Acetabular Reinforcement Device Research Articles

Morsellized Allograft and Acetabular Reconstruction Cage: Follow-up of 2 to 9 years

We report the outcome of 32 patients who underwent total hip replacement (THR) augmented with morsellized fresh frozen femoral head allografts and acetabular reconstruction cages. Nine patients underwent primary THR and 23 patients underwent revision THR. Follow-up ranged from two to 9 years. Two most common indications for the procedures as reported in literature were rheumatoid arthritis and aseptic loosening of the hip. All but one patient achieved good outcome with radiographs showing full incorporation of bone grafts and no evidence of loosening of the implants. Morsellized bone grafting used with acetabular reinforcement devices is valuable for addressing severe acetabular deficiencies.

Revision total hip replacement using the Kerboull acetabular reinforcement device with morsellised or bulk graft

We retrospectively evaluated 42 hips which had undergone acetabular reconstruction using the Kerboull acetabular reinforcement device between September 1994 and December 1998. We used autogenous bone chips from the ilium and ceramic particle morsellised grafts, even in large acetabular bone defects, in the early stages of the study. Thereafter, femoral head allograft was used as bulk graft in patients with large acetabular defects. Ceramic blocks and the patients' contralateral femoral head were also used as bulk graft. The mean follow-up period was 8.7 years (4.3 to 12). Survivorship analysis was performed using radiological failure of the acetabular component, irrespective of whether it was revised, or not, as the end-point. The survival rate of the morsellised graft group (25 hips) and the bulk graft group (17 hips) at ten years was 53% (95% confidence interval (CI) 42.5% to 63.5%) and 82% (95% CI 72.4% to 91.6%), respectively. The mid-term results of revision total hip replacement with the Kerboull device were better when bulk graft was used in any size of bone defect.

Impaction allografting and the Kerboull acetabular reinforcement device

Background The incidence of acetabular loosening with segmental and cavitatory bone loss increases as the number of total hips implanted increases. Revisionhip arthroplasty using impacted bone graft and an acetabular reinforcement device is one solution to this problem.Patients and methodsClinically and radiographically, we assessed 35 hips in 33 patients who had undergone revision hip arthroplasty using impaction grafting and the Kerboull acetabular reinforcement device. Mean follow-up was 5 (3–7) years.Results The mean Mayo score preoperatively was 30, which improved to a mean score of 85. Good to excellent clinical results were seen in 25 patients. The 8 individuals scoring below 80 had significantly more comorbid conditions than the others. No acetabular reconstruction required re-revision. Aseptic loosening occurred in 6 patients. Graft resorption occurred in 5 cases, resulting in inferior hook fracture of the Kerboull device. This was noted at a mean of 13 months after surgery. Further follow-up showed this to be non-progressive, with incorporation of the remaining graft to the host bone. These patients all had good to excellent Mayo hip scores.Interpretation Early results of revision acetabular surgery using impaction grafting and the Kerboull shell in patients with severe osteolysis have shown good functional outcome. However, 6 of 35 patients had radio-graphic evidence of aseptic loosening without progression for 4 years. Long-term follow-up is required to ensure that this loosening does not result in failure.

Reinforcement rings with hook in acetabular reconstruction

Acetabular osteolysis associated with socket loosening is one of the main long-term complications of total hip arthroplasty. In the case of major bone loss where less than 50% host bone coverage can be obtained with a porous-coated cementless cup, it is generally agreed that a metal ring in association with a cemented component and allograft bone should be used. Herein we describe the technical details of the use of the Kerboull acetabular reinforcement device and the GAP cup. Both these devices have a hook that has to be placed under the teardrop of the acetabulum and a plate for iliac fixation. The main advantages of these devices are their help in restoring the normal hip center of rotation, guiding the reconstruction, and partially unloading the graft. The Kerboull acetabular reinforcement device has provided a 92% survival rate free of loosening at 13-year follow-up in a consecutive series of 60 type III and IV deficiencies.

