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Han-Byeol Park has a total of 17 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Transforaminal Endoscopic Versus Open Lumbar Foraminotomy for Lumbar Foraminal Stenosis: Comparative Two-Year Outcomes and Technical Considerations for Complete Endoscopic Decompression

    by Yong Ahn, Ik-Joon Choi, Sungsoo Bae, Dae-Jean Jo, Seong Son, Han-Byeol Park

    Background/Objectives: Transforaminal endoscopic lumbar foraminotomy (TELF) is increasingly used for lumbar foraminal stenosis, but direct comparisons with open lumbar foraminotomy remain limited. We compared 2-year clinical and perioperative outcomes between the procedures. Methods: We retrospectively reviewed consecutive patients who underwent single-level TELF or open lumbar foraminotomy between January 2020 and January 2024. The primary outcome was the change in leg-pain visual analog scale (VAS) score from baseline to 24 months. Results: Of 159 eligible patients, 147 completed 2-year follow-up (TELF, n = 72; open, n = 75). Improvement in leg-pain VAS score was 5.93 ± 1.60 points after TELF and 5.57 ± 1.44 points after open foraminotomy (mean difference, 0.36; 95% confidence interval, −0.14 to 0.85; p = 0.157). Two-year pain, disability, modified MacNab, complication, and reoperation outcomes did not differ significantly. TELF was associated with a shorter operative time (59.80 ± 15.37 vs. 81.20 ± 21.65 min), hospital stay (1.93 ± 0.68 vs. 6.84 ± 2.85 days), and return-to-work interval among patients who returned to work (3.91 ± 1.20 vs. 8.71 ± 2.45 weeks; all p < 0.001). Conclusions: TELF and open lumbar foraminotomy showed similar observed 2-year clinical outcomes, whereas the TELF treatment pathway was associated with faster perioperative recovery. These observational differences should not be interpreted as equivalence or as effects of surgical technique alone. Complete removal of the medial tip of the superior articular process is presented as a technical consideration for adequate foraminal decompression during TELF; its independent effect on outcomes was not evaluated.

  • Open Access

    Transforaminal Endoscopic Lumbar Foraminotomy for Radiculopathy at the Fused Segment After Lumbar Fusion: Clinical Outcomes and Surgical Considerations

    by Yong Ahn, Han-Byeol Park, Sung-Ho Do, Sojung Lee

    Background: Radiculopathy originating from a previously fused lumbar segment is a clinically relevant but often underrecognized problem. Progressive foraminal stenosis may develop due to postoperative structural changes, leading to mechanical irritation of the exiting nerve root. Transforaminal endoscopic lumbar foraminotomy (TELF) is a minimally invasive option, but its role in this setting is not well defined. Methods: In this retrospective cohort study, we included 36 consecutive patients who underwent TELF for symptomatic foraminal stenosis at a previously fused segment between 2020 and 2023. Clinical outcomes were assessed using the visual analog scale (VAS) for leg pain, Oswestry Disability Index (ODI), and modified MacNab criteria, with follow-up of up to 2 years. Radiographic and intraoperative findings were reviewed to explore the underlying mechanisms. Results: The mean VAS score improved significantly from 8.36 preoperatively to 2.00 at 2 years, and the mean ODI decreased from 70.9% to 16.8%. According to the modified MacNab criteria, 86.1% of the patients achieved excellent or good outcomes. Intraoperative findings revealed fibrotic or hypertrophic foraminal stenosis in 86.1% patients (n = 31), whereas 13.9% of patients (n = 5) showed pedicle screw-related nerve root irritation. Five patients experienced transient postoperative dysesthesia, and no postoperative instability was observed. Conclusions: Radiculopathy at the fused segment is primarily caused by progressive mechanical foraminal compromise after fusion. TELF provides effective symptom relief through direct decompression and may serve as a less invasive alternative to revision fusion in selected patients.


