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【Objective】 To compare the short-term clinical effects of oblique lateral interbody fusion （OLIF） and transforaminal lumbar interbody fusion （TLIF） for treating single-segment lumbar spondylolisthesis. 【Methods】 We retrospectively analyzed the data of 68 patients with single-segment degenerative lumbar spondylolisthesis from January 2019 to February 2020. According to different surgical methods， the patients were divided into OLIF+ anterior screw fixation group （33 cases） and TLIF + posterior pedicle screw fixation group （35 cases）. The operation time， intraoperative blood loss， postoperative drainage， postoperative hospital stay and complication rate were compared between the two groups of patients. The disc height （DH）， lumbar lordosis （LL）， fused segmental lordosis （FSL）， foraminal height （FH）， and spondylolisthesis angle （SA） were measured before and after surgery and during follow-up. The visual analogue scale （VAS） of waist pain and the Oswestry disability index （ODI） were used to evaluate the short-term clinical efficacy. 【Results】 The operation time， intraoperative blood loss， postoperative drainage， and postoperative hospital stay were less in OLIF group than in TLIF group （all P0.05）. The two groups had statistically significant differences in DH and FH after surgery （P0.05）. There were six （18.2%） and five （14.3%） cases of complications in OLIF group and TLIF group， respectively， with no significant difference （P>0.05）. 【Conclusion】 OLIF and TLIF are equally safe and effective in treating single-segment lumbar spondylolisthesis. However， OLIF combined with anterior screw fixation has the advantages of less surgical trauma， less blood loss， shorter operation time， reduced postoperative hospital stay and shorter recovery time. Therefore， it is a more minimally invasive surgical option.
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Objective To study the biomechanical properties of porous titanium cages used for different lumbar interbody fusion surgeries. Methods The three-dimensional (3D) finite element model of the lumbar spine was constructed, and mechanical parameters of porous materials were obtained by mechanical test. The biomechanical properties of porous titanium cages in anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), direct lateral interbody fusion (DLIF) were compared. Results After lumbar interbody surgery, the predicted range of motion (ROM) and the maximum stress in cage of DLIF model and ALIF model were substantially lower than those of PLIF model and TLIF model. The maximum stress in endplate of DLIF model, ALIF model and TLIF model were obviously lower than that of PLIF model. Conclusions DLIF with the porous cage showed advantages in biomechanical properties, which was simple to operate and suitable for minimally invasive surgery in clinical practice. DLIF performed the superior comprehensive properties.
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Objective To compare biomechanical properties of pedicle screw with different axial angles and interbody cage with different positions for unilateral transforaminal lumbar interbody fusion (TLIF) surgery. Methods The normal L3-5 finite element (FE) model was established and validated. Then one bilateral TILF reconstruction FE model and four unilateral TILF reconstruction FE models with different pedicle screw-cage combination types at L4-5 level were constructed, respectively. Namely, Model A (a small axial angle-implanted screw and an ipsilaterally-placed cage), Model B (a small axial angle-implanted screw and a contralaterally-placed cage), Model C (a large axial angle-implanted screw and an ipsilaterally-placed cage), Model D (a large axial angle-implanted screw and a contralaterally-placed cage). The range of motion (ROM) of 4 reconstruction models under various physiological stresses as well as the maximum Von Mises stresses on pedicle screw, cage-L4 inferior endplate were compared. Results The ROMs at fusion segment (L4-5) in 4 unilateral TLIF reconstruction models were significantly decreased compared with the normal model, but they were still larger than bilateral TLIF reconstruction model. For 4 unilateral TLIF reconstruction models, Model C showed the largest decrease in stability, and the ROM of Model C was 50.7%, 89.9%, 90.3% of the normal model in flexion-extension, lateral bending, axial rotation, respectively. When comparing the maximum Von Mises stress of posterior pedicle screw and cage-L4 inferior endplate in 4 unilateral TLIF reconstruction models, Model C could bear relatively smaller stress under most loading modes, except in ipsilateral lateral bending and axial rotation. Conclusions The unilateral TLIF reconstruction model with a large axial angle-implanted screw and an ipsilaterally placed-cage can achieve the optimal stability. By narrowing the difference in stability with the bilateral TILF model, the unilateral TLIF reconstruction model can reduce the risk of screw failure and cage subsidence, which is worth of clinical application.
