JBJS | Extra-Large Uncemented Hemispherical Acetabular Components for Revision Total Hip Arthroplasty

The Journal of Bone & Joint Surgery, Volume 83, Issue 9

Scientific Articles | September 01, 2001

Extra-Large Uncemented Hemispherical Acetabular Components for Revision Total Hip Arthroplasty

Andrew L. Whaley, MD; Daniel J. Berry, MD; W. Scott Harmsen, MS

Investigation performed at the Department of Orthopedics, Mayo Clinic, Rochester, Minnesota
Andrew L. Whaley, MD
Daniel J. Berry, MD
W. Scott Harmsen, MS
Department of Orthopedics, Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for D.J. Berry: berry.daniel@mayo.edu

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study.

The Journal of Bone & Joint Surgery. 2001; 83:1352-1357

5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case

Article

Figures

References

text A A A

Abstract

Background: Extra-large uncemented components provide several advantages for acetabular revision, but limited information is available on the results of their use. The purpose of this study was to evaluate, at a minimum of five years, the results associated with the use of an extra-large uncemented porous-coated component for acetabular revision in the presence of bone loss.

Methods: Eighty-nine extra-large uncemented hemispherical acetabular components were used for revision after aseptic failure of a total hip arthroplasty in forty-six men and forty-three women (mean age at revision, fifty-nine years; range, thirty to eighty-three years). The revision implant (a Harris-Galante-I or II cup fixed with screws) had an outside diameter of 66 mm in men and 62 mm in women. Seventy-nine patients had a segmental or combined segmental and cavitary acetabular bone deficiency before the revision. Particulate bone graft was used in fifty-four hips and bulk bone graft, in nine.

Results: One patient died with the acetabular component intact and two patients were lost to follow-up within five years after the operation. At the time of the last follow-up, four acetabular components had been removed or revised again (two for aseptic loosening). All of the remaining patients were followed clinically for at least five years (mean, 7.2 years; range, 5.0 to 11.3 years). In the hips that were not revised again, only two sockets had definite radiographic evidence of loosening. All four of the sockets that loosened were in hips that had had combined cavitary and segmental bone loss preoperatively. In the hips that were not revised again, the mean modified Harris hip score increased from 56 points preoperatively to 83 points at the time of the most recent follow-up. The most frequent complication, dislocation of the hip, occurred in eleven patients. The probability of survival of the acetabular component at eight years was 93% (95% confidence interval, 85% to 100%) with removal for any reason as the end point, 98% (95% confidence interval, 92% to 100%) with revision for aseptic loosening as the end point, and 95% (95% confidence interval, 88% to 100%) with radiographic evidence of loosening or revision for aseptic loosening as the end point.

Conclusions: This study demonstrates that extra-large uncemented components used for acetabular revision in the presence of bone loss perform very well and have a low rate of aseptic loosening at the time of intermediate-term follow-up.

Figures in this Article

Introduction

Introduction | Materials and Methods | Results | Discussion | References

Several authors have reported excellent intermediate-term results in association with the use of an uncemented socket for acetabular revision^1-4. An uncemented socket normally can be used for acetabular revision, even in the presence of acetabular bone loss, but modifications in technique usually are required. The main acetabular reconstruction techniques include (1) placement of an acetabular component on host bone in a superior position (a high hip center), (2) placement of an acetabular component in combination with structural bone grafts, and (3) placement of an extra-large acetabular component. Extra-large sockets provide several advantages over standard-sized implants in the revision setting⁵. First, they maximize surface contact between the porous-coated prosthesis and the host bone and increase the area of the pelvis over which forces are dissipated. Second, extra-large implants fill many bone defects, thereby reducing the need for bone-grafting. Finally, extra-large sockets tend to normalize the center of rotation of the hip, which may restore soft-tissue tension and reduce impingement between the femur and the pelvis. To date, only a few reconstructions with extra-large uncemented sockets have been reported^5-7. The purpose of this study was to evaluate, at a minimum of five years, the results associated with the use of an extra-large uncemented porous-coated socket for acetabular revision in the presence of bone loss.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-A:: Pre-revision anteroposterior radiograph of the left hip of a fifty-eight-year-old man who had a failed total hip arthroplasty due to aseptic loosening of the acetabular component.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-B:: Anteroposterior radiograph of the same patient made six years after revision of the acetabular component with an extra-large uncemented hemispherical socket. The component was well fixed.

