A retrospective Chinese study on optical-electromagnetic navigation-guided biportal endoscopic unilateral laminotomy for bilateral decompression in lumbar spinal stenosis: improving precision and efficiency.

The application of different surgical navigation technologies has been moderate in gaining widespread acceptance on account of accuracy concerns, the technical complexity of different navigation systems and the cost-effectiveness. Until now, there is no study concentrated on integration of optical and electromagnetic system to solve the above problems. This study aims to develop a novel optical and electromagnetic integrated surgical navigation system and evaluate the accuracy. The components, key techniques, and operating mechanisms of an optical and electromagnetic integrated surgical navigation system were detailed described. A tailored prosthesis module was used to estimate the technical error of the novel navigation system. The application accuracy of optical and electromagnetic navigation function was respectively evaluated in a controlled animal experiment. The technical error of optical electromagnetic integrated navigation system was 0.5±0.1mm in the phantom study. The application accuracy of electromagnetic navigation was 1.82±0.05mm in the in-vivo experiment. The application accuracy of optical navigation has detected no significant difference between experimental group and controlled group. The absolute translation and angular errors of all K-wires in both axial and sagittal planes found no significant difference between two groups. However, axial translational errors were higher than sagittal translation errors within the experimental group or the controlled group. Compared with in-vivo studies, a significantly lower needle-position error was found in the phantom study. The novel optical and electromagnetic integrated surgical navigation system is demonstrated that it not only retains the accuracy and stability compared with the traditional optical navigation system, but also has high precision electromagnetic navigation function. The registration accuracy of navigation can only represent the principle error of engineering, and the overall error of the actual application of navigation system should include the system registration error, human operation error and the error of navigation special tools.

Introduction Prolapsed intervertebral disc and lumbar canal stenosis have been major challenging problem of mankind since ages. Many different methods have been evolved for its diagnosis and management. The purpose of this study is to determine the efficacy and safety of unilateral laminotomy for decompression in case of PIVD and lumbar canal stenosis compared with conventional laminectomy. Materials and Methods A retrospective and prospective study of 40 patients who had undergone surgery for PIVD or lumbar canal stenosis at our institute was performed. They were assigned in the two groups: Group 1 ( n = 20) consisted of patients who underwent laminotomy for decompression, and Group 2 ( n = 20) consisted of patients treated by decompressive laminectomy. Neurological status of the patients was evaluated by physical examination both pre- and postoperatively. Pain, disability, and other criteria were assessed by Greenough scoring system. Plain AP and lateral radiographs and MRI of concerned segment of every patient were obtained. Lumbar flexion-extension films were obtained to assess spinal instability. Minimum follow-up was done at 6 months and results were assessed by using Greenough scoring system and radiographs at final follow-up. Results Excellent clinical outcome was obtained in 80% of patients in Group 1 and in 65% of patients in Group 2. Increase in Greenough score was more in Group 1. Postoperative spinal instability occurred in four patients in Group 2, none in Group 1. Early rehabilitation and early return to work was more possible in Group 1. There was one surgical complication in the each group (dural tear dealt during surgery). Postoperative infection developed in four patients (two in each group) among which one require surgical debridement in Group 2. Neurological impairment occurred in one patient in Group 2. Conclusion Duration of hospital stay is significantly reduced amongst the patients operated by unilateral laminotomy compared with laminectomy, and rehabilitation was also faster by starting earlier sitting and thereby reducing morbidity and burden to hospital. Consequent earlier return to normal routine life can be expected. Although overall outcome of the patients at final follow-up remains mostly unchanged, technique of sparing unilateral paraspinal muscles and thereby sparing supraspinous and interspinous ligaments does help in earlier rehabilitations of the patients, fastens the recovery, and thereby reducing psychiatric problems related to it, saves many man hours of one's life going in wastage and brings in overall feeling of well-being and patient satisfaction. Disclosure of Interest None declared References Young S, Veerapen R, O’Laoire SA. Relief of lumbar canal stenosis using multilevel subarticular fenestrations as an alternative to wide laminectomy: preliminary report. Neurosurgery 1988;23(5):628–633 Spetzger U, Bertalanffy H, Naujokat C, von Keyserlingk DG, Gilsbach JM. Unilateral laminotomy for bilateral decompression of lumbar spinal stenosis. Part I: Anatomical and surgical considerations. Acta Neurochir (Wien) 1997;139(5):392–396 Weiner BK, Walker M, Brower RS, McCulloch JA. Microdecompression for lumbar spinal canal stenosis. Spine 1999;24(21):2268–2272 Cavuşoğlu H, Türkmenoğlu O, Kaya RA, et al. Efficacy of unilateral laminectomy for bilateral decompression in lumbar spinal stenosis. Turk Neurosurg 2007;17(2):100–108 Guiot BH, Khoo LT, Fessler RG. A minimally invasive technique for decompression of the lumbar spine. Spine 2002;27(4):432–438 Kim SW, Ju CI, Kim CG, Lee SM, Shin H. Minimally invasive lumbar spinal decompression: a comparative study between bilateral laminotomy and unilateral laminotomy for bilateral decompression. J Korean Neurosurg Soc 2007;42(3):195-199 Greenough CG, Fraser RD. Assessment of outcome in patients with low-back pain. Spine 1992;17(1):36–41 Greenough CG. Results of treatment of lumbar spine disorders. Effects of assessment techniques and confounding factors. Acta Orthop Scand Suppl 1993;251(Suppl 251):126–129

