Midterm Outcomes After Reconstruction of Superolateral Acetabular Defects Using Flying Buttress Porous Tantalum Augments During Revision Total Hip Arthroplasty

Acetabular Augments Used in Revision Hip Arthroplasty: Minimum 10-year Follow-Up of Implant Survivorships, Functional Scores, and Radiographic Outcomes

BACKGROUND

Acetabular bone loss is a major challenge in the setting of revision total hip arthroplasty (THA). Porous tantalum augments have emerged as a viable solution to acetabular bone loss in revision THA. The purpose of this study was to evaluate the survivorship, clinical, and radiological outcomes of these implants.

METHODS

We identified 104 augment implants from our retrospective chart review of revision THA from June 2003 to July 2013. Of these patients, 75 (72.1%) were women, the mean age at surgery was 66 years (range, 27 to 87), and the mean follow-up was 13.2 years (range, 0.25 to 18.2). Kaplan-Meier survival analysis was performed, with failure defined as revision for aseptic loosening of the acetabular reconstruction.

RESULTS

There was significant improvement in the Harris Hip Score from 40.0 to 77.3 (P < 0.001) and the Oxford Hip Score from 14.9 to 36.3 (P < 0.001). Survivorship for failure due to aseptic loosening was 98.8% (95% CI [confidence interval] 96.4 to 100) at 24 months with 60 hips at risk, and 90.4% (95% CI 83.0 to 97.8) at 60 and 120 months with 38 and 18 hips at risk, respectively. The overall number of complications was 34 (32.7%). Of these complications, 21 (20.2%) required repeat revision surgery. The revision rate due to aseptic loosening of the augment, infection, dislocation, aseptic loosening of the femoral component, reconstruction failure, and heterotopic ossification was seven (6.7%), five (4.8%), four (3.8%), two (1.9%), two (1.9%), and one (0.96%), respectively.

CONCLUSIONS

Treatment of acetabular defects during revision THA using porous tantalum augments provides acceptable implant survivorship and favorable clinical outcomes at mid-term (5 to 10 years) and long-term (> 10 years) follow-up.

Progress in the Application of Porous Tantalum Metal in Hip Joint Surgery

Porous tantalum metal is a new orthopedic implant material made of tantalum metal that has been processed by porous treatment. This material has various advantages, including high hardness, good ductility, good biocompatibility, and strong bone integration ability. Porous tantalum metal has performed well in clinical application, demonstrating excellent medium- to long-term curative effects. The use of implant products made of porous tantalum metal, such as porous tantalum rods, porous tantalum hip prostheses, and porous tantalum augments (MAs), is gradually increasing in the clinical application of hip surgery, and these products have achieved excellent therapeutic effects in the middle and late stages of various hip diseases. In recent years, the combined application of porous tantalum metal and three-dimenional (3D) printing technology to create personalized 3D-printed porous tantalum metal has led to new development directions for the treatment of complex hip joint surgical diseases. This review presents a summary of the application of porous tantalum metal in hip surgery in recent years, including clinical treatment effects and existing problems. In addition, the prospect of progress in this field is promoted.

Trabecular Metal Augments During Complex Primary Total Hip Arthroplasty

Background

Trabecular metal augments (TMAs) have been extensively used in revision total hip arthroplasty (THA) to address acetabular bone defects. However, limited data exists regarding TMA utilization during primary THA. This study aims to assess the clinical and radiographic outcomes of TMAs used during primary THA.

Methods

A single-institution retrospective case series of primary THA patients treated with TMA between 2010 and 2019 was performed. Patient demographics, complications, and revisions were recorded. Cup position, center of rotation, leg length, and radiolucent lines were assessed radiographically. The Kaplan-Meier method was used to compute implant survivorship.

