Reconstruction Of Acetabular Defects Research Articles

Management of acetabular bone defect in revision hip arthroplasty

The number of hip revision surgeries is expected to increase in recent years, and reconstruction of acetabular defects is a challenge for joint surgeons. The principle of reconstruction of acetabular defects is to achieve initial and long-term stability between the prosthesis and the host bone. With the development of surgical techniques, prosthetic materials, and revision concepts, there is an urgent need for new acetabular bone defect evaluation systems to meet clinical needs. The uncemented porous hemispherical cup has become the main prosthesis in clinical application, and metal augments are gradually replacing the structural allograft. Modular reconstruction combined cups and augments has shown favorable clinical results, which can be used for large acetabular defects with acetabular distraction technique, such as pelvic discontinuity. The advantages and disadvantages of impaction bone grafting, jumbo cups, metal augments, acetabular reinforcement rings, custom components (including custom triflanged acetabular components), and acetabular distraction technique still need to be observed in long-term follow-up.

One-stage revision for reconstructing acetabular defects by trabecular metal acetabular revision system in periprosthetic joint infection

Objective: To investigates the clinical efficacy of the trabecular metal acetabular revision system (TMARS) in one-stage reconstruction of acetabular deficiencies associated with periprosthetic joint infection (PJI). Methods: This is a retrospective case series study,including the data of 59 patients with PJI underwent acetabular defect reconstruction by TMARS during one-stage revisions in the Department of Orthopaedics, the First Affiliated Hospital of Xinjiang Medical University from January 2013 to December 2021. There were 32 males and 27 females, aged (59.5±14.6) years (range: 26 to 84 years). Among them, 29 cases used tantalum cups, 13 cases used tantalum cups and tantalum reinforcing blocks, 9 cases used cup-cage, and 8 cases used multi-cup reconstruction techniques. The surgery procedure, Harris Hip score (HHS), recovery of the hip rotation center, implant survival rate, postoperative reinfection rate, and complications were recorded. Data were compared using the Wilcoxon rank-sum test. Results: All of the 59 patients underwent the operations successfully. Operation time was (188.9±48.4) minutes (range: 110 to 340 minutes), and intraoperative bleeding volume was (M(IQR)) 1 000(400)ml (range: 600 to 1 800 ml). After a postoperative follow-up of 5.1 (2.6) years (range: 2.0 to 10.5 years), the prosthesis survival rate was 94.9% (56/59). Recurrence of infection occurred in 3 cases (5.1%), aseptic loosening in 1case(1.7%), and hip dislocation in 4 cases (6.8%). At the last follow-up, HHS improved significantly(84 (12) vs. 44 (9), Z=-6.671, P<0.01), and the center of rotation of the hips were recovered in all cases. Conclusions: In one-stage revision surgeries aimed at reconstructing acetabular defects, utilizing the TMARS can provide stable initial fixation, restore a more natural center of rotation, significantly enhance early postoperative hip joint function, and reduce the likelihood of infection recurrence. This approach stands as a reliable choice for addressing acetabular defects during revision surgeries for infected hip joints.

Bispherical metal augment improved biomechanical stability in severe acetabular deficiency reconstruction: a comparative finite element analysis

BackgroundThis study used finite element analysis (FEA) to compare the biomechanical stability of bispherical metal augment (BA) and wedge-shaped trabecular-metal augment (TA) in different acetabular defect reconstruction models, thereby explaining the application value of this novel bispherical augment in complex hip revision.MethodsThree different acetabular defect pelvis models originating from three representative patients with different types of severe acetabular defects (Paprosky IIC, IIIA, and IIIB) were constructed and reconstruction with BA and TA technique was simulated. Based on the FEA models, the displacement of reconstruction implants, relative displacement of bone implants, and hemi-pelvic von Mises stress were investigated under static loads.ResultsBA acquired smaller reconstruction system displacement, less relative displacement of bone implants, and lower pelvic von Mises stress than TA in all Paprosky IIC, IIIA, and IIIB defect reconstructions.ConclusionThe FEA results show that BA could acquire favourable biomechanical stability in severe acetabular defect reconstruction. This technique is a reliable method in complex hip revision.

