Introduction. Total hip arthroplasty (THR) is one of the most successful procedures performed today. Uncemented acetabular components have by and large replaced cemented cups. As such, optimal fixation, bony ingrowth with longevity, and safety is highly demanded. In this study, we look at the safety and efficacy of the Stryker® Trident PSL™ acetabular component based on radiographic and clinical analysis. Materials and Methods. We looked at 860 consecutive patients between 2003 and 2007. Of these, 231 consecutive patients had a minimum 5 year follow up. All cases were for degenerative joint disease (DJD), except 2 for dysplasia, 1 for avascular necrosis (AVN), 1 femoral neck nonunion. Average Hospital for Special Surgery (HSS) hip scores at final follow up were recorded. Radiographic analysis included classification based on Delee and Charnley's zones 1–3. Osseointegration was assessed based on presence of SIRCAB (stress induced reactive cortical hypertrophy of bone), demarcation around the implant, stress shielding, presence of radial trabeculae, absence of radiolucency, type of bearing, presence of preoperative protrusion, violation of Kohler's line. EBRA software was used to assess acetabular inclination and version. Results. Of 231 hip replacements analyzed, 114 were male, 117 were female. The average age was 63 (range 33–87); height was 67.5 inches; BMI was 27; 3 patients had a preoperative diagnosis of DDH, 2 had AVN, 1 femoral neck nonunion, and 1 case of rheumatoid arthritis (RA), with the remainder of patients diagnosed with DJD. cup abduction angle was 41.7° with average of 17.4° of anteversion. Average HSS functional score was excellent at latest follow up was 34, with most patients not relying on any assistive devices; There were no revisions performed due to mechanical failures or due to failure to osseointegrate. Complications include 1 infection (0.43%); and 4 dislocations (1.73%). Osseointegration was measured by separating the acetabulum into DeLee and Charnley zones and assessed by analyzing:. a). stress induced hypertrophic reaction of cortical bone (SIHRCaB): zone 1 (75.8%), zone 2 (11.7%), zone 3 (51.9%). b). Radial trabeculae: zone 1 (94.8%), zone 2 (93.5%), zone 3 (92.6%). c). Absence of radiolucency: zone 1 (96.1%), zone 2 (97%), zone 3 (96.1%). No association of bearing surfaces to survivorship was noted as metal femoral heads were used in 72.7% of cases while a ceramic bearing was used in 25.1%. Conclusion. The Trident PSL acetabular component was examined in a large, consecutive series by a single surgeon with a minimum 5–9 year follow up. We have demonstrated excellent radiographic osseointegration at latest follow up with no mechanical failures, high survivorship, and excellent clinical outcome scores. It continues to be a reliable option for primary acetabular reconstruction

Introduction. Long-term success of the cementless acetabular component has been depends on amount of bone ingrowth around porous coated surface of the implant, which is mainly depends on primary stability, i.e. amount of micromotion at the implant-bone interface. The accurate positioning of the uncemented acetabular component and amount of interference fit (press-fit) at the rim of the acetabulum are necessary to reduce the implant-bone micromotion and that can be enhancing the bone ingrowth around the uncemented acetabular component. However, the effect of implant orientations and amount of press-fit on implant-bone micromotion around uncemented acetabular component has been relatively under investigated. The aim of the study is to identify the effect of acetabular component orientation on implant-bone relative micromotion around cementless metallic acetabular component. Materials and Method. Three-dimensional finite element (FE) model of the intact and implanted pelvises were developed using CT-scan data [1]. Five implanted pelvises model, having fixed antiversion angle (25°) and different acetabular inclination angle (30°, 35°, 40°, 45° and 50°), were generated in order to understand the effect of implant orientation on implant-bone micromotion around uncemented metallic acetabular component. The CoCrMo alloy was chosen for the implant material, having 54 mm outer diameter and 48 mm bearing diameter [1]. Heterogeneous cancellous bone material properties were assigned using CT-scan data and power law relationship [1], whereas, the cortical bone was assumed homogeneous and isotropic [1]. In the implanted pelvises models, 1 mm diametric press-fit was simulated between the rim of the implant and surrounding bone. Six nodded surface-to-surface contact elements with coefficient of friction of 0.5 were assigned at the remaining portion of the implant–bone interface [1]. Twenty-one muscle forces and hip-joint forces corresponds to peak hip-joint force of a normal walking cycle (13%) were used for the applied loading condition. Fixed constrained was prescribed at the sacroiliac joint and pubis-symphysis [1]. A submodelling technique was implemented, in order to get more accurate result around implant-bone interface [1]. Results and Discussions. The peak implant-bone sliding interfacial micromotion was observed around 75 microns around superior and supero-posterior regions of the acetabulum, whereas, micromotion was below 50 microns around other regions (area). As compared to other regions, less implant-bone micromotions were observed at the central region of the acetabulum and anterior part of the acetabulum, where micromotions were varied in the range between 5 microns to 30 microns. Although, the generated peak implant-bone sliding micromotion around the uncemented acetabulum was not vary notably due to change in inclination angle of the acetabular component, changes in patterns of implant-bone micromotions were observed and as shown [Fig.1]. Results of the present study indicated that the positioning of the uncemented acetabular component have influence on patterns of implant-bone micromotion and that might have influence on bone ingrowth and long-term success of uncemented acetabular component

