Aim. We present the medium-term clinical results of a reverse total shoulder arthroplasty with a trabecular metal glenoid base plate. Patients and Methods. We reviewed 125 consecutive primary reverse total shoulder arthroplasties (RTSA) implanted in 124 patients for rotator cuff arthropathy. There were 100 women and 24 men in the study group with a mean age of 76 years (58 to 89). The mean follow-up was 32 months (24 to 60). No patient was lost to follow-up. Results. There were statistically significant improvements in the mean range of movement and Oxford Shoulder Score (p < 0.001). Kaplan-Meier survivorship at five years was 96.7% (95% confidence interval 91.5 to 98.7) with aseptic glenoid failure as the end point. . Radiologically, 63 shoulders (50.4%) showed no evidence of notching, 51 (40.8%) had grade 1 notching, ten (8.0%) had grade 2 notching and one (0.8%) had grade 4 notching. Radiolucency around the glenoid base plate was found in one patient (0.8%) and around the humeral stem in five (4.0%). In all, three RTSA (2.4%) underwent revision surgery for aseptic mechanical failure of the glenoid within 11 months of surgery due to malseating of the glenosphere. Conclusion. The clinical results of this large independent single unit series are comparable to those from previous series of RTSA reported in the literature. A trabecular metal base plate is safe and effective in the medium-term. Cite this article: Bone Joint J 2016;98-B:969–75

Aims. The advent of trabecular metal (TM) augments has revolutionized the management of severe bone defects during acetabular reconstruction. The purpose of this study was to evaluate patients undergoing revision total hip arthroplasty (THA) with the use of TM augments for reconstruction of Paprosky IIIA and IIIB defects. Patients and Methods. A retrospective study was conducted at four centres between August 2008 and January 2015. Patients treated with TM augments and TM shell for a Paprosky grade IIIA or IIIB defect, in the absence of pelvic discontinuity, and who underwent revision hip arthroplasty with the use of TM augments were included in the study. A total of 41 patients with minimum follow-up of two years were included and evaluated using intention-to-treat analysis. Results. There were 36 (87.8%) patients with a Paprosky IIIA defect and five (12.2%) patients with a Paprosky IIIB defect. The mean age was 56.7 years (28 to 94). There were 21 (51.2%) women and 20 (48.8%) men. The mean follow-up was 39.4 months (12 to 96). One (2%) patient died after eight years. No failures were noted in the series. The mean survivorship was 100% at the time of latest follow-up. Conclusion. The results of this multicentre study showed encouraging short- and mid-term results for the use of TM augments in the management of Paprosky grade IIIA and IIIB defects. Cite this article: Bone Joint J 2018;100-B:903–8

Trabecular metal (TM) augments are a relatively new option for reconstructing segmental bone loss during acetabular revision. We studied 34 failed hip replacements in 34 patients that were revised between October 2003 and March 2010 using a TM acetabular shell and one or two augments. The mean age of the patients at the time of surgery was 69.3 years (46 to 86) and the mean follow-up was 64.5 months (27 to 107). In all, 18 patients had a minor column defect, 14 had a major column defect, and two were associated with pelvic discontinuity. The hip centre of rotation was restored in 27 patients (79.4%). The Oxford hip score increased from a mean of 15.4 points (6 to 25) before revision to a mean of 37.7 (29 to 47) at the final follow-up. There were three aseptic loosenings of the construct, two of them in the patients with pelvic discontinuity. One septic loosening also occurred in a patient who had previously had an infected hip replacement. The augments remained stable in two of the failed hips. Whenever there was a loose acetabular component in contact with a stable augment, progressive metal debris shedding was evident on the serial radiographs. Complications included another deep infection treated without revision surgery. Good clinical and radiological results can be expected for bone-deficient acetabula treated by a TM cup and augment, but for pelvic discontinuities this might not be a reliable option. Cite this article: Bone Joint J 2013;95-B:166–72