Trabecular Metal Augments for Reconstruction of Acetabular Bone Defects in Revision Total Hip Replacement: Short-Term Outcomes

Abstract Background: Revision hip surgeries are increasing dramatically nowadays, and achieving hip center of rotation is challenging. Obtaining a press-fit implant and restoring the hip’s center of rotation might be difficult during the restoration of acetabular deformities during revision total hip arthroplasty (THA). Aim: The aim of the study was to evaluate the outcomes of using trabecular metal augments for reconstruction of the acetabulum in patients undergoing revision THA with short-term follow-up. Patients and Methods: This study was conducted in Benha University Hospital between April 2019 and March 2023. It is a prospective cohort study including 20 patients who are undergoing revision THA with acetabular defects. Results: The mean age of patients in this study was 59 years old. According to Paprosky classification: 45% of type 2B. The postoperative Oxford Hip Score showed marked improvement in the outcomes, the score was excellent in 55% (11 patients), good in 40% (8 patients), and fair in only 5% (1 patient) over 16 months’ mean follow-up period. Conclusion: Due to its modularity, tantalum augments are considered a valuable method in the reconstruction of acetabular defects.

3D-printed Personalized Porous Acetabular Component to Reconstruct Extensive Acetabular Bone Defects in Primary Hip Arthroplasty.

Management of extensive acetabular bone defects in total hip arthroplasty (THA) remains challenging. This study aims to investigate the feasibility and preliminary outcomes of 3D-printed personalized porous acetabular components for the reconstruction of acetabular defects in primary THA. This retrospective study involved seven patients who received 3D-printed acetabular components in primary THA between July 2018 and March 2021. Preoperatively, acetabular bone defects were evaluated by referencing the Paprosky classification. There were two "Paprosky type IIIA" defects and five "Paprosky type IIIB" defects. The acetabular components were custom-made for each patient to reconstruct the extensive acetabular defects. The hip function was assessed according to the Harris hip score (HHS). Clinical and radiographic outcomes were assessed. The average follow-up period was 40 months, ranging from 26 to 57 months. There were no patients lost to follow-up. The HHS improved from 44 (range: 33-53) before the operation to 88 (range: 79-93) at the final follow-up. Postoperative X-rays showed that the 3D-printed personalized components were properly fitted with the acetabulum. The average center of rotation (COR) discrepancy was 2.3 mm horizontally and 2.1 mm vertically, respectively. Tomosynthesis-Shimadzu metal artifact reduction technology images showed that the implant was in close contact with the host bone. Moreover, no complications were observed during the follow-up period, including loosening, dislocation, or component protrusion. The implantation of 3D-printed personalized acetabular components showed accurate reconstruction, stable mechanical support, and favorable function at short-term follow-up. This may be a viable alternative method for reconstructing extensive acetabular defects in THA.

Elevated Blood Tantalum Concentrations in Patients Following Reconstruction of Severe Acetabular Defects in Total Hip Arthroplasty Using Modular Tantalum Augments in Combination With Uncemented Tantalum Cups

IntroductionThe reconstruction of acetabular defects in total hip arthroplasty (THA) can be challenging. An option to treat uncontained acetabular defects is to use modular tantalum augments in combination with cementless press-fit cups. However, modularity is associated with an increased risk of debonding and mechanical failure. In addition, metal wear particles can be released due to micromotions at the implant interface. Clinical data on the long-term results of this treatment strategy is limited. The purposes of this study were: (1) to evaluate the clinical and radiological outcome of complex THA using modular trabecular metal augments and uncemented revision cups; (2) to investigate the blood tantalum concentrations in these patients at mid-term (mean 4.5 year) follow-up; and (3) to report complications and mechanisms of failure related to this procedure. Materials and MethodsIn this single-center study, we retrospectively reviewed data from a consecutive cohort of 27 patients who underwent complex acetabular defect reconstruction using a modular tantalum acetabular augment in combination with an uncemented tantalum cup. We evaluated the implant survival, and the radiological and clinical outcomes after a mean follow-up of 4.5 years (SD 2.1; range 2.5 to 10.6 years) using patient-reported outcome scores (PROMs). Blood samples were analyzed regarding tantalum concentration and compared with a control group. ResultsThe cumulative survival rate at 4.5 years with the endpoint “revision of the acetabular component for aseptic loosening” was 94.4% (95% confidence interval (CI) 71.6 to 99.2) and 82.9% (95 % CI 60.5 to 93.3) for the endpoint “revision for any reason.” The PROMs improved significantly up to the latest follow-up, and radiographic data showed no signs of loosening or implant migration. Median blood tantalum concentrations were significantly higher in the study group (0.15 μg/L) compared to the control group (0.002 μg/L) (P < 0.001). ConclusionsThis study demonstrated acceptable clinical and radiological results of cementless revision THA using modular trabecular metal implants for the reconstruction of large acetabular defects. Tantalum concentrations were significantly higher in patients who had tantalum implants compared to the control group, however, the systemic and local effects of an increased tantalum exposure are not yet fully understood and have to be further investigated.