Background

Radiostereometric Analysis (RSA) is an accurate measure of implant migration following total joint replacement surgery. Early implant migration predicts later loosening and implant failure, with RSA a proven short-term predictor of long-term survivorship. The proximal migration of an acetabular cup has been demonstrated to be a surrogate measure of component loosening and the associated risk of revision. RSA was used to assess migration of the R3 acetabular component which utilises an enhanced porous ingrowth surface. Migration of the R3 acetabular component was also assessed when comparing the fixation technique of the femoral stems implanted.

Abstract. Optimal acetabular component position in Total Hip Arthroplasty is vital for avoiding complications such as dislocation and impingement, Transverse acetabular ligament (TAL) have been shown to be a reliable landmark to guide optimum acetabular cup position. Reports of iliopsoas impingement caused by acetabular components exist. The Psoas fossa (PF) is not a well-regarded landmark for Component positioning. Our aim was to assess the relationship of the TAL and PF in relation to Acetabular Component positioning. A total of 22 cadavers were implanted on 4 occasions with the an uncemented acetabular component. Measurements were taken between the inner edge of TAL and the base of the acetabular component and the distance between the lower end of the PF and the most medial end of TAL. The distance between the edge of the acetabular component and TAL was a mean of 1.6cm (range 1.4–18cm). The distance between the medial end of TAL and the lowest part of PF was a mean of 1.cm (range 1,3–1.8cm) It was evident that the edge of PF was not aligned with TAL. Optimal acetabular component position is vital to the longevity and outcome following THA. TAL provides a landmark to guide acetabular component position. However we feel the PF is a better landmark to allow appropriate positioning of the acetabular component inside edge of the acetabulum inside the bone without exposure of the component rim and thus preventing iliopsoas impingement at the psoas notch and resultant groin pain

A well-fixed uncemented acetabular component is most commonly removed for chronic infection, malposition with recurrent dislocation, and osteolysis. However, other cups may have to be removed for a broken locking mechanism, a bad “track record”, and for metal-on-metal articulation problems. Modern uncemented acetabular components are hemispheres which have 3-dimensional ingrowth patterns. Coatings include titanium or cobalt-chromium alloy beads, mesh, and now the so-called “enhanced coatings”, such as tantalum trabecular metal, various highly porous titanium metals, and 3-D printed metal coatings. These usually pose a problem for safe removal without fracture of the pelvis or creation of notable bone deficiency. Preoperative planning is essential for safe and efficient removal of these well-fixed components. Strongly consider getting the operative report, component “stickers”, and contacting the implant manufacturer for information. There should a preoperative check list of the equipment and trial implants needed, including various screwdrivers, trial liners, and a chisel system. The first step in component removal is excellent 360-degree exposure of the acetabular rim, and this can be accomplished by several approaches. Then, the acetabular polyethylene liner is removed; a liner that is cemented into a porous shell can be “reamed out” using a specific device. Following this, any central or peripheral screws are removed; broken or stripped screw heads add an additional challenge. A trial acetabular liner is placed, and an acetabular curved chisel system is used. There are two manufacturers of this type of system. Both require the known outer acetabular diameter and the inner diameter of the trial liner. With the curved chisel system and patience, well-fixed components can be safely removed, and the size of the next acetabular component to be implanted is usually 4mm larger than the one removed. There are special inserts for removal of monobloc metal shells. Remember that removal of these well-fixed components is more difficult in patients compared to models, and is just the first step of a successful acetabular revision

