Minimally invasive transforaminal lumbar interbody fusion followed by percutaneous pedicle screw fixation for the treatment of single level lumbar spondylolisthesis: Radiological results of

Evaluating the radiological results of lumbosacral sagittal alignment and advantages of a combined operation using minimally invasive transforaminal lumbar interbody fusion and percutaneous pedicle fixation in treatment for lumbosacral spondylolisthesis.

Journal of military pharmaco-medicine no8-2019 MINIMALLY INVASIVE TRANSFORAMINAL LUMBAR INTERBODY FUSION FOLLOWED BY PERCUTANEOUS PEDICLE SCREW FIXATION FOR THE TREATMENT OF SINGLE LEVEL LUMBAR SPONDYLOLISTHESIS: RADIOLOGICAL RESULTS OF LUMBOSACRAL SAGITTAL BALANCE PARAMETERS Dương Thanh Tung1; Nguyen Van Thach2; Vu Van Hoe3; Nguyen Van Hung3 SUMMARY Objectives: Evaluating the radiological results of lumbosacral sagittal alignment and advantages of a combined operation using minimally invasive transforaminal lumbar interbody fusion and percutaneous pedicle fixation in treatment for lumbosacral spondylolisthesis Subjects and methods: 38 consecutive single-level, low grade (Meyerding grade I or II) lumbar spondylolisthesis patients were prospectively included All patients undergone minimally invasive transforaminal lumbar interbody fusion + percutaneous pedicle fixation operations from st th January 2013 to 30 April 2018 at Gia Dinh’s People Hospital Lateral lumbar spine radiographs in the pre-operative, post-operative periods of each patient were analyzed The results were evaluated by using the radiological parameters: slippage dimension, disc height, disc angle, segmental lordosis angle, lumbar lordosis angle, disc slope angle, sacrum slope Blood loss, operation time, time to first ambulation, length of hospital stays and the complications were also recorded Results: Patient’s average age was 50.66, 73.7% female, 84.2% L4-L5 spondylolisthesis, 15.8% L5-S1 spondylolisthesis, 73.7% degenerative spondylolisthesis, 26.3% isthmus spondylolisthesis All patients had back pain; 84.2% had leg pain; 57.9% had neurogenic claudication After operations, slippage dimension significantly decreased (0.08 mm vs 0.59 mm pre-operation, p < 0.001) The segmental sagittal balance parameters of slipped o o level statistically significant increased post-operation (disc angle: 10.11 vs 7.39 pre-operation, p = 0.0003 disc height: 12 mm vs 9.56 mm pre-operation, p < 0.001; segmental lordosis angle: o o 16.83 vs 13.83 pre-operation, p = 0.003) The lumbar regional sagittal balance parameters (lumbar lordosis, disc slope angle, sacrum slope) showed no significant changes post-operation Mean operation time was 182.05 minutes, mean blood loss was 140.79 mL Average time to first ambulation was 25.89 hours and average postoperative hospital stays was 8.5 days Gia Dinh’s People Hospital Viet Duc Hospital 103 Military Hospital Corresponding author: Duong Thanh Tung (thanhtungdr@yahoo.com) Date received: 13/09/2019 Date accepted: 16/10/2019 206 Journal of military pharmaco-medicine no8-2019 Conclusions: The minimally invasive transforaminal lumbar interbody fusion + percutaneous pedicle fixation operation is a safe and efficient surgical technique in treatment of spondylolisthesis It can reduce slippage dimension, restore the segmental sagittal balance parameters (disc angle, disc height, segmental lordosis angle) with the advantages of minimally invasive techniques such as less complications, less blood loss and shorter time to the first ambulation post operation * Keywords: Transforaminal lumbar interbody fusion; Percutaneous pedicle fixation; Sagittal balance parameters; Sagittal alignment parameters INTRODUCTION Spondylolisthesis is defined as the slippage of one vertebra over the vertebra immediately below it [1] It results in spinal instability, spinal stenosis, pinch of nerve structures that cause back pain, sciatica, neurogenic claudication or cauda equina syndrome [2] Lumbopelvic malalignment plays a significant role in multiple spinal conditions Recently, several studies reported the close relationship between spondylolisthesis and sagittal alignment and the reduction of slippage, restoration of disc height and correction of changes of sagittal balance parameters help to improve clinical