Antiprotrusio Cage Research Articles

Cup and Cage Reconstruction for Metastatic Acetabular Lesions Provides Functional Improvement and Cost-efficiency

Objective: Pathologic acetabular lesions have multiple surgical options proposed and no clearly defined optimal solution at this time. In this study, we present our cage and cup reconstruction method and analyze postoperative outcomes against previously published studies. Patients and Methods: Twenty-four patients from 2014 to 2020 with acetabular pathologic lesions treated with an antiprotrusio cage and cup reconstruction were identified. Patient charts were reviewed for operative time, blood loss, Musculoskeletal Tumor Society functional scores, follow-up, and complications. Results: The average blood loss was 727 mL, and the average postoperative Musculoskeletal Tumor Society score was 70.3, with an average improvement of 35.2 points from preoperative scores. The average cost of our construct per year was $1177 for patients surviving >1 year after surgery. Eleven (45%) patients had died of disease at an average survival time of 14.2 months. Conclusion: Our study compares well with historic reconstruction strategies for metastatic acetabular disease, showing that this cup/cage reconstruction provides a durable and perioperatively safe approach that provides functional improvement while remaining cost-efficient. Level of Evidence: Level IV.

Cage Augmentation of the Retained Acetabular Shell with a Dual Mobility Cup using the Double Socket Technique

Introduction: Prevention of dislocation after total hip arthroplasty (THA) remains a topic of debate. There are various surgical options to manage hip instability such as large femoral heads, and constrained liners, although the best option to tackle this is still controversial. In revision scenarios with previous well-fixed acetabulum shells, the cementation of polyethylene liners or the cementation of dual mobility (DM) into a well-fixed acetabulum shell (Double Socket Technique) has been documented before. Here, we report a case of re-revision THA, where we have used the Double Socket Technique of retaining the previous well-fixed acetabular shell with the cementation of the DM cup along with an anti-protrusio cage inside the socket. To the best of our knowledge, this is the first such a case to be reported worldwide. Case Report: A 54-year-old male who underwent THA in 1990 and an acetabulum cup revision in 2003 presented to us with right hip pain. Radiographs showed Paprosky Type 3A femoral bone loss and polyethylene wear. Intraoperatively after removing the polyethylene liner, the acetabulum shell was found to be well fixed and therefore retained. To increase stability, an anti-protrusio cage was inserted over it and a DM cup was cemented onto it (double socket). The femoral stem was revised using Wagner stem and encerclage wires and a hook plate was used to stabilize the osteotomy site. Conclusion: This technique is a reliable option and helps shorten the surgical time and reduce the bone loss that can occur in extracting a well-fixed acetabulum shell. The use of a DM cup decreases the chances of instability compared to the cementation of polyethylene liners and decreases the high failure rate associated with the use of cementation of constrained liners. The addition of an anti-protrusio cage in addition to the Double Socket Technique increases the stability of the construct. Keywords: Anti-protrusio cage, Dual mobility, Double socket, Revision total hip arthroplasty, Well-fixed acetabulum

Treatment of Severe Acetabular Defects With an Antiprotrusio Cage and Trabecular Metal Augments - Clinical and Radiographic Results After a Mean Follow-Up of 6.6 Years

BackgroundLarge acetabular bone defects present a serious challenge in revision total hip arthroplasty. The off-label use of antiprotrusio cages in combination with tantalum augments is a promising treatment option in these difficult situations. MethodsBetween 2008 and 2013, 100 consecutive patients underwent acetabular cup revision with a cage-augment combination in Paprosky 2 and 3 defect types (including pelvic discontinuities). There were 59 patients available for follow-up. The primary endpoint was the explantation of the cage-and-augment construct. The secondary endpoint was acetabular cup revision for any reason. Also, radiographic and functional outcomes (Western Ontario and McMaster Universities Osteoarthritis Index, Harris Hip Score) were evaluated. Implant survival rates were determined using a Kaplan–Meier analysis. The significance level was set at P < .05. ResultsExplantation-free survivorship of the “Cage-and-Augment” system was 91.9% after a mean follow-up of 6.2 years (range, 0 to 12.8). All 6 explantations were due to periprosthetic joint infection (PJI). The overall revision-free implant survival rate was 85.7%, including 6 additional liner revisions due to instability. In addition, 6 early PJI occurred, which were successfully treated with debridement, irrigation, and implant retention. We did observe one patient who had radiographic loosening of the construct without necessity for treatment. ConclusionThe combination of an antiprotrusio cage with tantalum augments is a promising technique in treating large acetabular defects. A major risk of PJI and instability due to large bone and soft tissue defects needs special attention.

