Our prospective and retrospective descriptive study was carried out in the neurosurgery department of the CHU Mother-child “the Luxembourg” in Bamako over a period of 9 years from 2010 to 2018.

The study involved a series of 42 patients who performed imaging examinations and operated on for spondylolisthesis in the Neurosurgery Department of the Mother and Child Hospital Center “Luxembourg” during the study period.

All patients who presented with spondylolisthesis on one of the radiology examinations of the Luxembourg imaging department and operated on in the Neurosurgery department whose clinical and radiological records were usable were included.

All patients with unusable files not explored radiologically or not operated.

The data was collected from a pre-established survey sheet, including epidemiological, clinical and radiological data.

The type of spondylolisthesis was specified by the presence of degenerative lesions (degenerative spondylolisthesis or SLD) or by the presence of isthmic lysis of traumatic origin (spondylolisthesis by isthmic lysis or SLI).

The qualitative variables were described by means and the quantitative variables by numbers and percentages.

We used SPSS version 21.0 software for data analysis and Microsoft Office 2016 Pack for text and table entry.

The collection of data was carried out with respect for the anonymity of the patients and the confidentiality of their information; the surname and first name of the patients were coded in order to preserve anonymity.

We collected 42 patients operated for spondylolisthesis out of 145 patients operated on the lumbar spine during the study period, i.e., 29%. The prevalence of this pathology in the world would vary between 4% and 9%, according to Hu SS [3]. Its frequency is poorly evaluated in our country because of the multiplicity of the course and the management of patients.

The average age of our patients was 51 years old. Koné P. [5] found an average age equal to 48.53 years. This relatively early age can be explained by the harsh living and (country) working conditions in our towns and villages.

Spondylolisthesis was more common in women in our study, as in the study by Sanoussi [6] (55%) in 2006, but not blatantly. Our result agreed with the study by Koné P. [5] who found (66.7%). This female predominance could be

explained by the harshness of household chores involving women on the one hand, and also by the mechanical constraints of the work which is always done in bending in our countries (fieldwork, laundry, cooking activities, sweeping, drawing water, carrying loads on the back) increasing the pressure on the discs and on the posterior elements (isthmuses, joints) [7]. Moreover, in addition to women, our sample also includes other populations at risk; in particular, the military, sportsmen and forced laborers who were male just like in the study of [7] which found 55.84% of forced workers.

Our patients mainly came from Bamako and its surroundings in 83.4% of cases, which can be explained by geographical proximity and easier access to health structures and to radiological and diagnostic examinations.

The duration of evolution of the symptomatology was more than 2 years. This result is compatible with that of Lamini [8] who found 2.3 years. This could be explained by cultural considerations (resisting pain, mystical considerations), reluctance to intervene for fear of complications, difficulties in accessing care, or else a lack of knowledge of the real nature of the pathology. This has the effect of lengthening the therapeutic course.

Radiculalgia and neurogenic claudication, which reflect a neurological conflict, were at the forefront in 88% of our patients. The study by Abdoulatif A., [7] found 89.63% respectively. The frequency of these signs could thus motivate the consultation and the performance of radiological examinations with the aim of possibly surgical management, contrary to the data of Koné P. [5], who found a frequency of 48.8% and in which the treatment was conservative.

CT and myeloscanner were the most performed first-line examinations in our study with 57.1% and 47.6% respectively.

This could be explained by the clinical symptomatology already evolved at the time of the consultation, making conventional radiography useless because it requires at least an analysis of the bone content and structures. Moreover, sometimes patients have already taken conventional radiographs and the next step, given the symptoms, is therefore CT.

Myeloscanner, an invasive examination, was also performed by some of our patients.

These examinations were sometimes associated in some patients with myelography, coupled with dynamic X-rays in 3 cases, allowing a very good dynamic analysis of the content.

Our results were compatible with those found by Abdelli [9] 42.1% CT, 53.33% in Ranib [10]. CT therefore remains the best compromise between cost, accessibility, exploration of the container and content for the operative planning, but remains a source of irradiation. Our results were different from those of Koné P. [5] where conventional X-ray represented 91.1% of radiological examinations performed in Rheumatology. These were patients treated in rheumatology in a conservative manner that did not necessarily require exploration of the contents, hence the interest in cross-sectional imaging (CT and MRI) [11] for operative planning.

MRI was performed one patient in our series, as it is difficult to access due to cost and lack of available devices. And yet she has undeniable advantages in the exploration of spinal content, disc quality, soft tissue and stenosis [12].