Custom triflange acetabular components for large acetabular defect reconstruction in revision total hip arthroplasty: a systematic review and meta-analysis on 1218 patients.

This is a systematic review and meta(regression) analysis to assess the performance of custom triflange acetabular components (CTAC) in total hip arthroplasty (THA) revision surgery. Implant-related complications, failure rate, functional outcomes and implant and surgical technique-related predictors for outcome were assessed. This systematic review was performed according to PRISMA guidelines and registered with PROSPERO (2020 CRD42020209700). PubMed, Embase, Web of Science, COCHRANE Library and Emcare were searched. Studies on Paprosky type 3A and 3B or AAOS type 3 and 4 acetabular defects with a minimum follow-up of 12 months and cohorts > 10 patients were included. Thirty-three studies were eligible for inclusion (n = 1235 hips, 1218 patients). The methodological quality of the studies was moderate (AQUILA: 7.4/11 points). Considerable heterogeneity was observed in terms of complications, re-operations and implant failure reporting. The total incidence of implant-related complications was 24%. The incidence of re-operation for any reason was 15%, and the implant failure rate was 12% at a mean of 46.9 months and the post-operative Harris Hip Score improved by a mean of 40 points. Several predictors for outcome were found, such as implant generation, follow-up length and study start date. The use of CTAC in revision THA has satisfactory complication and implant failure rates. The CTAC technique improves post-operative clinical outcomes and the meta-regression analysis showed that there is a clear association between improvements in the CTAC performance and the evolvement of this technique over time.

Cementless augmented versus cemented Dual Mobility cups: medium-term outcome of case series with a control group

BackgroundPost-operative dislocation and reconstruction of acetabular defects are two challenging topics in revision Total Hip Arthroplasty (rTHA). Cemented Dual Mobility (DM) cups on top of Kerboull Cross and bone graft have been successfully employed to overcome these challenges. The cementless augmented DM cups were recently introduced. In this study medium term results of the augmented cementless DM Coptos cups are reported and compared to the established technique of cemented DM cups and Kerboull plate.Material and methodsThis is a retrospective analysis of data collected on patients who received rTHA using DM cups in the period between June 2015 and September 2020. Two groups of patients were identified. The first group received cementless augmented DM-cups (NOVAE® Coptos TH–SERF) (Coptos TH cup group). The second comparable group who had Kerboull ring (KE ring group) and cemented DM cups (NOVAE® STICK). Demographic data, surgical technique, functional and radiological outcome as well as complications during the follow-up visits are reported.ResultsForty-two patients with a mean age at the time of revision 48.8 ± 13.6 years. 29 patients received Coptos TH DM-cup, while 13 patients had Bone Graft (BG), KE ring and cemented DM cups for acetabular reconstruction. Acetabular defects were Paprosky types IIB and IIC in 31 patients and IIIA and B in 11 patients. The follow-up was 52.8 ± 21 months (mean ± STD); and the mean Harris Hip Score (HHS) at last visit was 91 ± 5. Good stability of all cups was reported. Full integration of the impaction graft was observed in 94% of the Coptos and 92% of the KE groups. One of the Coptos cups was readjusted and one case of single dislocation was recorded in the KE group. None of the DM cups in both groups was revised or awaiting revision.ConclusionCoptos TH cups achieve similar results to the cemented DM on KE ring at the medium term but long term outcome remains to be seen.

Impaction Bone Grafting with Low Dose Irradiated Freeze-Dried Allograft Bone for Acetabular Reconstruction.

