Total hip arthroplasty with porous tantalum trabecular metal pads in patients with Crowe IV developmental dysplasia of the hip: a midterm followup study.

PURPOSE: Crowe IV developmental dysplasia of the hip (DDH) is a catastrophic hip disease. Moreover, obtaining ideal clinical efficacy in conventional total hip arthroplasty (THA) is often difficult. In this study, we aimed to assess the mid-term clinical results of THA with porous tantalum trabecular metal (TM) pads for acetabular reconstruction in the treatment of Crowe IV DDH. METHODS: A cohort of 28 patients (32 hips) diagnosed with Crowe type IV DDH who underwent acetabular reconstruction during THA using TM pads with scheduled follow-up between 2011 and 2018, were included in this study. Eight cases were men and 24 were women, with a mean age of 48.4 years (range, 36-72 years) and a mean follow-up was 74.3 months (range, 42-132 months). All patients underwent acetabular reconstruction using TM pads and total hip replacement with subtrochanteric osteotomy. RESULTS: At the final follow-up, 28 hips (87.5%) demonstrated mild or no postoperative limping. The Harris Hip Score improved from 58.4 ± 10.6 preoperatively to 85.6 ± 8.9. The mean pain, stiffness, and function scores on the Western Ontario and McMaster University Osteoarthritis index were 86.5 ± 10.2, 87.3 ± 12.4 and 85.4 ± 11.6 respectively. The mean score of patient satisfaction was 90.4 ± 7.6. Additionally, the SF-12 physical summary score was 41.8 ± 5.6 and the SF-12 mental summary score was 51.6 ± 5.4. TM construct survivorship due to all-cause failure was 90.6% at 5 years with 3 hips at risk, 87.5% at 10 years with 4 hips at risk. The survivorship due to failure from aseptic loosening was 96.9% at 5 years with 1hips at risk and 93.75% at 10 years with 2 hips at risk. CONCLUSION: This study demonstrated satisfactory mid-term clinical and radiological results with the application of TM pads for acetabular reconstruction combined with THA in patients with Crowe IV DDH. TRIAL REGISTRATION NUMBER: ChiCTR1800014526, Date: 18/01/2018.

Highly Porous Acetabular Cup and Augment Constructs in Complex Revision Total Hip Arthroplasty: What Predicts 10-Year Implant Survivorship?

BACKGROUND: Porous tantalum acetabular cup and augment constructs have demonstrated favorable outcomes up to 5 years postsurgery despite severe bone loss during revision total hip arthroplasty (THA). Prior literature lacks long-term studies with substantial case numbers. This study aims to assess long-term clinical and radiographic outcomes 10 years postsurgery in patients undergoing revision THA with porous tantalum acetabular cup-augment constructs and determine factors associated with long-term survivorship. METHODS: Between 2000 and 2012, 157 revision THAs were performed in cases with major acetabular defects (mainly Paprosky type IIIA and IIIB) utilizing porous tantalum cup-augment constructs. Pelvic discontinuity was noted intraoperatively in 17 hips (11%). Postoperative radiographs were evaluated at regular intervals for implant stability and radiolucent lines. There were 49 patients who had complete radiographic follow-up at 10 years or longer postsurgery. RESULTS: The 10-year survivorship free of revision of the cup-augment construct for aseptic loosening was 93%, free of any acetabular construct revision was 91%, free of any hip rerevision was 77%, and free of any reoperation was 75%. Pelvic discontinuity was associated with increased risk of reoperation (hazard ratio [HR] = 2.8), any hip rerevision (HR = 3.2), any cup-augment construct revision (HR = 11.8), and aseptic construct revision (HR = 10.0). Of unrevised cases with radiographs at 10 years, 4 hips showed radiographic loosening. Mean Harris hip scores improved from 47 preoperatively to 79 at 10 years. CONCLUSIONS: Porous tantalum acetabular cup-augment constructs used in revision THA with severe acetabular bone loss provide excellent implant survivorship at 10 years when the acetabulum is intact. Due to lower survivorship of cup-augment constructs in cases of pelvic discontinuity, additional construct fixation or stabilization methods are recommended, when a discontinuity is present. LEVEL OF EVIDENCE: IV.

