1.L-Point Entry, Juxtapedicular, and Endplate-Parallel Trajectory (L-JET) Screw Fixation: A Novel Technique in Thoracic Spinal Tumor Surgery
Seunghoon LEE ; Young Rak KIM ; Chang-Hyun LEE ; Jungbo SIM ; Woojin KIM ; Ho Sung MYEONG ; Hangeul PARK ; Jun-Hoe KIM ; Chi Heon KIM
Journal of Minimally Invasive Spine Surgery and Technique 2026;11(1):6-13
Objective:
Thoracic pedicle screw fixation is technically demanding because of the natural variability in pedicle anatomy, a challenge that is further exacerbated in patients with spinal tumors who often have compromised pedicles. The L-point entry, juxtapedicular, and endplate-parallel trajectory (L-JET) technique was developed to provide a uniform entry point, a predictable screw trajectory, and the capacity to accommodate larger-diameter screws at levels T3–10. This study aimed to evaluate the safety and feasibility of the L-JET technique in comparison with the conventional transpedicular method.
Methods:
A comparative analysis of consecutively collected data was performed to evaluate outcomes associated with the L-JET technique in patients undergoing surgery for thoracic extradural spinal tumors. The L-point was defined as the intersection of a vertical line along the lateral margin of the facet joint and a horizontal line along the upper edge of the transverse process. The screw trajectory was planned with 30° of medial convergence in the axial plane, creating a juxtapedicular path, and a straightforward trajectory in the sagittal plane. Primary outcome measures included screw diameter, screw length, cortical breach rate, and the need for revision surgery, as assessed using computed tomography scans and medical records.
Results:
A total of 108 screws were placed in 22 patients using the L-JET technique, while 98 screws were placed in 18 patients using the conventional technique. The L-JET group used significantly larger-diameter screws (6.06±0.65 mm) than the conventional group (5.74±0.80 mm, p=0.02), with no significant difference observed in screw length between groups. Medial cortical breach occurred in one screw in each group, and no supra- or infrapedicular breaches were identified. No screw-related neurovascular complications or revision surgeries occurred in either group.
Conclusion
The L-JET technique enables consistent screw placement with larger-diameter screws, even in compromised pedicles associated with thoracic spinal tumors, without increasing the risk of complications or the need for revision surgery.
2.Identification of de novo BSCL2 Asn88Ser Variant with Atypical Presentation of Distal Hereditary Motor Neuropathy Type 5: Clinical Challenge in Diagnosis of Motor Neuron Diseases
Hyunkee KIM ; Jung Hyun LEE ; Dongju WON ; Jong Rak CHOI ; Ha Young SHIN ; Seung Hyun KIM
Journal of the Korean Neurological Association 2025;43(1):35-39
Diagnosing amyotrophic lateral sclerosis (ALS) is challenging and requires distinguishing it from conditions like distal hereditary motor neuropathy type 5 (dHMN-V). A 21-year-old female initially diagnosed with ALS showed progressive upper limb weakness extending to the lower limbs. Trio exome sequencing revealed a de novo pathogenic Berardinelli-Seip congenital lipodystrophy 2 variant (c.263A>G, p.Asn88Ser), confirming dHMN-V. Minipolymyoclonus of small amplitudes in bilateral wrists and ankles was an atypical presentation. This case underscores the importance of considering dHMN-V as a differential diagnosis in ALS-like distal upper extremity weakness.
3.Identification of de novo BSCL2 Asn88Ser Variant with Atypical Presentation of Distal Hereditary Motor Neuropathy Type 5: Clinical Challenge in Diagnosis of Motor Neuron Diseases
Hyunkee KIM ; Jung Hyun LEE ; Dongju WON ; Jong Rak CHOI ; Ha Young SHIN ; Seung Hyun KIM
Journal of the Korean Neurological Association 2025;43(1):35-39
Diagnosing amyotrophic lateral sclerosis (ALS) is challenging and requires distinguishing it from conditions like distal hereditary motor neuropathy type 5 (dHMN-V). A 21-year-old female initially diagnosed with ALS showed progressive upper limb weakness extending to the lower limbs. Trio exome sequencing revealed a de novo pathogenic Berardinelli-Seip congenital lipodystrophy 2 variant (c.263A>G, p.Asn88Ser), confirming dHMN-V. Minipolymyoclonus of small amplitudes in bilateral wrists and ankles was an atypical presentation. This case underscores the importance of considering dHMN-V as a differential diagnosis in ALS-like distal upper extremity weakness.