Shoulder arthroplasty has experienced exponential growth in the past 10–15 years, largely due to improvements in anatomical design, increased application of technology to address various clinical pathology, and improved access to experienced shoulder surgeons. Glenohumeral arthritis has historically been the most common indication for a shoulder replacement, and glenoid wear has been the main concern with regards to longevity of the prosthesis. Attempts to improve glenoid components involve alterations in peg or keel configuration, as well as the introduction of metal backed constructs. Early experience with metal backed components led to very poor results with often catastrophic loosening and destruction of glenoid bone. Proximal humerus fractures are another common indication for a shoulder arthroplasty, and in these cases, tuberosity fixation and healing are the challenge precluding a consistently successful result. More recently, base plate fixation in the setting of a reverse shoulder arthroplasty has come to the forefront as a significant factor. Trabecular metal technology has emerged as a compelling method of enabling powerful bone ingrowth to the surfaces of arthroplasty components. Trabecular metal is composed of tantalum. It is used to form a carbon scaffold which has a modulus between that of cancellous and cortical bone, thus has some flexibility when made into an independent construct. Vapor deposition onto arthroplasty surfaces provides a bone ingrowth surface. There is interest in utilizing trabecular metal for glenoid and tuberosity fixation in particular. Trabecular metal proximal coated stems provide an ingrowth surface for tuberosity fixation in the setting of proximal humerus fractures. Long term results are still pending. Because the metal is much less stiff then other metals, trabecular metal has recently been used along the back of polyethylene glenoids. The original design had a problem with fracture at the base of the pegs. A redesigned component instituting a cruciate design was implemented, and is currently available on a limited release basis with promising early results. The use of trabecular metal on the deep surface of the reverse arthroplasty baseplate and the proximal aspect of the reverse stem has led to successful fixation, allowing cementless fixation of both the humeral and glenoid components. Learning objectives of this presentation include:. Understand the mechanical characteristics of trabecular metal and its bone ingrowth characteristics. Familiarize with currently available prosthetics incorporating trabecular metal technology. Case presentations utilizing trabecular metal coated components

The indications for cementless acetabular fixation have been broadened because our data supports the use of trabecular metal cups even when there's limited bleeding host bone contact. Trabecular metal augments have allowed us to use cementless cups when there is segmental loss of bone. Surgical Technique: The acetabular bed is prepared. If there is less medial bone stock than 2 mm, then morselised allograft is impacted by reverse reaming. When reaming is complete and less than 50% bleeding host bone is available for cup stabilization, then a trabecular metal cup is indicated. Trabecular augments are used if the trabecular cup trial is not stable, or if it is uncovered by 40% or more. The conventional augments come in different sizes to accommodate the diameter of the cup and the size of the defect. Larger defects are addressed with anterior and posterior column augments, and superior defects with figure of seven augments. Augments are fixed with at least two screws. The interface between the cup and the augments should be stable, but some surgeons place a very thin layer of cement between the augment and cup so micromotion does not occur while ingrowth is occurring. We have used trabecular metal augments in 46 acetabular revisions in conjunction with a trabecular metal cup. Thirty-four cases have at least 2 years follow-up with an average of 64.5 months. There has been 4 cup loosenings with 3 re-revisions

The indications for cementless acetabular fixation have been broadened because our data supports the use of trabecular metal cups even when there's limited bleeding host bone contact. Trabecular metal augments have allowed us to use cementless cups when there is segmental loss of bone. Surgical Technique: The acetabular bed is prepared. If there is less medial bone stock than 2mm, then morselised allograft is impacted by reverse reaming. When reaming is complete and less than 50% bleeding host bone is available for cup stabilisation, then a trabecular metal cup is indicated. Trabecular augments are used if the trabecular cup trial is not stable, or if it is uncovered by 40% or more. The conventional augments come in different sizes to accommodate the diameter of the cup and the size of the defect. Larger defects are addressed with anterior and posterior column augments, and superior defects with figure of seven augments. Augments are fixed with at least two screws. The interface between the cup and the augments should be stable, but some surgeons place a very thin layer of cement between the augment and cup so micromotion does not occur while ingrowth is occurring. We have used trabecular metal augments in 46 acetabular revisions in conjunction with a trabecular metal cup. Thirty-four cases have at least 2 years follow-up with an average of 64.5 months. There have been 4 cup loosenings with 3 re-revisions

