Degeneration of Acetabular Articular Cartilage to Bipolar Hemiarthroplasty

PURPOSE: This study examined the rate of degeneration of acetabular cartilage by the bipolar head according to time, and also which clinical factors are related to the degeneration of acetabular cartilage. MATERIALS AND METHODS: Among 192 patients (226 hip joints) who received bipolar hemiarthroplasty from August 1996 to August 2002, 61 patients (65 hip joints) were enrolled in this study, who were followed up for more than 2 years and showed no signs of dislocation, infection, or functional problems. A modified form of a computer assisted vector wear analysis program was used to measure the rate of degeneration of the acetabular cartilage. The factors that appeared to affect the rate of acetabular degeneration in the two groups was evaluated. RESULTS: The average linear degenerative change in the acetabular cartilage and the volumetric degenerative change were 0.23 +/- 0.107mm/year and 114 +/- 47.2mm3/year, respectively. The result showed significant differences in activity and HHS between the 2 groups. The HHS showed a reverse relationship with the linear degeneration and volumetric degeneration, and the activity showed a correlation with the linear and volumetric degeneration. CONCLUSION: The acetabular cartilage degenerates faster as the patient' activity increases, and slower with a higher HHS. When surgeons perform hip joint arthroplasty, it is strongly recommended that the life expectancy and the level of activity should be considered when deciding between a hemiarthroplasty and total hip arthroplasty.

Analysis of Risk Factors Affecting Degeneration of the Acetabular Cartilage after Bipolar Hemiarthroplasty

PURPOSE: This study attempted to investigate the rate of acetabular cartilage wear, as well as the risk factors that are related to degeneration, for patients who were diagnosed with femur neck or intertrochanteric fracture and who underwent bipolar hemiarthroplasty. MATERIALS AND METHODS: 34 patients who were diagnosed with femur neck or intertrochanteric fracture and who underwent bipolar hemiarthroplasty were selected as the study subjects, and they were followed up for more than 2years. We examined potential relationships between the degeneration of acetabular cartilage and the various risk factors by comparing radiographs taken before and after operations. RESULTS: After bipolar hemiarthroplasty, the average degenerative change in the acetabular cartilage was 0.20 mm/yr. Specifically, the average appeared significantly different according to gender (p=0.039, Male: 0.26 mm/yr, Female: 0.19 mm/yr), age (p=0.02, the under 70-year olds: 0.29 mm/yr, the upper 70-year olds: 0.13 mm/yr), the life style, (p=0.037, the stand-up life style: 0.18 mm/yr, the sit-down life style: 0.24 mm/yr), (ED note: stand up and sit down made no sense.) and using femoral stem cementing (p=0.237, cement: 0.22 mm/yr, non-cement: 0.21 mm/yr). The bone mineral density score (p=0.254), activity score (p=0.041), HHS (p=0.027) and femoral stem alignment (p=0.438) were shown to be -3.7, 3.2, 87 and varus 1 degree for people with less than average degeneration of the acetabular cartilage and -3.9, 4.3, 75 and varus 2 degrees for people with more than average degeneration of the acetabular cartilage, respectively. CONCLUSION: The results showed no significant relationship between degeneration of the acetabular cartilage and patient gender, the presence of osteoporosis and using femoral stem cement. The degeneration of acetabular cartilage was faster for young patients, for patients with a sit-down life style, for a higher activity score or for a lower HHS. It is strongly recommended for surgeons to consider the patients' various conditions such as age, activity and a sit-down lifestyle when deciding between hemiarthroplasty and total hip arthroplasty.

Degeneration of the Acetabular Articular Cartilage to Bipolar Hemiarthroplasty / 대한정형외과학회잡지

PURPOSE: This study examined the rate of degeneration of the acetabular cartilage by the bipolar head according to time, and which clinical factors are related to the degeneration of the acetabular cartilage. MATERIALS AND METHODS: Among 192 patients (226 hip joint) who were received bipolar hemiarthroplasty from August 1996 to August 2002, 61 patients (65 hip joint), who were followed up for more than 2 years and showed no signs of dislocation, infection and functional problems, were enrolled in this study. A modified form of a computer assisted vector wear analysis program was used to measure the rate of degeneration of the acetabular cartilage. The subjects were divided into two groups, those whose amount of degeneration of the acetabular cartilage was less than average and those whose amount of degeneration was more than average. The factors that appeared to affect the level of acetabular degeneration in the two groups were evaluated. RESULTS: After a bipolar hemiarthroplasty, the average linear degenerative change in the acetabular cartilage and the volumetric degenerative change was 0.23+/-0.107 mm/yr and 114+/-47.2 mm3/yr, respectively. The result showed significant differences with activity and the HHS between the two groups. The HHS showed a reverse relationship with the linear degeneration and volumetric degeneration, the activity showed a correlation with the linear and volumetric degeneration. CONCLUSION: The acetabular cartilage degenerates faster as the patient's activity increases, and slower with a higher HHS. When surgeons perform hip joint arthroplasty, it is strongly recommended that the life expectancy and the level of activity be considered when deciding between a hemiarthroplasty or total hip arthroplasty.

Acetabular Degeneration in Osteonecrosis of the Femoral Head / 대한정형외과학회잡지

PURPOSE: To determine the degree of acetabular cartilage degeneration and factors that influence acetabular cartilage degeneration in osteonecrosis of the femoral head (ONFH). MATERIALS AND METHODS: We obtained acetabular cartilage from weight bearing and non-weight bearing portions, including subchondral bone, from 34 hips in 32 patients with ONFH who underwent total hip arthroplasty. Histologic grading by Hematoxylin & Eosin staining and Safranin O staining, and immunohistochemical staining with chondroitin sulfate antibody and type II collagen antibody were performed. RESULTS: Histological grade had no significant correlation with stage, age, weight, or duration or degree of head depression, by the Wilcoxon rank sum test. The weight bearing and the non-weight bearing portions of acetabular cartilage were divided into two groups according to the existence and non-existence of femoral head depression. A significant difference (p=0.01), by Fisher's exact test, was found between the two weight bearing groups in terms of histologic grade. However no significance (p=0.45) was found between the two non-weight bearing groups. The distribution of type II collagen antibody's stainability score show most values in the normal range, while that of chondroitin sulfate antibody's was mainly in the upper. CONCLUSION: The degeneration of the weight bearing portion of acetabular cartilage in ONFH is considered to be due to local rather than general changes. When head depression in absent, acetabular cartilage degeneration is less severe than previously reported.

The Reaction of the Acetabular Articular Cartilage to Bipolar Hemiarthroplasty

An evaluation of the acetabular cartilage was performed grossly and histologically in a patient who had a bipolar hemiarthroploasty, which had served satisfactorily for 2 years until the femoral prosthetic head had been separated from the acetabular assembly due to creep deformation of the inner bearing polyethylene cup. This study indicates that the double-bearing bipolar prosthesis dose not necessarily have an advantage over the classical single-piece prosthesis in the prevention of acetabular cartilage wear.