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

Aims

The purpose of this study was to evaluate whether an innovative templating technique could predict the need for acetabular augmentation during primary total hip arthroplasty for patients with dysplastic hips.

In primary total hip arthroplasty (THA) for patients with Crowe II or higher classes developmental dysplasia of the hip (DDH) or rapidly destructive coxopathy (RDC), the placement of the cup can be challenging due to superior and lateral acetabular bone defects. Traditionally, bone grafts from resected femoral heads were used to fill these defects, but bulk graft poses a risk of collapse, especially in DDH with hypoplastic femoral heads or in RDC where good quality bone is scarce. Recently, porous metal augments have shown promising outcomes in revision surgeries, yet reports on their efficacy in primary THA are limited. This study retrospectively evaluated 27 patients (30 hips) who underwent primary THA using cementless cups and porous titanium acetabular augments for DDH or RDC, with follow-up periods ranging from 2 to 10 years (average 4.1 years). The cohort included 22 females (24 hips) and 5 males (6 hips), with an average age of 67 years at the time of surgery. The findings at the final follow-up showed no radiographic evidence of loosening or radiolucency around the cups and augments, indicating successful biological fixation in all cases. Clinically, there was a significant improvement in the WOMAC score from an average of 39.1±14.7 preoperatively to 5.1±6.4 postoperatively. These results suggest that the use of cementless cups and porous titanium acetabular augments in primary THA for DDH and RDC can lead to high levels of clinical improvement and reliable biological fixation, indicating their potential as a viable solution for managing challenging acetabular defects in these conditions

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. Technique: Three separate patterns of augment placement have been utilised in our practice since the development of these implants: 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. Results: From 2000 through 2007, porous tantalum acetabular augments were used very selectively in 85 revision THA procedures out of total of 1,789 revision hip cases performed at our institution in that time frame. All cases had associated massive acetabular deficiency precluding stable mechanical support for a cup alone. Fifty-eight hips had complete radiographic as well as clinical follow at minimum 5 years. The majority of patients had either Paprosky type 3A defects (28/58, 48%) or 3B defects (22/58, 38%). Ten out of 58 had pre-operative pelvic discontinuities. At 5 years, 2/58 (3%) were revised for aseptic loosening and another 6/58 demonstrated incomplete radiolucencies between the acetabular shell and zone 3. One of the revised cups and 5 of 6 of the cups with radiolucencies had an associated pelvic discontinuity. Summary: 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. 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

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. 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 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 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. From 2000 through 2007, porous tantalum acetabular augments were used very selectively in 85 revision THA procedures out of total of the 1,789 revision hip cases performed at our institution. All cases had associated massive acetabular deficiency precluding stable mechanical support for a cup alone. Fifty-eight hips had complete radiographic and clinical follow at minimum 5 years. The majority of patients had either Paprosky type 3A defects (28/58, 48%) or 3B defects (22/58, 38%). Ten out of 58 had pre-operative pelvic discontinuities. Three separate patterns of augment placement were utilised: Type 1 - augment screwed onto the superolateral acetabular rim (21%), Type 2 – augment fixed to the acetabular component adjacent to the cup to fill a mainly elliptical cavitary defect (34%), and Type 3 – augment(s) placed medial to the cup to fill a protrusio type cavitary or combined cavitary segmental defect of the superomedial medial wall (45%). At 5 years, 2/58 (3%) were revised for aseptic loosening and another 6/58 demonstrated incomplete radiolucencies between the acetabular shell and zone 3. One of the revised cups and 5 of 6 of the cups with radiolucencies had an associated pelvic discontinuity. 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 patients are more likely to require this approach as reaming away defects to allow insertion of a jumbo cup is more difficult 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

