Concepts in glenoid tracking and treatment strategies of glenoid bone loss are well established. Initial observations in our practice in Singapore showed few patients with major bone loss requiring glenoid reconstructions. This led us to investigate the incidence of and the extent of bone loss in our patients with shoulder instability. Our study revealed bony Bankart lesions were seen in 46% of our patients but glenoid bone loss measured only 6–10% of the glenoid surface. In the same study we found that arthroscopic labral repair with capsular plication and Mason-Ellen suturing (Hybrid technique) was sufficient to stabilise patients with bipolar bone defects and minor glenoid bone loss. This led us to develop the concept of minor bone loss and a new algorithm. Our algorithm and strategies to deal with major bone loss will also be discussed, and techniques & outcomes of Arthroscopic Bony Bankart repair, Arthroscopic Glenoid Reconstruction and Arthroscopic Remplissage procedures will be shown

Rates of prosthetic joint infection in megaprostheses are high. The application of silver ion coating to implants serves as a deterrent to infection and biofilm formation. A retrospective review was performed of all silver-coated MUTARS endoprosthetic reconstructions (SC-EPR) by a single Orthopaedic Oncology Surgeon. We examined the rate of component revision due to infection and the rate of infection successfully treated with antibiotic therapy. We reviewed overall revision rates, sub-categorised into the Henderson groupings for endoprosthesis modes of failure (Type 1 soft tissue failure, Type 2 aseptic loosening, Type 3 Structural failure, Type 4 Infection, Type 5 tumour progression). 283 silver-coated MUTARS endoprosthetic reconstructions were performed for 229 patients from October 2012 to July 2022. The average age at time of surgery was 58.9 years and 53% of our cohort were males. 154 (71.3%) patients underwent SC-EPR for oncological reconstruction and 32 (14.8%) for reconstruction for bone loss following prosthetic joint infection(s). Proximal femur SC-EPR (82) and distal femur (90) were the most common procedures. This cohort had an overall revision rate of 21.2% (60/283 cases). Component revisions were most commonly due to Type 4 infection (19 cases), Type 2 aseptic loosening/culture negative disease (15 cases), and Type 1 dislocation/soft tissue (12 cases). Component revision rate for infection was 6.7% (19 cases). 15 underwent exchange of implants and 4 underwent transfemoral amputation due to recalcitrant infection and failure of soft tissue coverage. This equates to a limb salvage rate of 98.3%. The most common causative organisms remain staphylococcus species (47%) and polymicrobial infections (40%). We expand on the existing literature advocating for the use of silver-coated endoprosthetic reconstructions. We provide insights from the vast experience of a single surgeon when addressing patients with oncological and bone loss-related complex reconstruction problems

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

In the setting of traumatic elbow injuries involving coronoid fractures, the relative size of the coronoid fragment has been shown to relate to the stability of the joint. Currently, the challenge lies in accurately classifying the amount of bone loss in coronoid fractures. In comminuted fractures, bone loss is difficult to measure with plain radiographs or computed tomography. The purpose of this study is to describe a novel radiographic measure, the Coronoid Opening Angle (COA), on lateral elbow radiographs. We demonstrate the relationship of the COA to coronoid height and describe how this measure can be used to estimate bone loss and potentially predict elbow instability following coronoid fracture. Radiographs were drawn from a regional database in a consecutive fashion. Candidate radiographs were excluded on the basis of radiographic evidence of degenerative changes, previous surgery or injury, bony deformity, and inadequate lateral view of the elbow. The COA was measured as the angle between the long axis of the ulna at the level of the trochlear notch, and the tip of coronoid, from a common origin at the posterior cortex of the olecranon. Images were reviewed by a fellowship trained upper extremity surgeon, an upper extremity fellow, and a junior resident. Normal COA, coronoid height, and calculated COA at varying amounts of bone loss were calculated by three reviewers. A sensitivity analysis was performed to determine how the COA can most effectively predict bone loss at varying coronoid heights. Intraclass correlation coefficient (ICC) was calculated for 39 subjects. Seventy-two subjects were included for analysis (M=40, F=32). The normal coronoid opening angle is 33.19 degrees [32.2 – 34.2]. Coronoid height is 18.8 mm [18.1 – 19.6]. Extrapolating this baseline data, the COA at 20%, 33%, and 50% of coronoid bone loss was calculated to be 27.5, 23.5, and 18 degrees, respectively. ICC was found to be 0.90 or higher. Cutoff values were determined to maximize the sensitivity of the COA. A cutoff value of 21 degrees has a 92% sensitivity in detecting a minimum of 50% bone loss. The COA with similar sensitivity in predicting 20% and 33% bone loss are 32 and 27 degrees. The coronoid opening angle is a novel technique that can be used on a lateral elbow radiograph to predict the minimum coronoid bone loss. This can be used to guide clinical decision making and potentially predict instability. Future research will aim to validate this tool in the clinical setting in predicting instability

