The purposes of this study were to evaluate the accuracy and feasibility of a robotic preparation for acetabular metal augments in patients with developmental dysplasia of the hip (DDH). Mako robotic arm reaming was used in 7 DDH to prepare the bony cavities for both Trident PSL cups and Tritanium acetabular wedge augments in six hips with Crowe 2 or 3 DDH. In CT-based planning, a properly sized cup was placed in the original acetabulum, and the same sized cup was also placed to fit the superolateral acetabular defect. The coordinates of the planned positions of cup and augment were recorded to manage the robotic arm reaming. After registration of the patient's pelvis, robotic reaming was performed first for the augment, then, for the cup by changing the target position of reaming as planned. The accuracy of the cup and augment placement was assessed on postoperative CT. To evaluate the feasibility of the robotic procedure, the OR time and blood loss were compared with those of 13 patients who received the same cup and augment systems with a conventional technique. All procedures were done without fracture or fixation failure. There were no differences in OR time or blood loss between the two procedures. Postoperative CT measurements of the distance between the cup center and the augment sphere center showed less than 2mm difference from the Mako preoperative planning. Although a longer time of follow up evaluation is mandatory, our robotic acetabular augment preparation technique is accurate and feasible

During revision total knee arthroplasty (rTKA), proximal tibial bone loss is frequently encountered and can result in a less-stable bone-implant fixation. A 3D printed titanium alloy (Ti6Al4V) revision augment that conforms to the irregular shape of the proximal tibia was recently developed. The purpose of this study was to evaluate the fixation stability of rTKA with this augment in comparison to conventional cemented rTKA. Eleven pairs of thawed fresh-frozen cadaveric tibias (22 tibias) were potted in custom fixtures. Primary total knee arthroplasty (pTKA) surgery was performed on all tibias. Fixation stability testing was conducted using a three-stage eccentric loading protocol. Static eccentric (70% medial/ 30% lateral) loading of 2100 N was applied to the implants before and after subjecting them to 5×103 loading cycles of 700 N at 2 Hz using a joint motion simulator. Bone-implant micromotion was measured using a high-resolution optical system. The pTKA were removed. The proximal tibial bone defect was measured. One tibia from each pair was randomly allocated to the experimental group, and rTKA was performed with a titanium augment printed using selective laser melting. The contralateral side was assigned to the control group (revision with fully cemented stems). The three-stage eccentric loading protocol was used to test the revision TKAs. Independent t-tests were used to compare the micromotion between the two groups. After revision TKA, the mean micromotion was 23.1μm ± 26.2μm in the control group and 12.9μm ± 22.2μm in the experimental group. There was significantly less micromotion in the experimental group (p= 0.04). Prior to revision surgery, the control and experimental group had no significant difference in primary TKA micromotion (p= 0.19) and tibial bone loss (p= 0.37). This study suggests that early fixation stability of revision TKA with the novel 3D printed titanium augment is significantly better then the conventional fully cemented rTKA. The early press-fit fixation of the augment is likely sufficient for promoting bony ingrowth of the augment in vivo. Further studies are needed to investigate the long-term in-vivo fixation of the novel 3D printed augment

Objectives. In order to address acetabular defects, porous metal revision acetabular components and augments have been developed, which require fixation to each other. The fixation technique that results in the smallest relative movement between the components, as well as its influence on the primary stability with the host bone, have not previously been determined. Methods. A total of 18 composite hemipelvises with a Paprosky IIB defect were implanted using a porous titanium 56 mm multihole acetabular component and 1 cm augment. Each acetabular component and augment was affixed to the bone using two screws, while the method of fixation between the acetabular component and augment varied for the three groups of six hemipelvises: group S, screw fixation only; group SC, screw plus cement fixation; group C, cement fixation only. The implanted hemipelvises were cyclically loaded to three different loading maxima (0.5 kN, 0.9 kN, and 1.8 kN). Results. Screw fixation alone resulted in up to three times more movement (p = 0.006), especially when load was increased to 100% (p < 0.001), than with the other two fixation methods (C and SC). No significant difference was noted when a screw was added to the cement fixation. Increased load resulted in increased relative movement between the interfaces in all fixation methods (p < 0.001). Conclusion. Cement fixation between a porous titanium acetabular component and augment is associated with less relative movement than screw fixation alone for all implant interfaces, particularly with increasing loads. Adding a screw to the cement fixation did not offer any significant advantage. These results also show that the stability of the tested acetabular component/augment interface affects the stability of the construct that is affixed to the bone. Cite this article: N. A. Beckmann, R. G. Bitsch, M. Gondan, M. Schonhoff, S. Jaeger. Comparison of the stability of three fixation techniques between porous metal acetabular components and augments. Bone Joint Res 2018;7:282–288. DOI: 10.1302/2046-3758.74.BJR-2017-0198.R1