Hip Arthroplasty With the Use of a Reconstruction Cage and Porous Metal Augment to Treat Massive Acetabular Bone Loss: A Midterm Follow-Up.

Acetabular reconstruction in the context of massive acetabular bone loss is challenging. In rare scenarios where the extent of bone loss precludes shell placement (cup-cage), reconstruction at our center consisted of a cage combined with highly porous metal augments. This study evaluates survivorship, complications, and functional outcomes using this technique. Patients with minimum 2-year follow-up were included. Baseline characteristics were collected. Preintervention and postintervention ambulatory scores were collected. Kaplan-Meier (KM) survival analysis for cage failure requiring revision surgery was conducted. Binomial regression analysis was performed to assess for correlation of aseptic cage failure with baseline characteristics. Preintervention and postintervention ambulatory aid requirements were compared. A total of 41 patients were identified. Mean follow-up was 6.4 years (range 2.8-11.0). Four (9.8%) aseptic cage revisions were identified. Aseptic KM survival analysis was 87.4% (95% confidence interval 75.3-99.6) at 10 years. Aseptic KM survival was 45.0% versus 92.8% at 9 years (P= .14) for patients with vs without pelvic discontinuity. KM survival for all-cause failure was 61.6% (95% confidence interval 44.0-79.2) at 10 years. Binomial regression did not demonstrate correlation of cage failure with baseline characteristics. Wilcoxon signed-rank test demonstrated a significant reduction in ambulatory aide requirement after surgery (mean rank 11.47 vs 9.00, Z=-2.95, P= .003). In scenarios of massive acetabular bone loss where a cup-cage is not a viable option, good survivorship free from aseptic cage failure can be expected at mid-term follow-up using an antiprotrusio cage combined with porous metal augments. Success requires extensive experience in revision surgery.

Strategies for cup revision

Hip arthroplasty revision management can range from simple procedures using standard implants to complex surgical interventions requiring the combined use of revision cups, metal augments, bone grafts, and antiprotrusio cages. The adequate restoration of biomechanics and function of the hip joint with reconstruction of the original center of rotation can be challenging. We present an overview of various available techniques with the associated implant and anchoring strategies and the respective clinical results depending on the acetabular defect situation.

The modern Burch-Schneider antiprotrusio cage for the treatment of acetabular defects: is it still an option? A systematic review.

A number of papers have been published about the clinical performance of modern rough-blasted titanium Burch-Schneider antiprotrusio cages (BS-APCs) for the treatment of acetabular bone defects. However, no systematic review of the literature has been published to date. The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried for publications using keywords pertinent to Burch-Schneider antiprotrusio cage, revision THA, and clinical outcomes. 8 articles were found to be suitable for inclusion in the present study in which 374 cases (370 patients) had been treated with modern BS-APCs. Most acetabular bone defects were type 3 according to the Paprosky classification (type 2C: 18.1%, 3A: 51%, and 3B: 28.9%). The overall re-revision rate for the 374 acetabular reconstructions with modern BS-APCs was 11.5% (43 cases). The short-term survival rate of the modern BS-APC construct was 90.6% (339 out of 374 cases), while the mid-term survival rate was 85.6% (320 out of 374 cases), and the long-term survival rate 62% (54 out of 87 cases). The most common reasons for revision were aseptic loosening (5.6%), periprosthetic joint infection (3.8%), dislocation (2.7%), and acetabular periprosthetic fracture (1.9%). There was moderate quality evidence to show that the use of modern rough blasted titanium BS-APCs in cases of acetabular bone loss has an unacceptably high failure rate (38%). Given that antiprotrusio cages do not provide any biological fixation, we would not recommend the routine use of modern BS-APCs in complex revision THA cases. By contrast, the satisfactory short- to mid-term outcome of modern BS-APCs in combination with their low cost compared to highly porous acetabular implants, make us feel that BS-APCs might still be used in selected elderly or low-demand patients without severe superomedial acetabular bone loss.

