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

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

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

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

Purpose. To evaluate the five year Radiostereometric Analysis (RSA) results of the NexGen LPS Trabecular Metal Tibial Monoblock component (TM) and the NexGen Option Stemmed cemented component (Cemented), (Zimmer, Warsaw IN). Method. 70 patients with osteoarthritis were included in a randomized series to receive either the TM implant or the cemented NG component. Surgery was performed by high volume arthoplasty specialists using standardized procedure. RSA exams were obtained postoperatively, at six months, one year, two years and five years. RSA outcomes were translations, rotations and maximum total point motion (MTPM) of the components. MTPM values were used to classify implants as ‘at risk’ or ‘stable’. Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores were gathered at all follow-ups. An analysis of variance was used to test for differences in age, body mass index (BMI), and subjective measures between implant groups. The Kruskal-Wallis test was used to investigate differences in maximum total point motion between implant groups. An analysis of variance was used to test for differences in translations and rotations between groups. Fishers exact test was used to investigate differences in proportions of implants found to be at risk between groups. Results. At the five year follow-up, 43 patients were able to be reached and were willing to participate in the follow-up exam. There were 25 in the trabecular metal group and 18 in the cemented group. There were no differences in subjective measures (WOMAC) between implant groups at any follow-up. At the five year follow-up there was no difference in MTPM between the cemented and trabecular metal groups (p=0.94) Compared to the cemented components, the trabecular metal tibial components had significantly higher subsidence than the cemented components (p=0.001). There were no other significant differences. The proportion of at risk components at five years was 2 of 16 (0.11, 95% CI, 0.03–0.33) in the cemented group and was 0 of 25 (0.0, 95% CI, 0.0–0.13) in the trabecular metal group (p=0.17). Conclusion. In the two year report on this cohort of patients, we indicated our uncertainty concerning the long term stability of the Trabecular Metal tibial implant due to the high initial migration seen in some cases. In this report we have seen stability of this implant out to five years and migrations in this period below the level of detection of our system in all cases. Given these results it is with increased confidence that we can state that this implant appears to achieve solid fixation despite high initial levels of migration

The trabecular metal Monoblock TKR is comprised of a porous tantalum base plate with the polyethylene liner embedded directly in the porous metal. An alternative design, the trabecular metal Modular TKR, allows polyethylene liner insertion into the locking base plate after base plate implantation, but removes the low modulus of elasticity that was inherent in the Monoblock design. The purpose of this study was to compare the fixation of the Monoblock and Modular trabeucular metal base plates in a randomised controlled trial. Fifty subjects (30 female) were randomly assigned to receive the uncemented trabecular metal Monoblock or uncemented trabecular metal Modular knee replacement. A standard procedure of tantalum marker insertion in the proximal tibial and polyethylene liner was followed with uniplanar radiostereometric analysis (RSA) examinations immediately post-operatively and at 6 week, 3 month, 6 month, and 12 month follow-ups. The study was approved by the Research Ethics Board and all subjects signed an Informed Consent Form. Twenty-one subjects received Monoblock components and 20 received Modular components. An intra-operative decision to use cemented implants occurred in 5 cases and 4 subjects did not proceed to surgery after enrollment. The clinical precision of implant migration measured as maximum total point motion (MTPM) was 0.13 mm (upper limit of 95% confidence interval of double exams). Implant migration at 12 months was 0.88 ± 0.64 mm (mean and standard deviation; range 0.21 – 2.84 mm) for the Monoblock group and 1.60 ± 1.51 mm (mean and standard deviation; range 0.27 – 6.23 mm) for the Modular group. Group differences in 12 month migration approached clinical significance (p = 0.052, Mann Whitney U-test). High early implant migration is associated with an increased risk for late aseptic loosening. Although not statistically significant, the mean migration for the Modular component group was nearly twice that of the Monoblock, which places it at the 1.6 mm threshold for “unacceptable” early migration (Pijls et al 2012). This finding is concerning in light of the recent recall of a similar trabecular metal modular knee replacement and adds validity to the use of RSA in the introduction of new or modified implant designs. Reference: Pijls, B.G., et al., Early migration of tibial components is associated with late revision: a systematic review and meta-analysis of 21,000 knee arthroplasties. Acta Orthop, 2012. 83(6): p. 614–24