Aims. Adenosine, lidocaine, and Mg. 2+. (ALM) therapy exerts differential immuno-inflammatory responses in males and females early after anterior cruciate ligament (ACL) reconstruction (ACLR). Our aim was to investigate sex-specific effects of ALM therapy on joint tissue repair and recovery 28 days after surgery. Methods. Male (n = 21) and female (n = 21) adult Sprague-Dawley rats were randomly divided into ALM or Saline control treatment groups. Three days after ACL rupture, animals underwent ACLR. An ALM or saline intravenous infusion was commenced prior to skin incision, and continued for one hour. An intra-articular bolus of ALM or saline was also administered prior to skin closure. Animals were monitored to 28 days, and joint function, pain, inflammatory markers, histopathology, and tissue repair markers were assessed. Results. Despite comparable knee function, ALM-treated males had reduced systemic inflammation, synovial fluid angiogenic and pro-inflammatory mediators, synovitis, and fat pad fibrotic changes, compared to controls. Within the ACL graft, ALM-treated males had increased expression of tissue repair markers, decreased inflammation, increased collagen organization, and improved graft-bone healing. In contrast to males, females had no evidence of persistent systemic inflammation. Compared to controls, ALM-treated females had improved knee extension, gait biomechanics, and elevated synovial macrophage inflammatory protein-1 alpha (MIP-1α). Within the ACL graft, ALM-treated females had decreased inflammation, increased collagen organization, and improved graft-bone healing. In articular cartilage of ALM-treated animals, matrix metalloproteinase (MMP)-13 expression was blunted in males, while in females repair markers were increased. Conclusion. At 28 days, ALM therapy reduces inflammation, augments tissue repair patterns, and improves joint function in a sex-specific manner. The study supports transition to human safety trials. Cite this article: Bone Joint Res 2024;13(6):279–293

Introduction. In revision TKA, the management of bone loss depends on location, type, and extent of bony deficiency. Treatment strategies involve cement filling, bone grafting and augments. On the market several solutions are currently available, differing for their shape, thickness and material. While the choice of the shape and the thickness is mainly dictated by the bone defect, no explicit guideline is currently available to describe the best choice of material to be selected for a specific clinical situation. However, the use of different materials could induce different response in term of bone stress and thus changes in implant stability that could worsen long-term implant performance. For these reasons, an investigation about the changes in bone stress in the femur and in the tibia when augments, with different materials and thicknesses was performed. Methods. Different configurations have been separately considered including proximal tibial, distal or/and posterior femoral augments with a thickness of 5, 10 and 15 mm. Apart the control, in which no augments were used, but only the TKA is considered, the augment in all the other configurations were considered made by three different materials: bone cement, to simulate cement filling, tantalum trabecular metal and conventional metal (titanium for the tibia and CoCr for the femoral augments). Each configuration was inserted on a lower leg model including a cruciate-retaining total knee arthroplasty and analyzed by means of finite element analysis applying the max force achieved during walking. The bone stress was investigated in the medial and lateral region of interest close to the augment (with a bone thickness of 10 mm) and in an additional bone region of interest of 50 mm thickness. The bone stress have been compared among the different models and also with respect to the control model. Results. In general, the use of an augment induces a change in bone stress, especially in the region close to the bone cuts. The stiffness of the augment must be as close as possible to the one of the bone. Cement has the best results in terms of bone stress, however, it is only suitable for extremely small defects. Tantalum trabecular metal has results very close to cement and it could be consider a good alternative to cement for any size of defect. Metal (both titanium and CoCr) has the least satisfying results inducing the highest change in bone stress with respect the control. Conclusions. Tibial and femoral bone augments are adopted in case of bone defects that could be present during a revision knee replacement. Several solutions are available on the market in different shapes and materials. However, very few studies are reported to provide possible guidelines. The results of this study demonstrate that material stiffness of the augment must be as close as possible to the one of the bone to achieve the best results

