Ho Yeol Zhang

Dr. Ho Yeol Zhang


Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 August 2017 in The Spine Journal
Verified
Journal Article
Closed access
SNSung Hyun Noh
Sung Hyun Noh
HZHo Yeol Zhang
Ho Yeol Zhang
HLHyun Sun Lim
Hyun Sun Lim
HSHyeon Jin Song
Hyeon Jin Song
KYKyung Hwa Yang
Kyung Hwa Yang

25 January 2018 in BMC Musculoskeletal Disorders
Verified
Journal Article
Open access
PDF file
SNSung Hyun Noh
Sung Hyun Noh
HZHo Yeol Zhang
Ho Yeol Zhang
We intended to analyze the efficacy of a new integrated cage and plate device called Perfect-C for anterior cervical discectomy and fusion (ACDF) to cure single-level cervical degenerative disc disease. We enrolled 148 patients who were subjected to single-level ACDF with one of the following three surgical devices: a Perfect-C implant (41 patients), a Zero-P implant (36 patients), or a titanium plate with a polyetheretherketone (PEEK) cage (71 patients). We conducted a retrospective study to compare the clinical and radiological results among the three groups. The length of the operation, intraoperative blood loss, and duration of hospitalization were significantly lower in the Perfect-C group than in the Zero-P and plate-with-cage groups (P < 0.05). At the last follow-up visit, heterotopic ossification (HO) was not observed in any cases (0%) in the Perfect-C and Zero-P groups but was noted in 21 cases (30%) in the plate-with-cage group. The cephalad and caudal plate-to-disc distance (PDD) and the cephalad and caudal PDD/anterior body height (ABH) were significantly greater in the Perfect-C and Zero-P groups than in the plate-with-cage group (P < 0.05). Subsidence occurred in five cases (14%) in the Perfect-C group, in nine cases (25%) in the Zero-P group, and in 15 cases (21%) in the plate-with-cage group. Fusion occurred in 37 cases (90%) in the Perfect-C group, in 31 cases (86%) in the Zero-P group, and in 68 cases (95%) in the plate-with-cage group. The Perfect-C, Zero-P, and plate-with-cage devices are effective for treating single-level cervical degenerative disc disease. However, the Perfect-C implant has many advantages over both the Zero-P implant and conventional plate-cage treatments. The Perfect-C implant was associated with shorter operation times and hospitalization durations, less blood loss, and lower subsidence rates compared with the Zero-P implant or the titanium plate with a PEEK cage.

21 February 2023 in Bioengineering
Verified
Journal Article
Open access
PDF file
HZHo Yeol Zhang
Ho Yeol Zhang
SSSeong Son
Seong Son
BYByung Rhae Yoo
Byung Rhae Yoo
TYTae-Mi Youk
Tae-Mi Youk
Digital infrared thermographic imaging (DITI) is a supplementary diagnostic technique to visualize the surface temperature of the human body. However, there is currently no reference standard for the lower limbs for accurate diagnosis. In this study, we performed DITI on the lower limbs of 905 healthy Korean volunteers (411 males and 494 females aged between 20 and 69 years) to obtain reference standard data. Thermography was conducted on the front, back, lateral sides, and sole area, and 188 regions of interest (ROIs) were analyzed. Additionally, subgroup analysis was conducted according to the proximity of ROIs, sex, and age groups. The mean temperatures of ROIs ranged from 24.60 ± 5.06 to 28.75 ± 5.76 °C and the absolute value of the temperature difference between both sides reached up to 1.06 ± 2.75 °C. According to subgroup analysis, the sole area had a significantly lower temperature than any other areas, men had higher temperatures than women, and the elderly had higher temperatures than the young adults except for the 20s age group (p < 0.001, respectively). This result could be used as a foundation for the establishment of a reference standard for DITI. Practical patient DITI can be accurately interpreted using these data, and it can serve as a basis for further scientific research.

