• The Journal of the Korean bone and joint tumor society
• /
• v.8 no.1
• /
• pp.1-11
• /
• 2002

Purpose : We evaluated the radiological and functional results of prosthetic reconstruction for locally aggressive benign and malignant tumor in the lower extremity. Materials and Methods : Eighty eight patients were followed up for an average 76 months(22~174). We examined the survival rate of prosthesis, and evaluated the final result by MSTS functional score and ISOLS radiological implants evaluation system. They were statistically analyzed according to the age(<20 year vs. ${\geq}$20 year), fixation methods, amount of bony resection, chemotherapy, local recurrence, and presence of metastasis. Results : The 5 year prosthetic survival rates were 100% in the proximal femur, 83.3% in the distal femur, 81.9% in the proximal tibia. Mean total functional scores were 73.3%, 72%, 68.7%, respectively. In distal femur, the non-chemotherapeutic group was superior in the prosthetic survival rate. Recurrence or metastasis affected the functions in the distal femur and proximal tibia. In the radiological evaluation of the distal femur, older patients over 20 years of age and with cement fixation were superior in bone remodeling(p<0.05). Postoperative infection and radiological loosening were the main causes of the prosthetic failure. Conclusion : The prosthetic reconstruction in the lower extremity led to good clinical and radiological results. Amount of bony resection, chemotherapy, recurrence and metastasis seemed to influence the prosthetic survival, and long-term follow-up will be necessary to investigate more significant prognostic factors.

• Clinics in Shoulder and Elbow
• /
• v.15 no.1
• /
• pp.37-42
• /
• 2012

Purpose: To consider the proper management of proximal humerus fracture on gunshot wounds. Materials and Methods: A 28-year-old male patient, who sustained a gunshot injury on the left arm 5 days ago, was admitted through the emergency department. Although he underwent an emergency surgery (bullet fragment removal and debridement), there remained bullet fragments around the proximal humerus fracture site. The wound seemed to be infected and a partial dehiscence occurred. No neurologic deficit was noted. Immediate exploration and debridement were performed, and an external fixator was applied to restore the anatomical alignment and manage the wounds. Intravenous antibiotics were administered. On the 9th postoperative day, wound debridement was done again, and cement beads mixed with antibiotics were inserted. After two weeks, the external fixator was removed, and the pin sites were closed after debridement. One week later, the open reduction and internal fixation with locking compression plate and screws were done. Result: At 3 months after the internal fixation, the bone union was obtained with satisfactory alignment of the humerus. Conclusion: The severity of the soft tissue injury influences the fracture management plan. Further, the risk on lead toxicity should be considered.

• Clinics in Shoulder and Elbow
• /
• v.16 no.2
• /
• pp.170-177
• /
• 2013

Total elbow arthroplasty is still in its infancy compared with other arthroplasties, such as knee or hip arthroplasties. Implant design has been evolving with clinical experiences; however, there are only limited data on the long-term clinical outcome of elbow arthroplasty in the literature. The design of total elbow prostheses can be divided into three categories: linked (constrained or semi-constrained), unlinked (unconstrained), and convertible types. The choice between an unlinked (unconstrained) implant and a linked (semi-constrained) implant depends on joint stability and adequacy of the bone stock. Linked elbow arthroplasty has provided high patient satisfaction, and pain relief thanks to proper patient selection, advancement of implant design, improvement in cement techniques, meticulous surgical technique, and appropriate postoperative rehabilitation. Concerns remain about the use of this implant in young or high-demand patients. This article focuses on the linked (semi-constrained) prostheses, which provides an overview of the current state of linked total elbow arthroplasty.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.4
• /
• pp.498-505
• /
• 2020