Background. Total shoulder arthroplasty is technically demanding in regards to implantation of the glenoid component, especially in the setting of increased glenoid deformity and posterior glenoid wear. Augmented glenoid implants are an important and innovative option; however, there is little evidence accessible to surgeons to guide in the selection of the appropriate size augmented glenoid. Methods. Solid computer models of a commercially available augmented glenoid components (+3, +5, +7) contained within the software allowed for placement of the best fit glenoid component within the 3D reconstruct of each patient's scapula. Peg perforation, amount of bone reamed and amount of medialization were recorded for each augment size. Results. There was strong correlation between the medialization of the joint line and the glenoid retroversion for each augmented component (R. 2. of 0.785 for the +3 augment, an R. 2. of 0.792 for the +5 component, and an R. 2. of 0.701 for the +7 component). The range of retroversion that restored anatomic joint line using the +3 augmented glenoid was −3° to −17°, −5° to −24° using the +5 augmented glenoid, and −9° to −31° for a +7 augmented glenoid. Conclusions. Our results provide a general guideline for clinicians to select an appropriate sized augmented glenoid implant based on range of glenoid retroversion that can be corrected to restore the native joint line and minimize peg perforation. There was a strong correlation between glenoid retroversion and medialization for all augment sizes supporting the recommendation for glenoid retroversion as the primary guide in selecting the amount of augmentation

The amount of bone loss due to implant failure, loosening, or osteolysis can vary greatly and can have a major impact on reconstructive options during revision total knee arthroplasty (TKA). Massive bone loss can threaten ligamentous attachments in the vicinity of the knee and may require use of components with additional constraint to compensate for associated ligamentous instability. Classification of bone defects can be helpful in predicting the complexity of the reconstruction required and in facilitating pre-operative planning and implant selection. One very helpful classification of bone loss associated with TKA is the Anderson Orthopaedic Research Institute (AORI) Bone Defect Classification System as it provides the means to compare the location and extent of femoral and tibial bone loss encountered during revision surgery. In general, the higher grade defects (Type IIb or III) on both the femoral and tibial sides are more likely to require stemmed components, and may require the use of either structural graft or large augments to restore support for currently available modular revision components. Custom prostheses were previously utilised for massive defects of this sort, but more recently have been supplanted by revision TKA component systems with or without special metal augments or structural allograft. Options for bone defect management are: 1) Fill with cement; 2) Fill with cement supplemented by screws or K-wires; 3) Morselised bone grafting (for smaller, especially contained cavitary defects); 4) Small segment structural bone graft; 5) Impaction grafting; 6) Large prosthetic augments (cones); 7) Massive structural allograft-prosthetic composites (APC); 8) Custom implants. Maximizing support on intact host bone is a fundamental principle to successful reconstruction and frequently requires extending fixation to the adjacent diaphysis. Pre-operative planning is facilitated by good quality radiographs, supplemented on occasion by additional imaging such as CT. Fluoroscopically controlled x-ray views may assist in diagnosing the loose implant by better revealing the interface between the implant and bone and can facilitate accurate delineation of the extent of bone deficiency present. Part of the pre-operative plan is to ensure adequate range and variety of implant choices and bone graft resources for the planned reconstruction allowing for the potential for unexpected intra-operative findings such as occult fracture through deficient periprosthetic bone. Reconstruction of bone deficiency following removal of the failed implant is largely dictated by the location and extent of bone loss and the quality of bone that remains. While massive bone loss may compromise ligamentous attachment to bone, in the majority of reconstructions the degree of implant constraint needed for proper balancing and restoration of stability is independent of the bone defect. Thus some knees with minimal bone deficiency may require increased constraint due to the status of the soft tissues while others involving very large bone defects especially of the cavitary sort may be well managed with minimal constraint