  • Open Access

    Clinical Efficacy of Extended Transforaminal Endoscopic Lumbar Foraminotomy Compared with the Conventional Technique

    by Yong Ahn, Han-Byeol Park, Seong Son, Byung-Rhae Yoo

    Objectives: Transforaminal endoscopic lumbar foraminotomy (TELF) is an emerging minimally invasive surgical technique for lumbar foraminal stenosis. However, its effectiveness is debated because of concerns regarding adequate decompression and its long-term consistency. This study introduced the extended form of TELF, an advanced technique, to provide more extensive decompression using the same approach. Thus, this study aimed to describe the surgical technique and clinical outcomes of this technique. Methods: This retrospective cohort study included patients who underwent conventional (n = 67) or extended (n = 64) TELF. The surgical procedure involved a transforaminal approach with endoscopic decompression, including the removal of the tip of the superior articular process, foraminal ligament, and ligamentum flavum (conventional group), or additional decompression, involving the isthmus and portions of the superior and inferior pedicle walls (extended group). Clinical outcomes were assessed using the visual analog pain scale, Oswestry disability index, and modified Macnab criteria. Results: Despite the longer surgical duration, the extended TELF group tended to show better outcomes in terms of the VAS and ODI scores at the early and final 2-year follow-ups (p < 0.05). The overall success rates were 92.19% and 85.07% in the extended and conventional groups, respectively. No difference was observed in surgical complications between the two groups. Conclusions: Extended TELF, a refined endoscopic technique, achieves better effects than conventional TELF with a lower risk of nerve root irritation by creating a sufficiently safe resection margin. The results support the use of an extended TELF as an advanced form of endoscopic foraminal decompression.


  • Open Access

    Clinical Efficacy of Extended Transforaminal Endoscopic Lumbar Foraminotomy Compared with the Conventional Technique

    by Yong Ahn, Han-Byeol Park, Seong Son, Byung-Rhae Yoo

    Objectives: Transforaminal endoscopic lumbar foraminotomy (TELF) is an emerging minimally invasive surgical technique for lumbar foraminal stenosis. However, its ef-fectiveness is controversial because of concerns regarding adequate decompression and its long-term consistency. This study introduced the extended form of TELF, an ad-vanced technique, to provide more extensive decompression using the same approach. Accordingly, this study aimed to describe the surgical technique and clinical outcomes of this technique. Methods: This retrospective cohort study included patients who un-derwent conventional (n = 67) or extended (n = 64) TELF. The surgical procedure in-volved a transforaminal approach with endoscopic decompression, including the re-moval of the tip of the superior articular process, foraminal ligament, and ligamentum flavum (conventional group), or additional decompression, involving the isthmus and portions of the superior and inferior pedicle walls (extended group). Clinical outcomes were assessed using the visual analog pain scale, Oswestry disability index, and modi-fied Macnab criteria. Results: Despite the longer surgical duration, the extended TELF group tended to show better outcomes in VAS and ODI at the early and final 2-year follow-ups (P < 0.05). The overall success rates were 92.19% (extended group) and 85.07% (conventional group), respectively. No difference was found in surgical complications between the two groups. Conclusions: Extended TELF, a refined endoscopic technique, achieves better effects than conventional TELF with a lower risk of nerve root irritation by creating a sufficiently safe resection margin. The results support the use of an ex-tended TELF as an advanced form of endoscopic foraminal decompression.


  • Open Access

    Comparison of Guided Exercise and Self-Paced Exercise After Lumbar Spine Surgery: A Randomized Controlled Trial

    by Seong Son, Han Byeol Park, Kyeong Sik Kong, Byung Rhae Yoo, Woo Kyung Kim, Jae Ang Sim

    Background: The efficacy of postoperative exercise rehabilitation after spine surgery is controversial, and a protocol for exercise treatment and detailed outcomes based on functional activity have not yet been established. This study aimed to determine the efficacy of exercise rehabilitation after lumbar spine surgery. Methods: A prospective, randomized controlled trial was conducted in 40 patients who underwent lumbar spine surgery (20 patients each in the exercise and control groups) for 12 weeks. Clinical outcomes were assessed using the visual analog scale (VAS) for pain and EuroQol-5 Dimensions 5-Level version (EQ-5D-5L). Body proportions, including body mass index, total muscle mass, and body fat percentage were analyzed. Functional activity was evaluated based on the range of motion of the lumbar spine, strength and endurance of lumbar flexion/extension, flexibility, 6 min walking test, single-leg stance, coordination, and gait pattern analysis. Results: The exercise group showed significantly greater improvement in VAS for pain (66.67% versus 20.00%, p < 0.001) and EQ-5D-5L (45.56% versus 20.00, p = 0.039) compared to the control group. Serial assessment revealed significant improvement in strength of lumbar flexion/extension, 6 min walking test, single-leg stance, coordination, and gait patterns in the exercise group compared to the control group. In particular, the single-leg stance time for the affected leg improved more markedly in the exercise group (280.9% versus 48.7%, p < 0.001). Conclusion: Tailored postoperative exercise after lumbar spine surgery is effective in reducing pain and enhancing functional recovery, including strength and balance.