Materials and Methods

Introduction | Materials and Methods | Results | Discussion | References

We identified all revision total hip arthroplasties that had been performed at our institution before 1993, for reasons other than infection, in which the acetabulum was reconstructed with a Harris-Galante-I or II component (Zimmer, Warsaw, Indiana) implanted without bone cement. Both designs are made of titanium, are coated with titanium wire mesh, and have a modular polyethylene liner. Both types of cups have multiple screw-holes; 5.1-mm screws are used for the Harris-Galante-I component, and 6.5-mm screws are used for the Harris-Galante-II component. For the purposes of this study, we reviewed only reconstructions that had been performed with extra-large uncemented sockets. Extra-large sockets were defined as having a minimum outside diameter of 66 mm for men and 62 mm for women. This definition was based on the fact that these sizes were 10 mm greater than the mean implant diameters (56.9 mm for men and 51.9 mm for women) used for primary total hip arthroplasties performed with the same socket designs at our institution during the same period. To ensure that the selection criteria did not simply select for patients with a large pelvis, another screen was added to the inclusion parameters. The outside diameter of the socket that had been used for primary total hip arthroplasty had to have been no greater than 56 mm for men and 52 mm for women. When the size of the acetabular component that had been used for primary total hip arthroplasty was not known, the native acetabulum of the contralateral hip was templated for an uncemented socket, the size of which had to be no greater than 56 mm for men and 52 mm for women.

Eighty-nine hips in eighty-nine patients met the criteria for inclusion in this study. A total of 630 Harris-Galante-I or II prostheses (308 in men and 322 in women) were implanted during revision total hip arthroplasties at our institution during this time-period; thus, extra-large sockets were used in 14% of the revisions involving these designs. The study included forty-seven right and forty-two left hips in forty-six men and forty-three women. The mean age of the patients at the time of the revision was fifty-nine years (range, thirty to eighty-three years). Twenty Harris-Galante-I and sixty-nine Harris-Galante-II prostheses were implanted. The cup sizes ranged from 62 to 70 mm for women and from 66 to 80 mm for men. The femoral head size was 32 mm in twenty-five hips, 28 mm in fifty-three hips, 26 mm in one hip, and 22 mm in ten hips.

The indication for revision was aseptic acetabular loosening in thirty-eight patients (43%), aseptic acetabular and femoral loosening in forty-two (47%), and aseptic acetabular loosening with femoral periprosthetic fracture in five (6%); the remaining four (4%) had other indications. In fifty-eight hips, the femoral component was also revised at the time of the revision. The patients had had a median of two previous arthroplasties (range, one to five arthroplasties) of the ipsilateral hip.

The revision was performed through an anterolateral approach in sixty patients, a posterolateral approach in seventeen, and a transtrochanteric approach in twelve. All of the acetabular components were fixed with screws. The acetabulum was reamed in the so-called line-to-line fashion or was underreamed by 1 to 2 mm prior to implant insertion. Particulate bone graft was used in fifty-four patients, and bulk bone graft was used in nine.

All patients were followed prospectively and were queried concerning the status of the hip either in person or with use of a standardized letter or telephone questionnaire at one, two, five, and ten years after the procedure (or more often). Radiographs of the involved hips were made at each visit; patients who were unable to return to our institution were asked to have radiographs made locally and then sent to us. Their clinical status was assessed before and after the arthroplasty with the modified Harris hip score⁸.

Definite acetabular loosening was defined as acetabular migration of 2 mm in either the horizontal or the vertical direction, rotation of the implant, screw breakage, or a radiolucent line of >1 mm in all zones⁹. Migration of the acetabular component and the preoperative and postoperative centers of hip rotation were estimated by measuring the position of the implant with respect to fixed pelvic landmarks (the interteardrop line and the teardrop) on immediate postoperative and subsequent radiographs¹⁰. Radiolucent lines at the prosthesis-bone interface were recorded with use of the three zones described by DeLee and Charnley¹¹. Stability of the femoral component was assessed according to the method of Engh et al.¹² for uncemented implants and according to the method of Harris et al.¹³ for cemented implants.

Pre-revision acetabular bone deficiencies were classified retrospectively on radiographs. According to the system of the American Academy of Orthopaedic Surgeons¹⁴, the deficiency was categorized as segmental in three hips, as cavitary in ten, as combined segmental and cavitary in seventy-six, and as pelvic discontinuity in none. According to the method of Paprosky et al.², the deficiency was categorized as type-I in six hips, type-IIa in eleven, type IIb in twenty-six, type IIc in seventeen, type IIIa in twenty-five, and type IIIb in four.