The amount of bone loss due to implant failure, loosening, or osteolysis can vary greatly and can have a major impact on reconstructive options during revision total knee arthroplasty (TKA). Massive bone loss can threaten ligamentous attachments in the vicinity of the knee and may require use of components with additional constraint to compensate for associated ligamentous instability. Classification of bone defects can be helpful in predicting the complexity of the reconstruction required and in facilitating preoperative planning and implant selection. One very helpful classification of bone loss associated with TKA is the Anderson Orthopaedic Research Institute (AORI) Bone Defect Classification System as it provides the means to compare the location and extent of femoral and tibial bone loss encountered during revision surgery. In general, the higher grade defects (Type IIb or III) on both the femoral and tibial sides are more likely to require stemmed components, and may require the use of either structural graft or large augments to restore support for currently available modular revision components. Custom prostheses were previously utilised for massive defects of this sort, but more recently have been supplanted by revision TKA component systems with or without special metal augments or structural allograft. Options for bone defect management are: 1) Fill with cement; 2) Fill with cement supplemented by screws or K-wires; 3) Morselised bone grafting (for smaller, especially contained cavitary defects); 4) Small segment structural bone graft; 5) Impaction grafting; 6) Large prosthetic augments (cones); 7) Massive structural allograft-prosthetic composites (APC); 8) Custom implants. Maximising support on intact host bone is a fundamental principle to successful reconstruction and frequently requires extending fixation to the adjacent diaphysis. Preoperative planning is facilitated by good quality radiographs, supplemented on occasion by additional imaging such as CT. Fluoroscopically controlled x-ray views may assist in diagnosing the loose implant by better revealing the interface between the implant and bone and can facilitate accurate delineation of the extent of bone deficiency present. Part of the preoperative plan is to ensure adequate range and variety of implant choices and bone graft resources for the planned reconstruction allowing for the potential for unexpected intraoperative findings such as occult fracture through deficient periprosthetic bone. Reconstruction of bone deficiency following removal of the failed implant is largely dictated by the location and extent of bone loss and the quality of bone that remains. While massive bone loss may compromise ligamentous attachment to bone, in the majority of reconstructions the degree of implant constraint needed for proper balancing and restoration of stability is independent of the bone defect. Thus some knees with minimal bone deficiency may require increased constraint due to the status of the soft tissues while others involving very large bone defects especially of the cavitary sort may be well managed with minimal constraint

The amount of bone loss due to implant failure, loosening, or osteolysis can vary greatly and can have a major impact on reconstructive options during revision total knee arthroplasty. Massive bone loss can threaten ligamentous attachments in the vicinity of the knee and may require use of components with additional constraint to compensate for associated ligamentous instability. Classification of bone defects can be helpful in predicting the complexity of the reconstruction required and in facilitating preoperative planning and implant selection. One very helpful classification of bone loss associated with TKA is the Anderson Orthopaedic Research Institute (AORI) Bone Defect Classification System. This system provides the means to compare the location and extent of femoral and tibial bone loss encountered during revision surgery. In general, the higher grade defects (Type IIb or III) on both the femoral and tibial sides are more likely to require stemmed components, and may require the use of either structural graft or large augments to restore support for currently available modular revision components. Custom prostheses were previously utilised for massive defects of this sort, but more recently have been supplanted by revision TKA component systems with or without special metal augments or structural allograft. Options for bone defect management are as follows: 1) fill with cement, 2) fill with cement supplemented by screws or K-wires, 3) Morsellised bone grafting (for smaller, especially contained cavitary defects), 4) Small segment structural bone graft, 5) Impaction grafting, 6) Large prosthetic augments (cones), 7) Massive structural allograft-prosthetic composites (APC), 8) Custom implants. It is very helpful for revision surgeons to have a variety of reconstructive options available, even despite a well thought-out preoperative plan. Preoperative planning is important but the plan that results may require alteration during the course of the surgery to accommodate bone defects which are either less or more severe than thought pre-operatively, and to adjust to variable quality and extent of host bone remaining, as this provides the mechanical platform for the reconstruction. Maximising support on intact host bone is a fundamental principle to successful reconstruction and frequently requires extending fixation to the adjacent diaphysis. Bone defect management during revision total knee arthroplasty can provide a wide range of challenges from relatively trivial problems with small defects manageable with cement or small amounts of cancellous graft to massive deficiencies that may defy reconstruction except with allograft prosthetic components or large segmental replacing tumor-type implants. The more common Type II deficiencies increasingly seen in the context of particulate driven osteolysis demand a wide range of implant and bone graft options so that an individualised reconstruction can be accomplished for that particular patient based on bone defect size, location, quality of bone remaining, ligamentous status, and anticipated patient demands