Results

Twenty-six patients (30 hips) were included with average age of 52.6 ± 15.3 years (range: 22-78) and mean follow-up of 4.1 ± 2.1 years (range: 2.0-8.9). Most TMAs were indicated for developmental dysplasia of the hip (n = 18; 60.0%). On average, hip center of rotation was lowered 1.5 ± 1.3 cm and lateralized 1.2 ± 1.5 cm, while leg length and global offset were increased by 2.4 ± 1.2 cm and 0.4 ± 1.0 cm, respectively. At final follow-up, 3 hips (10.0%) required revision: one (3.3%) for aseptic loosening and 2 (6.7%) for instability. No patients had progressive radiolucent lines at final follow-up. Five-year survival with aseptic loosening and all-cause revision as endpoints was 100% (95% confidence interval: 90.0%-100.0%) and 92.1% (95% confidence interval: 81.3%-100.0%), respectively. One patient required revision for aseptic loosening after the 5-year mark.

Conclusions

Trabecular metal augmentation during primary THA demonstrates satisfactory early to mid-term outcomes. TMA is a viable option for complex primary THA when bone loss is encountered or secondary support is required.

Level of Evidence

Level IV.

Porous Tantalum Acetabular Cups in Primary and Revision Total Hip Arthroplasty: What Has Been the Experience So Far?-A Systematic Literature Review

BACKGROUND

The global population, especially in the Western world, is constantly aging and the need for total hip arthroplasties has rocketed, hence there has been a notable increase in revision total hip arthroplasty cases. As time has passed, a considerable developments in science and medicine have been attained which have also resulted in the evolution of both surgical techniques and implants. Continuous improvements have allowed large bore bearings to be utilized which provide an increased range of motion, with ameliorated stability and a very low rate of wear. The trend for almost the last two decades has been the employment of porous tantalum acetabular cups. Several studies exist comparing them with other conventional methods for total hip arthroplasties, exhibiting promising short and midterm results.

METHODS

The Preferred Reporting Items for Systematic Reviews and a Meta-Analysis (PRISMA) were used to identify published studies in a comprehensive search up to February 2023, and these studies were reviewed by the authors of the article. Specific rigorous pre-determined inclusion and exclusion criteria were implemented.

RESULTS

Fifty-one studies met our inclusion criteria and were involved in the systematic review. Sixteen studies examined postoperative clinical and radiological outcomes of using a tantalum cup in primary and revision total hip arthroplasty, whilst four biomechanical studies proved the superiority of tantalum acetabular components. Five articles provided a thorough comparison between tantalum and titanium acetabular cups, while the other studies analyzed long-terms results and complication rates.

CONCLUSIONS

Porous tantalum acetabular cups appear to be a valuable option in revision total hip arthroplasty, providing clinical improvement, radiological stability, and promising long-term outcomes. However, ongoing research, longer follow-up periods, and careful consideration of patient factors are essential to further validate and refine the use of tantalum in various clinical scenarios.

How modular porous metal augments have changed the management of acetabular bone loss at primary or revision total hip arthroplasty

The advent of modular porous metal augments has ushered in a new form of treatment for acetabular bone loss. The function of an augment can be seen as reducing the size of a defect or reconstituting the anterosuperior/posteroinferior columns and/or allowing supplementary fixation. Depending on the function of the augment, the surgeon can decide on the sequence of introduction of the hemispherical shell, before or after the augment. Augments should always, however, be used with cement to form a unit with the acetabular component. Given their versatility, augments also allow the use of a hemispherical shell in a position that restores the centre of rotation and biomechanics of the hip. Progressive shedding or the appearance of metal debris is a particular finding with augments and, with other radiological signs of failure, should be recognized on serial radiographs. Mid- to long-term outcomes in studies reporting the use of augments with hemispherical shells in revision total hip arthroplasty have shown rates of survival of > 90%. However, a higher risk of failure has been reported when augments have been used for patients with chronic pelvic discontinuity.

