Introduction. Impaction bone grafting (IBG) is a reliable technique for acetabular revision surgery with large segmental defects. However, bone graft resorption and cup migration are some of the limitations of this tecnique. We assess frequency and outcome of these complications in a large acetabular IBG series. Patients and Methods. We analysed 330 consecutive hips that received acetabular IBG and a cemented cup in revision surgery with large bone defects (Paprosky types 3A and 3B). Fresh-frozen femoral head allograft was morselized manually. The mean follow-up was 17 years (3–26). All data were prospectively collected. Kaplan-Meier survivorship analysis was performed. Changes in different paremeters regarding cup position were assessed pre- and postoperatively and at the follow- up controls. Only variations greater than 5º and 3 mm were considered. Results. The mean Harris Hip Score improved from 48.3+8.5 to 84.6+12.8 at final follow-up. The radiological analysis showed cup migration in 42 hips. The mean appearance time was 4.3 years (range, 1–25). Migration was progressive and painful in 27 hips (67.5%) requiring cup revision. Lateral mesh was more frequently associated with migrated cups (p=0.034). Cup tilt was found in 37 out 42 migrated cups, however cranial migration was more frequent in progressive migrated cups (p=0.02). There were 34 re-revisions, 27 due to aseptic cup loosening, 6 due to dislocation and one due to infection. The survival rate for any cause at 16 years was 81.2% (95% Confidence Interval (CI): 74.0 to 88.4) and for aseptic cup loosening was 83.4% (95% CI: 76.2–90.6). In all surviving hips trabecular incorporation was observed without radiolucent lines. Conclusions. IBG continues to be a reliable technique for large defects in acetabular revision surgery. Bone graft resorption and cup migration was not frequent in this large series and one-third of cases were not progressive. Cup migration was more frequent in cases with a segmental roof defect in which a lateral mesh was used

Femoral revision after cemented total hip arthroplasty (THA) might include technical difficulties, following essential cement removal, which might lead to further loss of bone and consequently inadequate fixation of the subsequent revision stem. Bone loss may occur because of implant loosening or polyethylene wear, and should be addressed at time of revision surgery. Stem revision can be performed with modular cementless reconstruction stems involving the diaphysis for fixation, or alternatively with restoration of the bone stock of the proximal femur with the use of allografts. Impaction bone grafting (IBG) has been widely used in revision surgery for the acetabulum, and subsequently for the femur in Paprosky defects Type 1 or 2. In combination with a regular length cemented stem, impaction grafting allows for restoration of femoral bone stock through incorporation and remodeling of the proximal femur. Cavitary bone defects affecting the metaphysis and partly the diaphysis leading to a wide femoral canal are ideal indications for this technique. In case of combined segmental-cavitary defects a metal mesh is used to contain the defect which is then filled and impacted with bone grafts. Cancellous allograft bone chips of 2 to 4 mm size are used, and tapered into the canal with rods of increasing diameters. To impact the bone chips into the femoral canal a dummy of the dimensions of the definitive cemented stem is inserted and tapped into the femur to ensure that the chips are firmly impacted. Finally, a standard stem is implanted into the newly created medullary canal using bone cement. To date several studies from Europe have shown favorable results with this technique, with some excellent long-term results reported. Advantages of IBG include the restoration of the bone stock in the proximal femur, the use of standard length cemented stems and preserving the diaphysis for re-revision. As disadvantages of the technique: longer surgical time, increased blood loss and the necessity of a bone bank can be mentioned

