1.Biportal endoscopic lumbar interbody fusion using a large polyetheretherketone cage: preliminary results
Sang-Min PARK ; Hyun-Jin PARK ; Ki-Han YOU ; Ho-Joong KIM ; Jin S. YEOM
Asian Spine Journal 2025;19(2):252-258
Methods:
Twelve consecutive patients underwent single-level BELIF for lumbar degenerative disease. The technique involves two small portals, one each for endoscopy and instruments. A large PEEK cage was inserted through a posterolateral approach. Clinical outcomes, including a Visual Analog Scale for back and leg pain, the Oswestry Disability Index, and the European Quality of Life-5 Dimensions, were assessed preoperatively and at 3, 6, and 12 months postoperatively. Fusion status was evaluated using computed tomography (CT) at 12 months.
Results:
The mean patient age was 69.1±7.2 years, with operations predominantly at the L4–5 level (83%). The mean operation time was 149.7±37.4 minutes, and the average surgical drainage was 201.4±59.7 mL. All clinical outcome measures showed significant improvement at 12 months (p<0.05). Fusion was achieved in 83.3% of patients. Cage subsidence (>1 mm) occurred in one patient (8.3%). Complications included one case each of incidental durotomy, wrong-site surgery, and wound dehiscence and three cases of asymptomatic hematoma.
Conclusions
BELIF using a large PEEK cage demonstrated promising clinical outcomes and fusion rates. The technique offers enhanced visualization and enables direct neural decompression while minimizing tissue trauma. The use of a large PEEK cage may contribute to improved stability and reduced subsidence risk.
2.Biportal endoscopic lumbar interbody fusion using a large polyetheretherketone cage: preliminary results
Sang-Min PARK ; Hyun-Jin PARK ; Ki-Han YOU ; Ho-Joong KIM ; Jin S. YEOM
Asian Spine Journal 2025;19(2):252-258
Methods:
Twelve consecutive patients underwent single-level BELIF for lumbar degenerative disease. The technique involves two small portals, one each for endoscopy and instruments. A large PEEK cage was inserted through a posterolateral approach. Clinical outcomes, including a Visual Analog Scale for back and leg pain, the Oswestry Disability Index, and the European Quality of Life-5 Dimensions, were assessed preoperatively and at 3, 6, and 12 months postoperatively. Fusion status was evaluated using computed tomography (CT) at 12 months.
Results:
The mean patient age was 69.1±7.2 years, with operations predominantly at the L4–5 level (83%). The mean operation time was 149.7±37.4 minutes, and the average surgical drainage was 201.4±59.7 mL. All clinical outcome measures showed significant improvement at 12 months (p<0.05). Fusion was achieved in 83.3% of patients. Cage subsidence (>1 mm) occurred in one patient (8.3%). Complications included one case each of incidental durotomy, wrong-site surgery, and wound dehiscence and three cases of asymptomatic hematoma.
Conclusions
BELIF using a large PEEK cage demonstrated promising clinical outcomes and fusion rates. The technique offers enhanced visualization and enables direct neural decompression while minimizing tissue trauma. The use of a large PEEK cage may contribute to improved stability and reduced subsidence risk.
3.Biportal endoscopic lumbar interbody fusion using a large polyetheretherketone cage: preliminary results
Sang-Min PARK ; Hyun-Jin PARK ; Ki-Han YOU ; Ho-Joong KIM ; Jin S. YEOM
Asian Spine Journal 2025;19(2):252-258
Methods:
Twelve consecutive patients underwent single-level BELIF for lumbar degenerative disease. The technique involves two small portals, one each for endoscopy and instruments. A large PEEK cage was inserted through a posterolateral approach. Clinical outcomes, including a Visual Analog Scale for back and leg pain, the Oswestry Disability Index, and the European Quality of Life-5 Dimensions, were assessed preoperatively and at 3, 6, and 12 months postoperatively. Fusion status was evaluated using computed tomography (CT) at 12 months.
