Dae Gyu Kwon

Arthroplasty versus arthrodesis for end-stage ankle arthritis: decision analysis using Markov model

BackgroundTotal ankle arthroplasty and arthrodesis are the two mainstreams of treatment for end-stage ankle arthritis. This study was performed to determine which is a better choice for ankle arthritis, using a decision analysis and Markov model to reflect the repetitive nature of revision arthroplasty.MethodsBased on current published evidence, a decision tree was constructed to compare the clinical outcomes of total ankle arthroplasty and arthrodesis, which contained the possible clinical events and the probabilities. Total ankle arthroplasty was subject to revision arthroplasty, and a Markov model was adopted for this branch to reflect this repetitive trait of the procedure. Arthrodesis could cause adjacent arthritis, and a conventional decision analysis model was adopted for this branch. Quality well-being index score was used for clinical outcome assessment, which was the utility in the decision tree. Sensitivity analysis was performed to test the stability of the decision tree and the threshold values.ResultsThe model favoured total ankle arthroplasty over arthrodesis in terms of quality well-being index score. Sensitivity analysis showed that the model was considerably stable, unaffected by the changes in probabilities of failure after total ankle arthroplasty and adjacent arthritis after arthrodesis.ConclusionsBased on current evidence, total ankle arthroplasty was found to be a better treatment than arthrodesis for ankle arthritis. Future development in the implant materials, improved understanding of ankle biomechanics, and surgical techniques will further enhance the clinical outcome of total ankle arthroplasty.

Prophylactic femoral varization osteotomy for contralateral stable hips in non‐ambulant individuals with cerebral palsy undergoing hip surgery: decision analysis

Aim  This study was undertaken to determine the need for concurrent prophylactic femoral varization osteotomy (FVO) of contralateral stable hips at the time of hip reconstructive surgery on unstable hips in non‐ambulant individuals with cerebral palsy (Gross Motor Function Classification System levels IV and V).

Clinical results of auto-iliac cancellous bone grafts combined with implantation of autologous bone marrow cells for osteonecrosis of the femoral head: a minimum 5-year follow-up.

Purpose There are no reports about bone graft and cell therapy for the osteonecrosis of femoral head (ONFH). We prospectively evaluated the clinical results of auto-iliac cancellous bone grafts combined with implantation of autologous bone marrow cells for ONFH. Materials and Methods Sixty-one hips in 52 patients with ONFH treated with bone graft and cell therapy were enrolled, and the average follow-up of the patients was 68 (60-88) months. Necrotic lesions were classified according to their size by the Steinberg method and location of necrosis. Results At the last follow-up, the percentage of excellent or good results was 80% (12/15 hips) in the small lesion group, 65% (17/26 hips) in the medium size group, and 28% (6/20 hips) in the large size group. The procedures were a clinical success in 4 of 5 hips (80%) of stage I, 23 of 35 hips (65.7%) of stage II, 7 of 18 hips (38.9%) of stage III, and 1 of 3 hips (33.3%) of stage IV grade, according to the Association Research Circulation Osseous grading system. Among the 20 cases with large sized necrotic lesions, 17 cases were laterally located and this group showed the worst outcomes, with 13 hips (76.5%) having bad or failed clinical results. Conclusion The results of the present study suggested that patients who have a large sized lesion or medium sized laterally located lesion would not be good candidates for the head preserving procedure. However, for medium sized lesions, this procedure generated clinical results comparable to those of other head preserving procedures.

Incidence patterns of pediatric and adolescent orthopaedic fractures according to age groups and seasons in South Korea: a population-based study.

Background Fractures which need urgent or emergency treatment are common in children and adolescents. This study investigated the incidence patterns of pediatric and adolescent orthopaedic fractures according to age groups and seasons in South Korea based on population data. Methods Data on the number of pediatric and adolescent patients under the age of 18 years who utilized medical services due to fractures were retrieved from the Health Insurance Review and Assessment service in South Korea. The data included four upper extremity and two lower extremity fractures according to four age groups (0-4 years, 5-9 years, 10-14 years, and 15-18 years). Incidences of the fractures were calculated as the incidence per 10,000 per year, and patterns according to age groups and seasons were demonstrated. Results The annual incidence of clavicle, distal humerus, both forearm bone, distal radius, femoral shaft and tibial shaft fractures were 27.5, 34.6, 7.7, 80.1, 2.5, and 9.6 per 10,000 per year in children and adolescents, respectively. Clavicle and distal radius fractures showed significant seasonal variation for all age groups but femoral shaft fracture showed no significant seasonal variation for any of the age groups. Conclusions The four upper extremity fractures tended to show greater variations than the two lower extremity fractures in the nationwide database in South Korea. The study results are believed to be helpful in the planning and assignment of medical resources for fracture management in children and adolescents.