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) Porous metal cones or sleeves 7) Massive structural allograft-prosthetic composites; 8) Custom implants. Of these, use of uncemented highly porous metal metaphyseal cones in combination with an initial cemented or partially cemented implant has been shown to provide versatile and highly durable results for a range of bone defects including those previously requiring structural bone graft. The hybrid fixation combination of both cement and cementless fixation of an individual tibial or femoral component has emerged as a frequent and often preferred technique. Initial secure and motionless interfaces are provided by the cemented portions of the construct, while subsequent bone ingrowth to the cementless porous metal portions is the key to long term stable fixation. As bone grows into the porous portions there is off loading and protection of the cemented interfaces from mechanical stresses. While maximizing support on intact host bone has been a longstanding fundamental principle of revision arthroplasty, this is facilitated by the use of metaphyseal cones or sleeves in combination with initial fixation into 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. While massive bone loss may compromise ligamentous attachment to bone, in the majority of reconstructions, the degree of revision 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 management of bone loss in revision total knee replacement (TKA) remains a challenge. To accomplish the goals of revision TKA, the surgeon needs to choose the appropriate implant design to “fix the problem,” achieve proper component placement and alignment, and obtain robust short- and long-term fixation. Proper identification and classification of the extent of bone loss and deformity will aid in preoperative planning. Extensive bone loss may be due to progressive osteolysis (a mechanism of failure), or as a result of intraoperative component removal. The Anderson Orthopaedic Research Institute (AORI) is a useful classification system that individually describes femoral and tibial defects by the appearance, severity, and location of bone defects. This system provides a guideline to treatment and enables preoperative planning on radiographs. In Type 1 defects, femoral and tibial defects are characterised by minor contained deficiencies at the bone-implant interface. Metaphyseal bone is intact and the integrity of the joint line is not compromised. In this scenario, the best reconstruction option is to increase the thickness of bone resection and to fill the defect with cancellous bone graft or cement. Type 2 defects are characterised by deficient metaphyseal bone involving one or more femoral condyle(s) or tibial plateau(s). The peripheral rim of cortical bone may be intact or partially compromised, and the joint line is abnormal. Reconstruction options for a Type 2A defect include impaction bone grafting, cement, or more commonly, prosthetic augmentation (e.g. sleeves, augments or wedges). In Type 2B defects, metaphyseal bone of both femoral condyles or both tibial plateaus is deficient. The peripheral rim of cortical bone may be intact or partially compromised, and the joint line is abnormal. Options for a Type 2B defect include impaction grafting, bulk structural allograft, prosthetic augmentation, metaphyseal sleeves (in some cases), or metaphyseal cones. Finally, in the presence of a Type 3 deficiency, both metaphyseal and cortical bone is deficient and there is partial or complete disruption of the collateral ligament attachments. In this case, the most commonly used reconstruction options include hinged implants or megaprostheses with or without bulk structural allograft, prosthetic augmentation, and/or metaphyseal/diaphyseal sleeves or cones. Today, we are fortunate to have a wide variety of options available to aid in reconstruction of a revision TKA with massive bone loss. Historically, use of cement, bone grafting, or use of a tumor-type or hinged implant were considered the main options for reconstruction. The development and adoption of highly porous sleeves and cones has given the surgeon a new and potentially more durable option for reconstruction of previously difficult to treat defects. Using radiographs and computed tomography, surgeons are able to preoperatively classify bone loss and anticipate a reconstruction plan based upon the classification; however, it is always important to have several back-up options on hand during revision surgery in the event bone loss is worse than expected