Survival of the GAP II cage in the management of metastatic disease of the acetabulum.

The aim of this study was to assess the clinical and radiological outcomes of an antiprotrusio acetabular cage (APC) when used in the surgical treatment of periacetabular bone metastases. This retrospective cohort study using a prospectively collected database involved 56 patients who underwent acetabular reconstruction for periacetabular bone metastases or haematological malignancy using a single APC between January 2009 and 2020. The mean follow-up was 20 months (1 to 143). The primary outcome measure was implant survival. Postoperative radiographs were analyzed for loosening and failure. Patient and implant survival were assessed using a competing risk analysis. Secondary parameters included primary malignancy, oncological treatment, surgical factors, length of stay in hospital, and postoperative complications. A total of 33 patients (59%) died during the study period at a mean of 15 months postoperatively (1 to 63). No patient had radiological evidence of loosening or failure. Acetabular component survival was 100%. Three patients (5.4%) had further surgery; one (1.8%) underwent revision of the femoral component for dislocation, one required debridement with implant retention for periprosthetic joint infection, and one required closed reduction for dislocation. Using death as a competing risk, at 100 months, the probability of revision was 0.036 and the risk of death was 0.84. With appropriate patient selection, the antiprotrusio cage offers good implant survival, with a reasonable perioperative complication rate in this high-risk group of patients when managing metastatic disease or haematological malignancy around the acetabulum. Cite this article: Bone Joint J2022;104-B(4):504-509.

Bone impaction grafting and anti-protrusio cages in high-grade acetabular defects: a 22-year single centre experience.

Report clinical and radiological long-term follow-up (FU) outcome of bone impaction grafting (BIG) and anti-protrusio cage (APC) technique in hip revision surgery. We analysed data on complications, as well as the clinical and radiological outcome of patients treated using this technique at our institution. We evaluated the acetabular bone stock renovation, acetabular component stability and its radiological migration. The clinical parameters considered were the Visual Analogue Scale (VAS) and the modified Harris Hip Score (mHHS). Forty hips, with a mean 14.3-year FU, were included. This technique showed good clinical long-term results in an elderly and low-demanding population (mean age at surgery 71.4 ± 12.1years). The radiological results were not as good as clinical results: 67.5% of cases had a radiographic evidence of resorption of less than 1/3 of the bone graft; 27.5% had a resorption ranging from 1/3 and ½ of the graft, and 5% had more than ½ of the graft. Paprosky type III B reported worse results in terms of graft resorption and a greater migration of the APC (p < 0.001). The survival rate was 95% and a 2.5% rate of septic failure was recorded. Impaction grafting with femoral head and APC is an effective technique for treating high-grade acetabular defects. APC reconstructs the hip centre of rotation, avoiding loading forces on the underlying bone graft that can be correctly integrated. At long-term FU, satisfactory clinical results, not strictly correlated to radiological signs of integration, were observed; Paprosky type III B reported worse results in terms of graft resorption and a greater migration of the APC.

The use of a non-biological, bridging, antiprotrusio cage in complex revision hip arthroplasty and periacetabular reconstructive oncologic surgery. Is still today a valid option?: A mid/long-term survival and complications\u2019 analysis