Radiological Outcomes of Unilateral Laminotomy for Bilateral Decompression in Lumbar Spinal Stenosis With and Without Discectomy

Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression for Lumbar Spinal Stenosis Provides Comparable Clinical Outcomes in Patients with and without Degenerative Spondylolisthesis

Laminectomy and bilateral laminotomy are the standard procedures for decompression of lumbar spinal stenosis (LSS). With the aim of less invasiveness and better preservation of spinal stability, the technique of unilateral laminotomy for bilateral decompression (ULBD) was developed. However, limited follow-up data exist to determine the efficiency and outcome of ULBD. Therefore, the authors present their 10-year experience with ULBD and postoperative long-term results. One hundred thirty-three consecutive patients (73 men and 60 women; mean age, 63 yr) meeting clinical and radiographic criteria for LSS who underwent first-time ULBD between 1994 and 1999 entered the study. The study parameters were set to ensure a follow-up period of at least 4 years. All patients were available for short-term follow-up re-evaluation within 3 months, and 102 (77%) of the 133 patients were available for long-term examination after a mean duration of 5.6 years. The scale of Finneson and Cooper was used for evaluation of the clinical results. One hundred thirty patients (97.7%) improved immediately after surgery. Ninety-four (92.2%) of the 102 patients available for long-term follow-up examination remained improved, and 85.3% had an excellent-to-fair operative result. The incidence of complications was 9.8%. Resurgery for complication was necessary in three patients, for restenosis in seven patients, and for spinal instability in two patients, accounting for a reoperation rate of 11.8%. ULBD allows achievement of good and long-lasting operative results in patients with LSS. Postoperative deterioration, recurrences, and spinal instability are infrequent. For the authors, ULBD is the preferred technique to treat symptomatic LSS.

Hybrid optical and electromagnetic navigation for mandibular angle osteotomy.

Uniportal full-endoscopic unilateral laminotomy for bilateral decompression (UFE-ULBD) has been used to treat lumbar spinal stenosis (LSS) with satisfactory outcomes. However, a limited number of studies have investigated the relationship between decompression range and clinical outcomes. This study aimed to investigate the efficacy of UFE-ULBD for single-segment LSS and to explore the relationship between the decompression range and functional outcomes. Single-segment LSS patients who had undergone UFE-ULBD using an interlaminar approach between November 2021 and February 2023 were retrospectively analyzed. Patient demographics, visual analogue scale (VAS) scores for leg and back pain, Oswestry disability index (ODI) scores, modified MacNab grades, and radiological outcomes, including the decompression ratio of the disc-flava ligament space and osseous lateral recess, the enlargement ratio of superior articular process interval, lamina interval dural sac cross-sectional area (DSCA), were collected. The independent sample t-tests, paired sample t-tests, chi-square tests, Fisher's exact tests, and Pearson's and Spearman's correlation analyses were used. Forty patients (23 males, and 17 females) were retrospectively enrolled in this study. The mean follow-up period was 12 months. At the last follow-up, VAS scores for leg pain and back pain decreased from 6.0 ± 0.8 to 1.0 ± 1.9 (p < 0.001), and from 6.0 ± 0.8 to 1.2 ± 1.8 (p < 0.001) respectively; ODI score decreased from 71.7 ± 6.2 to 24.3 ± 21.3 (p < 0.001). According to the modified MacNab criteria, the results were excellent in 28 (70%), good in 5 (12.5%), fair in 6 (15%), and poor in 1 (2.5%), with an excellent-good rate of 82.5%. The postoperative DSCA enlarged from 57.69 ± 21.86 to 150.75 ± 39.33 mm2 (p < 0.001), with an enlargement ratio of 189.43 ± 107.83%. No difference in clinical or radiological parameters was detected between patients with excellent, good, fair, or poor outcomes based on the modified MacNab criteria. UFE-ULBD can provide satisfactory clinical and radiological outcomes in single-segment LSS patients. With sufficient exposure to the dural sac boundary, the functional outcome was not related to the radiological decompression range in LSS patients who had undergone UFE-ULBD.

