Migration of the femoral stem after impaction bone grafting. First results of an ongoing, randomised study of the exeter and elite plus femoral stems using radiostereometric analysis.

University Hospital, Rotterdam, The Netherlands.
The Bone & Joint Journal (Impact Factor: 3.31). 09/2002; 84(6):825-31.
Source: PubMed


We report the initial results of an ongoing randomised, prospective study on migration of the Exeter and Elite Plus femoral stems after impaction allografting, as measured by radiostereometry. Clinically, the impaction technique gave good results for both stems. The mean subsidence in the first year was 1.30 mm and 0.20 mm for the Exeter and the Elite Plus stems, respectively. In the second year, the Exeter stem continued to subside further by a mean of 0.42 mm, while the Elite Plus stem did not do so. Subsidence of the Exeter stem correlated with deficiency of bone stock as graded on the Gustilo and Pasternak scale. This correlation was not found for the Elite Plus stem. None of the other parameters which were studied predisposed to subsidence. There was no significant association between the amount of subsidence and the radiological appearance of the graft for either stem. Our findings do not support the theory that radial compression, due to subsidence of the Exeter stem, is the essential stimulus for remodelling in impaction allografting.

Download full-text


Available from: Abida Z Ginai
  • Source
    • "Graft remodeling after the impaction procedure involves a complicated sequence of biological events which have only been partly characterized to date. According to biopsy and retrieval studies (Ullmark and Obrant 2002), minimum bone formation may be initiated 1 month after implantation. After 8–11 months, the osteoid/bone layer might have a thickness of 3–5 mm. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Bone morphogenetic proteins (BMPs) have the potential to improve incorporation of allograft bone in revision surgery. This could result in improved fixation and graft incorporation. We evaluated the effect of mixing OP-1 (BMP-7) with morselized allograft in hip revisions. In a case-control study, 20 acetabular revisions (10 in the study group, 10 controls) and 41 femoral revisions (11 in study group, 30 controls) were done using impaction allografting. The migration of the cups and stems was studied with radiostereometric analysis (RSA) for up to 5 years. Changes of bone mineral density around the femoral component were measured with dual energy X-ray adsorptiometry for 2 years. Bone remodeling and the extent of radiolucent lines were evaluated on conventional radiographs after 5 years. The clinical results were documented using Harris hip score. In the cup study, there was no significant difference in implant migration between the study and control groups. 4 sockets in the study group were classified as radiographically loose after 5 years and 2 of them were revised after 5 years. After 2 years, the stems in the study group showed slightly increased posterior tilt (0.3 degrees , p = 0.03). 1 stem in the study group loosened and was revised during the third year of observation. The sample size and study design in our evaluation did not allow any firm conclusions. Absence of any trend to improved fixation and early revisions in the study group prompted us to stop recruitment to this study.
    Full-text · Article · Mar 2006 · Acta Orthopaedica
  • Source
    • "The method is based on implantation of tantalum bead landmarks. Stereoradiographs are then used to determine the location of the markers three-dimensionally, allowing calculation of translations and rotations between different segments [22] [25] [29]. For example, in clinical fracture research, the method has been applied in evaluation of the mechanical stability of femoral neck fractures augmented with resorbable cement [20]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of the current study was to verify the feasibility of radiostereometric analysis (RSA) in monitoring three-dimensional fracture micromotion in fractures of the distal radius. The experimental set-up consisted of a simulated model of an extra-articular Colles' fracture, including metallic beads inserted into the bone on either side of the fracture site. The model was rigidly fixed to high precision micrometer stages allowing controlled translation in three axes and rotation about the longitudinal and transverse axes. The whole construct was placed inside a RSA calibration cage with two perpendicular radiographic film cassettes. Accuracy was calculated as the 95% prediction intervals from the regression analyses between the micromotion measured by RSA and actual displacements measured by micrometers. Precision was determined as the standard deviation of five repeated measurements of a 200 microm displacement or