  • Open Access

    Development of an Exercise Rehabilitation Functional Group for Individualized Exercise After Lumbar Spine Surgery

    by Seong Son, Han Byeol Park, Chan Jong Yoo, Moon-Hee Kim, Byung Rhae Yoo, Jae Ang Sim

    Individualized exercise therapy is crucial for effective postoperative rehabilitation. However, a widely accepted, standardized framework for measuring individual exercise capabilities after lumbar spine surgery (LSS) is lacking. This study aimed to develop a novel Exercise Rehabilitation Functional Group (ERFG) classification system to enable systematic, individualized rehabilitation after LSS. Eight exercise parameters and two clinical factors were assessed in 428 volunteers within 12 weeks of single-segment LSS to establish reference data for the ERFG. The study cohort included 411 participants (mean age 67.10 ± 11.60; 128 males and 283 females) with an average postoperative interval of 42.96 ± 20.25 days. Key metrics included lumbar spine ROM (mean 74.24 ± 25.30°), trunk muscle strength (mean 15.71 ± 5.14 kg), trunk muscle endurance (mean 95.80 ± 35.66 s), whole-body flexibility (mean 3.30 ± 10.65 cm), cardiopulmonary capability (mean 433.91 ± 118.75 m), gait with affected single leg (mean 36.26 ± 5.98%), single-leg balance (median 13.60 s), coordination capability (mean 8.21 ± 3.23 s), EuroQol 5-Dimension 5-Level score (mean 9.39 ± 4.17), and visual analog scale for low back pain (mean 3.78 ± 2.55). Data were categorized into five grades using Cajori’s five-grade mathematical method. Significant correlations were observed between the eight exercise parameters and two clinical factors. This study established a foundational framework for standardizing baseline exercise capabilities after LSS. This ERFG system may provide a basis for individualized rehabilitation strategies to enhance patient outcomes.


  • Open Access

    Comparison of the Efficacy of Zoledronate and Denosumab in Patients with Acute Osteoporotic Vertebral Compression Fractures: A Randomized Controlled Trial

    by Seong Son, Michael Y. Oh, Byung-Rhae Yoo, Han-Byeol Park

    Background: The comparison of the efficacy of zoledronate and denosumab for treating osteoporosis is controversial, and few randomized controlled trials have compared these two drugs in practical patients with acute osteoporotic vertebral compression fractures (OVCFs). We conducted a randomized controlled study to compare the efficacy of zoledronate and denosumab in patients with acute OVCF, with a focus on the occurrence of new OVCF. Methods: We enrolled 206 subjects who had their first acute OVCF, without any previous history of osteoporosis medication. The patients were randomly assigned to receive either intravenous zoledronate once a year or subcutaneous denosumab twice a year. We investigated the OVCF recurrence, clinical outcome, bone mineral density (BMD), and bone turnover markers over 12 months. Results: The final cohort comprised 89 participants (mean age of 75.82 ± 9.34 years, including 74 women [83.15%]) in the zoledronate group and 86 patients (mean age of 75.53 ± 10.23 years, including 71 women [82.56%]) in the denosumab group. New OVCFs occurred in 8 patients (8.89%) in the zoledronate group and 11 patients (12.79%) in the denosumab group (odds ratio, 1.485 [95% confidence interval, 0.567–3.891], p = 0.419). No significant difference was observed in the survival analysis between the two groups (p = 0.407). The clinical outcome, including the visual analog scale score for pain and simple radiographic findings, did not differ between the two groups. The changes in BMD and bone turnover markers were also not significantly different between the two groups. Additionally, drug-related adverse events did not differ between the groups in terms of safety. Conclusions: The efficacy of zoledronate was comparable to that of denosumab in terms of the occurrence of new OVCFs, as well as of the overall clinical course in patients with their first acute OVCF. Notably, this study represents the first comparison of these two drugs in patients with acute OVCF. However, further research with large-scale and long-term follow-up is necessary.