symptoms, increase the fusion rate, and minimize the adjacent segment degeneration syndrome after surgery [2, 3] Transforaminal lumbar interbody fusion (TLIF) followed by pedicle fixation (PF) has been a commonly used surgical option for treating spondylolisthesis This operation (TLIF + PF) provided solid fixation of spinal segments while restoring a proper disc height and sagittal balance [4, 5, 6] In recent years, minimally invasive surgery (MIS) is the new trend in spinal fusion surgery TLIF + PF using minimally invasive techniques (Minimally Invasive Transforaminal Lumbar Interbody Fusion + Percutaneous Pedicle Fixation: MISTLIF + PPF) has gained popularity over the years with the advantages of smaller incisions, reduced trauma to paraspinal muscles, decreased intra-operative blood loss, shorter hospital stays, and decreased rates of operative site infection, all of which contribute to lower postoperative morbidity and expedite post-operative recovery [6, 7] At Vietnam, there hasn’t been any studies about the effect of MIS on improvement of lumbarsacral sagittal balance in lumbar spondylolisthesis The purpose of this study was: To evaluate the radiological outcomes of lumbosacral sagittal alignment parameters and advantages of the MIS-TLIF + PPF operation in treatment for patients with low grade (Meyerding grade I or II) lumbosacral spondylolisthesis SUBJECTS AND METHODS Subjects 38 patients with a single level, low grade (Meyerding grade I or II) lumbar spondylolisthesis who underwent a MIS-TLIF + PPF operation at Gia Dinh’s People Hospital from 1st January 2013 to 30th April 2018 were included in the study 207 Journal of military pharmaco-medicine no8-2019 * Inclusion criteria: - The presence of single-level, low-grade (Meyerding grade I or II) spondylolisthesis - There is surgical indication for spondylolisthesis (persistence of significant symptoms that correlated with the diagnostic imaging findings, failure with conservative treatment for at least months) * Exclusion criteria: Patients with high grade (Meyerding grade III or IV) spondylolisthesis, metabolic bone diseases, scoliosis, infections, spinal traumas, tumors, and multilevel fusions Methods * Surgical technique: All MIS-TLIF + PPF procedures were done via unilateral approach Under fluoroscopic guidance, a cm paraspinal skin incision is made between the L4-5 or A L5-S1 pedicles on antero-posterior images After an incision is made on the lumbodorsal fascia between the multifidus and longissimus muscles, sequential widening of the incision is made using tubular dilators, and a 24 mm working channel Quadrant (Medtronic, Tennessee, USA) is docked Under microscope visualization, total facetectomy and partial laminectomy are performed using a combination of osteotome and high-speed burr, and kerrison rongeurs The ligamentum flavum is resected and nerve root is retracted medially Complete discectomy is performed, and meticulous preparation of the central and contralateral endplates is performed with angled ring curettes A banana-shaped crescent cage (Medtronic, Tennessee, USA), filled with morselized bone fragments obtained from laminofacetectomy is inserted into the disk space (fig 1) B Fig 1: Performing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) (A: 24 mm working channel Quadrant is docke; B: Putting the Crescent cage in to the disc space) (Source: Author, real operation on patient Ngo T K T., No of hospital admission: 19.043560) 208 Journal of military pharmaco-medicine no8-2019 Then, percutaneous pedicle screws (Sextant, Medtronic, Tennessee, USA) are inserted under fluoroscopic guidance, and adequate sized pre-lordosed rods are fitted, and the wounds are sutured layer by layer (fig 2) A B Fig 2: Performing percutaneous pedicle fixation (PPF) (A: Inserting the sextant screws into the pedicle; B: Manipulations are performed under fluoroscopic guidance of C-arm images) (Source: Author, real operation on patient Ngo T K T., No of hospital admission: 19.043560) * Groups of variable: - Characteristics of single, low grade spondylolisthesis: Age, sex, clinical symptoms, pre-operation time of pain, level of spondylolisthesis, type of spondylolisthesis - Peri-operative parameters: Operation time, blood loss, blood infusion, drainage, time to first