Porous Tantalum Tibial Metaphyseal Cones in Revision Total Knee Arthroplasty: Excellent 10-Year Survivorship.

BACKGROUND: Highly porous metal tibial metaphyseal cones (TMCs) are commonly utilized in revision total knee arthroplasty (TKA) to address bone loss and obtain biologic fixation. Mid-term (5 to 10 year) studies have previously demonstrated excellent survivorship and high rates of osseointegration, but longer-term studies are lacking. We aimed to assess long-term (≥ 10 year) implant survivorship, complications, and clinical and radiographic outcomes after revision TKA with TMCs. METHODS: Between 2004 and 2011, 228 revision TKAs utilizing porous tantalum TMCs with stemmed tibial components were performed at a single institution and were retrospectively reviewed. The mean age at revision was 65 years, the mean body mass index was 33, and 52% were women. Implant survivorship, complications, and clinical and radiographic outcomes were assessed. The mean follow-up was 6.3 years. RESULTS: The 10-year survivorship free of aseptic loosening leading to TMC removal was 97%, free of any TMC removal was 88%, free of any re-revision was 66%, and free of any reoperation was 58%. The most common indications for re-revision were periprosthetic joint infection, instability, and aseptic femoral component loosening. The 10-year nonoperative complication rate was 24%. The mean Knee Society scores increased from 38 preoperatively to 69 at 10 years. There were 8 knees that had evidence of partial, progressive tibial radiolucencies at 10 years. CONCLUSIONS: Porous tantalum TMCs demonstrated persistently durable longer-term survivorship with a low rate of implant removal. The rare implant removals for component loosening or instability were offset by those required for periprosthetic joint infection, which accounted for 80% of cone removals. Porous tantalum TMCs provide an extremely reliable tool to address tibial bone loss and achieve durable long-term fixation in revision TKA. LEVEL OF EVIDENCE: IV.

Analysis of peripheral bone reconstruction after the failure of hip osteonecrosis treatment with porous tantalum rod implantation.

PURPOSE: Failure of porous tantalum rod (PTR) implantation in treating early osteonecrosis of femoral head (ONFH) has been frequently reported, but the underlying mechanism remains uncertain, which raised the concern of its efficacy. The study aimed to discuss the underlying mechanism from the perspectives of bone reconstruction and pathological changes. METHODS: Five patients with PTR implantation experienced total hip arthroplasty (THA) due to recurrent pain, whose femoral heads were collected as "tantalum group." Normal (fracture) and necrotic femoral heads were respectively collected (both n = 5) after THA. The bone quality and structure, biomechanical properties, and histopathological features were analyzed by micro-CT scanning, mechanical measurement, and histological examination. RESULTS: Both the tantalum group and necrotic group had significantly poorer bone quantity and quality than the normal group. Three-dimensional imaging reconstruction showed that the trabeculae of the tantalum group were poorest in quality. Significant differences in terms of bone quality, structure, and biomechanical properties were present between the inside and outside regions around PTR, which revealed abnormal bone reconstruction. Biomechanical analysis revealed inferior properties in the tantalum group and necrosis group. H&E staining demonstrated neutrophil infiltration among the peripheral trabeculae around PTR, and the inflammation cells were significantly more abundant than that in the normal and necrosis groups. CONCLUSION: Abnormal bone reconstruction around PTR was an important cause for failure of PTR implantation in the treatment of ONFH, which was related to biomechanical stress distribution and chronic inflammation infiltration. Insufficient biomechanical support and inflammatory trabeculae edema might account for the recurrent pain.