IntroductionBurch–Schneider-like antiprotrusio cages (B-SlAC) still remain helpful implants to bridge severe periacetabular bone losses. The purpose of this study was to evaluate outcomes and estimate both cages’ failures and complication risks in a series of B-SlAC implanted in revision of failed total hip arthroplasties (THA) or after resection of periacetabular primary or secondary bone malignancies. Risk factors enhancing the chance of dislocations and infections were checked.Materials and methodsWe evaluated 73 patients who received a B-SlAC from January 2008 to January 2018. Group A, 40 oncological cases (22 primary tumors; 18 metastases); Group B, 33 failed THAs. We compared both Kaplan–Meier estimates of risk of failure and complication with the cumulative incidence function, taking account the competing risk of death. Cox proportional hazards model was utilized to identify possible predictors of instability and infection. Harris hip score HHS was used to record clinical outcomes.ResultsMedium follow-up was 80 months (24–137). Average final HHS was 61 (28–92), with no differences within the two groups (p > 0.05). The probabilities of failure and complications were 57% and 26%, respectively, lower in the oncologic group than in the rTHA group (p =0 .176; risk 0.43) (p = 0.52; risk 0.74). Extended ileo-femoral approach and proximal femur replacement (p =0.02, risk ratio = 3.2; p = 0.04, rr = 2.1) were two significant independent predictors for dislocations, while belonging to group B (p = 0.04, rr = 2.6) was predictable for infections.ConclusionBurch–Schneider-like antiprotrusio cages are a classical non-biological acetabular reconstruction method that surgeons should bear in mind when facing gross periacetabular bone losses, independently of their cause. However, dislocation and infection rates are high. Whenever possible, we suggest preserving the proximal femur in revision THA, and to use a less-invasive postero-lateral approach to reduce dislocation rates in non-oncologic cases.

Primary total hip replacement using Burch-Schneider cages for acetabular fractures.

Osteoporotic acetabular fractures are common and pose a difficult technical challenge for the trauma surgeon. Acute total hip arthroplasty (THA) using a Burch-Schneider antiprotrusio cage with immediate postoperative weight-bearing is a method to approach these injuries. This case series reports our outcomes of acute THA using Burch-Schneider cages for acetabular fractures from a UK major trauma centre based on length of stay, radiological outcome, complications and outcome scores. Data were collected from all patients who underwent acute THA with a Burch-Schneider cage for acetabular fractures between June 2006 and August 2015. Patients were followed up clinically, radiologically, and using Oxford Hip Scores (OHS). 20 patients with a median age of 73 (range 60-90 years) were identified. All patients were independent walkers at follow-up, and had achieved radiological union. There were no dislocations, subsidence, revision or deep infections. Significant complications include 1 perioperative death as a result of complications arising from pre-existing pulmonary fibrosis; 1 deep vein thrombosis; 1 intraoperative arterial injury to the superior gluteal artery; and 1 leg-length discrepancy. Mean length of stay was 10 days. The mean OHS was 37/48 at a mean follow-up of 26 months. This case series further validates the use of Burch-Schneider cages with primary THA in acute acetabular fractures.

Survival Analysis of Allografting and Antiprotrusio Cage in Treating Massive Acetabular Bone Defects

BackgroundMassive acetabular bone defects reconstructed with allografting and antiprotrusio cage in revision hip arthroplasty is less reported in the literature. We here report a series of 84 antiprotrusio cages and analyze the risk factors associated with failure. MethodsAll instances of use of an antiprotrusio cage for massive acetabular defect (Paprosky type IIc, III, and pelvic discontinuity) between 2002 and 2017 in the authors’ institute were reviewed after institutional review board’s approval. Survival analyses based on clinical data, bone defect (Paprosky system), type of allograft, size of cage, fixation quality, and position of cage were performed. Failure was defined as cage loosening or breakage, poor hip function, or cage revision for any reason. ResultsA total of 84 cages in 77 patients (mean age, 62.9 years), with a mean follow-up period of 6.2 years, had a survival rate of 82.1%. Failure was noted in 15 hips, including mechanical failure in 8 hips, recurrent dislocation in 1 hip, poor hip function in 1 hip, and periprosthetic joint infection in 5 hips. Pelvic discontinuity, reconstruction with morselized allograft alone, and fewer than 4 fixation points to the host bone were associated with higher failure rates (hazard ratios, 4.02, 3.42, and 9.9, respectively). ConclusionWe found that an antiprotrusio cage combined with strut allografts, fixed securely to the host bone (>4 fixation points), are beneficial for the management of massive acetabular bone defects. However, pelvic discontinuity remains a challenge that warrants the further study of technical or prosthetic innovations, such as triflange implants, cup cage, and 3D-printed implants.

