Mini-open Transforaminal Lumbar Interbody Fusion Research Articles

Comparison of mMO-TLIF via Midline Incision Versus MIS-TLIF via Wiltse Approach in Lumbar Degenerative Disease

BackgroundTo compare the clinical and radiological outcomes of modified mini-open transforaminal lumbar interbody fusion (mMO-TLIF) via posterior midline incision for "targeted limited dissection" versus minimal invasive transforaminal lumbar interbody fusion (MIS-TLIF) via Wiltse approach in lumbar degenerative diseases.MethodsA total of 60 consecutive patients in our center from January 2019 to March 2020 were enrolled, including 30 patients who were treated with mMO-TLIF via posterior midline incision and 30 treated with MIS-TLIF through the Wiltse approach. Perioperative parameters were recorded. The questionnaires of Oswestry Disability Index (ODI) and Visual Analogue Score (VAS) were conducted before the operation and after the operation (3 days, 1 week, and 2 years). CT and MRI radiological outcomes were evaluated before the operation and at a 2-year follow-up.ResultsThere were no significant differences in the general data, gender, age, and BMI between the two groups. All patients were successfully operated without intraoperative complications. There were significant differences between the two groups in the operation time (p < 0.001) and intraoperative bleeding (p < 0.05). There was no difference in ODI and VAS scores between groups pre- and post-operatively, but they were both significantly improved compared to those before the operation (p < 0.01). At a 2-year follow-up, the paraspinal muscle atrophy and fat infiltration were increased comparing to pre-operation, but the difference was also not statistically significant (p > 0.05). In addition, both the two groups’ fusion rates were more than 90% at a 2-year follow-up, however, no difference was detected between the two groups.ConclusionmMO-TLIF via midline incision for “targeted limited dissection” could achieve similar clinical and radiological outcomes as MIS-TLIF for lumbar degenerative disease.

Lumbar lordosis restoration by minimally invasive short-segment fusion with anterior column realignment for adult spinal deformity: minimum 2-year follow-up.

The efficacy of anterior column realignment (ACR) remains relatively unclear, possibly because some safety concerns have limited its adoption and extensive evaluation. The authors aimed to study whether a minimally invasive surgery (MIS) triad consisting of ACR, lateral lumbar interbody fusion, and percutaneous pedicle screw fixation in a select group of adult spinal deformity (ASD) patients helps shorten fusion length without compromising clinical and radiographic outcomes over a minimum 2-year follow-up period. A series of 61 ASD patients (mean age 72.8 years) with pelvic incidence (PI) - lumbar lordosis (LL) (PI-LL) mismatch > 10° underwent the short-segment MIS triad (mean fusion length 3.0 levels) as a single-stage operation with a mean operative time and estimated blood loss of 157 minutes and 127 mL, respectively. Exclusion criteria were 1) thoracic scoliosis as the main deformity, 2) thoracolumbar junction kyphosis > 25°, 3) ankylosed facet joints, and 4) previous spinal fusion surgery. Seven patients, who needed fusion to be extended to S1, underwent mini-open transforaminal lumbar interbody fusion at L5-S1. The segmental disc angle at the ACR level more than quintupled, averaging from 2.9° preoperatively to 18.9° at the latest follow-up (p < 0.0001). LL, in turn, nearly doubled from 17.0° to 32.8° (p < 0.0001) and PI-LL decreased by nearly half from 28.8° to 13.2° (p < 0.0001). At the same time, other spinopelvic deformity parameters as well as Oswestry Disability Index (ODI) scores significantly improved. Patients were divided into two groups at the latest postoperative evaluation: 36 patients whose PI-LL improved to < 10° and 25 patients who maintained a PI-LL mismatch > 10°. Binary logistic regression revealed preoperative PI-LL mismatch as the only factor that significantly influenced this dichotomous separation postoperatively. Receiver operating characteristic curve analysis identified the critical preoperative mismatch of 26.4° with 68% sensitivity and 84% specificity. Despite this different radiographic consequence, the two groups had an equally successful clinical outcome with no significant difference in ODI scores. As long as the ASD characteristics are consistent with the authors' exclusion criteria, the short-segment MIS triad served as an excellent surgical option in the patients with preoperative PI-LL mismatch < 26.4°, but the technique also worked well even in those with a mismatch > 26.4°, although ideal spinopelvic alignment targets were not necessarily achieved in these patients.