Modified Combined Approach for Distal Humerus Shaft Fracture: Anterolateral and Lateral Bimodal Approach

Background Due to the anatomical nature of the radial nerve, dissection and attainment of an adequate operative field in mid to distal humerus fracture is dangerous and limited. We devised a combined anterolateral and lateral approach that ensures protection of the radial nerve. This is achieved by performing bimodal dissection of the proximal humerus anteriorly and the distal humerus laterally. Methods Thirty-five consecutive patients were treated using a combined anterolateral and lateral approach for a minimum follow-up period of 24 months. We analyzed time to bony union, time to return to daily work, range of motion, elbow joint function as assessed by the Mayo elbow performance index and complications. Results Radiologic bony union was observed at 11.2 weeks (range, 8 to 20 weeks) on average. Four cases of incomplete radial nerve palsy before surgery all recovered. Time to return to work was 10.2 weeks (range, 2 to 32 weeks) on average. The average range of motion of the elbow was 3.3° (range, 0° to 10°) of extension and 135.9° (range, 125° to 145°) of flexion. There were 21 cases of excellent and 13 cases of good or better recovery, comprising over 97.1% on the Mayo elbow performance index. There were no complications of radial nerve palsy, non-union, mal-union, or infection. Conclusions Our a modified combined anterolateral and lateral approach is a clinically effective surgical method of achieving protection of the radial nerve and securing easy and firm internal fixation.

Prevalence of Obesity in Ambulatory Patients with Cerebral Palsy in the Korean Population: A Single Institution's Experience

Background There is a worldwide tendency of an increasing prevalence of obesity. Therefore, this study aimed at determining whether such a trend exists among cerebral palsy (CP) patients. We also tried to compare this trend with the trend in the general population. We also discuss the importance of obesity trends in CP patients. Methods This retrospective study was performed on 766 ambulatory patients who were diagnosed with CP since 1996 in our institution. The associations among the prevalence of obesity and the body mass index, age, gender, the type of CP, the gross motor function classification system and the time of survey were investigated. Results The overall prevalence of obesity was 5.7%, and the overall prevalence of obesity together with being overweight was 14.6% for the ambulatory patients with CP. The prevalence of obesity and of obesity together with being overweight did not show a statistically significant temporal increase. On the other hand, age and gender were found to affect the body mass index of the ambulatory CP patients (p < 0.001 and 0.003, respectively). Conclusions The extent of obesity and being overweight in the ambulatory patients with CP in this study was far less than that reported in the United States (US). In addition, it appears that the differences of the prevalence of obesity in children and adolescents between those with and without CP are disappearing in the US, whereas the differences of the prevalence of obesity in children and adolescents between those with and without CP seem to be becoming more obvious in Korea. Accordingly, care should be taken when adopting the data originating from the US because this data might be affected by the greater prevalence of obesity and the generally higher body mass indices of the US.

Correlation between stress shielding and clinical outcomes after total hip arthroplasty with extensively porous coated stems.

Relations between stress shielding and the clinical outcomes of total hip arthroplasty(THA) remain topics of debate. This study was performed on 51 patients that underwent unilateral primary THA with an extensively porous coated stem. Contralateral normal femurs were used as controls. Dual energy x-ray absorptiometry data was used to quantify bone mineral density(BMD) on proximal femurs. Clinical outcomes were estimated by using Harris hip scores (HHSs). BMD in operated sides were lower than in control sides. HHS and pain scores were not related to BMD changes. An extensively porous coated stem can be used for THA and that concerns regarding the effects of stress shielding of the proximal femur are unwarranted.