The major causes of revision total knee are associated with some degree of bone loss. The missing bone must be accounted for to insure success of the revision procedure, to achieve flexion extension balance, restore the joint line to within a centimeter of its previous level, and to assure a proper sizing especially the anteroposterior diameter of the femoral component. In recent years, clinical practice has evolved over time with a general move away from a structural graft with an increase in utilisation of metal augments. Alternatives include cement with or without screw fixation, rarely, with the most common option being the use of metal wedges. With the recent availability of highly porous augments, the role of metal augmentation has increased. Bone graft is now predominantly used in particulate form for contained defects with more limited use of structural graft. The role of the allograft-prosthetic composite has become more limited. For the elderly with osteopenia and massive bone loss, complete metal substitution with an oncology prosthesis has become more common. The degree of bone loss is a major determinant of the management strategy. For contained defects less than 5 mm, cement alone, with or without screw supplementation, may be adequate. For greater than 5 mm, morselised graft is frequently used. For uncontained defects of up to 15 mm or more, metal augmentation is the first choice. Bone graft techniques can be utilised in this setting, however, these are more time consuming and technically demanding with little demonstrated advantage. For larger, uncontained defects, newer generation highly porous augments and step wedges are useful. Large contained defects can be dealt with utilising impaction grafting, similar to the hip impaction grafting technique. Massive distal defects are expeditiously managed with oncology defects in the case of periprosthetic fracture and/or massive osteolysis particularly when combined with osteopenia in an elderly, low demand patient. Surgeons must be familiar with an array of techniques in order to effectively deal with the wide spectrum of bone defects encountered during revision total knee arthroplasty

Introduction: Screws placed in the fibula do not have a satisfactory purchase during internal fixation of an osteoporotic ankle fracture. Tibia-pro-fibula screws that extend from the fibula into the distal tibial metaphysis provide additional purchase. The purpose of this study is to investigate if purchase of these screws can be enhanced further by injecting calcium sulfate and calcium phosphate composite graft in the drill holes prior to insertion of the screws. Methods: Bone density was quantified using DEXA scan in paired cadaver legs. One leg from each pair was randomly selected for injection of composite graft into screw holes before insertion of the screws. Two screws were inserted through the fibula into the distal tibial metaphysis in each leg, at the level of the syndesmosis under fluoroscopy in a standardized fashion using a jig. The screws were pulled out using a materials testing machine. Stiffness, force, displacement, and energy required were recorded. Results: After testing 4 pairs of cadaver legs, a statistically significant difference was noted in displacement, failure load, and failure energy between augmented and non-augmented screws, with the augmented screws being considerably stronger. Of the two screws the distal, when compared to the proximal one, required more displacement, higher force and energy to fail whether augmented with composite graft or not. Conclusion: Screws augmented with composite graft provide significantly greater purchase in an osteoporotic distal tibial metaphysis than non-augmented screws. Clinical relevance: Use of composite graft to augment purchase of the screws inserted in the distal tibial metaphysis may enhance the stability of the internal fixation of an osteoporotic ankle fracture. This will enable early weight-bearing mobilization and return to function which is important in elderly patients

