A multicenter, randomized controlled trial comparing a second-generation uncemented trabecular metal-backed vs. cemented polyethylene glenoid component in total shoulder arthroplasty: 5-year results.

BACKGROUND: Previously, we reported early (2-year) findings from a randomized controlled trial comparing a second-generation uncemented trabecular metal-backed (TM) glenoid vs. cemented polyethylene glenoid (POLY) in patients undergoing a total shoulder arthroplasty. The purpose of the current study is to report disease-specific quality of life, clinical, patient-reported, and radiographic outcomes at midterm (5-year) from this trial. METHODS: Five surgeons from 3 centers participated. Patients 18-79 years with a primary diagnosis of glenohumeral osteoarthritis were screened for eligibility. Randomization to an uncemented TM or cemented POLY glenoid was performed intra-operatively after adequate bone stock was confirmed. Study intervals were baseline, 2- and 5-year postoperative. The primary outcome was the Western Ontario Osteoarthritis Shoulder (WOOS) quality of life score. Secondary outcomes included the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, EuroQol-5 Dimensions, and 12-Item Short Form Health Survey scores and clinical and radiographic examinations. Radiographic images were reviewed for metal debris according to Endrizzi. Mixed effects repeated measures analysis of variance for within- and between-group comparisons were performed. RESULTS: Of the 104 patients who consented, 93 were randomized (46 TM; 47 POLY). There were no differences between groups at baseline (TM: mean age 66.5 years [standard deviation (SD) 6.4], 24 male and 22 female; and POLY: mean age 68.4 years [SD 5.5], 23 male / 24 female). Mean (SD) WOOS scores at baseline and 2 and 5 years were as follows: TM, 32 (21), 92 (13), and 93 (11); POLY, 27 (15), 93 (11), and 93 (10), respectively. No statistical or clinically relevant differences were noted with patient-reported outcomes between groups. Metal debris was observed in 11 (23.9%) patients, but outcomes were not negatively impacted, and debris severity was minor (grades 1 and 2). Complication rates were similar between groups (TM: 7 of 46 [15.2%], and POLY: 8 of 47 [17.0%]; P = .813). No aseptic glenoid failures were reported, but 1 patient in the TM group required revision because of infection. CONCLUSIONS: Our short-term (2-year) findings were maintained with longer follow-up. At 5 years postoperation, there were no statistically or clinically significant differences between an uncemented second-generation TM glenoid and a cemented polyethylene glenoid with respect to disease-specific quality of life or patient-reported outcomes. No glenoid implant failures were reported, and complication rates were similar between groups. Only one complication was glenoid related (1 infection in the TM group). Metal debris was observed in 23.9% of patients with a TM glenoid but did not negatively influence implant survival, patient-reported outcomes, or shoulder function.

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.

INTRODUCTION: The 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 METHODS: In 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. RESULTS: The 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). CONCLUSIONS: This 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.

Reconstruction of severe acetabular defects (Paprosky type III A) in total hip arthroplasty using modular tantalum augments in combination with a cemented cup.

PURPOSE: Acetabular defect reconstruction can be a complex and challenging surgical procedure, with stable long-term fixation of the implants remaining the ultimate goal. The purpose of this study was (1) to evaluate the radiological and clinical outcome of complex acetabular reconstruction surgery with the use of modular tantalum TM augments in combination with cemented revision cups; (2) to investigate blood tantalum concentrations in these patients; and (3) to report complications and mechanisms of failure related to this procedure at mid-term follow-up (mean 4.5 years). METHODS: We retrospectively reviewed 29 patients (29 hips) with severe acetabular bone loss (Paprosky type III A) reconstructed using a modular tantalum TM augment in combination with a cemented cup. We evaluated the implant survival and the radiological and clinical outcomes after a mean follow-up of 4.5 years (SD 2.2; range 8.4 - 2.1 years) using patient reported outcome scores (PROMs). Blood samples were analysed regarding tantalum concentration and compared with a control group. RESULTS: The cumulative survival rate at 4.5 years with the endpoint "revision of the acetabular component for any reason" was 96.2% (95% Confidence Interval 75.7-99.5). The PROMs improved significantly up to the latest follow-up, and radiographic data showed only one patient with signs of initial implant migration with a broken screw and a change of the position of the augment and the cup. Mean blood tantalum concentrations were significantly higher in the study group (0.16 µg/L) compared to the control group (0.002 µg/L) (P < 0.001). CONCLUSIONS: This study has demonstrated good mid-term (mean 4.5 years) clinical and radiological outcomes of modular tantalum TM augments in combination with a cemented cup for the reconstruction of major acetabular defects. Mean blood tantalum concentrations were increased in patients with stable tantalum implants compared to healthy controls.