Highly crosslinked polyethylene (XLPE) was introduced to decrease peri-prosthetic osteolysis related to polyethylene wear, a major reason for revision of total hip arthroplasty. There are few reports of wear and osteolysis at 10 years post-operatively. We asked the following questions: (1) What are the linear and volumetric wear rates of one remelted XLPE at 10–14 years using the Martell method? (2) What is the relationship between volumetric wear, femoral head size, and osteolysis? (3) What is the incidence of osteolysis using conventional radiographs with Judet views and the Martell method?. Methods We evaluated a previously reported cohort of 84 hips (72 patients) with one design of an uncemented acetabular component and one electron-beam irradiated, remelted XLPE at a mean follow-up of 11 years (range 10 to 14 years). Measurements of linear and volumetric wear were performed in one experienced laboratory by the Martell method and standard radiographs, with additional Judet views, were used to detect peri-prosthetic osteolysis. Statistical analysis of wear and osteolysis compared to head size was performed. Results The mean linear wear rate by the first-to-last method was 0.024 mm/year (median, 0.010 mm/year) and the mean volumetric wear rate by this method was 12.2 mm. 3. /year (median, 3.6 mm. 3. /year). We found no association between femoral head size and linear wear rate. However, there was a significant relationship between femoral head size and volumetric wear rates, with 36/40 mm femoral heads having significantly higher volumetric wear (p=0.02). Small osteolytic lesions were noted in 12 hips (14%), but there was no association with head size, acetabular component position, or linear or volumetric wear rates. Conclusion This uncemented acetabular component and this particular remelted XLPE had low rates of linear and volumetric wear. Small osteolytic lesions were noted at 10 to 14 years, but were not related to femoral head size, linear or volumetric wear rates

Uncemented acetabular component fixation remains the gold standard for managing various defects in the revision hip setting. Multiple series have demonstrated over 90% ten-year survivorship of these constructs. Modern “enhanced” metals such as trabecular tantalum and titanium continue to perform well and are growing in popularity. So called “jumbo” cups, diameters >=62mm in females and >=66mm in males have demonstrated excellent survivorship. Good bony support with viable bone and stable initial fixation is necessary for long-term success. It is unknown how much remaining bone is necessary for reliable ingrowth with modern enhanced metals. The location of the remaining bone is probably more important than the absolute amount remaining. Occasionally, the uncemented cup must be augmented with metal augments or even a so-called “cup cage” construct. Even in these situations, the uncemented cup remains the workhorse of revision THA due to its ingrowth potential and excellent track record. Augments are commercially available in various shapes and sizes to assist in the management of cavitary, segmental and combined defects while restoring the desired cup position. Trials are available to ensure good approximation of the augment to remaining bone. The constructs are typically “unitised” to the cup via bone cement. Available data show excellent survivorship of augmented constructs for these challenging reconstructions

The dual mobility design concept for acetabular components is intended to reduce the risk of dislocation and increase range of motion, but the wear pattern of this design is unclear and may have implications in implant fixation. Additionally, the solid back cups do not have the option for supplementary screw fixation, providing an additional smooth articulating surface for the liner to move against. The objective of this study was to assess cup fixation by measuring implant migration as well as proximal femoral head penetration to evaluate wear performance. Thirty subjects were recruited in a consecutive series prospective study and received dual mobility uncemented acetabular components with mobile bearing polyethylene liners through a direct lateral approach. Femoral stems were cemented or uncemented. All subjects had 28 mm femoral heads. The femur, acetabulum, and non-articulating surface of the mobile polyethylene liner were marked with tantalum beads. Radiostereometric analysis (RSA) exams were performed post-operatively and at 6 weeks, 3 months, 6 months, 1 year, 2 years, and 3 years. Oxford 12 Hip and Satisfaction questionnaire responses were recorded. Mobile bearing motion was assessed under fluoroscopy for a single case under loaded and unloaded conditions. Twenty-nine subjects (17 female) proceeded to surgery. Subjects were 63±11 years of age with BMIs of 28±4.7 kg/m2. Cup migration reached 0.16 ± 0.31 mm of proximal translation and 0.29±1.03 degrees of sagittal rotation at three years. A single individual had more than 3 degrees of cup rotation, occurring by 6 months and not substantially increasing after this time. Proximal translation was low for this subject. Wear of the highly cross-linked mobile bearings was 0.18 ± 0.30 mm of proximal femoral head penetration from 0 to 3 years. The mean wear rate from 1 to 3 years was 0.02 mm/year. One subject was an outlier for wear, with more than 1 mm of femoral head penetration at 1 year. However, wear did not increase after 1 year for this subject and cup migrations were below average for this individual. Similarly, the outlier for cup rotation had below average wear. Satisfaction (out of 100%) improved from 25±27% to 96±7% pre-operatively to 3 years post-operatively. Oxford 12 scores (best possible score of 48) improved from 21±7 to 43±7 over the same period. The fluoroscopic case study demonstrated visible motion of the mobile bearing during hip rotation tasks. The overall migration of the cup was low and demonstrated favorable patterns suggesting low risk of aseptic loosening. Wear rates are also within the expected range of 0 to 0.06 mm/year for highly cross-linked polyethylene. The combination of low subsidence and low sagittal rotations of the cup, and low wear of the polyethylene are favorable predictors of good long-term performance