Spondylolisthesis by isthmic lysis was the most common in our study with 57.1% of cases, 66.6% of which were women. These data were compared to the results of Abdoulatif who found 53.89% spondylolisthesis by isthmic lysis, 60% in the study by Ranib M. [10].

The mean age difference between isthmic lysis spondylolisthesis (48.66 years) and degenerative spondylolisthesis (54.56%) in our study was also found by other authors Abdoulatif A. [7], but with an age of lower benefit for spondylolisthesis by isthmic lysis (31 years for Abdoulatif A. [7]) and comparable ages for degenerative spondylolisthesis. However, spondylolisthesis due to isthmic lysis remains the prerogative of young subjects with an average age varying between 25 and 30 years [13].

The most affected lesion level was L4 - L5 with 75% for spondylolisthesis by isthmic lysis and degenerative spondylolisthesis, which was also found by Koné P. [5] with 66.6% of cases. We found 37.1% lysis of L4 and 34.5% lysis of L5. The same findings were made by Koné P. [5] Who found 48.9% and 37.8% of cases respectively. Other authors, such as Abdoulatif [7], instead found L5 lysis in 60% of cases. These results were different from those found in our study, because their sample was smaller and the study was prospective. The floor lysed here is very heavily used during bending movements for household chores and field work in our countries.

The multiple isthmic lysis found in 4 patients in our study could be related to familial, dysplastic or constitutional factors as reported by Wiltse [2].

The most common grade of listhesis was Meyerding grade 1 with 83% of cases. This frequency could be explained by an under-evaluation of the grade because the examinations carried out (CT) are not covered. The presence of foraminal stenosis related to Gill's nodules will lead to glaring symptoms, despite the low relative grade. In comparison, Newman [13] found 51%. It should be noted that our study concerned symptomatic or deficient spondylolisthesis with already a clinical indication for surgery, also found by Iba Ba [4]. Nevertheless, all the patients followed a first-line conservative treatment (analgesics, NSAIDs, lombostat, rehabilitation). This was also found in the study by Iba Ba [4].

A herniated disc was associated in 54.8% of our patients. This was explained by Butler, according to whom disc degeneration would be one of the primary factors of spondylolisthesis [14].

More than two floors were affected by degenerative lesions, which could testify to the duration of the evolution of the pathology before its management.

When analyzing the type of stenosis, the most frequent was a mixed central and foraminal stenosis in 73.8%, which explains well by the anteroposterior reduction of the canal and foramina during spondylolisthesis.

The treatment consisted of a surgical gesture of sagittal stabilization by a rigid arthrodesis (81%) but also a recalibration of the canal and the foramen (71%). This has also been described in other studies [4].

Gill’s operation was performed in 12% of cases because fixation is not systematic considering the fact that listhesis allows the spine to regain sagittal neo-balance [15] [16]. This intervention, although having good results, has tended to be less used for several decades [17].

It should therefore be noted that a reduction, even partial, thus makes it possible to correct lumbar hyperlordosis, pelvic retroversion and certain olisthesic scoliosis. A systematic reduction is not necessary because a new equilibrium has been established as described by Lapras [16]. Too much reduction can then lead to stretching injuries and neurological disorders that did not exist preoperatively.

Laminectomy performed in 100% of cases was associated with discectomy (38%) and foraminotomy (71.4%). Stabilization by osteosynthesis was performed in 81% of cases and currently remains the standard. It must absolutely take into account the pelvic parameters and the sagittal balance of the spine. It was associated with a lordosing interbody cage placement when necessary.

Intraoperatively, 23.5% of patients required a blood transfusion because of epidural bleeding and 7.2% had dural tears. This could be explained by the stenosis of the canal which exposes to adhesions between the sac and the yellow ligament, but also by the presence of numerous epidural varices due to the compression.

The postoperative course was satisfactory in 85.7% of cases, unlike Kone P. [5] who found only 38.5% good progress in non-operated patients. This indicates a benefit of nerve decompression surgery and stabilization of the spine compared to conservative treatment, when there is resistance to medical treatment if the indication is well established and the procedure is well performed [16]. The 14.3% of cases developed complications such as abscess of the psoas-iliac muscles, paraparesis having evolved for 6 months.

All our patients benefited from a systematic postoperative X-ray, as well as scanners or MRI in case of suspicion of recurrence, infection or residual compression, the latter being more indicated because of metallic artifacts on the CT scan. In relation to the material in place. However, the implants must be MRI compatible (titanium).

The main limitations of our study were the absence of cervico-dorso-lumbar spine TV radiographs to study the sagittal balance of the spine and curvatures, the cost of additional examinations and the retrospective nature of the study.