A novel mini-open transforaminal lumbar interbody fusion for lumbar degenerative diseases: technical note and preliminary results

BackgroundTransforaminal lumbar interbody fusion (TLIF) is an effective and popular surgical procedure for the management of various spinal pathologies, especially degenerative diseases. Surgeons have been pursuing minimally invasive technology as soon as TLIF was appeared. Currently, TLIF can be performed with transforaminal approaches by open surgery, minimally invasive surgery or percutaneous endoscope. We provide a detailed description of a new modified open TLIF with percutaneous pedicle screws, which we refer to as mini-open TLIF. The objective of this study was to present feasibility of this procedure and the preliminary results.MethodsThe study is a prospective study. From January 2021 to March 2022, 96 patients (43 males and 53 females) with neurological symptoms due to degenerative lumbar spine diseases were enrolled. Operation time, blood loss, ambulatory time, hematocrit and complications were recorded during perioperative period. Clinical symptoms were evaluated 1 week, 3 months and 12 months after surgery. Visual analogue scale (VAS) scores for lower back pain and leg pain and Oswestry disability index (ODI) were assessed. Magnetic resonance imaging was performed preoperatively and 12 months postoperatively to emulate cross-sectional area of paraspinal muscles. The lumbar interbody fusion rate was evaluated by CT scanning.ResultsThe mean operation time of single level was 112.6 min, and the mean operation time of multilevel was 140.1 min. Intraoperative blood loss of single level was 64.5 ml and was 116.3 ml of multilevel. The VAS and ODI scores before and after surgery were significantly different (P < 0.0001) and reached minimal clinically important difference. Atrophy rate of paraspinal muscles was 2.5% for symptomatic side and 1.2% for asymptomatic side. The cross-sectional area before and after the operation and atrophy rate had no statistically significant difference (P > 0.05).ConclusionMini-open TLIF is effective and feasible for the treatment of lumbar degenerative diseases especially in multilevel disease, with minor damage to muscle and shorter operation time.Trial registration: This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of the Second Affiliated Hospital of Soochow University (No. JD-LK2023045-I01).

How I do it: mini invasive transforaminal lumbar interbody fusion.

Minimally invasive approaches for lumbar fusion are aimed at reducing soft tissue injury in order to minimize surgical morbidity and facilitate recovery. Applied to lumbar fusion, such an approach is described as a mini-open transforaminal lumbar interbody fusion (TLIF). Important anatomical landmarks are reviewed. Indications, advantages, and limitations are discussed, and a step-by-step description of the procedure is presented. Decompression, fixation, and bone grafting can be achieved efficiently through this approach with lesser blood loss, shorter hospital stay, reduced rate of general complications, and infections as well as a lower readmission rate. The mini-open TLIF technique, as presented here, is a safe and efficient procedure to achieve lumbar fusion with a reduced rate of complications related to surgery.

Clinical and Radiological Outcomes of Modified Mini-Open and Open Transforaminal Lumbar Interbody Fusion: A Comparative Study.

Study DesignRetrospective cohort study.PurposeTo compare the clinical and radiological outcomes of modified mini-open transforaminal lumbar interbody fusion (modMOTLIF) and open TLIF (OTLIF).Overview of LiteratureMinimally invasive transforaminal lumbar interbody fusion (MTLIF) is associated with less blood loss, shorter hospital stay, and less pain. However, it has concerns like increased radiation exposure, steep learning curve, and instrumentation cost. We modified the MTLIF technique by direct freehand insertion of pedicle screws using stab incisions without tubular retractors.MethodsThe study included 24 patients in the modMOTLIF group and 27 patients in the OTLIF group. The average follow-up period was 25.6 months. Clinical outcomes were measured using Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores. Serial X-rays were acquired at 1, 3, 6, 12, and 24 months to assess the union and presence of instability. We also compared blood loss and length of hospital stay in both groups.ResultsAll patients showed progressive improvement in VAS and ODI scores. No differences were observed in the preoperative and postoperative ODI and VAS leg scores between the groups. The immediate postoperative VAS back score was significantly higher in the OTLIF group than in the modMOTLIF group; however, no difference was observed at 1 and 2 years. Radiological analysis showed nonunion in one and two patients in the OTLIF and modMOTLIF groups, respectively. The average blood loss was 63 mL in the mod-MOTLIF group and 254 mL in the OTLIF group. The mean hospital stay was 3 days for the modMOTLIF group and 5 days for the OTLIF group.ConclusionsmodMOTLIF was associated with reduced blood loss and shorter hospital stay compared with OTLIF. No significant differences were observed in the clinical and radiological outcomes between the groups after 2 years despite reduced back pain in the immediate postoperative period in patients who underwent modMOTLIF.

