Midline Lumbar Fusion Research Articles

The accuracy of cortical bone trajectory screw placement guided by spinous process clamp hardware in lumbar spinal surgery: a retrospective study

This study aimed to assess the accuracy of cortical bone trajectory (CBT) screws placement guided by a spinous process clamp (SPC) guide. A total of 32 patients who received single-level midline lumbar fusion (MIDLF) surgery between June 2019 and January 2020 were retrospectively analyzed and divided into free-hand (FH) and SPC-guided groups according to the surgical approach. In the FH group, CBT screws was implanted with the assistance of fluoroscopy, while in the SPC group, CBT screws was implanted using the SPC navigator hardwire. A total of 128 screws were assessed in this study, with higher rates of clinically acceptable screw placement (grades A and B) and grade A screws in the SPC group than in the FH guide group (92.2% vs. 79.7%, P = 0.042 and 54.7% vs. 35.9%, P = 0.033, respectively). Misplacement screws (grades C, D, and E) occurred more often in the FH group than in the SPC guide group (20.3% vs. 7.8%, P = 0.042). The incidence of proximal facet joint violation (FJV) was higher in the FH group than in the SPC group (15.6% vs. 3.1%, P = 0.030). The radiation dose and time in the SPC guide group were comparable to those in the FH group (P = 0.063 and P = 0.078). The average operative time was significantly longer in the SPC guide group than in the FH group (267.8 ± 45.5 min vs. 210.9 ± 44.5 min, P = 0.001). Other clinical parameters, such as the average bone mineral density (BMD), intraoperative blood loss, and postoperative hospital stay, were not significantly different. Oswestry disability index (ODI) and back pain visual analogue scale (VAS) scores were significantly improved in both groups compared with preoperatively. SPC guided screw placement was more accurate than the fluoroscopy-assisted FH technique for single-level MIDLF at L4/5. Patients undergoing SPC-guided screw placement can achieve similar clinical outcomes as the fluoroscopy-assisted FH technique.

Midline Lumbar Fusion Versus Posterior Lumbar Interbody Fusion Involving L5-S1 For Degenerative Lumbar Diseases: A Comparative Study.

A retrospective cohort study to evaluate the efficacy and safety of midline lumbar fusion (MIDLF) for lumbosacral fusion compared to posterior lumbar interbody fusion (PLIF). Patients who had undergone posterior lumbosacral fusion surgery were divided into a MIDLF group (n=37) and a PLIF group (n=42). The follow-up time was at least 12months. The operation data, recovery condition, complications, clinical outcomes, and status of implants and fusion were compared between the 2 groups. The MIDLF group experienced significantly less blood loss, lower postoperative creatine kinase levels and total drainage volume, earlier time to ambulation, and less hospital stay times after surgery compared to the PLIF group (P<0.05). The mean postoperative back pain visual analog scale scores in the MIDLF group were significantly lower than the PLIF group (P<0.05). The improvement in Oswestry Disability Index scores during 3-month follow-up displayed a significant difference between the 2 groups (P < 0.05). The fusion rate tended to be higher in the MIDLF group; however, the difference was not significant (P > 0.05). There was no significant difference in respect to screw loosening and cage subsidence rate. There were 2 cases of complications both occurring in the PLIF group. MIDLF is safe and effective for lumbosacral fusion and in line with the concept of enhanced recovery after surgery.

Radiological and clinical outcomes of midline lumbar fusion on sagittal lumbar-pelvic parameters for degenerative lumbar diseases.

