RF Transceiver for the Multi-Mode Radar Applications.

In this work, a multi-mode radar transceiver supporting pulse, FMCW and CW modes was designed as an integrated circuit. The radars mainly detect the targets move by using the Doppler frequency which is significantly affected by flicker noise of the receiver from several Hz to several kHz. Due to this flicker noise, the long-range detection performance of the radars is greatly reduced, and the accuracy of range to the target and velocity is also deteriorated. Therefore, we propose a transmitter that suppresses LO leakage in consideration of long-range detection, target distance, velocity, and noise figure. We also propose a receiver structure that suppresses DC offset due to image signal and LO leakage. The design was conducted with TSMC 65 nm CMOS process, and the designed and fabricated circuit consumes a current of 265 mA at 1.2 V supply voltage. The proposed transmitter confirms the LO leakage suppression of 37 dB at 24 GHz. The proposed receiver improves the noise figure by about 20 dB at 100 Hz by applying a double conversion architecture and an image rejection, and it illustrates a DC rejection of 30 dB. Afterwards, the operation of the pulse, FMCW, and CW modes of the designed radar in integrated circuit was confirmed through experiment using a test PCB.

Descriptive Epidemiology of Patients Undergoing Total Hip Arthroplasty in Korea with Focus on Incidence of Femoroacetabular Impingement: Single Center Study.

We analyzed the causes leading to total hip arthroplasty (THA), aimed to clarify the incidence of femoroacetabular impingement (FAI) among the causes, and compared the incidence in Korea with those in other countries. From January 2000 to December 2014, 1,206 hips of 818 patients who underwent primary THA at our institute were reviewed retrospectively in terms of radiographs and electronic charts. The radiographs and radiographic parameters were reviewed and measured by 2 of the authors, who are orthopedic surgeons. Patients were categorized in terms of the causes leading to THA as primary osteoarthritis (OA), rheumatoid arthritis (RA), posttraumatic arthritis, post infectious arthritis, avascular necrosis (AVN) of the femoral head, fracture of the femoral head or neck, ankylosing spondylitis (AS), developmental dysplasia of the hip (DDH), Legg-Calvé-Perthes disease (LCPD), FAI, and others. There were 32 patients (3.91%) in the primary OA group, 41 (5.01%) in the RA group, 84 (10.27%) in the posttraumatic arthritis group, 39 (4.77%) in the post infectious arthritis group, 365 (44.62%) in the AVN group, 39 (4.77%) in the fracture group, 21 (2.57%) in the AS group, 52 (6.36%) in the DDH group, 71 (8.68%) in the LCPD group, 52 (6.36%) in the FAI group, and 22 (2.69%) in the 'other' group. The causes leading to THA in Korea differ from those in Western countries. FAI could be causes of severe secondary OA that requires THA in Korea, therefore symptomatic FAI should not be neglected.

Comprehensive Review of Advancements in Hip Arthroscopy.

Hip arthroscopy is currently being leveraged in the diagnosis and treatment of a wide range of hip joint problems. In fact, great advancements in hip arthroscopy have resulted in an ever-expanding number of indications to which it is being applied. Minimally invasive hip arthroscopy allows for quicker initiation of rehabilitation and has attracted much attention as the field becomes increasingly focused on surgeries designed to preserve joints. This review aims to summarize the recent advances, applications, and impact of hip arthroscopy.

Hip Arthroscopy for Incarcerated Acetabular Labrum following Reduction of Traumatic Hip Dislocation: Three Case Reports.

Traumatic hip fracture-dislocations are associated with chondral and labral pathology as well as loose bodies that can be incarcerated in the hip joint. Incarceration, such as interposed labrum between acetabulum and femoral head that is not readily visualized preoperatively, is a rare but important cause of pain and can potentially be a source for early degeneration and progression to osteoarthritis. We present three cases, arthroscopic surgery of incarcerated acetabular osseo-labral fragment following reduction of traumatic hip fracture-dislocation.

Could Patient Undergwent Surgical Treatment for Periprosthetic Femoral Fracture after Hip Arthroplasty Return to Their Status before Trauma?