Does Using Highly Porous Tantalum in Revision Total Hip Arthroplasty Reduce the Rate of Periprosthetic Joint Infection? A Systematic Review and Meta-Analysis

BACKGROUND

Studies suggest tantalum (Ta) implants may have inherent antibacterial properties. However, there is no consensus regarding the effectiveness of Ta in preventing periprosthetic joint infection (PJI) after revision total hip arthroplasty (rTHA).

METHODS

We searched 5 main databases for articles reporting the rate of PJI following rTHA using Ta implants from inception to February 2022. The PJI rates of the Ta group were meta-analyzed, compared with the control group, and represented as relative risks (RRs) in forest plots.

RESULTS

We identified 67 eligible studies (28,414 joints) for assessing the prevalence of PJI following rTHA using Ta implants. Among these studies, only 9 compared the Ta implant group with a control group. The overall PJI rate following rTHA using Ta implants was 2.9% (95% confidence interval [CI]: 2.2%-3.8%), while it was 5.7% (95% CI = 4.1%-7.8%) if only septic revisions were considered. Comparing the Ta and control groups showed a significantly lower PJI rate following all-cause rTHA with an RR = 0.80 (95% CI = 0.65-0.98, P < .05). There was a trend toward lower reinfection rates in the Ta group after rTHA in septic cases, although the difference was not statistically significant (RR = 0.75, 95% CI = 0.44-1.29, P = .30).

CONCLUSIONS

Ta implants are associated with a lower PJI rate following all-cause rTHA but not after septic causes. Despite positive results, the clinical significance of Ta still remains unclear since the PJI rate was only reduced by 20%.

LEVEL OF EVIDENCE

IV.

Biomechanical analysis and clinical observation of 3D-printed acetabular prosthesis for the acetabular reconstruction of total hip arthroplasty in Crowe III hip dysplasia

Objective: This study aimed to evaluate the biomechanical effectiveness of 3D-printed integrated acetabular prosthesis (IAP) and modular acetabular prosthesis (MAP) in reconstructing the acetabulum for patients with Crowe III developmental dysplasia of the hip (DDH). The results of this study can provide a theoretical foundation for the treatment of Crowe III DDH in total hip arthroplasty (THA). Methods: Finite element (FE) analysis models were created to reconstruct Crowe III DDH acetabular defects using IAP and MAP. The contact stress and relative micromotion between the acetabular prosthesis and the host bone were analyzed by gradually loading in three increments (210 N, 2100 N, and 4200 N). In addition, five patients with Crowe III DDH who underwent IAP acetabular reconstruction were observed. Results: At the same load, the peak values of IAP contact stress and relative micromotion were lower than those of MAP acetabular reconstruction. Under jogging load, the MAP metal augment's peak stress exceeded porous tantalum yield strength, and the risk of prosthesis fracture was higher. The peak stress in the bone interface in contact with the MAP during walking and jogging was higher than that in the cancellous bone, while that of IAP was higher than that of the cancellous bone only under jogging load, so the risk of MAP cancellous bone failure was greater. Under jogging load, the relative micromotion of the MAP reconstruction acetabular implant was 45.2 μm, which was not conducive to bone growth, while under three different loads, the relative micromotion of the IAP acetabular implant was 1.5-11.2 μm, all <40 μm, which was beneficial to bone growth. Five patients with IAP acetabular reconstruction were followed up for 11.8 ± 3.4 months, and the Harris score of the last follow-up was 85.4 ± 5.5. The imaging results showed good stability of all prostheses with no adverse conditions observed. Conclusion: Compared with acetabular reconstruction with MAP, IAP has a lower risk of loosening and fracture, as well as a better long-term stability. The application of IAP is an ideal acetabular reconstruction method for Crowe III DDH.

Standardized 3D-printed trabecular titanium augment and cup for acetabular bone defects in revision hip arthroplasty: a mid-term follow-up study

BACKGROUND

The aim of this study was to assess the feasibility and outcomes of standardized three-dimensional (3D)-printed trabecular titanium (TT) cups and augments to reconstruct most acetabular defects.