Purpose. The aim of this study was to compare the clinical outcomes of the revision TKA in which trabecular metal cones and femoral head allografts were used for large bone defect. Method. Total 53 patients who have undergone revision TKA from July 2013 to March 2017 were enrolled in this study. Among them, 24 patients used trabecular metal cones, and 29 patients used femoral head allografts for large bone defect. There were 3 males and 21 females in the metal cone group, while there were 4 males and 25 females in the allograft group. The mean age was 70.2 years (range, 51–80) in the femoral head allograft group, while it was 79.1 years (range, 73–85) in the metal cone group. Bone defect is classified according to the AORI classification and clinical outcomes were evaluated with Visual Analogue Scale (VAS), Hospital Special Surgery-score (HSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and ROM. Operation time was also evaluated. We used radiographs to check complications such as migration or loosening. We took follow-up x-rays and 3D CT of the patients, to assess the mean bone union period. Shapiro-Wilk test was done to check normality and Student T-test and Mann Whitney U-test were done for comparison between two groups. Result. The mean follow-up period was 3 .75 years (Range; 2.1 ∼ 5.75). The pre-op scores did not show significant difference. The mean VAS in the allograft and trabecular metal cone groups was 2.1 ± 0.87 and 1.8 ± 0.53, respectively (p = 0.16). The mean HSS score were 76.3 ± 5.51 and 79.2 ± 4.12 respectively (p = 0.13) and the mean WOMAC scores were 15.1 ± 3.25 and 14.8 ± 3.31 respectively (p = 0.06), and the mean KOOS scores were 27.8 ± 4.77 and 25.5 ± 4.84, respectively (p = 0.07). The mean ROM ranges were 100.6 ± 17.54 and 101.3 ± 19.22, respectively (p = 0.09). But the mean operation time of the allograft and trabecular metal cone groups was 137 minutes (Range; 111–198) and 102minutes (Range; 93 −133) (p=0.02) respectively, which showed statistical significance. In follow-up x-rays, no migration or loosening of the implants, osteolysis and other complications were found in both groups. In follow-up 3D CT, osteointegration was seen at the trabecular metal cone site, host bone being interpreted to the host bone. The allograft group showed fibrous and stable union in follow-up 3D CT. Conclusion. According to this study, in case of revision TKA with large bone defect, using whether allograft or trabecular metal cones did not affect the clinical outcomes. However, operation time was significantly shorter in trabecular metal cone group, therefore, in patients with poor general condition along with severe underlying diseases, usage of trabecular metal cone would be a better choice to shorten operation time and ease postoperative care. Keywords. Revision TKA, metal cone, allograft, bone defect. For any figures or tables, please contact authors directly

We compared the performance of uncemented trabecular metal tibial components in total knee replacement with that of cemented tibial components in patients younger than 60 years over two years using radiostereophotogrammetric analysis (RSA). A total of 22 consecutive patients (mean age 53 years, 33 to 59, 26 knees) received an uncemented NexGen trabecular metal cruciate-retaining monobloc tibial component and 19 (mean 53 years, 44 to 59, 21 knees) a cemented NexGen Option cruciate-retaining modular tibial component. All the trabecular metal components migrated during the initial three months and then stabilised. The exception was external rotation, which did not stabilise until 12 months. Unlike conventional metal-backed implants which displayed a tilting migration comprising subsidence and lift-off from the tibial tray, most of the trabecular metal components showed subsidence only, probably due to the elasticity of the implant. This pattern of subsidence is regarded as being beneficial for uncemented fixation