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Objective To compare biomechanical properties of pedicle screw with different axial angles and interbody cage with different positions for unilateral transforaminal lumbar interbody fusion (TLIF) surgery.Methods The normal L3-5 finite element (FE) model was established and validated.Then one bilateral TILF reconstruction FE model and four unilateral TILF reconstruction FE models with different pedicle screw-cage combination types at L4-5 level were constructed,respectively.Namely,Model A (a small axial angle-implanted screw and an ipsilaterally-placed cage),Model B (a small axial angle-implanted screw and a contralaterally-placed cage),Model C (a large axial angle-implanted screw and an ipsilaterally-placed cage),Model D (a large axial angle-implanted screw and a contralaterally-placed cage).The range of motion (ROM) of 4 reconstruction models under various physiological stresses as well as the maximum Von Mises stresses on pedicle screw,cage-L4 inferior endplate were compared.Results The ROMs at fusion segment (L4-5) in 4 unilateral TLIF reconstruction models were significantly decreased compared with the normal model,but they were still larger than bilateral TLIF reconstruc-tion model.For 4 unilateral TLIF reconstruction models,Model C showed the largest decrease in stability,and the ROM of Model C was 50.7％,89.9％,90.3％ of the normal model in flexion-extension,lateral bending,axial rotation,respectively.When comparing the maximum Von Mises stress of posterior pedicle screw and cage-L4 inferior endplate in 4 unilateral TLIF reconstruction models,Model C could bear relatively smaller stress under most loading modes,except in ipsilateral lateral bending and axial rotation.Conclusions The unilateral TLIF reconstruction model with a large axial angle-implanted screw and an ipsilaterally placed-cage can achieve the optimal stability.By narrowing the difference in stability with the bilateral TILF model,the unilateral TLIF reconstruction model can reduce the risk of screw failure and cage subsidence,which is worth of clinical application.
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STUDY DESIGN: Literature review. OBJECTIVES: The aim of this study was to demonstrate surgical strategies for successful minimally invasive transforaminal lumbar interbody fusion (TLIF). SUMMARY OF LITERATURE REVIEW: Although many studies have reported the benefits and disadvantages of minimally invasive TLIF, few have described surgical strategies to improve the success rate or to reduce complications. MATERIALS AND METHODS: We searched for studies reporting the clinical and radiological outcomes of minimally invasive TLIF, and analyzed the optimal indications, technical pitfalls, and tips for successful surgical outcomes. RESULTS: The ideal candidate for minimally invasive TLIF is a patient with single or 2-level low-grade adult degenerative or isthmic spondylolisthesis. Incomplete decompression, dura tearing, nerve root injury, and implant-related complications were found to be the most commonly reported adverse events, especially in the early periods of a surgeon's experience. Precise positioning for skin incision and tube insertion, complete neural decompression, proper interbody preparation for bone graft and cage insertion, and the correct placement of percutaneous pedicle screws are critical strategies for successful surgical outcomes. Fully understanding the surgical pitfalls and tips described in this review is also important to avoid potential complications. CONCLUSIONS: It is imperative not only to carry out a comprehensive preoperative evaluation and proper patient selection, but also to perform meticulous surgical procedures with thoughtful considerations of potential pitfalls, in order to improve the success rate and to reduce the complications of minimally invasive TLIF.
Subject(s)
Adult , Humans , Decompression , Patient Selection , Pedicle Screws , Skin , Spondylolisthesis , Tears , TransplantsABSTRACT
Objective To analyze the clinical feasibility of unilateral transforaminal lumbar interbody fusion (TLIF) for treating lumbar degenerative diseases by finite element method. Methods Based on CT scan data, three-dimensional (3D) finite element models of the normal L3-5 segments under physiological status (intact lumbar model), L4/5 with unilateral pedicle screw fixation plus interbody fusion (unilateral TLIF model) and L4/5 with bilateral pedicle screw fixation plus interbody fusion (bilateral TLIF model) were established by using Mimics, Pro/E, ANSYS software, respectively. Preload of 500 N and load of 10 N•m torque were applied on the superior surface of the L3 segment to simulate 5 physiological activities: body upright, flexion, extension, left lateral bending and right axial rotation. The deformation and stress distributions in vertebral body, vertebral discs, pedicle screw and cage under different loads were then recorded and analyzed to compare mechanical properties of the two fixation methods. Results The deformation of L3-5 segments fixed with unilateral TLIF or bilateral TLIF decreased as compared to the intact lumbar model; the stresses in cage reached the maximum in both unilateral TLIF model and bilateral TLIF model during back extension, meanwhile peak stresses on pedicle screws in unilateral TLIF were significantly higher than those on bilateral TILF model, with the peak stress of 463.39 MPa during back extension. ConclusionsUnilateral TLIF can be selected as a method for treating lumbar degenerative diseases; however, its stability was inferior to bilateral TLIF due to the higher peak stress. Therefore, less stretch exercises may be safe for patients during rehabilitation to avoid surgery failure or pedicle screw fracture.
