Abstract
Background and aim of the work: To investigate the clinical, radiological and functional outcomes of acetabular revisions with acetabular reinforcement rings and cages. Methods: A comprehensive literature study of international databases was performed. Inclusion criteria were cementless revisions, use of reinforcement rings, radiological and clinical follow-up, availability of full text in English, publication between January 1990 and July 2018. In a second further analysis, we selected only studies describing patients with more severe acetabular defects (AAOS 3, AAOS 4, Paprosky III). Data extracted included mean follow-up period, radiographic follow-up, functional scores, implant failures and survival rate. Results: We included in our review 1327 acetabular revisions described in 28 articles. The most commonly used reinforcement rings were Burch-Schneider ring, the Muller ring and the Ganz ring. Mean follow-up for all patients together was 8.8 years. Clinical or radiological signs of loosening were reported in 191 patients, 83 patients needed further acetabular revision for aseptic loosening and 41 patients received additional surgeries for septic loosening. The mean value of the Harris Hip Score reported at the last follow-up was 76.3. Nineteen articles fulfilled the criteria for further analysis about high-grade acetabular bone defects. We analyzed 649 revisions with mean follow-up period of 8.2 years. Clinical or radiological loosening was reported in 90 patients, additional acetabular revision was performed in 39 patients and 25 patients needed further surgeries for deep infection. Conclusion: Acetabular revisions with cages are characterized by good survival rates and functional scores with a mean follow-up period of 8 years. (www.actabiomedica.it)
Keywords: revision arthroplasty, acetabulum, cage, reinforcement ring, acetabular bone defect, acetabular revision outcomes
Introduction
Total hip arthroplasty (THA) is a successful procedure to relieve pain and improve function in patients with end-stage degenerative hip joint diseases. Kurtz et al. (1,2) estimated that, in the USA, the number of THA will go beyond 50,000 per year by 2020 and will grow to 572,000 per year by 2030.
With the constant increase of THA and the increasing of life expectancy, the number of revision surgeries will rise as well and is estimated to increase by 137% by 2030 (2).
The main causes for acetabular revisions are aseptic loosening, infection, recurrent dislocations due to malposition of the components or abductor mechanism failure, periprosthetic fractures and mechanical failure of fixation (3, 4).
Acetabular revision is one of the most challenging procedures in hip arthroplasty surgery due to bone loss, poor quality of residual bone stock, poor soft tissue and migration of acetabular components (5). This loss of bone stock results from the initial disease, bone removal at the time of primary surgery and lysis caused by micromotion of prosthetic components and wear particles (6, 7).
Several reconstruction methods for acetabular revision and management of bone loss are reported in literature including: uncemented hemispherical acetabular components, impaction bone grafting with cemented a polyethylene component, structural allograft, jumbo revision shells, trabecular metal components, oblong shells, acetabular reinforcement rings and cages with or without bone grafts, custom-made triflange shells, stemmed shells, and tantalum augmentation with cementless cup (3, 8, 9). The goal of all of these techniques is to provide firm fixation of the acetabular components, preservation or reconstitution of the bone stock and positioning the acetabular component in the correct anatomical position to restore the correct center of rotation (10-12).
The aim of this systematic review is to evaluate the clinical, radiological and functional outcomes of revision THAs utilizing acetabular reinforcement rings or cages.
The rationale for the use of acetabular cages is to provide mechanical stability to the acetabular construct, protect bone graft/cup/augments transmitting the load to the host bone through the cage. Usually cages are indicated in segmental bone loss involving more than half of the acetabular surface, deficit of anterior and posterior columns and pelvic discontinuity (AAOS III-IV) (9).
Materials and methods
Search strategy
A comprehensive literature search of the Medline, PubMed Database (US National Library of Medicine, National Institutes of Health), Embase and Google Scholar was performed using defined search phrases.
Headings used for the search were “Cementless Acetabular Revision”, “Acetabular revision AND reinforcement ring” and “Acetabular revision AND cementless AND reinforcement rings”.
This initial research included articles published between January 1990 and July 2018 evaluating clinical and radiological outcomes and failure rate of THA revisions with reinforcement rings and cages.
Inclusion criteria were: cementless revisions (between cage and host bone), acetabular revision with the use of reinforcement rings, both radiological and clinical follow-ups, and availability of the full text in English.
We excluded from our study review articles, single case report and THA revisions due to deep infection.
Studies were first screened based on the title and abstract. Full text analysis confirmed the inclusion in the review. Citations within selected papers were reviewed to identify additional studies.
In a second analysis we selected only studies about patients with more severe acetabular defects (AAOS 3, AAOS 4 and Paprosky III). AAOS 3 defects are combined cavitary and segmental defects. AAOS 4 correspond to pelvic discontinuity. Paprosky III defect included major destruction of supporting structures and acetabular rim.
We defined the failure of the acetabular component as the need for a new revision or radiological signs of loosening of the implant. The criteria for radiographic loosening included: horizontal or vertical migration bigger than 2-5 mm, a change in acetabular tilt >3°-5°, progressive radiolucent lines, breaking of screws or reinforcement rings (8, 13-17). We classified failure into septic and aseptic.
