Femoral head density on CT scans of patients following hip fracture fixation by expandable proximal peg or dynamic screw (original) (raw)
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International Orthopaedics, 2008
Recently it was shown that the design changes from the ABG-I to ABG-II hip stem resulted in a better, although not significant, proximal bone preservation. Our hypothesis was that by matching patients for preoperative bone quality, statistical power would increase and that the trend of better proximal bone preservation in ABG-II might become significant. Twenty-four ABG-II patients were compared to two different ABG-I groups: (1) 25 patients from our earlier prospective study and (2) a group of 24 patients selected to perfectly match the ABG-II group regarding gender, age and preoperative bone quality. Postoperative changes in periprosthetic bone mineral density (BMD) were quantified at 2 years postoperatively using DEXA scanning. Bone preservation (less BMD loss) was better for the ABG-II than the ABG-I (all two groups) in the proximal zones 1 and 7. In Gruen zone 7, a statistically significant difference was found for group B (p=0.03). By matching patients for preoperative bone quality and gender, a statistical significant difference was found in proximal bone preservation in favour of ABG-II. In future comparative bone remodelling studies using DEXA, patients should be matched for preoperative bone quality and gender. Résumé Il a été démontré, récemment, que le changement de la pièce fémorale entre l'ABG-1 et l'ABG-2 entraînait une amélioration de la préservation du stock osseux mais ceci n'était pas significatif. En étudiant une série de patients, nous avons souhaité démontrer l'inverse. 24 patients avec une prothèse ABG-2 ont été comparés à différents groupes de patients avec une prothèse ABG-1: (1) 25 patients de notre étude prospective et (2) un groupe de 24 patients sélectionnés, avec une série parfaitement cohérente en termes de sexe, d'âge et de qualité osseuse préopératoire. Les modifications de la densité minérale osseuse (BMD) ont été mesurées à deux ans post opératoires en utilisant la technique DEXA. La préservation du capital osseux est meilleure dans l'ABG-2 que dans l'ABG-1 (y compris dans les deux groupes) au niveau de la partie proximale en zones 1 et 7. Dans la zone 7 de Gruen une différence significative a été trouvée pour le groupe B (p=0.03). Cette étude montre qu'avec une bonne sélection de patients on peut mettre en évidence que la conservation osseuse est meilleure pour l'ABG-2. Dans une étude ultérieure, nous essayerons d'évaluer, selon la technique DEXA le capital osseux en sélectionnant des patients en préopératoire selon la qualité de l'os et le sexe.
Bone loss around failed femoral implant measured by dual-energy X-ray absorptiometry
2000
quantity of bone near a metallic implant. 5,6,8 Changes not already visible on standard X-ray films can be detected with DXA. 1 Radiation for the patient is minimal (under 5 mrem/scan), 7 and the error in repetitive measurements is also small 1.0%-5.3%. 8 Periprosthetic bone loss around failed total hip arthroplasty (THA) has not, however, been quantitated so far. The aim of this study was to measure bone mineral density (BMD) around the loosened femoral stem, using DXA to establish a quantative model of bone loss around the loosened implant. Patients and methods Between December 1993 and August 1997, BMD measurements were performed preoperatively in 30 patients who came for revision THAs at Kuopio University Hospital. Nineteen of these patients (13 women, 6 men) had been unilaterally operated on and were selected for this study. The indication for primary arthroplasty was primary arthrosis in 79% (15/19) of the patients, hip fracture in 16% (3/19), and secondary arthrosis in 5% (1/19) (Table 1). The secondary arthrosis was caused by longstanding corticosteroid treatment for polymyalgia rheumatica. The average age at the time of the revision THA was 69 years (range, 48-82 years). The average time between the primary and revision arthroplasties was 5.2 years (range, 0.4-12.3 years). The femoral implants and fixation method used in the primary operation differed among patients (Table 1). Aseptic loosening was the reason for revision arthroplasty in all patients. Five of these revision arthroplasties were done quite soon (at an average of 2.7 years) after the primary arthroplasty. The loosening of the arthroplasties that failed early was actually caused by cement failure (Boneloc; Polymers Reconstructive, Farum, Denmark). 15 On the Endo-Klinik scale, 6 patients had grade-1 loosening and 13 had grade-2. 2