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STUDY DESIGN: A retrospective study OBJECTIVES: To introduce the technique of minimally invasive transforaminal lumbar interbody fusion and examine its clinical and radiologic results. SUMMARY OF LITERATURE REVIEW: Transforaminal lumbar interbody fusion with a mini-incision using a tubular retractor was recently developed. The aim of this procedure is to reduce the approach-related morbidity and achieve better results in an effective and safe manner. MATERIALS AND METHODS: Thirty eight patients were followed up for more than 1 year. Their mean age was 57 years and the mean follow-up was 19 months. The diagnosis was spinal stenosis, spondylolisthesis and recurred herniated nucleus pulposus in 22, 14 and 2 patients, respectively. The Oswestry disability index, intervertebral disc space height, fusion rate and complications were evaluated. RESULTS: The Oswestry disability index improved from 30 points (range, 50~16 points) to 10 points (range, 2-24 points) at the last follow-up. Thirty-four patients (90%) showed excellent or good results. The intervertebral disc space height increased from 8.7 mm to 10.8 mm. Two cases showed nonunion but the clinical results were good. Complications included one case of infectious spondylitis requiring antibiotics, one case of cage dislodgement requiring additional surgery and one case of a pedicle screw malposition showing no clinical symptoms. CONCLUSIONS: Minimally invasive transforaminal lumbar interbody fusion reduced the soft tissue injury and blood loss and shortened the recovery period compared to the traditional open techniques.
Subject(s)
Humans , Anti-Bacterial Agents , Follow-Up Studies , Intervertebral Disc , Retrospective Studies , Soft Tissue Injuries , Spinal Stenosis , Spondylitis , SpondylolisthesisABSTRACT
0.05). Incision size,operating time,blood loss,hospital stay,medical device expenses,postoperative VAS and ODI,clinical outcomes,fusion rates,and complication rates were studied and tested with independent sample t test and x2 test.[Results]The mean follow-up was 19.1 months (range,12~25 months) in group A and 24.6 months (range,9~36 months) in group B.There were statistically significant differences in the incision size,operating time,blood loss,hospital stay and medical device expenses (P0.05).[Conclusion]Unilateral transforaminal lumbar interbody fusion with unilateral pedicle screw fixation has the advantages of small incision,little bleeding,no destruction of the contralateral structure,short operating time or hospital stay,low medical device expenses and good recovery.But the operation indications must be strictly defined.
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OBJECTIVE: The ability to induce segmental lordosis has been reported to be marginal with transforaminal lumbar interbody fusion(TLIF). Therefore, we analyzed the short-term radiological outcomes of TLIF using 8 degrees wedged cages for isthmic sp-ondylolisthesis. METHODS: Twenty-seven patients with isthmic spondyloisthesis who underwent single level TLIF with pedicle screw fixation (PSF) using 8 degrees wedged cages were retrospectively evaluated. Changes in disc height, degree of anterolisthesis, segmental lumbar lordosis, whole lumbar lordosis and L1 axis S1 distance were evaluated using standing lateral radiographs before surgery, at 6 weeks follow-up and at the final follow-up. RESULTS: The mean age of the patients was 49.9 years (range, 38 to 64 years). The affected levels were L4-5 in 17 cases and L5-S1 in 10. There were 18 cases of Grade I isthmic spondylolisthesis and 9 cases of Grade II. At a mean follow-up duration of 9.9 months (range, 6 to 18 months), the disc height (p<0.001) was significantly increased, and the degree of anterolisthesis was significantly reduced (p<0.001). Regarding the sagittal balance, the segmental lumbar lordosis was significantly increased (p=0.01), but other parameters were not significantly changed after surgery. CONCLUSION: TLIF with PSF using 8 degrees wedged cages significantly increased the segmental lumbar lordosis.