ObjectiveReconstruction of acetabular defects has been extremely challenging in both primary and revision total hip arthroplasty (THA). Impaction bone grafting (IBG) can restore the acetabulum bone mass and anatomically reconstruct the acetabulum. Our study aimed to report the short and medium‐term clinical and radiographic outcomes of IBG for acetabular reconstruction in the cemented THA in the Chinese population.MethodsThis was a single‐center retrospective review enrolling 57 patients between May 2013 and July 2019. The patients with acetabular defects were treated with IBG, using low dose irradiated freeze‐dried allograft bone with or without autograft bone, in the cemented THA performed by one senior surgeon. Harris hip score (HHS), standard pelvis anterior–posterior radiograph and lateral hip radiograph were obtained before operation and at 1 week, 3 months, 12 months, and yearly. Graft osteointegration was evaluated by Oswestry's criteria, and complication was documented at the last follow‐up. Independent sample ANOVA test and Pearson chi‐square tests are used for statistical analysis.ResultsThere were 61 hips in 57 patients. The average follow‐up time was 35.59 months (5–77 months). According to AAOS classification, a total of 18 hips were identified as segmental bone deficiency (type I), with 21 and 22 hips for cavitary bone deficiency (type II) and the combined bone deficiency (type III), respectively. The average HHS was improved from 44.49 (range: 32–58) preoperatively to 86.98 (range: 78–93) postoperatively. Graft osteointegration was satisfactory (Oswestry score ≥2) in all patients. No dislocation occurred in the 57 patients (61 hips) during follow‐up. Although one cup migrated, no revision, re‐revision, radiographic loosening, graft bone lysis, or postoperative complications were detected at the final follow‐up.ConclusionsIBG with low‐dose irradiated freeze‐dried allograft bone in acetabular bone defect reconstruction is a reliable technique for restoring acetabular bone defects in THA.

Feasibility and preliminary efficacy of tantalum components in the management of acetabular reconstruction following periacetabular oncologic resection in primary malignancies

BackgroundThe aim of the study was to investigate the feasibility and preliminary efficacy of tantalum components utility in the reconstruction of acetabular defects following periacetabular oncologic resection of primary malignancies.MethodsWe prospectively collected a consecutive of 15 cases that were treated with tantalum components for acetabular reconstruction after periacetabular oncologic resection from January 2018 to December 2018. The cohort included 8 male and 7 female patients, with a mean age of 47.6 years (range, 33 to 67 years). Pathology types: chondrosarcoma (n = 9), malignant bone giant cell tumor (n = 3) and osteosarcoma (n = 3). Clinical outcomes, functional and radiographic results were recorded in detail for analysis.ResultsPatients received planned oncologic resection and tantalum components reconstruction without casualty; they were followed up with a mean of 39.7 months (35–45 months). The mean operation time was 4.0 h (3.0–6.0 h), and the mean blood loss was 1260 ml (800–2200 ml). Functional outcomes were assessed by MSTS-93 scale, with an average of 21.8 (12.0–26.0 scores), among which 3 cases were excellent, 11 were good and 1 was fair. The mean Harris Hip Score was 79.1scores (46.0–92.0 scores) at 1-year follow-up postoperatively. 3(3/15, 20.0%) cases experienced postoperative complications: 2 cases with hip dislocation received closed reduction under general anesthesia and were fixed with hip joint abduction braces for 6 weeks; one case had a superficial infection and received debridement with a delayed wound healing. Oncologic prognosis: one case relapsed at 8-month follow-up and received hemi-pelvic amputation; and another osteosarcoma patient experienced relapse with pulmonary metastasis and received further chemotherapy. No prosthetic loosening, displacement or fracture occurred during the follow-up period.ConclusionPreliminary results suggested that the use of tantalum components in the management of acetabular reconstruction following periacetabular oncologic resection provided reasonable improvement on functional outcomes and early stability of the prostheses. Porous tantalum components are conducive to bony ingrowth, which is a potential alternative to various existing reconstruction techniques to achieve better functional outcomes.

Revision Total Hip Arthroplasty with Severe Acetabular Defect: A Preliminary Exploration and Attempt of Robotic‐Assisted Technology

BackgroundRobotic‐assisted technology may be useful in hip revision cases with acetabular defects. However, data on the use of robotic‐assisted technology for such complex diseases is lacking.Case PresentationThis case study described the adoption of MAKO robotic‐assisted treatment of revision total hip arthroplasty (THA) combined with severe acetabular defect (Paprosky type IIIB). Robotic‐assisted technology accurately achieved preoperative planning; the acetabular component and augment were placed in the original position and angle as planned. Robotic‐assisted acetabular reaming was successful in a single pass, preserving the remaining acetabular bone mass very well with no procedure‐related complications. The Harris Hip Score (HHS) at 6 months postoperatively was 84 and the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index was 24.ConclusionRobotic‐assisted technology can help in the accurate reconstruction of acetabular defect in complex hip revision surgery.

