The effect of heat treatment of the TI6AL4V specimen fabricated by selective laser melting method on the crystalline structure and chemical compositions / 대한치과재료학회지

In this study, the Ti6Al4V specimens were fabricated using selective laser melting (SLM) method (Ti6Al4V-AS group). These specimens were performed to heat treatment at 950℃ and 550℃ using vacuum electric furnace (Ti6Al4V-HT group). The mechanical properties, metallographic shape, crystalline structure, and chemical compositions of the alloy specimens before and after heat treatment were analyzed. The Ti6Al4V-AS group showed ultimate tensile strength (UTS) and low elongation values. Acicular crystal grains were observed in metallographic image and the α'-Ti phase was dominant. After heat treatment (Ti6Al4V-HT group), the UTS was lowered and the elongation was increased. In addition, a lamellar structure in which columnar crystal grains are arranged was observed, α+β-Ti phase was formed, and crystallinity increased. As a result of analyzing the chemical composition, the Ti6Al4V-AS specimen contained a higher carbon content than the Ti6Al4V-HT specimen. This high carbon content could be related to the formation of α'-phase, high strength and low elongation of the Ti6Al4V-AS specimen. Ti6Al4V-HT specimen showed that the overall carbon content was low, but the carbon content was locally high in the α-Ti phase region. Therefore, it is necessary to control effectively the incorporation of carbon gas in the production of Ti6Al4V specimens using SLM.

Patient-specific Three-dimensional Bone Model for the Diagnosis and Treatment of Orthopedic Diseases of the Hip: Opinions of Orthopedic Surgeons on New Medical Technology / 대한고관절학회지

Purpose@#To examine the perceptions and opinions of orthopedic surgeons on new medical technology for patient-specific three-dimensional (3D) bone models in the diagnosis and treatment of orthopedic diseases related to the hip joint. @*Materials and Methods@#A total of 75 doctors who were trained in orthopedic surgery or were current residents in the Republic of Korea were surveyed via questionnaires. Eight questions were included regarding the utility and current issues in the diagnosis and treatment of orthopedic disease using a customized 3D bone model made from s patient’s computed tomography (CT) image. In addition to the questionnaire, the simple plain radiography and 3D CT image of the patient and 3D printed models of two actual patients were presented for comparison. @*Results@#An average of 92.7% of the orthopedic surgeons answered “very much” or “yes” to questions regarding the effectiveness of diagnosis, treatment, education, and simulation of surgery using the patient-specific 3D bone model. To the question, “Do you think you must have medical insurance to provide better medical services by using a new patient-specific 3D bone model medical technology for simulated surgery?” 93.3% of orthopedic surgeons answered either “very much” or “yes”. @*Conclusion@#Patient-specific 3D bone models of new medical technology can provide breakthrough support in the diagnosis, treatment, and education of orthopedic diseases in the field of hip joints. Therefore, it seems that efforts should be made to change governmental policy for coverage of patient-specific 3D bone modeling.

Three-Dimensional Printing Technology in Orthopedic Surgery / 대한정형외과학회잡지

The use of 3-dimensional (3D) printing is becoming more common, and its use is increasing in the orthopedic surgery. Currently, there are four major methods of using 3D printing technology in orthopedic surgery. First, surgical planning simulation using 3D printing model; second, patient-specific surgical instruments; third, production of customized prosthesis using 3D printing technique; fourth, patient-specific prosthesis produced by 3D printing. The areas of orthopedic surgery where 3D printing technology can be used are shoulder joint, spine, hip and pelvis, knee joints, ankle joint, and tumors. Since the diseases and characteristics handled by each area are different, the method of using 3D printing technology is also slightly different in each area. However, using 3D printing technology in all areas can increase the efficiency of surgery, shorten the surgery time, and reduce radiation exposure intraoperatively. 3D printing technology can be of great help in treating patients with particularly complex and difficult orthopedic diseases or fractures. Therefore, the orthopedic surgeon should make the most of the benefits of the 3D printing technology so that patient can be treated effectively.