Epiphyseal fixation in revision total knee arthroplasty: a comparison between trabecular metal and titanium augments.

INTRODUCTION: The purpose of this retrospective study was to compare the medium-term clinical and radiographic outcomes of two series of patients treated for revision TKA: one implanted with trabecular metal (TM) augments and one implanted with classic titanium augments. MATERIALS AND METHODS: A total of 85 patients with a type 2 AORI defect underwent revision TKA and were treated either with TM epiphyseal augments directly screwed in the bone or with traditional titanium augments. There were 46 patients in the TM group and 39 patients in the titanium group included in the study. All the patients received the same varus-valgus constrained implant and no metaphyseal fixation devices were used. RESULTS: After a mean follow-up of 66.4 months, no statistically significant difference was observed in terms of failure for aseptic loosening between the two groups (4% in the TM group and 7.8% in the titanium group, p = 0.35). The ten-year survival using aseptic loosening as endpoint was 90.5% (95% CI 94.1-98.6) in the TM group and 85% (95% CI 101.9-119.3) in the titanium group (p = 0.26). A statistically significant difference was detected for the presence of RLL. No RLL were found under the studied TM augments compared to 13.7% of the titanium augments (p = 0.01). CONCLUSION: The use of TM augments directly screwed to the epiphysis of the femur and the tibia reduced the incidence of RLL compared to standard titanium augments during revision TKA with promising medium-term results.

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

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

Evaluation of clinical and radiographic outcomes after total shoulder arthroplasty with inset Trabecular Metal-backed glenoid.

BACKGROUND: Trabecular Metal (TM)-backed glenoid implants were introduced for their theoretical ability to increase osseointegration while minimizing wear and the risk of loosening in total shoulder arthroplasty (TSA). Initial follow-up studies of TM-backed glenoids demonstrated high rates of metallic debris formation around the implant site, raising concerns about longevity. More recent data suggest that metallic debris formation may be less prevalent than previously reported and that the implants may have positive long-term outcomes regardless of debris. The goal of our study was to assess the clinical and radiographic outcomes at mid-term follow-up of TSA using a TM-backed glenoid implant placed with full backside support using an inset technique. We hypothesized that our clinical and radiographic outcomes would be good using this technique. METHODS: We retrospectively reviewed the charts of 39 patients who underwent 41 TSA procedures with a Zimmer Biomet TM-backed glenoid component performed by a single surgeon between January 2010 and March 2016. After exclusions for death unrelated to surgery and loss to follow-up, 35 patients (37 shoulders) with minimum 2-year clinical follow-up were included in the study. The glenoids were all placed in an inset fashion with full backside support. Clinical, patient-reported, and radiographic outcomes were analyzed. RESULTS: The average follow-up period was 7.2 years (range, 2-11 years). At final follow-up, average shoulder elevation was 153° ± 22° and average external rotation was 53° ± 12°. The average American Shoulder and Elbow Surgeons score was 86.8 ± 19.0, and the average visual analog scale score was 1.3 ± 2.4. Metallic debris was found in 9 shoulders (27%), and radiolucency was observed around the glenoid components in 13 shoulders (39%) on the final postoperative radiographs. Metallic debris and radiolucency findings were low in severity, with average grades of 0.32 (standard deviation, 0.54) and 0.39 (standard deviation, 0.50), respectively. There were no reoperations. CONCLUSION: This study of 37 shoulders undergoing TSA with a TM-backed glenoid demonstrated 100% implant survivorship at an average follow-up of 7 years. Clinical outcomes were excellent despite the occurrence of some metallic debris formation. The findings suggest that a TM-backed glenoid component implanted in an inset fashion to achieve full backside support can provide good clinical and patient-reported outcomes in TSA patients at mid-term follow-up and suggest that continued consideration of the role of TM-backed glenoids and the optimal technique for implantation may be warranted.

