Byung-Ho Yoon

Chitosan/nanohydroxyapatite composite membranes via dynamic filtration for guided bone regeneration.

Chitosan/hydroxyapatite (HA) composite membranes were prepared by the coprecipitation method and a subsequent dynamic filtration and freeze-drying process. The influences of the HA content of the membranes on their phase and morphology, mechanical properties, and bioactivity were investigated. FTIR analysis revealed that chitosan and HA had good miscibility over a wide range of compositions. Needle-like HA nanocrystals with low crystallinity were uniformly embedded in the chitosan matrix. As the HA content was increased, the tensile strength of the membranes exhibited a steady decrease, while the elastic modulus increased by a factor of 2 when 20% HA was added. The results of the in vitro cell culture showed that the highest alkaline phosphatase level was achieved when 30% HA was contained in the composites.

Epidemiology of osteoporosis and osteoporotic fractures in South Korea.

Several epidemiologic studies suggested that osteoporosis and osteoporotic fractures are not uncommon in South Korea. However, these previous cohort studies had limitations that may have influenced their results and the generalizability of the study conclusions, including small sample sizes, inclusion of only women, enrollment of participants from specific areas, and nonrandom selection of participants. Recently, epidemiologic studies using a nationwide claim register have been performed to overcome these limitations through collaboration between the Korean Society of Bone and Mineral Research and Health Insurance Review Assessments. Our review of the Korean Nationwide-database Osteoporosis Study could be helpful to obtain accurate incidence and prevalence estimations of osteoporosis and osteoporosis-related fractures in Korea.

National Trends of Hip Arthroscopy in Korea

Hip arthroscopy has been reported to be useful and promising for the treatment of hip pathologies. However, it is not known whether the utilization of hip arthroscopy has increased in Korea. The purpose of this study was to evaluate national trends regarding the utilization of hip arthroscopy in Korea. We retrospectively reviewed nationwide data obtained from the Health Insurance Review and Assessment Service (HIRA). All new admissions for hip arthroscopy are recorded nationwide by HIRA using the ICD-10 code and the code for arthroscopic devices. Using archived data, we determined the trends in utilization of hip arthroscopy between 2007 and 2010. The number of hip arthroscopies increased more than twofold over the study period, from 596 to 1,262. A third of cases were performed in hospitals. Furthermore, a bimodal distribution was observed for men (20 to 24 yr and 45 to 49 yr) and an unimodal distribution for women (50 to 54 yr). Our results show an increasing trends in the utilization of hip arthroscopy from 2007 to 2010, which is in-line with recent findings of increased utilization with the rest of the world. Graphical Abstract

Learning Curve of Acetabular Cup Positioning in Total Hip Arthroplasty Using a Cumulative Summation Test for Learning Curve (LC-CUSUM)

Despite advances in surgical techniques and instrumentation, optimal cup positioning in total hip arthroplasty (THA) is challenging with a limited accuracy. We evaluated whether a learning curve exists for the optimal cup positioning, using the LC-CUSUM test (Learning curve cumulative summation test). We evaluated the first 100 consecutive THA performed by two surgeons, who had a year of fellowship training in the same teaching hospital. A learning curve of cup positioning was plotted in each series using the LC-CUSUM score. There was no significant difference of numbers of outlier between two surgeons (P = 0.079). Both surgeons completed the learning curve of optimal cup positioning before 50 procedures, and maintained competence. A substantial learning period is necessary in the optimal positioning of an acetabular cup.

Epidemiology of proximal femoral fractures in South Korea

SummaryWe determined the incidence of femoral neck, intertrochanteric, and subtrochanteric fractures and compared the demographic characteristics of each fracture group in the Korean population.PurposeAll proximal femur fractures (femoral neck, intertrochanteric, and subtrochanteric fracture) have been considered to have similar demographics and to be related with osteoporosis. However, there has been lack of comparison with demographics of each fracture. Our purposes were to determine the incidences of femoral neck, intertrochanteric, and subtrochanteric fracture and to compare the demographic characteristics of each fracture group in the Korean population.MethodsWe assessed the demographic characteristics of proximal femoral fractures (femoral neck, intertrochanteric, and subtrochanteric) in the entire Korean population in 2010 by accessing nationwide data from the Health Insurance Review Assessment Service (HIRA). After proper identification using International Classification of Diseases, 10th revision (ICD-10) codes, we calculated absolute number and age- and gender-specific incidence rates for each proximal femoral fracture group.ResultsThe incidences of femoral neck, intertrochanteric, and subtrochanteric fractures were 29.3, 26.8, and 2.0 per 100,000 persons, respectively. In a population of over 60-year-old individuals, the incidences of hip fracture (femoral neck and intertrochanteric fracture) in men and women were 260.0 and 527.0 per 100,000 persons, and the incidences of subtrochanteric fracture in men and women were 7.2 and 13.2 per 100,000 persons. The incidences of subtrochanteric fractures insensibly increased, while the incidences of femoral neck and intertrochanteric fractures exponentially increased with aging.ConclusionsThe demographic characteristic patterns of the patients with subtrochanteric fractures were not similar to those of patients with femoral neck and intertrochanteric fractures, which are typically categorized as osteoporosis-related fractures.

Total Hip Arthroplasty Performed in Patients with Residual Poliomyelitis: Does it Work?