METHODS

We included 58 patients with Paprosky type II and III acetabular bone defects who underwent revision hip arthroplasty between 2015 and 2018. Patients who were revised without 3D-printed augments, and cases who were lost to follow-up and died during follow-up were excluded. Radiographic and clinical outcomes were evaluated. A Kaplan-Meier survivorship curve was generated. The mean follow-up was 64.5 (range 49-84) months.

RESULTS

In total, 48 (82.8%) acetabular revisions were performed using standardized 3D-printed TT cups and augments, and a retrospective review was conducted on 43 revisions. The average position of the vertical center of rotation and leg length discrepancy were significantly decreased from 42.4 ± 9.1 mm and 38.4 ± 10.7 mm to 22.8 ± 3.4 mm and 4.1 ± 3.0 mm, respectively. Non-progressive radiolucent lines were observed in 3 (7.5%) acetabular components with no indications for revision. The mean Harris hip score, Oxford hip score and EuroQol five-dimensional questionnaire score increased from 33.0 ± 10.7, 11.4 ± 3.4 and 0.29 ± 0.09 to 80.3 ± 8.8, 35.8 ± 2.4 and 0.71 ± 0.10, respectively. The revision-free survival rate of the acetabular component was 93.0% (40/43), with a rate of revision for aseptic loosening of 2.3% (1/43).

CONCLUSION

Standardized 3D‑printed TT augments and cups could be used to reconstruct the majority of Paprosky type II and III acetabular defects in revision hip arthroplasty and demonstrated encouraging results at mid-term follow-up.

Metal Augments Used in Revision Hip Arthroplasty: A Systematic Review and Single-Arm Meta-Analysis

BACKGROUND

Porous metal augments are used in complex hip arthroplasty; however, few studies have assessed their efficacy and safety. This systematic review analyzed the use of augments in revision hip arthroplasty and summarized the clinical research findings.

METHODS

We used combinations of "revision," "replacement," "arthroplasty," "augment," "acetabular," and "hip" to search PubMed, Web of Science, EMBASE, Cochrane Library databases, and clinical trial registration platform "Clinicaltrials" for relevant literature. The functional score, restoration of hip center of rotation, revision of implants, and complications were analyzed. Patients were divided into 3 subgroups according to the mean follow-up period. Overall, 19 reports involving 647 patients (655 hips) were selected. The mean age at the time of surgery was 63 years (range, 24-106) and the mean follow-up duration was 66 months (range, 11-204).

RESULTS

Harris Hip Score increased from approximately a mean of 40 points preoperatively to a mean of 84 points postoperatively. The vertical distance between hip center of rotation and teardrop was restored from a preoperative distance of 41.9 to 21.7 mm postoperatively. The overall acetabular revision rate was 4.7%, and the incidence of complications was 8.2%. There were significant differences in the reoperation, acetabular revision, and complication rates among the subgroups.

CONCLUSION

Metal augments used in revision hip arthroplasty are a safe and effective treatment option to correct acetabular defects.

Extended Fixation for Paprosky Type III Acetabular Defects in Revision Total Hip Arthroplasty with a Minimum Follow-Up of 2 Years

OBJECTIVE

Revision of total hip arthroplasty for patients with severe acetabular bone defects is challenging. This study aims to report the minimum 2 years outcome of the iliac extended fixation technique in patients with Paprosky type III acetabular defects.

METHODS

Fifty-seven revision total hip arthroplasty patients were retrospectively reviewed who underwent reconstruction with the concept of iliac extended fixation from 2014 to 2017 in our hospital. We proposed a new concept of "iliac extended fixation" in revision total hip arthroplasty as fixation extending superiorly 2 cm beyond the original acetabular rim with porous metal augments, which was further classified into intracavitary and extracavitary fixation. Patients were assessed using the Harris Hip Score and the Western Ontario and McMaster Universities Osteoarthritis Index Score. Radiographs and patient-reported satisfaction were assessed.