Data extraction
Data extracted from the selected studies included authors, journal and year of publication, number of included THA revisions, mean follow-up (FU), mean patient age at time of surgery, radiographic FU, post-operative functional score, implant failure and survival rate.
Results
After the exclusion of duplicates, there were a total of 679 abstracts (634 - “cementless acetabular revision”; 42 - “acetabular revision and reinforcement rings”; 3 - “acetabular revision and cementless and reinforcement rings”). 644 publications were excluded based on title and abstract and 7 more articles were excluded after analyzing the full text. Consequently, we included in our review 28 articles.
For the second analysis based on severe acetabular defect only 19 publications fulfilled the inclusion criteria.
Due to the nature of the study, all the articles were retrospective cases of THA revisions using reinforcement rings. Randomized control trials (RCTs) were not available.
All cases (All bone defects)
We analyzed 28 articles published between 1990 and 2018 that reported the outcomes of ten different kinds of reinforcement rings (Table 1). The most commonly used reinforcement rings were the Burch-Schneider ring (13 articles), the Muller ring (12 articles), and the Ganz ring (4 articles). All the other reinforcement rings (Custom-made cage, KT Plates, MRS-Titan, Murata-Chiba support ring, ZCA Reconstruction cage, Kerboull ring) were analyzed in only 1 article each except for Contour reinforcement and reconstruction rings that were described in 2 different studies.
Table 1.
| Author | Reinforcement ring | Hips(N°) | Mean FU (years) | Mean age (years) | Loosening (clinical / radiological) | Revision-Aseptic Loosening | Revision-Septic Loosening | Functional Score (mean score) | Survival rate |
| Beckmann [5] | Gan. | 119 | 16(15-18) | 65 (26-90) | 19 | 15 | 4 | HHS 77; womuoi 64,5; sfl2 PCS 32 MCS 55.9; NRS > 50% no pain | survival rate 90,1% (82,6-94,4%) |
| Berry [7] | Burch-Schneider | 42 | 5(2-11) | 61,7 | 12 | 5 | 5 | Merle d’Aubignè (pain score 3.2 to 4,8; walking score 4,4 to 5; motion score 4,2 to 5,1) | |
| Bohm [29] | Muller | 39 | 4,2 (1-13) | 61 (31-86) | 2 | 1 | 1 | X | worst-case criterion survival rate (revision\deep infection\loss to FU) 84% at 13yers survival rate 89% at 11 years survival rate worst-case criterion (revision\deep infection\loss to FU) 83% 11 years |
| Bohm [29] | Burch-Schneider | 26 | 5,3 (0,5-11) | 61 (31-86) | 2 | 1 | 1 | X | |
| Bruggemann [4] | Muller | 96 | 12 (2,3-17) | 69 (40-95) | 9 | 8 | 1 | X | |
| Eggli [18] | Ganz | 5 | 8 (4,5-10,9) | 61,7 (50-72) | 2 | 2 | 0 | Merle d’Aubignè from 7,5 to 13.2; HHS from 33 to 73 | |
| Eggli [18] | Muller | 2 | 8 (4,5-10,9) | 61,7 (50-72) | 0 | 0 | 0 | Merle D’Aubignè from 7,5 to 13.2 HHS from 33 to 73 |
|
| Gaiani [19] | Burch-Schneider | 46 | 6 (2-10) | 82 (78-85) | 0 | 0 | 0 | HHS from 28,2 to 82,5 (62,2-94,8) 1 severe pain, 4 moderate pain |
|
| Garbuz [20] | Burch-Schneider | 8 | 7,5(5-11) | 60 (32-85) | 1 | 0 | 1 | HHS from 29 to 73 | |
| Gerber [17] | Gan, | 50 | 9 (7,8-11,6) | 69 (53-86) | 7 | 3 | 1 | Merle d’Aubignè from 11 to 16 | survival rate 81% at FU survival rate 85% at 10 years for adequate reconstruction survival rate 57% at 10 years for inadequate reconstruction |
| Goodmann [30] | Burch-Schneider | 42 | 4,6 (2-19) | 65,2 (33-93) | 9 | 4 | 2 | X | 76% success: no dislocation, no loosening, no revisions |
| Goodmann [30] | Contour | 19 | 4,6 (2-19) | 65,2 (33-93) | 9 | 4 | 2 | X | |
| llchmann [21] | Burch-Schneider | 40 | 4,7 (2,3-6,9) | 70 (36-81) | 16 | 2 | 0 | HHS 72 at last FU | |
| Jain [22] | Muller (22) | 24 | 2,8 (1,1-4,5) | 72,7 (66,3-79,1) | 1 | 1 | 0 | HHS 44,2 (SD 23.3) | |
| Burch-Schneider (2) | SF36: all parameters worst than general population | ||||||||