PURPOSE: The purpose of this study was to compare preoperative clinical outcomes before occurrence of periprosthetic femoral fracture (status before trauma) with postoperative clinical outcomes (status after operation) in patients with periprosthetic femoral fracture after hip arthroplasty. MATERIALS AND METHODS: A retrospective review was performed of all periprosthetic femoral fracture after hip arthroplasty treated surgically at our institution from January 2010 to January 2014. Among 29 patients who underwent surgical treatment for periprosthetic femoral fracture after hip arthroplasty, 3 patients excluded because of non-union of the fracture site. The clinical outcomes were determined by using visual analogue scale for pain (VAS), Harris hip score (HHS), and ambulatory ability using Koval classification. VAS, HHS and ambulatory ability was assessed for all the included patients at the last follow-up of status before trauma and after operation. RESULTS: The mean VAS, HHS and ambulatory ability at the last follow-up of status before trauma was 2.2 (range, 0-4), 78.9 (range, 48-92) and 1.9 (range, 1-5), respectively. The mean VAS, HHS and ambulatory ability at the last follow-up of status after operation was 3.1 (range, 1-5), 68.4 (range, 46-81) and 2.9 (range, 2-6), respectively. The clinical outcome of VAS, HHS and ambulatory ability were significantly worsened after surgical treatment for periprosthetic femoral fracture (P=0.010, P=0.001, and P=0.002, respectively). CONCLUSION: Patients with periprosthetic femoral fracture after hip arthroplasty could not return to their status before trauma, although patients underwent appropriate surgical treatment and the fracture union achieved.

The Optimal Suture Site for the Repair of Posterior Horn Root Tears: Biomechanical Evaluation of Pullout Strength in Porcine Menisci.

PURPOSE: There are few studies on biomechanical evaluation of suture points in repair of root tears. The purpose of this study was to determine the point of greatest pullout strength for root tear repair. MATERIALS AND METHODS: A total of 120 fresh porcine medial menisci were obtained. The red-red and red-white zones of the meniscus were divided by two lines designated as lines A and B (groups A and B). Groups A and B were further divided into three groups each by dividing lines A and B into three points: 3, 5, and 7 mm from the meniscal ligament root insertion. Vertical meniscal repair was performed on each point. The pullout failure strength was tested using a biaxial servohydraulic testing machine. RESULTS: The average maximal load at failure was significantly greater in group A than group B (87.65 vs. 62.93; p<0.001) The average length at maximal load failure was greater in group A than group B (4.35 vs. 3.2; p<0.001). Among the subgroups of 3, 5, and 7 mm in both groups A and B, 7 mm showed the greatest maximal load (p<0.001). CONCLUSIONS: The pullout strength was statistically significantly greater in group A than group B and in the 7 mm subgroup than the 3 and 5 mm subgroups. Thus, the 7 mm subgroup in group A showed the greatest pullout strength.

Temporary scaphocapitate fixation with or without radial shortening for adolescent Kienböck's disease.

We performed temporary scaphocapitate joint fixation with or without radial shortening osteotomy, depending on the ulnar variance, in adolescent Kienböck's disease. The aim of the current study was to evaluate the radiological and clinical results and compare our results with those of other previously reported methods. Temporary scaphocapitate fixation alone or fixation accompanied by radial shortening osteotomy has been performed in three patients since 2003. All six patients were males, and their mean age at surgery was 15.5 years. The fixation was performed using two Kirschner-wires in closed methods, and the shortening of the radius was performed using the volar approach and secured with a plate. Radial shortenings of 4, 2, and 7 mm were applied. Radiological findings of Kienböck's disease, including ulnar variance and carpal height ratio, were investigated at the final follow-up by simple radiography and MRI. Clinical results of pain, range of wrist motion, and grip strength were also evaluated. The mean age at the final follow-up of six patients was 22 years, and the follow-up period was 6.8 years. Sclerosis or fragmentation of all the lunates in the simple radiographs improved, and the carpal height ratio increased to 0.5 at the final follow-up. The signal intensities on the final MRI were all normalized. The final visual analog scale scores decreased to 1.2, and wrist ranges of motion were all statistically significantly increased. In addition, grip strength increased to 69% of that of the normal side at the final follow-up. We suggest that temporary scaphocapitate joint fixation is a recommendable option with or without radial shortening, depending on the ulnar variance, in adolescent Kienböck's disease.

Arthroscopic Treatment of Subchondral Bony Cyst in Early Osteoarthritis of the Hip Joint Using Allogeneic Bone Graft: A Report of Two Cases.

Subchondral bony cyst, large solitary or multiple cysts in acetabular dome usually exacerbate progression to degenerative osteoarthritis in the hip joint. But it can be treated through arthroscopic intervention. We report two cases that treated by arthroscopic curettage and bone graft for subchondral bony cysts in early osteoarthritis of the hip joint, and it may delay progression to moderate osteoarthritis.

Fixation of posterior process fractures of the olecranon using a modified suture bridge technique: report of 2 cases.

We encountered 2 patients with posterior process fractures of the olecranon and fixed the fragment using a modified suture bridge method without a metallic implant. The suture anchor was inserted distally through the fracture plane, and the small tip of proximal olecranon was reduced to the ulna. Computed tomography revealed bony union 4 and 5 months later. At the 1-year postoperative follow-up examination, the clinical outcomes were satisfactory in both patients. This suture bridge technique was reliable for small fragment fixation in posterior process fracture of the olecranon based on the tension band theory with no problems induced by metallic hardware.