Hyun Chul Shon

Clinical experience with three-dimensional printing techniques in orthopedic trauma

BACKGROUND To report our experiences with the use of three-dimensional (3D) printing in the field of orthopedic trauma. METHODS This retrospective study enrolled 24 patients from three university teaching hospitals in whom 3D printing technique was applied: 14 patients with acetabular fractures and 10 patients with clavicular shaft fractures. We summarized our experiences with 3D printed bone models. RESULTS Three-dimensional printed acetabular models improved understanding of complex acetabular anatomy and fracture pattern to plan the optimal positioning of a reduction clamp and the trajectory of screws. Pre-bending of a reconstruction plate could reduce operative time. We also recorded fluoroscopic images of a simulated surgery for percutaneous screw fixation of the acetabular posterior column, with the optimal positioning of the guide wire determined during the simulation used as a reference during the actual operation. This surgical simulation was performed by a resident and served as a helpful training method. For fractures of the clavicle, we identified the optimal position of anatomical plates using 3D printed clavicle models. CONCLUSION In our experience, 3D printing technique provided surgeons with improved understanding of the fracture pattern and anatomy and was effectively used for preoperative planning, education of surgical trainees, and performing simulations to improve intra-operative technical outcomes.

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.

How can MRI change the treatment strategy in apparently isolated greater trochanteric fracture

INTRODUCTION The purpose of this study was to evaluate the proportion of greater trochanter (GT) fractures with occult extension to the intertrochanteric region on magnetic resonance imaging (MRI) among apparently isolated GT fractures and to investigate the use of MRI for formulating a treatment strategy in patients with isolated GT fractures. PATIENTS AND METHODS This retrospective cohort study reviewed 37 patients with isolated GT fractures on plain radiography. Surgical or conservative treatment was decided according to MRI findings. We divided patients into 3 groups according to the extension of the fracture line. In group 1, the fracture line was within the lateral one-third in the coronal plane. In group 2, the fracture line extended from the lateral one-third to the medial one-third. In group 3, the fracture line extended over the medial one-third and/or to the medial cortex of the femur. Conservative treatment was performed in groups 1 and 2, and surgical treatment was performed in group 3. The clinical results, radiography findings, and MRI findings were investigated. RESULTS MRI revealed hidden intertrochanteric fractures (groups 2 [n = 10] and 3 [n = 4]) in 38% of apparently isolated GT fractures on radiography. No displacement was found in groups 1 (n = 23) and 2. Of the 4 patients in group 3, 3 were treated surgically and achieved good functional results and 1 refused to undergo surgery and finally developed complete intertrochanteric fracture. This patient presented 5 days later with increased hip pain, and radiography demonstrated displacement of the fracture, prompting surgical intervention. CONCLUSIONS The evaluation of apparently isolated GT fractures using MRI can be useful to diagnose the extent of the occult fracture and determine the treatment strategy.

Cauda Equina Syndrome by Lumbar Disc Herniation after Caesarian Section Delivery - A Case Report -

Cauda equina syndrome develops as rapidly progressive neurologic deficit of lower extremities and urogenital system often resulting in serious outcome such as complete irreversible paraparesis. Therefore prompt diagnosis and decompression is mandatory. However, if it occurs after childbirth, it may be overlooked being regarded as symptoms related to pregnancy and delivery. We experienced a cauda equina syndrome by ruptured disc in a 32-year-old woman just after Caesarian section in a local obstetric clinic who was transferred to us 2 days after development of progressive neurologic deficits. We managed her with prompt decompressive surgery and achieved favorable result. Because of the importance of early detect and prompt decompression for cauda equina syndrome and possible occurrence at perinatal period, we report this case reviewing the literature especially concerning about pregnancy and cauda equina syndrome.

Analysis of West Point View in Anterior Shoulder Instability

Purpose : To evaluate the usefulness of the West point view, we investigated the osseous pathology of the glenoid rim associated with shoulder instability and estimate the inter-observer reliability. Materials and Methods : The West point views of sixty-seven patients with labral lesion confirmed by operation were mixed with those of thirty-three normal controls. Six observers independently reviewed the mixed radiographs and checked the lesion by identifying the glenoid erosion, bony defect, ectopic ossification and Hill-Sachs lesion. The incidence of osseous lesions suggest-ing instability was estimated. Sensitivity in the patient group, specificity in the normal control and inter-observer reliability were cal-culated to evaluate study susceptibility. Results : The sensitivity of 67 patients group was 81.8% on average (73-94%), the specificity of 33 member control group was 85.2% (82-94%). The most frequent finding was glenoid erosion, with an average of 54.7%, which providing a sensitive clue of shoul-der instability. Inter-observer reliability analyzed by using Kappa values showed significant agreement. (=0.1 significant level). Conclusion : The West point view is considered to be a reliable diagnostic modality for shoulder instability. The additional sophisticated method is indicated only when a discrepancy between physical examination and radiologic findings exists.