Porous tantalum shell and augment for acetabular defect reconstruction in revision total hip arthroplasty: a mid-term follow-up study.

The use of porous tantalum trabecular metal (TM) shell and augment to reconstruct acetabular defects in revision total hip arthroplasty (THA) is a reliable technique. We evaluated the mid-term implant survival, clinical, and radiological outcomes of our first 48 revisions using this technique. A total of 45 patients (48 hips) who had acetabular revision of THA between 2011 and 2017 using TM shell and augment with possible mid-term follow-up were included. Twenty-two patients were men (49%) and 23 were women (51%), mean age was 62.5years (34 to 85) and mean follow-up was 75months (54 to 125). Twenty-four hips (50%) had a Paprosky IIIA defect, 14 (29.2%) had a type IIIB defect, six (12.5%) had a type IIC defect, and four hips (8.3%) had a type IIB defect. None of the patients had pelvic discontinuity (PD). At a mean 6.25years follow-up, all hips remained well-fixed and implant survival of 100% with the need of re-revision as the end point. Screw fixation was used for all shells; augments and the shell-augment interface was cemented. Excellent pain relief (mean WOMAC score pain 90.5, (38.3 to 100)), and functional outcomes (mean WOMAC function 88.3 (31.9 to 100), mean OHS 89.2 (31.8 to 100)) were noted. Patient satisfaction scores were excellent. This study demonstrated satisfactory mid-term clinical and radiological outcomes of using TM shell and augment for reconstructing major acetabular defects without PD in revision THA.

THA in patients with neglected acetabular fractures.

Introduction: Total hip arthroplasty (THA) outcomes in patients with neglected acetabular fractures are less favourable compared to THA for osteoarthritis or inflammatory arthritis. These poorer clinical outcomes are largely due to an unexpected bone deficiency, and the procedure is more time-consuming and complicated for cases that require acetabular reconstruction and bone grafting. The clinical outcomes of THA in neglected acetabular fractures are not often studied. Methods: This study is a retrospective single surgeon series of THA for 51 neglected acetabular fractures in 49 patients treated with THA alone, open reduction and internal fixation with THA, or acetabular defect reconstruction THA. Our series aims to focus on the surgical technique and describe the functional and radiological outcomes of neglected acetabular fractures treated with different THA approaches by a single surgeon. Results: Using the Harris Hip score at the mean long-term follow-up, there was a clear improvement in 90% of patients in the present study. The long-term results are encouraging in terms of clinical improvement, radiographic restoration of acetabular bone stock, and the centre of restoration. Discussion: The series shows that with proper planning and reconstruction using structural bone grafting techniques, a neglected fracture-dislocation with loss of structural support can be satisfactorily treated using primary components alone. Bony reconstruction and use of primary cementless components ensure long-term survival and preserve bone stock for an easier revision of THA, if necessary, in the future.

Minimum 10\u2009years clinical and radiological outcomes of acetabular revisions of total hip arthroplasties with tricalcium phosphate/hydroxyapatite bone graft substitute

BackgroundAseptic loosening is the most frequent indication for revision of total hip arthroplasty. Revision arthroplasty of acetabular component is a challenge for every surgeon because they have to simultaneously deal with the reconstruction of bone defects, adequate implant geometry and stable fixation. Allografts are the most frequently used materials in reconstruction of bone loss during revision surgeries. Because of an increasing number of revision hip arthroplasties and poor availability of allografts, we decided to use bone graft substitutes in acetabular revisions.MethodsBetween September 2005 and January 2010, 44 revision arthroplasties in 43 patients were performed with the use of bone graft substitutes for acetabular defect reconstruction in revision of total hip arthroplasty. Acetabular bone defects were classified according to Paprosky. Seventeen hips were classified as IIA, 3 hips IIB, 3 hips IIC, 10 hips IIIA and 11 hips IIIB. Acetabular bone defects were reconstructed with tricalcium phosphate/hydroxyapatite bone graft substitute - BoneSave. Clinical and radiological examination was performed after 3 months, 1 year and then annually. Harris hip score was used for clinical evaluation. Survival analysis was performed with Kaplan-Meier method with aseptic loosening as the definition of endpoint.ResultsThe average follow-up period is 12 (range from 10 to 15) years. During the follow-up, three patients died after 24 months because of causes not related to surgery. None of the patients was lost to follow-up. The evaluation of clinical results revealed an increase in pre-operative HHS from average 38.3 (range 25 to 55) points to average 86.3 (range 45 to 95) points at the most recent follow-up. Radiographic evaluation showed the migration of one revision cage 12 months after surgery. Revision arthroplasty performed after 14 months revealed the partial incorporation of bone graft substitute. There were not any cases of loosening of revision acetabular cup at the most recent follow up examination in the remaining 39 patients. Bone graft substitute was not absorbed in all of these patients. The survival after 10 years amounted to 97.56%.ConclusionBone graft substitute Bone Save may be suitable for acetabular revision surgery, however preoperative bone defect is critical for success and determining of a surgical technique, so this is multifactorial in this challenge surgery.

