Mean ± SD
When comparing each group's vertebral slippage percentage to its preoperative rank, a statistically significant improvement was observed immediately following surgery until the most recent follow-up. Furthermore, at every follow-up time point, there was no statistically significant difference in the vertebral slip ratio between the MIS-TLIF group and the Open-TLIF group. In both groups, there was a statistically significant difference in the segmental lordosis of the slipping level and the lumbar lordosis between the pre- and postoperative periods. However, when comparing preoperation, immediately postoperatively, and segmental lordosis, no discernible changes were detected between the two groups. On the other hand, there was more segmental lumbar lordosis in the Open-TLIF group. The postoperative interbody fusion rate did not significantly differ between the two groups according to the Bridwell classification ( p < 0.05) (Table 7 ).
Comparison between studied groups regarding radiological outcome
MIS-TLIF | Mini-Open TLIF | |
---|---|---|
Vertebral slip % | ||
Pre-operative | 24.23 ± 4.22 | 25.33 ± 5.33‡ |
Post-operative | 8.67 ± 2.91* | 8.45 ± 2.55*‡ |
Last follow up | 8.99 ± 2.3*† | 8.87 ± 2.1*†‡ |
Lumbar lordosis | ||
Pre-operative | 43.3 ± 7.9 | 42.1 ± 8.5‡ |
Post-operative | 48.1 ± 8.2* | 48.7 ± 7.6*‡ |
Last follow up | 47.2 ± 7.9*† | 48.5 ± 6.2*†‡ |
Focal lordosis | ||
Pre-operative | 5.4 ± 5.9 | 6.5 ± 4.3‡ |
Post-operative | 8.9 ± 7.8* | 9.2 ± 5.1*‡ |
Last follow up | 8.1 ± 6.7*† | 8.2 ± 4.9*†‡ |
Vertebral slip percentage, Lumbar lordosis and focal lordosis comparison between the two groups: * P < 0.05, comparing post-operative data in each group compared to preoperative data, † P > 0.05, comparing data at last follow-up versus immediately following surgery. ‡ P > 0.05, comparing the two groups'
There were two occurrences of superficial incision infection in the open-TLIF group and none in the MIS-TLIF group. Anti-infection medications and frequent dressing changes were used to treat both infections. Two incidences of intraoperative dural tears were recorded in the mini-open-TLIF group; these were immediately repaired, and there was no postoperative leakage of CSF. With two cases of nonunion, the MIS group had a greater rate of pseudoarthrosis. Patients, however, declined to have the procedure repeated.
Numerous published lumbar interbody fusion techniques have been developed with the goal of maintaining spinal alignment, boosting fusion rates, and reducing back and leg discomfort. To achieve smaller surgical wounds, less trauma to surrounding tissue, and a quicker recovery after surgery, Foley et al. introduced MIS-TLIF as an alternative to conventional open-TLIF in the early 2000s. However, similar long-term results for both MIS- and open-TLIF have been previously described in the literature. On the other hand, the positive impacts of MIS-TLIF might be evident in the early stages of recovery, with a shorter period of postoperative opioid use, a shorter hospital stay and an earlier return to work following surgery [ 15 ]. However, strong data are currently lacking on which technique is more clinically effective in treating symptomatic low-grade degenerative spondylolisthesis. This study aimed to compare and evaluate the safety and effectiveness of mini-open-TLIF and MIS-TLIF in the treatment of degenerative spondylolisthesis. To prevent bias, the same surgical team with extensive training in the MIS/mini Open-TLIF approach handled every patient in our study.
The paraspinal muscles sustain more damage when they are separated from their origin/insertion during the mini-open-TLIF. On the other hand, MIS-TLIF involves the use of the paraspinal approach, which aims to dilate the muscles to minimize muscular damage. This was observed in our study because the amount of blood loss was greater in the mini-open-TLIF group. Evaniew et al. [ 3 ] reported that patients who underwent MIS experienced reduced blood loss and quicker surgery. Similar to the findings of a previous study, Qin et al. [ 16 ] demonstrated that MIS-TLIFs reduce blood loss better than do mini-open TLIFs; nevertheless, the authors noted that the MIS-TLIF group needed more time during surgery. Similar outcomes to our investigation were observed in the previous trial, with the MIS group requiring more time during surgery and less blood loss. This could be attributed to the surgical and technique learning curve and familiarity with the approach with fewer bony landmarks and working in a narrow tube.
