no major abnormalities found in the assessment, particularly in imaging.

Housewife: a non-working woman who is responsible for running the household.

Artisan: a person who practises a mechanical or manual craft, following the rules of an established art.

Worker: a person who, in return for payment, carries out work, usually manual, for an employer in the building, industrial or agricultural sectors.

Office worker: an employee working in an office, without any command or decision-making function, to carry out tasks of an administrative nature.

The data was entered using Epidata 3.1 software. The database was analysed using Microsoft Excel 2019 and R 4.0.4 in the RStudio 1.4 environment. Quantitative variables were described as means ± standard deviation. Qualitative variables were described in terms of numbers and percentages, and compared using chi2 or Fisher tests. The significance threshold was set at a p-value strictly less than 0.05.

This study received ethical approval from the Ethics Committee of the Hôpital de Bè. Patient consent was not obtained due to the retrospective nature of the recruitment. Patient confidentiality was maintained and the study complied with the World Medical Association’s Declaration of Helsinki.

The mean age of the patients was 47.8 ± 13.9 years (extremes 18 and 88 years). Females predominated, with an M/F sex ratio of 0.54. The most common occupations were shopkeepers (37.6%), craftsmen (13.4%) and manual workers (7.3%) (Table 1).

Table 1. Distribution of patients by socio-demographic data.

The mean duration of low back pain was 14.3 ± 31.6 months (extremes three days and 420 months). Low back pain was mechanical in 985 patients (81.5%), inflammatory in 206 (17.1%) and mixed in 17 (1.4%). It was impulsive in 430 patients (35.6%). Radiculalgia was present in 908 patients (75.2%). It was unilateral in 490 patients (54%), L5 in 508 patients (55.9%) and S1 in 160 patients (17.6%). Low back pain evolved in a sawtooth pattern in 984 patients (81.5%). The exacerbation factors were prolonged standing and/or walking (50.6%), carrying heavy loads (15.3%) and changes in position (11.5%). Functional impairment was present in 628 patients (52.0%). In 37.3% of cases, this was a limitation in walking perimeter, in 30.9% a reduction in activities of daily living, and in 1.9% functional impotence. The most common comorbidities were arterial hypertension (70%), overweight and obesity (63.6%), and diabetes (14.1%). Five hundred and fifty-two patients (45.7%) had a history of low back pain, and eight patients (0.6%) had a history of low back trauma.

Eight patients (0.7%) had a fever. Weight loss was present in 169 patients (14%).

The spinal syndrome consisted of pain on palpation of the spinous processes in 890 patients (73.7%), stiffness in 878 patients (72.7%), static problems in 212 patients (17.5%), and an analgesic attitude in 199 patients (16.5%). Twelve patients (1%) had a gibbosity.

Neurologically, 561 patients (46.4%) had a Lasègue sign, 350 (28.9%) a bell sign and 73 (6%) a Léri sign. Motor deficits were noted in 37 patients (3.9%), including three cases of paralysing lomboradiculalgia and two cases of cauda equina syndrome.

All patients had a standard X-ray. An abnormality was found in 1107 patients (91.6%). Degenerative disc disease was noted in 97.4% of cases. Five patients (0.5%) had vertebral compression, including two of traumatic origin, two of undetermined origin and one of tumour origin (Table 2). Twenty-five patients (2.1%) had undergone a CT scan and five patients (0.4%) a magnetic resonance imaging (MRI) scan.

Table 2. Distribution of patients according to the results of standard lumbar spine radiography.

Degenerative pathology was the most common, accounting for 99.6% of cases, followed by infectious pathology (0.2%) and tumour pathology (0.1%) (Table 3). There was a statistically significant relationship between age and diagnosis: common low back pain was observed in younger subjects, and common lumbaradiculalgia and narrowed lumbar canal in older subjects (p < 0.000). The aetiologies were not influenced by body mass index, particularly obesity.

Table 3. Distribution of patients according to the diagnosis.

This five-year retrospective cross-sectional study aimed to determine the epidemiological, clinical and paraclinical characteristics of low back pain in Togo. The hospital incidence of low back pain was 29.4%. The mean age of patients was 47.8 ± 15 years. Women accounted for 64.9% (sex ratio M/F: 0.54). The mean duration of the disease was 14.3 ± 31.4 months. Low back pain was mechanical in 81.5% of cases, and radiated to the lower limbs in 75.2% of patients. Radiation was unilateral in 54% of patients, and followed the L5 pathway in 55%. Degenerative pathology accounted for 99.6% of cases. Clinical form (common low back pain, common lumbaradiculalgia, narrowed lumbar canal) was influenced by age (p ≤ 0.000) but not by body mass index.