Sequential Bilateral Hip Fractures in Elderly Patients / 대한고관절학회지

Purpose@#To evaluate the incidence and presentation of osteoporotic sequential bilateral hip fractures (SBHF) in Center for Joint Disease, Chonnam National University Hwasun Hospital as there are limited studies with variable results reported in Korea. @*Materials and Methods@#Records of 507 patients aged >60 years old presenting with osteoporotic hip fractures between 2009 and 2015 were retrospectively reviewed to document the occurrence and presentation of sequential hip fractures; mean post-treatment follow-up was 48 months. Additionally, any correlations between sequential fractures and initial fracture and risk factors were assessed. Bone mineral density (BMD) was measured before and after sequential hip fracture for comparison. @*Results@#There were 246 femoral neck (Group A) and 261 intertrochanteric (Group B) fractures. The cumulative incidence of SBHF was 8.2% (42 patients total; 29 in Group A and 13 in Group B). Average interval of SBHF for Group A and Group B were 37.4 months and 29.9 months, respectively. There was significant correlation between the initial fracture type and sequential fractures, particularly the trochanteric and subgroup of those with neck fractures. Hypertension as a co-morbidity and female sex have been identified as risk factors for SBHF. No significant findings were noted regarding BMD and risk factors in both groups. @*Conclusion@#The clinical presentations of SBHF noted here concur with other worldwide studies and may guide efforts to develop relevant programs to prevent SBHF.

Three-dimensional-printing Technology in Hip and Pelvic Surgery: Current Landscape / 대한고관절학회지

The use of three-dimensional (3D) printing is becoming more common, including in the field of orthopaedic surgery. There are currently four primary clinical applications for 3D-printing in hip and pelvic surgeries: (i) 3D-printed anatomical models for planning and surgery simulation, (ii) patient-specific instruments (PSI), (iii) generation of prostheses with 3D-additive manufacturing, and (iv) custom 3D-printed prostheses. Simulation surgery using a 3D-printed bone model allows surgeons to develop better surgical approaches, test the feasibility of procedures and determine optimal location and size for a prosthesis. PSI will help inform accurate bone cuts and prosthesis placement during surgery. Using 3D-additive manufacturing, especially with a trabecular pattern, is possible to produce a prosthesis mechanically stable and biocompatible prosthesis capable of promoting osseointergration. Custom implants are useful in patients with massive acetabular bone loss or periacetabular malignant bone tumors as they may improve the fit between implants and patient-specific anatomy. 3D-printing technology can improve surgical efficiency, shorten operation times and reduce exposure to radiation. This technology also offers new potential for treating complex hip joint diseases. Orthopaedic surgeons should develop guidelines to outline the most effective uses of 3D-printing technology to maximize patient benefits.

Outcomes of Internal Fixation with Compression Hip Screws in Lateral Decubitus Position for Treatment of Femoral Intertrochanteric Fractures / 대한고관절학회지

PURPOSE: Internal fixation using compression hip screws (CHS) and traction tables placing patients in the supine position is a gold standard option for treating intertrochanteric fractures; however, at our institution, we approach this treatment with patients in a lateral decubitus position. Here, the results of 100 consecutive elderly (i.e., ≥45 years of age) patients who underwent internal fixation with CHS in lateral decubitus position are analyzed. MATERIALS AND METHODS: Between March 2009 and May 2011, 100 consecutive elderly patients who underwent internal fixation with CHS for femoral intertrochanteric fracture were retrospectively reviewed. Clinical outcomes (i.e., Koval score, Harris hip score [HHS]) and radiographic outcomes (i.e., bone union time, amount of sliding of lag screw, tip-apex distance [TAD]) were evaluated. RESULTS: Clinical assessments revealed that the average postoperative Koval score decreased from 1.4 to 2.6 (range, 0–5; P < 0.05); HHS was 85 (range, 72–90); and mean bone union time was 5.0 (range, 2.0–8.2) months. Radiographic assessments revealed that anteroposterior average TAD was 6.95 (range, 1.27–14.63) mm; lateral average TAD was 7.26 (range, 1.20–18.43) mm; total average TAD was 14.21 (range, 2.47–28.66) mm; average lag screw sliding was 4.63 (range, 0–44.81) mm; and average angulation was varus 0.72°(range, −7.6°−12.7°). There were no cases of screw tip migration or nonunion, however, there were four cases of excessive screw sliding and six cases of varus angulation at more than 5° CONCLUSION: CHS fixation in lateral decubitus position provides favorable clinical and radiological outcomes. This technique is advisable for regular CHS fixation of intertrochanteric fractures.