Uncemented acetabular component fixation remains the gold standard for managing various defects in the revision hip setting. Multiple series have demonstrated over 90% ten-year survivorship of these constructs. Modern “enhanced” metals such as trabecular tantalum and titanium continue to perform well and are growing in popularity. So called “jumbo” cups, diameters >=62mm in females and >=66mm in males have demonstrated excellent survivorship. Good bony support with viable bone and stable initial fixation is necessary for long-term success. It is unknown how much remaining bone is necessary for reliable ingrowth with modern enhanced metals. The location of the remaining bone is probably more important than the absolute amount remaining. Occasionally, the uncemented cup must be augmented with metal augments or even a so-called “cup cage” construct. Even in these situations, the uncemented cup remains the workhorse of revision THA due to its ingrowth potential and excellent track record. Augments are commercially available in various shapes and sizes to assist in the management of cavitary, segmental and combined defects while restoring the desired cup position. Trials are available to ensure good approximation of the augment to remaining bone. The constructs are typically “unitised” to the cup via bone cement. Available data show excellent survivorship of augmented constructs for these challenging reconstructions

Introduction. Uncemented porous coated acetabular components have gained more research emphasis in recent years compared to their cemented counterparts, largely owing to the natural biological fixation they offer. Nevertheless, sufficient peri-prosthetic bone ingrowth is essential for long-term fixation of such uncemented acetabular components. The phenomenon of bone ingrowth can be predicted based on mechanoregulatory principles of primary bone fracture healing. Literature review reveals that the surface texture of implant plays a major role in implant-bone fixation mechanism. A few insilico models based on 2-D microscale finite elements (FE) were reported in literatures to predict the influence of surface texture designs on peri-prosthetic bone ingrowth. However, most of these studies were based on FE models of dental implants. The primary objective of this study, therefore, is to mechanobiologically predict the influence of surface texture on bone- ingrowth in acetabular components considering a novel 3-D mesh-shaped surface texture on the implant. Materials/Methods. The 3-D microscale model [Fig.1] of implant-bone interface was developed using CATIA. ®. V5R20 software (DassaultSystèmes, France) and was modelled in ANSYS V15.0 FE software (Ansys Inc., PA, USA) using coupled linear elastic ten-noded tetrahedral finite elements. The model consists of cast-inbeaded mesh textured implant having finely meshed inter-bead spacing. Linear, elastic and isotropic material properties considering Young's modulus of 210 GPa and Poisson's ratio of 0.3 for stainless steel implant were employed in the model. Boundary of bone was assumed to be rich in Mesenchymal Stem Cells(MSC) with periodic boundary conditions at contralateral surfaces. The linear elastic material properties in the model were updated iteratively through a tissue differentiation algorithm that works on the principle of mechanotransduction driven by local mechanical stimuli, e.g. hydrostatic pressure and equivalent deviatoric strain. Results. Results indicate that bone ingrowth is inhibited upon increasing the inter-bead spacing and upon decreasing the bead aspect ratio. It has been observed that there is a predominant influence of bead spacing diameter on the peri-acetabular bone ingrowth. The increase in bead spacing diameter has led to increased bead height that is found to promote higher bone ingrowth with an increase in average Young's modulus of neo-tissue layer. Conclusions. The present study focussed on the development of a new texture on the implant surface and to study the influence of surface texture on bone-ingrowth in acetabular components. Since there is a promising increase in average Young's modulus of the newly formed tissue layer, it predicts the increase in stiffness of the newly formed tissue. The increase in tissue stiffness reveals that, there is not much inhibition in bone ingrowth after the employment of the acetabular implant. The numerical study based on mechanoregulatory algorithm considering the appropriate mechanical stimuli responsible for bone ingrowth, reveals that, compared to hemispherical beaded surface texture, mesh shaped surface texture provides an improved fixation of the acetabular component. For any figures or tables, please contact the authors directly