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

Tantalum is a pure metallic element and is attractive for use in orthopaedic implants because it is one of the most biocompatible metals available for implant fabrication. The potential advantages for the use of porous tantalum in total hip arthroplasty include:. excellent bone and tissue ingrowth observed histologically;. direct polyethylene intrusion into the metal substrate. This allows the elimination of any potential backside wear in the monoblock cup;. The two-piece design consist of a tantalum shell with screw holes for fixation into the dome of the ilium and posterior column. A polyethylene liner is cemented into the tantalum shell to eliminates backside motion. In addition, acetabular augments of porous tantalum have been developed for use in restoration of major bone deficiencies. Prospective study on a case serie of 113 THA’s performed by two surgeons in a single institution. From 2000 to December 2003, 113 hips have undergone arthroplasty using porous tantalum implants consisting of 54 primary hip arthroplasties and 59 revision THA’s. The patients where evaluated clinical and radiographically every 3 month during the first year, and after yearly. Mean patient age was 64,2 years, (range 44–87); with 59% males and 41% females. No patients died or lost to follow-up. No further surgeries of the involved hip. No radiographic signs of loosening of the acetabular component according to the criteria of Hodgkinson et al. No problems specifically from the use of acetabular augments or extra screws has been noted. Of the revision series, a total of 16 cases have received acetabular augments. Complications included 1 superficial infection, 2 dislocations. No vasculonervous complication; and in 2 cases technical difficulties to achieve good fixation due to ethiology of the THA (desarthrodesis). The average Harris hip score improved from 48 to 89 following primary surgery. Tantalum acetabular components for primary and revision hip surgery have performed well for up to 3 years, and have excellent stability. The two-piece acetabular shell and augments permits the reconstruction of every acetabular bone defect

Tantalum is a pure metallic element and is attractive for use in orthopaedic implants because it is one of the most biocompatible metals available for implant fabrication. The potential advantages for the use of porous tantalum in total hip arthroplasty include:. excellent bone and tissue in growth observed histologically;. direct polyethylene intrusion into the metal substrate. This allows the elimination of any potential backside wear in the monoblock cup;. The two-piece design consist of a tantalum shell with screw holes for fixation into the dome of the ilium and posterior column. A polyethylene liner is cemented into the tantalum shell to eliminates backside motion. In addition, acetabular augments of porous tantalum have been developed for use in restoration of major bone deficiencies. Prospective study on a case serie of 113 THA’s performed by two surgeons in a single institution. From 2000 to December 2003, 113 hips have undergone arthroplasty using porous tantalum implants consisting of 54 primary hip arthroplasties and 59 revision THA’s. The patients where evaluated clinical and radiographically every 3 month during the first year, and after yearly. Mean patient age was 64,2 years, (range 44–87); with 59% males and 41% females. No patients died or lost to follow-up. No further surgeries of the involved hip. No radiographic signs of loosening of the acetabular component according to the criteria of Hodgkinson et al. No problems specifically from the use of acetabular augments or extra screws has been noted. Of the revision series, a total of 16 cases have received acetabular augments. Complications included 1 superficial infection, 2 dislocations. No vasculo-nervous complication; and in 2 cases technical difficulties to achieve good fixation due to ethiology of the THA (desarthrodesis). The average Harris hip score improved from 48 to 89 following primary surgery. Tantalum acetabular components for primary and revision hip surgery have performed well for up to 3 years, and have excellent stability. The two-piece acetabular shell and augments permits the reconstruction of every acetabular bone defect