Trabecular metal monoblock versus modular tibial trays in total knee arthroplasty: meta-analysis of randomized control trials.

PURPOSE: Total knee arthroplasty is one of the significantly evolving procedures with different knee designs available in the market. The continued development of these prosthesis resulted in improvement of the implant survivorship and patient satisfaction. This study is an RCT-based meta-analysis aimed to compare two designs of total knee replacement: the conventional modular and the monoblock trabecular metal tibial trays. METHODS: This meta-analysis was performed by a literature review according to the PRISMA guidelines. A detailed search of the English literature was done using the PubMed, Medline, CINAHL, Cochrane, Embase, and Google Scholar databases. Only randomized control trials were included in the analysis after ensuring homogeneity. RevMan V.5.0.18.33 (The Cochrane Collaboration, Copenhagen, Denmark) was used to perform the meta-analysis. Extracted outcome measures were Knee Society score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, survivorship, complication rate, and radiostereographic analysis. RESULTS: Seven randomized control trials with 635 patients were eligible for our analysis after they met our inclusion criteria. Three hundred twelve patients received monoblock tibias, and the other 323 patients received modular tibial trays during their total knee arthroplasty surgeries. There were statistically significant superiority of the modular knees in the functional Knee Society and WOMAC scores at five years (P = 0.003 and 0.05, respectively). The modular design was also more stable on RSA at two years (P < 0.0001). CONCLUSION: Modular and monoblock tibial trays are comparable knee designs with comparable survivorship and complication rates. However, the modular knees had better mid-term functional outcome and are more stable on radiostereographic analysis.

Primary Stability of Trabecular Metal Implant in Comparison to Fully Threaded Implants: In Vitro Study Simulating Immediate Implant Placement.

The aim of this study was to evaluate primary stability of 3.7-mm diameter porous tantalum Trabecular Metal (TM) implant, and compare it to fully threaded implants, in the in vitro model of immediate implant placement in the anterior maxilla. A total of 60 implants were placed into bovine ribs using surgical guides. Implants were divided in 3 groups of 20 according to the design: TM, Tapered Screw-Vent (TSV), and NobelReplace. To simulate immediate placement in anterior maxilla, implants were placed under a sharp angle toward the ribs, not fully submerged. Placement angle of 20.7° was calculated after analysis of 148 virtually planned implants on cone beam computerized tomography scans of 40 patients. No statistically significant difference in implant stability quotient (ISQ) was found between TM (65.8 ± 2.6), TSV (64.7 ± 2.7), and NobelReplace (64.6 ± 2.7). TSV implants achieved higher insertion torque (37.0 ± 4.8 Ncm) than TM (32.9 ± 5.2 Ncm) and NobelReplace (23.2 ± 3.3 Ncm). TSV had the shortest insertion time of 13.5 ± 1.0 seconds, compared to 15.2 ± 1.2 seconds for TM, and 19.7 ± 1.7 seconds for NobelReplace. Pearson correlation analysis showed significantly correlated insertion torque and ISQ values for TM group (P = .011, r = .56), a nonsignificant correlation was found for TSV and NobelReplace. The results of the present study indicate that TM implant can achieve good primary implant stability in insertion torque and resonance frequency analysis.

Cemented versus uncemented fixation of second-generation Trabecular Metal glenoid components: minimum 5-year outcomes.

