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Featured researches published by Dong Hoon Lee.


Arthroscopy | 2011

Arthroscopic Suture Anchor Repair Versus Pullout Suture Repair in Posterior Root Tear of the Medial Meniscus: A Prospective Comparison Study

Jae-Hwa Kim; Ju-Hwan Chung; Dong Hoon Lee; Yoon Seok Lee; Jung-Ryul Kim; Keun-Jung Ryu

PURPOSE To evaluate functional and radiographic results of arthroscopic suture anchor repair for posterior root tear of the medial meniscus (PRTMM) and compare with pullout suture repair. METHODS From December 2006 to August 2008, 51 consecutive patients underwent arthroscopic repair of PRTMM at our hospital. The repair technique was switched over time from pullout suture repair (group 1) to suture anchor repair (group 2). Of the patients, 6 were lost to follow-up, leaving a study population of 45 patients, with 22 menisci (48.9%) in group 1 and 23 (51.1%) menisci in group 2. The mean follow-up duration was 25.9 months (range, 24 to 27 months) in group 1 and 26.8 months (range, 24 to 28 months) in group 2. Compared variables included International Knee Documentation Committee criteria, Kellgren-Lawrence grade, gap distance at PRTMM, structural healing, meniscal extrusion, and cartilage degeneration of the medial femoral condyle. RESULTS At 2 years postoperatively, both groups showed significant improvements in function (P < .05) and did not show significant differences in Kellgren-Lawrence grade (P > .05) compared with preoperatively. On magnetic resonance imaging, the gap distance at PRTMM was 3.2 ± 1.1 mm in group 1 and 2.9 ± 0.9 mm in group 2 preoperatively (P > .05). Complete structural healing was seen in 11 cases in group 1 and 12 cases in group 2 (P > .05). Mean meniscal extrusion of 4.3 ± 0.9 mm (group 1) and 4.1 ± 1.0 mm (group 2) preoperatively was significantly decreased to 2.1 ± 1.0 mm (group 1) and 2.2 ± 0.8 mm (group 2) postoperatively (P < .05). Regardless of repair technique, incompletely healed cases showed progression of cartilage degeneration (4 cases in group 1 and 2 cases in group 2). CONCLUSIONS For PRTMM, our results show significant functional improvement in both the suture anchor repair and pullout suture repair groups. Reduction of meniscal extrusion seems to be appropriate to preserve its protective role against progression of cartilage degeneration after complete healing at PRTMM. LEVEL OF EVIDENCE Level III, prospective therapeutic comparative study.


Biomolecules & Therapeutics | 2012

A Comparison between Water and Ethanol Extracts of Rumex acetosa for Protective Effects on Gastric Ulcers in Mice

Ji Yeong Bae ; Yoon-Seok Lee; Sun Young Han ; Eun Ju Jeong; Mi Kyeong Lee; Jae Yang Kong ; Dong Hoon Lee; Kyeong Jae Cho ; Haeng Soon Lee ; Mi Jeong Ahn

Rumex acetosa is a perennial herb that is widely distributed across eastern Asia. Although the hot water extract of R. acetosa has been used to treat gastritis or gastric ulcers as a folk medicine, no scientific report exists for the use of this plant to treat gastric ulcers. Hence, the present study was undertaken to assess the anti-ulcer activity of water and 70% ethanol extracts obtained from R. acetosa, using an HCl/ethanol-induced gastric ulcer model in mice. Anti-inflammatory and free radical-scavenging activities of these two extracts were also evaluated and compared. As a result, the administration of R. acetosa extracts significantly reduced the occurrence of gastric ulcers. However, significant differences in protective activity against gastric ulcers were observed between the two samples. In the case of the group pretreated with an ethanol extract dosage of 100 mg/kg, the protective effect (90.9%) was higher than that of water extract (41.2%). Under histological evaluation, pretreatment with R. acetosa extracts reversed negative effects, such as inflammation, edema, moderate hemorrhaging and loss of epithelial cells, presented by HCl/ ethanol-treated stomachs. Meanwhile, R. acetosa extracts showed potent DPPH radical-scavenging activity and decreased NO production in a murine macrophage cell line, RAW 264.7, in a dose-dependent manner without affecting cellular viability. The greater anti-ulcer and NO production inhibitory activities exhibited by ethanol extracts compared to water extracts could be ascribed to the higher emodin levels, a major anthraquinone component of this plant.


Clinical Orthopaedics and Related Research | 2016

Reamed Intramedullary Nailing has an Adverse Effect on Bone Regeneration During the Distraction Phase in Tibial Lengthening.