Introduction. Tantalum is a pure metallic element and is attractive for use in orthopaedic implants because it is one of the most biocompatible metals available for implant fabrication. The potential advantages for the use of porous tantalum in total hip arthroplasty include: 1) excellent bone and tissue ingrowth observed histologically; 2) direct polyethylene intrusion into the metal substrate. This allows the elimination of any potential backside wear in the monoblock cup; 3) The two-piece design consist of a tantalum shell with screw holes for fixation into the dome of the ilium and posterior column. A polyethylene liner is cemented into the tantalum shell to eliminates backside motion. In addition, acetabular augments of porous tantalum have been developed for use in restoration of major bone deficiencies. Prospective study on a case serie of 113 THA’s performed by two surgeons in a single institution. Material & Methods. From 2000 to December 2003, 113 hips have undergone arthroplasty using porous tantalum implants consisting of 54 primary hip arthroplasties and 59 revision THA’s. The patients where evaluated clinical and radiographically every 3 month during the first year, and after yearly. Mean patient age was 64,2 years, (range 44–87); with 59% males and 41% females. Results. No patients died or lost to follow-up. No further surgeries of the involved hip. No radiographic signs of loosening of the acetabular component according to the criteria of Hodgkinson et al. No problems specifically from the use of acetabular augments or extra screws has been noted. Of the revision series, a total of 16 cases have received acetabular augments. Complications included 1 superficial infection, 2 dislocations. No vasculo-nervous complication; and in 2 cases technical difficulties to achieve good fixation due to ethiology of the THA (desarthrodesis). The average Harris hip score improved from 48 to 89 following primary surgery. Discussion and Conclusions Tantalum acetabular components for primary and revision hip surgery have performed well for up to 3 years, and have excellent stability. The two-piece acetabular shell and augments permits the reconstruction of every acetabular bone defect

Acetabular bone loss is a challenging problem facing the revision total hip replacement surgeon. Reconstruction of the acetabulum depends on the presence of anterosuperior and posteroinferior pelvic column support for component fixation and stability. The Paprosky classification is most commonly used when determining the location and degree of acetabular bone loss. Augments serve the function of either providing primary construct stability or supplementary fixation. . When a pelvic discontinuity is encountered we advocate the use of an acetabular distraction technique with a jumbo cup and modular porous metal acetabular augments for the treatment of severe acetabular bone loss and associated chronic pelvic discontinuity. Cite this article: Bone Joint J 2014;96-B(11 Suppl A):36–42

The conventional method for reconstructing acetabular bone loss at revision surgery includes using structural bone allograft. The disadvantages of this technique promoted the advent of metallic but biocompatible porous implants to fill bone defects enhancing initial and long-term stability of the acetabular component. This paper presents the indications, surgical technique and the outcome of using porous metal acetabular augments for reconstructing acetabular defects. . Cite this article: Bone Joint J 2013;95-B, Supple A:103–8

There has been a longstanding need for a structural biomaterial that can serve as a bone graft substitute or implant construct and is effective for fixation by bone ingrowth. A porous tantalum material was developed to address these issues. The purpose of this paper and presnetation is to describe the properties and 2 to 5 year clinical results of porous tantalum in various reconstructive orthopaedic procedures. Porous tantalum has been used to manufacture primary and revision acetabular cups, acetabular augments, tibial and patella implants, patellar augments, structural devices for the treatment of osteonecrosis, and spinal fusion implants. Clinical follow-up includes: 2–5 year clinical and radiographic evaluation of: 414 monoblock cups in primary THA, 36 monoblock cups and 587 revision hemispheres used in revision THR, 16 hips revised with acetabular augments and revision hemispheres; 2 to 4 years for 101 tibial implants used in primary TKR and 69 patellas used in cementless TKR; 2–4 years for 11 patellar augments in salvage TKR, 1–5 years for 53 revision TKRs using knee spacers; 1–4 years for 91 osteone-crosis hip implants; and for 15 cervical fusion cases. This innovative tantalum implant material with trabecular architecture possesses advantages in stiffness, friction coefficient, porosity, rate and extent of tissue ingrowth, and versatility in manufacturing of structural devices. It has been clinically validated in numerous and diverse reconstructive procedures