The indications for cementless acetabular fixation have been broadened because our data supports the use of trabecular metal cups even when there's limited bleeding host bone contact. Trabecular metal augments have allowed us to use cementless cups when there is segmental loss of bone. Surgical Technique: The acetabular bed is prepared. If there is less medial bone stock than 2 mm, then morselised allograft is impacted by reverse reaming. When reaming is complete and less than 50% bleeding host bone is available for cup stabilization, then a trabecular metal cup is indicated. Trabecular augments are used if the trabecular cup trial is not stable, or if it is uncovered by 40% or more. The conventional augments come in different sizes to accommodate the diameter of the cup and the size of the defect. Larger defects are addressed with anterior and posterior column augments, and superior defects with figure of seven augments. Augments are fixed with at least two screws. The interface between the cup and the augments should be stable, but some surgeons place a very thin layer of cement between the augment and cup so micromotion does not occur while ingrowth is occurring. We have used trabecular metal augments in 46 acetabular revisions in conjunction with a trabecular metal cup. Thirty-four cases have at least 2 years follow-up with an average of 64.5 months. There has been 4 cup loosenings with 3 re-revisions. Our most up to date data is 101 cases with an average follow-up of 3 years. There has been one infection that underwent a two stage revision. There are 4 loose cups – 3 revised

The indications for cementless acetabular fixation have been broadened because our data supports the use of trabecular metal cups even when there's limited bleeding host bone contact. Trabecular metal augments have allowed us to use cementless cups when there is segmental loss of bone. Surgical Technique:. The acetabular bed is prepared. If there is less medial bone stock than 2mm, then morselised allograft is impacted by reverse reaming. When reaming is complete and less than 50% bleeding host bone is available for cup stabilization, then a trabecular metal cup is indicated. Trabecular augments are used if the trabecular cup trial is not stable, or if it is uncovered by 40% or more. The conventional augments come in different sizes to accommodate the diameter of the cup and the size of the defect. Larger defects are addressed with anterior and posterior column augments, and superior defects with figure of seven augments. Augments are fixed with at least two screws. The interface between the cup and the augments should be stable, but some surgeons place a very thin layer of cement between the augment and cup so micromotion does not occur while ingrowth is occurring. We have used trabecular metal augments in 46 acetabular revisions in conjunction with a TM cup. Thirty-four cases have at least 2 years follow-up with an average of 64.5 months. There has been 4 cup loosenings with 3 re-revisions

The authors studied the short-term results following patellar resurfacing using trabecular metal patella. Ten patients underwent primary (2 cases) or revision (8 cases) TKA with the use of a trabecular metal patella and were evaluated at a mean follow-up of 24 months. All patients had marked patellar bone deficiency or patellar absence precluding resurfacing with a standard cemented patellar button. The all polyethylene patella was cemented into the trabecular metal base and the remaining patella bone stock; additional fixation was provided by non-adsorbable sutures through the peripheral holes on the metal shell. No intraoperative complications occurred. There was no displacement of any trabecular metal patellar component and no patellar fractures. The fixation appeared excellent at three to six months radiographic evaluation with uniform bone contact in the peripheral regions in both lateral an Merchant radiographic views. The mean Knee Society scores improved in all patients