| Kokubo [14] | KT Plates (34) | 47 | 15,6 (10-32) | 65,8 (45-85) | 12 | 8 | 0 | HH S from 40.9 (18-58) to 72.1 (32-92) | |
| Muller (8) | |||||||||
| Kerboull (5) | |||||||||
| Korowessis [32] | Muller | 10 | 2,5 (1-5) | 61 (31-83) | 0 | 0 | 0 | Mayo Clinic Hip scale: 60% good-excellent; 40% moderate-fair | |
| Levai [35] | Muller | 28 | 3,1 (34) | 66,1 (55-76) | 2 | 2 | 0 | Merle D’Aubignè from 9,1 to 14.9 | |
| Levai [35] | Burch-Schneider | 2 | 3,1 (34) | 66,1 (55-76) | 0 | 0 | 0 | Merle D’Aubignè from 9,1 to 14.9 | |
| Li [15] | custom cages | 24 | 5,6 (2-10) | 65 (54-79) | 1 | 0 | 0 | HHS from 36 (20-49) to 82 (60-96) | |
| Makinen [34] | ZCA Reconstruction Cage+ porous metal augment | 22 | 3(24,6) | 70 (27-85) | 3 | 2 | 0 | Oxford hip score from 13,9 (2-23) to 28,7 (13-38) | loosening: patients with previous oncological resection of acetabulum survival rate 90,9% at 36 months; 75,7% at 55 months |
| Murali Krishnan [11] | Contour | 45 | 7,1 (3,5-8,8) | 75,6 (31-95) | 2 | 0 | 3 | HHS: 16 excellent-good, 6 fair,4 poor | |
| reinforcement ring (23) | |||||||||
| Contour | |||||||||
| reconstruction ring (22) | |||||||||
| Ochs [23] | Burch-Schneider | 79 | 2,6 (1,24,2) | 71,2 (46-90) | 20 | 0 | 0 | HHS 70,4 (1,5-97,1) | |
| Panski [28] | Muller | 11 | 3,3 (0,5-7) | 61,3 (42-86) | 1 | 1 | 0 | 9 patients satisfied at FU | |
| Rosson [6] | Muller | 46 | 5 (2-10) | 63 (32-79) | 10 | 5 | 0 | HHS 87 (61-100) at FU | |
| Rosson [6] | Burch-Schneider | 20 | 5 (2-10) | 62 (22-73) | 0 | 0 | 0 | HHS 81(56-99) | |
| Schatzker [24] | Muller | 57 | 8,3 | 62,9 | 9 | 8 | 1 | HHS from 42,7 to 84,8 | il rate 92 3"/at 10 years |
| SF36 40 physical e 56 mental | |||||||||
| Schatzker [24] | Burch-Schneider | 38 | 6,6 | 66,8 | 2 | 0(2 awaiting revision) | 0 | HHS from 45,9 to 82,8 | survival rate 91,7% at 10 years |
| SF36 physical 41, mental 54 | |||||||||
| Schiegei [27] | Muller | 109 | 6(2-17) | 69 (29-92) | 12 | 6 | 7 | HHS 70 (20-100) at FU | survival rate 95% at 5years, 90% at 8years |
| 52% HHS<70 poor score | aseptic survival rate 98% at 5 years, 95% at 8 years | ||||||||
| Merle d’Aubignè 7 (0-12) | |||||||||
| Schmoiders [25] | MRS-Titan | 39 | 2,6(14,3) | 67 (43-88) | 6 | 1 | 5 | HHS from 27 (13-41) to 76 (61-91) | |
| survival rate 84% al FU | |||||||||
| Stock! [33] | Muller | 49 | 6,4 (5,9-9) | 67,8 (43,5-84) | 8 | 2 | 2 | 30% no support for walking | |
| 59% mild pain | |||||||||
| Uchiyama [12] | Ganz | 30 | 8(3-17,8) | 60,8 (41-80) | 5 | 0 | 0 | X | survival rate 96% at 5years, 80,2% at 10years |
| van der Linde [16] | Burch-Schneider | 16 | 11,7 (6,8-16,2) | 67,4 (37-83) | 1 | 0 | 1 | Merle d’Aubignè from 9,8 to 14,4 | |
| van del Linde [16] | Muller | 26 | 9,2 (6,4-13,2) | 67,7 (45-87) | 3 | 1 | 2 | Merle d’Aubignè from 9,5 to 14 | |
| Winter [26] | Burch-Schneider | 38 | 7,3 (4,2-9,4) | 76 (49-83) | 0 | 0 | 0 | HHS 82,6 (58,2-94,9) | |
| survival rate 100% at FU | |||||||||
| Yoshino [8] | Murata-Chiba support ring | 33 | 17,6 (15-22,9) | 54,1 (42,9-65,3) | 5 | 1 | 2 (resection Arthroplasty) | HHS from 44,3 (7.79) to 77,2 (55-97) | |
| survival rate 90,6% at 15 years (100% AAOS II; 97,6% AAOS III) |
We included in our review 1327 patients who had had acetabular revision with reinforcement rings and in 83.3% of them (1106 patients) one of the three most commonly used reinforcement rings was used.
Analyzing all the patients together, the mean follow-up period was 8.8 years (0,5-22,9) and the mean age at the time of acetabular revision was 64.5 years (26-95). Clinical or radiological signs of loosening were reported in 191 (14,4%) patients. Eighty-three (6,3%) patients needed further acetabular revision for aseptic loosening and 41 (3.1%) patients received additional surgeries for septic loosening.