Subchondral Bone Restoration of Supra-acetabular Brown Tumor Secondary to Parathyroid Carcinoma: A Case Report / 대한고관절학회지

The causes of osteolytic lesions found in radiological examinations are not quite certain. Therefore, to determine the appropriate treatment method, various approaches and analyzes are required to find the real cause. Hyperparathyroidism is one of the diseases which forms osteolytic bone lesions so-called brown tumor. A 55-year-old woman who had painful osteolytic bone lesions in both hip joint areas was diagnosed as parathyroid carcinoma after serial work-up. She underwent parathyroidectomy and follow-up imaging showed a decrease in brown tumor size and bone consolidation in the subchondral bone destruction area. Proper evaluation of osteolytic bone lesions helps to avoid unnecessary operative treatments and the first choice for the treatment of osteolytic bone lesions caused by parathyroid carcinoma is parathyroidectomy.

Bone-forming peptide-2 derived from BMP-7 enhances osteoblast differentiation from multipotent bone marrow stromal cells and bone formation

Strategies for efficient osteogenic differentiation and bone formation from stem cells would have clinical applications in treating nonunion fracture healing. Many researchers have attempted to develop adjuvants as specific stimulators of bone formation for therapeutic use in patients with bone resorption. Therefore, development of specific stimulators of bone formation has therapeutic significance in the treatment of osteoporosis. To date, investigations of the mature forms of bone morphogenetic proteins (BMPs) have focused on regulation of bone generation. However, we previously identified new peptides from the immature precursor of BMP, and further analysis of these proteins should be performed. In this study, we identified a new peptide called bone-forming peptide-2 (BFP-2), which has stronger osteogenic differentiation-promoting activity than BMP-7. BFP-2 treatment of multipotent bone marrow stromal cells (BMSCs) induced expression of active alkaline phosphatase. In addition, BFP-2 enhanced CD44 and CD51 expression levels and increased Ca2+ content in BMSCs. Moreover, radiography at 8 weeks revealed that animals that had received transplants of BFP-2-treated BMSCs showed substantially increased bone formation compared with animals that had received BMSCs treated with BMP-7. Our findings indicate that BFP-2 may be useful in the development of adjuvant therapies for bone-related diseases.

Comparison of Outcomes of Total Hip Arthroplasty between Patients with Ankylosing Spondylitis and Avascular Necrosis of the Femoral Head

BACKGROUND: The objective of this study was to compare clinical and radiological outcomes of total hip arthroplasty (THA) between ankylosing spondylitis (AS) of the hip joint and avascular necrosis (AVN) of the femoral head. METHODS: Thirty patients (30 hips) underwent cementless THA for AS between 2003 and 2012. They were compared to 30 patients (30 hips) who underwent the same procedure for AVN of the femoral head. Each group was matched for age and gender, and both groups had similar preoperative demographic characteristics. All cases were followed for minimum 4 postoperative years. Clinical evaluation was based on operation time, intraoperative blood loss, quantity of postoperative drainage, Harris Hip Score (HHS), and range of motion (ROM). Radiological results were evaluated by acetabular cup anteversion and inclination, femoral stem orientation, pre- and postoperative leg length discrepancy, and postoperative complications. RESULTS: The operation time was significantly longer in the AS group (120.2 ± 26.2 min) than in the AVN group (79.5 ± 11.1 min). The volume of postoperative drainage was significantly greater in the AS group (764.5 ± 355.4 mL vs. 510.5 ± 195.6 mL). Preoperative HHS was lower in the AS group (55.6 ± 13.8 vs. 59.2 ± 2.8). Similarly, postoperative HHS was significantly lower in the AS group (92.8 ± 2.7 vs. 97.4 ± 2.6). The arc of ROM was improved from 146.5°± 13.2° preoperatively to 254.7°± 17.2° postoperatively in the AS group and from 182.6°± 15.5° to 260.4°± 13.7° in the AVN group. Implant position and postoperative leg length discrepancy were not different between the groups. However, three cases of heterotopic ossification was observed in the AS group, whereas only 1 case was found in the AVN group. One deep infection and one aseptic stem loosening were found in the AS group, whereas none was observed in the AVN group. CONCLUSIONS: Cementless THA showed satisfactory clinical and radiological results in both groups, despite the longer operation time, larger blood loss volume, and lower HHS score of the AS group. Our findings suggest that cementless THA is an effective and reliable treatment for both AS and AVN.