Improving the sagittal lumbar-pelvic parameters after fusion surgery is important for improving clinical outcomes. The impact of midline lumbar fusion (MIDLF) on sagittal lumbar-pelvic alignment for the management of degenerative lumbar diseases is still unknown. To analyze the effects of short-segment MIDLF and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) on sagittal lumbar-pelvic parameters. We retrospectively analyzed 63 patients with degenerative lumbar diseases who underwent single-segment MIDLF or MIS-TLIF. The imaging data of patients were collected before surgery and at the final follow-up. The radiological sagittal parameters included the lumbar lordosis (LL), lower LL, L4 slope (L4S), L5 slope (L5S), L5 incidence (L5I), L1 axis and S1 distance (LASD), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and PI-LL mismatch (PI-LL). Additionally, the clinical outcomes, including lower back and leg pain visual analog scale (VAS) and Oswestry disability index (ODI) scores, were also analyzed. In both groups, LL and Lower LL significantly increased, while L5I and LASD significantly decreased at the final follow-up compared to that recorded prior to operation (P < 0.05). In the MIDLF group, L4S significantly decreased compared to that recorded prior to operation (P < 0.05), while the mean SS significantly increased and the PT significantly decreased compared to that recorded prior to operation (P < 0.05). In the MIS-TLIF group, SS slightly increased and the mean PT value decreased compared to that recorded prior to operation, but without a statistically significant difference (P > 0.05). However, the PI-LL in both groups was significantly reduced compared to that recorded prior to operation (P < 0.05). There was no significant difference in the sagittal lumbar-pelvic parameters between the two groups prior to operation and at the final follow-up (P > 0.05). In addition, the change in sagittal lumbar-pelvic parameters did not differ significantly, except for ΔLASD within the two groups (P > 0.05). The mean lower back and leg pain VAS and ODI scores in both groups were significantly improved three months after surgery and at the final follow-up. Though the mean ODI score in the MIDLF group three months after surgery was slightly higher than that in the MIS-TLIF group, there was no significant difference between the two groups at the final follow-up. Short-segment MIDLF and MIS-TLIF can equally improve sagittal lumbar parameters such as LL, Lower LL, L5I, and LASD in the treatment of lumbar degenerative diseases. However, MIDLF had a larger impact on pelvic parameters than MIS-TLIF.

Effectiveness of midline lumbar fusion with cortical bone trajectory screw fixation for degenerative lumbar spine disease in geriatric patients over 80 years old: a single-center, one-decade experience

Objective: We aimed to retrospectively analyze clinical and surgical outcomes following posterior lumbar interbody fusion with concomitant pedicle screw fixation, midline lumbar fusion, and decompressive laminectomy in patients aged 80 years or older with degenerative lumbar spine disease.Methods: The study group comprised 94 patients aged 80 years or older who received degenerative lumbar spinal surgery at our spine center from January 2011 to December 2020. Among them, 28 patients underwent decompressive laminectomy, 19 underwent posterior lumbar interbody fusion with pedicle screw fixation, and the remaining 47 underwent midline lumbar fusion.Results: No significant intergroup differences were found regarding age, sex ratio, follow-up duration, and surgical level. The visual analog scale for lower back pain on postoperative day 7 was significantly different among the groups (P&lt;0.05). The Oswestry disability index was significantly different among the groups after 1 week of follow-up (P&lt;0.05). The estimated blood loss and operation time also showed significant differences among the groups (P&lt;0.05). There was a statistically significant difference among the groups in postoperative morbidity (P&lt;0.05).Conclusion: Although the clinical outcomes were not significantly different among the three groups, perioperative morbidity was more favorable in the decompression and midline lumbar fusion groups. Therefore, we suggest that midline lumbar fusion is not inferior to posterior lumbar interbody fusion with pedicle screw fixation, if there is a need for fusion in elderly patients over 80 years of age.

Effects of cortical bone trajectory screw in adjacent-segment disease after posterior lumbar interbody fusion