Background. The optimal surgical treatment for osteonecrosis of the femoral head has yet to be elucidated. To evaluate the role of femoral fixation techniques in hip resurfacing, we present a comparison of the results for two consecutive groups: Group 1 (75 hips) received hybrid hip resurfacing implants with a cemented femoral component; Group 2 (103 hips) received uncemented femoral components. Both groups received uncemented acetabular components. Methods. We retrospectively analyzed our clinical database to compare failures, reoperations, complications, clinical results, metal ion test results, and x-ray measurements. Using consecutive groups caused time interval bias, so we required all Group 2 patients be at least two years out from surgery; we compared results from two years and final follow-up. Results. Patient groups matched similarly in age, BMI, and percent female. Despite similar demographics, the uncemented, Group 2 cases showed a lower raw failure rate (0% vs. 16% p<0.0001), a lower 2-year failure rate (0% vs. 7%, p=0.04), and a superior 8-year implant survivorship (100% vs. 91%, log-rank p=0.0028, Wilcoxon p=0.0026). In cases that did not fail, patient clinical (p=0.05), activity (p=0.02), and pain scores (p=0.03), as well as acetabular component position (p<0.0001), all improved in Group 2, suggesting advancements in surgical management. There were no cases of adverse wear related failure in either group. Conclusions. This study demonstrates a superior outcome for cases of osteonecrosis with uncemented hip resurfacings compared to cases employing hybrid devices

A study by Harris reported a 40% incidence of femoral and acetabular dysplasia in routine idiopathic osteoarthritic patients. Due to pediatric screening in the United States, today most cases are minimally dysplastic requiring little modification from standard total hip surgical techniques. As the degree of dysplasia increases numerous anatomic distortions are present. These include high hip centers, relative acetabular retroversion, soft bone in the true acetabular area, increased femoral neck anteversion and relative posteriorly positioned greater trochanters, metaphyseal/diaphyseal size mismatch, and small femoral canals. Total hip replacements for these patients have known higher risks for earlier loosening, dislocation, and neurovascular injuries. Use of medialised small uncemented acetabular components placed in the anatomic acetabulum, modular uncemented femoral components, and diaphyseal rotational and shortening osteotomies has become a preferred method of treatment. In 2007, we reported our experience with this technique in 23 cases utilizing a subtrochanteric femoral osteotomy with a 5–14 year follow-up. There were 4 Crowe I, 3 Crowe II, 5 Crowe III, and 11 Crowe IV cases. All osteotomies healed. There were no femoral components revised. In most cases, small (mean 46 mm) hemispherical components were used without bulk allografts in all but 5 early cases. One acetabular component was revised for a recalled component. 3 acetabular liners were revised for wear (2 were very small cups with 4.7 mm poly thickness). Four patients sustained dislocations, with 2 closed and 2 open reductions. There were no neurovascular injuries. The Crowe classification is commonly used to preoperatively classify the degree of dysplasia. However, there are large variations in these anatomic distortions within each class, so it is difficult to preoperatively plan the acetabular component size needed and if one will need to do shortening and/or rotational osteotomy. So the surgeon needs to be prepared for these cases with smaller acetabular components and be prepared to perform a femoral osteotomy