Purpose. A Trabecular Metal Modular Acetabular System (Zimmer, Warsaw, Indiana, USA) is a peripheral rim expansion (elliptical) cup, i.e. a non-hemispherical cup. Radiologically a non-hemispherical cup may be deferent from other conventional hemispherical cups. We reviewed radiological findings of a Trabecular Metal Modular Acetabular System chronologically. Methods. Twenty six patients with osteoarthritis underwent primary total hip arthroplasty (THA) using a Trabecular Metal Modular Acetabular System from 2011 to April 2013. Twenty five patients (follow-up rate: 96.2%) 31 hips could be followed-up over a year were registered. In common, the diameter of every femoral head was 32 mm. We planned the acetabular cup inclination angle to be 45-degree, the cup coverage with host-bone (cup-CE angle) to be over 10-degree, and high hip center was allowed up to 20mm. In case of the cup-CE angle under 10-degree, an acetabular cup was placed medially using Dorr's medial protrusio technique. We established the medial protrusion angle indicating the degree of medial protrusion of an acetabular cup over the pelvic internal wall. The medial protrusion angle was defined by the center point of THA (C) and the 2 cross-points (X. 1. , X. 2. ) which the outline of an acetabular cup crosses the Kohler's line (Figure 1). The cup anteversion angle was measured by the method of Lewinnek, and the cup fixation was evaluated according to the Tompkin's classification. Results. The average follow-up period was 1 year and 3 months (1y1m to 2y8m). The mean diameter of the cup was 54 (48 to 56) mm. Seven high-hip center joints were recognized (2 to 11 mm). The average of cup inclination angle was 42 (32 to 52) degree, of cup anteversion angle was 14 (5 to 36) degree, and of cup CE angle was 25 (−14 to 45) degree. Dorr's medial protrusio technique was necessary in 18 hips. In these 18 hips, the average of medial protrusion angle was 57 (24 to 70) degree. In 4 hips of cup-CE angle less than 10 degree, acetabular bulky bone graft was added. All 31 hips showed the stable fixation, even in 18 hips undergone medial protrusio technique. There was none of hips with migration and/or rotation of an acetabular cup. Radiolucent zone was found in the zone-C of 8 hips. The width of radiolucent zone of all 8 hips was less than 2mm. In these 8 hips, medial protrusio technique was done in 5 hips, and high hip center was found in 3 hips. The radiolucency appeared at postoperatively 2–3 months and disappeared by postoperatively 12 months. Conclusions. All hips showed rigid fixation of a Trabecular Metal Modular Acetabular System in short-term observation. Even in the hips performed Dorr's medial protrusio technique, a Trabecular Metal Modular Acetabular System reached the stable fixation. Radiolucent zone was found transiently in the zone-C of 8 hips (25.8%) and disappeared by postoperatively 12 months. However our series was small and the observation period was short, our results implied that the fixation of a Trabecular Metal Modular Acetabular System was not affected adversely from Dorr's medial protrusio technique

Introduction. Acetabular component loosening with associated bone loss is a challenge in revision hip arthroplasty. Trabecular Metal (TM) by Zimmer Biomet has been shown to have greater implant survivorship for all-cause acetabular revision in small cohort retrospective studies. Our study aims to review outcomes of acetabular TM implants locally. Method. This is a retrospective observational study using data from Auckland City and North Shore Hospitals from 1st of January 2010 to 31st of December 2020. Primary outcome is implant survivorship (re-revision acetabular surgery for any cause) demonstrated using Kaplan-Meier analysis. Secondary outcome is indication for index revision and re-revision surgery. Multivariate analysis used to identify statistically significant factors for re-revision surgery. Results. 225 cases used acetabular TM implants (shells and/or augments) over 10 years. Indications include aseptic loosening (63%), instability (15%) and infection (13%). Of these, 12% (n=28) had further re-revision for infection (54%) and instability (21%). Median time to re-revision was 156 days (range 11 – 2022). No cases of re-revision were due to failure of bony ingrowth or acetabular component loosening. Ethnicity, smoking status, and age were not risk factors for re-revision procedures. Additionally, previous prosthetic joint infection, ethnicity, sex and age were not significant risk factors for re-revision due to infection. Implant survivorship was 80% at 1 year, 71% at 5 years and 64% at 10 years. Discussion. Main indications for re-revision were infection and instability. Demographic factors and co-morbidities did not correlate with increased re-revision risk. Survivorship is poorer compared to cumulative survivorship reported by the New Zealand Joint Registry (NZJR). Explanations are multifactorial and possibly contributed by underestimation of true revision rates by registry data. Conclusions. We need to identify alternate causes for poorer survivorship and review the role of TM implants in acetabular revision within our specified population