It is important to consider the cumulative effects of radiation exposure on both the patient and the surgical team [ 7 ]. The smaller operating field, difficulty in seeing bone landmarks, and challenging learning curve associated with MIS-TLIF all contribute to greater radiation exposure duration. According to our study, the prolonged fluoroscopy time needed for percutaneous pedicle screw implantation with MISTLIF accounts for the majority of the increased radiation exposure compared to that of mini-open-TLIF. The radiation exposure period could be shortened with more surgical experience and an improvement in the learning curve, as we noticed in the latter patients who underwent MIS-TLIF [ 14 ].
In the current economic environment, comparing the cost-effectiveness of MIS-TLIF versus mini-open-TLIF is crucial. In two papers published in 2012 and 2014, Parker et al. computed ICERs taking into account both direct and indirect costs; however, the results were inconsistent. A statistically significant difference in cost between the two procedures was not found by our study's cost comparison. However, MIS-TLIF implants were more costly than Open-TLIF implants. This may be explained by the fact that the open-TLIF group required a longer postoperative hospital stay (6.7 ± 1.6 days) together with the indirect cost of delayed return to work in comparison to 3.2 ± 0.9 days in the MIS group. Early hospital discharge minimizes exposure to nosocomial infections, promotes earlier and more frequent mobility, and decreases hospital expenses.
Both groups' back and leg pain VAS scores and ODI scores significantly improved following surgery compared to the preoperative values. This demonstrates that both approaches have proven successful in addressing those suffering from degenerative spondylolisthesis, as reported in the literature [ 1 , 7 , 16 ].
Furthermore, when treating degenerative lumbar illnesses, Heemserk et al. [ 8 ] demonstrated that MIS and open operations have comparable outcomes at two years of follow-up. Qin et al. [ 16 ] reported that when treating single-level low-grade spondylolisthesis, MIS-TLIF seems to be a more effective and safer approach and has a better long-term functional prognosis. The sole difference in the quality-of-life score between the two groups in our study was discovered during follow-up, as the MIS-TLIF group outperformed the Open-TLIF group during the first month in terms of the VAS score for back pain and during the first 6 months in terms of the ODI score for disability ( p < 0.001). The open-TLIF group, however, had a greater VAS score for leg pain relief ( p < 0.05) than did the MIS group. This suggests that although the two groups' clinical performance was similar over time, the MIS-TLIF group performed better than the Open-TLIF group only in terms of early reduction in low back pain and disability. However, Open-TLIF is better for neural tissue decompression because of the large exposure of the approach.
Currently, vertebral slip reduction in spondylolisthesis patients remains a controversial topic. Several studies have shown that satisfaction rates ranging from 75 to 80% can be achieved with in situ fusion without reducing slippage [ 4 , 13 ]. Conversely, other studies have reported a notable prevalence of sagittal imbalance, progressive slippage and pseudoarthrosis. Reducing degenerative spondylolisthesis will somewhat enhance the sagittal lumbosacral balance and the clinical outcome even if it is not required and provide areas for bony fusion [ 4 ]. In our study, both techniques showed significant changes in the slip degree, with no difference between the two techniques. The discrepancy in the reduction data may be limited to patients with high-grade spondylolisthesis, and all our patients had low-grade spondylolisthesis [ 1 ].
Higher grades of spondylolisthesis are characterized by a sagittal imbalance caused by slippage and lordosis loss (LL), which are correlated with disc degeneration. Pelvic retroversion, the result of the pelvis rotating, causes the sacral slope (SS) to decrease and the pelvic tilt (PT) to increase, which restricts the anterior translation of the axis of gravity. Therefore, the restoration of the normal PT range requires the restoration of lumbar lordosis [ 1 , 17 ]. Lower back discomfort can arise from relative kyphosis on the fused segment caused by a decrease in postoperative LL. This, in turn, increases the tensile stress on the spinal structures posterior to the fused segment, including the paraspinal muscles. Therefore, the restoration of segmental and total lordosis is essential for these patients.
