Hyoung Keun Oh

Factors contributing to inherent varus alignment of lower limb in normal Asian adults: role of tibial plateau inclination.

PURPOSE This prospective study aimed to evaluate radiographically, mechanical or hip-knee-ankle (HKA) axis in healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40 years of age to determine the incidence of inherent varus (mechanical limb alignment of >3° varus) and the factors influencing it. METHODS Three hundred and eighty-eight lower limbs were evaluated using full length, standing hip-to-ankle radiographs in 198 healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40 years of age to assess the hip-knee-ankle (HKA) angle, medial proximal tibial angle (MPTA), femoral bowing and femoral neck-shaft angle to determine the incidence of inherent varus (mechanical limb alignment of >3° varus) and the factors influencing it. RESULTS Overall, the mean HKA angle was 177.6°±2.6° with 34.5% of limbs in inherent varus (mean HKA angle 174.9°±1.8°). The incidence of inherent varus was significantly higher (p=0.01) in males (40%) compared to females (28%) but similar among Indian (34%) and Korean subjects (35%). The hip-knee-ankle (HKA) angle showed significant positive correlation (r=0.82, p<0.001) with only the medial proximal tibial angle (MPTA). CONCLUSIONS Inherent varus alignment of the lower limb is fairly common among asymptomatic, Asian adults. These results raise several pertinent questions regarding the role of inherent varus in the aetiopathogenesis of knee osteoarthritis and in lower limb realignment procedures.

Challenge to treat hypertrophic nonunion of the femoral shaft: the Poller screw augmentation technique

The management of a femoral nonunion after intramedullary nailing is challenging. Exchange nailing or plate augmentation has been used to treat hypertrophic nonunions previously. The Poller screw augmentation technique is a simple procedure that can be performed in the outpatient surgery. In this study, we highlight the method of hypertrophic nonunion management according to the specific indication including our Poller screw augmentation technique.

Factors affecting fracture location in atypical femoral fractures: A cross-sectional study with 147 patients

INTRODUCTION Many studies have tried to determine the characteristics of atypical femoral fractures (AFFs) through age-, sex-, and ethnicity-matched comparison with non-AFFs. However, we hypothesized that diaphyseal AFFs would have characteristics different from those of subtrochanteric AFFs. The aim of this study was to evaluate the clinical features of diaphyseal/subtrochanteric AFFs and determine the factors related to fracture location. PATIENTS AND METHODS One hundred forty-seven patients with AFF were enrolled, 114 patients (78%) had a history of bisphosphonate use. Forty-nine patients (33%) had bilateral lesion, and 35% of patients had thigh pain. Patients were divided into two groups according to fracture location: 52 patients (35.4%) with subtrochanteric AFF and 95 patients (64.6%) with diaphyseal AFF. The patient demographics and fracture characteristics of the two groups were compared. Multivariate logistic regression analysis was used to adjust for variables related to fracture location. RESULTS The patients in the diaphyseal AFFs group were older and had lower BMI, lower BMD, and larger lateral and anterior bowing. Multivariate analysis revealed that age greater than 65 years and low BMD were related with diaphyseal location. With greater lateral bowing angle, the AFF location was moved from the subtrochanteric area to the diaphyseal area. CONCLUSION This study demonstrated that patients with diaphyseal AFFs had different characteristics compared with those with subtrochanteric AFFs.

Internal fixation of displaced inferior pole of the patella fractures using vertical wiring augmented with Krachow suturing

BACKGROUND We present the surgical technique of separate vertical wiring for displaced inferior pole fractures of the patella combined with Krachow suture and report the surgical outcomes. MATERIALS AND METHODS Between September 2007 to May 2012, 11 consecutive patients (mean age, 54.6 years) with inferior pole fractures of the patella (AO/OTA 34-A1) were retrospectively enrolled in this study. Through longitudinal incision, all patients underwent open reduction and internal fixation by separate vertical wiring combined with Krackow suture. The range of motion, loss of fixation, and Bostman score were primary outcome measures. RESULTS The union time was 10 weeks after surgery on average (range: 8-12). No patient had nonunion, loss of reduction and wire breakage. There was no case of wound problem and irritation from the implant. At final follow-up, the average range of motion arc was 129.4° (range: 120-140). The mean Bostman score at last follow-up was 29.6 points (range: 28-30) and graded excellent in all cases. CONCLUSION Separate vertical wiring combined with Krackow suture for inferior pole fractures of the patella is a useful technique that is easy to perform and can provide stable fixation with excellent results in knee function.