Aggregate occupies about 70-85% of the concrete volume and is an important factor in reducing the drying shrinkage of concrete. However, when constructing high-rise buildings, it acts as a problem due to the high load of natural aggregates. If the load becomes large during the construction of a high-rise building, creep may occur and the ground may be eroded. Material costs increase and there are financial problems. In order to reduce the load on concrete, we are working to reduce the weight of aggregates. However, artificial lightweight aggregates affect the interface between the aggregate and the paste due to its higher absorption rate and lower adhesion strength than natural aggregates, affecting the overall strength of concrete. Therefore, in this study, in order to grasp the interface between natural aggregate and lightweight aggregate by type, we adopted a method of measuring electrical resistance using an EIS measuring device, which is a non-destructive test, and lightweight bone. The change in the state of the interface was tested on the outside of the material through a blast furnace slag coating. As a result of the experiment, it was confirmed that the electric resistance was about 90% lower than that in the air-dried state through the electrolyte immersion, and the electric resistance differs depending on the type of aggregate and the presence or absence of coating. As a result of the experiment, the difference in compressive strength depending on the type of aggregate and the presence or absence of coating was shown, and the difference in impedance value and phase angle for each type of lightweight aggregate was shown.

• The Journal of the Korean bone and joint tumor society
• /
• v.10 no.2
• /
• pp.71-78
• /
• 2004

Purpose: The purpose of this study is to investigate the characteristic of recurred giant cell tumor after bony curettage and cementation, and to review a way to prevent the recurrence. Materials and Methods : Thirty seven cases were analyzed, which were pathologically diagnosed giant cell tumor after diagnostic biopsy or surgical excision, followed by curative curettage, burring and cementation. Location, character, and time interval to recurrence were reviewed. Results: Thirteen out of thirty seven analyzed cases(35%) showed recurrence after primary curettage and cementation. The mean interval to recurrence was sixteen months(5 months to 43 months). Most of recurrence happened within the first two years except two cases. Among the recurred cases, eleven showed recurrence in the vicinity of window area. Two cases recurred in the depth of bone marrow, where cementation was made. The advantage of curettage and cementation is the immediate stability of the operation site, early rehabilitation, and early detection of recurrence. Furthermore, cementation is beneficial in that the cement-producing heat can eradicate the residual tumor burden. In this study, 85% of cases with insufficient curettage (for example, in cases where too small surgical window was made, or where there were anatomical difficulty in approaching the target tumor burden) showed recurrence. Conclusion: Bony curettage, burring and cementation is widely used as the primary curative modality for giant cell tumor. A few other modalities such as chemical cautery using phenol and $H_2O_2$; cryotherapy; and anhydroalcohol have also been introduced, but the benefit of these are still questionable. For some cases that relatively small surgical window was made due to anatomically complicated structures (such as ligament insertion or origin site) over the target tumor burden, unsatisfactory curettage and burring was made. This study showed high chance of recurrence after unsatisfactory curettage, and 85% of recurrence developed in the vicinity of the small window area. Most of the recurrence occurred within the first two years. It is concluded that sufficient window opening, extensive curettage and eradicative burring are key factors to prevent recurrence. Also, it should be reminded that careful and close observation should be made for at least the first two years after initial treatment for early detection of recurrence.

• Journal of the Korean Orthopaedic Association
• /
• v.54 no.4
• /
• pp.327-335
• /
• 2019

Purpose: To investigate the radiological efficacy of polymethylmethacrylate (PMMA) augmentation of pedicle screw operation in osteoporotic vertebral compression fractures (OVCF) patients. Materials and Methods: Twenty OVCF patients, who underwent only posterior fusion using pedicle screws with PMMA augmentation, were included in the study. The mean follow-up period was 15.6 months. The demographic data, bone mineral density (BMD), fusion segments, number of pedicle screws, and amount of PMMA were reviewed as medical records. To analyze the radiological outcomes, the radiologic parameters were measured as the time serial follow-up (preoperation, immediately postoperation, postoperation 6 weeks, 3, 6 months, and 1 year follow-up). Results: A total of 20 patients were examined (16 females [80.0%]; mean age, 69.1±8.9 years). The average BMD was -2.5±0.9 g/cm². The average cement volume per vertebral body was 6.3 ml. The mean preoperative Cobb angle of focal kyphosis was 32.7°±7.0° and was improved significantly to 8.7°±6.9° postoperatively (p<0.001), with maintenance of the correction at the serial follow-up, postoperatively. The Cobb angle of instrumented kyphosis, wedge angle, and sagittal index showed similar patterns. In addition, the anterior part of fractured vertebral body height averaged 11.0±5.0 mm and was improved to 18.5±5.7 mm postoperatively (p=0.006), with maintenance of the improvement at the 3-month, 6-month, and 1-year follow-up. Conclusion: The reinforcement of pedicle screws using PMMA augmentation may be a feasible surgical technique for OVCF. Moreover, it appears to be appropriate for improving the focal thoracolumbar/lumbar kyphosis and is maintained well after surgery.