In osteoporosis treatment, current interventions, including pharmaceutical treatments and exercise protocols, suffer from challenges of guaranteed efficacy for patients and poor patient compliance. Moreover, bone loss continues to be a complicating factor for conditions such as spinal cord injury, prescribed bed-rest, and space flight. A low-cost treatment modality could improve patient compliance. Electrical stimulation has been shown to improve bone mass in animal models of disuse, but there have been no studies of the effects of electrical stimulation on bone in the context of bone loss under hormone deficiency such as in post-menopausal osteoporosis. The purpose of this study was to explore the effects of electrical stimulation on changes in bone mass in the ovariectomized rat model of post-menopausal osteoporosis. All animal protocols were approved by the institutional Animal Research Ethics Board. We developed a custom electrical stimulation device capable of delivering a constant current, 15 Hz sinusoidal signal. We used 30 female Sprague Dawley rats (12–13 weeks old). Half (n=15) were ovariectomized (OVX), and half (n=15) underwent sham OVX surgery (SHAM). Three of each OVX and SHAM animals were sacrificed at baseline. The remaining 24 rats were separated into four equal groups (n=6 per group): OVX electrical stimulation (OVX-stim), OVX no stimulation (OVX-no stim), SHAM electrical stimulation (SHAM-stim), and SHAM no stimulation (SHAM-no stim). While anaesthetized, stimulation groups received transdermal electrical stimulation to the right knee through bilateral skin-mounted electrodes (10 × 10 mm) with electrode gel. The left knee served as a non-stimulated contralateral control. The no-stimulation groups had electrodes placed on the right knee, but not connected. Rats underwent the stim/no-stim procedure for one hour per day for six weeks. Rats were sacrificed (CO2) after six weeks. Femurs and tibias were scanned by microCT focussed on the proximal tibia and distal femur. MicroCT data were analyzed for trabecular bone measures of bone volume fraction (BV/TV), thickness (Tb.Th), and anisotropy, and cortical bone cross-sectional area and second moment of area. Femurs and tibias from OVX rats had significantly less trabecular bone than SHAM (femur BV/TV = −74.1%, tibia BV/TV = −77.6%). In the distal femur of OVX-stim rats, BV/TV was significantly greater in the stimulated right (11.4%, p < 0 .05) than the non-stimulated contralateral (left). BV/TV in the OVX-stim right femur also tended to be greater than that in the OVX-no-stim right femur, but the difference was not significant (17.7%, p=0.22). There were no differences between stim and no-stim groups for tibial trabecular measures, or cortical bone measures in either the femur or the tibia. This study presents novel findings that electrical stimulation can partially mitigate bone loss in the OVX rat femur, a model of human post-menopausal bone loss. Further work is needed to explore why there was a differential response of the tibial and femoral bone, and to better understand how bone cells respond to electrical stimulation. The long-term goal of this work is to determine if electrical stimulation could be used as a complementary modality for preventing post-menopausal bone loss

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. Highly porous metal augments designed to reestablish metaphyseal support and function in the manner of a prosthetic structural graft have been introduced or are under development by several manufacturers. Published reports of short term experiences have been encouraging for both the tibial side and for femoral augmentation. It remains to be seen whether these implants will provide the desired longer term durability

With increasing burden of revision hip arthroplasty, one of the major challenge is the management of bone loss associated with previous multiple surgeries. Proximal femoral replacement (PFR) has already been popularised for tumour surgeries. The inherent advantages of PFR over allograft –prosthesis system, which is the other option for addressing severe bone loss include, early weight bearing and avoidance of non-union and disease transmission. Our study explores PFR as a possible solution for the management of complex hip revisions. Thirty consecutive hips (29 patients) that underwent PFR between January 2009 and December 2015 were reviewed retrospectively for their clinical and radiological outcomes. The Stanmore METS system was used in all these patients. Mean age at the index surgery (PFR) was 72.69 years (range 50–89) with number of previous hip arthroplasties ranging from 1–5. At mean follow up of 32.27 months, there were no peri-prosthetic fractures and no mechanical failure of the implants. Clearance of infection was achieved in 80% of cases. There was 1 early failure due to intra-operative perforation of femoral canal needing further revision and two were revised for deep infection. Instability was noted in 26.7% (8) of the hips, of which, 87.5% (7) needed further revision with constrained sockets. Out of these 8 hips with instability, 5 had pre-operative infection. Deep infection was noted in 20% (6) of the hips, of which, 5 were primarily revised with PFR for septic loosening. However, further surgeries were essential for only 3 patients. One patient has symptomatic aseptic acetabular loosening and 1 had asymptomatic progressive femoral side loosening (lost to follow up). Severe proximal femoral bone loss in complex revision arthroplasties has necessitated the use of PFR prosthesis. Our study supports the fact that PFR is probably a mechanically viable option for complex revisions. Significant numbers of dislocations and infections could be attributed to the poor soft tissue envelope around the hip. Further surgical techniques in the form use of dual mobility cups and silver coated PFR implants need to be explored