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

AIM: 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. PATIENTS AND METHODS: 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 62.5 years (34 to 85) and mean follow-up was 75 months (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). RESULTS: At a mean 6.25 years 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. CONCLUSION: 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.

Porous tantalum implant for treatment of early-stage osteonecrosis of the femoral head: a minimum 5-year follow-up study.

BACKGROUND: To evaluate the survival rate of porous tantalum rod implantation in the treatment of osteonecrosis of the femoral head (ONFH), evaluate its clinical effect and imaging results. METHODS: From January 2008 to December 2013, porous tantalum rod implantation for ONFH was performed in two institutions. Statistical analysis of operation data, including operation time, blood loss and blood transfusion were recorded. RESULTS: 52 hips received complete follow-up, the average follow-up time was 85.7 months (60-132 months). 24 hips turned to THA at the end of follow-up (46.2%), the average time was 44.3 ± 32.8 months, and the average Harris hip score before THA was 57.1 ± 7.6. Cox proportional-hazards model revealed that Association Research Circulation Osseous (ARCO) stage (P = 0.017), bone marrow edema (P = 0.006) and age > 40 years (P = 0.043) were independent risk factors for conversion to THA. CONCLUSION: ARCO stage, age and bone marrow edema were risk factors for the failure of porous tantalum rod implantation to convert to THA.

Mid-Term Survivorship, Performance, and Predictors of Outcome in Primary Total Hip Arthroplasty With a Porous Tantalum Femoral Prosthesis.

BACKGROUND: Femoral stem subsidence is a known cause of early implant failure, increasing the risk for aseptic loosening and periprosthetic fracture. Overall survivorship and subsidence in a novel porous tantalum-coated femoral prosthesis have not been well-studied. METHODS: Consecutive patients undergoing primary total hip arthroplasty with a porous tantalum-coated femoral prosthesis between January 2008 and January 2015 with minimum 5-year follow-up were included. Clinical and radiographic data were obtained from hospital and office records. Multivariate logistic regression analyses were used to determine predictors of subsidence and clinical outcomes. Kaplan-Meier survivorship curves were performed to illustrate primary failure endpoints of (1) all-cause revision and (2) femoral prosthesis revision. RESULTS: A total of 398 patients with a mean (±standard deviation) age of 61.0 ± 11.5 years, body mass index (BMI) 32.8 ± 8.0 kg/m2, and follow-up of 6.9 (range 5.0-11.2 years) were included. Survivorship at 5 years was 94.9% for all-cause revision and 98.0% for femoral component revision. Average subsidence was 1.8 ± 1.3 mm (range 0-15.5), with 8.1% patients experiencing subsidence >5 mm. Statistically significant mean improvements were observed at latest follow-up in the Hip Disability and Osteoarthritis Outcome Score Joint Replacement (40.6 ± 11.5 vs 85.2 ± 10.1, P < .001), Harris Hip Score (38.0 ± 12.0 vs 79.5 ± 12.8, P < .001), and hip flexion (92.8° ± 15.3° vs 103.3° ± 10.3°, P < .001). Multivariate logistic regression analyses revealed that greater BMI (odds ratio [OR] 1.17, P < .001), non-white/Caucasian race (OR 2.0, P = .036), and female gender (OR 2.4; P = .005) conferred a higher likelihood of subsidence >3 mm. BMI was a statistically significant and independent predictor of subsidence >5 mm (OR 1.25, P < .001) and subsidence >7 mm (OR 1.25, P < .001). CONCLUSION: The trabecular metal taper femoral prosthesis conferred excellent clinical outcome improvement and survivorship. Increasing BMI was independently associated with an increased risk of subsidence in these patients and caution is recommended in utilizing this implant in obese, morbidly obese, and super morbidly obese populations.

Preliminary clinical results of coated porous tibia cones in septic and aseptic revision knee arthroplasty.