BACKGROUND: Total shoulder arthroplasty (TSA) with second-generation Trabecular Metal™ implants (Zimmer, Warsaw, IN, USA) has shown good short-term outcomes. Differences in outcomes between cemented and uncemented fixation are unknown. This study compared the clinical, radiographic, and patient-rated outcomes of TSA with cemented vs. uncemented TM glenoids at minimum 5-year follow-up. METHODS: Patients who underwent anatomic TSA with second-generation TM glenoid components for primary osteoarthritis were identified for minimum 5-year follow-up. The patients were divided into 2 groups: cemented and uncemented glenoid fixation. Outcome measures included implant survival, patient-rated outcome scores (Patient-Reported Outcomes Measurement Information System [PROMIS] and American Shoulder and Elbow Surgeons scores), shoulder range of motion, and radiographic analysis. Findings were compared between groups. RESULTS: The study included 55 shoulders: 27 in the cemented group (21 with full radiographic follow-up) and 28 in the uncemented group (22 with full radiographic follow-up). Both groups had similar follow-up times (6.6 years in cemented group vs. 6.7 years in uncemented group, P = .60). Moreover, the groups did not differ significantly in sex composition, age at the time of surgery, or preoperative Walch glenoid grade distribution. No patients required revision surgery. The 2 groups had similar preoperative range of motion, but patients in the uncemented group had greater follow-up forward flexion (P = .03), external rotation (P < .01), and lateral elevation (P = .03) than did patients in the cemented group. PROMIS scores were not significantly different between groups. American Shoulder and Elbow Surgeons scores were similar (89.8 in cemented group vs. 94.1 in uncemented group, P = .21). Mid-term radiographs showed a metal debris rate of 24% in the cemented group and 27% in the uncemented group. Although these values were not significantly different (P = .90), the frequency of mild metal debris (grade 1-2), when present, was greater in the uncemented group (grade 2 in 6 shoulders) than in the cemented group (grade 1 in 4 and grade 2 in 1, P = .02). There was a greater presence of mild (grade 1) radiolucent lines in the uncemented group (64%) than in the cemented group (29%, P < .01). No glenoid had evidence of loosening (defined by a change in position or radiolucent lines > 2 mm). The presence of metal debris and radiolucent lines did not have a significant effect on clinical outcomes. CONCLUSION: At minimum 5-year follow-up, TSA patients with TM glenoids demonstrated excellent clinical and patient-reported outcomes with a 100% implant survival rate, regardless of cemented vs. uncemented fixation. However, the uncemented group showed a significantly higher rate of radiolucent lines and a higher frequency of mild metal debris. These radiographic findings did not affect the clinical outcomes, and their implications for long-term outcomes and prosthesis survival is unknown.

Trabecular Metal Cones Combined With Short Cemented Stem Allow Favorable Outcomes in Aseptic Revision Total Knee Arthroplasty.

BACKGROUND: The purpose of this study was to compare the functional outcomes and implant survivorship at a minimum of 5 years of follow-up of several reconstruction techniques with or without metaphyseal cone and stems of variable length. METHODS: A retrospective comparative matched analysis was performed from 2 prospectively collected databases. Only patients who underwent revision total knee arthroplasty procedures for aseptic causes using a single design of rotating hinge knee with a minimum of 5 years of follow-up were analyzed. Patients were separated into 3 groups: trabecular metal (TM) cones + short cemented stems (TM + short stem [SS]), TM cones + long uncemented stems (TM + long stem [LS]), and no cone (NC) + long uncemented stems (NC + LS). A matching process based on age (±5 years) was realized. RESULTS: About 99 patients were included; 33 in the TM + SS group, 33 in the TM + LS group, and 33 in the NC + LS group. The mean time of follow-up was 9.3 years. A significant difference of the improvement of subscale pain, symptom, activities of daily living, quality of life of the Knee Injury and Osteoarthritis Outcome score and knee, function of the Knee Society Score was observed in favor of TM + SS group compared with the 2 other groups. At 8 years of survivorship, the components free of revision for any cause were 90.9% for the TM + SS group, 84.9% for the TM + LS group, and 90.6% for the NC + LS group. CONCLUSION: The use of a short cemented tibial stem combined with a TM cone in revision total knee arthroplasty offers identical survival rate with better functional outcome compared with the use of a long uncemented stem associated with TM cones or metallic augments at a minimum of 5 years of follow-up.

Trabecular Metal Augments for Severe Acetabular Defects in Revision Hip Arthroplasty: A Long-Term Follow-Up.