Objective: To investigate the effect of the cortical bone trajectory (CBT) screw fixation combined with midline lumbar fusion (MIDLF) for adjacent spondylopathy after posterior lumbar interbody fusion. Methods: A retrospective analysis was conducted in 16 patients, including 9 males and 7 females, with a mean age of (68±6) years, who underwent revision surgery for adjacent spondylopathy after posterior lumbar fusion surgery using CBT combined with MIDLF technology in Sir Run Run Shaw Hospital, Zhejiang University from May 2013 to August 2019. The reasons for revision were radiculalgia in 4 cases, intermittent claudication in 10 cases and protrusive dissociate in 2 cases. Eleven cases had 1 segment fused in the first operation, while the other 5 cases received fusion in 2 segments. The average interval time between the first operation and the revision operation was (7.5±2.0) years. For the levels underwent revision, 1 case was L2/3, 6 cases were L3/4, 7 cases were L4/5 and 2 cases were L5/S1. Before the operation, all the patients took X-rays scans of the thoracic and lumbar spine. CT and MRI scans were also performed. The operation time, intraoperative bleeding, surgical complications, visual analog scale (VAS) of low back and leg pain before the operation and at each follow-up were all recorded. Oswestry disability index (ODI) questionnaire was used to evaluate the functional improvement of patients after the operation. Results: All operations were completed successfully. The operation time was 120-240 (170±30) mins, intraoperative bleeding was 100-280 (220±45) ml. One case had a slight split in the isthmus, and the screw was inserted smoothly after adjusting the insertion point. In one case, the cerebrospinal fluid leaked during the operation and was successfully treated with conservative methods including no pillow supine treatment and strengthened anti-infection. The average follow-up time was of (19.5±1.3) months. The VAS of low back pain was 2.9±1.7 before the operation and it was 1.8±0.5 at the last follow-up, and the difference was statistically significant (P<0.01). The VAS of leg pain was 5.9±1.5 before the operation and it was 1.5±0.4 at the last the follow-up (P<0.01). The ODI score was 34.5±3.2 preoperatively and it decreased to 12.6±4.2 at the last follow-up, the difference was statistically significant (P<0.01). Conclusion: CBT technique combined with MIDLF for the adjacent-segment disease after posterior lumbar interbody fusion is minimally invasive and convenient, with good clinical effects. This technique can be used as an option for the revision of adjacent spondylopathy.

Long-Term Outcome After Midline Lumbar Fusion for the Treatment of Lumbar Spine Instability Due to Degenerative Disease

Midline lumbar fusion (MIDLF) is one promising new surgical technique that has been developed to minimize perioperative damage to the paravertebral stabilizing musculotendinous system. The aim of this study was to assess long-term clinical and radiological effects of MIDLF. This prospective cohort study evaluated patients who underwent MIDLF for degenerative spinal instability. Clinical and radiological examinations were performed before and after surgery. Perioperative and postoperative complications were recorded. Follow-up was 2 years. P ≤ 0.05 was considered statistically significant. The study included 64 patients (mean age 58.9± 10.7 years; 41 women [64.1%]). The most frequent indication for MIDLF was degenerative spondylolisthesis grade I (28 cases [43.8%]); the prevalent spinal segment to be fused was L4-L5 (35 cases [54.7%]). Mean duration of surgery was 148.2 ± 28.9 minutes. Relief of low back pain and leg pain was significant and stable in the postoperative period as assessed by visual analog scale (P < 0.001). Of patients, 86.9% reported fair, good, or excellent outcomes in terms of pain relief based on MacNab score 2 years after surgery. Patients' level of function in activities of daily living improved significantly based on Oswestry Disability Index score: from 66.8 ± 9.8 before surgery to 33.9 ± 16.5 2 years after surgery (P < 0.001). X-rays and computed tomography at 12 months showed interbody fusion in 46 cases (73.4%), inconclusive results in 13 cases (20.3%), and no fusion in 4 cases (6.3%). No damage to neural or vascular structures and no failure of hardware or screw loosening were recorded. MIDLF is a safe, efficient method for surgical treatment of lumbar spine instability. Its limited invasiveness contributes to better preservation of paravertebral muscles and enhanced postoperative spinal stability.

Two-Year Outcomes of Midline lumbar Fusion Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion in the Treatment of L4-L5 Degenerative Disease