ambulation, hospital stays, complications - The radiology spinal sagittal balance parameters: Were measured from conventional lumbar spine radiographs in lateral view, at the pre-operation and post-operation periods of each patient using AUTOCAD software Resetting the measurement scale to a figure so that the length of 1,000 measurement units corresponded to the actual 1-cm length of the anatomical structures on X-ray, according to the formula: Measurement scale = 1,000 α α: The number of measurement units measured by Autocad software at the ratio of 1/1 of the size reference segment on X-ray, represented the actual 1-cm length These measured parameters included (described in fig 3): - Slippage dimension (SD): measured dimension from posterior wall of superior 209 Journal of military pharmaco-medicine no8-2019 vertebral body to posterior wall of inferior vertebral body - Disc height (DH): Average of the anterior and posterior heights of the disc space - Segmental lordosis angle (SLA): The angle measured from the superior endplate of the upper vertebra with the inferior endplate of the lower vertebra However, the SLA of the L5-S1 level was measured between the superior endplate of L5 and the upper endplate of the sacrum - Lumbar lordosis angle (LLA): The angle measured between the superior endplate of L1 and the upper endplate of the sacrum - Disc slope angle (DSA): The angle measured between the line connecting the mid-point of anterior disc space to the mid-point of posterior disc space and a horizontal line - Sacral slope (SS): The angle measured between the superior plate of S1 and a horizontal line Fig 3: The radiological lumbosacral sagittal balance parameters (A: The measured value of the size reference segment on X-ray after resetting the measurement scale to ensure that the length of 1,000 measurement units corresponded to the actual 1-cm length; SD: Slippage dimension; DH: Disc height = (a + b/2); DA: Disc angle; SLA: Segmental lordosis angle; LLA: Lumbar lordosis angle; DSA: Disc slope angle and SS: Sacral slope) (Source: Author, real operation on patient Ha T K N., No of hospital admission: 16.21666) 210 Journal of military pharmaco-medicine no8-2019 * Statistical analysis: Data were expressed as mean ± standard deviation in continuous variations or as the number of patients with the percentage in categorical variations, the different of pre-operation and post-operation radiologic parameters such as SD, DA, SLA, LLA, DSA, SS were analyzed using either the paired t-test or Wilcoxon signed-rank test p < 0.05 was considered significant All statistical analysis was performed using SPSS version 20 RESULTS AND DISCUSSION Demographic characteristics of the patients - Age (years): 50.66 ± 10.24 - Sex: Female 28 patients (73.7%); male: 10 patients (26.3%) - Clinical symptoms: Back pain: 38 patients (100%); neurogenic claudication: 22 patients (57.9%); leg pain: 32 patients (84.2%) - Pre-operation time of pain: 34.5 ± 31.3 months - Level of spondylolisthesis: L4-L5: 32 patients (84.2%); L5-S1: patients (15.8%) - Type of spondylolisthesis: Isthmus: 10 patients (26.3%); degeneration: 28 patients (73.7%) These results were not different from other studies Boissiere studied thirty-nine patients, who were experienced MIS-TLIF + PPF for spondylolisthesis, mean age of 46 ± 10.1; 21 female (53.84%), 18 men (46.16%); 29 patients (74%) with degenerative spondylolisthesis, 10 patients (26%) with isthmic spondylolisthesis [5] In the study on 22 MIS-TLIF + PPF operations for spondylolisthesis, patients had spondylolisthesis, (75%) were of degenerative type, and only patients (25%) were of isthmic type [6] Paul Park studied 40 symptomatic spondylolisthesis patients, who were experienced MIS-TLIF + PPF operations, the mean age was 56; in the clinical series, 30 patients (75%) carried a diagnosis of degenerative spondylolisthesis and the remaining 10 patients (25%) had isthmic spondylolisthesis The most common level treated was L4-5 (28 patients = 70%) followed by L5-S1 (8 patients = 20%) and then L3-4 (2 patients = 5%) patients underwent a 2-level fusion involving L4-L5 and L5-S1 [7] Studies by other authors also showed that back pain is a major symptom and presented in most patients, while other symptoms such as nerve root