Multicenter retrospective cohort study. The aim of this study was to compare reoperation rates at 5-year follow-up of unilateral laminotomy for bilateral decompression (ULBD) versus posterior decompression with instrumented fusion (Fusion) for patients with low-grade degenerative spondylolisthesis (DS) with lumbar spinal stenosis (LSS) in a multicenter database. Controversy exists regarding whether fusion should be used to augment decompression surgery in patients with LSS with DS. For years, the standard has been fusion with standard laminectomy to prevent postoperative instability. However, this strategy is not supported by Level 1 evidence. Instability and reoperations may be reduced or prevented using less invasive decompression techniques. We identified 164 patients with DS and LSS who underwent ULBD between January 2007 and December 2011 in a multicenter database. These patients were propensity score-matched on age, sex, race, and smoking status with patients who underwent Fusion (n = 437). Each patient required a minimum of 5-year follow-up. The primary outcome was 5-year reoperation. Secondary outcome measures included postoperative complication rates, blood loss during surgery, and length of stay. Logistic regression models were used to estimate the odds ratio of the 5-year reoperation rate between the two surgical groups. The reoperation rate at 5-year follow-up was 10.4% in the ULBD group and 17.2% in the Fusion group. ULBD reoperations were more frequent at the index surgical level; Fusion reoperations were more common at an adjacent level. The two types of operations had similar postoperative complication rates, and both groups tended to have fusion reoperations. For patients with stable DS and LSS, ULBD is a viable, durable option compared to fusion with decreased blood loss and length stay, as well as a lower reoperation rate at 5-year follow-up. Further prospective studies are required to determine the optimal clinical scenario for ULBD in the setting of DS. 3.

BackgroundUnilateral laminotomy for bilateral decompression (ULBD) is a MIS surgical technique that offers safe and effective decompression of lumbar spinal stenosis (LSS) with a long-term resolution of symptoms. Advantages over conventional open laminectomy include reduced expected blood loss, muscle damage, mechanical instability, and less postoperative pain. The slalom technique combined with navigation is used in multi-segmental LSS to improve the workflow and effectiveness of the procedure.MethodsWe outline ten technical steps to achieve a slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation. In a retrospective case series, we included patients with multi-segmental LSS operated in our institution using the sULBD between 2020 and 2022. The primary outcome was a reduction in pain measured by Visual Analogue Scale (VAS) for back pain and leg pain and Oswestry Disability Index (ODI).ResultsIn our case series (N = 7), all patients reported resolution of initial symptoms on an average follow-up of 20.71 ± 9 months. The average operative time and length of hospital stay were 196.14 min and 1.67 days, respectively. On average, VAS (back pain) was 4.71 pre-operatively and 1.50 on long-term follow-up of an average of 19.05 months. VAS (leg pain) decreased from 4.33 to 1.21. ODI was reported as 33% pre-operatively and 12% on long-term follow-up.ConclusionThe sULBD with navigation is a safe and effective MIS surgical procedure and achieves the resolution of symptoms in patients presenting with multi-segmental LSS. Herein, we demonstrate the ten key steps required to perform the sULBD technique. Compared to the standard sULBD technique, the incorporation of navigation provides anatomic localization without exposure to radiation to staff for a higher safety profile along with a fast and efficient workflow.