Management of severe bone loss in total knee arthroplasty presents a formidable challenge. This situation may arise in neglected primary knee arthroplasty with large deformities and attritional bone loss, in revision situations where osteolysis and loosening have caused large areas of bone loss and in tumor situations. Another area of large bone loss is frequently seen in periprosthetic fractures. Trabecular metal (TM) with its dodecahedron configuration and modulus of elasticity between cortical and cancellous bone offers an excellent bail out option in the management of these very difficult situations. Severe bone loss in the distal femur and proximal tibia lend themselves to receiving the TM cones. The host bone surfaces need to be prepared to receive these cones using a high speed burr. The cones acts as a filler with an interference fit through which the stemmed implant can be introduced and cemented. All areas of bone void is filled with morselised cancellous bone fragments. We present our experience of 64 TM cones (28 femoral, 36 tibial cones) over a 10-year period and our results and outcomes for the same. We have had to revise only one patient for recurrence of the tumor for which the cone was implanted in the first place. We also describe our technique of using two stacked cones for massive distal femoral bone loss and its outcomes. We found excellent osteointegration and new host bone formation around the TM construct. The purported role of possible resistance to infection in situations using the TM cones is also discussed. In summary we believe that the use of the TM cones offers an excellent alternative to massive allografts, custom and/or tumor implants in the management of massive bone loss situations

Purpose:. Acetabular bone loss during revision total hip arthroplasty (THA) poses a challenge for reconstruction as segmental and extensive cavitary defects require structural support to achieve prosthesis stability. Trabecular metal (TM) acetabular augments structurally support hemispherical cups. Positive short-term results have been encouraging, but mid- to long-term results are largely unknown. The purpose of this study was to determine the continued efficacy of TM augments in THA revisions with significant pelvic bone loss. Methods:. Radiographs and medical records of 51 patients who had undergone THA revision with the use of a TM augment were retrospectively reviewed. Acetabular defects were graded according to the Paprosky classification of acetabular deficiencies based on preoperative radiographs and operative findings. Loosening was defined radiographically as a gross change in cup position, change in the abduction angle (>5°), or change in the vertical position of the acetabular component (>8 mm) between initial postoperative and most recent follow-up radiographs (Figure 1). Results:. Eleven patients had incomplete radiographic follow-up and were excluded. The study population included 17 men and 23 women, averaging 68.1 ± 14.1 years of age (range, 37–91), with average radiographic follow-up of 19.0 months (range, 2.4–97.4). Reasons for revision included osteolysis (n = 20, 38.5%), component loosening (n = 18, 15.4%), and periprosthetic fracture (n = 6, 11.5%). All patients underwent revision THA using a TM multi-hole revision acetabular cup and TM acetabular augment(s) to fill bony defects. Morcellized allograft was used in 9 patients. There were 33 Paprosky Type IIIA and seven Paprosky Type IIIB defects. One patient with Paprosky Type IIIB had catastrophic failure of the reconstructive construct three months postoperatively. The remaining 39 acetabular revisions demonstrated signs of bony ingrowth at the latest follow-up. There were no radiolucent lines suggestive of loosening, and no significant differences in abduction angle (p = 0.78), vertical distance between the superolateral edge of the cup and the trans-ischial reference line (p = 0.96), or the vertical distance between the center of the femoral head and trans-ischial reference line (p = 0.75) between the initial postoperative and most recent follow-up radiographs (Figure 2). Discussion and Conclusion:. Achieving fixation and long-term stability in THA revisions with segmental and/or cavitary bone loss is challenging. TM augments provide a modular structural system to achieve bony ingrowth, while avoiding large structural allografts, cages, and custom implants. At latest follow-up, 39 revision hips remained well-fixed with no evidence of loosening. One patient with a significant surgical history of infection, periprosthetic femur fracture, and 2 prior revision surgeries before acetabular reconstruction had an early clinical failure. Trabecular metal augments can be used for reconstruction of acetabular bone loss with good mid-term results. Continued follow-up is warranted for radiographic evaluation of bony integration and implant stability to determine long-term survivorship of these implants