Calcified Tissue International, 1993
Dual X-ray absorptiometry (DXA) instruments are now able to evaluate bone mineral density (BMD) of bone surrounding metal implants. The assessment of BMD around prosthetic components could provide additional information for the follow-up of total hip arthroplasty (THA). In this study, we evaluated the potential application of DXA in the field of THA. BMD was measured in the proximal femur of both THA and THA-free sides in 14 postmenopausal women 6–18 months after THA. The explored segment was divided into seven zones as proposed by Gruen et al. [18]. The precision error of BMD measurements ranged from 1.8 to 6.8% on the THA side and from 1.1 to 2% to the THA-free side. The reduction of BMD of the THA versus the THA-free side was significant in all seven zones (P
The Journal of Arthroplasty, 1996
To define the precision (reproducibility) of measurement of periprosthetic bone mineral density and bone mineral content, dual-energy x-ray absorptiometry scans were obtained on 45 randomly selected patients who had had a unilateral total hip arthroplasty within the previous 3 years. The coefficients of variation of the bone mineral density in the proximal Gruen zones were 5.0 and 5.3%, corresponding to errors of 0.07 and 0.11 g/cm a. The coefficients of variation of the bone mineral density for the distal zones averaged 2.8%, with an error of 0.08 glcm 2. The coefficients of variation of the bone mineral content were 4.8 and 2.9% for the proximal and distal zones. The contralateral femur was also scanned in 32 of the patients. For the contralateral femur bone mineral density, the coefficients of variation were 5.0% for the proximal zones and 4.8% for the distal zones. The bone mineral content was 6.0% for the contralateral regions. These results imply that differences in bone mineral density greater than 0.16 g/cm 2 (2 standard errors) can be reliably measured. Dualenergy x-ray absorptiometry therefore provides a highly reproducible technique for quantitatively monitoring the changes in bone density that occur after total hip arthroplasty.
The Journal of Arthroplasty, 1996
To define the precision (reproducibility) of measurement of periprosthetic bone mineral density and bone mineral content, dual-energy x-ray absorptiometry scans were obtained on 45 randomly selected patients who had had a unilateral total hip arthroplasty within the previous 3 years. The coefficients of variation of the bone mineral density in the proximal Gruen zones were 5.0 and 5.3%, corresponding to errors of 0.07 and 0.11 g/cm a. The coefficients of variation of the bone mineral density for the distal zones averaged 2.8%, with an error of 0.08 glcm 2. The coefficients of variation of the bone mineral content were 4.8 and 2.9% for the proximal and distal zones. The contralateral femur was also scanned in 32 of the patients. For the contralateral femur bone mineral density, the coefficients of variation were 5.0% for the proximal zones and 4.8% for the distal zones. The bone mineral content was 6.0% for the contralateral regions. These results imply that differences in bone mineral density greater than 0.16 g/cm 2 (2 standard errors) can be reliably measured. Dualenergy x-ray absorptiometry therefore provides a highly reproducible technique for quantitatively monitoring the changes in bone density that occur after total hip arthroplasty.
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2007
Objectives. We used dual energy x-ray absorptiometry (DEXA) and periapical radiography to assess bone density differences after conventional and bone-condensing dental implant techniques. Study design. Single-tooth dental implants were placed by both conventional and bone-condensing techniques in 14 patients with bilateral missing teeth. Dual energy x-ray absorptiometry was used to calculate bone mineral density (BMD) and bone mineral content (BMC) before and 6 and 12 months after implant placement. Furthermore, photodensitometry of periapical radiographs was also assessed. Results. The success rate was 92.9% for the conventional technique and 71.5% for the bone-condensing technique. The BMD was observed to be significantly higher 6 and 12 months after implant placement. The BMC and photodensitometry were significantly increased 6 months after implant placement but showed no further after 12 months. Conclusions. There were no significant differences in BMD, BMC, and photodensitometry between the two implant placement techniques. However, success rate of the conventional technique was greater than the bone-condensing technique, which may be the result of trabecular fracture associated with the bone-condensing.