Tantalum Augments Combined with Antiprotrusio Cages for Massive Acetabular Defects in Revision Arthroplasty

BackgroundTantalum components have gained popularity for the management of Paprosky type IIIA and IIIB defects during revision total hip arthroplasty. Although the use of antiprotrusio cages solely shows suboptimal results, there are certain defects that still require their use. We hypothesized that combining tantalum augments and an antiprotrusio cage would (1) improve radiographic stability, (2) enhance survivorship, (3) decrease complications, and (4) improve clinical outcomes. MethodsWe retrospectively reviewed 20 patients with Paprosky type IIIA or IIIB defects who underwent revision of the acetabular component with a highly porous tantalum augment and an antiprotrusio cage combination. Preoperative and postoperative radiographs, survivorship free from aseptic component revision, and the Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index, and Short Form-36 scores were analyzed. The mean follow-up was 2.8 years. ResultsAt the most recent follow-up, no antiprotrusio cages had migrated and all tantalum augments had radiographic evidence of osseointegration. In addition, only 2 components were revised for aseptic etiologies and only 1 was loose. Both were revised secondary to failures of the inferior flange of the antiprotrusio cage. All clinical outcome scores significantly improved postoperatively. Finally, the risk of major postoperative complications was noted to be 10%. ConclusionsIn summary, a tantalum augment combined with an antiprotrusio cage in Paprosky IIIA and IIIB defects with divergent anatomy not amenable to a hemispherical socket provides a reliable technique to restore the anatomic hip center and prevent superior migration and provides a bony ingrowth surface. Longer term follow-up is required before the technique is widely adapted. Level of EvidenceLevel IV, therapeutic studies.

Reconstruction options and outcomes for acetabular bone loss in revision hip arthroplasty.

Revision total hip arthroplasty in the setting of acetabular bone loss is a challenging procedure and requires a solid understanding of current acetabular reconstruction options. Despite major developments in the field of revision hip surgery in recent decades, reconstruction of acetabular defects remains a major problem in order to achieve primary stability and durable fixation without sacrificing additional bone stock. Although there are several ways to classify acetabular bone defects, the Paprosky classification system is the most commonly used to describe the defects and guide treatment strategy. An understanding of the bone defects associated with detailed pre-operative assessment and planning are essential elements in order to achieve satisfactory outcomes. Multiple acetabular reconstructive options are currently available including impaction bone grafting with metal mesh, reinforcement rings and antiprotrusio cage, structural allografts, cementless hemispherical cups, extra-large “jumbo cups”, oblong cups, modular porous metal augments, cup-cage constructs, custom- made triflange cups, and acetabular distraction. To date, debate continues as to which technique is most effective due to the lack of long-term studies of modern reconstruction systems. Further long-term studies are necessary to assess the longevity of the different implants. The purpose of this study was to review the current literature and provide a comprehensive understanding of the available reconstruction options with their clinical outcomes.

Surgical Treatment of Pelvic Discontinuity: A Systematic Review and Meta-Analysis.

Pelvic discontinuity is a rare condition that is treated with a range of implant constructs. However, surgical failure rates are high, and outcome data are inconsistent. It is therefore difficult to gain a clear picture of whether recently developed constructs (antiprotrusio cage [APC], cup-cage, custom triflange, and porous metal) provide better outcomes in terms of mechanical failure and complications in the short to long terms. This study investigated the failure and complication rates associated with cage constructs and porous metal technologies. A systematic review and meta-analysis were performed according to the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines to evaluate the studies showing pelvic discontinuity in revision total hip arthroplasty. Data retrieved included the intervention performed, length of follow-up, mechanical failure, and other complication rates (dislocation, infection, neurological, loosening, migration). Study quality was assessed with the Methodological Index for Non-Randomized Studies (MINORS) instrument. Pooled mechanical failure and complication rates were calculated using MetaXL 5.3. None of the included 30 articles (n = 585 hips) were of high quality. The meta-analyses revealed a mechanical failure rate of 14% for all constructs combined. Custom triflange (5%) and cup-cage (7%) had the lowest mechanical failure rates compared with the commonly used APC (25%) and porous metal (12%). The overall other complication rate was 28%, with cup-cage lower at 21% compared with APC (34%) and custom triflange (28%). Long-term evidence investigating both interventions and porous metal technology is limited. Mechanical failure rates for cup-cage and custom triflange were lowest. The other complication rate for cup-cage was lower than the pooled average. The study quality was limited, indicating a need for better studies and/or a registry. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Restoring stability in a neglected acetabular fracture with dual mobility total hip arthroplasty: a case report