The most commonly reported functional score was the Harris Hip Score (HHS) and the mean value at the time of FU was 76.3. All the authors that used the HHS for the clinical FU reported a significant increase of the score after the acetabular revision (5, 6, 8, 11, 14, 15, 18-26).
Five hundred and three patients (37.9%) had had a Muller ring placed. These patients had a mean FU period of 5.9 years, a mean age at the time of surgery of 65.3 years and a rate of loosening of 11.9%. A Burch-Schneider ring was placed in 399 patients (30%) with a mean FU period of 5.6 years, mean age of 57.3 years and a rate of loosening of 15.8%. The Ganz ring was used in 204 THA revisions (15.4%). The mean FU period was 10.3 years, the mean age at surgery was 64.1 years and the rate of loosening was 16.2% (table 2).
Table 2.
| Reinforcement ring | Hips (N°) | Mean FU (years) | Mean age (years) | Loosening (clinical / radiological) | Revision - Aseptic Loosening | Revision - Septic Loosening |
| Ganz (4) | 204 | 10,3 | 64,1 | 33 | 20 | 5 |
| Burch-Schneider (13) | 399 | 5,6 | 57,3 | 63 | 12 | 10 |
| Contour (2) | 64 | 5,85 | 70,4 | 11 | 4 | 5 |
| Custom Cages (1) | 24 | 5,6 | 65 | 1 | 0 | 0 |
| KT Plates (1) | 34 | 15,6 | 65,8 | 5 | 3 | 0 |
| MRS-Titan (1) | 39 | 2,6 | 67 | 6 | 1 | 5 |
| Muller (12) | 503 | 5,9 | 65,3 | 60 | 36 | 14 |
| Murata-Chiba support ring (1) | 33 | 17,6 | 54,1 | 5 | 1 | 2 |
| ZCA Reconstruction Cage (1) | 22 | 3 | 70 | 3 | 2 | 0 |
| Kerboull (1) | 5 | 15,6 | 65,8 | 4 | 4 | 0 |
| TOTAL | 1327 | 8,8 (0,5-22,9) | 64,5 (26-95) | 191 | 83 | 41 |
High-grade bone defect cases
Nineteen articles published between 1992 and 2018 fulfilled the criteria for our further analysis (table 3).
Table 3.
| Author | Reinforcement ring | Hips (N°) AAOS 3-4 / Paprosky llla- lllb | Mean FU (years) | Mean age (years) | Loosening (clinical / radiological) | Revision - Aseptic Loosening | Revision - Septic Loosening | Functional Score |
| Beckmann [5] | Ganz | 68 | 16 (15-18) | 65 (26-90) | 12 | X | HHS 77; womuoi 64,5; sf12 PCS 32 MCS 55.9; NRS > 50% non dolore | |
| Berry [7] | Burch-Schneider | 42 | 5 (2-11) | 61,7 | 12 | 5 | 5 | Merle d’Aubignè (pain score 3.2 to 4,8; walking score 4,4 to 5; motion score 4,2 to 5,1) |
| Bohm [29] | Muller | 14 | 4,2 (1-13) | 61 (31-86) | 1 | 1 | 0 | X |
| Bohm [29] | Burch-Schneider | 20 | 5,3 (0,5-11) | 61 (31-86) | 1 | 1 | 0 | X |
| Bruggemann [4] | Muller | 32 | 12 (2,3-17) | 69 (40-95) | 1 | 1 | 0 | X |
| Eggli [18] | Ganz | 5 | 8 (4,5-10,9) | 61,7 (50-72) | 2 | 2 | 0 | Merle D’Aubignè from 7,5 to 13.2 |
| HHS from 33 to 73 | ||||||||
| Eggli [18] | Muller | 2 | 8 (4,5-10,9) | 61,7 (50-72) | 0 | 0 | 0 | Merle D’Aubignè from 7,5 to 13.2 |
| HHS from 33 to 73 | ||||||||
| Gaiani [19] | Burch-Schneider | 46 | 6 (2-10) | 82 (78-85) | 0 | 0 | 0 | HHS from 28,2 to 82,5 (62,2-94,8) |
| Garbuz [20] | Burch-Schneider | 8 | 7,5 (5-11) | 60 (32-85) | 1 | 0 | 1 | X |
| Gerber [17] | Ganz | 26 | 9 (7,8-11,6) | 69 (53-86) | 5 | 3 | 1 | Merle d’Aubignè from 11 to 16 |
| Goodmann [30] | Burch-Schneider | 35 | 4,6 (2-19) | 65,2 (33-93) | 8 | 3 | 2 | X |
| Goodmann [30] | Contour | 13 | 4,6 (2-19) | 65,2 (33-93) | 9 | 4 | 2 | X |
| Kokubo [14] | KT Plates (34) | 47 | 15,6 (10-32) | 65,8 (45-85) | 12 | 8 | 0 | HHS from 40.9 (18-58) to 72.1 (32-92) |
| Muller (8) | ||||||||
| Kerboull (5) | ||||||||
| Levai [35] | Muller | 6 | 3,1 (3-4) | 66,1 (55-76) | 1 | 1 | 0 | X |