pain, neurogenic claudication, bladder and bowel dysfunction may present in different rates Matsunaga, Ijiri, and Hayashi, in a study with at least a years follow-up evaluation, reported that the most common symptoms were low back pain and gluteal pain, which were present in 98% of patients Lower extremity pain and numbness were also present in 48% of patients, whereas intermittent claudication was seen in 13% and one patient had bowel and bladder dysfunction The authors examined annually total of 145 patients with spondylolisthesis for a minimum of 10 years follow-up evaluation, showed that back pain was the main symptom, back pain accompanied with 211 Journal of military pharmaco-medicine no8-2019 leg pain and neurogenic claudication in 68% of patients, with only leg pain in 32% of patients, cauda equina syndrome was very rare Back pain was unique symptom in 32% of patients [1] Peri-operative parameters Mean operation time was 182.05 ± 36.22 minutes from skin incision to final wound closure, mean blood loss was 140.79 ± 72.46 mL, no cases of blood transfusion and drainage, mean time to first ambulation was 25.89 ± 5.50 hrs and mean post-operative hospital stays was 8.5 ± 3.28 days There was only case (2.63%), the cage pushed disc material to the other side that pressed on the opposite nerve root, required microscopic discectomy and the subject went to get good outcome There were no dural tears, no postoperative infections and no neurologic deficits observed post-operation The average operation time in the study was 182.05 ± 36.22 minutes, not significantly different from Rouben's study, the average operation time of MIS-TLIF + PPF was 183 minutes [8] Khan also reported no difference in the duration of surgery between the conventional open surgery and MIS surgery [9] The obvious advantages of minimally invasive surgery is that there was very little blood loss in surgery (140.78 ± 72.46 mL), no cases of blood transfusion and drainage In conventional open surgery, a lot of blood loss was common Wang recorded an average blood loss was 364 ± 23 mL, post-operative drainage blood was 375 ± 26 mL, blood transfusions were required in many cases and most of them were drained in the study of conventional open TLIF + PPF [10] Limiting blood loss is an important point since it leads to reduced blood transfusions and the risks of blood transfusion [5, 10] Average time to first ambulation in the study was 25.89 ± 5.50 hrs, very early compared to conventional open surgery Rouben reported the first time to leave the bed after operation in open surgery was 67.2 ± 38.4 hours [8] Post-operation and pre-operation radiologic sagittal balance parameters Table 1: Post-operation and pre-operation radiologic parameters Parameter Post-operation Pre-operation p-value SD (mm) 0.08 ± 0.16 0.59 ± 0.28 < 0.001 DA (o) 10.11 ± 5.44 7.39 ± 5.05 0.0003 12 ± 2.6 9.56 ± 2.6 < 0.001 SLA (o) 16.83 ± 6.74 13.83 ± 7.29 0.003 LL (o) 35.25 ± 8.83 33.97 ± 11.49 0.254 DSA (o) 14.20 ± 8.92 15.24 ± 9.49 0.228 SS (o) 32.35 ± 7.54 30.76 ± 9.05 0.172 DH (mm) 212 Journal of military pharmaco-medicine no8-2019 Spondylolisthesis may induce the clinical syndromes, alter biomechanics and imaging characteristics, reduce disc heights and lead to abnormal compensatory postural changes of segmental, regional, and global sagittal balance of spine They slowly evolve neurological deficits from stretching or compression of neural elements, and chronic pain [2, 5] One of the central goals of surgery is to correct spinal deformity of spondylolisthesis to alleviate all these symptoms MIS is the new trend in spinal fusion surgery The objectives of MIS-TLIF + PPF operation are to stabilize the spinal segment, restore lordosis, obtain inter-vertebral fusion, and perform decompression of the neurological structures when required [1, 2, 5] The majority of studies on the effectiveness of MIS-TLIF on treatment of lumbosacral spondylolisthesis are interested in improving patient’s clinical symptoms and functions However, analysis of sagittal spinal alignment seems to be an important factor for the full assessment of spondylolisthesis Indeed, as shown by Kumar et al is that neglecting the role of sagittal alignment in treatment of spondylolisthesis may lead to poor clinical outcome