&lt;p class="abstract"&gt;Neglected acetabular fractures present with varied degrees of soft tissue and bone loss and distorted anatomy resulting in high hip centres. The basic principles of achieving stability and restoring motion are to augment the acetabular bone loss, prevent protrusio in the long term and use a prosthesis that prevents dislocation. We report a case of a 22 year old neglected acetabular fracture managed successfully with a femoral head autograft, anti protrusio cage and dual mobility total hip arthroplasty.&lt;/p&gt;

Dislocation rates with combinations of anti-protrusio cages and dual mobility cups in revision cases: Are we safe?

BackgroundDue to the increasing numbers of revision total hip arthroplasty (THA) procedures being carried out, the frequency of major acetabular defects is also rising. A combination of an anti-protrusio cage and a dual mobility cup has been used in our department since 2007 in order to reduce the dislocation rate associated with complex defects. Although both implants have an important place in endoprosthetics, there are as yet limited data on the dislocation and complication rates with this combination.MethodsThis retrospective study included all patients in whom a Burch–Schneider cage and a dual mobility cup were implanted in our department between 2007 and 2014 and who had a minimum follow-up period of 24 months.ResultsThe study included 79 patients with a mean follow-up period of 5.3 years. The implant survival rate was 85% at 65 months. Postoperative dislocation occurred in two cases (2.1%), with the first dislocation taking place within the first 3 weeks in both of these patients.ConclusionsThe present study shows a promising dislocation rate with a combination of an anti-protrusio cage and a dual mobility cup. Particularly in the medium-term follow-up, no further dislocations occurred in the study. A maximum cup inclination of 45° in revision cases was associated with a lower dislocation rate in this group of patients.

Revision total hip arthroplasty with a Kerboull plate: comparative outcomes using standard versus dual mobility cups

Instability is a major complication in revision total hip arthroplasty (THA). Dual mobility (DM) cups were shown to reduce the risk of post-operative implant dislocation. Few case-series studies assessed the outcomes of cemented DM cups when associated to acetabular reconstruction antiprotrusio cages. No published comparative studies were found to look for outcome differences between standard cups (SC) and DM cups in first revision THA associated witha Kerboull plate (KP) and acetabular bone grafting. This is a retrospective comparative study of two groups of patients in two institutions. All cases were first revision THA with KP reconstruction; a cemented standard cup (SC) was used in one institution (THA-SC group) while a cemented DM cup was used in the second institution (THA-DM group). The posterolateral approach and the same technique for KP placement, the cross technique, were performed in both groups. Primary outcomes were dislocation and revision rates. Survivorship and clinical and radiological results were set to be secondary outcomes. There were ten patients (13 hips) in the first group and 16 patients (16 hips) in the second with a mean follow-up clinical and radiological evaluation of 74.2 ± 47.9months. Besides age, no significant demographic differences were present between both groups. There were three dislocations (23%) in the first group treated with close reduction compared to none in the second (p = 0.04). No further episode of dislocation or revision surgery occurred until the last follow-up in both groups. The mean Harris Hip Scores for the THA-SC and THA-DM groups were 87.5 ± 10.9 and 87.4 ± 12.1, respectively. When present, radiolucent lines were less than 1mm thick and were non-progressive in both groups. In all patients, complete trabeculation remodeling or cortical repair of the graft was observed. The cup type was the single variable which could account for the observed dislocation rate difference. The mid-term results of using DM cups with KP in first revision THA seem very encouraging. Our findings add to the previously published results on the excellent outcomes in terms of stability in revision THA when using DM cups.

Long-term results of isolated acetabular revisions with reinforcement rings: a 10- to 15-year follow-up.