Compared to MIS-TLIF, a few surgeons have theorized that open TLIF would allow for more segmental and global lordosis correction. After MIS-TLIF, Dibble et al. [ 2 ] observed greater improvements in segmental lordosis (SL). However, there were no variations in the global lordosis angle compared to that of the Open-TLIF group. On the other hand, the global lordosis angle did not vary. We discovered the same findings during our investigation, with no statistically significant difference in segmental or global lordosis between the two groups. On the other hand, LL and SL significantly changed between the preoperative and postoperative data.
The postoperative interbody fusion rate did not significantly differ between the two groups according to the Bridwell classification (p < 0.05). This finding implies that the fusion rate was unaffected by the surgical technique. In a 5-year follow-up investigation on the fusion findings of MIS-TLIF, Kim et al. [ 9 ], in a narrative review of 14 prospective observational studies and 6 randomized controlled trials, estimated a fusion rate of more than 90%. This is consistent with the results of our study. It could be concluded that for both mini-opening and MIS, the surgical fusion rate may produce good outcomes. However, a number of studies comparing the two methods of treatment have suggested that open-TLIF may provide superior interbody space preparation compared with MIS-TLIF and that MIS-TLIF may result in a lower fusion rate than open-TLIF [ 9 , 14 ]. Many other factors may contribute to this discrepancy, such as the type of graft used (either autograft or synthetic). Sufficient autografts were used in all patients in this study.
According to Goertz et al. [ 6 ] and Krüger M.T. et al. [ 10 ], obese patients who underwent MIS-TLF surgery had a greater incidence of dural tears. The use of TLIF through tube retractors placed directly over the facet avoids the need for retraction of the dura, which avoids the incidence of tears and the avoidance of dural tears during the insertion of the roods or the set esrew at the final step in Open-TLIF. The open-TLIF group experienced an intraoperative dural tear in two patients; however, the MIS-TLIF group experienced no such problems. The use of skin retractors resulted in two cases of skin edge necrosis in the Open-TLIF group, which were further worsened by superficial skin infections. Using a tubular retractor prevented complications in the MIS-TLIF group by preventing significant skin retraction and causing less tissue injury, which minimized the infection rate.
There are several limitations to this study. First, the study was a single-center retrospective study and included only a small number of scenarios. Second, the duration of patient follow-up was somewhat brief. Third, the analysis included only patients who had single-level low-grade spondylolisthesis, and all of them had disc-level lesions at the L4-L5 and L5-S1 levels. More research is required on people with higher-level spondylolisthesis and multisegment disc degenerative diseases.
MIS-TLIF and mini-open-TLIF can be surgically effective in treating single-level degenerative lumbar spine spondylolisthesis in properly selected patients. More specifically, MIS-TLIF can significantly reduce bleeding and the length of hospital stay; nevertheless, MIS-TLIF is associated with increased radiological exposure.
Elsayed Mohamed Selim Ali: (Technique, handling of data, theory, structure, analysis, interpretation, publication search, and writing are all the author's responsibility.). Mohamed Abdeen: (theory, structure, and analysis of literature). Mohammed Khaled Saleh: (Responsible for idea, layout, evaluation, and interpretation).
Open access funding provided by The Science, Technology & Innovation Funding Authority (STDF) in cooperation with The Egyptian Knowledge Bank (EKB). This research was not given a particular grant from any public or private funding organizations.
Declarations.
An ethical approval was done by the IRB, Informed consent was obtained from all individual participants included in the study. Patients signed informed consent regarding publishing their data and photographs.
This study was not presented at any congress or symposium.
All work done at Zagazig university hospitals.
The authors declare no competing interests.
Publisher's Note
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IMAGES
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Learn about the causes, symptoms and treatment options for spondylolisthesis, a condition where a vertebra slips forward over the one below. Grade 2 spondylolisthesis is the most common grade and can be treated with conservative methods or bracing.
Spondylolisthesis is a condition in which a vertebra slips out of place and puts pressure on a nerve. Learn about the types, grades, diagnosis, and treatment options for this spine problem.
Spondylolisthesis is a condition where one vertebra slips forward or backwards relative to the vertebra below. Spondylosis is a fracture of a small bone that connects the vertebrae, which may lead to spondylolisthesis. Learn about the types, grades, symptoms, and treatments of spondylolisthesis.