Although total hip arthroplasty is highly successful for treatment of osteoarthrosis of hip joint, it is skill demanding surgery to perform and even more challenging in case of revision with bone defects. There are many options available for reconstruction of acetabular bony defects. Here, we evaluate the outcome of acetabular bony defect reconstructed with trabecular metal augments in short term. We performed, 22 revision total hip arthroplasties and 6 primary total hip arthroplasties (total 28 in 28 patients) using trabecular metal augments to reconstruct acetabular defect between 2011 to 2015. Out of these 28 patients, 18 were males and 10 were females. Mean age of these patients was 61.2 years (range: 46 years to 79 years). Pre-operative templating was done for all cases and need for trabecular metal augments was anticipated in all cases. All cases were classified according to Paprosky classification for acetabular bone defects. Out of 28 patients, 3 had type 2B, 1 had type 2C, 18 had type 3A and 6 had type 3B acetabular defects. Post operatively, all patients were followed at regular interval for their clinical and radiological outcome. An average follow up was 20.1 months (range: 6 months to 42.5 months). We assessed clinical outcome in the form of Herris hip score (HHS) and radiological outcomes in form of osteolysis in acetabular zones and osseointegration, according to the criteria of Moore. The average Harris hip score (HHS) was improved from 58.0 preoperatively to 87.2 postoperatively. The average degree of cup abduction at the final follow up was 44.29. The centre of rotation of the hip joint was corrected from average 38.90mm (range: 22.15mm to 66.35mm) above the inter-teardrop line preoperatively to average 23.85mm (range: 11.82mm to 37.69mm) above the inter-teardrop line postoperatively. Out of 28 patients, 18 patients had three or more signs of osseointegration, according to the criteria of Moore, at the time of final follow up. Rest of patients, had one or two signs of osseointegration (5 patients had one sign and 5 patients had two signs). We had no patient with migration or loosening of acetabular components. No patient has osteolysis of acetabulum in any zone. Trabecular metal augments provide good initial stability to acetabular cup as well as helpful to bring down the centre of rotation of the hip joint within limit of 35mm above the inter-teardrop line. They also facilitate osseointegration. Our study showed that the results of the trabecular metal augments in reconstruction of acetabular bony defects were successful even in short term. However, long term study is required for better evaluation

Introduction: It is desirable to delay or avoid total joint replacement in young patients who have osteonecrosis of femoral head. There are some head preserving surgical procedures that attempt this including osteotomy, core decompression, and bone grafting. The vascularized fibular graft has been reported to be a reliable procedure, but unfortunately it has donor site morbidity and is considered technically demanding. Therefore, materials have been developed to substitute for structural fibular graft. New trabecular metal has been developed to be used for osteonecrosis of femoral head. The purpose of this study was to review the clinical outcomes of trabecular metal as a treatment intervention method for osteonecrosis of the femoral head. Materials and Methods: Seven patients (8 hips) with osteonecrosis of femoral head received core decompression and a trabecular metal implant, beginning in March 2003. The stage of osteonecrosis was I or II according to Ficat and Arlet except for one case (stage III). The procedure consists of a core decompression and insertion of trabecular metal rod (porous tantalum, Zimmer Inc./ Implex Incorporation). A Harris Hip Score was obtained pre-operatively, and at three and at three and six months. Radiographic data was collected at the same time of clinical follow-up. Results: All 7 patients are doing well. Radiographic review shows no evidence of further femoral head collapse. Discussion: Even though this is short term follow-up, the authors propose that the use of trabecular metal in osteonecrosis patients is simple, safe, and effective for the salvage of the hip

Compromised patellar bone stock poses significant the chnical problems in primary and revision knee arthroplasty. In these situations, traditional approaches have included: non resurfacing, patellectomy, patellar bone grafting, ‘Gull-Wing’ osteotomy. A new material (Trabecular Metal) fabricated using a tantalum metal and vapor deposition techhnique that create a metallic strut configuration with 80%porosity, and physical and mechanical properties similar to bone has been introduced. The authors studied the short-term results following patellar resurfacing using trabecular metal patella in primary and revision total knee arhroplasty (TKA). Nine patients undergoing primary (2 cases) or revision (7 cases) TKA with the use of a trabecular metal patella were evaluated at a mean of 16 months follow-up. All patients had marked patellar bone deficiency precluding resurfacing with a standard cemented patellar button. The all polyethylene patela was cemented into the trabecular metal base and the remaining patella bone stock; additional fixation was provided by # 2 non absorbable sutures through the peripheral holes on the metal shell. Revision TKA may be complicated by severe patellar bone loss that preclude implantantion of a standard cemented patellar component. Several options including patellectomy, non resurfacing and osteotomy or grafting of remaining bony shell have been proposed. It is rare in primary knee arthroplasty that the patella has been so eroded that resurfacing is not feasible. Trabecular metall patella may be indicate in the complex revision or even primary knee arthroplasty in which all that remains of the patella is a thin shell of anterior cortical. The short-term results of patellar resurfacing with trabecular metal have demonstrated favorable results