ObjectiveWe aimed to compare the clinical and radiological outcomes of midline lumbar fusion (MIDLF) versus minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) in patients with degenerative spondylolisthesis and/or stenosis in L4-L5 two years after surgery. MethodsConsecutively treated patients with lumbar pathology who underwent MIDLF (n = 16) and a historical control group who underwent MI-TLIF (n = 34) were included. Clinical symptoms were evaluated using Oswestry Disability Index (ODI), the 36-Item Short-Form Health Survey, and visual analog scale (VAS) scores before surgery and 3, 6, 12, and 24 months after surgery. ResultsThe mean operative time and hematocrit (HCT, Day 1) were significantly shorter and lower in MIDLF cases (174 min vs. 229 min, P < 0.001; 0.34 vs. 0.36, P = 0.037). The MI-TLIF group showed better improvement than the MIDLF group in ODI and VAS back and leg pain at 3 months postoperatively. VAS leg pain was higher in MIDLF than in MI-TLIF cases at 6 months. At 24 months follow-up, VAS back pain was higher in MI-TLIF than in MIDLF cases (P = 0.018). ConclusionMIDLF is comparable to MI-TLIF at L4-5 in clinical outcomes and fusion rates, and the results verified the meaningful advantage of using MIDLF for the elderly with osteoporosis.

Evolution of Minimally Invasive Lumbar Spine Surgery

Spine surgery has evolved over centuries from first being practiced with Hippocratic boards and ladders to now being able to treat spinal pathologies with minimal tissue invasion. With the advent of new imaging and surgical technologies, spine surgeries can now be performed minimally invasively with smaller incisions, less blood loss, quicker return to daily activities, and increased visualization. Modern minimally invasive procedures include percutaneous pedicle screw fixation techniques and minimally invasive lateral approach for lumbar interbody fusion (i.e., minimally invasive transforaminal lumbar interbody fusion, extreme lateral interbody fusion, oblique lateral interbody fusion) and midline lumbar fusion with cortical bone trajectory screws. Just as evolutions in surgical techniques have helped revolutionize the field of spine surgery, imaging technologies have also contributed significantly. The advent of computer image guidance has allowed spine surgeons to advance their ability to refine surgical techniques, increase the accuracy of spinal hardware placement, and reduce radiation exposure to the operating room staff. As the field of spine surgery looks to the future, many novel technologies are on the horizon, including robotic spine surgery, artificial intelligence, and machine learning to help improve preoperative planning, improve surgical execution, and optimize patient selection to ensure improved postoperative outcomes and patient satisfaction. As more spine surgeons begin incorporating these novel minimally invasive techniques into practice, the field of minimally invasive spine surgery will continue to innovate and evolve over the coming years.

Accuracy of cortical bone trajectory screw placement in midline lumbar fusion (MIDLF) with intraoperative cone beam navigation.

Cortical bone trajectory (CBT) screws have been recently described as a method of lumbosacral fixation. These screws are typically inserted under fluoroscopic guidance with a medial-to-lateral trajectory in the axial plane and a caudal-to-cephalad trajectory in the sagittal plane. In an effort to reduce surgeon radiation exposure and improve accuracy, CBT screws may be inserted under navigation with intraoperative cone beam computed tomography (CT). However, the accuracy of CBT screw placement under intraoperative navigation has yet to be assessed in the literature. The purpose of the study was to evaluate the accuracy of CBT screw placement using intraoperative cone beam CT navigation. One hundred and thirty-four consecutive patients who underwent CBT fixation with 618 screws under intraoperative navigation were analyzed from May 2016 through May 2018. Screws were placed by one of three senior spine surgeons using the Medtronic O-Arm Stealth Navigation. Screw position and accuracy were assessed on intraoperative and postoperative CT scans using 2D and 3D reconstructions with VitreaCore software. The majority of surgeries were primary cases (73.1%). The mean age at the time of surgery was 61.5±10.0 years and the majority of patients were female (61.2%). Most patients underwent surgery for a diagnosis of degenerative spondylolisthesis (47.8%) followed by mechanical collapse with foraminal stenosis (22.4%). Ten violations of the vertebral cortex were noted with an average breach distance of 1.0±0.7 mm. Three breaches were lateral (0.5%) and seven were medial (1.1%). The overall navigated screw accuracy rate was 98.3%. The accuracy to within 1 mm of error was 99.2%. There were no intra-operative neurologic, vascular, or visceral complications related to the placement of the CBT screws. CBT screw fixation under an intraoperative cone beam CT navigated insertion technique is safe and reliable. Despite five breaches greater than 1mm, there were no complications related to the placement of the CBT screws in this series.