The Journal of Arthroplasty, 1997
Bone ingrowth into uncemented femoral implants with proximal porous coatings has been designed to avoid proximal stress shielding and preserve femoral strength. Dual-energy x-ray absorptiometry allows repeated quantitative analysis of anteroposterior scans of the proximal femur. By use of dual-energy x-ray absorptiometry and qualitative radiographic changes, 31 total hip arthroplasties with an individually designed, proximally porous-coated prosthesis were evaluated after surgery and at intervals up to 2 years. All implants appeared to achieve successful bone ingrowth and subsequent remodeling. At the most proximal level around the neck osteotomy, the postoperative loss of bone density at 6 months was -14.5%, which persisted at 24 months with -11.6%. At the level of the distal portion of the porous coating in the lower metaphysis, the density change was -8.7%, but bone had remodeled at 24 months with a change in density of only -1.0% compared with the immediate postoperative scan. With a design that results in reliable proximal ingrowth, this study predicts that after an initial decline in bone density, a positive bone remodeling response occurs that could lead to long-term stable fixation of the femoral implant. Key words: dual-energy x-ray absorptiometry, bone remodeling, uncemented femoral implant, proximal porous coating, femur, hip prosthesis.
RELATIONSHIP BETWEEN TOMOGRAPHIC BONE DENSITY AND PRIMARY STABILITY OF OSTEOINTEGRATED IMPLANTS (Atena Editora), 2023
The objective of this study is to correlate the primary stability of implants, given by the insertion torque obtained during installation, to the tomographic bone density measured on cone beam tomography (CBCT), in the same region, considering factors such as age, gender, location, length and diameter of the implants. Data were collected from medical records of 19 patients attended in the specialization course in Implantology at ABO/Petrópolis-RJ, who underwent implant installation surgery between 2011 and 2015. From a total of 114 implants, the insertion torques were obtained, measured by the surgical torquemeter, immediately after insertion into the receptor site. In each patient's CBCT, using the Dental Slice® software, virtual implants were installed in the same positions corresponding to the implants described in the care record. Using the “Hounsfield line” tool present in the program, bone density values were recorded in 3 positions around the implant (buccal, apical and lingual/palatal), in 3 trans-axial sections of the tomography, obtaining an average which was considered the bone density in the region. The results were analyzed using parametric and non-parametric tests, with a significance level of 0.05. Density and torque were greater in the mandible than in the maxilla (p=0.000), and greater in type I and II bones than in type III and IV bones (p=0.000). A moderately significant correlation was found between bone density and implant torque (Spearman correlation coefficient=0.439; p=0.000), suggesting that CBCT can be used to predict insertion torque during surgical planning.
The International journal of oral & maxillofacial implants
To investigate the relationship between bone mineral density (BMD) before implant placement, implant stability measures at implant placement, and marginal bone loss of immediately loaded implants after 1 year in situ. Consecutively recruited patients received Straumann SLActive implants loaded with fixed provisional prostheses within 24 hours. BMD was measured from computed tomographic images before implant placement. Alveolar bone quality was assessed during surgery. Implant stability-both rotational and as measured with resonance frequency analysis-and marginal bone height were assessed at implant placement and after 1 year. The Pearson correlation coefficient was used to calculate correlations, and significance was considered when P < .05. Twenty-one patients received 137 implants (87 in maxillae and 50 in mandibles). BMD was significantly correlated with bone quality classification in both arches (P < .001). Mean BMD was also significantly correlated with stability values ...