Background. Synthetic interbody spinal fusion devices are used to restore and maintain disc height and ensure proper vertebral alignment. These devices are often filled with autograft bone to facilitate bone bridging through the device while providing mechanical stability. Nonporous polyetheretherketone (PEEK) devices are widely used clinically for such procedures. 1. Trabecular Metal devices are an alternative, fabricated from porous tantalum. It was hypothesized that the porous Trabecular Metal device would better maintain autograft viability through the center of the device, the ‘graft hole’ (GH). Methods. Twenty-five goats underwent anterior cervical discectomy and fusion using a Trabecular Metal or PEEK device for 6, 12 or 26 weeks. The GH of each device was filled with autograft bone morsels harvested from the animal at implantation. Fluorochrome labeling oxytetracycline was administered to the animals and used to determine bone viability in the device regions. Following necropsy, the vertebral segments were embedded in poly(methyl methacrylate) sectioned and analyzed using fluorescence and backscatter electron (BSE) imaging. The percent of bone tissue present within the GH was measured as a volume percent using BSE images (Fig. 1). Results. Bone percent analysis demonstrated that there was no significant difference (p<0.05) in volume of bone tissue within the GH of the two devices at 6 and 26 weeks (Fig. 2). At 12 weeks the animals implanted with the Trabecular Metal device had significantly greater volumes of bone within the GH region. Viable bone was observed in the host bone region and periprosthetic to the implant of all PEEK (n=12) and Trabecular Metal (n=12) animals within the study, determined by the presence of fluorescent labels (Fig. 3). Viable bone was also observed in the GH region of all animals with a Trabecular Metal device. However, only 5 of 12 PEEK animals showed bone viability within the GH (2 at 12 weeks and 3 at 26 weeks). A Fisher's exact comparison of the number of animals with viable bone in the GH showed a significant difference between the two devices, p<0.05. Conclusion. Autograft viability was better maintained within the GH for the porous Trabecular Metal device compared to the PEEK device. Although the amount of bone tissue within the GH of the PEEK devices was determined to have no significant difference compared to the Trabecular Metal devices at 6 and 26 weeks, the GH bone tissue was not viable in a number of the PEEK animals at each time point. The interconnected network and high volume porosity of the Trabecular Metal device may have allowed for fluid exchange, angiogenesis and increased blood supply to the autograft morsels. The viability of the autograft morsels also played an important role in the success of bone bridging through the GH between the vertebral endplates. In this animal model it was demonstrated that the autograft bone placed within the PEEK spinal fusion device did not always remain viable after implantation, but sometimes only filled the GH and did not necessarily facilitate fusion between the vertebrae as intended