Keun Jung Ryu; Bang Hyun Kim; Jin Ho Hwang; Hyunwoo Kim; Dong Hoon Lee

BackgroundThe lengthening over nail (LON) technique has gained popularity because it enables shorter periods of external fixation, prevents deformities during lengthening, and reduces the risk of refracture after removal of the frame compared with the classic Ilizarov method. However, it is not clear if the violation of endosteal blood supply by reamed intramedullary nailing in the LON technique has a negative effect on bone regeneration or a positive effect by compensatory enhancement of periosteal circulation.Questions/purposesThe purposes of this study were to (1) compare the amount of regenerate bone during the distraction phase between two tibial lengthening techniques, the LON technique and lengthening and then nail (LATN) technique; and (2) compare callus shape at the end of the distraction phase using the classification of Li et al.MethodsThis is a retrospective study comparing two treatment groups. Between September 2011 and June 2013, 120 patients underwent bilateral lower leg lengthening for familial short stature with either the LON or LATN technique, and were considered potentially eligible for inclusion in this retrospective, comparative study. During this same period, LON and LATN techniques were used in other patient populations, but all patients with familial short stature were considered for inclusion in the study. The specific contraindications for LON were diameter of the isthmus of the tibia narrower than 8 mm, length of the tibia shorter than 270 mm, and alignment of the lower extremity in valgus; in patients without these specific contraindications to LON, patients were offered either LATN or LON after counseling regarding the advantages and disadvantages of each procedure. The proposed advantages of LATN were shorter healing index and more stable internal fixation which might lead to earlier full weightbearing, whereas proposed disadvantages were a greater chance for deep infection, more deformity during lengthening, and subsequently longer external fixator period for correction. The groups were comparable in terms of age, sex distribution, smoking history, BMI, distraction rate, and final length gain. A longer period of external fixation was necessary in the LATN group, related to the relative stability of the segment without an intramedullary nail. Patients with tibial lengthening with the LON technique (31 patients, 62 tibiae) were compared with patients who had the LATN technique (89 patients, 178 tibiae) regarding the amount of bone regeneration at the anterior, posterior, medial, and lateral cortices of the lengthened area for each at 4, 8, and 12 weeks postoperatively using a pixel value ratio method. In addition, both groups were compared for callus shape and type at the end of the distraction phase (LON, 3.4 ± 0.06 months; LATN, 4.2 ± 0.05 months).ResultsThe pixel value ratios of the anterior, posterior, medial, and lateral cortices in the LON and LATN groups were 0.78 ± 0.06 and 0.74 ± 0.05; 0.82 ± 0.08 and 0.76 ± 0.05; 0.75 ± 0.06 and 0.72 ± 0.05; and 0.85 ± 0.06 and 0.82 ± 0.06, respectively at 4 weeks postoperatively(p value > 0.500 for all); 0.75 ± 0.05 and 0.77 ± 0.04; 0.78 ± 0.05 and 0.89 ± 0.04; 0.73 ± 0.05 and 0.82 ± 0.05; and 0.78 ± 0.06 and 0.88 ± 0.03, respectively at 8 weeks postoperatively (p value < 0.001 for the posterior, medial, and lateral cortices); 0.72 ± 0.05 and 0.76 ± 0.03; 0.75 ± 0.07 and 0.89 ± 0.03; 0.71 ± 0.05 and 0.82 ± 0.03; and 0.78 ± 0.06 and 0.91 ± 0.03, respectively at 12 weeks postoperatively (p value < 0.001 for the posterior, medial, and lateral cortices). A greater percentage of tibiae having the generally favored fusiform-shaped callus were seen with the LATN technique (61 of 178 segments) than with the LON technique (four of 62 segments; p < 0.001). There were no tibia showing the inferior concave, lateral, or central-shaped callus with the LATN technique, whereas eight tibiae (eight of 62 segments) showed concave-shaped callus with the LON technique (p < 0.001).ConclusionsThe potentially negative effect on callus regeneration from the concomitant use of reamed intramedullary nailing during the LON technique should not be overlooked. Based on our study, LATN may be a better choice for patients willing to accept the longer period of external fixation.Level of EvidenceLevel III, therapeutic study.