RESULTS

At an average follow-up of 63 months (range 25-88 months), the postoperative Harris Hip Score and Western Ontario and McMaster Universities Osteoarthritis Index scores were significantly improved at the last follow-up (p < 0.001). The center of rotation was significantly improved (p < 0.05). Fifty-three (93.0%) patients were satisfied with the outcome. The extracavitary iliac extended fixation group had higher rate of osteointegration in zone 1A (the superior lateral zone) than the intracavitary iliac extended fixation group (82.3% vs 55.0%, p = 0.015), and significantly more horizontal screws fixation (5.1 ± 24.7° vs 42.3 ± 36.8°, p < 0.001).

CONCLUSION

Intracavitary and extracavitary iliac extended fixation with porous metal augments and cementless cups are effective in reconstructing severe superior acetabular bone defects. The difference in screw direction might reflect the different biomechanics of augment fixation.

Minimum 2-Year Outcomes of a Novel 3D-printed Fully Porous Titanium Acetabular Shell in Revision Total Hip Arthroplasty

Background

Fully porous acetabular shells are an appealing choice for patients with extensive acetabular defects undergoing revision total hip arthroplasty (rTHA). This study reports on the early outcomes of a novel 3-D printed fully porous titanium acetabular shell in revision acetabular reconstruction.

Methods

A multicenter retrospective study of patients who received a fully porous titanium acetabular shell for rTHA with a minimum of 2 years of follow-up was conducted. The primary outcome was rate of acetabular revision.

Results

The final study cohort comprised 68 patients with a mean age of 67.6 years (standard deviation 10.4) and body mass index of 29.5 kg/m² (standard deviation 5.9). Ninety-four percent had a preoperative Paprosky defect grade of 2A or higher. The average follow-up duration was 3.0 years (range 2.0-5.1). Revision-free survivorship at 2 years was 81% for all causes, 88% for acetabular revisions, and 90% for acetabular revision for aseptic acetabular shell failure. Eight shells were explanted within 2 years (12%): 3 for failure of osseointegration/aseptic loosening (4%) after 15, 17, and 20 months; 3 for infection (4%) after 1, 3, and 6 months; and 2 for instability (3%). At the latest postoperative follow-up, all unrevised shells showed radiographic signs of osseointegration, and none had migrated.

Conclusions

This novel 3-D printed fully porous titanium shell in rTHA demonstrated good survivorship and osseointegration when used in complex acetabular reconstruction at a minimum of 2 years.

Level of evidence

IV, case series.

Clinical and radiological outcomes of jumbo cup in revision total hip arthroplasty: A systematic review

Introduction

Many studies have reported the clinical outcomes of a jumbo cup in revision total hip arthroplasty (rTHA) with acetabular bone defect. We conducted a systematic review to access the survivorship and clinical and radiological outcomes of a jumbo cup in rTHA.

Methods

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive literature search from PubMed, MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews was performed with the keywords (“revision” OR “revision surgery” OR “revision arthroplasty”) AND (“total hip arthroplasty” OR “total hip replacement” OR “THA” OR “THR”) AND (“jumbo cup” OR “jumbo component” OR “extra-large cup” OR “extra-large component”). Studies reporting the clinical or radiological outcomes were included. The basic information and radiological and clinical results of these studies were extracted and summarized for analysis.

Results

A total of 19 articles were included in the systematic review. The analysis of clinical results included 953 hips in 14 studies. The re-revision-free survivorship of the jumbo cup was 95.0% at a mean follow-up of 9.3 years. Dislocation, aseptic loosening, and periprosthetic joint infection were the top three complications with an incidence of 5.9%, 3.0%, and 2.1%, respectively. The postrevision hip center was relatively elevated 10.3 mm on average; the mean postoperative leg-length discrepancy was 5.4 mm.

Conclusion

A jumbo cup is a favorable option for acetabular bone defect reconstruction in rTHA with satisfying survivorship and acceptable complication rates.