Acetabular reconstruction using a Kerboull-type acetabular reinforcement device and hydroxyapatite granules: A 3- to 8-year follow-up study

Between 1993 and 1997, 21 consecutive revision total hip arthroplasties were performed in 20 patients using hydroxyapatite (HA) granules supported by a Kerboull-type reinforcement acetabular device. Acetabular bone loss according to the American Academy of Orthopaedic Surgeons (AAOS) system was type II for 5 hips and type III for 16 hips. Autografts were used to reconstruct the major segmental defects in 6 hips. The mean follow-up period of the series was 5 years and 4 months. No migration of the socket was seen. Slight inclination of the acetabular device was noted in 1 hip without functional deficits. The mean preoperative Merle d’Aubigné hip functional score was 9.3 versus 15.4 at the latest follow-up evaluation. Acetabular reconstruction with HA granules and a Kerboull-type acetabular device provided satisfactory 3- to 8-year clinical and radiographic results.

Acetabular revision using pelvic reinforcement devices

Addressing deficient acetabular bone stock is one of the most challenging aspects of revision total hip arthroplasty. Many different techniques have been described to restore acetabular bone stock and achieve stable cup fixation. Previous reports on the short- and medium-term results of acetabular revision with cages and rings for large defects have been promising. More recently, long-term clinical and radiographic follow-up data have been published. These data are also encouraging with regard to implant survival and patient satisfaction. Controversy remains as to when these devices should be used and which design is best indicated for specific patterns of acetabular bone deficiency. The most ideal types of bone graft used to reconstruct the acetabulum remains controversial as well. Despite these controversies, it appears that acetabular reinforcement devices are valuable for addressing severe acetabular deficiencies.

Histological evaluation of allograft bone after acetabular revision arthroplasty: report of two cases

We recently had the opportunity to take histological sections from two patients who underwent acetabular reconstruction in which allograft and ME Müller acetabular roof reinforcement rings were used. In one patient (case 1), histological sections of the chipped allograft were taken on two separate occasions from the same area, at 7 months, and at 3 years and 11 months after the bone graft. The histology of the chipped allograft showed necrosis at 7 months, but almost normal morphology of trabecular bone formation at 3 years and 11 months after the bone graft. In the other patient (case 2) histological sections of the block allograft and chipped allograft were taken at 1 year and 8 months after the bone graft. The block allograft showed only a small amount of admixture of newly formed bone with the necrotic bone, while the chipped allograft showed a large amount of newly formed bone, with only a small amount of necrotic bone remaining. Therefore, we principally use chipped allograft for acetabular reconstruction, in order to achieve early and complete graft incorporation. If a block allograft is used in a weight-bearing area, it should be protected from excessive load by using an acetabular reinforcement device.

The management of severe acetabular bone loss using structural allograft and acetabular reinforcement devices

The cases of 37 acetabular reconstructions in 35 patients with major structural pelvic bone loss were reviewed. At an average follow-up of 7.1 years, patients rated their results as excellent in 12 cases (32.4%), good in 22 (59.5%), fair in 2 (5.4%), and poor in 1 (2.7%). Thirty-four cases (91.9%) were classified as a clinical success. Thirty-six allografts (97.3%) had radiographic evidence of full incorporation. Of the unrevised hips, 1 (2.7%) was classified as definitely loose, 2 (5.4%) as probably loose, and 4 (10.8%) as possibly loose. One revision of an acetabular component was required because of late sepsis. This is the first reported series on the use of acetabular reinforcement devices with solid bulk allograft covering more than 50% of the socket. The allograft is protected in the early postoperative period, superior migration of the cup is virtually eliminated as a complication, and the incidence of aseptic loosening is greatly diminished.

Experimental study of periacetabular deformations before and after implantation of HIP prostheses

This work is based upon an experimental simulation of one-legged stance, under loads close to the average body weight. Skeletons, harvested from fresh non-embalmed cadavers, included pelvis, two lumbar vertebrae, and both femurs. Periacetabular deformations were studied using tridirectional strain gauges before and after implantation of different types of acetabular prostheses in eight pelves: conventional polyethylene-cemented sockets, polyethylene sockets cemented into a metallic device, metal-backed cemented sockets, and hemispherical cementless press-fit cups with porous or hydroxyapatite coating. Strain measurements showed the persistence of important bone deformations at implant periphery. Mean values of normal periacetabular deformations were significantly reduced in two out of five acetabula implanted with cemented implants. In contrast, mean values of normal and circumferential deformations increased when polyethylene sockets were cemented into acetabular reinforcement devices, but this augmentation was significant in only one out of two cases. After implantation of cementless hemispherical metal-backed cups, periacetabular bone deformations also increased, but modifications were significant in a single case. Results are discussed according to the type of fixation (cemented or cementless), and to the difference in rigidity between implant and bone. There was no clear relation between implant stiffness and the magnitude of bone deformations.