Results:
The mean patient age was 69.1±7.2 years, with operations predominantly at the L4–5 level (83%). The mean operation time was 149.7±37.4 minutes, and the average surgical drainage was 201.4±59.7 mL. All clinical outcome measures showed significant improvement at 12 months (p<0.05). Fusion was achieved in 83.3% of patients. Cage subsidence (>1 mm) occurred in one patient (8.3%). Complications included one case each of incidental durotomy, wrong-site surgery, and wound dehiscence and three cases of asymptomatic hematoma.
Conclusions
BELIF using a large PEEK cage demonstrated promising clinical outcomes and fusion rates. The technique offers enhanced visualization and enables direct neural decompression while minimizing tissue trauma. The use of a large PEEK cage may contribute to improved stability and reduced subsidence risk.
4.Is minimally invasive surgery a game changer in spinal surgery?
Sang-Min PARK ; Ho-Joong KIM ; Jin S. YEOM
Asian Spine Journal 2024;18(5):743-752
Minimally invasive spine surgery (MISS) has revolutionized the treatment of spinal disorders over the past few decades. This review provides an in-depth analysis of MISS techniques, technologies, outcomes, and future directions. The evolution of MISS techniques–including tubular retractor systems, percutaneous pedicle screw fixation, minimally invasive transforaminal lumbar interbody fusion, lateral lumbar interbody fusion, and endoscopic spine surgery–has expanded the scope of treatable spinal pathologies while minimizing tissue trauma. Technological advancements such as intraoperative navigation, robotics, and augmented reality applications have enhanced precision and capabilities. Clinical evidence supports the efficacy and safety of MISS techniques for various spinal pathologies, demonstrating comparable or superior outcomes to traditional open approaches with reduced tissue trauma, blood loss, and hospital stays. Cost-effectiveness analyses also favor MISS over open techniques. Future directions in MISS include expanding indications, integrating artificial intelligence and machine learning, advancing tissue engineering and biologics, and refining robotic and augmented reality applications. As MISS continues to evolve, it is poised to play an increasingly important role in the treatment of spinal disorders, offering improved patient outcomes with reduced morbidity. However, ongoing rigorous evaluation of new techniques and technologies is crucial to balance potential benefits with associated risks and costs.
5.A Novel Trajectory of C7 Laminar Screws Determined Using Three-Dimensional Computed Tomography and Surgical Simulation Software: Comparison with a Pre-existing Trajectory
Chee Kean LEE ; Quan You LI ; Jiwon PARK ; Sang-Min PARK ; Ho-Joong KIM ; Bong-Soon CHANG ; Byungjun WOO ; Jin S. YEOM
Asian Spine Journal 2023;17(4):639-646
Methods:
Computed tomographic scans of a total of 50 male and 50 female patients were utilized. The placement of C7 laminar screws was activated employing the new and old trajectories. The success rate, the causes of failure, and the maximum allowable length of each trajectory were compared.
Results:
Employing the new trajectory, the success rates of the unilaminar and bilaminar screws were 93% and 83%, respectively, which were significantly better than the old trajectory (80%, p<0.0001 and 70%, p=0.0003). The most prevalent cause of failure was laminar cortical breach followed by facet joint violation. The new trajectory also offered significantly longer maximum allowable screw length in unilaminar (32.5±4.3 mm vs. 26.5±2.6 mm, p<0.001), bilaminar cephalic (29.5±3.8 mm vs. 25.9±2.6 mm, p<0.0001) and bilaminar caudal (33.1±2.6 mm vs. 25.8±3.1 mm, p<0.001) screws than the old trajectory. With the new and old trajectories, 70% vs. 6% of unilaminar, 60% vs. 2% of bilaminar caudal, and 32% vs. 4% of bilaminar cephalic screws could be protracted perfectly into the corresponding lateral mass without any laminar cortical or facet joint violation (p<0.0001).