BackgroundPatients with residual poliomyelitis can have advanced degenerative arthritis of the hip in the paralytic limb or the nonparalytic contralateral limb. Although THA is a treatment option for some of these patients, there are few studies regarding THA in this patient population.Questions/purposesWe therefore reviewed a group of patients with residual poliomyelitis who underwent cementless THA on either their paralytic limb or nonparalytic limb to assess (1) Harris hip scores, (2) radiographic results, including implant loosening, (3) complications, including dislocation, and (4) limb length discrepancy after recovery from surgery.MethodsFrom January 2000 to December 2009, 10 patients with residual poliomyelitis (10 hips, four paralytic limbs and six nonparalytic contralateral limbs) underwent THA using cementless prostheses. Harris hip scores, complications, and leg length discrepancy were determined by chart review, and confirmed by questionnaire and examination; radiographs were reviewed by two observers for this study. Followup was available for all 10 patients at a minimum of 3 years (median, 7 years; range, 3.4–13 years). Surgery was done at the same side of the paralytic limb in four hips and contralateral to the paralytic limb in six.ResultsAll patients had pain relief and improvement in function; the Harris hip score improved from mean of 68 preoperatively to 92 at last followup (p = 0.043). However, only three patients had complete pain relief. One hip dislocated, which was treated successfully with closed reduction and a hip spica cast for 2 months. There was no loosening or osteolysis in this series. Leg length discrepancy improved after the index operation, but only in the THAs performed in the paralytic limbs.ConclusionsCementless THA may be suitable for painful hips in adult patients with residual poliomyelitis. Nonetheless, these patients should be informed of the possibility of mild residual pain and persistent leg length discrepancy, particularly patients whose THA is performed on the limb that was not affected by polio (ie, the nonparalytic contralateral limb).Level of EvidenceLevel IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

National Trends of Surgical Treatment for Intertrochanteric Fractures in Korea

Intramedullary nailing has been reported to have better outcome compared with traditional plate fixation in surgical treatment of intertrochanteric fractures. We evaluated the trends of surgical treatment of intertrochanteric fracture in Korea. Data of patients with intertrochanteric fractures, who were operated between the years of 2006 and 2011, was obtained from the Health Insurance Review and Assessment Service. The ratio of intramedullary nailing increased from 27.9% in 2006 to 64.3% in 2011 (P < 0.001), while the ratio of plate fixation decreased. During recent 5 yr, the utilization of intramedullary nailing doubled in clinical practice of intertrochanteric fractures in Korea.

The Efficacy of Bisphosphonates for Prevention of Osteoporotic Fracture: An Update Meta-analysis

Background The efficacy of bisphosphonates for osteoporotic fracture has been consistently reported in recent randomized controlled trials (RCTs) enrolling hundreds of patients. The objective of this study was to update knowledge on the efficacy of available bisphosphonates in the prevention of vertebral and non-vertebral fractures. Methods An approach “using systematic reviews” on PubMed and Cochrane Library was taken. Twenty-four RCTs investigating the effects of bisphosphonates for the prevention of osteoporotic fracture were included in final analysis. A pairwise meta-analysis was conducted with a random effects model. Subgroup analysis was performed according to the type of bisphosphonate. Results The use of bisphosphonate decrease the risk of overall osteoporotic fracture (odds ratio [OR] 0.62; P<0.001), vertebral fracture (OR 0.55; P<0.001) and non-vertebral fracture (OR 0.73; P<0.001). Subgroup analysis indicated that zoledronic acid showed the lowest risk reduction (OR 0.61; P<0.001) for overall osteoporotic fractures but no significance was observed for etidronate (OR 0.34; P=0.127). Conclusions This update meta-analysis re-confirmed that bisphosphonate use can effectively reduce the risk of osteoporotic fracture. However, there is a lack of evidence regarding etidronate for the prevention of osteoporotic fracture.

Sexual Activity after Total Hip Replacement in Korean Patients: How They Do, What They Want, and How to Improve

Background Concerns of patients on sexual activity after total hip arthroplasty have not been well studied in Asian patients. This study aimed to determine the following: (1) what are the concerns of patients related to sexual activity after total hip arthroplasty? (2) what are the changes in sexual activity after total hip replacement in Korean patients? Methods Details of sexual activity and concerns were obtained using a questionnaire designed specifically for the study. The questionnaire was administered to 64 patients in a face-to-face interview at an outpatient clinic. Results Preoperatively, 53.1% of patients experienced difficulties, primarily due to hip pathology and limitations of motion. The median time to the resumption of sexual activity was 3 months postoperatively, and most patients had no increase in the frequency of sexual activity after the total hip replacement. In 39.1% of patients were seen having difficulties with leg positioning following total hip replacement, and they were likely to change coital positions. The most common concern regarding sexual activity of patients was the fear of dislocation. Furthermore, patients with a higher stress level had lower satisfaction rates. Most patients were unable to obtain information on sexual activity following the total hip arthroplasty, and they did not consult with a physician due to the private nature of the topic. Conclusions Dislocation was the most common concern of patients during sexual activity following a total hip arthroplasty, and a higher stress level was found to be associated with a lower satisfaction rate. Because most patients were unprepared to consult a physician, the provision of appropriate information before a consultation might be beneficial.

Postoperative Deep Infection After Cemented Versus Cementless Total Hip Arthroplasty: A Meta-Analysis

Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty (THA). The objective of this meta-analysis was to compare the PJI rate between cemented and cementless THAs. Eight clinical studies (2 randomized controlled trials and 6 observational studies) were available for the analysis. Meta-analysis (with a fixed-effects model) and subgroup analysis were performed by research design and meta-regression was performed by continuous moderator. The overall incidence of PJI was 0.4% (357/84,200). The incidence was 0.5% (310/67,531) in cemented group, and 0.3% (47/16,669) in cementless group (P=0.008). The meta-analysis revealed that the use of cement in THA was associated with an increased risk of PJI (odds ratio 1.53; 95% confidence interval 1.120 to 2.100; P=0.008).