PURPOSE: This paper is proposing an improved CT-free registration method which may provide us an accurate and reliable placement of acetabular cup without CT/MRI images. DESIGN AND METHODS: The proposed method employs a T-bar shaped gauge placed on the anatomical landmarks of the pelvis for the registration. The T-bar shaped gauge has its own LED markers and the position of the gauge is obtained through OPTOTRAK3020 system. These landmark points are the anterior superior iliac spines and the symphysis pubis defining anterior pelvic plane. Two subjects were tested to compare the landmark based registration and the proposed T-bar based registration. RESULTS: The measurement deviations of the pelvic obliquity in the frontal plane, tilt in the sagittal plane, and rotation in the transverse plane were 2.08, 1.41, and 2.51 degrees respectively in the point based registration. The T-bar based registration produced 40% smaller deviations(p<0.05): the pelvic obliquity in the frontal plane, tilt in the sagittal plane, and rotation in the transverse plane were 0.84, 0.81, and 1.17 degrees respectively in the T-bar based registration. There was no outlier exceeding 5 degrees in measurement deviation by the T-bar based registration while the outliers were found by the landmark based registration. CONCLUSIONS: We found that T-bar based CT free registration method is more reliable and accurate than the landmark based registration for the acetabular cup navigation. Also, the new method produced more precise registration(p<0.05). We are expecting some offset error of the new registration method due to the skin thickness existing between the T-bar frame and the bony pelvic frame, which may be compensated if we may accumulate sufficient database of the offset.
Acetabulum ; Arthroplasty, Replacement, Hip* ; Pelvis ; Skin ; Spine

PURPOSE: To propose a method providing an accurate femoral shaping for cementless total hip arthroplasty to maximize bone contact without femoral bone breakage and make secure correct position of the implant by eliminating the manual broach process MATERIALS AND METHODS: 5-cadaver specimens were tested with this system. A reamer-shaped registration gauge is inserted into the femoral canal. This gauge defines the position of the implant to be inserted. Then, the base frame is attached to the femur and the position of the gauge with respect to the base frame is measured. After removing the gauge, a mini robot is mounted on the frame and shapes the femoral canal. After the milling operation, model implant is inserted and its position and gap are measured. RESULTS: Anteversion angle error was 0.9degrees(S.D.1.7) and Varus/Valgus alignment error was 1.1degrees(S.D.1.5). 95%(S.D. 3.2) of contact surface had less than 0.3mm gap error. CONCLUSIONS: Proposed THA surgery system increased the accuracy of stem position and fitness compared with manual operation. Our mini robot THA surgery provides most of the benefits RobodocR does while operating procedure is much more simplified and economic.
Arthroplasty, Replacement, Hip* ; Cadaver* ; Femur

A statistical observation was made on 371 in-patients with age distribution, disease entities and operative procedures in the department of Urology, Seoul Red Cross Hospital, during the period from January 1st, 1974 to December 31st, 1976.
Age Distribution ; Red Cross ; Seoul ; Surgical Procedures, Operative ; Urology

PURPOSE: To compare the variable inflammatory parameters of acute pyelonephritis patients treated with inpatient therapy at 13 hospitals, according to the age and gender distributions. MATERIALS AND MATHODS: A total of 3,544 medical records of patients with confirmed acute pyelonephritis, and admitted to hospital between January 2000 and December 2005, were retrospectively analyzed. RESULTS: The mean age of the patients was 43.2+/-16.2 years old, with a male:female ratio of 1 : 5.1. The average duration of hospital admission was 7.9+/-5.3 days. Underlying diseases were found in 23.0% (749/3,252 patient), largely due to diabetes (35.1%). Radiological abnormal findings were found in 13.7%. The leukocyte count, ratio of segmented form, erythrocyte sedimentation rate (ESR), c-reactive protein, pyuria, positive blood culture, positive urine culture were 11,014+/-5,778/mm(3), 74.8+/-14.5%, 44.0+/-32.0 mm/hr, 12.4+/-9.3mg/dl, 83.9%, 10.5% and 46.7%, respectively. E. coli grow in 79% of the urine culture positive patients. In a comparison of 3 age groups (<40 years, 40-60 years, >61 years), the elderly patients had a greater number of underlying diseases and more pathogens in cultured blood. When divided into males and females, the elderly male patients had more pathogen in cultured urine, but contrary to the male patients, the elderly female patients had elevated leukocyte count and erythrocyte sedimentation rate. Also, the old patient group had more resistance to ampicillin when they had E. coli as the uropathogen (p=0.021). Patients with higher ESR required longer hospital admission periods. CONCLUSIONS: It was found that variable clinical parameters of acute pyelonephritis patients treated with inpatient therapy differed according to both gender and age group in Korea. Therefore, these factors should be taken into account in the treatment plan.
Aged ; Ampicillin ; Blood Sedimentation ; C-Reactive Protein ; Female ; Humans ; Inpatients ; Korea ; Leukocyte Count ; Male ; Medical Records ; Pyelonephritis* ; Pyuria ; Retrospective Studies