The inflammatory cascade associated with prosthetic implant wear debris, in addition to diseases such as rheumatoid arthritis and periodontitis, it is shown to drastically influence bone turnover in the local environment. Ultimately, this leads to enhanced osteoclastic resorption and the suppression of bone formation by osteoblasts causing implant failure, joint failure, and tooth loosening in the respective conditions if untreated. Regulation of this pathogenic bone metabolism can enhance bone integrity and the treatment bone loss. The current study used novel compounds that target a group of enzymes involved with the epigenetic regulation of gene expression and protein function, histone deacetylases (HDAC), to reduce the catabolism and improve the anabolism of bone material in vitro. Human osteoclasts were differentiated from peripheral blood monocytes and cultured over a 17 day period. In separate experiments, human osteoblasts were differentiated from human mesenchymal stem cells isolated from bone chips collected during bone marrow donations, and cultured over 21 days. In these assays, cells were exposed to the key inflammatory cytokine involved with the cascade of the abovementioned conditions, tumour necrosis factor-α (TNFα), to represent an inflammatory environment in vitro. Cells were then treated with HDAC inhibitors (HDACi) that target the individual isoforms previously shown to be altered in pathological bone loss conditions, HDAC-1, −2, −5 and −7. Analysis of bone turnover through dentine resorptive measurements and bone mineral deposition analyses were used to quantify the activity of bone cells. Immunohistochemistry of tartrate resistant acid phosphatase (TRAP), WST-assay and automated cell counting was used to assess cell formation, viability and proliferation rates. Real-time quantitative PCR was conducted to identify alterations in the expression of anti- and pro-inflammatory chemokines and cytokines, osteoclastic and osteoblastic factors, in addition to multiplex assays for the quantification of cytokine/chemokine release in cell supernatant in response to HDACi treatments in the presence or absence of TNFα. TNFα stimulated robust production of pro-inflammatory cytokines and chemokines by PBMCs (IL-1β, TNFα, MCP1 and MIP-1α) both at the mRNA and protein level (p < 0 .05). HDACi that target the isoforms HDAC-1 and −2 in combination significantly suppressed the expression or production of these inflammatory factors with greater efficacy than targeting these HDAC isoforms individually. Suppression of HDAC-5 and −7 had no effect on the inflammatory cascade induced by TNFα in monocytes. During osteoclastic differentiation, TNFα stimulated the size and number of active cells, increasing the bone destruction observed on dentine slices (p < 0 .05). Targeting HDAC-1 and −2 significantly reduced bone resorption through modulation of the expression of RANKL signalling factors (NFATc1, TRAF6, CatK, TRAP, and CTR) and fusion factors (DC-STAMP and β3-integerin). Conversely, the anabolic activity of osteoblasts was preserved with HDACi targeting HDAC-5 and −7, significantly increasing their mineralising capacity in the presence of TNFαthrough enhanced RUNX2, OCN and Coll-1a expression. These results identify the therapeutic potential of HDACi through epigenetic regulation of cell activity, critical to the processes of inflammatory bone destruction

Bone loss creates a challenge to achieving fixation in revision TKR. Failure to achieve metaphyseal fixation is associated with failure in revision TKR. In the absence of cancellous bone for cement fixation, metaphyseal augments placed without cement have shown promise in achieving fixation. First generation augments were modular solid titanium sleeves attached to a taper at the base of the core implant. The introduction of tantalum with its favorable mechanical qualities markedly increased the utility and utilization of metaphyseal augments, with positive reports. These are either large augments where the bone is prepared with a burr, or later small cones placed with a cannulated broaching technique. Both have solved real problems, the first being limited by the reproducibility of bone preparation, and the second with excellent reproducibility of bone preparation but limited diameters. Other highly porous titanium surfaces have broadened the choices. Modern metaphyseal augments seek to add flexibility and options, specifically the use of offset stems. One tibial augment design features a reamed cone with a matching conical implant. Another option is based on an anatomic cone design with a single ream and a broached technique to optimise endosteal cortical bone contact. With each of these options, the augment can be placed wherever the remaining bone exists for fixation, even down to the metaphyseal-diaphyseal junction, and not limited to the area adjacent to the cut surface of bone. Once independent fixation is achieved, the intramedullary stem is cemented inside of it. Modern femoral augments are designed to sit either in the epiphyseal region, or the metaphysis. Cannulated reaming systems allow for preparation of complex asymmetrical double cone implants at the epiphysis. Metaphyseal implants are designed anatomically to sit deeper in the femoral bone, and can manage larger bony defects. Each system has benefits and compromises, and together they comprise increasingly powerful alternatives to manage extensive bone loss