Comparison of Cortical Bone Trajectory Screw Placement Using the Midline Lumbar Fusion Technique to Traditional Pedicle Screws: A Case-Control Study.

Cortical bone trajectory (CBT) screws are an alternative to traditional pedicle screws (PS) for lumbar fixation. The proposed benefits of CBT screws include decreased approach-related morbidity and greater cortical bone contact to prevent screw pullout. Relatively little data is published on this technique. Here, we compare the midline lumbar fusion (MIDLF) approach for CBT screw placement to transforaminal lumbar interbody fusion (TLIF) for traditional PS placement. A prospectively maintained institutional database was retrospectively reviewed for all patients undergoing lumbar spinal fusion using CBT screws over the past 5 years. Controls were identified from the same database as patients undergoing lumbar spinal fusion with traditional PS placement and matched based on age, sex, and number of levels fused. Exclusion criteria included prior lumbar instrumentation. The electronic health record was retrospectively reviewed for demographic, perioperative, and postoperative data. A total of 23 patients who underwent CBT screw placement and 35 controls who received traditional PS were included in the study. The median follow-up time was 52.5 months. The CBT screw group had significantly less mean estimated blood loss than the PS group (186 mL versus 414 mL respectively; P = .008). Both groups experienced significant improvements in preoperative Oswestry Disability Index (ODI) and visual analog scale (VAS) scores for back and leg pain. However, there was no significant difference between the groups in regard to operative time and amount of improvement in VAS pain score or ODI. The CBT group was associated with a significantly shorter mean length of stay (LOS). There were 2 instances of screw pullout in each group. The MIDLF approach with CBT screw placement is associated with less intraoperative blood loss and shorter LOS than traditional PS placement. There is no difference between the 2 techniques in regard to improvement in pain or disability.

Clinical and Radiological Comparison between Three Different Minimally Invasive Surgical Fusion Techniques for Single-Level Lumbar Isthmic and Degenerative Spondylolisthesis: Minimally Invasive Surgical Posterolateral Fusion versus Minimally Invasive Surgical Transforaminal Lumbar Interbody Fusion versus Midline Lumbar Fusion.

Study DesignRetrospective cohort study.PurposeComparison between three different minimally invasive surgical (MIS) fusion techniques for single-level lumbar spondylolisthesis.Overview of LiteratureThere has been an increase in the development and utilization of MIS techniques for lumbar spine fusion. No study has compared the efficacy of MIS-posterolateral fusion (MIS-PLF), MIS-transforaminal lumbar interbody fusion (MIS-TLIF), and midline lumbar fusion (MIDLF) with modified cortical bone trajectory screws for lumbar spondylolisthesis.MethodsFifty-nine patients with single-level lumbar spondylolisthesis and a minimum follow-up period of 1 year were included in this study. The MIS-PLF, MIS-TLIF, and MIDLF groups included 22, 15, and 22 patients, respectively. The average age of the groups was 70.6, 49.3, and 62.7 years, respectively. The evaluation parameters were operation time, intraoperative bleeding, serum C-reactive protein (CRP) value, creatine kinase (CK) value, and overall functional outcome as per the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) score. The changes in the lumbar lordosis angle (LLA), segmental disc angle (SDA), and disc height were measured. Fusion rate, screw loosening, and loss of correction were also assessed.ResultsMIDLF showed a significantly shorter operation time (111 min), less bleeding amount (112.5 mL), and lower values of CRP and CK than the other two techniques. There was no significant difference in the JOABPEQ scores of the three groups. MIDLF resulted in a greater increase in the LLA and SDA postoperatively. MIDLF and MIS-TLIF resulted in a significant increase in the middle disc height compared with MIS-PLF. MIDLF showed a lower loss of correction after 6 months postoperatively (2.6%) than MIS-PLF (5.2%) and MIS-TLIF (4.2%). The fusion rate was 100% in the MIDLF and MIS-TLIF groups and 90% in the MIS-PLF group. Screw loosening occurred in 10% of the MIS-PLF cases, 7.14% of the MIS-TLIF cases, and 4.76% of the MIDLF cases.ConclusionsMIDLF was the least invasive, and there was no significant difference between the three groups in terms of fusion, screw loosening, and clinical outcomes.