Segmental Acetabular Defects Managed by Augments in Conjunction with CT During Robotic Total Hip Arthroplasty: A Report of 2 Cases

CASES

We present 2 robotic-assisted hip arthroplasty cases with significant segmental acetabular defects that could compromise cup fixation. We outline an algorithmic planning approach on a computed tomography (CT)-based platform to address these defects by predicting augmentation needs, when component adjustments alone are inadequate, and describe the novel combination of augments in conjunction with robotic-assisted hip arthroplasty.

CONCLUSION

CT-based robotic-assisted hip arthroplasty is a powerful tool to assess and address acetabular deficiencies. Rudimentary augment planning extracts additional value out of the preoperative CT. However, there remains room for intelligent assessment of hip centers and for deliberate augment planning and execution.

Early outcomes of using custom-made augments in revision total hip arthroplasty

INTRODUCTION

The continuing high demand for revision total hip arthroplasty (RTHA) requires not only additional economic costs, but also the search for new, effective methods to manage the reconstruction of acetabular bone loss. This study focuses on the assessment of the clinical and radiographic outcomes after RTHA using custom-made augments (CMA) in the short-term follow-up period.

MATERIALS AND METHODS

We retrospectively analyzed the results of using CMAs in 19 patients (20 hips). The average follow-up period was 41.3 months. All surgery was performed on defect types III and IV as per the Gross and Saleh classification.

RESULTS

There was a statistically significant difference when comparing the Oxford Hip Score before RTHA of 15.0 (Std. deviation-5.9) and after RTHA of 36.3 (Std. deviation-6.3) (p = 0.01). All implants were radiologically stable. CMA has demonstrated a good ability to restore position of hip centre of rotation (HCOR). In the postoperative period, two patients (2 hips) had dislocations. Only one of two patients underwent re-revision due to dislocation.

CONCLUSION

Treatment of uncontained loss of bone stock in RTHA using CMA shows promising clinical and radiographic results at short-term follow-up period; however, dislocation rate is 10% in this study.

Mid-term outcomes of the Wagner Cone Prosthesis™ stem for developmental dysplasia of the hip: minimum two year follow-up

PURPOSE

Treatment of symptomatic developmental dysplasia of the hip (DDH) requires a technically demanding total hip arthroplasty (THA) reconstruction. In patients with DDH, prostheses can be difficult to implant and often face the risk of fracture, mismatch, and loosening. The Wagner Cone Prosthesis™ is a tapered, conical stem which can improve treatment success in this population. We look at midterm survivorship and outcomes of THA for DDH using the Wagner Cone Prosthesis™.

METHODS

We retrospectively analyzed 28 patients (33 hips) with DDH undergoing THA using the Wagner Cone Prosthesis™ between January 2008 and January 2020. Ten, nine, and fourteen included patients were classified as Hartofilakidis A, B, and C, respectively. Survivorship according to Kaplan-Meier analysis was the primary outcome, with re-operation and revision as endpoints. The Oxford hip score (OHS) was used to assess clinical outcome. We used multivariate analysis to determine predictors of poor outcomes. The average follow-up was 4.6 years, with a minimum of two years.

RESULTS

Kaplan-Meier survivorship over the 13-year study period was 93.9 ± 4.2% for all-cause revision as an endpoint and 96.9 ± 3.1% for stem revisions only. The overall reoperation rate was 6.1%, with periprosthetic fracture and dislocation being reasons for re-operation. No patients were revised for aseptic loosening, and no patients were revised for subsidence. OHS improved from 19.3 ± 9.6 (4-39) pre-operatively to 37.6 ± 8.4 (19-48) at latest follow-up (p < 0.05).

CONCLUSION

In patients with DDH, THA with the Wagner Cone Prosthesis™ demonstrates excellent clinical, radiographic, and patient-reported functional outcomes at midterm follow-up.