Reconstruction of acetabular defects greater than Paprosky type 3B: the importance of functional imaging

Background3D Surgical planning has become a key tool in complex hip revision surgery. The restoration of centre of rotation (CoR) of the hips and leg length (LL) are key factors in achieving good clinical outcome. Pelvic imaging is the gold standard for planning and assessment of LL. We aimed to better understand if 3D planning is effective at equalising LL when large acetabular defects are present.Materials and methodsThis was a prospective case study of 25 patients. We report the analysis of pre-operative LL status and planned LL restoration measured on CT, in relation to the achieved LL measured post-operatively in functional, weight bearing position. Our primary objective was the assessment of restoration of CoR as well as the anatomical and functional LL using biplanar full-length standing low-dose radiographs; our secondary objective was to evaluate the clinical outcome.ResultsPre-operative intra-pelvic discrepancy between right and left leg was a mean of 28 mm (SD 17.99, min = 3, max = 60 mm). Post-operatively, the difference between right and left vertical femoral offset (VFO), or CoR discrepancy, was of 7.4 mm on average, significantly different from the functional LL discrepancy (median = 15 mm), p = 0.0024. Anatomical LLD was a median of 15 mm. In one case there was transient foot drop, one dislocation occurred 6 months post-operatively and was treated by closed reduction, none of the patients had had revision surgery at the time of writing. Mean oxford hip score at latest follow up was 32.1/48.DiscussionThis is the first study to investigate limb length discrepancy in functional position after reconstruction of large acetabular defects. We observed that VFO is not an optimal surrogate for LL when there is significant bone loss leading to length inequality, fixed flexion of the knee and abduction deformity.ConclusionsAlthough challenging, LLD and gait abnormalities can be greatly improved with the aid of an accurate surgical planning. Surgeons and engineers should consider the integration of EOS imaging in surgical planning of reconstruction of large acetabular defects.

Reconstruction of Acetabular Defects With Impaction Grafting in Primary Cemented Total Hip Arthroplasty Produces Favorable Results: Clinical and Radiographic Outcomes Over 6.4 Years on Average

BackgroundCemented primary total hip arthroplasty (THA) associated with acetabular reconstruction (AR) involving impacted bone grafting has been employed successfully in the revision of cavitary defects but the results are reportedly less predictable for segmental defects. The objective of the study is to evaluate the clinical and radiographic results of patients who had presented cavitary, segmental, and combined acetabular defects and received THA/AR involving impacted morselized cancellous bone autografts followed by rigorous postoperative management. MethodsClinical outcomes were assessed retrospectively of 154 patients who had been submitted to 169 THA/AR procedures performed by a single surgeon over a 15-year period. The Harris Hip Score system was applied to 103 patients, and the degree of acetabular migration was determined from radiograph images of 91 AR procedures, of which 40 were segmental/combined and 51 were cavitary reconstructions. ResultsThe frequency of aseptic acetabular loosening was 3% while that of thromboembolic events was 4.1%. According to Harris Hip Score, 87.4% of outcomes were classified as excellent/good after an average follow-up period of 6.4 years irrespective of the type of acetabular defect. Horizontal and/or vertical acetabular migrations and changes in angular tilt were observed in all ARs, although the minor movements detected did not undermine the structural stability of the reconstructions or the functional capacity of patients. ConclusionThe described THA/AR technique can be used effectively in the reconstruction of segmental/combined and cavitary acetabular defects. The success of the technique as applied to segmental/combined defects was attributed in part to the rigorous rehabilitation protocol with temporary postoperative weight-bearing restriction.