WITHDRAWN: Midline Lumbar Fusion Using Cortical Bone Trajectory Screws for Elderly Patients

Summary Background Midline lumbar fusion (MIDLF) using cortical bone trajectory (CBT) is an alternative method of lumbar spinal fusion. It is useful for reduction not only for approach-related morbidity but also for osteoporosis. This study aimed to present our experience with MIDLF, and focused on survey of postoperative wound pain intensity and outcome assessment. Methods We retrospectively collected patients who met criteria of elderly (age more than 65 years old), spondylolisthesis, disc herniation, or spinal stenosis, and those who received MIDLF operation. By reviewing medical records, we analysed pain scores, complication rates, and screws loosening. Results Between January 2016 and June 2017, 23 patients were enrolled. One patient had screw malposition who needed reoperation. The rest patients showed significant improvement of the leading symptom. The visual analogue scale (VAS) scores for wound pain on the first postoperative day, second postoperative day, and before discharge were 3.4, 2.3, and 1.4, respectively. Early ambulation was achieved owing to the mild postoperative pain. The mean VAS scores for lower back and leg pain improvement were 4.7 and 4.5 respectively in the 3-month follow-up. At the most recent follow-up, all the patients reported maintenance of the satisfactory result. No screw-loosening or other complications were noted. Conclusions In our experience, MIDLF using CBT route seemed to reduce post-op wound pain significantly, so that elderly patients could ambulate earlier. It also had less screws loosening, especially for elderly or osteoporotic patients.

Midline Lumbar Fusion for Patients with Adjacent Segmental Disease after Posterior Lumbar Interbody Fusion: A Comparative Study between Midline Lumbar Fusion and Posterior Lumbar Interbody Fusion

Midline Lumbar Fusion for Patients with Adjacent Segmental Disease after Posterior Lumbar Interbody Fusion: A Comparative Study between Midline Lumbar Fusion and Posterior Lumbar Interbody Fusion

Application of cortical bone trajectory screw in the revision of lumbar disease

Objective To evaluate and discuss the clinical outcomes and advantages of midline lumbar fusion (MIDLF) with cortical bone trajectory (CBT) screw in the reoperation of lumbar disease. Methods From June 2014 to August 2015, a total of 12 patients, 5 male and 7 female with an average age of 68.5±5.6 years old (ranged from 56-76 years). The indications of reoperation including: 5 cases of adjacent segment disease, 2 cases of discogenic back pain after lumbar dynamic stabilization, 5 cases of recurrent disc herniation. The interval time from primary surgery to second surgery was 3-9.5 years (average 6.0±2.0 years). Disease level: L2/3 1 case, L3/4 2 cases, L4/5 7 cases, L5/S1 2 cases. All cases were got the X-ray, CT scan and MRI examination before surgery. The operative duration, blood loss, complications were all evaluated. Back and leg pain were recorded by visual analogue scale (VAS) scores. Functional recovery was evaluated by Oswestry disability index (ODI). Results Operative time was 110-210 min, and mean duration was (158.3±36.4) min. Blood loss was 150-310 ml, and mean loss was (231.7±51.0) ml. There was 1 case of cerebrospinal fluid leakage which treated with pillow supine for 1 week after surgery, and strengthened the prevention of antibiotics, incision healing, with no headache and other low intracranial pressure of dizziness, the remaining patients had no intraoperative and postoperative complications. The time of follow-up was 12-25 months, with an average of (17.9±4.6) months. The back pain of VAS score of preoperative was 3.9±1.4, and the last follow-up was 1.9±0.5, the difference was statistically significant (t=4.506, P=0.001). The VAS score of preoperative leg pain (4.9±1.4) was significant higher than the last follow-up (1.2±0.6, t=9.134, P=0.000). The preoperative ODI was 32.9±3.4, and last follow-up was 13.3±3.2, and the difference was statistically significant (t=15.002, P=0.000). Conclusion MIDLF was applicable with good clinical outcome and technical advantages in current cases, and it might be a choice of reoperation for lumbar disease. Key words: Spinal fusion; Internal fixators; Reoperation

Midline lumbar fusion with cortical bone trajectory as first line treatment in a selected series of patients with lumbar instability.