Although the vast majority of fractures of the proximal femur will heal with well-done internal fixation, occasionally failure of fixation will occur. Having effective salvage options is important to restore function and minimise complications. In general, it is logical to separate salvage options into those for fractures of the femoral neck, and those for fractures of the intertrochanteric region. Additionally, patient age and remaining bone stock should be considered. Femoral neck fracture fixation failure salvage, young patients: All efforts are focused on preserving the native femoral neck. Valgus producing osteotomy is typically indicated, and can be successful even with small patches of AVN. Femoral neck fracture fixation failure salvage, older patients: Total hip arthroplasty is generally most predictable. Be prepared for very poor bone quality. Supplement uncemented acetabular component with multiple screws. Be prepared to cement femoral component, if necessary. Intertrochanteric fracture fixation failure salvage, young patients: Repeat internal fixation attempts with fixed angle devices (such as a 95-degree blade plate) and bone grafting generally preferred. Avoid varus of proximal fragment and target inferior femoral head bone. Intertrochanteric fracture fixation failure salvage, older patients: Total hip arthroplasty preferred. Long stems to bypass femoral shaft stress risers and “calcar replacement” stems may be necessary due to proximal bone defects. Trochanteric fixation must be stable. Results are generally good but trochanteric complaints are common

Although the vast majority of fractures of the proximal femur will heal with well-done internal fixation, occasionally failure of fixation will occur. Having effective salvage options is important to restore function and minimise complications. In general, it is logical to separate salvage options into those for fractures of the femoral neck, and those for fractures of the intertrochanteric region. Additionally, patient age and remaining bone stock should be considered. Femoral neck fracture fixation failure salvage, young patients: All efforts are focused on preserving the native femoral neck. Valgus producing osteotomy is typically indicated, and can be successful even with small patches of AVN. Femoral neck fracture fixation failure salvage, older patients: Total hip arthroplasty is generally most predictable. Be prepared for very poor bone quality. Supplement uncemented acetabular component with multiple screws. Be prepared to cement femoral component, if necessary. Intertrochanteric fracture fixation failure salvage, young patients: Repeat internal fixation attempts with fixed angle devices (such as a 95 degree blade plate) and bone grafting generally preferred. Avoid varus of proximal fragment and target inferior femoral head bone. Intertrochanteric fracture fixation failure salvage, older patients: Total hip arthroplasty preferred. Long stems to bypass femoral shaft stress risers and “calcar replacement” stems may be necessary due to proximal bone defects. Trochanteric fixation must be stable. Results are generally good but trochanteric complaints are common

Introduction. The dual mobility design concept for acetabular liners is intended to reduce the risk of dislocation and increase range of motion, but the wear pattern of this design is unclear and may have implications in implant fixation. Additionally, the solid back cups do not have the option for supplementary screw fixation, providing an additional smooth articulating surface for the liner to move against. The objective of this study was to assess cup fixation by measuring implant migration. A secondary objective was to evaluate the mobile bearing motion after rotating the hip. Methods. Thirty subjects were recruited in a consecutive series prospective study and received Anatomic Dual Mobility (Stryker Orthopedics) uncemented acetabular components with mobile bearing polyethylene liners through a direct lateral approach. Femoral stems were cemented (Exeter) or uncemented (Accolade, Stryker Orthopedics). The femur, acetabulum, and non-articulating surface of the polyethylene liner were marked with tantalum beads. Radiostereometric analysis (RSA) exams were performed post-operatively and at 6 weeks, 3, 6, months, and at 1 year. At the 1 year exam, a frog leg RSA exam was performed to assess the mobility of the cup compared to its position during a supine exam. Results. Proximal translation of the cup was 0.16 ± 0.28 mm (range −0.18 to 0.92 mm) and sagittal rotation was 0.08 ± 0.86 degrees (range −1.81 to 2.18 degrees) at 1 year. Analysis of the motion of the mobile bearing liner during the frog leg RSA exam showed total motions of between 0.10 to 5.58 mm (maximum total point motion). Discussion & Conclusions. The migration of the cup has a low group average and is on track to be in the “acceptable” range as defined by Pijls et al. [1] of less than 0.2 mm of subsidence at 2 years. The combination of low subsidence and low sagittal rotations of the cup are favorable predictors of good long-term performance [2]. The wide range of motions of the mobile bearing suggest that in some patients the liner is moving freely, while in a subset of subjects there is no motion. The implications of this in terms of the generation of wear particles and affect on implant migration will be monitored to 3 years