PURPOSE: To analyze the first results of calcium-phosphate-coated porous tibia cones. METHODS: Patients treated with TrabecuLink®-CaP Cones were retrospectively recruited from January 2016 to December 2017. These custom-made cones were produced using titanium alloy Ti-6Al-4 V (Tilastan®) and using additive manufacturing with a special calcium-phosphate coating (HX®-coating). Clinical outcome was evaluated using Oxford Knee Score. For radiological evaluation of the implants, patients sent us outpatient taken radiographs. A minimum follow-up of one year was required. Lastly, we analyzed postoperative complications and revision rates. RESULTS: 52 patients with revision knee arthroplasty (RKA) were recruited for final analysis, of whom, we had 17 septic RKAs (33%) and 35 aseptic cases of RKA (67%). The bone defects were grouped into 17 AORI Type 2A (32.7%), 14 Type 2B (26.9%) and 21 Type 3 (40.4%). After a mean follow-up of 22 months (13.2-34.8; SD = ± 10), we had 4 surgical revisions (7.7%), 2 septic and 2 aseptic cases. The mean Oxford Knee Score was 28.6 points (8-47; SD = ± 10). 22 of 28 radiographs (78.6%) showed regular positioning of the cones and TKAs at a mean follow-up of 16.8 months (13.2-34.8; SD = ± 6). Three patients (10.7%) showed slight radiolucencies in the bone-cement interfaces and 3 patients (10.7%) had beginning heterotopic ossifications. CONCLUSIONS: This study shows the initial clinical results of calcium-phosphate-coated tibia cones showing a good functional outcome. Further research should focus on long-term clinical and radiological follow-up.

Periprosthetic Loss of Bone Mineral Density After Cementless Porous Tantalum and Cemented Total Knee Arthroplasties: A Mean of 11-Year Concise Follow-Up of a Previous Report.

BACKGROUND: Our previous study showed that the decrease in relative change of bone mineral density (BMD) in the lateral part of the tibia was significantly less in the group treated with the cementless porous tantalum component than in the group treated with the cemented cobalt-chromium tibial component up to 5 years after the operation. However, the long-term benefits of porous tantalum tibial component on BMD have not been proven. The aim of this study was to update a matched cohort study at a minimum of 6 years' follow-up period. METHODS: Twenty patients with a porous tantalum tibial component and 18 patients with a cemented cobalt-chromium-alloy tibial component were investigated for more than 6 years in the present study. The mean follow-up period was 11.4 years. Dual X-ray absorptiometry was used to measure the BMD. RESULTS: The decrease in relative change of BMD in the lateral aspect of the tibia was significantly less with the porous tantalum tibial component than that with the cemented cobalt-chromium tibial component up to 5 years. However, at the final follow-up period, no significant difference was observed in the relative change of BMD between the 2 groups. No prosthetic migration or periprosthetic fracture was detected in either group. CONCLUSION: The present study is one of the studies with the longest follow-up period on BMD after total knee arthroplasty. Porous tantalum tibial component did not have a favorable effect on the BMD of the proximal tibia after total knee arthroplasty for long term.

Bone response to porous tantalum implants in a gap-healing model.

OBJECTIVES: The objective of this study was to determine the relative osteogenic behavior of titanium implants with or without a porous tantalum modification when placed with a gap between the implant and existing bone. MATERIALS AND METHODS: A gap-healing model in the rabbit tibia was used for placement of titanium implants. Forty-eight rabbits received 96 implants, with 48 of the implants containing a porous tantalum middle section and the remaining 48 implants were composed of solid titanium. After 4, 8, and 12 weeks of healing, biomechanical stability was measured with removal torque testing, implant-adherent cells were isolated for analysis of osteogenic gene expression, and histomorphometric analysis was performed on sections of the implants and surrounding bone. RESULTS: Increased osteogenic activity at 4 weeks was demonstrated by upregulation of key osteogenic genes at implants containing porous tantalum which was accompanied by greater bone-implant contact at 4, 8, and 12 weeks and significantly greater removal torque at 8 and 12 weeks. CONCLUSIONS: Implants containing porous tantalum demonstrated increased peri-implant bone formation within this gap-healing model as shown by significant differences in biomechanical and histomorphometric outcomes. Such implants may represent an alternative to influence bone healing in surgical sites with an existing gap.