The aim of the present study was to proof that for certain complex spinal conditions, midline lumbar fusion (MIDLF) technique is very convenient in terms of length of hospitalization, functional recovery and pain relief and time to back to work. MIDLF indications were set for patients with not more than 3 unstable levels, presence of osteoporosis (alternative to cemented screws), or cardiomyopathy with anticoagulation with or without spinal stenosis, and or discopathy. Surgical difficulties, operative time, hemoglobin loss and postoperative 45 days, 6 months and one-year follow-up data are shown. In one-year period MIDLF was applied for 9 patients. For all cases motor deficits improved, pain decreased from a high VAS Score to VAS 1. No complications were seen so far. In one case small pedicles prevented the use of MIDLF technique. Operative time, acceptable hemoglobin loss, short length of stay and encouraging follow-up result indicate that this technique is a valid option to improve patient's quality of life where osteoporosis makes traditional transpedicular screws less stable or where the surgeon has the need to reduce intraoperative blood loss or has to work in a deep surgical field.

Midline lumbar fusion using cortical bone trajectory screws. Preliminary report.

IntroductionMidline lumbar fusion (MIDLF) using cortical bone trajectory is an alternative method of transpedicular spinal fusion for degenerative disease. The new entry points’ location and screwdriving direction allow the approach-related morbidity to be reduced.AimTo present our preliminary experience with the MIDLF technique on the first 5 patients with lumbar degenerative disease and with follow-up of at least 6 months.Material and methodsRetrospective analysis was performed on the first 5 patients with foraminal (4) or central (1) stenosis operated on between December 2014 and February 2015. Three patients were fused at L4–L5 and two at the L5–S1 level.ResultsNo intra- or post-operative complications occurred with this approach. An improvement regarding the leading symptom in the early postoperative period (sciatica 4/4, claudication 1/1) was achieved in all patients. The mean improvements in the visual analogue scale for low back and leg pain were 2.2 and 4.8 respectively. The mean Oswestry Disability Index scores were 52% (range: 16–82%) before surgery and 33% (range: 12–56%) at 3-month follow-up (mean improvement 19%). At the most recent follow-up, 4 patients reported the maintenance of the satisfactory result. The early standing and follow-up X-rays showed satisfactory screw placement in all patients.ConclusionsIn our initial experience, the MIDLF technique seems to be an encouraging alternative to traditional transpedicular trajectory screws when short level lumbar fusion is needed. Nevertheless, longer observations on larger groups of patients are needed to reliably evaluate the safety of the method and the sustainability of the results.

Clinical outcomes during the learning curve of MIDline Lumbar Fusion (MIDLF®) using the cortical bone trajectory.

The objective of this study is to review the clinical outcomes of a novel minimally invasive surgery (MIS) technique for the treatment of instability of the lumbar spine using the cortical bone trajectory (CBT). We present a prospective review of the clinical outcomes from the first 25 consecutive cases in a single unit during the initial learning phase. The investigation group included the first 25 patients (eight males and 17 females) who underwent MIDLF® since the introduction of this technique in a single unit. All patients were operated on by the same surgeon. Patients' demographics, as well as duration their surgery, intraoperative blood loss, duration of hospitalization, and complications were analyzed. From the patients' satisfaction survey; pre and post-operative analgesics use, visual analogue scale (VAS) score for both back pain and radicular symptoms, as well as the Oswestry disability index (ODI) were measured and analyzed. There was a clear improvement in all measured parameters. The median intraoperative blood loss was 250ml (200-700) with an average operative time of 190 (±46) and 237 (±14) min for one- and two-level fixation respectively and a median hospital stay of 2days (1-12) inclusive of the day of surgery. The mean preoperative ODI was 59% (±18.7) versus 34% (±19.5) post-operatively. In this series, 84% of the patients (n = 21) reported a significant reduction in the use of analgesia, and 44% (n = 11) reported total freedom from intake of painkillers. The median postoperative pain-free walking distance increased from 50 (0-3520) to 1000 (0-8880) yards. Three complications were reported without any significant postoperative morbidity. While in this case series the preoperative ODI and back pain VAS significantly predicted the post-operative variable, the same could not be demonstrated for leg pain, preoperative walking distance, number of pain killers, or the patient body mass index (BMI). Our results indicate that lumbar instrumentation using CBT is safe and effective with comparable results to those published for posterior lumbar interbody fusion (PLIF) even with the learning curve of new procedures. Patients who underwent a MIDLF® needed a shorter operative time, and they were mobilized and discharged quicker, with figures almost similar to those from non-instrumented surgery. While in this case series the preoperative ODI and back pain VAS significantly predicted the post-operative variable, the same could not be demonstrated for leg pain, preoperative walking distance, number of pain killers, or the patient BMI. Larger studies with longer follow-up are needed in order to better understand and assess the possible advantages of this technique.