Although the vast majority of fractures of the proximal femur will heal with well-done internal fixation, occasionally failure of fixation will occur. Having effective salvage options is important to restore function and minimize complications. In general, it is logical to separate salvage options into those for fractures of the femoral neck, and those for fractures of the intertrochanteric region. Additionally, patient age and remaining bone stock should be considered. Femoral neck fracture fixation failure salvage, young patients: All efforts are focused on preserving the native femoral neck. Valgus producing osteotomy is typically indicated, and can be successful even with small patches of AVN. Femoral neck fracture fixation failure salvage, older patients: Total hip arthroplasty is generally most predictable. Be prepared for very poor bone quality. Supplement uncemented acetabular component with multiple screws. Be prepared to cement femoral component if necessary. Intertrochanteric fracture fixation failure salvage, young patients: Repeat internal fixation attempts with fixed angle devices (such as a 95 degree blade plate) and bone grafting generally preferred. Avoid varus of proximal fragment and target inferior femoral head bone. Intertrochanteric fracture fixation failure salvage, older patients: Total hip arthroplasty preferred. Long stems to bypass femoral shaft stress risers and “calcar replacement” stems may be necessary due to proximal bone defects. Trochanteric fixation must be stable. Results are generally good but trochanteric complaints are common

Major bone loss involving the acetabulum can be seen during revision THA due to component loosening, migration or osteolysis and can also occur as a sequela of infected THA. Uncemented porous ingrowth components can be used for reconstruction of the vast majority of revision cases, where smaller segmental or cavitary defects are typically present. But when stable structural support on host bone is lacking, highly porous metal acetabular augments have been described as an alternative to large structural allograft, avoiding the potential for later graft resorption and the resulting loss of mechanical support that can follow. The fundamental concept behind these acetabular augments is the provision of critical additional fixation, structural support and increased contact area against host bone over the weeks following surgery while the desired ingrowth into porous implant surfaces is occurring. Three separate patterns of augment placement have been utilised in our practice since the development of these implants a decade ago: Type 1 – augment screwed onto the superolateral acetabular rim in a “flying buttress” configuration for treatment of a segmental rim defect, Type 2 – augment placed superiorly against host and then fixed (with cement) to the acetabular component adjacent to the cup to fill a mainly elliptical cavitary defect, and Type 3 – augment(s) placed medial to the cup to fill a protrusio type cavitary or combined cavitary segmental defect of the superomedial or medial wall, and allow peripheral cup placement against the still intact acetabular rim. In all cases the acetabular component and augment interface is fixed together with cement, with care to prevent any cement extrusion between any implant and the bone. When possible, we now prefer to place the acetabular component first and fix it provisionally with 2 or more screws, and then place the augments second as this is technically quicker and easier. This order of insertion is only possible though in type 1 and a few select type 2 cases. Type 3 cases always require placement of one or more augments first, before cup insertion. Supplemental cancellous bone graft is used routinely, but the need for structural bone is avoided. Highly porous metal acetabular augments are an infrequently needed, but extremely valuable, versatile and reliable adjunctive fixation method for use with uncemented acetabular components during complex revision THA associated with major bone deficiency. Smaller (often female) patients are more likely to require this approach as reaming away defects to allow insertion of a jumbo cup is more difficult in small patients with a smaller AP dimension to the acetabular columns and less local bone for implant support. Intermediate term durability and apparent radiographic incorporation has been very good despite the complex reconstructions originally required. This technique can allow the avoidance of structural bone grafting for even the most massive of bone defect problems, but additional followup is needed to see how durable these encouraging results are over the longer term

Young patients have been reported to have a higher risk of revision following total hip arthroplasty than older cohorts. This was attributed to the higher activity level which led to increased wear, osteolysis, and component fracture. We prospectively assessed the clinical results, wear and osteolysis, the incidence of squeaking, and the survivorship of ceramic on ceramic THA in patients younger than 50 years (mean age of 42 [18–50] years). The series included 425 THAs in 370 patients with 368 hips followed for a minimum of 2 years (mean 7.1 years, range 2–14 years). All patients received uncemented acetabular components with flush-mounted acetabular liners using an 18 degree taper. No osteolysis was observed in any uncemented construct. There was osteolysis around one loose cemented femoral component. The survivorship for reoperation for implant revision was 96.7%. There were only two acetabular liner fractures (0.47%) and one femoral head fracture (0.24%). Two of the three fractures involved a fall from a significant height. There were no hip dislocations. Five patients (1.17%) noted rare or occasional squeaking. None had reproducible squeaking. In summary, the current study shows that ceramic-on-ceramic THAs in the young patient population are extremely reliable with a very low revision rate and an absence of wear-induced osteolysis. In addition, it shows that both bearing fracture in this young patient population typically occurs with polytrauma and squeaking issues that have been raised relative to ceramic bearings occur very rarely with the flush-mounted ceramic liner design used in this study