4.Identification of de novo BSCL2 Asn88Ser Variant with Atypical Presentation of Distal Hereditary Motor Neuropathy Type 5: Clinical Challenge in Diagnosis of Motor Neuron Diseases
Hyunkee KIM ; Jung Hyun LEE ; Dongju WON ; Jong Rak CHOI ; Ha Young SHIN ; Seung Hyun KIM
Journal of the Korean Neurological Association 2025;43(1):35-39
Diagnosing amyotrophic lateral sclerosis (ALS) is challenging and requires distinguishing it from conditions like distal hereditary motor neuropathy type 5 (dHMN-V). A 21-year-old female initially diagnosed with ALS showed progressive upper limb weakness extending to the lower limbs. Trio exome sequencing revealed a de novo pathogenic Berardinelli-Seip congenital lipodystrophy 2 variant (c.263A>G, p.Asn88Ser), confirming dHMN-V. Minipolymyoclonus of small amplitudes in bilateral wrists and ankles was an atypical presentation. This case underscores the importance of considering dHMN-V as a differential diagnosis in ALS-like distal upper extremity weakness.
5.Reaching New Heights: A Comprehensive Study of Hand Transplantations in Korea after Institutionalization of Hand Transplantation Law
Yo Han KIM ; Yun Rak CHOI ; Dong Jin JOO ; Woo Yeol BAEK ; Young Chul SUH ; Won Taek OH ; Jae Yong CHO ; Sang Chul LEE ; Sang Kyum KIM ; Hyang Joo RYU ; Kyung Ock JEON ; Won Jai LEE ; Jong Won HONG
Yonsei Medical Journal 2024;65(2):108-119
Purpose:
With the revision of the Organ and Transplantation Act in 2018, the hand has become legal as an area of transplantable organs in Korea. In January 2021, the first hand allotransplantation since legalization was successfully performed, and we have performed a total of three successful hand transplantation since then. By comparing and incorporating our experiences, this study aimed to provide a comprehensive reconstructive solution for hand amputation in Korea.
Materials and Methods:
Recipients were selected through a structured preoperative evaluation, and hand transplantations were performed at the distal forearm level. Postoperatively, patients were treated with three-drug immunosuppressive regimen, and functional outcomes were monitored.
Results:
The hand transplantations were performed without intraoperative complications. All patients had partial skin necrosis and underwent additional surgical procedures in 2 months after transplantation. After additional operations, no further severe complications were observed. Also, patients developed acute rejection within 3 months of surgery, but all resolved within 2 weeks after steroid pulse therapy. Motor and sensory function improved dramatically, and patients were very satisfied with the appearance and function of their transplanted hands.
Conclusion
Hand transplantation is a viable reconstructive option, and patients have shown positive functional and psychological outcomes. Although this study has limitations, such as the small number of patients and short follow-up period, we should focus on continued recovery of hand function, and be careful not to develop side effects from immunosuppressive drugs. Through the present study, we will continue to strive for a bright future regarding hand transplantation in Korea.
6.Radiologic Outcomes of Plantar Plate Repair through a Plantar Approach for the Dislocated Metatarsophalangeal Joint of the Lesser Toe
Chang Hyun DOH ; Sunghoo KIM ; Young-Rak CHOI ; Ho Seong LEE
Clinics in Orthopedic Surgery 2024;16(6):1001-1009
Background:
: A torn plantar plate (PP) is important pathologic anatomy related to a dislocated or subluxated metatarsophalangeal joint (MTPJ). Traditionally, a torn PP was treated with Weil osteotomy through a dorsal approach. However, because of the limited visualization of the dorsal approach, PP repair through a plantar approach has been proposed as a new technique. This study aimed to radiologically evaluate the outcome of PP repair through the plantar approach using an improved MTPJ overlap distance (MOD) on an anteroposterior view and the degree of subluxation on an oblique view. We also aimed to investigate the potential factors affecting the recurrence of MTPJ instability.
Methods:
In this study, we included 31 patients who had a subluxated or dislocated MTPJ of the second or third toe and underwent surgical PP repair. PP repair was performed via a plantar approach after shortening metatarsal (MT) osteotomy with a dorsal approach for longer MT bone. We assessed the severity of MTPJ subluxation by measuring the MOD and subluxation subtype on radiographs. Radiologic recurrence was defined as an increase in MOD or change from subluxation type A to subluxation type B.The relationship of recurrence with clinical and radiologic factors was evaluated by comparing the recurred group against the nonrecurred group.
Results:
Shortening MT osteotomy was performed in 26 of 31 cases (84%). Repeated measures analysis of variance comparing preoperation, pin removal, and the latest follow-up MOD values revealed the effectiveness of PP repair through the plantar approach (p < 0.001). The MOD did not significantly change after pin removal and the latest follow-up (p = 0.130), indicating that reduction was well maintained. None of the clinical and radiologic factors were significantly related to recurrence. However, 3 of 12 rheumatoid arthritis (RA) feet (25%) recurred and 3 of 5 recurred cases (60%) were RA feet. This result suggests that RA indicated a tendency for recurrence.