| Levai [35] | Burch-Schneider | 2 | 3,1 (3-4) | 66,1 (55-76) | 0 | 0 | 0 | X |
| Li [15] | Custom Cages | 24 | 5,6 (2-10) | 65 (54-79) | 0 | 0 | HHS from 36 (20-49) to 82 (60-96) | |
| Makinen [34] | ZCA Reconstruction Cage+ porous metal augment | 22 | 3 (2-4,6) | 70 (27-85) | 3 | 2 | 0 | Oxford hip score from 13,9 (2-23) to 28,7 (13-38) |
| Murali Krishnan [ | Contour reinforcement ring (13) Contour reconstruction ring (18) | 31 | 8 (3,5-8,8) | 75,6 (31-95) | 0 | 0 | 0 | X |
| Rosson [6] | Muller | 1 | 5 (2-10) | 63 (32-79) | 1 | 1 | 0 | X |
| Rosson [6] | Burch-Schneider | 15 | 5 (2-10) | 62 (22-73) | 0 | 0 | 0 | X |
| Schlegel [27] | Muller | 100 | 6 (2-17) | 69 (29-92) | 12 | 6 | 7 | HHS 70 (20-100) at FU |
| 52% HHS<70 poor score | ||||||||
| Merle d’Aubignè 7 (0-12) | ||||||||
| Schmolders [25] | MRS-Titan | 39 | 2,6 (2-4,3) | 67 (43-88) | 6 | 1 | 5 | HHS from 27 (13-41) to 76 (61-91) |
| van der Linde [16] | Burch-Schneider | 6 | 11,2 (8,5-13,9) | 61 (37-77) | 0 | 0 | 0 | Merle d’Aubignè from 9,8 to 16 |
| van del Linde [16] | Muller | 7 | 9,7 (8,3-13,2) | 65 (51-78) | 2 | 0 | 2 | Merle d’Aubignè from 8,6 to 13,4 |
| Winter [26] | Burch-Schneider | 38 | 7,3 (4,2-9,4) | 76 (49-83) | 0 | 0 | 0 | HHS 82,6 (58,2-94,9) |
There were 649 revision THAs described with a preoperative acetabular bone defect classified as AAOS 3-4 or Paprosky IIIa-IIIb. The mean age at surgery was 66.7 years and the mean FU period was 8.2 years. Clinical or radiological loosening was reported in 90 patients with a consequently rate of loosening of 13.9%. Additional acetabular revision was performed in 39 patients (6%) and 25 (3.9%) patients needed further surgeries for deep infection.
The Burch-Schneider ring was used in 212 patients (32.7%). The mean FU period was 6,1 years and the rate of loosening was 10,4%. In 170 acetabular revisions (26.2%) a Muller ring was used. The average FU time was 7,9 years and the loosening rate was 12.4%. The Ganz ring was used in 99 THAs revisions (15.3%). The mean FU period was 11 years and the rate of loosening was 19.2% (table 4).
Table 4.
| Reinforcement ring | Hips (N°) AAOS 3-4 / Paprosky IIIa-IIIb | Mean FU (years) | Mean age (years) | Loosening (clinical / radiological) | Revision - Aseptic Loosening |
| Burch-Schneider (9) | 212 | 6,1 | 66,1 | 22 | 9 |
| Contour (2) | 44 | 6,3 | 70,4 | 9 | 4 |
| Custom Cages (1) | 24 | 5,6 | 65 | 1 | 0 |
| Ganz (3) | 99 | 11 | 65,2 | 19 | 5 |
| KT Plates (1) | 34 | 15,6 | 65,8 | 5 | 3 |
| MRS-Titan (1) | 39 | 2,6 | 67 | 6 | 1 |
| Muller (8) | 170 | 7,9 | 65,1 | 21 | 11 |
| Kerboull (1) | 5 | 15,6 | 65,8 | 4 | 4 |
| ZCA Reconstruction Cage (1) | 22 | 3 | 70 | 3 | 2 |
| TOTAL | 649 | 8,2 | 66,7 | 90 | 39 |
Only eight authors reported the Harris Hip Score at the last follow up (5, 14, 15, 18, 19, 25-27). The average HHS at the time of the last FU was 76.5.
Discussion
Our review summarize clinical, radiological and functional outcome of acetabular revisions with deficient bone stock treated with a reinforcement ring.
Acetabular revision is still one of the most challenging procedures in hip arthroplasty surgery due to bone loss, poor quality of residual bone stock, poor soft tissue and migration of acetabular components (5). Deficiency of bone stock results from the initial osteoarthritic process, bone reaming at the time of primary surgery and lysis caused by micromotion of prosthetic components and wear particles (7, 11, 22, 28).