The management of severe acetabular bone deficiency and a stable femoral stem can be a challenging problem in revision hip surgery. Replacement of both the acetabular and femoral component in elderly patients can increase perioperative risks without the certainty of a better functional outcome. We report the long-term outcome of reinforcement rings in isolated acetabular revision to determine whether this procedure allows hip function restoration and implant longevity. A retrospective study was conducted to evaluate the long-term results of isolated acetabular revision in thirty patients with a mean age of 70.6 years. 16 patients (16 hips) received an acetabular reinforcement ring, and 14 patients received a reconstruction cage. Acetabular defects were classified as Paprosky Type II in 16 cases and Type III in 14 cases. The mean follow-up was 11.3 years (range 10-15 years). Radiographic signs of loosening were found in 9 cases (30%). 4 cases (13.3%) with severe osteolysis and implant migration underwent further revision surgery. All 30 unrevised femoral stems were considered stable. 1 (3%) early dislocation, was conservatively treated. Clinical assessment showed a significantly improved mean Harris Hip Score from 45.1 points preoperatively to 85.4 at the latest follow-up (p < 0.05). The 15-year survival rate was 86.7%. Our long-term results showed that in selected patients, isolated acetabular revision with rings or antiprotrusio cages represents a reasonable surgical technique for the management of severe acetabular bone loss. However, concerns about the high radiographic loosening rates are possibly related to low bone ingrowth compared to new porous implants.

Reconstruction of Severe Acetabular Bone Defects in Revision Hip Arthroplasty Management options and clinical outcomes

The objective of this study was to evaluate the effectiveness of different surgical implants for the reconstruction of severe acetabular bone defects in revision arthroplasty of the hip. The current study is a retrospective study on 32 patients with Paprosky type IIIA or IIIB acetabular defects operated between January 2012-December 2015 in a single hospital. The mean follow-up was 21 months (12-43 months). Five different types of reconstruction methods were used: primary uncemented cups with or without screws, cemented acetabular cups, tantalum cups, metal augments and antiprotrusio cages. Bone allograft was available in all cases. Functional outcome after surgery was evaluated using Harris Hip Score. Based on Paprosky classification, the study included 16 type IIIA and 16 type IIIB acetabular defects. Bone graft was used in 71.8% of the cases (23 out of 32 patients). Tantalum cups were used in 15 cases (46.9%), being the preferred implant. Primary uncemented cups were used in 2 cases, cemented acetabular cups were used in 4 cases, trabecular metal augments were used in 5 cases and antiprotrusion cages were used in 6 cases. The mean Harris Hip Score improved from 37.3�7.4 pre-operatively to 82.1�7.2 at final follow-up. In conclusion, the current study demonstrates that various methods of reconstruction are efficient in the short and medium-term.

Total Hip Arthroplasty for Periacetabular Metastatic Disease. An Original Technique of Reconstruction According to the Harrington Classification

BackgroundPeriacetabular metastatic disease requires complex acetabular reconstruction. The complication rate for these frail patients is high. Various cement-rebar reinforced techniques allowing cemented total hip arthroplasty (THA) have been described. The optimal procedure has not yet been identified. MethodsA continuous series of 131 THAs performed in 126 patients with periacetabular metastatic disease was prospectively included in this study. After bone metastasis curettage and cementation, an original technique of acetabular reconstruction was performed using a dual mobility cup cemented into an acetabular reinforcement device (ie, Kerboull cross-plate or Burch-Schneider antiprotrusio cage) according to the Harrington classification. Functional outcome for independent ambulation in the community, pain relief, and occurrence of dislocation or mechanical failure of the acetabular reconstruction were assessed. ResultsAt a mean follow-up of 33 ± 17 months, the improvement in the preoperative to postoperative functional outcome and pain relief was significant (P < .001). The dislocation rate was 2%. Two of the 3 cases of dislocation occurred in acetabular reconstructions associated with a proximal femoral arthroplasty. No mechanical failure or aseptic loosening of the acetabular reconstruction was observed. ConclusionThis study emphasized that our original technique combining bone metastasis curettage and cementation, acetabular reinforcement device and cemented dual mobility cup was effective to restore a painless functional independence and ensure a durable acetabular reconstruction able to face to adjuvant radiation therapy and mechanical solicitations for long survivors. In addition, dual mobility cup limited the risk of dislocation in patients undergoing THA for periacetabular metastatic disease.