INTRODUCTION. Total knee arthroplasty (TKA) is typically performed using cement to secure the prosthesis to bone. There are complications associated with cementing that include intra-operative hypotension, third-body abrasive wear, and loosening at the cement interfaces. A cementless prosthesis using a novel keeled trabecular metal tibial baseplate was developed to eliminate the need for cementing the tibial component in TKA. METHODS. A retrospective chart review was performed on patients who underwent TKA using cementless tibial and femoral components between August, 2013 and January, 2014. Patients with minimum two-year follow-up including radiographs were included in the analysis. Patient demographics as well as preoperative and postoperative range of motion (ROM) and function were measured using the Knee Society Scoring system (KSS). Post-operative radiographs were assessed for signs of osteolysis, loosening, or subsidence. Paired T-tests were used to identify differences in preoperative and postoperative ROM and KSS. RESULTS. Thirty-three patients underwent 48 TKAs in the study period. Of those, 20 patients (29 knees) completed two-year follow-up. The mean patient age was 69.0 ±8.4 years and mean BMI was 29.9 ±4.3. The average time of follow-up was 24.6 months (range 24–29). Preoperative ROM was on average 4.3–117.3°±6.7 and the preoperative KSS knee scores and functional scores were 43.8 ±8.6 and 49.8 ±12.6, respectively. Postoperatively, there were statistically significant improvements in ROM (0–130.7°±7.3), and postoperative KSS knee (98.4 ±3.2) and functional scores (99.3 ±2.6), at two years, respectively. None of the radiographs demonstrated evidence of osteolysis, loosening, migration, or subsidence. DISCUSSION and CONCLUSION. The two-year results of TKA utilizing a cementless tibial baseplate demonstrate excellent results in terms of knee ROM and function. The radiographic evidence of osteointegration without evidence of loosening, subsidence, or migration of the tibial components is promising. Further follow up is necessary to ensure that these implants will provide a satisfactory long-term alternative to cement fixation

Introduction. Several options exist for the treatment of periprosthetic osteolysis in revision knee surgery. We describe our preliminary short-term experiences using trabecular metal (TM) technology in order to fill bony defects either on the femoral or on the tibial side. Material and Methods. 52 revision knee surgeries in which this TM technology had been used were retrospectively reviewed clinically and radiographically. Indication for revision included 51 cases with aseptic loosening of Total Knee Arthroplasty. In one case of periprostheti infection, a staged revision procedure was performed. Assessment of bone loss included the AORI classification (1989) and was performed pre- and intraoperatively. Clinical evaluation was performed using the HSS score. In 6 cases in addition to usng the TM cones, an impaction grafting technique was performed. Results. Average follow up was 22 months. So far, not loosening of a TM cone neither clinically nor radiographically was observed. In 74% of the cases, either a type FII-TII-FIII or TIII defect was seen. Average number of pre-existing surgeries was 4,6. Pre-operative Range of motion was 0-84 degrees and 0-98 degrees at time of latest follow up. Complications in this series included 2 periprosthetic fractures and 1 periprosthetic infection, later revised to a successful fusion. Upon explantation of the TM cone in this case, stable osteointegration was observed. HSS score increased from 34 to 62 points postoperatively (49-93). Discussion. Treatment of severe periprosthetic osteolysis in our eyes can be managed successfully in the short-term range using TM technology which requires a meticulous surgical technique and proper indication. This material might be successfully combined using homologous bone as an adjunct