Several surgical techniques are reported in literature for acetabular revision and the management of bone loss (3, 8, 9). More recently, cages are usually indicated in severe acetabular bone loss involving more than half of the acetabular surface, medial wall deficiency, pelvic discontinuity and when it is not possible to achieve primary stability with hemispherical cemented or uncemented cups (16). The rationale for the use of cages is to obtain mechanical stability to the prosthetic acetabulum and to protect the allograft or the augments transmitting the load through the cage to the pelvic host bone (9, 15, 18, 21). Two main kinds of acetabular cages are described in literature: antiprotrusio cages and acetabular roof rings. The antiprotrusio cages are characterized by double flanges for the ilium and the ischium. Whereas, acetabular roof rings may or may not have a hook for cotyloid notches and usually do not have flanges for the ilium (9). Van der Linde et al. (16) reported that the only absolute indication for antiprotusio cages is pelvic discontinuity while for other acetabular defects the selection of the reinforcement rings depends on which fit best in the acetabulum. Other authors (6, 12, 29, 30) instead, underline that in the presence of segmental medial defects acetabular roof rings are insufficient to guarantee mechanical stability to the construct.
Obtaining the proper anatomical position of the socket is fundamental to re-establish the right center of rotation of the hip, but can be challenging in acetabular revision in cases with severe bone loss. Shutzer and Harris (31) in 1994 suggested high placement of the acetabulum to obtain sufficient contact between the prosthesis and the host bone. Instead, several more recent articles reported a higher incidence of acetabular loosening in these cases (11, 12, 15, 18-21, 24, 25, 32, 33). In these cases, the use of graft and reinforcement rings to reestablish the right center of rotation is strongly suggested.
In our review we analyzed 1327 acetabular revisions reported in 28 articles with a mean follow-up of 8.8 years. Clinical or radiological sign of loosening was present in 14.4% of cases and 6.3% of patients underwent further acetabular revision for aseptic loosening. The most commonly reported functional score was the Harris Hip Score (HHS) and the mean value at the time of FU was 76.3 (poor results were considered to be inferior to 70 points). All the authors that used the HHS for the clinical FU reported a significant increase of the score after the acetabular revision (6, 8, 10, 11, 14, 15, 18-27). In our further analysis, we considered only acetabular revisions with high-grade bone defect. We did not encounter significant differences in the loosening rate and the need of further acetabular revision between the “all defect group” and the “high-grade defect group”. In both groups, the Ganz ring was characterized by a higher loosening rate.
Recently, newer porous metal implants have been introduced. Their advantages are porous surfaces, lower modulus of elasticity and higher coefficients of friction. All of these characteristics are thought to increase and accelerate bone ingrowth. Trabecular metal hemispherical cup and augments could be an alternative solution to cages in high grade bone defect acetabular revision (34). Beckmann et al. (10), in their review, reported a lower loosening rate of trabecular metal cups compared with acetabular cages. The authors strongly suggest the use of trabecular metal cups also in high-grade bone defect acetabular revision. However, long-term results are not yet available in literature.
References
- 1.Kurtz SM, Ong KL, Lau E, Bozic KJ. Impact of the economic downturn on total joint replacement demand in the united states. Uploaded projection to 2021. J Bone Joint Surg Am. 2014;96:624–630. doi: 10.2106/JBJS.M.00285. [PMID:24740658 DOI: 10.2106/JBJS.M.00285] [DOI] [PubMed] [Google Scholar]
- 2.Kurtz S, Kevin O, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the united states from 2005 to 2030. J Bone Joint Surg Am. 2007;89:780–85. doi: 10.2106/JBJS.F.00222. [PMID 17403800 DOI 10.2106/JBJS.F.00222] [DOI] [PubMed] [Google Scholar]
- 3.Volpin A, Konan S, Biz C, Tansey RJ, Haddad FS. Reconstruction of failed acetabular component in the presence of severe acetabular bone loss: a systematic review. Musculoskelet Surg. 2018 Apr 13 doi: 10.1007/s12306-018-0539-7. [PMID 29654551 DOI 10.1007/s12306-018-0539-7] [DOI] [PubMed] [Google Scholar]