Conclusions
The novel trajectory possesses a substantially higher success rate, longer maximum allowable screw length, and higher chance to be extended into the lateral mass (a condition known as a lamino-lateral mass screw) than the old trajectory.
6.The Feasibility of Multiple Fixation Points in C2
Quyen Nguyen NGOC ; K. Daniel RIEW ; So Min LEE ; Sang-Min PARK ; Ho-Joong KIM ; Bong-Soon CHANG ; Sang-Hun LEE ; Jae Chul LEE ; Jin S. YEOM
Asian Spine Journal 2023;17(5):888-893
Methods:
We used 1.0-mm interval computed tomographic scan images of 100 patients (50 men and 50 women) and screw trajectory simulation software. The diameter of all screws was set at 3.5 mm, considering its common usage in real surgery. The anatomical feasibility of placing both pedicle and laminar screws on the same side was evaluated. For all feasible sides, the three-dimensional distance between the screw entry points was measured.
Results:
In 85% of cases, both pedicle and laminar screws could be placed on both sides, allowing for the insertion of 4 screws. In 11% of cases, 2 screws could be placed on one side, while only 1 screw was feasible on the other side, resulting in the placement of 3 screws. In all 181 sides where both types of screws could be inserted, the distance between their entry points exceeded 16.1 mm, which was sufficient to prevent the collision between the screw heads.
Conclusions
C2 vertebra can accommodate three (11%) or four (85%) screws in 96% of cases.
7.The Impact of Persistent Low Weight Status on the Occurrence of Vertebral Fractures: A Nationwide PopulationBased Cohort Study
Sang-Min PARK ; Jiwon PARK ; Sangsoo HAN ; Hae-Dong JANG ; Jae-Young HONG ; Kyungdo HAN ; Ho-Joong KIM ; Jin S. YEOM
Journal of Korean Medical Science 2023;38(7):e48-
Background:
Although, being underweight is commonly associated with osteoporosis and sarcopenia, its association with vertebral fractures (VFs), is less well researched. We investigated the influence of cumulative, chronic periods of low weight and changes in body weight on VF development.
Methods:
We used a nationwide, population-based database with data on people (> 40 years) who attended three health screenings between January 1, 2007, and December 31, 2009 to assess the incidence of new VFs. Cox proportional hazard analyses were used to establish the hazard ratios (HRs) for new VFs based on the degree of body mass index (BMI), the cumulative numbers of underweight participants, and temporal change in weight.
Results:
Of the 561,779 individuals in this analysis, 5,354 (1.0%) people were diagnosed three times, 3,672 (0.7%) were diagnosed twice, and 6,929 (1.2%) were diagnosed once. The fully adjusted HR for VFs in underweight individuals was 1.213. Underweight individuals diagnosed only once, twice, or three times had an adjusted HR of 0.904, 1.443, and 1.256, respectively. Although the adjusted HR was higher in adults who were consistently underweight, there was no difference in those who experienced a temporal change in body weight. BMI, age, sex, and household income were significantly associated with VF incidence.
Conclusion
Low weight is a risk factor for VFs in the general population. Given the significant correlation between cumulative periods of low weight and the risk of VFs, it is necessary to treat underweight patients before a VF to prevent its development and other osteoporotic fractures.
8.Evaluation of the efficacy and safety of epidural steroid injection using a nonparticulate steroid, dexamethasone or betamethasone:a double-blind, randomized, crossover, clinical trial
Guen Young LEE ; Joon Woo LEE ; Eugene LEE ; Jin S. YEOM ; Ki-Jeong KIM ; Hyung-Ik SHIN ; Heung Sik KANG
The Korean Journal of Pain 2022;35(3):336-344
Background:
The U.S. Food and Drug Administration has prohibited epidural steroid injection (ESI) with particulate steroids. Thus, this study aimed to compare the efficacy and safety of ESI with two nonparticulate steroids, dexamethasone and betamethasone.