BACKGROUND: Paprosky type IIIa and IIIb acetabular defects remain technically challenging during revision hip arthroplasty. Numerous surgical options exist to counter extensive acetabular bone loss with high postoperative complication and revision rates reported. Our aim was to report comprehensive long-term outcomes of our experience with Trabecular Metal (TM) augments for these difficult cases. METHODS: 38 patients underwent revision total hip arthroplasty at our institution from 2009 to 2014 where a TM augment was used for acetabular deficiency. Prospective radiographic and Patient-Reported Outcome Measures were recorded and analyzed to a mean of 7.3 years (range: 5.4 to 10.8). RESULTS: No patient was excluded or lost to follow-up. Complications included 3 intraoperative fractures, 1 early infection requiring washout with implant retention, 1 early revision due to allograft resorption, and 6 patients who required late repeat revision surgery: 3 for late infection, 2 for aseptic loosening with augment fracture or dislocation, and 1 for recurrent dislocation. The estimated mean implant survivorship was 8.99 years. 93.5% of augments remaining were well osseointegrated while 97% of the acetabular shells were osseointegrated. Hip center of rotation was restored by a mean of 14 mm inferiorly without significant medialization. Short Form-12 (SF-12) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were significantly reduced postoperatively to a level comparable to the average individual. CONCLUSION: This long-term study details our experience of TM augments for the most severe acetabular defects. For such cases, no excellent surgical solution exists; in comparison to alternative methods, we advocate that this technique is reasonably safe and effective.

Medium term clinical outcomes of tibial cones in revision knee arthroplasty.

INTRODUCTION: Trabecular metal cones are a relatively new option for reconstruction of major bone defects during revision total knee arthroplasty (TKA). The purpose of the present study was to retrospectively assess medium-term results for tibial cones in revision TKA with a severe proximal tibial bone defect. We hypothesized that revision TKA patients with bone defects treated with trabecular metal cones have excellent medium-term clinical and radiological results. PATIENTS AND METHODS: A single-center retrospective review included all consecutive cases of tibial revision using trabecular metal cones. All patients with a minimum 2-year follow-up were included in the study. There were no exclusion criteria. The primary endpoint was tibial cone survivorship. The secondary endpoints were revision TKA all-cause survivorship, patient-reported outcome measures with a Knee injury and Osteoarthritis Outcome Score (KOOS), SF 12, and radiographic analysis. RESULTS: Five of the 57 patients alive at last follow-up (8.77%) had undergone revision (4 for infection and 1 for instability). Complications comprised four cases (7.02%) of infection, 2 cases (3.51%) of tibial and femoral implant aseptic loosening that did not require revision surgery, 1 of which (1.75%) with associated patellar loosening, and 1 case (1.75%) of instability. Kaplan-Meier estimates showed 100% 5-year survivorship with tibial cone revision for aseptic loosening and 93.44% (95% CI 83.47-97.49%) for all-cause revision. DISCUSSION: The present study of cones used for tibial revision supports shows excellent results; however, longer and larger follow-up is needed to better assess results in revision TKA. LEVEL OF EVIDENCE: 4, retrospective study.

Bone impaction grafting with trabecular metal augments in large defects in young patients: unravelling a new perspective in surgical technique.

BACKGROUND: Acetabular reconstruction with bone impaction grafting in large defects has yielded conflicting results. METHODS: This was a retrospective study of a case series of five patients with a young age (≤50 years) at the time of surgery who had large acetabular defects reconstructed by bone impaction grafting and trabecular metal augments. The mean follow-up was 79 months. We describe the surgical technique in detail. RESULTS: Improvement was significant on the WOMAC and SF-36 scales (p < 0.05). The radiographs taken at the last follow-up examination showed no migration of the polyethylene cup (p = 0.31) or differences in the abduction angle (p = 0.27) compared to the radiographs from the immediate postoperative period. One patient presented two dislocation episodes as a complication. CONCLUSION: The combination of trabecular metal augments with the bone impaction grafting technique in young patients with large acetabular defects provides satisfactory results in the long term and restores the bone stock.

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.

To Cement or Not? Five-Year Results of a Prospective, Randomized Study Comparing Cemented vs Cementless Total Knee Arthroplasty.