- 4.Brüggemann A, Fredlund E, Mallmin H, Hailer NP. Are porous tantalum cups superior to conventional reinforcement rings? A retrospective cohort study of 207 acetabular revisions. Acta Orthop. 2017;88(1):35–40. doi: 10.1080/17453674.2016.1248315. [PMID 27892748 PMCID PMC5251262 DOI 10.1080/17453674.2016.1248315] [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Beckmann NA, Hasler JF, Moradi B, Schlegel UJ, Gotterbarm T, Streit MR. Long-term results of acetabular reconstruction using ganz acetabular rings. J. Arthroplasty. 2018 Jul;4:1–7. doi: 10.1016/j.arth.2018.06.036. [PMID PMID: 30060906 DOI 10.1016/j.arth.2018.06.036] [DOI] [PubMed] [Google Scholar]
- 6.Rosson J, Schatzker J. The use of reinforcement rings to reconstruct deficient acetabula. J. Bone Joint Surg Br. 1992;74(5):716–720. doi: 10.1302/0301-620X.74B5.1527120. [PMID: 1527120] [DOI] [PubMed] [Google Scholar]
- 7.Berry DJ, Muller ME. Revision arthroplasty using an anti-protrusio cage for massive acetabular bone deficiency. J. Bone Joint Surg Br. 1992 Sep;74(5):711–5. doi: 10.1302/0301-620X.74B5.1527119. [PMID 1527119] [DOI] [PubMed] [Google Scholar]
- 8.Yoshino K, Tsukeoka T, Tsuneizumi Y, Lee TH, Nakamura J, Suzuki M, Ohtori S. Revision total hip arthroplasty using a cementless cup supporter and iliac autograft : a minimum of 15-year follow-up. J. Arthroplasty. 2017;32(11):3495–3501. doi: 10.1016/j.arth.2017.06.026. [PMID 28697865 DOI 10.1016/j.arth.2017.06.026] [DOI] [PubMed] [Google Scholar]
- 9.Makinen TJ, Kuzyk P, Safir OA, Backstein D, Gross AE. Current concepts review: Role of cages in revision arthroplasty of the acetabulum. J Bone Joint Surg Am. 2016;98(3):233–242. doi: 10.2106/JBJS.O.00143. [PMID 26842414 DOI 10.2106/JBJS.O.00143] [DOI] [PubMed] [Google Scholar]
- 10.Beckmann NA, Weiss S, Klotz MCM, Gondan M, Jaeger S, Bitsch RG. Loosening after acetabular revision: Comparison of trabecular metal and reinforcement rings. A systematic review. J. Arthroplasty. 2014;29(1):229–235. doi: 10.1016/j.arth.2013.04.035. [PMID 23719095 DOI 10.1016/j.arth.2013.04.035] [DOI] [PubMed] [Google Scholar]
- 11.Murali Krishnan K, Longstaff L, Partington P. Acetabular reconstruction using morcellised bone with ring support. Medium term results at three to nine years. Acta Orthop. Belg. 2011;77(1):61–67. [PMID 21473447] [PubMed] [Google Scholar]
- 12.Uchiyama K, Takahira N, Fukushima K, Yamamoto T, Moriya M, Itoman M. Radiological evaluation of allograft reconstruction in acetabulum with Ganz reinforcement ring in revision total hip replacement. J. Orthop. Sci. 2010;15(6):764–771. doi: 10.1007/s00776-010-1549-y. [PMID 21116894 DOI 10.1007/s00776-010-1549-y] [DOI] [PubMed] [Google Scholar]
- 13.DeLee J, Charnley J. Radiological demarcation of cemented sockets in total hip replacement. Clin Orthop Relat Res. 1976;121:20–32. [PMID 991504] [PubMed] [Google Scholar]
- 14.Kokubo Y, Oki H, Sugita D, Negoro K, Takeno K, Miyazaki T, Nakajima H. Long-term clinical outcome of acetabular cup revision surgery: comparison of cemented cups, cementless cups, and cemented cups with reinforcement devices. Eur J Orthop Surg Traumatol. 2016;26(4):407–413. doi: 10.1007/s00590-016-1763-1. [PMID 27010392 DOI 10.1007/s00590-016-1763-1] [DOI] [PubMed] [Google Scholar]
- 15.Li H, Qu X, Mao Y, Dai K, Zhu Z. Custom Acetabular Cages Offer Stable Fixation and Improved Hip Scores for Revision THA With Severe Bone Defects. Clin Orthop Relat Res. 2016;474:731–740. doi: 10.1007/s11999-015-4587-0. [PMID 26467611 PMCID PMC4746190 DOI 10.1007/s11999-015-4587-0] [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.van der Linde M, Tonino A. Acetabular revision with impacted grafting and a reinforcement ring: 42 patients followed for a mean of 10 years forcement ring. Acta Orthop Scand. 2001;72:221–227. doi: 10.1080/00016470152846510. [PMID 11480594 DOI 10.1080/00016470152846510] [DOI] [PubMed] [Google Scholar]
- 17.Gerber A, Pisan M, Zurakowsi D, Isler B. Ganz Reinforcement Ring for Reconstruction of Acetabular Defects in Revision Total Hip. J Bone Joint Surg. 2003;85(A(12)):2358–2364. doi: 10.2106/00004623-200312000-00013. [PMID 14668505] [DOI] [PubMed] [Google Scholar]
- 18.Eggli S, Müller C, Ganz R. Revision Surgery in Pelvic Discontinuity. Clin Orthop Relat Res. 2002;398:136–145. [PMID 11964643] [PubMed] [Google Scholar]
- 19.Gaiani L, Bertelli R, Palmonari M, Vicenzi G. Total hip arthroplasty revision in elderly people with cement and Burch-Schneider anti-protrusio cage. Musculoskelet Surg. 2009;93(1):15–19. doi: 10.1007/s12306-009-0019-1. [PMID 19711157 DOI 10.1007/s12306-009-0019-1] [DOI] [PubMed] [Google Scholar]