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.

Bone integration in acetabular revision hip arthroplasty using equine-derived bone grafts: a retrospective study.

During the last decade, total hip arthroplasty has become a common procedure performed in young patients, as well as elderly ones. This has led to an increase in total hip arthroplasty revisions. Loosening of primary components with associated bone loss represents the major cause of total hip arthroplasty revision. This study evaluates the safety and performance of an enzyme-deantigenic equine-derived bone graft material in acetabular defect reconstruction. Records of 55 patients who were treated for Paprosky type II or III acetabular bone defects with arthroplasty revisions using equine-derived bone and followed for an average of 34months (range from 24 to 48months) were analyzed. Of the 55 revisions, 49 (89%) were regarded as successful, showing good osteointegration without signs of mobilization. Failures included six cases (11%) of mobilization: five cases of aseptic mobilization (9.1% of revisions, 83% of failures) and one case of septic mobilization (1.9% of revisions, 17% of failures). These results are consistent with those of studies having a similar follow-up period for allografts used in combination with trabecular metal components. Results of the present study suggest that enzyme-treated equine-derived bone grafts may be a valid alternative to autogenous and homologous bone grafts in total hip arthroplasty revision.

Enhancing biology and providing structural support for acetabular reconstruction in single-stage revision for infection

BackgroundReconstruction of combined segmental and cavitary defects of the acetabulum is a challenge to the hip surgeon. One question regards the efficacy of reconstruction of acetabular defects using a combination of tantalum metal augments (TMAs) and impaction graft in single-stage revision for periprosthetic infection.Materials and methodsIn the period between July 2009 and August 2014, 24 patients with combined segmental and cavitary acetabular defects and Paprosky classification grade IIB, IIC, and IIIA had hips reconstructed using the combination of TMAs and antibiotic-loaded impaction grafting. A similar group of 30 patients who received single-stage revision without metal augments were identified and taken as control. All patients received a polyethylene cemented cup and long cementless (Wagner SL) stem. Patients were prospectively evaluated using the modified Harris Hip Score (HHS) in addition to radiological evaluation at 3, 6, and 12 months then annually thereafter.ResultsAt an average follow-up period of 4 years (range 2–7 years), all but one patient in the study group were free of infection, indicating a 96% success rate. This rate of eradicating infection was comparable to the 97% success rate in the control group. All metal augments were stable, and good incorporation of the impacted bone graft was observed. The HHS improved significantly from 27 preoperatively to 83 postoperatively (P < 0.001).ConclusionMetal augments can convert massive acetabular defects to a more contained defect suitable for grafting. The combination of tantalum augments that provide strong structural support and antibiotic-loaded allograft is successful in the mid-term in single-stage revisions for infection.Level of evidenceLevel IV (prospective case series).

Titanium cage reconstruction of acetabular defects in revision hip arthroplasty results in favourable outcomes: up to 17 years follow-up.

Titanium cages are valuable implant solutions in management of severe acetabular defects during total hip revisions. We aimed to report clinical and radiological results of our cases in which we used titanium cages for reconstruction of acetabular defects. Patients underwent titanium cage reconstruction and bone grafting for their acetabular defects with minimum 2 year-follow-up are included to the study. Analysis of patient records, modified Hospital for Special Surgery hip score and radiological examinations on plain X-rays were evaluated. Acetabular defects are classified according to Paprosky's classification.Kaplan Meier survival analysis is performed. Fifty-six hips of 54 patients (2 bilateral) aged between 29-79 (mean 57 years ) are followed up for 7.06 years ±3.72 (2-17 years).Five patients required revision surgeries at a mean of 2.6±2.2 years. Kaplan Meier's analysis revealed a survival rate of 91,5 % and mean revision free duration was 15,66±0,56 years.HSS scores of the patients before revision surgery yielded a mean score of 27,9 ± 4,9 (14-38). HSS scores at final follow up showed a significant improvement at a mean score of 45,9 ± 7 (28-56) differences were statistically significant, p<0,001). Titanium cages are successful for restoring bone stock in severe acetabular defects. It is critical to pay attention on meticulous bone grafting of the presented defects and obtain good hip mechanics during cage insertion. Mechanical reasons are the leading cause of failure in long term but restoration of the bone stock and improvement in defect severity were regularly observed even in failed cages.