BACKGROUND: The optimal mode of fixation in total knee arthroplasty is a continuing subject of debate. METHODS: Previously, we reported 2-year results for this prospective, randomized trial. Knee Society Scores, Oxford scores, and pain visual analog scales were collected pre-operatively and post-operatively. Minimum 5-year follow-up has been obtained with radiographic analysis for 85 patients. RESULTS: Mean Knee Society Scores and Oxford scores and patient-reported outcomes were similar in both groups. Each group had 1 additional revision, but neither was related to implant fixation. Survivorship with revision as an endpoint was equivalent (95.9% and 95.3%, P = .98). There was no significant difference in radiolucencies observed between groups (P = .10), all were non-progressive. CONCLUSION: Cementless and cemented total knee arthroplasty had equivalent patient-reported outcomes and survivorship at midterm follow-up. Updates are planned at 10 and 15-year intervals to observe long-term modes of failure between these 2 methods of fixation.

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.

New bone formation and trabecular bone microarchitecture of highly porous tantalum compared to titanium implant threads: A pilot canine study.

AIM: This study evaluated new bone formation activities and trabecular bone microarchitecture within the highly porous region of Trabecular Metal™ Dental Implants (TM) and between the threads of Tapered Screw-Vent® Dental Implants (TSV) in fresh canine extraction sockets. MATERIALS AND METHODS: Eight partially edentulated dogs received four implants (4.1 mmD × 13 mmL) bilaterally in mandibular fresh extraction sockets (32 TM, 32 TSV implants), and allowed to heal for 2, 4, 8, and 12 weeks. Calcein was administered to label mineralizing bone at 11 and 4 days before euthanasia for dogs undergoing all four healing periods. Biopsies taken at each time interval were examined histologically. Histomorphometric assay was conducted for 64 unstained and 64 stained slides at the region of interest (ROI) (6 mm long × 0.35 mm deep) in the midsections of the implants. Topographical and chemical analyses were also performed. RESULTS: Histomorphometry revealed significantly more new bone in the TM than in the TSV implants at each healing time (p = .0014, .0084, .0218, and .0251). Calcein-labeled data showed more newly mineralized bone in the TM group than in the TSV group at 2, 8, and 12 weeks (p = .045, .028, .002, respectively) but not at 4 weeks (p = .081). Histologically TM implants exhibited more bone growth and dominant new immature woven bone at an earlier time point than TSV implants. The parameters representing trabecular bone microarchitecture corroborated faster new bone formation in the TM implants when compared to the TSV implants. TM exhibited an irregular faceted topography compared to a relatively uniform microtextured surface for TSV. Chemical analysis showed peaks associated with each implant's composition material, and TSV also showed peaks reflecting the elements of the calcium phosphate blasting media. CONCLUSIONS AND CLINICAL IMPLICATIONS: Results suggest that the healing pathway associated with the highly porous midsection of TM dental implant could enable faster and stronger secondary implant stability than conventional osseointegration alone; however, prospective clinical studies are needed to confirm these potential benefits in patients with low bone density, compromised healing, or prior implant failure.

Total hip arthroplasty following failure of tantalum rod implantation for osteonecrosis of the femoral head with 5- to 10-year follow-up.

BACKGROUND: Total hip arthroplasty (THA) with failure of tantalum rod implant for osteonecrosis of the femoral head (ONFH) will be the only choice for patients. However,it remains unknown whether tantalum rod implantation has an adverse effect on the survival time of implants following conversion to THA. The aim of this study was to retrospectively evaluate the clinical and radiographic outcomes of conversion to THA in patients who were previously treated with implantation of a tantalum rod. METHODS: This study included 31 patients (39 hips), who underwent conversion to THA due to failure of core decompression with an implanted tantalum rod. Among these 31 patients, 26 patients were male and five patients were female. The mean age of these patients was 49.3 years old (range: 36-64 years old). The control group included 33 patients (40 hips), who underwent total hip replacement without tantalum rod implantation. The hip Harris score, implant wear, osteolysis, radiolucencies and surgical complications were recorded during the follow-up. The distribution of tantalum debris in the proximal, middle and distal periprosthetic femoral regions, radiolucent lines and osteolysis were analyzed on post-operative radiographs. RESULTS: There were no significant differences in Harris score, liner wear and complications between the two groups (P > 0.05). Osteolysis and radiolucent lines more likely occurred in patients with tantalum debris distributed in three regions than in one or two regions (P < 0.05). CONCLUSIONS: The mid-term clinical outcome of patients who underwent THA with tantalum rod implantation was not different from those without a tantalum rod, suggesting that tantalum debris did not increase the liner wear rate. However, the distribution of periprosthetic tantalum debris in the proximal, middle and distal femoral regions may increase the risk of femoral osteolysis and radiolucent lines.