Incidental Findings on Knee Radiographs in Children and Adolescents

Background Despite the wide use of knee radiography in children and adolescent patients visiting the outpatient clinic, there has been no analysis about the prevalence and type of incidental findings yet. This study was performed to investigate the incidental findings on knee radiographs in children and adolescents according to age. Methods A total of 1,562 consecutive patients younger than 18 years of age were included. They who visited Seoul National University Bundang Hospitals outpatient clinic with a chief complaint of knee pain or malalignment between 2010 and 2011. We reviewed the knee radiographs and analyzed the prevalence and type of incidental findings, such as metaphyseal lucent area, epiphyseal cortical irregularity, osteochondroma and Harris growth arrest line. Results The mean age of the patients was 10.2 years (range, 1 month to 18 years). We identified 355 incidental findings in 335 patients (21.4%) and 98 abnormal findings (6.3%). The most common incidental finding was metaphyseal lucent area (131, 8.4%), followed by epiphyseal cortical irregularity (105, 6.7%), Harris growth arrest line (75, 4.8%), and osteochondroma (44, 2.8%). An epiphyseal cortical irregularity tended to have a higher prevalence at younger age (p < 0.001) and the prevalences of metaphyseal lucent area and Harris growth arrest line were also higher at a younger age (p = 0.001 and p < 0.001, respectively). However, the osteochondroma tended to have a higher prevalence at an older age (p = 0.004). Conclusions This study describes the incidental findings on knee radiographs in children and adolescents and provides effective information from a viewpoint of an orthopedic doctor. The authors recommend considering those incidental findings if unfamiliar findings appear on a knee radiograph in the pediatric outpatient clinic.

Revisit of Broden's view for intraarticular calcaneal fracture.

Background This study was performed to investigate the relationship between coronal computed tomography (CT) and Brodens view in terms of location of the fracture line and fracture pattern. Methods Forty-five feet of 45 patients with intraarticular calcaneal fractures were evaluated. The mean age of the patients was 46.3 years (standard deviation, 18.1; range, 15 to 80 years), and there were 34 men and 11 women. The Brodens views were acquired using the ray sum projection, reviewed, and correlated with the coronal CT image to determine the location of the fracture on the posterior facet and fracture pattern described by the Sanders classification. The quantified location of the fracture line was defined as the distance between the medial margin of posterior facet and the fracture line divided by the whole length of the posterior facet, which was expressed as a percentage. Results The fracture line on the Brodens view was positioned at 22.3% (standard deviation, 29.6) laterally compared to that on coronal CT (p < 0.01). Although all cases showed posterior facet involvement on the CT scan, the fracture line was positioned lateral to the posterior facet in 6 cases (13.3%) in the Brodens view. The coronal CT and Brodens view showed a low level of agreement in the fracture pattern according to the Sanders classification, with kappa values of 0.23. Conclusions Surgeons should consider that the fracture line on the Brodens view shows positioning laterally compared to coronal CT and they should consider that the fracture line at the lateral to posterior facet on the Brodens view might be an intraarticular fracture line. There are some limitations when applying the Sanders classification with the Brodens view.

Clinical Characteristics of Methicillin-resistant Staphylococcus aureus Infection for Chronic Periprosthetic Hip and Knee Infection.

Purpose Deep infection after hip and knee arthroplasty is a serious complication and is difficult to treat due to its toxicity. The aims of our study were to find out the differences of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) infection after hip and knee arthroplasty focusing on clinical course and laboratory findings. Materials and Methods We retrospectively reviewed 61 staphylococcal infection cases after hip and knee arthroplasty (MSSA in 25 patients, MRSA in 36 patients). Vital signs, laboratory tests, microbiology and clinical courses were analyzed. The average follow-up period was 3.8 years (range, 2 to 10.1 years). Results At initial visit, MRSA group showed significant higher erythrocyte sedimentation rate, C-reactive protein (CRP) and neutrophil percentage. The average duration for the normalization of CRP was longer in MRSA group (MRSA: 36.7±25.1 days, MSSA: 24.7±13.6 days; P=0.008). The mean interval between staging operation was longer in MRSA group (MRSA: mean 8.7 weeks [range, 6.4 to 21.4 weeks], MSSA: mean 6.8 weeks [range, 6 to 13.1 weeks]; P=0.012). MRSA group (13.9%) revealed higher recurrence rate than MSSA group (4%). Two patients (5.6%) from MRSA group expired by sepsis. One limb amputation (2.7%) was carried out in MRSA group. Conclusion MRSA infection after arthroplasty showed more toxic serologic parameter and poorer prognosis. Aggressive treatment should be considered for MRSA infection following arthroplasty.