- 20.Garbuz DON, Morsi E, Gross AE. Revision of the Acetabular Component of a Total Hip Arthroplasty with a Massive Structural Allograft. J bone Joint Surg. 1996;78(5):693–697. doi: 10.2106/00004623-199605000-00008. [PMID 8642025] [DOI] [PubMed] [Google Scholar]
- 21.Ilchmann T, Gelzer JP, Winter E, Weise K. Acetabular reconstruction with the Burch-Schneider ring: An EBRA analysis of 40 cup revisions Acetabular reconstruction with the Burch-Schneider. Acta Orthop. 2006;77(1):79–86. doi: 10.1080/17453670610045722. [PMID 16534705 DOI 10.1080/17453670610045722] [DOI] [PubMed] [Google Scholar]
- 22.Jain R, Schemitsch EH, Waddell JP. Functional outcome after acetabular revision with roof reinforcement rings. Can J Surg. 2000;43(4):276–282. [PMID 10948688 PMCID PMC3695216] [PMC free article] [PubMed] [Google Scholar]
- 23.Ochs B, Schmid U, Rieth J, Ateschrang A, Weise K, Ochs U. Acetabular bone reconstruction in revision arthroplasty: a compariso of freeze-dried, irradiated and chemically-treated allograft vitalised with autologous morrow versus frozen non-irradiated allograft. J bone Joint Surg Br. 2008;90(9):1164–1171. doi: 10.1302/0301-620X.90B9.20425. [PMID 18757955 DOI 10.1302/0301-620X.90B9.20425] [DOI] [PubMed] [Google Scholar]
- 24.Schatzker J, Wong MK. Acetabular Revision The Role of Rings and Cages. Clin Orthop Relat Res. 1999;369:187–197. [PMID 10611874] [PubMed] [Google Scholar]
- 25.Schmolders J, Friedrich J, Michel RD, Randau TM, Wimmer MD, Strauss AC, Kohlhof H, Wirtz DC, Gravius S. Acetabular defect reconstruction in revision hip arthroplasty with a modular revision system and biological defect augmentation. Int Orthop. 2015;39(4):623–630. doi: 10.1007/s00264-014-2533-5. [PMID 25277762 DOI 10.1007/s00264-014-2533-5] [DOI] [PubMed] [Google Scholar]
- 26.Winter E, Piert M, Volkmann R, Maurer F, Eingartner C, Weise K, Weller S. Allogeneic Cancellous Bone Graft and a Burch-Schneider Ring for Acetabular Reconstruction in Revision Hip Arthroplasty. J bone Joint Surg. 2001;83-A(6):862–867. doi: 10.2106/00004623-200106000-00007. [PMID 11407794] [DOI] [PubMed] [Google Scholar]
- 27.Schlegel UJ, Bitsch RG, Pritsch M, Clauss M, Mau H, Breusch SJ. Mueller reinforcement rings in acetabular revision Outcome in 164 hips followed for 2 - 17 years. Acta Orthop. 2006;77(2):234–241. doi: 10.1080/17453670610045966. [PMID 16752284 DOI 10.1080/17453670610045966] [DOI] [PubMed] [Google Scholar]
- 28.Panski A, Tauber C. Acetabular supporting ring in total hip replacement. Arch. Orthop Trauma Surg. 1997;116(4):233–235. doi: 10.1007/BF00393718. [PMID: 9128780] [DOI] [PubMed] [Google Scholar]
- 29.Böhm P, Banzhaf S. Acetabular revision with allograft bone : 103 revisions with 3 reconstruction alternatives , followed for 0.3 - 13 years. Acta Orthop Scand. 1999 Jun;70(3):240–9. doi: 10.3109/17453679908997800. [PMID 10429598] [DOI] [PubMed] [Google Scholar]
- 30.Goodman S, Saastamoinen H, Shasha N, Gross A. Complications of Ilioischial Reconstruction Rings in Revision Total Hip Arthroplasty. J. Arthroplasty. 2004;19(4):436–46. doi: 10.1016/j.arth.2003.11.015. [PMID 15188101] [DOI] [PubMed] [Google Scholar]
- 31.Schutzer S, Harris W. High placement of porous-coated acetabular components in complex total hip arthroplasty. J. Arthroplasty. 1994 Aug;9(4):359–67. doi: 10.1016/0883-5403(94)90045-0. [PMID 7964766] [DOI] [PubMed] [Google Scholar]
- 32.Korovessis P, Spastris P, Sdougos G, Salonikides P, Christodoulou G, Katsoudas G. Acetabular Roof Reinforcement Rings. Clin Orthop Relat Res. 1992 Oct;283:149–55. [PMID 1395239] [PubMed] [Google Scholar]
- 33.Stockl B, Beerkotte J, Krismer M, Fischer M, Bauer R. Results of the Muller acetabular reinforcement ring in revision arthroplasty. Arch Orthop Trauma Surg. 1997;116(1-2):55–9. doi: 10.1007/BF00434102. [PMID 9006767] [DOI] [PubMed] [Google Scholar]
- 34.Mäkinen TJ, Abolghasemian M, Watts E, Fichman SG, Kuzyk P, Safir OA, Gross AE. Management of massive acetabular bone defects in revision arthroplasty of the hip using a reconstruction cage and porous metal augment. Bone Joint. J. 2017;99(B(5)):607–613. doi: 10.1302/0301-620X.99B5.BJJ-2014-0264.R3. [PMID 28455469 DOI 10.1302/0301-620X.99B5.BJJ-2014-0264.R3] [DOI] [PubMed] [Google Scholar]
- 35.Levai JP, Boisgard S. Acetabular reconstruction in total hip revision using a bone graft substitute. Early clinical and radiographic results. Clin Orthop Relat Res. 1996 Sep;330:108–14. doi: 10.1097/00003086-199609000-00013. [PMID 8804280] [DOI] [PubMed] [Google Scholar]