and patient dissatisfaction [1] Based on changes in spinal sagittal balance parameters, Gille divided spondylolisthesis into types, with there was a dynamic continuum from type (balanced spines or a local compensation) to type (significant global malalignment) He observed that patients mistreated as type with a single level posterior fusion, while they actually were type or 3, required revision surgery to prolong constructs more frequently [2] * The effects of reduction spondylolisthesis (decreasing SD) of In this study, SD decreased significantly post-operation (0.08 ± 0.16 mm vs 0.59 ± 0.28 mm pre-operation, p < 0.001), meant the slippage was well corrected, the MIS-TLIF + PPF operation has effectively reduced spondylolisthesis The reduction of SD leads to improving the clinical symptoms and increasing the rate of successful lumbar interbody fusion [1, 2, 5] Because of forward slippage of the upper vertebral body, there was an accelerated degeneration of the inter-vertebral disc, resulting in a backward bulge of the annulus fibrosis The surface area of contact between the inferior endplate of upper vertebra and the superior endplate of lower vertebra was reduced The exiting upper nerve root, which wraps around the pedicle of upper vertebral body, tends to be directly over the interspace rather than behind the body of upper vertebral body as it normally is The upper nerve root is entrapped dorsally by a mass created by exuberant fibrous tissue at the isthmus defect (in isthmus spondylolisthesis) and ventrally by an L5-S1 disc protrusion or the overriding postero-superior corner of the lower vertebral body In rare cases the entire caudal equine roots may be compressed by the posterior dome of the lower vertebral body The reduction of the spondylolisthesis will correct a part of these abnormalities [1, 4] 213 Journal of military pharmaco-medicine no8-2019 Furthermore, when reduction surgery is not performed, and lumbar interbody fusion is considered, there is a smaller surface area of endplates for the placement of the graft, a condition not conducive to fusion When the slippage is corrected, the surface area is restored, improves the fusion rate [4] * The effects of the restoration of segmental sagittal balance parameters (DA, DH, SLA): This operation also significantly improved segmental parameters of sliding segment (DA: 10.11 ± 5.44o vs 7.39 ± 5.05o pre-operation, p = 0.0003 DH: 12 ± 2.6 mm vs 9.56 ± 2.6 mm pre-operation, p < 0.001; SLA: 16.83 ± 6.74o vs 13.83 ± 7.29o pre-operation, p = 0.003) Many authors suggested the decreases of DA, DH result in decreasing of SLA in lumbar spine, and small SLA may lead to increase of loading strain and adversely prompt the adjacent segmental degeneration and restoration of SLA prevent adjacent segment degeneration and also to reduce the risk of postoperative low back pain [2, 12] Boissiere noted that the TLIF + PPF was highly efficient to restore SLA and the restoration of SLA is a key-factor to prevent adjacent segment degeneration [5] Therefore, it is believed that care and attention should be given to introduce DA, DH and SLA in the normal range [2, 5, 12] In spondylolisthesis, there are patterns of morphological changes in the disc Spinal morphology shows a clear decrease in DA and SLA of the spondylolisthesis 214 level The decreases of DA and SLA at the level of listhesis are more distinct in degenerative spondylolisthesis than isthmus spondylolisthesis The small DA of the spondylolisthesis group might be a predisposing factor to the development of spondylolisthesis or a compensatory mechanism to the ventral slippage of the vertebra [1] Degenerative disc disease occurs later in the natural history of spondylolisthesis, resulting in single level disc degeneration and usually induce reduction of the DH corresponding to the compromised level The reduction of DH will narrow the foraminal size and decrease SLA of affected segments [3, 11] Tang found that from normal model to mildly, moderately and severely decreased DH model, the SLA decreased 5°, 10° and 15°, respectively [12] The restoration of DH is essential to indirect decompress inter-vertebral foramen, increase the SLA, relax nerve roots, as well as improve clinical post-operatory results [2, 11, 12] Many