Arthroscopic Transpatellar Cannulated Screw Fixation of Tibia Eminence Fractures in the Adult

Arthroscopic transpatellar screw fixation with a cannulated screw and washer is a simple, effective, and safe technique providing stable fracture fixation to allow immediate mobilization with minimal loss of extension in type II and III tibial eminence fractures in adults.

Incidence of Avascular Necrosis of the Femoral Head After Intramedullary Nailing of Femoral Shaft Fractures: A Multicenter Retrospective Analysis of 542 Cases.

Abstract The goal of this study was to determine the incidence of avascular necrosis of the femoral head (AVNFH) after intramedullary nailing of femoral shaft fractures and to identify risk factors for developing AVNFH. We retrospectively reviewed all patients with femoral shaft fractures treated with antegrade intramedullary nailing at 10 institutions. Among the 703 patients enrolled, 161 patients were excluded leaving 542 patients in the study. Average age was 42.1 years with average follow-up of 26.3 months. Patient characteristics and fracture patterns as well as entry point of femoral nails were identified and the incidence of AVNFH was investigated. Patients were divided into 2 groups according to open versus closed physis, open versus closed fractures, and age (<20 versus ≥20 years). Overall incidence of AVNFH was 0.2% (1 of 542): the patient was 15-year-old boy. Of 25 patients with open physis, the incidence of AVNFH was 4%, whereas none of 517 patients with closed physis developed AVNFH (P < 0.001). The incidence of AVNFH in patients aged < 20 versus ≥20 years was 1.1% (1 of 93) and 0.0% (0 of 449), respectively (P = 0.172), which meant that the incidence of AVNFH was 0% in adult with femur shaft fracture. Of 61 patients with open fractures, the incidence of AVNFH was 0%. The number of cases with entry point at the trochanteric fossa or tip of the greater trochanter (GT) was 324 and 218, respectively, and the incidence of AVNFH was 0.3% and 0.0%, respectively (P = 0.412). In patients aged ≥20 years with isolated femoral shaft fracture, there was no case of AVNFH following antegrade intramedullary nailing regardless of the entry point. Therefore, our findings suggest that the risk of AVNFH following antegrade femoral nailing is extremely low in adult patients.

Measurement of Optimal Insertion Angle for Iliosacral Screw Fixation Using Three-Dimensional Computed Tomography Scans

Background Percutaneous iliosacral screw fixation can provide stable fixation with a minimally invasive surgical technique for unstable posterior pelvic ring injuries. This surgical technique is not limited by cases of difficult fracture patterns, sacral dysplasia, and small sacral pedicles that can occur in Asians. The purpose of this study was to investigate the incidence of the sacral dysplasia in the Korean population and determine the optimal direction of iliosacral screws by analyzing pelvic three-dimensional computed tomography (3D-CT) scans. Methods One hundred adult patients who had pelvic 3D-CT scans were evaluated. The upper sacral morphology was classified into three groups, i.e., normal, transitional, and dysplastic groups; the cross-sectional area of the safe zone was measured in each group. S1 pedicle with a short width of more than 11 mm was defined as safe pedicle. The incidences of safe pedicles at different angles ranging from 0° to 15° were investigated in order to determine optimal angle for screw direction. Results The incidence of normal, transitional, and dysplastic group was 46%, 32%, and 22%, respectively. There were significant increases of the cross-sectional area of the safe zones by increasing the angles from 0° to 15° in all groups. The incidence of safe pedicles increased similar to the changes in cross-sectional area. The overall incidence of safe pedicles was highest at the 10° tilt angle. Conclusions The incidence of sacral dysplasia in Koreans was 54%, which is higher than previous studies for Western populations. The cross-sectional area of the safe zone can be increased by anteromedial direction of the iliosacral screw. Considering the diversity of sacral morphology present in the Korean population, a tilt angle of 10° may be the safest angle.