Comparison of Clinical and Radiologic Results of Mini-Open Transforaminal Lumbar Interbody Fusion and Extreme Lateral Interbody Fusion Indirect Decompression for Degenerative Lumbar Spondylolisthesis.

Study DesignRetrospective study.PurposeIn this study, we compared the postoperative outcomes of extreme lateral interbody fusion (XLIF) indirect decompression with that of mini-open transforaminal lumbar interbody fusion (TLIF) in patients with lumbar degenerative spondylolisthesis.Overview of LiteratureThere are very few reports examining postoperative results of XLIF and minimally invasive TLIF for degenerative lumbar spondylolisthesis, and no reports comparing XLIF and mini-open TLIF.MethodsForty patients who underwent 1-level spinal fusion, either by XLIF indirect decompression (X group, 20 patients) or by mini-open TLIF (T group, 20 patients), for treatment of lumbar degenerative spondylolisthesis were included in this study. Invasiveness of surgery was evaluated on the basis of surgery time, blood loss, hospitalization period, and perioperative complications. The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ), disc angle (DA), disc height (DH), and slipping length (SL) were evaluated before surgery, immediately after surgery, and at 12 months after surgery. Cross-sectional spinal canal area (CSA) was also measured before surgery and at 1 month after surgery.ResultsThere was no significant difference between the groups in terms of surgery time or hospitalization period; however, X group showed a significant decrease in blood loss (p<0.001). Serious complications were not observed in either group. In clinical assessment, no significant differences were observed between the groups with regard to the JOABPEQ results. The change in DH at 12 months after surgery increased significantly in the X group (p<0.05), and the changes in DA and SL were not significantly different between the two groups. The change in CSA was significantly greater in the T group (p<0.001).ConclusionsPostoperative clinical results were equally favorable for both procedures; however, in comparison with mini-open TLIF, less blood loss and greater correction of DH were observed in XLIF.

The unfeasible made feasible: lumbar minimally invasive hybrid stabilization with dynamic rod and mini-open transforaminal lumbar interbody fusion.

Posterior dynamic stabilization of the lumbar spine is spreading as a viable alternative to spinal fusion, aiming to achieve an equally satisfactory clinical outcome without making the spine completely rigid. We describe the feasibility of a minimally invasive surgical technique used to implant a hybrid system and perform a mini-open (m-open) transforaminal lumbar interbody fusion (TLIF) in patients suffering from degenerative spondylolistesis and adjacent level's degenerative disc disease (DDD). Three patients (2 females), suffering from degenerative spondylolistesis and adjacent level's DDD, underwent two-level hybrid stabilization combining a rigid, circumferential fusion (with m-open TLIF) at the level involved by spondylolistesis and a dynamic stabilization at the adjacent one. Screws, hybrid rods as well as interbody cages were introduced using a simple minimally invasive technique. Clinical and radiological evaluation was performed pre- and postoperatively, and at 3, 6 and 12 months, respectively, using the Visual Analogue Scale and the Oswestry Disability Index questionnaire. Mean VAS and ODI score reduced from 8.3, preoperatively, to 5 and from 72.66 to 43.98, respectively. No surgery-related complications were observed and the mean postoperative hospitalization was 2.5 days. Postoperative and follow-up flexion-extension X-rays showed persisting motion at dynamically stabilized levels. Follow-up CT imaging confirmed interbody fusion at TLIF levels in all patients. Dynamic and hybrid stabilizations of the lumbar spine are typically performed using open surgery. This study reports the feasibility of a hybrid stabilization with m-open TLIF performed using a minimally invasive technique.