authors also reported that decreasing of DH was accompanied with the decreasing of SLA at fused segments post operation [2, 12] Gaffey J.L concluded that’s there was significant correlation between implant height and SLA and an increasing implant height produced a significant increase in SLA [12] In the report of 26 patients undergone lumbar interbody fusions, Kim confirmed a loss of SLA had a significant correlation with decrease of DH resulting from cage subsidence [10] Journal of military pharmaco-medicine no8-2019 Results of researches from other authors also showed that the MIS-TLIF + PPF operation significantly improved segmental sagittal balance parameters of slipped segments Boissiere performed this surgery on 39 patients with spondylolisthesis, DH increased 0.37 ± 0.80 mm vs 0.26 ± 0.9 mm pre-operatively at L5-S1 segment; 0.35 ± 0.06 mm vs 0.26 ± 0.07 mm pre-operatively at L4-L5 segment, SLA increased 33.8 ± 6.5o vs 25.3 ± 7.8o pre-operatively at segment L4-L5; 31 ± 4.7o vs 19.4 ± 6.7o pre-operatively at L5-S1 segment [5] Choi performed this surgery on 22 patients, DH increased 8.8 ± 1.8 mm compared with 7.0 ± 1.9 mm pre-operatively SLA increased 16.5 ± 4.9o compared to 13.3 ± 4.3o pre-operatively, DA increased by 10.8 ± 3.05o compared to 8.8 ± 3.5o pre-operatively [6] * The changes of lumbar regional lumbar sagittal balance parameters (LL, DSA, SS): according to the changes of sagittal balance parameters (segmental, regional, and global analysis parameters) in processes of spondylolisthesis from mind to severe stages Type 1a corresponds to balanced spines with preserved local and global sagittal balance Type 1b includes a local compensation with disc flexion and loss of segmental lordosis Type 2a and 2b include a pelvis index and LL mismatch This is due to multi-segmental degenerative disc disease responsible for a loss of LL Type represents a significant global malalignment resulting from overrun local and regional compensatory mechanisms (thoracic and pelvic) More aggressive surgical treatment may be considered to correct sagittal malalignment, especially in case of significant clinical sagittal imbalance Treating only the slippage level may lead to a poor clinical outcome [2] In this study, the lumbosacral regional In this study, the lumbosacral regional parameters (LL, DSA, SS) showed insignificant modifications postoperatively sagittal balance parameters (LL, DSA, SS) Progressive geometrical changes in the lumbosacral junction are manifested clinically by compensatory postural changes characteristics of high-grade spondylolisthesis Buckland et al studied different posture patterns between patients with spondylolisthesis concluded that patients in mild-to-moderate malalignment did not recruit regional parameters such as pelvis tilt until moderate-to-severe malalignment was present Gille proposed a classification for spondylolisthesis the fact that all patients belong to lower showed no significant modifications postoperatively This can be explained by grade (I, II) spondylolisthesis, processes of disease only affect the segmental sagittal imbalance at slipped level, not in the lumbar region It is also possible that surgery is performed at the slipped level, which can restore only slipped segmental parameters Complete correction of regional or global sagittal imbalance requires more invasive surgical procedures, such as multi-level fusion or osteotomies [5] 215 Journal of military pharmaco-medicine no8-2019 The results from this study were similar to most studies of other authors Study by Boissiere showed the differences of preoperative and postoperative radiologic parameters of MIS-TLIF + PPF operation: DH, SLA significantly increased postoperatively (DH: 0.37 ± 0.80 mm vs 2.6 ± 0.9 mm pre-operation, p < 0.01 at L5-S1 levels; 0.35 ± 0.06 mm vs 0.26 ± 0.07 mm pre-operation, p < 0.01 at L4-L5 levels SLA: 33.8 ± 6.5o vs 25.3 ± 7.8o pre-operation, p < 0.01 at L4-L5 levels; 31o ± 4.7 o vs 19.4o ± 6.7 o pre-operation, p < 0.01 at L5-S1 levels) The sagittal balance global analysis (pelvis Tilt, LL) showed no significant modifications postoperatively [5] Similarly, studies by Boissiere [5] and Choi [6] also showed that the lumbosacral regional sagittal balance parameters (LL, DSA, SS) showed no significant