Background. Impaction bone grafting (IBG) using a circumferential metal mesh is one of the options that allow restoration of the femoral bone stock and stability of the implant in hip arthroplasty. Here we examined the clinical and radiographic outcome of this procedure with a cemented stem and analyzed experimentally the initial stability of mesh–grafted bone–cemented stem complexes. Methods. We retrospectively reviewed 6 hips (6 patients) that had undergone femoral revisions with a circumferential metal mesh, impacted bone allografts, and a cemented stem. The mean follow-up period was 2.9 years (range, 1.4–3.8 years). Hip joint function was evaluated with the Japanese Orthopaedic Association hip score, and radiographic changes were determined from radiographs. The initial resistance of cemented stem complexes to axial and rotational force was measured in a composite bone model with various segmental losses of the proximal femur. Results. The hip score improved from 50 (range, 10–84) preoperatively to a mean of 74 (range, 67–88) at the final follow-up. The overall implant survival rate was 100% at 4 years when radiological loosening or revision for any reason was used as the endpoint. No stem subsided more than 3 mm vertically within 1 year after implantation. Computed tomography showed reconstitution of the femoral canal in a metal mesh. In mechanical analyses, there was no influence on the stem stability to axial compression during the repeated axial compression test between IBG reconstruction rates. On the other hand, for IBG reconstruction rate of 66.7%, grafted bone-Sawbone juntion was buckled under the axial breaking force. In contrast, under rotational load, the rotation angles of the stainless mesh were strongly affected by the IBG reconstruction rate. Conclusions. The short-term results show good outcomes for reconstruction of proximal bone loss with impaction bone allografts and a circumferential mesh. The procedure should be applied in cases where the circumferential proximal bone loss is less than half of the stem length implanted

Introduction. Impaction bone grafting for reconstitution of acetabular bone stock in revision hip surgery has been used for nearly 30 years. We report results in a group of patients upon whom data has been collected prospectively with a minimum ten year follow-up. Material and Methods. Acetabular impaction grafting was performed in 305 hips in 293 patients revised for aseptic loosening between 1995 and 2001. In this series 33% of cases required stainless steel meshes to reconstruct medial wall or rim defects prior to graft impaction. These meshes were the the only implants used for this purpose in this series. All Paprosky grades of defect were included. Clinical and radiographic outcomes were collected in surviving patients at a minimum of 10 years following the index operation; mean follow-up was 12.4 years (SD 1.5; range 10.0–16.0). Results. Kaplan-Meier survivorship with revision for aseptic loosening as the endpoint was 86% (95% CI 81.1 to 90.9%). Clinical scores for pain relief and function remained satisfactory (mean OHS 33.3, Harris hip score for pain 36.7, Harris hip score for function 27.3). Of the 125 hips still available with at least 10 years of radiographic follow-up, 97 appeared stable and 28 were judged to be radiologically loose; however, there was no significant difference in the pain and function scores between the two groups. The overall complication rate was 11.5%, including 1% peri-operative death, 3.3% dislocation and 0.3% deep infection. Discussion. This is the largest series of medium- to long-term results of acetabular impaction bone grafting with a cemented cup for revision hip arthroplasty reported to date. The technique is particularly successful when used for Paprosky grade 1 and 2 deficiencies; grade 3 deficiencies may be better managed with a different method for reconstructing larger defects e.g. trabecular metal augments. Conclusion. This series shows good long-term results for impaction bone grafting of acetabular deficiencies in revision hip surgery, with survivorship of 86% for aseptic loosening at 13.5 years and satisfactory clinical outcomes

Aims. Impaction bone grafting with milled human allograft is the gold standard for replacing lost bone stock during revision hip surgery. Problems surrounding the use of allograft include cost, availability, disease transmission and stem subsidence (usually due to shear failure of the surrounding allograft). The aim of this study was to investigate various polymers for use as substitute allograft. The ideal graft would be a composite with similar mechanical characteristics as allograft, and with the ability to form de novo bone. Methods. High and low molecular weight (MW) forms of three different polymers (polylactic acid (PLA), poly (lactic co-glycolic) acid (PLGA) and polycaprolactone (PCL)) were milled, impacted into discs, and then tested in a custom built shear testing rig, and compared to allograft. A second stage of the experiment involved the addition of skeletal stem cells (SSC) to each of the milled polymers, impaction, 8 days incubation, and then tests for cell viability and number, via fluorostaining and biochemical (WST-1) assays. Results. The shear strengths of both high/low MW PLA, and high/low MW PLGA were significantly higher than those of milled allograft (P< 0.001, P< 0.001, P< 0.005 and P< 0.005) but high and low MW PCL was poor to impact, and had significantly lower shear strengths (P< 0.005, P< 0.001). Fluorostaining showed good cell survival on high MW PLA, high MW PCL and high MW PLGA. These findings were confirmed with WST-1 assays. Conclusions. High MW PLA as well as high MW PLGA performed well both in mechanical testing and cell compatibility studies. These two polymers are good contenders to produce a living composite for use as substitute human allograft in impaction bone grafting, and are currently being optimised for this use via the investigation of different production techniques and in-vivo studies