Survivorship analysis was performed with the Kaplan-Meier method¹⁵.

Results

Introduction | Materials and Methods | Results | Discussion | References

One patient died with the acetabular implant intact within five years after the operation. Two patients had revision of the femoral component elsewhere (both at 2.4 years postoperatively) and were subsequently lost to follow-up. Four patients had removal or repeat revision of the acetabular component (at 4.8, 5.1, 5.9, and 7.8 years postoperatively). The remaining eighty-two patients were followed clinically for a mean of 7.2 years (range, 5.0 to 11.3 years) and radiographically for a mean of 6.2 years (range, 5.0 to 11.3 years) (Figs. 1-A and 1-B).

Repeat Revisions

Four of the eighty-nine metal acetabular shells were removed or were revised again. The indications for removal or repeat revision were aseptic loosening in two patients (one of whom had had therapeutic pelvic irradiation), infection in one patient, and dislocation in one patient (in whom the acetabular component was well fixed). One patient with a well-fixed socket had an exchange of the polyethylene liner because of recurrent dislocations. Six other patients subsequently had an exchange of the polyethylene liner during a femoral revision. None of the liners were exchanged because of severe wear or a problem with the locking mechanism. Four other patients had revision of the femoral component with retention of the acetabular shell and the polyethylene liner.

Clinical Results

The mean modified Harris hip score increased from 56 points preoperatively to 83 points at the time of the most recent follow-up for patients who did not have a subsequent revision and were followed for at least five years (p < 0.0001). Before the index revision, seventy-four (83%) of the original eighty-nine patients had moderate or severe pain. At the time of the last follow-up, thirty-eight of the remaining eighty-two patients had no pain, twenty-four had mild pain, seventeen had moderate pain, and three had severe pain. Seven of the twenty patients with moderate or severe pain had definite radiographic evidence of femoral loosening.

Radiographic Results

Before revision the hip center was a mean of 40 mm (range, 17 to 67 mm) proximal to the interteardrop line, and after revision it was a mean of 33 mm (range, 10 to 58 mm) proximal to the interteardrop line. Before revision the center of hip rotation was a mean of 39 mm lateral to the medial aspect of the teardrop, and after revision it was a mean of 43 mm lateral to the same landmark. In seventy hips the center of rotation was more lateral after revision, and in ten hips it was at the same position or was <3 mm medial to the pre-revision location. In nine hips the center of rotation was >3 mm medial to the pre-revision location, but in each of these hips the pre-revision hip center had been >40 mm lateral to the teardrop because the failed socket had migrated superiorly and laterally or had been implanted too laterally.

Sixty-nine of the eighty-two eligible living patients in whom the hips had not been revised again had satisfactory radiographs available for review at five to eleven years after the operation. In sixty-two (90%) of these patients, the acetabular implant was categorized as stable; in five (7%), the implant had a complete radiolucent line of <1 mm in width at the bone-implant interface but had no evidence of migration, position change, or screw breakage; and in two (3%), the acetabular component was categorized as definitely loose on the basis of migration. Neither of the patients with radiographic signs of acetabular loosening who had not undergone revision reported pain at the time of the latest follow-up (at five and seven years). One patient had new pelvic osteolysis during the follow-up period; the lesion was in the ilium (adjacent to zone 2 of the acetabular component) and was approximately 1 cm² in size on the anteroposterior radiograph of the pelvis.

Acetabular Failure Due to Loosening

Overall, two hips had a repeat revision because of aseptic loosening of the acetabular component and two others (both in asymptomatic patients) had definite loosening of the acetabular component. Two of the loose implants were Harris-Galante-I sockets, and two were Harris-Galante-II sockets. Before the index revision, all four of these hips had had a type-III defect (combined segmental and cavitary bone loss) according to the classification system of the American Academy of Orthopaedic Surgeons¹⁴. According to the system of Paprosky et al.², two hips had had a type-IIIa acetabular deficiency, one had had a type-IIIb deficiency, and one had had a type-IIc deficiency. The most recent anteroposterior radiographs of these four hips demonstrated that 0%, 43%, 50%, and 53% of the surface of the socket was in contact with allograft bone. The hip with no coverage by bone graft had previously been treated with therapeutic irradiation.