OBJECTIVEThe management of lumbar spinal stenosis (LSS) with concurrent scoliosis and/or spondylolisthesis remains controversial. Full-endoscopic unilateral laminotomy for bilateral decompression (ULBD) facilitates neural decompression while preserving stabilizing osseoligamentous structures and may be uniquely suited for the treatment of LSS with concurrent mild to moderate degenerative deformity. The safety and efficacy of full-endoscopic versus minimally invasive surgery (MIS) ULBD in this patient population is studied here for the first time.METHODSA retrospective analysis of prospectively collected data was conducted on 45 consecutive LSS patients with concurrent scoliosis (≥ 10° coronal Cobb angle) and/or spondylolisthesis (≥ 3 mm). Patient demographics, operative details, complications, and imaging characteristics were reviewed. Outcomes were quantified using back and leg visual analog scale (VAS) scores and the Oswestry Disability Index (ODI) at 2 weeks, 3 months, and 1 year.RESULTSA total of 26 patients underwent full-endoscopic and 19 underwent MIS-ULBD with an average follow-up period of 12 months. The endoscopic cohort experienced a significantly shorter hospital length of stay (p = 0.014) and fewer adverse events (p = 0.010). Both cohorts experienced significant improvements in VAS and ODI scores at all time points (p < 0.001), but the endoscopic cohort demonstrated significantly better early ODI scores (p = 0.024).CONCLUSIONSEndoscopic and MIS-ULBD result in similar functional outcomes for LSS with mild to moderate deformity, while the endoscopic approach demonstrates a favorable rate of complications. Further studies are required to better delineate the characteristics of spinal deformities amenable to this approach and the durability of functional results.

PurposeThe purpose of this study is to compare and analyze the precision of optical and electromagnetic navigation systems in total knee arthroplasty (TKA).Materials and MethodsWe retrospectively reviewed 60 patients who underwent TKA using an optical navigation system and 60 patients who underwent TKA using an electromagnetic navigation system from June 2010 to March 2012. The mechanical axis that was measured on preoperative radiographs and by the intraoperative navigation systems were compared between the groups. The postoperative positions of the femoral and tibial components in the sagittal and coronal plane were assessed.ResultsThe difference of the mechanical axis measured on the preoperative radiograph and by the intraoperative navigation systems was 0.6 degrees more varus in the electromagnetic navigation system group than in the optical navigation system group, but showed no statistically significant difference between the two groups (p>0.05). The positions of the femoral and tibial components in the sagittal and coronal planes on the postoperative radiographs also showed no statistically significant difference between the two groups (p>0.05).ConclusionsIn TKA, both optical and electromagnetic navigation systems showed high accuracy and reproducibility, and the measurements from the postoperative radiographs showed no significant difference between the two groups.

BACKGROUND We aimed to compare the effectiveness of microscopic unilateral laminotomy for bilateral decompression (ULBD) and microscopic bilateral laminotomy for bilateral decompression (BLBD) in the early postoperative period among patients with single-level lumbar spinal stenosis (LSS). MATERIAL AND METHODS A retrospective cohort study was conducted on patients with LSS who underwent ULBD or BLBD between January 2020 and December 2023, including 94 patients who underwent ULBD and 58 who underwent BLBD. Patient demographics, comorbidities, smoking status, and data related to LSS were reviewed. Preoperative and postoperative assessments on day 10 included back pain visual analog scale (VAS), walking distance, and Odom criteria. Disability was evaluated using the self-assessment Oswestry Disability Index (ODI) preoperatively and on day 30. Additionally, wound infection, postoperative modified MacNab criteria, and pain (back, leg, and hip) were recorded. RESULTS Age and sex were similar in the 2 groups. Both surgeries significantly reduced low back pain, increased walking distance, and improved Odom category on day 10, compared with baseline (P<0.001 for all). A significant decrease in 30-day ODI, compared with baseline, was observed in both groups (P<0.001 for both). The ULBD group had a significantly higher percentage of patients with wound infection (P=0.014); however, the ODI score among ULBD recipients was significantly lower (better) on day 30 (P=0.047). CONCLUSIONS ULBD may represent a less invasive, more effective, and safer surgical alternative than BLBD and classical laminectomy in patients with single-level LSS, but precautions are essential concerning wound infection.