Introduction. This study investigated the binding agent Calcium/Sodium Alginate fibre gel and the addition of autogenic bone marrow aspirate (BMA) on bone growth into a porous HA scaffold implanted in an ovine femoral condyle critical-sized defect. Our hypothesis was that Alginate fibre gel would have no negative effect on bone formation and osteoconduction within the scaffold and that BMA would augment the incorporation of the graft with the surrounding bone at 6 and 12 weeks post implantation. Methods. 24, 8mm x 15mm defects were filled with either porous HA granules, porous HA granules + Alginate fibre gel (HA putty) or porous HA granules + Alginate fibre gel + BMA (HA putty +BMA) and remained in vivo for 6 and 12 weeks (n=4). 1ml of bone marrow aspirate per cm3 of graft was used. Image analysis quantified bone apposition rates, bone ingrowth, bone-implant contact and quantity of graft. Mann Whitney U tests were used for statistical analysis where p<0.05 was considered significant. Results. Highest bone formation were measured in the 12 week HA putty+BMA group (1.57±0.24(micromillimetres/day). HA granules at 12 weeks encouraged the greatest increase in bone formation (33.56±3.53%). Smaller amounts of bone was measured in the 6 week HA putty+BMA group (8.57±2.86%). Bone formation in the HA group at 12 weeks was significantly higher when compared with the HA putty (p= 0.043) and the HA putty+BMA group (p= 0.043). At both the 6 and 12 week time point, highest bone-implant contact was seen in the HA granules group (59.34±10.89% and 72.65±3.38% respectively) when compared with both the HA putty (p=0.018) and HA putty+BMA (p=0.047). Results showed no significant difference in the amount of implant remaining when each group was compared. Conclusions. Results from this study showed that the inclusion of BMA did not augment bone growth to the scaffold or increase its osteoconductive capacity when combined with Calcium/Sodium Alginate fibre gel. Further research is necessary to optimise Calcium/Sodium Alginate fibre gel when used to bind HA granules and to investigate the effect of BMA with this type of HA alone

Massive bone loss on both the femur and tibia during revision total knee arthroplasty (TKA) remains a challenging problem. Multiple solutions have been proposed for small osseous defects, including morselised cancellous bone grafting, small-fragment structural allograft, thicker polyethylene inserts, and the use of modular augments attached to revision prosthetic designs. Large osseous defects can be treated with structural allografts, impaction bone-grafting with or without mesh augmentation, custom prosthetic components, and specialised hinged knee components. The metaphyseal area of the distal femur and proximal tibia is a particularly attractive option during revision TKA given that it is usually undamaged and well-vascularised. While multiple reconstructive options have been recommended, porous tantalum metaphyseal cones have the advantage of improved biologic fixation because of their high porosity (75–80%), interconnected pore space, and low modulus of elasticity (3 MPa) similar to that of cancellous bone. Such features allow tantalum cones to fill bone defects while tolerating physiological loads. Indications for porous tantalum metaphyseal cones include patients with Anderson Orthopaedic Research Institute Type 2B or greater defects. The surgical technique is simpler than structural allograft reconstructions with decreased preparation time, resulting in a possible decrease in infection rates. The modularity of porous tantalum metaphyseal cones also allows the surgeon to choose a size and position that best fits the individual defect encountered. Moreover, tantalum cones can be used with several revision systems. Short-term clinical follow up indicates that porous tantalum metaphyseal cones effectively provide structural support with the potential for long-term biologic fixation and durable reconstructions