Influence of the implant diameter and bone quality on the primary stability of porous tantalum trabecular metal dental implants: an in vitro biomechanical study.

OBJECTIVES: The aim of this study was to evaluate the primary, initial stability of Porous Tantalum Trabecular Metal™ implants (TM) compared with Tapered Screw Vent® implants (TSV) with different diameters, inserted in two bone densities. METHODS: A total of 160 implants (80 TM and 80 TSV) with narrow (3.7 mm) and conventional (4.1 mm) diameters and the same length (10 mm) were placed in artificial bone blocks representing bone qualities II and IV. The implant stability was evaluated by insertion torque (IT) and Resonance Frequency Analysis. Statistical analysis was performed with non-parametric Kruskal-Wallis test with Dunn post-test for the differences between groups. RESULTS: The results showed higher ISQ values in dense bone compared with soft bone for all the groups (P < 0.05). Conventional-diameter implants (TSV and TM) showed higher ISQ and IT values compared with narrow implants (TSV and TM) in dense and soft bone (P < 0.05). Tapered TSV implants showed higher stability in soft bone compared with TM implants (P < 0.05). In dense bone, differences were not observed between narrow TSV 3.7 mm and TM 3.7 mm implants (P > 0.05). CONCLUSIONS: Within the limitations of this study, it can be concluded: In dense bone blocks, the wider diameter implants are more stable than narrow implants. In soft bone blocks, the tapered TSV implants are more stable than TM implants.

Application of combined porous tantalum scaffolds loaded with bone morphogenetic protein 7 to repair of osteochondral defect in rabbits.

PURPOSE: Porous tantalum (PT) has been widely used in orthopaedic applications for low modulus of elasticity, excellent biocompatibility, and the microstructures similar to cancellous bone. In order to improve the biological activity of PT, biologically active factors can be combined with the material. The purpose of this study was to investigate if bone morphogenetic protein 7 (BMP-7) modifications could enhance the repairing of cartilage of PT in osteochondral defect in medial femoral condyle of rabbits. METHODS: A cylindrical osteochondral defect model was created on the animal medial femoral condyle of and filled as follows: PT modified with BMP-7 for MPT group, non-modified PT for the PT group, while no implants were used for the blank group. The regenerated osteochondral tissue was assessed and analyzed by histological observations at four, eight and 16 weeks post-operation and evaluated in an independent and blinded manner by five different observers using a histological score. Osteochondral and subchondral bone defect repair was assessed by micro-CT scan at 16 weeks post-operation, while the biomechanical test was performed at 16 weeks post-operation. RESULTS: Briefly, higher overall histological score was observed in the MPT group compared to PT group. Furthermore, more new osteochondral tissue and bone formed at the interface and inside the inner pores of scaffolds of the MPT group compared to PT group. Additionally, the micro-CT data suggested that the new bone volume fractions and the quantity and quality of trabecular bone, as well as the maximum release force of the bone, were higher in the MPT group compared to PT group. CONCLUSIONS: We demonstrated that the applied modified PT with BMP-7 promotes excellent subchondral bone regeneration and may serve as a novel approach for osteochondral defects repair.

Real-time computerised tomography assisted porous tantalum implant in ARCO stage I-II non-traumatic osteonecrosis of the femoral head: minimum five-year follow up.