Restoration of Thoracolumbar Spine Stability and Alignment in Elderly Patients Using Minimally Invasive Spine Surgery (MISS). A Safe and Feasible Option in Degenerative and Traumatic Spine Diseases.

Minimally invasive spine surgery (MISS), including percutaneous pedicle-screw fixation (PPSF), mini-open transforaminal lumbar interbody fusion (m-open TLIF), vertebroplasty, and stentoplasty, allows the preservation of neurological function and the restoration of spine stability, while reducing associated risks and complications. This study aimed to analyze the safety and efficacy of MISS in elderly patients suffering from degenerative or traumatic thoracolumbar diseases. Forty-five patients (28 females), with a mean age of 73 years (range 65-89), suffering from osteoporotic vertebral fractures (24), degenerative spondylolisthesis (15), and lumbar canal stenosis with instability and/or de novo scoliosis (6) were included.Twenty-one patients underwent PPSF and m-open TLIF. The remaining patients received PPSF without interbody fusion, and in six of these fenestrated screws were used for vertebral body cement augmentation.Functional evaluation was obtained with a visual analog scale (VAS) and the Oswestry Disability Index (ODI) pre- and postoperatively. Preoperative imaging included X-rays, computed tomography (CT), and magnetic resonance imaging (MRI). Patients were followed-up with X-rays, and a CT scan was also obtained at the last follow-up. Follow-up ranged from 6 to 59 months (mean 28 months). Follow-up CT scan documented intersomatic fusion in only 14 % of patients treated with m-open TLIF. Despite the high incidence of non-union, mean VAS and ODI scores showed a significant improvement, with a reduction of mean VAS from 9 to 4 and a reduction of mean ODI from 76.33 to 38.15 %. Only three patients developed postoperative complications. No patients showed neurological deficits.Minimally invasive spine surgery for degenerative and traumatic spinal diseases is a safe and effective treatment also in elderly patients.

Modified Mini-open Transforaminal Lumbar Interbody Fusion: Description of Surgical Technique and Assessment of Free-hand Pedicle Screw Insertion.

Study Design.Retrospective case series.Objective.To describe a modified technique for mini-open transforaminal lumbar interbody fusion (TLIF) that improves visualization for decompression, fusion, and freehand pedicle screw insertion. Accuracy of freehand pedicle screw placement with this technique was assessed.Summary of Background Data.Mini-open TLIF is a minimally invasive technique that allows limited visualization of the bone and neural anatomy via an expandable tubular retractor inserted through the Wiltse plane. No significant modification that of this technique has been described in detail.Methods.In this study, 92 consecutive patients underwent one-level modified mini-open TLIF (MOTLIF). MOTLIF modifications consisted of (i) transmuscular dissection through the multifidus muscle rather than intermuscular dissection in the Wiltse plane; (ii) microsurgical detachment of multifidus from the facet rather than muscle dilation; (iii) en bloc total facetectomy (unilateral or bilateral, as needed for decompression); (iv) facet autograft used for interbody fusion; and (v) solid pedicle screws placed bilaterally by a freehand technique under direct vision.Results.The mean age was 53 years. Mean follow-up was 35 months (minimum 2 yrs). By 6 months, mean Visual Analog Scale for back and leg pain had improved from 51 to 19 and from 58 to 17, respectively, and mean Oswestry Disability Index (ODI) improved from 53 to 16. These improvements persisted at 2 years. Solid fusion, defined by computed tomography at 1 year, was achieved in 88.1%, whereas satisfactory fusion was achieved in 95.2% of patients. Pedicle screws were accurately placed in 335 of 336 imaged pedicles (pedicle breach grades: 91.1% grade 1; 8.6% grade 2; and 0.3% grade 3). Mean fluoroscopy time was 29.3 seconds.Conclusion.MOTLIF is a safe and effective minimally invasive technique with a high fusion rate. It allows accurate pedicle screw placement by a freehand technique. By eliminating bi-planar fluoroscopy, it helps reduce radiation exposure. This is the largest published report of mini-open TLIF to date.Level of Evidence: 4