Bilateral Femoral Neck Stress Fracture Presented with Unilateral Symptoms in a Shipman Laborer: A Case Report / 대한고관절학회지

Femoral neck stress fracture occured commonly in athlete and military recruit populations, some of them are bilateral. Bilateral femoral neck stress fracture that associated with other occupation is very uncommon. We report a bilateral femoral neck stress fracture case that presented with unilateral symptoms in a male shipman laborer. The patient was successfully treated conservatively. Stress fracture sometimes occur associated with an unexpected specific occupation. Consideration of bilateral involvement is highly important in managing stress fracture.

Breakage of the Tail Portion of the Lag Screw during Removal of Proximal Femoral Zimmer Natural Nail: Report of Two Cases with Technical Notes / 대한고관절학회지

Proximal femoral cephalomedullary nailing is one of the treatments of choice for intertrochanteric fracture. Zimmer Natural Nail® (ZNN; Zimmer) is one of the alternatives. We report two cases of broken tail portion of the ZNN lag screw during the removal procedure. This may be the first reported cases in scientific literature with this pattern of failure. We report these cases to highlight one of the possible problems that could occur during removal of this implant which can possibly prolong the operation time significantly if the required device is not prepared.

Breakage of the Tail Portion of the Lag Screw during Removal of Proximal Femoral Zimmer Natural Nail: Report of Two Cases with Technical Notes / 대한고관절학회지

Proximal femoral cephalomedullary nailing is one of the treatments of choice for intertrochanteric fracture. Zimmer Natural Nail® (ZNN; Zimmer) is one of the alternatives. We report two cases of broken tail portion of the ZNN lag screw during the removal procedure. This may be the first reported cases in scientific literature with this pattern of failure. We report these cases to highlight one of the possible problems that could occur during removal of this implant which can possibly prolong the operation time significantly if the required device is not prepared.

Long-term Results of Modified Salter Innominate Osteotomy for Legg-Calvé-Perthes Disease

BACKGROUND: In a previous study, we reported clinical and radiographic results of our modified Salter innominate osteotomy technique in 16 hips affected by Legg-Calvé-Perthes disease (LCPD) with an average follow-up of 31.8 months. In this study, we present the long-term results of the osteotomy in LCPD patients followed until physeal closure. METHODS: Thirty hips of 29 patients were followed until skeletal maturation after modified Salter innominate osteotomy. The mean follow-up duration was 12.9 years (range, 9.1 to 16.0 years). Eleven hips (36.7%) were classified as Catterall group III and 19 (63.3%) as Catterall group VI. Stable interposition of a bone block was achieved using one biodegradable screw in nine hips and without any fixation device in 21 hips by simply changing the direction of osteotomy. The Harris Hip Score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and hip function were evaluated at the last follow-up. Radiological outcomes were evaluated using Wiberg's center-edge angle, the Mose method, and Stulberg classification, and osteoarthritic changes were evaluated using the Tonnis classification. RESULTS: Mean HHS and WOMAC score were 80.2 points and 54 points, respectively, preoperatively and these were improved to 96.2 points and 28 points, respectively, at the last follow-up. Clinical results, according to Robinson's criteria, were good in 18, fair in seven, and poor in five hips. Radiological results assessed using the Mose method were good in 18, fair in six, and poor in six hips, and according to the Stulberg classification, nine hips were class I, nine were class II, eight were class III, and four were class IV. The mean center-edge angle improved from 19.7° preoperatively to 29.6° at the final follow-up. According the Tonnis classification, three hips were grade 2, five were grade 1, and 22 were grade 0. Of the three grade 2 hips, two underwent Chiari osteotomy 12.1 and 8.8 years postoperatively, and the other underwent total hip arthroplasty 12.9 years postoperatively. CONCLUSIONS: The modified Salter innominate osteotomy produced relatively satisfactory long-term clinical and radiological results.