Introduction. Loss of bone stock is a technically challenging problem in revision total hip arthroplasty (RevisionTHA). Impaction bone grafting (IBG) is an attractive biological method of reconstruction. We performed acetabular revisions using IBG and cemented cup in patients with failed hip prosthesis and large defects. The purpose is to report the short term results of revision THA with using IBG. Patients & Methods. We retrospectively reviewed 19 patients/19 hips revised for aseptic loosening of a cemented or uncemented cup, three male/16 female, mean 65.5 ± 8.8 years old (43–75). Mean follow up time is 18 months. Classification of acetabular defects according to A.A.O.S classification were Type I; 5 hips, Type III; 13 hips and Type V; 1 hip. Before impacting the morselized bone allograft and cement, segmental acetabular defects were reconstructed with metallic meshes screwed to the bone bed. Morselized allograft bone chips (diameter 7ï¼ 10 mm) were impacted forcefully. All-polyethylene cups (Stryker, Crossfire) were cemented. Clinical examination was performed using Japanese Orthopaedic Association (JOA) score. Radiographic examination was performed using AP radiographs. We measured the inclination cup angle, the distance of superior migration, the presence of loosening of the implanted cup, 4 weeks postoperatively and at the last follow up. Loosening was defined as migration distance was more than 5 mm in any direction. Results. Clinical JOA score improved from 61.0±3.9 to 83.6±2.7 at the last follow up. Complication in this study included one sciatic nerve palsy and one dislocation. In the radiographical analysis, inclination angle changed 41.8 ±2.2° at 4 weeks postoperatively to 42.3±1.8° at the last follow up. The average superior migration was 1.65±0.62 mm (0–9.00), and one loosening case (9.0 mm) was founded. In the loosening case, preoperative radiograph showed the shell had penetrated into the acetabulum. The case had extensive bone defect (4 cm×4 cm) including the medial wall and anterior column. Summary. The short term result of revision THA with using IBG was reported and most cases showed excellent clinical and radiographic results. But one loosening case was founded. The limitation of IBG may be associated with the lacked bony support behind the graft

Impaction bone grafting (IBG) of the acetabulum in cemented primary total hip replacement is a useful technique in the management of acetabular deficiencies. It has the capacity to restore anatomy and bone stock with good long-term outcome. We present 125 consecutive cases of IBG with a cemented polyethylene component. All patients who received full IBG of the acetabulum in primary cemented Exeter total hip replacements and who underwent surgery between August 1995 and August 2003 were identified. All operative and follow-up data was collected prospectively and no patients were lost to follow-up. All patients underwent pre-operative and regular post-operative hip scores with the Harris, Oxford and the modified Charnley scoring systems. Data on indication, surgical technique, socket position and migration and revision was reviewed at a mean follow-up of 7.6 (range 5 to13.4) years. Between August 1995 and August 2003, 113 patients (85 females) with an average age of 67.8 (range 22.9–99.2) years underwent 125 primary Exeter cemented total hip replacements with IBG of acetabular defects. Acetabular defects were classified according to the AAOS classification as cavitatory in 62 hips and as segmental, requiring application of a rim mesh prior to IBG, in 63 hips. Life tables were constructed demonstrating 86.4% survival of the acetabular component at 13.4 years with revision for any reason as the endpoint and 89.3% survival with revision for aseptic loosening as the endpoint. Of the seven patients who underwent revision for aseptic loosening, all had pre-operative segmental acetabular defects requiring application of a rim mesh. No patient who underwent IBG for a cavitatory defect required revision surgery for aseptic loosening. Survival of the Exeter cemented femoral component was 100% at 13.4 years with revision for aseptic loosening as the endpoint. There were 11 radiographic failures of the acetabular component, which have not been revised at latest review. One of these is symptomatic but not fit for revision surgery, two were asymptomatic at time of death and eight are asymptomatic but under review. This is the largest series of IBG in the acetabulum in cemented primary THR. Our results suggest that the medium term survival of this technique is good, particularly when used for cavitatory defects. Although there were radiographic failures, these are largely asymptomatic and may not require revision