Analysis of surgeon experience and impact of comorbidities on early discharge after mini-open transforaminal lumbar interbody fusion

Background: Mini-open transforaminal lumbar interbody fusion (TLIF) has emerged as an alternative to open lumbar fusion. Currently, there is a limited amount of literature concerning the learning curve and perioperative variables of mini-open TLIF despite literature suggesting its overall advantage over open procedures. The objectives of this study were to evaluate the learning curve associated with mini-open TLIF and to identify factors affecting length of stay (LOS). Methods: Retrospective review of one surgeon’s first 100 mini-open TLIF cases was performed to evaluate operative time, LOS, estimated blood loss (EBL), Oswestry Disability Index (ODI), visual analog pain scores (VAS), and fusion status. Operative time and LOS data were used to determine a proficiency point. Additional patient factors were collected and their impact on LOS was determined. Results: Operative time was found to be significantly less after 21 patients and LOS shorter after 22 patients. No significant differences were found when the first 22 patients were compared to the last 78 patients for ODI, VAS, and fusion status. Factors associated with decreased LOS include shorter operative time, lower EBL, later point on the learning curve of the surgeon, and patient factors including lower body mass index, being married or living with a significant other, and having a prior lumbar surgery. Conclusions: A significant learning curve is associated with mini-open TLIF. Similar follow-up outcomes suggest satisfactory outcomes even during the learning curve period.

A Preliminary Report on the CO2 Laser for Lumbar Fusion: Safety, Efficacy and Technical Considerations.

The purpose of this study was to evaluate potential technical advantages of the CO2 laser technology in mini-open transforaminal lumbar interbody fusion (TLIF) surgeries and report our preliminary clinical data on the safety and clinical outcomes. There is currently no literature discussing the recently redeveloped CO2 laser technology application for lumbar fusion. Safety and clinical outcomes were compared between two groups: 24 patients that underwent CO2 laser-assisted one-level TLIF surgeries and 30 patients that underwent standard one-level TLIF surgeries without the laser.There were no neural thermal injuries or other intraoperative laser-related complications encountered in this cohort of patients. At a mean follow-up of 17.4 months, significantly reduced lower back pain scores (P=0.013) were reported in the laser-assisted patient group compared to a standard fusion patient group. Lower extremity radicular pain intensity scores were similar in both groups. Laser-assisted TLIF surgeries showed a tendency (P = 0.07) of shorter operative times that was not statistically significant.Based on this preliminary clinical report, the safety of the CO2 laser device for lumbar fusion surgeries was assessed. There were no neural thermal injuries or other intraoperative laser-related complications encountered in this cohort of patients. Further investigation of CO2 laser-assisted lumbar fusion procedures is warranted in order to evaluate its effect on clinical outcomes.

Transforaminal Lumbar Interbody Fusion for Lumbar Degenerative Disorders: Mini-open TLIF and Corrective TLIF.

Minimally invasive transforaminal lumbar interbody fusion (TLIF) as a short fusion is widely accepted among the spine surgeons. However in the long fusion for degenerative kyphoscoliosis, corrective spinal fixation by an open method is thought to be frequently selected. Our objective is to study whether the mini-open TLIF and corrective TLIF contribute to the improvement of the spinal segmental and global alignment. We divided the patients who performed lumbar fixation surgery into three groups. Group 1 (G1) consisted of mini-open TLIF procedures without complication. Group 2 (G2) consisted of corrective TLIF without complication. Group 3 (G3) consisted of corrective TLIF with instrumentation-related complication postoperatively. In all groups, the lumbar lordosis (LL) highly correlated with developing surgical complications. LL significantly changed postoperatively in all groups, but was not corrected in the normal range in G3. There were statistically significant differences in preoperative and postoperative LL and mean difference between the pelvic incidence (PI) and LL between G3 and other groups. The most important thing not to cause the instrumentation-related failure is proper correction of the sagittal balance. In the cases with minimal sagittal imbalance with or without coronal imbalance, short fusion by mini-open TLIF or long fusion by corrective TLIF contributes to good clinical results if the lesion is short or easily correctable. However, if the patients have apparent sagittal imbalance with or without coronal imbalance, we should perform proper correction of the sagittal spinal alignment introducing various technologies.