Novel placement of cortical bone trajectory screws in previously instrumented pedicles for adjacent-segment lumbar disease using CT image-guided navigation

Symptomatic adjacent-segment lumbar disease (ASLD) after lumbar fusion often requires subsequent surgical intervention. The authors report utilizing cortical bone trajectory (CBT) pedicle screw fixation with intraoperative CT (O-arm) image-guided navigation to stabilize spinal levels in patients with symptomatic ASLD. This unique technique results in the placement of 2 screws in the same pedicle (1 traditional pedicle trajectory and 1 CBT) and obviates the need to remove preexisting instrumentation. The records of 5 consecutive patients who underwent lumbar spinal fusion with CBT and posterior interbody grafting for ASLD were retrospectively reviewed. All patients underwent screw trajectory planning with the O-arm in conjunction with the StealthStation navigation system. Basic demographics, operative details, and radiographic and clinical outcomes were obtained. The average patient age was 69.4 years (range 58-82 years). Four of the 5 surgeries were performed with the Minimal Access Spinal Technologies (MAST) Midline Lumbar Fusion (MIDLF) system. The average operative duration was 218 minutes (range 175-315 minutes). In the entire cohort, 5.5-mm cortical screws were placed in previously instrumented pedicles. The average hospital stay was 2.8 days (range 2-3 days) and there were no surgical complications. All patients had more than 6 months of radiographic and clinical follow-up (range 10-15 months). At last follow-up, all patients reported improved symptoms from their preoperative state. Radiographic follow-up showed Lenke fusion grades of A or B. The authors present a novel fusion technique that uses CBT pedicle screw fixation in a previously instrumented pedicle with intraoperative O-arm guided navigation. This method obviates the need for hardware removal. This cohort of patients experienced good clinical results. Computed tomography navigation was critical for accurate CBT screw placement at levels where previous traditional pedicle screws were already placed for symptomatic ASLD.

Midline lumbar fusion with cortical bone trajectory screw.

A novel cortical bone trajectory (CBT) screw technique provides an alternative fixation technique for lumbar spine. Trajectory of CBT screw creates a caudo-cephalad path in sagittal plane and a medio-lateral path in axial plane, and engages cortical bone in the pedicle. The theoretical advantage is that it provides enhanced screw grip and interface strength. Midline lumbar fusion (MIDLF) is composed of posterior mid-line approach, microsurgical laminectomy, and CBT screw fixation. We adopted the MIDLF technique for lumbar spondylolisthesis. Advantages of this technique include that decompression and fusion are available in the same field, and it minimizes approach-related damages. To determine whether MIDLF with CBT screw is as effective as traditional approach and it is minimum invasive technique, we studied the clinical and radiological outcomes of MIDLF. Our results indicate that MIDLF is effective and minimum invasive technique. Evidence of effectiveness of MIDLF is that patients had good recovery score, and that CBT screw technique was safety in clinical and stable in radiological. MIDLF with CBT screw provides the surgeon with additional options for fixation. This technique is most likely to be useful for treating lumbar spondylolisthesis in combination with midline decompression and insertion of an interbody graft, such as the transforaminal lumbar interbody fusion or posterior lumbar interbody fusion techniques.