Component Survivorship

The probability of survival of the acetabular component at eight years was 93.0% (95% confidence interval, 85% to 100%) with revision or removal for any reason as the end point, 97.7% (95% confidence interval, 92% to 100%) with revision for aseptic loosening as the end point, and 94.8% (95% confidence interval, 88% to 100%) with revision for aseptic loosening or radiographic evidence of definite loosening as the end point.

Complications

The most frequent postoperative complication was dislocation, which occurred in eleven patients (12%). One of these patients had a repeat revision of the acetabular component, one had an exchange of the polyethylene liner, one had revision of the femoral component, and one had revision of the femoral component combined with an exchange of the polyethylene liner. The rest of the dislocations were treated without reoperation. Other complications included a palsy of the peroneal branch of the sciatic nerve (five patients), ileus (one patient), and deep infection (one patient). As mentioned previously, the deep infection was treated with resection arthroplasty.

Discussion

Introduction | Materials and Methods | Results | Discussion | References

The purpose of this study was to evaluate the results of one specific technique of revision surgery in patients with bone loss—namely, acetabular reconstruction with the use of an extra-large uncemented socket fixed with screws. The advantages of extra-large sockets are that (1) the acetabulum is prepared by reaming to a large hemisphere, a method that is technically straightforward; (2) most bone deficiencies are filled by the socket itself, thereby obviating the need for extensive bone-grafting; (3) there is increased contact area between the implant and the host bone; and (4) the center of hip rotation is translated to a more lateral and inferior (and hence, in most revisions, more normal) location. The disadvantages are that (1) extra-large sockets limit bone-stock restoration, and (2) large, oblong bone deficiencies cannot be filled in an inferior-to-superior direction without marked reaming of the anterior or posterior column or superior placement of the cup. As there are no widely accepted criteria for "extra-large" implants, we defined an extra-large implant as one with a diameter that was at least 10 mm larger than the mean diameter of implants of the same design that had been inserted during primary surgery. The minimum diameter of the implants in the present study was 66 mm for men and 62 mm for women.

As in other series of uncemented sockets inserted during revision surgery^2,16-20, these porous-coated hemispherical sockets performed well and had a low failure rate. Moskal et al. reported that 94% of thirty-two uncemented revision cups were stable after three to nine years of follow-up¹. Lachiewicz and Poon reviewed fifty-seven uncemented revision cups and found that none had loosened after a mean of seven years of follow-up²¹. Tanzer et al. reported that two of 140 revision cups had failed because of aseptic loosening after a mean of forty-one months of follow-up⁴. Silverton et al. reviewed 115 uncemented revision sockets and found that none had been revised for loosening and one was radiographically loose after seven to eleven years of follow-up³.

The current series demonstrates that, at the time of the intermediate-term follow-up, the extra-large uncemented socket can provide durable implant fixation, even in the presence of substantial bone loss. The few other studies on extra-large uncemented sockets also demonstrated favorable results^6,7. Jasty reviewed nineteen hips at a mean of ten years after the implantation of a "jumbo cup" and reported only one failure, which occurred in a patient with pelvic discontinuity⁶.

In the present study, all four of the failures that were due to aseptic acetabular loosening occurred in patients who had marked acetabular bone loss or who had had therapeutic irradiation of the pelvis. Therapeutic pelvic irradiation has been associated with a high risk of failure of uncemented sockets²². In the three patients in whom the loosening was not associated with irradiation, 43%, 50%, and 53% of the socket was seen to be in contact with allograft on the anteroposterior radiograph. The high rate of success in the present series speaks for the versatility of the technique but, at the same time, the few failures demonstrate its limitations. When massive acetabular bone loss precludes adequate initial implant stability or placement of the implant against sufficient host bone to provide a reasonable chance of long-term biologic fixation, other reconstruction techniques should be considered. Such techniques include the use of massive bulk^10,23,24 or particulate²⁵ bone grafts in association with a cemented socket, insertion of an antiprotrusio cage^26,27, and placement of an uncemented cup at a high hip center²⁸.

The most common complication in our series was dislocation, which occurred in eleven of the eighty-nine hips. Kelley et al. demonstrated a higher dislocation rate in association with the use of large uncemented sockets²⁹. Extra-large sockets may prevent the attachment of soft tissues (which would otherwise provide hip stability) close to the femoral head or may allow impingement of the femur against the acetabular component²⁹. Selective use of newer technologies, such as offset acetabular liners and constrained liners, may reduce the dislocation rate in the future.