PURPOSES: This study was established to investigate the medium-term clinical effect of real-time CT assisted porous tantalum implant for the treatment of ARCO stage I-II non-traumatic osteonecrosis of the femoral head (ONFH). METHODS: This study comprised 24 ONFH patients (29 hips) who were treated with intra-operative real-time CT accurate rapid positioning assisted drilling decompression, lesion removal and porous tantalum implant. Harris score, VAS score and imaging in pre-operation and follow-up period were recorded. RESULTS: The average operative time and intra-operative blood loss were 72.6 min and 158.8 ml, respectively. The mean follow-up was 5.4 years. No femoral head penetrating, wound infection, and death occurred. Harris and VAS score improved significantly (73.78 vs. 88.11; 7.13 vs. 2.66) at last follow-up (P < 0.05). The functional improvement and pain relief rate was 100% at six months after operation. The effective rate was 86.21% at 12 months after operation and last follow-up. Five pre-operative ARCO stage I hips had no radiographic progress. Meanwhile, four among the 24 ARCO stage II hips progressed into stage III between eight and 12 months after surgery, among which two progressed into stage IV and two remained in stage III at the last follow-up. The average value of Kerboul combined necrotic angle was 263.24°. There was no progress in Kerboul combined necrotic angle among the grades 2 and 3 patients. However, among the six cases at grade 4, four cases with post-operative progress, two patients converted to THA. CONCLUSIONS: Our technique is safety and effective in the treatment of ARCO stage I-II non-traumatic ONFH.

Is there a relationship between the load distribution on the tibial plateau and hip knee ankle angle after TKA?

INTRODUCTION: This study asked whether differences in coronal alignment after total knee arthroplasty (TKA) affect the load distribution on the tibial plateau. The aim of this study was to investigate the correlation between coronal alignment and the load distribution on the tibial plateau after TKA, using three-dimensional multi-detector-row-computed tomography (3D-MDCT). MATERIALS AND METHODS: In this study, we performed 84 cementless TKA with porous tantalum modular tibial component (PTMT) and divided into three groups based on post-operative hip-knee-ankle (HKA) angle: varus alignment group (n = 22), (176° ≧) neutral alignment group (n = 45), (180° ± 3°), and valgus alignment group (n = 17) (184° ≦).The changes in bone quality parameters of trabecular patterns under peg of PTMT were interpreted as load distribution due to changes in alignment. The relationship between HKA angle and load distribution on the tibial plateau was analyzed every 6 months for 4.5 years by measuring Bone marrow contents/tissue volumes (mg/cm3) and bone volumes/tissue volumes (%) under peg of porous tantalum modular tibial component by visualizing three dimensionally with 3D-osteo-morphometry software. RESULTS: There were no correlations between HKA angle and the load distribution on the tibial plateau after TKA at all periods. There was a significantly higher increase in the medial region than the lateral about the BMC/TV and BV/TV values, regardless of the post-operative alignment after TKA for all periods. The relative BMC/TV and BV/TV changes at medial region in varus alignment group were significantly lower than the neutral and the valgus alignment groups of pre-operative medial osteoarthritis of the knee. CONCLUSIONS: As far, it can be concluded by the study and the methods used therein that there were no relationships between the load distribution on the tibial plateau and HKA angle after TKA. LEVEL OF EVIDENCE: Therapeutic study, Level III.

Cementless Porous Tantalum Monoblock Tibia vs Cemented Modular Tibia in Primary Total Knee Arthroplasty: A Meta-Analysis.

BACKGROUND: With the introduction of new fixation systems and designs, there has been a recent reemergence of interest in cementless fixation of the tibial component in total knee arthroplasty. However, little is known regarding the clinical features and survivorship of the cementless porous tantalum monoblock tibial component compared to the conventional cemented modular tibial component. METHODS: We conducted a literature search of multiple databases for comparative studies published before June 2015 that investigated the outcomes of cementless porous tantalum monoblock tibia vs conventional cemented modular tibia. A pooled analysis was performed. The outcomes of interest were postoperative functional score, range of motion, Western Ontario and McMaster University Osteoarthritis Index, total complications, reoperation, radiolucent lines, loosening of the tibial component, and length of operation. RESULTS: Six studies involving 977 patients were eligible for the meta-analysis. The use of a cementless porous tantalum monoblock tibial component may associate with a slightly higher functional score, fewer radiolucent lines, and shorter operation. No significant difference was seen in regard to the range of motion, Western Ontario and McMaster University Osteoarthritis Index, total complications, reoperation, and loosening of the component between the 2 groups. CONCLUSION: However, due to variation among the included studies, the use of cementless porous tantalum monoblock tibia seems to achieve no substantial superiority over that of the conventional cemented modular tibia at 5-year follow-up. Data concerning the long-term prognosis of this novel implant should continue to be collected and analyzed.