Spondylolisthesis is a condition where a vertebra slips forward and out of place in the spine. It can cause back and leg pain, nerve compression, and spinal stenosis. Learn about the causes, symptoms, diagnosis, and treatment of spondylolisthesis.
Spondylolisthesis is a condition where one vertebra slips forward over another, causing back pain and spinal deformity. Learn about the causes, stages, symptoms, and treatment options for spondylolisthesis, and how to prevent it from progressing.
Spondylolisthesis is a spinal condition that affects the lower vertebrae. It can cause lower back pain, stiffness, and nerve damage. Learn about the causes, diagnosis, and treatment options for ...
Learn about the causes, symptoms, and treatments of spondylolysis and spondylolisthesis, two common causes of low back pain in children and adolescents. Spondylolysis is a stress fracture in the vertebra, and spondylolisthesis is when the fractured vertebra slips forward.
Spondylolisthesis is a condition where one of the bones in your spine, called a vertebra, slips forward. It can cause lower back pain, sciatica, tight hamstrings and other symptoms. Learn about the causes, diagnosis and treatments of spondylolisthesis.
Spondylolisthesis is a condition where spinal vertebrae slip over one another, causing lower back pain and nerve injury in some cases. Learn about the types, causes, symptoms and treatments of spondylolisthesis, and when surgery may be necessary.
Spondylolisthesis is a condition where a vertebra slips out of place, causing back pain and nerve compression. Learn about the types, risk factors, diagnosis and treatment options, and the potential complications of spondylolisthesis if left untreated.
Spondylolisthesis is a condition in which a vertebra slips out of place, causing back pain, nerve damage and posture problems. Traumatic spondylolisthesis is caused by a fracture of the vertebrae due to injury. Learn about the symptoms, causes, diagnosis and treatment options.
Spondylolisthesis is the slippage of one vertebral body with respect to the adjacent vertebral body causing mechanical or radicular symptoms or pain. It can be due to congenital, acquired, or idiopathic causes. Spondylolisthesis is graded based on the degree of slippage of one vertebral body on the adjacent vertebral body.
Learn about spondylolisthesis, a forward slip of one vertebra over another, and its grades, causes, and symptoms. Grade 2 spondylolisthesis means 50% of a vertebral body has slipped forward over ...
Learn about degenerative spondylolisthesis, a condition where one vertebra slips forward over the one below, often affecting the L4-L5 spinal segment. Find out the causes, symptoms, treatment options and surgery for this spine disorder.
Degenerative spondylolisthesis is a condition that causes low back pain and leg symptoms due to spinal stenosis or nerve compression. It may affect bowel function, but this is not a common symptom and may depend on the severity and location of the slipped vertebra.
Spondylolisthesis is a condition where a vertebra slips forward on the one below, causing back pain and nerve compression. Learn about the causes, grades, and treatments of spondylolisthesis, including surgery for spondyloptosis (grade 5).
When spondylolisthesis causes symptoms, they are typically a result of irritation of nervous tissue, either within the nearby spinal cord or of the adjacent spinal nerves. Such symptoms include low back pain, as well as pain, numbness, tingling, and weakness of one or both lower extremities. This can lead to leg pain, difficulty walking ...
Spondylolisthesis Symptoms. Common symptoms of spondylolisthesis include a sudden pain that radiates down the back or buttocks and becomes more severe when bending or twisting, a sense of weakness in the legs, and an inability to walk without significant pain. ... Grade 4 Spondylolisthesis. In Grade 1 spondylolisthesis, 75% to 100% of the ...
Spondylolisthesis symptoms are categorized into grades 1 to 4 depending on severity. With grade 1 Spondylolisthesis there may be no symptoms at all and patients may be totally unaware they have a defect in the spine. Grade 2 Spondylolisthesis symptoms may include lower back pain, which may, or may not radiate into the legs.
Learn about spondylolisthesis, a condition where one vertebra slips over another, causing back pain and nerve compression. Find out the types, grades, diagnosis and treatment options for L5-S1 spondylolisthesis, a common site of slippage.
The MIS-TLIF group included 34 males and 26 females, with an average age of 40.4 ± 13.6 years. Of those, 45 had grade 1 degenerative spondylolisthesis, and 15 had grade 2 degenerative spondylolisthesis. In the Open-TLIF group, the average age of the 24 females and 36 males was 42.2 ± 13.7 years.