Multilevel mini-open TLIFs and percutaneous pedicle screw fixation: description of a simple technical nuance used to increase intraoperative safety and improve workflow. Tips and tricks and review of the literature.

We describe a technical variation used to enhance intraoperative safety and efficiency in multilevel percutaneous pedicle screw fixation (PPSFs) and mini-open transforaminal lumbar interbody fusion (m-TLIFs). A review of the literature on percutaneous screw insertion techniques and related pitfalls is presented. PPSFs and m-TLIFs are increasingly used techniques in multilevel lumbar degenerative disease. Facetectomy and TLIF are usually performed before inserting ipsilateral pedicle screws. Such techniques can cause unintended violation of the pedicle and injure the dura or neural structures, particularly in multilevel cases. A literature review revealed a lack of intraoperative and fluoroscopic images detailing the technique for multilevel PPSF and m-TLIF(s) performed through tubular, expandable retractors. Thirteen patients with two- to four-level disease underwent multilevel PPSF and m-TLIF (one to four levels). The Kirschner Cage Screw (KCS) technique, consisting of early insertion of K-wires in all pedicles followed by facetectomy and m-TLIF(s) and, finally, screw insertion, was used in order to minimize the risk of dural/neural injuries. Neither CSF (cerebrospinal fluid) leaks nor nerve root injuries nor technique-related complications were encountered with a follow-up ranging from 7 to 38 months (mean 23.6). In conclusion, the KCS technique allows safe identification of the pedicles without opening the canal during m-TLIF(s). Moreover, by visualizing the K-wires inside the retractor, the surgeon can check the pedicle position during facetectomy, and screws can be introduced with a minimal risk of neural or dural injuries. We believe that the proposed technique increases the safety and ease of the procedure, particularly in multilevel cases.

Nerve root anomalies: implications for transforaminal lumbar interbody fusion surgery and a review of the Neidre and Macnab classification system

Lumbar nerve root anomalies are uncommon phenomena that must be recognized to avoid neural injury during surgery. The authors describe 2 cases of nerve root anomalies encountered during mini-open transforaminal lumbar interbody fusion (TLIF) surgery. One anomaly was a confluent variant not previously classified; the authors suggest that this variant be reflected in an amendment to the Neidre and Macnab classification system. They also propose strategies for identifying these anomalies and avoiding injury to anomalous nerve roots during TLIF surgery. Case 1 involved a 68-year-old woman with a 2-year history of neurogenic claudication. An MR image demonstrated L4-5 stenosis and spondylolisthesis and an L-4 nerve root that appeared unusually low in the neural foramen. During a mini-open TLIF procedure, a nerve root anomaly was seen. Six months after surgery this patient was free of neurogenic claudication. Case 2 involved a 60-year-old woman with a 1-year history of left L-4 radicular pain. Both MR and CT images demonstrated severe left L-4 foraminal stenosis and focal scoliosis. Before surgery, a nerve root anomaly was not detected, but during a unilateral mini-open TLIF procedure, a confluent nerve root was identified. Two years after surgery, this patient was free of radicular pain.

Mini-open posterior approach for adult deformity correction

Minimally invasive surgical (MIS) approaches are gaining popularity in many surgical fields. Potential advantages include reduced blood loss, shorter length of stay, and less soft-tissue trauma. Potential disadvantages include inadequate deformity correction, increased fluoroscopy, longer operative times, and decreased posterolateral fusion surface area exposure. This video demonstrates the key steps in our mini-open transforaminal lumbar interbody fusion (TLIF) using an expandable tubular retractor, placement of cannulated pedicle instrumentation, and subsequent deformity correction. The video demonstrates positioning, surgical opening through a midline incision, a bilateral Wiltse plane tubular approach for the TLIF, placement of bilateral cannulated pedicle screws, and deformity correction. The video can be found here: http://youtu.be/Fpccr4MlLMU.