  • Open Access

    Outcome of Percutaneous Endoscopic Lumbar Discectomy in Relation to the Surgeon’s Experience: Propensity Score Matching

    by Seong Son, Michael Y. Oh, Han Byeol Park, Alexander M. Lopez

    Percutaneous endoscopic lumbar discectomy (PELD) presents a challenging learning curve, and the correlation between surgeon experience and clinical outcomes remains contentious. This retrospective study aimed to compare the outcomes of PELD performed by a single surgeon at beginner and experienced stages. Propensity score matching selected 150 patients (75 per group) with a minimum 3-year follow-up. Clinical and radiological outcomes, perioperative complications, and adverse events were assessed. Baseline characteristics, pain improvement, patient satisfaction, and radiological outcomes did not differ between the groups. However, operation time was longer in the beginner group than in the experienced group (57.5 min [IQR, 50.0–70.0] versus 50.0 min [IQR, 45.0–55.0], p < 0.001). The beginner group had higher perioperative complication rates (eight patients [10.7%] versus one patient [1.3%], with a hazard ratio of 8.836 [95% CI, 1.077–72.514], p = 0.034) and lower 3-year survival without adverse events (19 patients [25.3%] in the beginner group and 10 patients [13.3%] in the experienced group, p = 0.045). Our findings indicate that the clinical outcomes were more favorable in patients operated on at the experienced stage compared to those treated at the beginner stage.


  • Open Access

    Transforaminal Endoscopic Lumbar Foraminotomy for Juxta-Fusional Foraminal Stenosis

    by Yong Ahn, Han-Byeol Park

    Adjacent segment foraminal stenosis is a significant adverse event of lumbar fusion. Conventional revision surgery with an extended fusion segment may result in considerable surgical morbidity owing to extensive tissue injury. Transforaminal endoscopic lumbar foraminotomy (TELF) is a minimally invasive surgical approach for symptomatic foraminal stenosis. This study aimed to demonstrate the surgical technique and clinical outcomes of TELF for the treatment of juxta-fusional foraminal stenosis. Full-scale foraminal decompression was performed via a transforaminal endoscopic approach under local anesthesia. A total of 22 consecutive patients who had undergone TELF were evaluated. The included patients had unilateral foraminal stenosis at the juxta-fusional level of the previous fusion surgery, intractable lumbar radicular pain despite at least six months of non-operative treatment, and verified pain focus by imaging and selective nerve root block. The visual analog scale and Oswestry Disability Index scores significantly improved after the two-year follow-up period. The modified MacNab criteria were excellent in six patients (27.27%), good in 12 (55.55%), fair in two (9.09%), and poor in two (9.09%), with a 90.91% symptomatic improvement rate. No significant surgical complications were observed. The minimally invasive TELF is effective for juxta-fusional foraminal stenosis.


  • Open Access

    Safety and Efficacy of Bone Cement (Spinofill®) for Vertebroplasty in Patients with Osteoporotic Compression Fracture : A Preliminary Prospective Study

    by Han Byeol Park, Seong Son, Jong Myung Jung, Sang Gu Lee, Byung Rhae Yoo

    Objective : Although several commercialized bone cements are used during percutaneous vertebroplasty (PVP) for patients with osteoporotic vertebral compression fracture (OVCF), there are no reports using domestic products from South Korea. In this study, we investigated the safety and efficacy of Spinofill® (Injecta Inc., Gunpo, Korea), a new polymethyl methacrylate product.Methods : A prospective, single-center, and single-arm clinical trial of 30 participants who underwent PVP using Spinofill® for painful thoracolumbar OVCF was performed with 6-months follow-up. Clinical and surgical outcomes included the Visual analog scale (VAS), Korean-Oswestry disability index (K-ODI), and Odom’s criteria, complication rate, and recurrence rate. Radiological outcomes were evaluated by measuring the findings of postoperative computed tomography and simple radiograph.Results : The pain of VAS (from 8.95±1.05 to 4.65±2.06, p<0.001) and the life quality based on K-ODI (from 33.95±5.84 to 25.65±4.79, p<0.001) improved significantly, and successful patient satisfaction were achieved in 20 patients (66.7%) 1 day after surgery. These immediate improvements were maintained or more improved during the follow-up. There was no surgery- or product-related complications, but OVCF recurred in two patients (6.7%). Favorable cement interdigitation was reported in 24 patients (80.0%), and extra-vertebral cement leakage was reported in 13 patients (43.0%). The mean vertebral height ratio (from 60.49%±21.97% to 80.07%±13.16%, p<0.001) and segmental kyphotic angle (from 11.46°±8.50° to 7.79°±6.08°, p=0.002) improved one day after surgery. However, these short-term radiological findings somewhat regressed at the end.Conclusion : The overall outcomes of PVP using Spinofill® were as favorable as those of other conventionally used products.