Methods:
The eligible patients (n = 600) who received ESI (0 week) with dexamethasone (ESI-dexa) or betamethasone (ESI-beta) had follow-up visits at 2, 4, and 8 weeks with a phone interview at 12 weeks. The primary endpoint was the proportion of effective responders without pain or who were much improved at 2 weeks. The secondary endpoints were the proportion of crossover injections at 2 weeks; changes in the visual analog scale (VAS) and disability index scores at 2, 4, and 8 weeks; the number of additional ESIs in 12 weeks; the number of participants having spinal surgery, as well as the incidence of adverse events over the 12 weeks.
Results:
The proportion of effective responders at 2 weeks was not different between ESI-beta (72/216, 33.3%) and ESI-dexa (63/200, 31.5%; P = 0.670). Adverse events were more common with ESI-dexa (40/200, 20.0%) than with ESI-beta (24/216, 11.1%; P = 0.012). VAS scores decreased more with ESI-beta than with ESI-dexa at 2 weeks (difference, 0.35; P = 0.023) and 4 weeks (difference, 0.42; P = 0.011). The disability score improved significantly more with ESI-beta compared with ESI-dexa at 2 weeks (difference, 3.37; P = 0.009), 4 weeks (difference, 4.01; P = 0.002), and 8 weeks (difference, 3.54; P = 0.007).
Conclusions
Betamethasone would be more appropriate for ESI.
9.Recent Updates on Minimally Invasive Spine Surgery: Techniques, Technologies, and Indications
Jun-Young CHOI ; Sang-Min PARK ; Ho-Joong KIM ; Jin S. YEOM
Asian Spine Journal 2022;16(6):1013-1021
A number of minimally invasive spine surgeries (MISSs) have been developed to address the drawbacks of open spine surgery. Their advantages include small skin incisions, reduction in tissue damage, quick recovery, and short hospital stay. However, the clinical outcomes are comparable to open surgery. There was a cap on the number of indications that could be set for all spinal illnesses. The indications for MISSs have been expanding owing to mechanical and technological advances in medical equipment. Thus, this review presents the various MISSs developed to date, surgical indications, surgical techniques, and their advantages and disadvantages.
10.Volumetric Assessment of Fusion Mass and Its Clinical Correlations in Posterior Lumbar Interbody Fusion Depending on the Type of Bone Graft
Jae Won LEE ; Quan You LI ; Kyoung-Tak KANG ; Bong-Soon CHANG ; Choon-Ki LEE ; Jin S. YEOM ; Ho-Joong KIM
Journal of Korean Society of Spine Surgery 2020;27(2):39-47
Objectives:
This study was conducted to analyze associations between the volume of the fusion mass and clinical outcomes 1 year after posterior lumbar interbody fusion (PLIF).Summary of Literature Review: No study has investigated associations between the size of the fusion mass and clinical outcomes after PLIF.
Materials and Methods:
The volume of the fusion mass and its clinical correlations after PLIF were analyzed in all patients and in subgroups. When a sufficient amount of local bone was available for grafting, only local bone without a graft extender was used (LbG group, n=20). If an inadequate amount of local bone was present for grafting, a local bone graft with porous hydroxyapatite bone chips was used (LbHa group, n=20). The same amount of demineralized bone matrix was used in both groups. The primary outcome was the relationship between the size of the fusion mass and clinical outcomes in all patients 1 year after surgery. The secondary outcome was a comparison of the size of the fusion mass and clinical outcomes by group.
Results:
The volume of the fusion mass was not correlated with any clinical outcomes 1 year after surgery, either in the overall group of patients or in the subgroup analysis.
Conclusions
The volume of the interbody fusion mass was not related to any clinical outcomes 1 year after surgery. Furthermore, in cases with an insufficient amount of local bone for grafting, porous hydroxyapatite could be a relatively good alternative as a graft extender.

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