Purpose:. To examine the performance of a novel blood plasma-based bone putty for augmenting the treatment of open tibia fractures. The putty was manufactured from pooled blood plasma and contains a concentration of both plasma and platelet-derived regenerative factors. Based on clinical reports of the use of autologous platelet-rich plasma to treat injuries, we hypothesized that the putty would accelerate healing of fractures and surrounding soft tissues. Methods:. Two-arm, randomized controlled study including 20 treatment patients and 10 controls. Follow-up examinations occurred at 14, 30, 60, 90, 180, and 365 days. The product was provided in a syringe containing 3 cc of putty in a double-pouched, sterile box. The putty was placed at the fracture site during open fracture reduction and mechanical stabilization. Results:. Both treatment and control groups were well balanced with a mean age of 35. Seventy percent were Gustillo IIIA and IIIB injuries, 67% were active smokers, and 70% received external fixation. No adverse events related to the use of the putty were noted. The use of the putty significantly reduced infections at 90 days (p = 0.002), accelerated bone bridging at 90 and 180 days, and provided more rapid wound closure at 30 days. In the subset of patients with IIIA/IIIB injuries, the putty group demonstrated more significantly reduced infections (p = 0.0007), with accelerated bone healing and wound closure approaching statistical significance. There were statistically fewer adverse events with the putty (42.1%) compared to controls (80.0%). Conclusions:. The potential for using a concentration of natural plasma and platelet-derived regenerative factors to augment the healing of traumatic injuries makes this first-in-man study relevant and exciting. The putty performed as expected, promoting more rapid healing of both fractures and wounds. The dramatic reduction in infections was unanticipated and is likely related to antimicrobial peptides in plasma and platelets

Introduction: Acetabular bone defects are critical and frustrating issue; indeed is possible to obtain good reconstruction with conventional Methods: (i.e. bulk graft, cage and cement) but good results are limited to short and mid term. Aim of this paper is to present reconstructive method based on filling the defect with an augment made of tantalum (augmentation technique). Methods: We analized 42 cases from February 2005 to March 2009 with an average age of 63 years old with acetabular defect, scored 3A or more (4 patients had pelvic disjunction) according Paprosky classification. The average age was very low, with 12 cases under 60 years (28,57%) and 21 under 70 (50%). 18 patients were re-revision (at time of surgery were at third or fourth surgical procedure) representing 54,2% of cases. Complete clinical, radiographic evaluation and survivorship analysis for the entire study cohort was performed from an average follow up of 26 months (min 6–max 55 months). Results and Discussion: Preliminar results are encouraging: in only two case we had poor results with step pain and prescribed partial load and walking with two crutches, slight radiographic sign of migration where present at the last follow-up. These patients were previously submitted to many surgical procedures with significant bone loss, soft tissue damages and both with history of previous infection, classified as pelvic disjunction. One of these reported a ischiatic palsy. In the remaining cases we obtained good functional recover, no failures at two years average of follow-up. 40 patients didn’t show hip or groin pain during stance position or walking, no bone resorption or implant mobilization were seen at radiographic follow-up. The HHS increases from 23,04 pre op to 85,15 post op. In no case were found clinical, radiographic, or biochemical signs of infection. According with literature the rationale of augmentation technique with trabecular metal should give long lasting favourable results for its excellent bone ingrowth and mechanical properties. Our results almost match the results of other authors. These brilliant results, partially due to osteoconductive proprieties of tantalum (despite we require time to confirmate), are certainly obtained thank to the optimal centre of rotation reconstruction, always close the physiological one

Introduction. Surgeons are often confronted with large amounts of bone loss during the revision of total hip prostheses. Regularly, porous metals are applied to reconstruct the missing bone. Rapid and extensive bone infiltration into the implant's pores is essential to obtain strong and durable biological fixation. Today, specialised layered manufacturing techniques provide the flexibility to produce custom-made metallic implants with a personalized external shape and a well-controlled internal network of interconnected pores. In this study, bone ingrowth in porous titanium structures that were manufactured by selective laser melting (SLM) was evaluated in an in vivo goat model. Methods. Cylindrical Ti6Al4V constructs (Ø8mm × 14mm, porosity 75%) with or without hydroxyapatite coating were implanted in six Saanen goats. Three holes were drilled in the subchondral bone of each tibia and femur. Constructs were inserted into the holes in a press-fit manner. Resonance frequency analysis was used to measure construct stability. At 3, 6 and 9 weeks after surgery, fluorochrome labels were injected. After 6 and 12 weeks, samples were explanted. Some samples were scanned with micro-CT and subsequently sectioned for histological analysis. The others were used for pull-out tests. Results. Resonance frequency analysis indicated a noticeable increase in implant stability. Evaluation of micro-CT and histological data showed bone ingrowth for all goats at 6 and 12 weeks. Most bone ingrowth occurred during the first 6 weeks, which was followed by a slight increase between week 6 and 12. Fluorochrome labeling confirmed these results. Pull-out tests showed an increased fixation at the bone-implant interface. Conclusion. Porous titanium structures manufactured by SLM have good osseointegration characteristics. As custom-made bone augments, they provide a promising approach to the reconstruction of severe bone defects