Bilateral Femoral Neck Stress Fracture in Child: A Case Report / 대한고관절학회지

A femoral neck stress fracture in child is rare, particularly in bilateral case. It is easy to miss initially or may be misdiagnosed. The authors experienced a case of bilateral femoral neck stress fracture in a 10-year-old boy with bilateral hip. The patient was successfully healed by conservative treatment. We report this rare case with a review of the literature. A femoral neck stress fracture should be included in the differential diagnosis in children who present with sustained hip or groin pain.

Results of Total Hip Arthroplasty after Core Decompression with Tantalum Rod for Osteonecrosis of the Femoral Head

BACKGROUND: Early stage osteonecrosis of the femoral head (ONFH) has many treatment options including core decompression with implantation of a tantalum rod. The purpose of this study was to evaluate clinical and radiological outcomes and potential complications during conversion total hip arthroplasty (THA) in such patients. METHODS: Six male patients (8 hips) underwent THA subsequent to removing a tantalum rod (group I) from April 2010 to November 2011. We retrospectively reviewed the medical records of these patients. We enrolled 12 age- and sex-matched patients (16 hips) during the same period, who had undergone primary THA without a previous operation as the control group (group II). All patients were followed for at least 3 years. We checked the Harris hip score (HHS), operative time, and volume of blood loss. Radiological results, including inclination, anteversion of the acetabular cup, presence of periprosthetic osteolysis, and subsidence of femoral stem were checked at the last follow-up. RESULTS: The mean preoperative HHS values were 56.5 (range, 50 to 62) and 59.1 (range, 42 to 70) in groups I and II, respectively. The HHS improved to 96.0 (range, 93 to 100) and 97.6 (range, 93 to 100), respectively, at the 3-year follow-up (p = 0.172). Mean operation time was 98.8 minutes (range, 70 to 120 minutes) in group I and 77.5 minutes (range, 60 to 115 minutes) in group II (p = 0.006). Total blood loss volumes were 1,193.8 mL (range, 960 to 1,360 mL) and 944.1 mL (range, 640 to 1,280 mL) in groups I and II, respectively (p = 0.004). No significant differences in inclination or anteversion of acetabular cup and no evidence of osteolysis or subsidence of the femoral stem were reported in either group in radiological follow-up results. However, one case of squeaking occurred in group I during the follow-up. CONCLUSIONS: The two groups showed no clinical or radiological differences except extended operative time and increased blood loss. However, the incidence of squeaking (1 of 8 hips) was higher, as compared to the control group or previously reported values.

The Clinical and Radiological Results of Vancouver Type B1 and C Periprosthetic Fractures

PURPOSE: The purpose of this study is to evaluate the clinical and radiologic results of plate fixation in the Vancouver B1 and C periprosthetic femoral fracture (PFF). MATERIALS AND METHODS: Twenty patients who had sustained a Vancouver type B1 and C periprosthetic fracture after hip arthroplasty (years 2002-2012) were identified. The mean age was 66.0 years (range, 43-85 years) and the mean follow-up duration of the group was 38 months (range, 12-102 months). The dynamic compression plate (DCP) group included 12 patients and the locking compression plate (LCP) group included eight patients. Harris hip score (HHS) and walking ability, knee joint range of motion (ROM) were compared before injury and last follow-up. Fracture union rate and period were compared. RESULTS: The mean HHS score was 90.7 (64-96). There was no statistical difference between the two groups. At the last follow-up, knee joint ROM was 103.3degrees (105degrees-140degrees) in the DCP group and 118.4degrees (110degrees-140degrees) in the LCP group, showing good results in the LCP group (p=0.043). No significant difference in the fracture union rate and union periods was observed between the two groups. CONCLUSION: A better result for the postoperative knee flexion exercise capacity was observed in the LCP group. Use of LCP plate fixation is a good option in management of Vancouver classification B1 and C PFF.