Aim. Vascularized fibula flap is one of the available options in the management of bone loss that can follow cases of severe haematogenous osteomyelitis. The aim of this study was to evaluate the outcomes of this procedure in a pediatric population in a Sub-saharan setting. Method. The retrospective study focuses on the procedures done in the period between October 2013 and December 2016. Twenty-eight patients, 18 males and 10 females, were enrolled. The youngest was 2 years old, the oldest 13. The bones involved were tibia (13), femur (7), radius (5) and humerus (3). In 5 cases the fibula was harvested with its proximal epiphysis, whereas in 17 cases the flap was osteocutaneous and osseous in 6 cases. In most cases, operations for eradication of the infection were carried out prior to the graft. The flap was stabilized mainly with external fixators, rarely with Kirschner's wires or mini plate. No graft augmentation was used. Results. Graft integration was achieved in 24 cases. Three cases of early flap failure required the removal, while in one case complete reabsorption of the flap was noted a few months after the procedure. The follow-up period ranged from a minimum of 2 and half to a maximum of 6 years. Integration of the graft was obtained in a period of 4 months on average. The fibular flap with epiphysis had good functional outcomes with reconstruction of articular end. Early and delayed complications were observed. All grafts underwent a process of remarkable remodeling. No major problems were observed in the donor site, except for a transitory foot drop that resolved spontaneously. Conclusions. Reconstruction of segmental bone defects secondary to hematogenous osteomyelitis with vascularized fibula flap is a viable option that salvages and restores limb function. It can be safely used even in early childhood. The fibula can be harvested as required by the local conditions. When harvested with a skin island, bone loss and poor soft tissues envelope may be addressed concurrently. The procedure is long and difficult but rewarding. When surgical skills and facilities are available, it can be carried out even in settings located in low resources countries

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 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

Metaphyseal bone loss, due to loosening, osteolysis or infection, is common with revision total knee arthroplasty (TKA). Small defects can be treated with screws and cement, bone graft, and non-porous metal wedges or blocks. Large defects can be treated with bulk structural allograft, impaction grafting, or highly porous metal cones. The AORI classification of bone loss in revision TKA is very helpful with pre-operative planning. Type 1 defects do not require augments or graft—use revision components with stems. Type 2A defects should be treated with non-porous metal wedges or blocks. Type 2B and 3 defects require a bulk structural allograft or porous metal cone. Highly-porous metal metaphyseal cones are a unique solution for large bone defects. Both femoral (full or partial) and tibial (full, stepped, or cone+plate) cones are available. These cones substitute for bone loss, improve metaphyseal fixation, help correct malalignment, restore joint line, and permit use of a short cemented stem. The technique for these cones involve preparing the remaining bone with a high speed burr and rasp, followed by press-fit of the cone into the remaining metaphysis. The interface is sealed with bone graft and putty. The fixation and osteoconductive properties of the outer surface allow ingrowth and biologic fixation. The revision knee component is then implanted, with antibiotic-cement, into the porous cone inner surface, which provides superior fixation compared to cementing into deficient metaphyseal bone. There are several manufacturers that provide porous cones for knee revision, but the tantalum-“trabecular metal” cones have the largest and longest clinical follow-up. The advantages of the trabecular metal cone compared to allograft include: technically easier; biologic fixation; no resorption; and lower risk of infection. The disadvantages include: difficult extraction and intermediate-term follow-up. The author has reported the results of 33 trabecular metal cones (9 femoral, 24 tibial) implanted in 27 revision cases at 2–5.7 years follow-up. One knee (2 cones) was removed for infection. All but one cone showed osseointegration. Multiple other studies have confirmed these results. Trabecular metal cones are now the author's preferred method for the reconstruction of large bone defects in revision TKA