Survivorship of a Porous Tantalum Monoblock Acetabular Component in Primary Hip Arthroplasty With a Mean Follow-Up of 18 Years.

BACKGROUND: The use of porous tantalum for the acetabular component in primary total hip arthroplasty (THA) has demonstrated excellent short-term and midterm results. However, long-term data are scarce. The purpose of this prospective study is to report the long-term clinical and radiologic outcome following use of an uncemented porous tantalum acetabular component in primary THA with a minimum follow-up of 17.5 years, in a previously studied cohort of patients. METHODS: We prospectively followed 128 consecutive primary THAs in 140 patients, between November 1997 and June 1999. A press-fit porous tantalum monoblock acetabular component was used in all cases. All patients were followed clinically and radiographically for a mean of 18.1 years (range, 17.5-19 years). RESULTS: Mean age of patients at the time of operation was 60.4 years. Harris hip score, Oxford hip score, and range of motion were dramatically improved in all cases (P < .001). At last follow-up, all cups were radiographically stable with no evidence of migration, gross polyethylene wear, progressive radiolucencies, osteolytic lesions, or acetabular fractures. The survivorship with reoperation for any reason as end point was 92.8% and the survivorship for aseptic loosening as an end point was 100%. CONCLUSION: The porous tantalum monoblock cup in primary THA demonstrated excellent clinical and radiographic outcomes with no failures because of aseptic loosening at a mean follow-up of 18.1 years.

Cementless vs Cemented Tibial Fixation in Primary Total Knee Arthroplasty.

BACKGROUND: The ideal fixation for modern tibial components in total knee arthroplasty (TKA) remains controversial with uncertainty on whether cementless implants can yield equivalent outcomes to cemented fixation in early follow-up. METHODS: A series of 70 consecutive cases with reverse hybrid cementless fixation were matched to 70 cemented cases from 2008 to 2015 based on implant design and patient demographics. RESULTS: Cementless TKA demonstrated greater aseptic loosening (7 vs 0, P = .013) and revision surgery (10 vs 0, P = .001) than cemented fixation within 5 years of follow-up, but with no clinically significant differences in outcome scores. CONCLUSION: It remains unclear whether early aseptic loosening in cementless TKA can be reduced with enhanced adjunct fixation and what proportion of early failure justifies the potential lifelong fixation through biologic ingrowth of cementless tibial components.

Long-Term Clinical and Radiographic Outcomes of Porous Tantalum Monoblock Acetabular Component in Primary Hip Arthroplasty: A Minimum of 15-Year Follow-Up.

BACKGROUND: The porous tantalum monoblock cup has demonstrated excellent short-term and midterm clinical and radiographic outcomes in primary THA, but longer follow-up is necessary to confirm the durability of these results into the second decade. The purpose of this study is to report the clinical and radiographic outcomes for this monoblock cup with a minimum 15-year follow-up. METHODS: From June 1998 to December 1999, 61 consecutive patients (63 hips) underwent primary THA with a tantalum monoblock acetabular component. All patients were followed clinically and radiographically for a minimum of 15 years. At a mean of 15.6 years (range, 15-16 years) of follow-up, 5 patients had died, and 4 had been lost to follow-up, leaving 52 patients (54 hips) for analysis. The underlying diagnosis that led to the primary THA was primary osteoarthritis in 43 hips, avascular necrosis in 4, developmental hip dysplasia in 3, rheumatoid arthritis in 3 and post-traumatic osteoarthritis in 1. RESULTS: One cup was revised for deep infection; at surgery, the cup showed osseointegration. At a mean follow-up of 15.6 years (range, 15-16 years), the survivorship with cup revision for aseptic loosening as end point was 100%. There was no radiographic evidence of loosening, migration, or gross polyethylene wear at last follow-up. The mean Harris Hip Scores improved from 47 points preoperatively to 94 points. CONCLUSION: The porous tantalum monoblock cup in primary THA demonstrated excellent clinical and radiographic outcomes with no failures because of osteolysis or loosening at a minimum follow-up of 15 years.