Clinical Orthopaedics and Related Research | 2016

Is there an Increase in Valgus Deviation in Tibial Distraction Using the Lengthening Over Nail Technique

Hoon Park; Keun Jung Ryu; Hyunwoo Kim; Jin Ho Hwang; Joon Woo Han; Dong Hoon Lee

BackgroundDuring tibial lengthening, the soft tissues of the posterolateral compartment produce distraction-resisting forces causing valgus angulation. Although this occurs with the classic Ilizarov method, whether a valgus deformity develops with the lengthening over nail (LON) technique is questioned, because the intramedullary nail is thought to resist deforming forces and adequately maintain alignment of the distracted bone.Questions/purposesThe purposes of this study were to (1) determine the amount of valgus deviation during tibial lengthening with the LON technique; and (2) analyze the factors that may be associated with valgus deviation with the LON technique.MethodsBetween June 2009 and September 2013, we performed 346 tibial lengthenings using the LON technique, lengthening and then nail technique, or lengthening with an intramedullary lengthening device. Sixty patients (120 tibias) who underwent bilateral lower leg lengthening with the LON technique were enrolled in this retrospective study. To limit the number of variables, we analyzed only the right tibia in all patients (60 tibias). The mean followup was 42 months (range, 26–71 months). The mean age of the patients was 25 years (range, 18–40 years). There were 36 male and 24 female patients. The mean final length gain was 67 ± 9 mm. The mean time for distraction was 100 ± 25 days. The overall valgus deviation was assessed by measuring the change in the medial proximal tibial angle and mechanical femorotibial angle on radiographs obtained before and after surgery and after completion of lengthening. Several demographic, surgical, and distraction-related variables were considered possible factors to prevent valgus deviation: proximal fixation method; presence of a blocking screw; diameter and length of the intramedullary nail; degree of nail insertion; length of the nail in the distal segment after completion of distraction; final length gain; and patient’s BMI. During the period studied, the blocking screw was to maintain the mechanical axis in patients who had neutral or valgus alignment preoperatively, or to prevent more valgus change in patients who underwent acute correction of varus deformity intraoperatively. Uni- and multivariate analyses were conducted.ResultsValgus deviation occurred during the tibial LON. The medial proximal tibial angle increased from 86° (95% CI, 85°–86°) to 90° (95% CI, 89°–91°) (p < 0.001). The mechanical femorotibial angle changed from 2.2° varus (95% CI, 3°–1.4° varus) to 2.6° valgus (95% CI, 1.8°–3.4° valgus) (p < 0.001). Valgus deviation was evident in proximal and distal segments. In the multivariate regression model, use of a blocking screw was the only factor that was associated with decreased valgus deviation, and its effect size, although detectable, was small (−2.62; 95% CI, −4.65 to −0.59; p = 0.013).ConclusionsWe found that valgus deviation does occur during tibial lengthening using the LON technique, but that blocking screw placement may help to minimize the likelihood that severe valgus deviation will occur. Future prospective studies should be conducted to confirm this preliminary finding.Level of EvidenceLevel III, therapeutic study.


Clinical Orthopaedics and Related Research | 2015

Fixator-assisted Technique Enables Less Invasive Plate Osteosynthesis in Medial Opening-wedge High Tibial Osteotomy: A Novel Technique

Dong Hoon Lee; Keun Jung Ryu; Hae Hwa Kim; Sahyun Soung; Soowan Shin

Background Opening-wedge high tibial osteotomy is a well-established procedure in the management of medial osteoarthritis of the knee and correction of proximal tibia vara. Recently, surgical approaches using less invasive plate osteosynthesis have been used with the goal of minimizing complications from more extensive soft tissue exposures. However, to our knowledge, less invasive fixator-assisted plate osteosynthesis has not been tested in the setting of opening-wedge high tibial osteotomy.


Clinical Orthopaedics and Related Research | 2016

Is Botulinum Toxin Type A a Valuable Adjunct During Femoral Lengthening? A Randomized Trial.