Intraoperative navigation assisted placement of percutaneous pedicle screws

Minimally invasive surgical (MIS) approaches are gaining popularity in many surgical fields. Potential advantages include reduced blood loss, shorter length of stay, and less soft-tissue trauma. Potential disadvantages include inadequate deformity correction, increased fluoroscopy, longer operative times, and decreased posterolateral fusion surface area exposure. This video demonstrates the key steps in our mini-open transforaminal lumbar interbody fusion (TLIF) using an expandable tubular retractor, placement of cannulated pedicle instrumentation, and subsequent deformity correction. The video demonstrates positioning, surgical opening through a midline incision, a bilateral Wiltse plane tubular approach for the TLIF, placement of bilateral cannulated pedicle screws, and deformity correction. The video can be found here: http://youtu.be/Jj7w4i2DTMQ.

Clinical outcomes of minimally invasive versus open approach for one-level transforaminal lumbar interbody fusion at the 3- to 4-year follow-up

Supporters of minimally invasive approaches for transforaminal lumbar interbody fusion (TLIF) have reported short-term advantages associated with a reduced soft tissue trauma. Nevertheless, mid- and long-term outcomes and specifically those involving physical activities have not been adequately studied. The aim of this study was to compare the clinical outcomes of mini-open versus classic open surgery for one-level TLIF, with an individualized evaluation of the variables used for the clinical assessment. A prospective cohort study was conducted of 41 individuals with degenerative disc disease who underwent a one-level TLIF from January 2007 to June 2008. Patients were randomized into two groups depending on the type of surgery performed: classic open (CL-TLIF) group and mini-open approach (MO-TLIF) group. The visual analog scale (VAS), North American Spine Society (NASS) Low Back Pain Outcome instrument, Oswestry Disability Index (ODI) and the Short Form 36 Health Survey (SF-36) were used for clinical assessment in a minimum 3-year follow-up (36-54 months). Patients of the MO-TLIF group presented lower rates of lumbar (p = 0.194) and sciatic pain (p = 0.427) and performed better in daily life activities, especially in those requiring mild efforts: lifting slight weights (p = 0.081), standing (p = 0.097), carrying groceries (p = 0.033), walking (p = 0.069) and dressing (p = 0.074). Nevertheless, the global scores of the clinical questionnaires showed no statistical differences between the CL-TLIF and the MO-TLIF groups. Despite an improved functional status of MO-TLIF patients in the short term, the clinical outcomes of mini-open TLIF at the 3- to 4-year follow-up showed no clinically relevant differences to those obtained with open TLIF.

Transforaminal Lumbar Interbody Fusion: Comparison between Open and Mini-Open Approaches with Two Years Follow-Up

Transforaminal lumbar interbody fusion (TLIF) is an efficient technique which can achieve a fusion rate of up to 90%. Minimally invasive approaches have become increasingly popular because they appear to minimize iatrogenic soft tissue and muscle injury. As minimally invasive TLIF gains popularity, its effectiveness compared with open TLIF has yet to be established. A retrospective study was performed with the aim to compare long-term outcomes of patients who underwent mini-open TLIF with those who underwent open TLIF. This is a retrospective review of prospectively collected data. Between 2005 and 2008, 100 patients underwent TLIF for low-grade spondylolisthesis or degenerative disc disease; 60 underwent open TLIF and 40 underwent mini-open TLIF. The mean age in each group was 48 years, and there were no statistically significant differences between the groups. Data were collected perioperatively. Pain and functional disability were measured using visual analogue scale (VAS) and Oswestry disability index (ODI) at 3 months, 6 months, 1 year, and 2 years. In addition, the fusion was evaluated at 1 year on a computerized tomography (CT) scan. The mean VAS improved from 7.3 to 3.8 for back pain and from 7 to 2.7 for leg pain and the ODI decreased from 60 to 30% at 2 years postoperatively. The fusion rate at 1 year was 98%. There were no statistical differences for the clinical and radiological outcomes between the groups. The mean operative time was 186 minutes in the open group and 170 minutes in the mini-open group (p < 0.05) and the mean blood loss was 486 mL in the open group and 148 mL in the mini-open group (p < 0.01). The mini-open TLIF for symptomatic low-grade spondylolisthesis and degenerative disc disease is an effective option that achieves the same clinical and radiological outcomes at a minimum 2-year follow-up and reduces perioperative morbidity.