Full-endoscopic spine surgery for degenerative lumbar diseases is growing in popularity and has shown favourable outcomes. Lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) has been used to treat lumbar spinal stenosis (LSS). However, studies comparing LE-ULBD to microscopic ULBD are lacking. This study compared the clinical efficacy and radiological outcomes between the LE-ULBD and microscopic ULBD. The study retrospectively enrolled patients undergoing either LE-ULBD or microscopic ULBD for spinal stenosis at the L4-L5 level. The demographic data, operative details, radiological images, clinical outcomes, and complications of patients from the two groups were compared through matched-pairs analysis. The minimum follow-up duration was 24months. There were 93 patients undergoing either LE-ULBD (n = 42) or microscopic ULBD (n = 51). The patient demographics were similar between the two groups. The LE-ULBD group had significantly less estimated blood loss, less analgesic use, and shorter hospitalization duration (P < .05). The endoscopic group had a significantly lower visual analog scale for back pain at all follow-up intervals compared with the microscopic group (P < .05). There were no significant differences in leg pain or Oswestry Disability Index. The cross-section area of the spinal canal was significantly wider after microscopic ULBD. There were no significant differences in post-operative degenerative changes in disc height, translational motion, or facet preservation rate. LE-ULBD is comparable in clinical and radiological outcomes with enhanced recovery for single-level LSS. The endoscopic approach might further minimize tissue injury and enhance post-operative recovery.

Lumbar spinal stenosis (LSS) involves the narrowing of the spinal canal due to degenerative changes in the vertebral joints, intervertebral discs, and ligaments. LSS encompasses central canal stenosis (CCS), lateral recess stenosis (LRS), and intervertebral foramen stenosis (IFS). The utilization of lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) has gained popularity in the treatment of CCS and LRS. This popularity is attributed to the rapid development of endoscopic instruments and the progress of endoscopic philosophy. In this technical report, a detailed introduction to the steps and key points of LE-ULBD is provided. Simultaneously, a retrospective review of 132 consecutive patients who underwent LE-ULBD for central canal and/or lateral recess stenosis was conducted. The outcomes after more than two years of follow-up were assessed using the visual analogue score (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) scores, and the modified MacNab criteria to evaluate surgical efficacy. All 132 patients underwent LE-ULBD successfully. Among them, 119 patients were rated as "excellent," while 13 patients were rated as "good" based on the modified MacNab criteria during the last follow-up. Incidental dural tears occurred in four cases, but there were no post-operative epidural hematomas or infections. The experience demonstrates that LE-ULBD is a less invasive, effective, and safe approach. It can be considered as an alternative option for treating patients with lumbar central canal stenosis and/or lateral recess stenosis.

Purpose To evaluate the clinical value of CT-guided radiofrequency ablation (RFA) in the diagnosis and treatment of pulmonary metastases under optical and electromagnetic navigation. Methods Data on CT-guided radiofrequency ablation treatment of 93 metastatic lung lesions in 70 patients were retrospectively analyzed. There were 46 males and 24 females with a median age of 60.0 years (16–85 years). All lesions were ≤3cm in diameter. 57 patients were treated with 17 G radiofrequency ablation needle puncture directly ablated the lesion without biopsy, and 13 patients were treated with 16 G coaxial needle biopsy followed by radiofrequency ablation. There were 25 cases in the optical navigation group, 25 in the electromagnetic navigation group, and 20 in the non-navigation group. The navigation group was performed by primary interventionalists with less than 5 years of experience, and the non-navigation group was performed by interventionalists with more than 5 years of experience. Result All operations were successfully performed. There was no statistically significant difference in the overall distribution of follow-up results among the optical, electromagnetic, and no navigation groups. Complete ablation was achieved in 84 lesions (90.3%). 7 lesions showed incomplete ablation and were completely inactivated after repeat ablation. 2 lesions progressed locally, and one of them still had an increasing trend after repeat ablation. No serious complications occurred after the operation. Conclusions Treatment with optical and electromagnetic navigation systems by less experienced operators has similar outcomes to traditional treatments without navigational systems performed by more experienced operators.