Outcomes of Trabecular Metal-backed glenoid components in anatomic total shoulder arthroplasty.

BACKGROUND: As glenoid failure is one of the primary causes of failure of anatomic total shoulder arthroplasty (TSA), Trabecular Metal-backed glenoid components have become popular. This study reports implant survival and clinical outcomes of patients who received a Trabecular Metal-backed glenoid component during primary anatomic TSA. METHODS: Patients who underwent TSA with a Trabecular Metal-backed glenoid component by a single surgeon were identified and reviewed for clinical, radiographic, and patient-reported outcome measures with a minimum of 2 years' follow-up. RESULTS: Of 47 patients identified, radiographic and clinical follow-up was available on 36 patients (77%). Average age was 66.36 years (range, 50-85 years), and the average follow-up 41 months (range, 24-66 months). Three patients showed signs of osteolysis, 4 had radiographic evidence of metal debris, and 1 patient had a catastrophic failure after a fall. Of the 47 TSAs, 5 (11%) were revised to a reverse TSA for subscapularis failure and pain. Visual analog scale for pain scores improved by an average of 4.4. At final follow-up, the average Single Assessment Numeric Evaluation score was 72.4; Penn satisfaction score, 7.5; Penn score, 70.35; and American Shoulder and Elbow Surgeons score, 69.23. Outcome scores were similar in the 7 patients with osteolysis or metal debris compared to those without. CONCLUSION: Trabecular Metal-backed glenoids had a 25% rate of radiographic metal debris and osteolysis at a minimum 2-year follow-up in this series with one catastrophic failure. This implant should be used with caution, and patients followed closely.

Trabecular Metal Acetabular Components Reduce the Risk of Revision Following Primary Total Hip Arthroplasty: A Propensity Score Matched Study From the National Joint Registry for England and Wales.

BACKGROUND: Trabecular metal (TM)-coated acetabular components are increasingly used in both primary and revision total hip arthroplasty (THA). However, previous studies assessing TM acetabular components have been small single-center cohorts with most lacking a control group. We compared revision rates following primary THA between TM and non-TM-coated acetabular components. METHODS: A retrospective observational study was performed using National Joint Registry data, which included primary THAs with the same cementless acetabular component (either TM or non-TM coated). TM and non-TM implants were matched for multiple potential confounding factors using propensity scores. Outcomes following primary THA (revision for all-cause acetabular indications, aseptic acetabular loosening, and infection) were compared between matched groups using competing risk regression analysis. RESULTS: In 18,200 primary THAs (9100 TM and 9100 non-TM), the overall prevalence of acetabular revision, revision for aseptic acetabular loosening, and septic revision was 1.2%, 0.13%, and 0.59% respectively. Five-year revision rates for all-causes (1.0% vs 1.8%, sub-hazard ratio [SHR] 0.57, 95% confidence interval [CI] 0.43-0.76, P < .001), aseptic acetabular loosening (0.1% vs 0.2%, SHR 0.35, 95% CI 0.14-0.90, P = .029), and infection (0.5% vs 0.9%, SHR 0.51, 95% CI 0.34-0.76, P = .001) were all lower in TM compared with non-TM implants. CONCLUSION: Following primary THA, TM-coated acetabular implants had a reduced risk of both aseptic and septic revision compared with non-TM implants. Although absolute differences in revision risk were small, they may be clinically significant if TM designs were implanted in more complex cases.