Cement-induced thermal osteonecrosis is well documented, as is the potential for nerve injury from thermal energy. Cement is often used to augment fixation following excision of humeral metastases. Porcine femurs were used as a model. We sought to find out the maximum temperatures that would be reached in various parts of the bone during the cement setting process, to explore what negative effects this might have on neighbouring bone and nerve. A 12mm by 12mm window was cut from 12 porcine femoral shafts, and Palacos R+D cement injected into the defect. As cement set, bone surface temperature was measured using infra-red thermal imaging and thermocouples used to measure temperatures at the bone-cement interface, 5mm from the cement bolus, 10mm from cement bolus and an area running around the shaft replicating radial nerve. Bone surface temperature rose to a maximum of 34.0 C (on average), and 32.9 C in the ‘radial nerve’ thermocouple. Notably, in two bones there were fractures during specimen preparation, and maximum temperatures in these two areas exceeded 41 degrees C. Average maximum temperatures were 58.1 C, 36.5 C and 30.1 C at the bone cement interface, 5mm and 10mm from the cement bolus respectively

Purpose

The aim of this study was to report the outcomes of a series of patients with clavicle fracture non-union who had undergone open reduction and internal fixation using a contoured locking plate without the use of distant bone graft.

Acetabular bone structure is not the same in all patients and can be defined by the radiolucent triangle superior to the acetabulum. We ask if the acetabular anatomy determines the initial cup fixation and screws use.

We have assessed 205 hips in which a Cerafit cementless cup was implanted. According to Dorr et al., acetabulae were classified as type A, in which the radiolucent triangle had an isosceles shape (86 hips), type B, in which the triangle extended into the teardrop (90 hips), and type C which had a right-angle triangle (29 hips). The use of screws was decided at the time of surgery and according to cup stability, not acetabular anatomy.

Avascular necrosis and inflammatory arthritis were the most frequent diagnoses in type A hips, osteoarthritis in type B, and dysplasia in type C. Women were more frequent in types A and C (p< 0.001). The use of screws was more frequent in women (p< 0.001) and in type A (34.9%) and type C hips (62.1%) than in type B hips (20.0%) (p< 0.001). The multivariate logistic regression model showed the acetabular type (p=0.11) and gender (p=0.003) as independent factors. Acetabular types A (OR=1.98, 95% CI: 0.922–4.208, p=0.075) and C (OR=5.09, 95% CI: 1.74–14.9, p=0.003) increase the risk for screw use. Men have a lower risk for screw use (OR=0.329, 95% CI: 0.16–0.68, p=0.003).

Acetabular anatomy and gender determine the use of screws in cementless cups. Continued follow-up is necessary to determine if screws results in less loosening and osteolysis.

Revision TKA patients who have severe patellar bone loss or undergo patellectomy often have inferior clinical results. Current treatments are limited and often unsatisfactory. This study reports the surgical technique and clinical follow-up (4-year minimum) for 10 patients who underwent revision or salvage TKA and received a porous tantalum implant for replacement of their patella.

The prosthesis is comprised of two parts, a poroustantalum base and titanium suture ring for initial fixation, and a polyethylene surface that is cemented to the base. The surgical technique evolved over the course of the first three cases, during which the suture technique and size (non-absorbable number 2) and bone preparation were defined.

The results of this study indicate that this porous tantalum patella is an effective prosthetic option that is capable of improving function and reducing pain for patients with severe patellar boneloss and complicating factors.