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

Open femoral fractures are uncommon, and there are very few reports in the literature which refer specifically to their management. The results of the treatment of 31 open femoral fractures with significant bone loss in 29 patients treated in a single Orthopaedic Trauma Unit were reviewed. All fractures underwent wound and bony debridement before skeletal stabilisation at restored femoral length, using primary locked intramedullary nailing or dynamic condylar screw fixation for diaphyseal or metaphyseal fractures respectively. Soft tissue closure was performed at 48 hours in the majority of cases, followed by elective bone grafting procedures for 13 of the fractures. All fractures achieved bony union at an average of 51 weeks (range 20-156 weeks). The time to fracture union and subsequent functional outcome were largely dependent upon the location, type and extent of the bone loss. Union was achieved more rapidly in fractures associated with wedge defects than those with segmental bone loss, and fractures with metaphyseal defects healed more rapidly than those of comparable size in the diaphysis. Metaphyseal wedge fractures did not require any further procedures to achieve union. Complications were more common in the fractures with greater bone loss, which included knee stiffness, delay to union, malunion and leg length discrepancy. One patient had a deep infection, treated by debridement. We have produced an algorithm for the treatment of these injuries, based upon our findings. We feel that satisfactory results can be achieved in most femoral fractures with bone loss, using appropriate initial debridement and modern methods of primary skeletal fixation at a restored femoral length, followed by soft tissue coverage procedures and elective bone grafting, as required

The primary objective of this study was to establish a safety profile for an all-arthroscopic anatomic glenoid reconstruction via iliac crest autograft augmentation for the treatment of shoulder instability with glenoid bone loss. Short-term clinical and radiological outcomes were also evaluated. This study involved a retrospective analysis of prospectively collected data for 14 patients (male 8, female 6) who were treated for shoulder instability with bone loss using autologous iliac crest bone graft between 2014 and 2018. Of 14 patients, 11 were available for follow-up. The safety profile was established by examining intra-operative and post-operative complications such as neurovascular injuries, infections, major bleeding, and subluxations. Assessment of pre-operative and post-operative Western Ontario Shoulder Instability (WOSI) index, radiographs, and CT scans comprised the evaluation of clinical and radiological outcomes. A good safety profile was observed. There was no occurrence of intraoperative complications, neurovascular injuries, adverse events, or major bleeding. One patient did develop an infection in the neurovascular injuries, adverse events, or major bleeding. One patient did develop an infection in the treated shoulder post-surgery. There were no subluxations or positive apprehension tests on clinical examination post-operatively. Short-term clinical outcomes were seen to be favorable WOSI scores at the most recent follow-up were significantly higher than pre-operative scores, with a mean increase of 39.6 ± 10.60 (p = 0.00055). The average follow-up for CT scan was 4.66 (SD± 2.33) months, where all patients showed bone graft union. Arthroscopic treatment of shoulder instability with bone loss via autologous iliac crest bone graft is shown to be a safe operative procedure that results in favorable short-term clinical and radiological outcomes. Further investigations must be done to evaluate the longevity of these positive health outcomes

INTRODUCTION:. Recent trends in total hip arthroplasty (THA) have resulted in the use of larger acetabular components to achieve larger femoral head sizes to reduce dislocation, and improve range of motion and stability. Such practices can result in significant acetabular bone loss at the time of index THA, increasing risk of anterior/posterior wall compromise, reducing component coverage, component fixation, ingrowth surface and bone stock for future revision surgery. We report here on the effects of increasing acetabular reaming on component coverage and bone loss in a radiographic CT scan based computer model system. METHODS:. A total of 74 normal cadaveric pelves with nonarthritic hip joints underwent thin slice CT scan followed by upload of these scans into the FDA approved radiographic analysis software. Utilizing this software package, baseline three-dimensional calculations of femoral head size and acetabular size were obtained. The software was used to produce a CT scan based model that would simulate reaming and placement of acetabular components in these pelves that were 125, 133 and 150% the size of the native femoral head. Calculations were made of cross sectional area bone loss from anterior/posterior columns, and loss of component coverage with increasing size. RESULTS:. Use of acetabular components that were 125, 133 and 150% the size of the native femoral head led to a average loss of 23, 27% and 33% loss of cross-sectional acetabular bone and an average 7, 16 and 27% loss of acetabular component coverage. CONCLUSION:. The CT scan/computer based model described here demonstrates that acetabular preparation and use of large components simply to gain larger femoral head size can result in significant bone loss and reduced component coverage. Operating hip surgeons attempting to utilize such large components must take great caution when attempting to maximize acetabular component size

Management of bone loss on both sides of the glenohumeral joint has been made much easier by the introduction of the reverse shoulder arthroplasty (RSA). While traditional posterior bone grafting and newer augmented glenoid components are still being used for Walch type B2 glenoids, there is movement and the trend towards using the reverse prosthesis with Bone Ingrowth Offset (BIO-RSA) techniques. Bone loss on the humeral side can be managed by the prosthesis itself, fresh matched or frozen proximal humerus allografts, femoral shaft allografts, or tibial strut allografts. Several cases will be shown to illustrate each technique