Pure tantalum has been proposed in orthopaedic surgery. Its chemical and physical properties have been widely studied in the past. From pure tantalum is obtained a spongy structure (Trabecular Metal Technology: TMT) that shows a full thickness porosity which is 2–3 times higher compared to other surfaces available for bone ingrowth with a three-dimensional porous arrangement in rough trabeculae. Pores (average diameter of 650 mm) are fully interconnected and represent 75–80% of the whole volume. TMT acetabular components have an elliptical shape and have an irregular external surface which both allow an optimal mechanical fit. We retrospectively reviewed 212 cases of monoblock porous tantalum acetabular cup (Hedrocel, Stratec) implanted between 1999 and 2003 in a single centre with a minimum follow-up of 9–10 years; There were 98 men and 114 women, with an average age of 65 years. They all underwent primary or revision total hip arthroplasty or to acetabular component revision alone. In all patients a monoblock porous tantalum acetabular component with polyethylene directly compression molded into cup, with or without peripheral holes for screws, was implanted. In all primary procedures the same femoral stem (Synergy, Smith and Nephew) was implanted. All patients were evaluated with a clinical examination (Harris Hip Score: HHS) and with standard radiographs of the pelvis preoperatively and 1, 3, 6 months and yearly postoperatively. The stability of the acetabular cup was determined by modified Engh's criteria. The HHS score improved from 42 preoperatively to 94 after one year; at 13 years follow-up it was 95. The subjective outcome was widely satisfying, with the majority of patients experimenting good functional recovery and return to daily activities. Osteointegration of the acetabular component was present in all X-rays controls at one year after surgery. All post-operative evidence of residual bone loss (geodes, bone defects in revisions and in displasia) were no more radiographically evident after 1 year postoperatively as the host bone quickly filled these gaps. We did not observe osteolysis nor progressive radiolucent lines at the latest follow-up. None of the cups was revised, except 3 cases, revised for infection. Both clinical and radiographic results are the same or even superior to those of coated implants. Our experience confirms that trabecular metal tantalum cups can avoid the formation of bone-implant interface membrane and consequently can avoid implant loosening. The most important advantages of TMT monoblock cups are: no potential for polyethylene backside wear, prevention of loosening and osteolysis, increased early fixation via friction, improved late biological stability, maximum bone-implant contact. High biocompatibility of porous tantalum and its elastic modulus very close to bone influence positively earlier and wider osteointegration of the implant. Larger series are needed to confirm the positive our preliminary results

Reconstruction of an acetabulum following severe bone loss can be challenging. The aim of this study was to determine the outcome of acetabular reconstruction performed using trabecular metal shell for severe bone loss. Between June 2003 and June 2006 a total of 29 patients with significant acetabular bone stock deficiency underwent revisions using trabacular metal shell. According to Paprosky classification, there were 18 patients with grade IIIA and 11 patients with grade IIIB defects. Nineteen patients required augments to supplement the defects. Functional clinical outcomes were measured by WOMAC and Oxford hip. Detailed radiological assessments were also made. At most recent follow up (average 5.5 years, range 3.5–8.5) the mean Oxford hip score improved from 12 preoperatively to 27.11 postoperatively and WOMAC score from 17.57 preoperatively to 34.14 postoperatively The osseointegration was 83% according to Moore's classification. There were two reoperations; one was for instability, and one for aseptic loosening. One patient has a chronic infection and one had a periprosthetic fracture, both treated conservatively. Despite challenges faced with severe preoperative acetabular defects the early results using this technique in Grade III A and B is encouraging

Recently, the osteoregenerative properties of allograft have been enhanced by addition of autogenous skeletal stem cells to treat orthopaedic conditions characterised by lost bone stock. There are multiple disadvantages to allograft, and trabecular tantalum represents a potential alternative. This metal is widely used, although in applications where there is poor initial stability, or when it is used in conjunction with bone grafting, loading may need to be limited until sound integration has occurred. Strategies to speed up implant incorporation to surrounding bone are therefore required. This may improve patient outcomes, extending the clinical applications of tantalum as a substitute for allograft.

Little information exists regarding optimal tibial stem usage in revision total knee arthroplasty (rTKA) utilising a tibial trabecular metal (TM) cone. The purpose of this study was to compare 1) functional outcomes, 2) radiographic outcomes, and 3) implant survivorship in rTKA utilising TM cones combined with either short stems (SS) or long stems (LS) at minimum two-years clinical follow-up. In this retrospective, multi-centre study, patients undergoing TM cone utilising rTKA between 2008 and 2019 were included. Patients were divided into: SS group (no diaphyseal engagement), and LS group (diaphyseal engagement). All relevant clinical charts and post-operative radiographs were examined. Oxford Knee Score (OKS) and EuroQol-5D (EQ-5D-5L) data were collected at most recent follow-up. In total, 44 patients were included: 18 in the SS group and 26 in the LS group. The mean time of follow-up was 4.0 years. Failure free survival was 94.5% for the SS group and 92.3% for the LS group. All failures were for prosthetic joint infections managed with debridement, antibiotics, and implant retention. At most recent follow-up, 3 patients demonstrated radiographic signs of lucency (1 SS 2 LS, p = 1) and the mean OKS were 37 ± 4 and 36 ± 6 (p = 0.73) in the SS and LS groups, respectively. Tibial SS combined with TM cones performed as well as LS in rTKA at minimum two-years follow-up. A tibial SS in combination with a TM cone is a reliable technique to achieve stable and durable fixation in rTKA