Mini-open and Conventional-open Transforaminal Lumbar Interbody Fusion Augmented by Pedicle Screw Fixation: Comparisonal Result of Clinical, Perioperative Parametric, Functional and Radiological Assessments

Background: Despite numerous reports on mini-open transforaminal lumbar interbody fusion (TLIF), there exists a few studies to compare directly mini-open TLIF and conventional-open TLIF procedures. This study evaluated the usefulness and safety of mini-open TLIF for degenerative lumbar diseases and instabilities. Material and methods: Sixty-eight patients underwent TLIF with pedicle screw fixation for degenerative disc disease or spondylolisthesis with more than 12 months follow-up; 22 patients underwent mini-open TLIF and 46 patients underwent conventional-open TLIF. Data of incision, perioperative parameters, complications, fusion rate, and clinical data were reviewed. Results: The length of incision was shorter in mini-open TLIF group (p=0.04), but satisfaction rate of incision was not statistically different (p=0.18). The VAS and mODI were significant lower in mini-open TLIF (p=0.037, 0.031, respectively) at postoperative 7 days. Less estimated blood loss and less change in hemoglobin and blood pressure during operation was observed in mini-open TLIF group than conventional-open TLIF group. The fusion rate was also not statistically different. The complication including the pedicle screw fracture, bony spur, adjacent level instability was observed in 14% in the mini-open TLIF group and 10% in the conventional-open TLIF group (p=0.63). Conclusion: The mini-open TLIF with pedicle screw fixation provides excellent clinical results and may be an operation of choice for lumbar spinal fusion. The long-term clinical, functional and radiological results were similar in the mini-open and conventional-open TLIF. But, the mini-open TLIF is a viable alternative to the conventional-open TLIF with advantage of lesser blood loss, less change of hemoglobin and blood pressure, shorter incision, and lesser postoperative pain.

The accuracy of 3D image navigation with a cutaneously fixed dynamic reference frame in minimally invasive transforaminal lumbar interbody fusion

Objective: In contrast to preoperative image-based 3D navigation systems, which require surgeon-dependent registration, an intraoperative cone-beam computed tomography (cb-CT) image-based 3D navigation system allows automatic registration during the acquisition of 3D images intraoperatively. Thus, the need for spinal exposure for point matching is obviated, making a cb-CT image-based navigation system ideal for use in minimally invasive spinal procedures. Conventionally, the dynamic reference frame (DRF) is mounted to an adjacent spinous process or iliac bone through a separate incision. However, the close proximity of the DRF to the surgical area may result in its interfering with the surgical procedure or causing streak artifacts on the navigation images. Cutaneous placement of the DRF overlying the sacral hiatus is one possible solution to these problems, but such a placement does not provide a solid bony fixation point and is distant from the surgical area, both of which factors may hinder the accuracy of the navigation. The purpose of this study was to evaluate the accuracy of a novel idea for DRF placement in a series of mini-open transforaminal lumbar interbody fusion (TLIF) procedures performed with intraoperative cb-CT image-based 3D navigation.Methods: From June 2009 to December 2009, 20 patients underwent mini-open TLIF for a total 82 pedicle screws placed in the lumbar spine with cutaneous placement of the DRF overlying the sacral hiatus. The pedicle screws were inserted under navigational guidance using cb-CT data acquired intraoperatively with a Medtronic O-arm. Screw positions were subsequently checked with a final intraoperative cb-CT scan. Nineteen patients underwent single-level fusion (8 at L4–5, 6 at L5–S1, 4 at L3–4, and 1 at L2–3) and one patient underwent two-level fusion (from L3–5).Results: There were 4 (4.9%) pedicle perforations greater than 2 mm out of the 82 pedicle screw insertions in the 20 patients. Two of these breached screws were repositioned and confirmed to be in place with a final intraoperative cb-CT. There were no complications of neural injury associated with these perforations.Conclusion: A cutaneously mounted DRF overlying the sacral hiatus provides accuracy in intraoperative 3D image guided navigation for mini-open TLIF that is comparable to that obtained in other reported series using a fixed bony attachment point for the DRF.