a 0.5 degrees rotation along a specific axis. Translations from 25 microm to 5mm were measured with an accuracy of +/-6 microm and translations of 200 microm were measured with a precision of 2-6 microm. Rotations ranging from 1/6 degrees to 2 degrees were measured with an accuracy of +/-0.073 degrees and rotations of 1/2 degrees were measured with a precision of 0.025 degrees -0.096 degrees . The number of markers and their configuration had greater impact on the accuracy and precision of rotation than on those of translation. Aside from the unknown rate of clinical marker loosening, the current results favor the use of at least four markers in each bone fragment in distal radius fractures. These results suggest a strong rationale for the use of RSA as an objective tool for comparing different treatment modalities and novel bone graft substitutes aimed at stabilization of fractures of the distal radius.
    Full-text · Article · Apr 2005 · Journal of Orthopaedic Research
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report here the study of a personal series of 129 consecutive femoral impaction grafting during hip revision replacement performed between January 1991 and December 2005. The indication for the revision of the femoral component was aseptic loosening in 127 hips and septic loosening in two. The precise locations of the segmental defects and osteolytic areas were determined and classified, with use of the Endo-Klinik System, as follows: grade 2 in 75 hips, grade 3 in 43, and grade 4 in 11. Removal of the components, debris and cement was done with special care to achieve a complete resection of fibrous tissue in the medullary canal to ensure a direct contact between the graft and the host bone. Before impaction grafting, femoral segmental bone defects or windows were reconstructed and reinforced with strut allograft and cerclage wires. We used in all hips a special revision set of instruments specially designed for impaction grafting. All the acetabular cups were also revised. Clinical and radiologic evaluation was performed at six weeks, three months, six months and one year. Then, patients were reviewed every year for the first five postoperative years and every two years thereafter. A survivorship analysis was performed to determine the overall success of the procedure. Failure was defined as an implant that had been revised or that was radiologically loosened at the time of follow-up. The survival curve was derived from the cumulative survival rate over time, as calculated from the actuarial life table. At the last follow-up evaluation, seven patients (seven hips) had died and two (two hips) were lost to follow-up. The follow-up of these nine patients ranged from two to ten years. One hundred and twenty patients (120 hips) were reviewed with a mean follow-up of 8.2 years (range, two to 16 years). The average follow-up of the whole series was 8.4 years (range, two to 16 years). At the time of the final review 1 of the 129 hips had migration of the stem’s cement mantle relative to the bone (5 mm) with lucent lines at the graft-host interface in three Gruen zones. Another one had migration within the cement (8 mm) with lucent line at the distal graft-host interface and a distal fracture of the cement mantle. These two stems were considered as definitely loosed according to the criteria of Johnston et al. but none of them was revised. The remaining 127 hips showed no radiological changes at the latest examination concerning stem migration and radiolucent lines. One acetabular definite loosening occurred at ten years and was revised at 11 years postoperatively. In this respect, of the 129 hips, only one hip was revised at 11 years’ follow-up (0.7%). The survivorship analysis, with radiologic loosening as the endpoint, yielded a 98% cumulative survival rate for the femoral component and for the acetabular component, 99% at eleven years follow-up. The survival rate with revision for any reason as the endpoint was 99.4% at eleven years follow-up. The results observed in this series, regarding the need for a repeat revision for any reason, are in agreement with the excellent outcome reported by other authors using similar technique. Nevertheless two main differences must be emphasized when comparing the results of this study with the others. The first one is the low rate of subsidence and the second is the absence of postoperative femoral fracture. The quality of bone grafting and the use of a Kerboull stem, double tapered and polish, were associated with the very low rate of distal migration. The unconditional reconstruction of distal bone deficiency or weakness with bone graft strut appeared efficient to prevent the occurrence of femoral fracture, despite the unique use or standard stems.
    No preview · Article · Jun 2008 · Interactive Surgery
Show more