• The Journal of Korean Academy of Prosthodontics
• /
• v.54 no.3
• /
• pp.239-245
• /
• 2016

Purpose: The purpose of this study was to identify clinical complications in removable partial denture (RPD) with implant-supported surveyed prostheses, and to analyze the factors associated with the complications such as location of the implant, splinting adjacent prostheses, the type of retentive clasps, Kennedy classification, and opposing dentition. Materials and Methods: A retrospective clinical study was carried out for 11 patients (7 male, 4 female), mean age of 67.5, who received RPD with Implant-supported surveyed prostheses between 2000 and 2016. The mechanical complications of 11 RPDs and 37 supporting implant prostheses and the state of natural teeth and peripheral soft tissue were examined. Then the factors associated with the complications were analyzed. Results: The average of 3.4 implant-supported prostheses were used for each RPD. Complications found during the follow-up period of an average of 42.1 months were in order of dislodgement of temporary cement-retained prostheses, opposing tooth fracture/mobility, screw fracture/loosening, clasp loosening, veneer porcelain fracture, marginal bone resorption and mobility of implant, artificial tooth fracture. Complications occurred more frequently in anterior region compared to posterior region, non-splinted prostheses compared to splinted prostheses, surveyed prostheses applied by wrought wire clasp compared to other clasps, and natural dentition compared to other removable prostheses as opposing dentition. There were no significant differences in complications according to the Kennedy classification. Conclusion: All implant-assisted RPD functioned successfully throughout the follow-up. However, further clinical studies are necessary because the clinical evidences are still not enough to guarantee the satisfactory prognosis of implant-assisted RPD for long-term result.

• The Journal of Korean Academy of Prosthodontics
• /
• v.32 no.1
• /
• pp.120-147
• /
• 1994

This study was performed for the purpose of evaluating the stress distribution around threaded type implants, cylindrical type implants and teeth connected with rigid or non-rigid connector. The stress distribution around the surrounding bone was analyzed by three-dimensional photoelastic method. Twelve mandibular photoelastic epoxy resin models and a circular polariscope were used to record the isochromatic fringes. After the stress distribution around the implant and tooth was observed, the results were as follows ; 1. In threaded type implants, stress concentrated patterns were observed at the neck either vertical or 25 degree lateral force. 2. The stress concentrated patterns were observed at the tooth apical portion and neck portions of the implant and tooth when a threaded implant was connected with the tooth by either a rigid or non-rigid connector. More force was generated at the tooth neck portion by a rigid connector and more force at the implant neck portion by a non-rigid connector. 3. The stress concentrated patterns were observed at the apical portion of the implant and tooth when a cylindrical type ,implant was connected with the tooth either by a rigid or non-rigid connector. More force was generated at the tooth apical portion by a rigid connector and more force at the neck portion of the tooth and implant by a non-rigid connector. 4. The stress around the tooth was more equally distributed in a threaded type implant than in a cylindrical implant when the tooth was connected with either a rigid or non-rigid connector. 5. The stress around a threaded type implant was progressively more equally distributed in the following order : 1) when used a single implant, 2) a non-rigid connection with the implant and tooth, 3) a rigid connection with the implant and tooth, 4) a rigid connection with two implant fixtures.