Conclusions
PP repair through the plantar approach has the advantage of excellent visualization of a torn PP and direct repair.We, therefore, recommend using the plantar approach for PP repair of the MTPJ.
7.Radiologic Outcomes of Plantar Plate Repair through a Plantar Approach for the Dislocated Metatarsophalangeal Joint of the Lesser Toe
Chang Hyun DOH ; Sunghoo KIM ; Young-Rak CHOI ; Ho Seong LEE
Clinics in Orthopedic Surgery 2024;16(6):1001-1009
Background:
: A torn plantar plate (PP) is important pathologic anatomy related to a dislocated or subluxated metatarsophalangeal joint (MTPJ). Traditionally, a torn PP was treated with Weil osteotomy through a dorsal approach. However, because of the limited visualization of the dorsal approach, PP repair through a plantar approach has been proposed as a new technique. This study aimed to radiologically evaluate the outcome of PP repair through the plantar approach using an improved MTPJ overlap distance (MOD) on an anteroposterior view and the degree of subluxation on an oblique view. We also aimed to investigate the potential factors affecting the recurrence of MTPJ instability.
Methods:
In this study, we included 31 patients who had a subluxated or dislocated MTPJ of the second or third toe and underwent surgical PP repair. PP repair was performed via a plantar approach after shortening metatarsal (MT) osteotomy with a dorsal approach for longer MT bone. We assessed the severity of MTPJ subluxation by measuring the MOD and subluxation subtype on radiographs. Radiologic recurrence was defined as an increase in MOD or change from subluxation type A to subluxation type B.The relationship of recurrence with clinical and radiologic factors was evaluated by comparing the recurred group against the nonrecurred group.
Results:
Shortening MT osteotomy was performed in 26 of 31 cases (84%). Repeated measures analysis of variance comparing preoperation, pin removal, and the latest follow-up MOD values revealed the effectiveness of PP repair through the plantar approach (p < 0.001). The MOD did not significantly change after pin removal and the latest follow-up (p = 0.130), indicating that reduction was well maintained. None of the clinical and radiologic factors were significantly related to recurrence. However, 3 of 12 rheumatoid arthritis (RA) feet (25%) recurred and 3 of 5 recurred cases (60%) were RA feet. This result suggests that RA indicated a tendency for recurrence.
Conclusions
PP repair through the plantar approach has the advantage of excellent visualization of a torn PP and direct repair.We, therefore, recommend using the plantar approach for PP repair of the MTPJ.
8.Joint-Preserving Surgery for Hallux Valgus Deformity in Rheumatoid Arthritis
Seung-Hwan PARK ; Young Rak CHOI ; Jaehyung LEE ; Chang Hyun DOH ; Ho Seong LEE
Clinics in Orthopedic Surgery 2024;16(3):461-469
Background:
Rheumatoid arthritis (RA) is a chronic autoimmune disorder that frequently causes forefoot deformities. Arthrodesis of the first metatarsophalangeal joint is a common surgery for severe hallux valgus. However, joint-preserving surgery can maintain the mobility of the joint. This study aimed to investigate the clinical and radiographic outcomes of distal chevron metatarsal osteotomy (DCMO) for correcting hallux valgus deformity associated with RA.
Methods:
Between August 2000 and December 2018, 18 consecutive patients with rheumatoid forefoot deformities (24 feet) underwent DCMO for hallux valgus with/without lesser toe surgery. Radiological evaluations were conducted, assessing the hallux valgus angle, the intermetatarsal angle between the first and second metatarsals, and the Sharp/van der Heijde score for erosion and joint space narrowing. Clinical outcomes were quantified using a visual analog scale for pain and the American Orthopaedic Foot and Ankle Society forefoot scores to measure function and alignment.
Results:
The mean hallux valgus angle decreased from 38.0° (range, 25°–65°) preoperatively to 3.5° (range, 0°–17°) at the final follow-up (p < 0.05). The mean intermetatarsal angle decreased from 14.9° (range, 5°–22°) preoperatively to 4.3° (range, 2°–11°) at the final follow-up. (p < 0.05). Regarding the Sharp/van der Heijde score, the mean erosion score (0–10) showed no significant change, decreasing from 3.83 (range, 0–6) preoperatively to 3.54 (range, 0–4) at the final follow-up (p = 0.12). Recurrent hallux valgus was observed in 1 patient and postoperative hallux varus deformity was observed in 2 feet. Spontaneous fusion of the metatarsophalangeal joint developed in 1 case.