Subject(s)
Animals , Humans , Axis, Cervical Vertebra , Follow-Up Studies , Lordosis , Retrospective Studies , SpondylolisthesisABSTRACT
STUDY DESIGN: A retrospective study OBJECTIVES: To evaluate the clinical and radiological results of a transforaminal lumbar interbody fusion for the treatment of non-union after a posterolateral spinal fusion. LITERATURE REVIEW SUMMARY: In the case of nonunion after a posterolateral spinal fusion, the anterior column should be reconstructed. However, due to epidural scarring and fibrosis, the approach to the anterior column by conventional posterior lumbar interbody fusion (PLIF) is difficult. The authors have modified the original transforaminal lumbar interbody fusion (TLIF) developed by Dr. Harms, which offers potential advantages and provides a surgical alternative to the traditional methods. MATERIALS AND METHODS: Between January 2002 and August 2003, 10 cases of TLIF for the treatment of non-unions after a posterolateral spinal fusion were performed. There were 8 male and 2 female cases. The mean age of the patient was 63.3 years, ranging from 53 to 75 years. The levels of the TLIF were the L4-5 and L5-S1 in 9 and 1 cases, respectively. The mean interval between the revision and previous operations was 21.3 months, ranging 12 to 48 months. In the preoperative radiography, bony defect in posterolateral fusion mass, halos around screws and abnormal motions in the stress view were observed. Using the previous midline approach, exposure of the bilateral articular and transverse processes were performed. With a small osteotome, the superior articular process was removed along a line parallel to the superior margins of the pedicular screw head, to allow access to the neural foramen and lateral aspect of the disc space. The TLIF was performed through this space by inserting cages. The loosened screw was replaced by one that was thicker, coupled with a cancellous bone graft in the foramen. RESULTS: The average operation time and blood loss were 224 min. and 727 cc, respectively. Using Kirkaldy-Willis categories, the results were excellent in 1 case, good in 7, fair in 1 and poor in a further 1 case, with 1 case of nonunion was observed postoperatively. CONCLUSIONS: The transforaminal lumbar interbody fusion for the treatment of nonunion after a posterolateral spinal fusion is a reliable and safe technique, which seems to have the merit of less morbidity.
Subject(s)
Female , Humans , Male , Cicatrix , Fibrosis , Head , Radiography , Retrospective Studies , Spinal Fusion , TransplantsABSTRACT
STUDY DESIGN: A retrospective study OBJECTIVES: To evaluate the clinical and radiological results of a transforaminal lumbar interbody fusion for the treatment of non-union after a posterolateral spinal fusion. LITERATURE REVIEW SUMMARY: In the case of nonunion after a posterolateral spinal fusion, the anterior column should be reconstructed. However, due to epidural scarring and fibrosis, the approach to the anterior column by conventional posterior lumbar interbody fusion (PLIF) is difficult. The authors have modified the original transforaminal lumbar interbody fusion (TLIF) developed by Dr. Harms, which offers potential advantages and provides a surgical alternative to the traditional methods. MATERIALS AND METHODS: Between January 2002 and August 2003, 10 cases of TLIF for the treatment of non-unions after a posterolateral spinal fusion were performed. There were 8 male and 2 female cases. The mean age of the patient was 63.3 years, ranging from 53 to 75 years. The levels of the TLIF were the L4-5 and L5-S1 in 9 and 1 cases, respectively. The mean interval between the revision and previous operations was 21.3 months, ranging 12 to 48 months. In the preoperative radiography, bony defect in posterolateral fusion mass, halos around screws and abnormal motions in the stress view were observed. Using the previous midline approach, exposure of the bilateral articular and transverse processes were performed. With a small osteotome, the superior articular process was removed along a line parallel to the superior margins of the pedicular screw head, to allow access to the neural foramen and lateral aspect of the disc space. The TLIF was performed through this space by inserting cages. The loosened screw was replaced by one that was thicker, coupled with a cancellous bone graft in the foramen. RESULTS: The average operation time and blood loss were 224 min. and 727 cc, respectively. Using Kirkaldy-Willis categories, the results were excellent in 1 case, good in 7, fair in 1 and poor in a further 1 case, with 1 case of nonunion was observed postoperatively. CONCLUSIONS: The transforaminal lumbar interbody fusion for the treatment of nonunion after a posterolateral spinal fusion is a reliable and safe technique, which seems to have the merit of less morbidity.