Restoration of an anatomical hip centre frequently requires limb lengthening, which increases the risk of nerve injury in the treatment of Crowe 4 DDH. The objective was to perform a prospective evaluation of SDTSO with Cemented Exeter Femoral Component. 15 female patients (18 hips – 3 bilateral) with a mean age at time of operation of 51 years were followed-up for a mean of 77 months (11 to 133). 16 cemented and 2 uncemented acetabular components were implanted. Exeter cemented DDH stems were used in all cases. No patient was lost to follow-up. Charnley-d'Aubigné-Postel scores for pain, function and range of movement were improved from a mean of 2, 2, 3 to 5, 4, 5 respectively. One osteotomy failed to unite at 14 months and was revised successfully. Clinical healing was achieved at a mean of 6 months and radiological at a mean of 9 months. The mean length of the excised segment was 3cm and the mean true limb lengthening was 2cm. A 3.5mm DCP plate with unicortical screws was used to reduce the osteotomy, and intramedullary autografting was performed in all cases. Mean subsidence was 1mm and no stem was found loose at the latest follow-up. No sciatic nerve palsy was observed and no dislocation. Cemented Exeter femoral components perform well in the treatment of Crowe IV DDH with SDTSO. Transverse osteotomy is necessary to achieve derotation and reduction can be maintained with a DCP plate. Intramedullary autografting prevents cement interposition at the osteotomy site

Large bearing surfaces are appealing in total hip arthroplasty (THA) as they may help create a greater range of impingement free motion and reduce the risk of dislocation. However, attempts to achieve this with a metal bearing surface have been blighted by adverse reactions to metal debris. Ceramic bearings have a good long-term track record in more conventional head sizes, and manufacturing techniques now permit the use of larger ceramic bearing surfaces using monoblock uncemented acetabular components. In this study, we are reviewing the early results of the Maxera® acetabular component (Zimmer, Indiana) at our institution. All data was collected prospectively. Maxera® acetabular component is a Titanium (Ti) shell with plasma sprayed Ti for the osteointegrative surface. Delta ceramic liner is inserted & locked into the cup shell by the manufacturer (non-modular). With the Maxera cup system, the bearing diameter is dictated by the acetabular component size. Acetabular components (AC) of 46 and 48 mm have a bearing diameter (BD) of 36 mm, AC of 50 and 52 mm: have a 40 mm BD, AC of 54 and 56 mm: have a BD of 44 mm and AC of 58–64: have a 48mm BD. Delta ceramic femoral head size of 44 and 48 mm have a modular Ti sleeve between the head and femoral stem trunnion. Femoral head sizes of 36 and 40 mm have no Ti sleeve. All THA had an uncemented femoral stem. Implants were inserted with a posterior approach. Patients were reviewed at 6 weeks, 6 months and then annually with radiographs. Clinical function was evaluated using WOMAC and UCLA scores along with joint perception questionnaires. Five hundred components have been implanted in 442 patients (250 women, 192 men) with a mean age of 55, (min 17, max 80) and a mean BMI of 26.9 (min 17.8, max 51). The mean acetabular size was 54 (min 46, max 64), leading to a mean femoral head size of 44. At a minimum of two years follow-up (mean 3.8 years): 5 patients have been revised, 4 secondary to undetected intraoperative fracture of the femur and only one due to early displacement of a Maxera® cup (0.2%). Five patients reported a mild squeaking; two reported clicking and one patient presented with a symptomatic heterotopic ossification. The WOMAC score improved significantly post-operatively, (57.4 compared to 4.4 post-operatively, p<0.001). The mean post-operative UCLA score was 6.9. Sixty percent (60.6%) of patients rated their joint perception as either “natural” or “artificial without limitation”. two patients (0.4%) suffered a dislocation after high velocity trauma without recurrence after closed reduction. No ceramic component fracture was recorded. This prospective study shows that this monoblock acetabular component provides an easy implantation with minimal complications. The ceramic bearing surface provides good clinical function and joint perception. Bearing surfaces of this design may provide an alternative to large head metal on metal (MoM) implants without the side effects of metal debris/ions