Conclusions
DCMO resulted in satisfactory clinical and radiographic outcomes for correcting RA-associated hallux valgus deformity.
9.Radiologic Outcomes of Plantar Plate Repair through a Plantar Approach for the Dislocated Metatarsophalangeal Joint of the Lesser Toe
Chang Hyun DOH ; Sunghoo KIM ; Young-Rak CHOI ; Ho Seong LEE
Clinics in Orthopedic Surgery 2024;16(6):1001-1009
Background:
: A torn plantar plate (PP) is important pathologic anatomy related to a dislocated or subluxated metatarsophalangeal joint (MTPJ). Traditionally, a torn PP was treated with Weil osteotomy through a dorsal approach. However, because of the limited visualization of the dorsal approach, PP repair through a plantar approach has been proposed as a new technique. This study aimed to radiologically evaluate the outcome of PP repair through the plantar approach using an improved MTPJ overlap distance (MOD) on an anteroposterior view and the degree of subluxation on an oblique view. We also aimed to investigate the potential factors affecting the recurrence of MTPJ instability.
Methods:
In this study, we included 31 patients who had a subluxated or dislocated MTPJ of the second or third toe and underwent surgical PP repair. PP repair was performed via a plantar approach after shortening metatarsal (MT) osteotomy with a dorsal approach for longer MT bone. We assessed the severity of MTPJ subluxation by measuring the MOD and subluxation subtype on radiographs. Radiologic recurrence was defined as an increase in MOD or change from subluxation type A to subluxation type B.The relationship of recurrence with clinical and radiologic factors was evaluated by comparing the recurred group against the nonrecurred group.
Results:
Shortening MT osteotomy was performed in 26 of 31 cases (84%). Repeated measures analysis of variance comparing preoperation, pin removal, and the latest follow-up MOD values revealed the effectiveness of PP repair through the plantar approach (p < 0.001). The MOD did not significantly change after pin removal and the latest follow-up (p = 0.130), indicating that reduction was well maintained. None of the clinical and radiologic factors were significantly related to recurrence. However, 3 of 12 rheumatoid arthritis (RA) feet (25%) recurred and 3 of 5 recurred cases (60%) were RA feet. This result suggests that RA indicated a tendency for recurrence.
Conclusions
PP repair through the plantar approach has the advantage of excellent visualization of a torn PP and direct repair.We, therefore, recommend using the plantar approach for PP repair of the MTPJ.
10.Radiologic Outcomes of Plantar Plate Repair through a Plantar Approach for the Dislocated Metatarsophalangeal Joint of the Lesser Toe
Chang Hyun DOH ; Sunghoo KIM ; Young-Rak CHOI ; Ho Seong LEE
Clinics in Orthopedic Surgery 2024;16(6):1001-1009
Background:
: A torn plantar plate (PP) is important pathologic anatomy related to a dislocated or subluxated metatarsophalangeal joint (MTPJ). Traditionally, a torn PP was treated with Weil osteotomy through a dorsal approach. However, because of the limited visualization of the dorsal approach, PP repair through a plantar approach has been proposed as a new technique. This study aimed to radiologically evaluate the outcome of PP repair through the plantar approach using an improved MTPJ overlap distance (MOD) on an anteroposterior view and the degree of subluxation on an oblique view. We also aimed to investigate the potential factors affecting the recurrence of MTPJ instability.
Methods:
In this study, we included 31 patients who had a subluxated or dislocated MTPJ of the second or third toe and underwent surgical PP repair. PP repair was performed via a plantar approach after shortening metatarsal (MT) osteotomy with a dorsal approach for longer MT bone. We assessed the severity of MTPJ subluxation by measuring the MOD and subluxation subtype on radiographs. Radiologic recurrence was defined as an increase in MOD or change from subluxation type A to subluxation type B.The relationship of recurrence with clinical and radiologic factors was evaluated by comparing the recurred group against the nonrecurred group.
Results:
Shortening MT osteotomy was performed in 26 of 31 cases (84%). Repeated measures analysis of variance comparing preoperation, pin removal, and the latest follow-up MOD values revealed the effectiveness of PP repair through the plantar approach (p < 0.001). The MOD did not significantly change after pin removal and the latest follow-up (p = 0.130), indicating that reduction was well maintained. None of the clinical and radiologic factors were significantly related to recurrence. However, 3 of 12 rheumatoid arthritis (RA) feet (25%) recurred and 3 of 5 recurred cases (60%) were RA feet. This result suggests that RA indicated a tendency for recurrence.
Conclusions
PP repair through the plantar approach has the advantage of excellent visualization of a torn PP and direct repair.We, therefore, recommend using the plantar approach for PP repair of the MTPJ.

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