1 January 2009 in Journal of Korean Neurosurgical Society
Verified
Journal Article
Open access
PDF file
HZHo Yeol Zhang
Ho Yeol Zhang
JPJeong Yoon Park
Jeong Yoon Park
BCBo Young Cho
Bo Young Cho
This study examines whether functional motion is present at one or more years after Bioflex System placement. BioFlex System is a flexible rod system which has been used to preserve motion at the area of implantation. There has not been a scientific study showing how much motion is preserved after implantation. A total of 12 consecutive patients underwent posterior dynamic stabilization using the BioFlex System. Six patients were treated using a L3-4-5 construct and other six patients using a L4-5-S1 construct. Follow-up ranged from 12 to 33 months and standing neutral lateral, extension, flexion and posteroanterior (PA) radiographs were obtained at 3, 6, 9, and 12 months and at more than 12 months postoperatively. Range of motion (ROM), whole lumbar lordosis, and ROMs of motion segments from L2 to S1 were determined. Patients with a L3-4-5 construct demonstrated a decrease in mean ROM for whole lumbar decreased from 40.08 to 30.77. Mean ROM for L3-4 (6.12 to 2.20) and L4-5 (6.55 to 1.67) also decreased after one year. Patients with a L4-5-S1 construct demonstrated L4-5 (8.75 to 2.70) and L5-S1 (9.97 to 3.25) decrease of mean ROM at one year postoperatively. Lumbar lordosis was preserved at both L3-4-5 and L4-5-S1 constructs. Clinical results showed significant improvements in both study groups. The present study provides preliminary information regarding the BioFlex motion preservation system. We conclude that the BioFlex System preserves functional motion to some degree at instrumented levels. However, although total lumbar lordosis was preserved, ROMs at implantation segments were lower than preoperative values.

1 January 2020 in Yonsei Medical Journal
Verified
Journal Article
Open access
YCYoung Soo Chung
Young Soo Chung
HZHo Yeol Zhang
Ho Yeol Zhang
YHYoon Ha
Yoon Ha
JPJeong-Yoon Park
Jeong-Yoon Park
This study aimed to predict the surgical outcomes of diffuse idiopathic skeletal hyperostosis (DISH)-related dysphagia (DISH-phagia) and to evaluate the importance of prevertebral soft tissue thickness (PVST). In total, 21 surgeries (anterior osteophytectomy or anterior cervical decompression and fixation) were included in this study for DISH-phagia from 2003 to 2019. Clinical outcomes were assessed using the Dysphagia Outcome and Severity Scale (DOSS) preoperatively, at 1 month postoperatively, and last follow up (mean 29.5 months). PVST was measured using lateral plain radiographs. Paired t-test and Spearman's correlation test was used to identify relationships between various PVST indices and DOSS. Comparisons were made from 17 patients out of 21, in which the record had all of three measurements. The narrowest PVST preoperatively was 2.55±0.90 mm, with a DOSS score of 4.47±1.61, and that at 1 month after surgery was 5.02±2.33 mm, with a DOSS score of 6.12±1.32. At last follow up, PVST and DOSS values were 3.78±0.92 mm and 5.82±1.34, and three patients experienced symptom relapse. Significant relationships were found between PVST and DOSS at all time points: before surgery (R=0.702, p<0.001), 1 month after surgery (R=0.539, p=0.012), and last follow up (R=0.566, p=0.020). Surgical removal of anterior osteophytes is an effective treatment option for DISH-phagia, and PVST is a useful parameter in DISH-phagia. The goal of DISH surgery should be to remove DISH as much as possible to ensure sufficient PVST postoperatively.

28 November 2018 in Quantitative InfraRed Thermography Journal
Verified
Journal Article
Closed access
DKDong Wook Kim
Dong Wook Kim
HZHo Yeol Zhang
Ho Yeol Zhang
JYJee-Hyoung Yoo
Jee-Hyoung Yoo
YPYoon Soo Park
Yoon Soo Park
HSHyeon Jin Song
Hyeon Jin Song
KYKyung Hwa Yang
Kyung Hwa Yang
Facial temperature measurements using infrared thermography (IRT) will be allowed screening travellers with high fever quickly and safely at airports or national borders if we have the formula for calculating tympanic temperature or reference standard temperature tables. This study was conducted to investigate whether the recommended position in the ISO guidelines for facial themograms measured by IRT best reflects tympanic temperature or whether other specific areas are better represented. Data were collected from NHIS Ilsan Hospital from August 2016 to December 2016. A total of 508 subjects were included in this study. The six regions of interest (ROI) of eye (medial canthus, cornea, sclera between medial canthus and cornea both side) and one ROI of inter-brow of face were defined, (as shown in figure 1) where the temperatures were measured. These values were compared with the eardrum temperature. The results showed that the tympanic membrane temperature and medial canthus were the most similar. And a model to predict tympanic temperature through statistical bias correction can be developed.