Total Knee Arthroplasty Using Cementless Porous Tantalum Monoblock Tibial Component: A Minimum 10-Year Follow-Up.

BACKGROUND: Cementless fixation in total knee arthroplasty (TKA) was introduced to improve the longevity of implants but has yet to be widely adopted because of reports of higher failure rates in some series. The cementless tantalum monoblock tibial component, in contrast, has shown successful short-term results, but long-term survivorship with this design is still lacking. The purpose of this study was to investigate the minimum 10-year clinical and radiographic results of the cementless tantalum monoblock tibial component in primary TKA. METHODS: From March 2002 to March 2005, 33 patients (33 knees) underwent primary TKA with a cementless tantalum monoblock tibial component. All patients were followed clinically and radiographically for a minimum of 10 years (mean 11.5 years, range 10-13 years). No patients were lost to follow-up. The underlying diagnosis that led to the primary TKA was primary osteoarthritis in 31 knees and post-traumatic osteoarthritis in 2 knees. RESULTS: None of the components was revised. At a minimum 10-year follow-up, the survivorship with reoperation for any reason as end point was 96.9%. With tibial component revision for aseptic loosening or osteolysis as the end point survivorship was 100%. There was no radiographic evidence of tibial component loosening, subsidence, osteolysis, or migration at the time of the latest follow-up. The mean Knee Society knee scores improved from 56 points preoperatively to 93 points at the last clinical visit. CONCLUSION: The porous tantalum tibial monoblock component demonstrated excellent clinical and radiographic outcomes with no component revisions for aseptic loosening at a minimum follow-up of 10 years.

Early failures of porous tantalum osteonecrosis implants: a case series with retrieval analysis.

BACKGROUNDS: Porous tantalum osteonecrosis implants have been used in femoral head necrosis for several years, while the clinical outcomes were mixed. As a joint-preserving surgery, early necrosis deterioration and conversion to total hip arthroplasy failed our expectation. We hence investigate an observational study with retrieval analysis to find out the underlying reasons. METHODS: Thirteen patients were treated with core decompression and implantation of a tantalum rod. The cases were evaluated both functionally and radiologically. We retrieved and analyzed the micro-structural changes and the histopathologic features of four early failed femoral heads with scanning electron microscopy, histopathologic examination, and micro-CT scaning. RESULTS: All implants were placed in proper positions. One-year survival rate was 64.29 % with a HSS score of 81.11 ± 15.62. Four patients converted to arthroplasty in a mean time of 305 days (0.84 years), with a HSS score of 43.75 ± 7.5 at the last follow-up. A liquid layer surrounded the tantalum implant was noted on MRI in all four failed cases. Volume render CT remodeling revealed interspace between the metal and bone. Scanning electron microscopy and histopathologic examination indicated sparse and isolated bone ingrowth into the implants. The remodeled trabecular bone and the increased density around the peri-implant area were illustrated with micro-CT scaning. CONCLUSIONS: The deterioration of early failed tantalum implant exceeds the nature of osteonecrosis progression. Rather than insufficient mechanical support resulting in improper position and invalid bone ingrowth, nullification of core decompression and consequential intra-osseous pressurization probably led to early failure of porous tantalum osteonecrosis implants.