The Result of Total Hip Arthroplasty after Failure of Multiple Screw Fixation for Femoral Neck Fracture / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to analyze the result of secondary total hip arthroplasty (THA) after primary internal fixation failure in femoral neck fracture patients and compare the results with primary THA for femoral neck fracture. MATERIALS AND METHODS: Among the femoral neck fracture patients, we analyzed clininal and radiologic results of those who underwent secondary THA after internal fixation failure and those who underwent THA as early treatment. Cases with patients over age 40 years and with at least two year of follow-up period were used for analysis. Periopertive conditions of patients were evaluated by using surgery time, bleeding amounts and period to start gait using walker or crutch after surgery. Clinical results were assessed by using Harris hip score and Western Ontario and McMaster Universities Osteoarthritis Index, and radiologic results were derived by observing follow-up simpe X-ray. RESULTS: The group of secondary THA had longer surgery time, more bleeding amount and longer period to start gait. But between the two groups, there was no difference of clinical and radiologic result at final follwing up. Both of two group had excellent clinical and radiological results. CONCLUSION: THA after internal fixation showed excellent clinical and radiologic results that was comparable to compare with primary THA.

Postoperative Complications and Cost-effectiveness of Simultaneous and Staged Bilateral Total Hip Arthroplasty Using a Modified Minimally Invasive Two-incision Technique / 대한고관절학회지

PURPOSE: To compare the postoperative complications and cost-effectiveness of simultaneous and staged bilateral total hip arthroplasty (THA), using a minimally invasive two-incision technique. MATERIALS AND METHODS: All 206 patients who underwent simultaneous or staged bilateral THA using a modified, minimally invasive two-incision between January 2004 and November 2009 were registered and divided into a simultaneous bilateral THA group (group A, 147 patients) and staged bilateral THA group (group B: 59 patients). Staged THA was performed on group B with interval of at least 2 months between the initial and second surgery. Clinical evaluations, amount of blood loss, need for transfusion, complications and costeffectiveness were compared. RESULTS: Perioperative morbidity rates were similar in the two groups (P=0.546) and overall complications were not significant between the groups. Average length of hospital stay was significantly shorter in group A than in group B (average 14.6 days vs. 25.3 days; P<0.001). Total medical cost was significantly higher in group B than in group A (average 9,236 US dollars vs. 11,163 US dollars). Patients in group A required more blood transfusions than those in group B (3.02 vs. 1.90 units; P=0.003), although blood loss in the two groups were similar (892 vs. 917 ml P=0.613). CONCLUSION: Comparison of intra- and postoperative complications support the conclusion that simultaneous bilateral THA compares favorably with staged THA in terms of outcomes, complications and cost-effectiveness.

Posttraumatic Osteonecrosis of the Femoral Head after Nine Years of Posterior Femoral Head Fracture Dislocation / 대한정형외과학회잡지

Posttraumatic osteonecrosis of the femoral head (ONFH) is the most serious complication after fracture dislocation of the femoral head. The rate of this complication was reported to range from 1.7% to 40%. Although the development of posttraumatic osteonecrosis normally occurs within 2 years of injury, there are some reports of the late development ONFH. The authors encountered a case of posttraumatic ONFH that developed after 9 years of a Pipkin type I fracture dislocation. The patient was treated by modified transtrochanteric rotational osteotomy. We report this rare case with a review of the relevant literatures.

Retraction: Comparison of Accuracy of Navigation between Infrared Optical and Electromagnetic Systems / 대한정형외과학회잡지

This article has been retracted.