changes after surgery CONCLUSIONS The ideal goals of surgical management in treatment of spondylolisthesis are to maintain, reduce, or restore a physiological post-operative spinal balance Our study demonstrates that MIS-TLIF + PPF approach achieves the reduction of slippage (SD: 0.08 ± 0.16 mm post-operation vs 0.59 ± 0.28 mm pre-operation, p < 0.001), restoring of proper disc height (DH: 1.20 ± 2.6 mm post-operation vs 9.56 ± 2.6 mm pre-operation, p < 0.001) and correct segmental sagittal balance of lumbosacral spondylolisthesis (DA: 10.11 ± 5.44o postoperation vs 7.39 ± 5.05o pre-operation, p = 0.0003; SLA: 16.83 ± 6.74o post216 operation vs 13.83 ± 7.29o pre-operation, p = 0.003) However, MIS-TLIF + PPF didn’t change lumbosacral regional sagittal balance parameters (LL, DSA, SS showed no significant modifications postoperatively) The absence of dural tears and infections, the limited blood loss and shorter time to first ambulation in our series show us the safe and the advantages of this operation These makes us consider MIS-TLIF + PPF as a safe and efficient surgical technique in treatment spondylolisthesis REFERENCES H R Winn Pediatric spondylolisthesis In: Youmans Neurological Surgery 6th edition Elsevier Saunders, People’s Republic of China 20111, pp.2935-2945 O Gille, H Bouloussa, S Mazas et al A new classification system for degenerative spondylolisthesis of the lumbar spine Eur Spine J Springer-Verlag 2017, pp.5275-5274 K.S Emanuel, I Kingma, M.N Helder et al Response to: A dose–response relationship between severity of disc degeneration and intervertebral disc height in the lumbosacral spine Arthritis 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Aesculap AG & Co KG Tuttlingen, https://www.spineuniverse.com/professional/r esearch/technology/surgical/lumbar 2012 Boissiere L, Perrin G, Rigal J, Michel F et al Lumbar-sacral fusion by a combined approach using interbody peek cage and posterior pedicle-screw fixation: Clinical and radiological results from a prospective study Orthopaedics & Traumatology: Surgery & Research 2013, 99, pp.945-951 Journal of military pharmaco-medicine no8-2019 W.S Choi, J.S Kim, K.S Ryu et al Clinical study minimally invasive transforaminal lumbar interbody fusion at L5-S1 through a unilateral approach: Technical feasibility and outcomes Biomed Research International, http://dx.doi.org/10.1155/2016/2518394 2016 Paul Park, Kevin T Foley Minimally invasive transforaminal lumbar interbody fusion with reduction of spondylolisthesis: Technique and outcomes after a minimum of years’ follow-up Neurosurg Focus 2008, 25 (2), pp.1-7 Rouben D, Casnellie M, Ferguson M Long-term durability of minimal invasive posterior transforaminal lumbar interbody fusion: A clinical and radiographic follow-up J Spinal Disord Tech 2011, 24, pp.288-296 Khan A, Terman SW, Yee T et al Comparison of perioperative outcomes following open versus minimally invasive transforaminal lumbar interbody fusion in obese patients Neurosurg Focus 2013, 35 (2), pp.10-15 10 Wang J, Zhou Y, Zhang ZF et al Minimally invasive or open transforaminal lumbar interbody fusion as revision surgery for patients previously treated by open discectomy and decompression of the lumbar spine Eur Spine J 2011, 20, pp.623-628 11 T.C Martinelli, E.A Effgen, M.A.N Brazolino, I.M Cardoso et al Original article evaluation of the discal height gain and lumbar lordosis variation obtained by the techniques of transforaminal and posterior lumbar intersomatic fusion Rev Bras Ortop 2018, (5), pp.527-553 12 S Tang, X Meng Does disc space height of fused segment affect adjacent degeneration in alif? A finite element study Turkish Neurosurgery 2011, 21 (3), pp.296-303 217 ... minimally invasive surgery (MIS) is the new trend in spinal fusion surgery TLIF + PF using minimally invasive techniques (Minimally Invasive Transforaminal Lumbar Interbody Fusion + Percutaneous Pedicle. .. spondylolisthesis The reduction of SD leads to improving the clinical symptoms and increasing the rate of successful lumbar interbody fusion [1, 2, 5] Because of forward slippage of the upper...Journal of military pharmaco-medicine no8-2019 Conclusions: The minimally invasive transforaminal lumbar interbody fusion + percutaneous pedicle fixation operation is a safe