The good results associated with extra-large sockets have encouraged us to use this method for most acetabular revisions in patients with moderate or marked, but not extreme, bone loss. Several technical points are important to the success of the technique. Circumferential exposure of the entire rim of the acetabulum is needed. Reaming is initiated by centering the reamer in the acetabular defect. Progressively larger reamers are used until a hemispherical bed of fresh acetabular bone has been prepared. The amount of reaming is important; sufficient reaming to create a hemisphere of supportive, biologically active bone is desirable, but excessive reaming that compromises the integrity of the remaining acetabular bone should be avoided. The goal is to provide implant support with as much host bone as possible, particularly around the periphery and against the acetabular dome. Usually, little medial reaming is required. Care should be taken to avoid reaming away the posterior wall and column, which are vital for implant support. When the superior-to-inferior dimension of the defect is much greater than the anterior-to-posterior dimension, an alternative reconstruction technique that preserves anterior and posterior walls and columns (such as reconstruction of the acetabulum at a high hip center or use of an oblong socket^30,31) should be considered. After reaming, trial implants are placed and the stability of the implant against supportive host bone is assessed. Remaining small-to-moderate cavitary or segmental bone defects can be filled with particulate bone graft that is packed with use of a reamer in the reverse mode. The bone graft should not compromise contact between the socket and the reamed host bone. A porous-coated hemispherical implant, usually about 2 mm larger than the last reamer used, is press-fit into the socket, and fixation is augmented with screws.

References

Introduction | Materials and Methods | Results | Discussion | References

Moskal JT, Danisa OA,Shaffrey CI. Isolated revision acetabuloplasty using a porous-coated cementless acetabular component without removal of a well-fixed femoral component. A 3- to 9-year follow-up study. J Arthroplasty,1997;12: 719-27. 12719 1997 [PubMed]

Paprosky WG, Perona PG,Lawrence JM. Acetabular defect classification and surgical reconstruction in revision arthroplasty. A 6-year follow-up evaluation. J Arthroplasty,1994;9: 33-44. 933 1994 [PubMed]

Silverton CD, Rosenberg AG, Sheinkop MB, Kull LR,Galante JO. Revision of the acetabular component without cement after total hip arthroplasty. A follow-up note regarding results at seven to eleven years. J Bone Joint Surg Am,1996;78: 1366-70. 781366 1996 [PubMed]

Tanzer M, Drucker D, Jasty M, McDonald M,Harris WH. Revision of the acetabular component with an uncemented Harris-Galante porous-coated prosthesis. J Bone Joint Surg Am,1992;74: 987-94. 74987 1992 [PubMed]

Emerson RH Jr,Head WC. Dealing with the deficient acetabulum in revision hip arthroplasty: the importance of implant migration and use of the jumbo cup. Semin Arthroplasty,1993;4: 2-8. 42 1993 [PubMed]

Jasty M. Jumbo cups and morsalized graft. Orthop Clin North Am,1998;29: 249-54.. 29249 1998 [PubMed]

Sutherland CJ. Management of type III acetabular deficiencies in revision total hip arthroplasty without structural bone graft. J South Orthop Assoc,1998;7: 36-42. 736 1998 [PubMed]

Harris WH. Traumatic arthritis of the hip after dislocation and acetabular fractures: treatment by mold arthroplasty. An end-result study using a new method of result evaluation. J Bone Joint Surg Am,1969;51: 737-55. 51737 1969 [PubMed]

Massin P, Schmidt L,Engh CA. Evaluation of cementless acetabular component migration. An experimental study. J Arthroplasty,1989;4: 245-51. 4245 1989 [PubMed]

Martell JM, Pierson RH 3rd, Jacobs JJ, Rosenberg AG, Maley M,Galante JO. Primary total hip reconstruction with a titanium fiber-coated prosthesis inserted without cement. J Bone Joint Surg Am,1993;75: 554-71. 75554 1993 [PubMed]

DeLee JG,Charnley J. Radiological demarcation of cemented sockets in total hip replacement. Clin Orthop,1976;121: 20-32. 12120 1976 [PubMed]

Engh CA, Bobyn JD,Glassman AH. Porous-coated hip replacement. The factors governing bone ingrowth, stem shielding, and clinical results. J Bone Joint Surg Br,1987;69: 45-55. 6945 1987 [PubMed]

Harris WH, McCarthy JC Jr,O’Neill DA. Femoral component loosening using contemporary techniques of femoral cement fixation. J Bone Joint Surg Am,1982;64: 1063-7. 641063 1982 [PubMed]

