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Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_22 | Pages 56 - 56
1 Dec 2016
Parvizi J
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Total hip arthroplasty continues to be one of the most effective procedures. Aseptic loosening compromises the long term outcome of this otherwise successful procedure. Large hemispherical cups may be used during revision surgery for patients with severe bone loss. Acetabular revision with cementless components has been remarkably successful with some series reporting no revisions for aseptic loosening at an average follow-up of 13.9 years. Another study on 186 patients (196 hips) receiving jumbo acetabular components, noted a survivorship of 98% at 4 years and 96% at 16 years. Cementless acetabular revision is now feasible for a wide range of revision situations, including some cases of pelvic discontinuity. The Paprosky classification is useful in predicting the reconstructive technique that will be required. Type I and many Type II defects may be reconstructed with standard cementless components. Many Type II and Type III defects, which involve the loss of additional structural bone, can be reconstructed with a jumbo cup. A jumbo cup is defined by Whaley et al. as a component that is >61 mm in women and >65 mm in men, a definition that is based on a shell that is >10 mm greater than the average diameter cup implanted in women and men. The jumbo cup has the advantage of an increased contact area between host bone and cup which maximises the surface area for ingrowth or ongrowth. The increased area of contact also prevents cup migration by allowing for force dissipation over a large area. Use of a jumbo cup may also decrease the need to use bone graft. In contrast to positioning the cup in the so-called high hip center, a jumbo cup can help to restore the hip center of rotation. The disadvantages of this technique are that host bone may have to be removed to implant the cup, that bone stock is not restored by the reconstruction, and that hemispherical cups have limited applicability in situations of oblong bone stock deficiency. Jumbo acetabular components can be used in combination with both structural and cancellous bone graft. In these cases, the cementless cup must achieve adequate contact with host bone in order to allow bone ingrowth to occur


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_15 | Pages 97 - 97
1 Aug 2017
Lachiewicz P
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Using the Mayo Clinic definition (>62mm in women and >66mm in men), the “jumbo acetabular component” is the most successful method for acetabular revisions now, even in hips with severe bone loss. There are numerous advantages: surface contact is maximised; weight-bearing is distributed over a large area of the pelvis; the need for bone grafting is reduced; and usually, hip center of rotation is restored. The possible disadvantages of jumbo cups include: may not restore bone stock; may ream away posterior column or wall; screw fixation required; the possibility of limited bone ingrowth and late failure; and a high rate of dislocation due to acetabular size:femoral head ratio. The techniques for a successful jumbo revision acetabular component involve: sizing-“reaming” of the acetabulum, careful impaction to achieve a “press-fit”, and multiple screw fixation. We recommend placement of an ischial screw in addition to dome and posterior column screw fixation. Cancellous allograft is used for any cavitary defects. The contra-indications for a jumbo acetabular cup are: pelvic dissociation; inability to get a rim fit; and inability to get screw fixation. If stability cannot be achieved with the jumbo cup alone, then use of augment(s), bulk allograft, or cup-cage construct should be considered. Using titanium fiber-metal mesh components, we reported the 15-year survival of 129 revisions. There was 3% revision for deep infection and only 3% revision for aseptic loosening. There were 13 reoperations for other reasons: wear, lysis, dislocation, femoral loosening, and femoral fracture fixation. The survival was 97.3% at 10 years, but it dropped to 82.8% at 15 years. Late loosening of this fiber metal mesh component is likely related to polyethylene wear and loss of fixation. Dislocation is the most common complication of jumbo acetabular revisions, approximately 10%, and these are multifactorial in etiology and often require revision. Based on our experience, we now recommend use of an acetabular component with an enhanced porous coating (tantalum), highly crosslinked polyethylene, and large femoral heads or dual mobility for all jumbo revisions


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_1 | Pages 62 - 62
1 Feb 2015
Lachiewicz P
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Using the Mayo Clinic definition (>62mm in women and >66mm in men), the “jumbo acetabular component” is the most commonly used method for acetabular revisions now. There are numerous advantages: surface contact is maximised; weight-bearing is distributed over a large area of the pelvis; the need for bone grafting is reduced; and usually, hip center of rotation is restored. The possible disadvantages, or caveats, of jumbo cups include: may not restore bone stock; may ream away posterior column or wall; screw fixation required; the possibility of limited bone ingrowth and late failure; and a high rate of dislocation due to acetabular size:femoral head ratio. The techniques for a successful jumbo revision acetabular component involve: sizing-“reaming” of the acetabulum, careful impaction to achieve a “press-fit”, and multiple screw fixation. We recommend placement of an ischial screw in addition to dome and posterior column screw fixation. Cancellous allograft is used for any cavitary defects. The contraindications for a jumbo acetabular cup are: pelvic dissociation; inability to get a rim fit; inability to get screw fixation; and the presence of <50% living host bone. If stability cannot be achieved with the jumbo cup alone, then use of augment(s), bulk allograft, or cup-cage construct should be considered. Our results with the jumbo acetabular cups in revision arthroplasty have been reported. Using predominantly titanium fiber-metal mesh components, we reported the 15-year survival of 129 revisions. There was 3% revision for deep infection and only 3% revision for aseptic loosening. There were 13 reoperations for other reasons: wear, lysis, dislocation, femoral loosening, and femoral fracture fixation. The survival was 97.3% at 10 years, but it dropped to 82.8% at 15 years. Late loosening of this fiber metal mesh component is likely related to polyethylene wear and loss of fixation. Dislocation is the most common complication of jumbo acetabular revisions, approximately 10%, and these are multifactorial in etiology and often require revision. Based on our experience, we now recommend use of an acetabular component with an enhanced porous coating (tantalum), highly cross-linked polyethylene, and large femoral heads for all jumbo revisions