Hoon Park; Soowan Shin; Han Sol Shin; Hyunwoo Kim; Dong Wook Kim; Dong Hoon Lee

BackgroundReduced joint ROM and distraction-induced pain are common complaints of patients who have undergone gradual femoral lengthening. Attempts to reduce the effects of lengthening on joint motion have included the use of botulinum toxin to reduce the muscle forces that restrict motion. The benefits of this approach during femoral lengthening, however, have not been conclusively established.Questions/purposesWe wished to evaluate the effects of botulinum toxin type A (BtX-A) injection in the anterior thigh muscles during femoral distraction osteogenesis on adjacent joint ROM and distraction-induced pain. We asked: (1) Does injection of BtX-A in the quadriceps muscles lead to improved knee and hip motion during femoral lengthening? (2) Does injection of BtX-A reduce pain during femoral lengthening?MethodsA single-center, double-blind, randomized placebo-controlled trial was conducted. Forty-four patients (88 femurs) undergoing bilateral femoral lengthening for familial short stature were included in the study. BtX-A (200 IU) was injected intraoperatively in the quadriceps muscles of one thigh. An equal volume of sterile normal saline was injected in the other thigh as a control. Selection of the limb receiving the toxin was randomized. Clinical evaluation included a VAS score for pain measurement, ROM evaluation of the hips and knees, and measurement of thigh circumference. Side-to-side differences were analyzed throughout the entire consolidation phase. No patients were lost to followup, leaving 44 patients (88 femurs). The mean followup was 26 months (range, 14–40 months). The distraction rate and final length of gain were similar between treated and control limbs. A priori power analysis suggested that 44 legs were required in each group to achieve statistical significance of 0.05 with 90% power to detect a 50% difference in treatment effect between treatment and control groups.ResultsThere were no differences in hip ROM, knee ROM, or maximal thigh circumference between the two lower extremities at any time during the study period. VAS scores were no different between the patients who received BtX-A and those who received saline.ConclusionsLocal injection of 200 IU BtX-A in the quadriceps muscles does not appear to reduce distraction-induced pain nor enhance ROM in the hip or knee during femoral lengthening. Additional studies are needed to evaluate the effect of larger doses or different injection methods. Based on our findings, we do not recommend routine use of botulinum injections during limb lengthening and believe any further use of this drug should only be in the context of a controlled trial.Level of EvidenceLevel II, therapeutic study.


Clinical Orthopaedics and Related Research | 2014

Reply to the Letter to the Editor Bone Marrow Aspirate Concentrate and Platelet-rich Plasma Enhanced Bone Healing in Distraction Osteogenesis of the Tibia

Dong Hoon Lee; Keun Jung Ryu; Jin Woo Kim; Kyung Chung Kang; Young Rak Choi

To the editor, In our investigation, we injected a combination of bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP) at the osteotomy site. Because of this approach, we could not determine which had a greater impact on bone healing, or whether they had any individual synergistic or antagonistic effects on the bone. As you noted, we do mention these limitations in our paper. We also agree with the need for additional studies, perhaps using research designs along the lines you suggest. The local application of the BMAC is gaining attention. In addition to its abundant mononuclear cells [6], it enables surgeons to perform both harvesting and transplanting at the same time during the surgery, preventing culture-related (in vitro) complications, such as decreased viability or contamination of the cells [6, 10]. The differentiation of osteoblasts from the BMC is well described and standardized [6]. The granules of platelet contain different kinds of growth factors, including platelet-derived growth factors, vascular endothelial growth factors, and transforming growth factor-beta [5]. These proteins set the stage for the tissue healing process, which includes cellular chemotaxis, proliferation, differentiation, and angiogenesis [3, 8]. The role of PRP in bone regeneration remains controversial, and while its mechanism is not yet fully understood, several experimental studies have identified a positive effect of PRP on bone healing [4, 5, 7]. Gandhi et al. [4] suggested that the PRP mediated early phase of bone repair process, up-regulated cellular proliferation, and improved mechanical strength of the healing bone. Kanno et al. [7] showed the PRP had a favorable effect on human osteoblast-like cells, and acted on enhancing bone regeneration. Gruber et al. [5] proved that the platelets stimulated the formation of osteoclast-like cells which can help bone growth and remodeling. Zhong et al. [11] reported that the PRP had similar ability with the BMAC on enhancing bone regeneration. However, there have been several other reports showing no effect of PRP on bone healing [1, 2, 9]. In light of these reports, I believe that BMAC may play a larger role than PRP. However, given the remaining gaps in our knowledge, I acknowledge that this matter will only be resolved by well-designed studies that have yet to be performed.


Clinical Orthopaedics and Related Research | 2014

Bone Marrow Aspirate Concentrate and Platelet-rich Plasma Enhanced Bone Healing in Distraction Osteogenesis of the Tibia

Dong Hoon Lee; Keun Jung Ryu; Jin Woo Kim; Kyung Chung Kang; Young Rak Choi


European Journal of Orthopaedic Surgery and Traumatology | 2014

The association between meniscal subluxation and cartilage degeneration.

Young Rak Choi; Jae Hwa Kim; Ju Hwan Chung; Dong Hoon Lee; Keun Jung Ryu; Doo Hoe Ha; Jinmyoung Dan; Sang Min Lee


Clinical Orthopaedics and Related Research | 2014

Botulinum Toxin A Does Not Decrease Calf Pain or Improve ROM During Limb Lengthening: A Randomized Trial

Dong Hoon Lee; Keun Jung Ryu; Dong Eun Shin; Hyunwoo Kim

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Soowan Shin

University of Southern California

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Ji Yeong Bae

Gyeongsang National University

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