Aims. Reverse total shoulder arthroplasty (RTSA) using trabecular metal (TM)-backed glenoid implants has been introduced with the aim to increase implant survival. Only short-term reports on the outcomes of TM-RTSA have been published to date. We aim to present the seven-year survival of TM-backed glenoid implants along with minimum five-year clinical and radiological outcomes. Methods. All consecutive elective RTSAs performed at a single centre between November 2008 and October 2014 were reviewed. Patients who had primary TM-RTSA for rotator cuff arthropathy and osteoarthritis with deficient cuff were included. A total of 190 shoulders in 168 patients (41 male, 127 female) were identified for inclusion at a mean of 7.27 years (SD 1.4) from surgery. The primary outcome was survival of the implant with all-cause revision and aseptic glenoid loosening as endpoints. Secondary outcomes were clinical, radiological, and patient-related outcomes with a five-year minimum follow-up. Results. The implant was revised in ten shoulders (5.2%) with a median time to revision of 21.2 months (interquartile range (IQR) 9.9 to 41.8). The Kaplan-Meier survivorship estimate at seven years was 95.9% (95% confidence interval (CI) 91.7 to 98; 35 RTSAs at risk) for aseptic mechanical failure of the glenoid and 94.8% (95% CI 77.5 to 96.3; 35 RTSAs at risk) for all-cause revision. Minimum five-year clinical and radiological outcomes were available for 103 and 98 RTSAs respectively with a median follow-up time of six years (IQR 5.2 to 7.0). Median postoperative Oxford Shoulder Score was 38 (IQR 31 to 45); median Constant and Murley score was 60 (IQR 47.5 to 70); median forward flexion 115° (IQR 100° to 125°); median abduction 95° (IQR 80° to 120°); and external rotation 25° (IQR 15° to 40°) Scapular notching was seen in 62 RTSAs (63.2%). Conclusion. We present the largest and longest-term series of TM-backed glenoid implants demonstrating 94.8% all-cause survivorship at seven years. Specifically pertaining to glenoid loosening, survival of the implant increased to 95.9%. In addition, we report satisfactory minimum five-year clinical and radiological outcomes. Cite this article: Bone Joint J 2021;103-B(8):1333–1338

The introduction of porous tantalum metal (Trabecular Metal; Zimmer, Warsaw, IN) for acetabular component fixation in total hip arthroplasty has shown optimum fixation qualities and “gap filling” effect. Recently, trabecular metal was introduced in tibial component for total knee prosthesis, however its effect on the bone mineral density (BMD) was not reported. The purpose of this study was to compare the BMD of proximal part of the tibia between trabecular metal and another cemented tibial component. 31 knees receiving trabecular metal tibial component and 33 knees receiving cemented tibial component (PFC Sigma RP, Depuy, Warsaw, IN) had dual energy x-ray absorptiometry (DEXA) scans at preoperatively and 3 weeks, 3, 6, 12, 18, 24 months post-operatively. To assess peri-prosthetic BMD, three regions of interest (ROI) were measured for each case. They were medial aspect (ROI 1), center aspect (ROI 2) and lateral aspect (ROI 3) of tibia. Average follow up period was 1.8 (range: 1.5 to 2) years. In both groups, BMD in tibia decrease postoperatively. Comparing postoperative decrease of BMD in lateral aspect of tibia (ROI 3) between both groups, it was significantly less in trabecular metal component (−0.09 g/cm2 +/−0.27) than cemented tibial component (−0.31 g/cm2 +/− 0.21) (p=0.0007). We conclude that trabecular metal tibial component showed a favorable effect on BMD of proximal part of the tibia after total knee arthroplsaty

Introduction: Porous Tantalum has been used in a variety of clinical settings since 1997. The use of trabecular metal backed prostheses and augments in the revision hip scenario is attractive due to the higher propensity of bony ingrowth than traditional porous coatings, and also the high coefficient of friction with bone leads to excellent press fit. We describe the early results of twenty trabecular metal backed acetabular components in the revision setting. Methods: From 2004, 20 patients received trabecular metal backed acetabular components as a revision hip procedure. The average age of the patients was 69 (42–84) yrs at the time of surgery. 4 patients had trabecular metal shells with cemented liners, 16 patients had modular trabecular metal implants. Structural allograft was used in 2 cases, trabcular metal augment in 1. Revision was for aseptic loosening in 17 cases, infection in 3. Acetabular defects were graded according to Paprosky as 2A(10), 2B(1), 2C(1), 3A(6) and 3B(2). Fixation was augmented in all cups with at least one screw. Patients were evaluated with standard x-rays for osteolysis and migration, Harris hip score, SF 36 and Oxford hip score. Results: Average follow up was 12 months (24–5). 100% follow up was achieved. There were no complications directly related to the acetabular surgery. There were no revisions. There are no progressive radiolucencies or detectable migration in any of the cups. There were no dislocations. Conclusion: These early results suggest that trabecular metal backed acetabular components may be confidently used in the setting of hip revision surgery and show promise for the more severe defects for which a reliably reproducible solution has yet to be proven