If these results are to be interpreted rigorously, the shortcomings associated with recruitment bias must be taken into account. The cross-sectional nature of the study meant that it was not possible to describe or assess the risk factors for low back pain previously described in African populations, such as personal or family history of low back pain, smoking, alcoholism, manual work, long walks, psychological factors and marital status [11]. In addition, this was a single-centre hospital study which only included patients attending the rheumatology department. The inclusion criterion requiring at least one imaging exam may introduce selection bias by potentially over-representing patients with more severe or persistent symptoms. However, this study shows that low back pain is not confined to university hospitals, as in the previous study carried out in Togo, but appears to be common in all health facilities, which would indicate that it is ubiquitous. The retrospective nature of the recruitment, with numerous selection biases and missing data, adds to the previous limitation, making it impossible to generalise our results. The low standard of living of the population (guaranteed minimum wage = USD 62.17 at the time of the study) explains the difficulty of carrying out the CT and MRI scans recommended in certain diagnostic algorithms. Imaging consisted essentially of standard radiography. These limitations do not alter the epidemiological interest of our work.

The first large-scale study on low back pain in Togo was conducted in a level one university hospital [13]. The hospital frequency of low back pain was 35.3%. Mean age at onset was 42 years, and mean duration of low back pain was three years. Females were represented 57.7%. Degenerative spinal disease was 95.3%. The present study, conducted in a level two hospital, shows that a quarter of a century later, low back pain remains a public health problem. Indeed, it affects three out of ten patients consulting a rheumatologist. High hospitalisation rates have also been found in Ivory Cost (41.6%) [10], and a point prevalence of between 32% and 39% has been found in systematic reviews conducted in Africa [11][12]. Low back pain is therefore a real health problem among non-communicable diseases in Africa. Disseminating these results will help guide policy makers in implementing specific measures. Preventive and curative measures for the management of people with low back pain should be introduced. This would involve training healthcare professionals in the management of low back pain and its specificities, as well as training more rheumatologists.

The average age of patients in our study was 47.8 years, with extremes of 18 and 88 years. This makes low back pain a problem for active individuals in their prime. However, young adults are not spared. Vujcic et al. [14], in a study of Serbian medical students, found a prevalence of 59.5% over the previous twelve months, with an average age of 22.5 years.

In our study, there was a clear predominance of women (64.9%). This predominance was found by Doualla et al. in Cameroon (70.1%) [15], and in Ivory Coast by Traoré et al. (63.8%) [10]. This female predominance of low back pain is also found in the literature [16]. In our context, it could be explained by the arduous nature of domestic work, which very often puts strain on the back and is usually performed by women. Other explanatory factors could be hormonal (menstruation, menopause) and psychosocial (women are more likely to report pain, whereas African men tend to under-report their health problems because they perceive them as an attack on their masculinity) [17].

The mean duration of evolution was 14.3 months. This result is similar to that observed by Kakpovi et al. in 2017, who found an average duration of 10.3 months [18]. This long waiting time before consultation could be explained on the one hand by the low income of the population and the absence of effective universal health cover, the trivialisation of symptoms, self-medication and the intervention, in our context, of several actors, notably traditional healers and the religious community, before the specialist’s opinion. The low number of rheumatologists in Lomé and the lack of knowledge on this specialty among carers and patients could also play a role.

Obesity is recognised as a risk factor for common low back pain. This could be explained by mechanical overload, low-grade systemic inflammation and reduced physical activity [19]. Our study did not find this link, nor did other authors [20][21]. These discrepancies qualify the link between low back pain and obesity. Obesity may be a predisposing factor, but other variables (genetics, posture, lifestyle) may also play a role. Differences in study design must also be taken into account.

Low back pain was mechanical in 81.5% of cases, and radiated to the lower limbs in three-quarters of cases. Radiation followed the L5 path in 55.9% of cases. This data is similar to that of Diomandé et al. in the Ivory Coast [22] and Doualla-Bija in Cameroon [23]. The predominance of L5 sciatica is explained by the frequent location of disc herniations at the L4-L5 and L5-S1 intervertebral discs, and by the particular anatomy of the spinal canal and foramen at this level [24]. In our study, functional impairment affected more than half of the patients at the time of diagnosis. It was rarely due to a neurological deficit, which would justify the delay in diagnosis. Sensory impairment was predominant.

In terms of aetiology, degenerative pathology accounted for 99.6% of cases. This result is consistent with that of Mijiyawa et al. in 2000 [13] in Togo, who found 95.3%. Amongst the mechanical causes, disc degeneration dominated (97.4%). This predominance has also been described by Bogduck [25] with a frequency of between 40% and 50%, from the age of 40. Pathologies of the posterior arch ranked second, with spondylolisthesis (5.4%). Tagbor et al., in a study in Lomé, found that spondylolisthesis affected women in preference (88.1%), and manifested itself as lumboradiculalgia in 92.4% of cases [26].

Symptomatic low back pain in our study appeared to be exceptional (0.4%), although cross-sectional imaging was rarely performed. This result is lower than those of Mijiyawa et al. in Togo, Traoré et al. in the Ivory Coast and Zomalheto et al. in Benin, who found 3.8% [13], 9.32% [10] and 32.3% [9] respectively. These different studies were carried out in University Hospitals, where patients are usually in a more serious condition.

Modifiable risk factors are poor back hygiene, bad posture, and manual labor.