D’Antonio JA, Capello WN, Borden LS, Bargar WL, Bierbaum BF, Boettcher WG, Steinberg ME, Stulberg SD,Wedge JH. Classification and management of acetabular abnormalities in total hip arthroplasty. Clin Orthop,1989;243: 126-37. 243126 1989 [PubMed]

Kaplan EL,Meier P. Nonparametric estimation from incomplete observations. J Am Statist Assoc,1958;53: 457-81. 53457 1958

Garcia-Cimbrelo E. Porous-coated cementless acetabular cups in revision surgery: a 6- to 11-year follow-up study. J Arthroplasty,1999;14: 397-406.. 14397 1999 [PubMed]

Harris WH, Krushell RJ,Galante JO. Results of cementless revisions of total hip arthroplasties using the Harris-Galante prosthesis. Clin Orthop,1988;235: 120-6. 235120 1988 [PubMed]

Lachiewicz PF,Hussamy OD. Revision of the acetabulum without cement with use of the Harris-Galante porous-coated implant. Two to eight-year results. J Bone Joint Surg Am,1994;76: 1834-9. 761834 1994 [PubMed]

Padgett DE, Kull L, Rosenberg A, Sumner DR,Galante JO. Revision of the acetabular component without cement after total hip arthroplasty. Three to six-year follow-up. J Bone Joint Surg Am,1993;75: 663-73. 75663 1993 [PubMed]

Silverton CD, Rosenberg AG, Sheinkop MB, Kull LR,Galante JO. Revision total hip arthroplasty using a cementless acetabular component. Technique and results. Clin Orthop,1995;319: 201-8. 319201 1995 [PubMed]

Lachiewicz PF,Poon ED. Revision of a total hip arthroplasty with a Harris-Galante porous-coated acetabular component inserted without cement. A follow-up note on the results at five to twelve years. J Bone Joint Surg Am,1998;80: 980-4. 80980 1998 [PubMed]

Jacobs JJ, Kull LR, Frey GA, Gitelis S, Sheinkop MB, Kramer TS,Rosenberg AG. Early failure of acetabular components inserted without cement after previous pelvic irradiation. J Bone Joint Surg Am,1995;77: 1829-35. 771829 1995 [PubMed]

Garbuz D, Morsi E,Gross AE. Revision of the acetabular component of a total hip arthroplasty with a massive structural allograft. Study with a minimum five-year follow-up. J Bone Joint Surg Am,1996;78: 693-7. 78693 1996 [PubMed]

Jasty M,Harris WH. Salvage total hip reconstruction in patients with major acetabular bone deficiency using structural femoral head allografts. J Bone Joint Surg Br,1990;72: 63-7.. 7263 1990 [PubMed]

Slooff TJ, Buma P, Schreurs BW, Schimmel JW, Huiskes R,Gardeniers J. Acetabular and femoral reconstruction with impacted graft and cement. Clin Orthop,1996;324: 108-15. 324108 1996 [PubMed]

Berry DJ,Muller ME. Revision arthroplasty using an anti-protrusio cage for massive acetabular bone deficiency. J Bone Joint Surg Br,1992;74: 711-5. 74711 1992 [PubMed]

Gill TJ, Sledge JB,Müller ME. The Burch-Schneider anti-protrusio cages in revision total hip arthroplasty: indications, principles and long-term results. J Bone Joint Surg Br,1998;80: 946-53. 80946 1998 [PubMed]

Harris WH. Reconstruction at a high hip center in acetabular revision surgery using a cementless acetabular component. Orthopedics,1998;21: 991-2. 21991 1998 [PubMed]

Kelley SS, Lachiewicz PF, Hickman JM,Paterno SM. Relationship of femoral head and acetabular size to the prevalence of dislocation. Clin Orthop,1998;355: 163-70. 355163 1998 [PubMed]

Berry DJ, Sutherland CJ, Trousdale RT, Colwell CW Jr, Chandler HP, Ayres D,Yashar AA. Bilobed oblong porous coated acetabular components in revision total hip arthroplasty. Clin Orthop,2000;371: 154-60. 371154 2000 [PubMed]

DeBoer DK,Christie MJ. Reconstruction of the deficient acetabulum with an oblong prosthesis: three- to seven-year results. J Arthroplasty,1998;13: 674-80. 13674 1998 [PubMed]

Topics