The direct lateral (or anterolateral) approaches to the hip for revision THA involve detachment of the anterior aspect of the gluteus medius from the trochanter along with a contiguous sleeve of the vastus lateralis. Anterior retraction of this flap of gluteus medius and vastus lateralis and simultaneous posterior retraction of the femur creates an interval for division of gluteus minimus and deeper capsular tissues and exposure of the joint. To enhance reattachment of this flap of the anterior portion of the gluteus medius and vastus lateralis back to the trochanter, an oblique wafer of bone can be elevated along with the muscle off of the anterolateral portion of the trochanter. This bony wafer prevents suture pull out when large nonabsorbable sutures are used around or through the fragment and passed into the bone of the trochanteric bed for reattachment during closure. To prevent excessive splitting proximally into the gluteus medius muscle (and resulting damage to the superior gluteal nerve), it is often helpful to extend the muscle split further distally down into the vastus lateralis. This combined with careful elevation of the gluteal muscles off of the ilium (instead of splitting them) helps provide excellent and safe exposure of the entire rim of the acetabulum and access to the supracetabular region for bone grafting, acetabular augment placement and even fixation of the flanges of a cage. A simple method for posterior column plating via the anterolateral approach involves contouring of the distal end of the plate around the base of the ischium at the inferior edge of the socket. When an extended osteotomy of the femur is needed to correct deformity, remove a well-fixed implant or cement, the “extensile” variation of this same surgical approach involves a Wagner style (lateral to medial) osteotomy of the greater trochanter and proximal femur. The anterior portion of the femur after it is osteotomised is elevated as a separate segment while maintaining the soft tissue attachments to the bone as much as possible to aid osteotomy healing. After implant or cement removal, this approach gives excellent direct access to the distal femur for placement of a long stem revision femoral component without bone-implant conflict proximally because of the bow of the femur. The anterolateral approach (and extensile variants detailed above) can be used routinely and safely in the full range of revision THA procedures, or it can be employed selectively, if desired, in cases at increased risk for dislocation

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

The endoprosthetic treatment of secondary osteoarthritis resulting from congenital hip dysplasia is difficult due to the small diameter of the acetabulum and the hypoplastic anterolateral bone stock. On the femoral side the increased femoral anteversion, insufficient femoral offset and proximal femoral deformities (mostly valgus deformities) as well as the small diameter and straight form of the intramedullary canal pose challenges. Careful preoperative planning is mandatory. The Crowe classification is usually used to describe these pathologies. In severe cases (Crowe 3 and especially Crowe 4) a shortening and derotating femoral osteotomy should be taken into account. Small acetabular components, acetabular augments, and modular femoral components must be available at all times. For acetabular fixation press-fit cups are preferred today, but excellent results were also described for threaded cups. The advantage of press-fit cups is the extensively documented and superior track record, but threaded cups allow for an easier reconstruction of the original hip center as well as slight medialization. As a result of medialization a reduction in polyethylene wear together with a low rate of loosening lead to very good long-term results in a younger patient population. Cementless straight stems are documented to be preferable for the small femoral diameter and the straight anatomic shape of the proximal femur. Nevertheless, the higher complication rate, especially the increased rate of nerve palsies, should be preoperatively discussed with the patient. The ideal bearing surface is currently unclear, ceramic-on-ceramic seems to be promising, although the longest data available support the use of metal-on-polyethylene

The advent of modular porous metal augments has ushered in a new form of treatment for acetabular bone loss. The function of an augment can be seen as reducing the size of a defect or reconstituting the anterosuperior/posteroinferior columns and/or allowing supplementary fixation. Depending on the function of the augment, the surgeon can decide on the sequence of introduction of the hemispherical shell, before or after the augment. Augments should always, however, be used with cement to form a unit with the acetabular component. Given their versatility, augments also allow the use of a hemispherical shell in a position that restores the centre of rotation and biomechanics of the hip. Progressive shedding or the appearance of metal debris is a particular finding with augments and, with other radiological signs of failure, should be recognized on serial radiographs. Mid- to long-term outcomes in studies reporting the use of augments with hemispherical shells in revision total hip arthroplasty have shown rates of survival of > 90%. However, a higher risk of failure has been reported when augments have been used for patients with chronic pelvic discontinuity.

Cite this article: Bone Joint J 2024;106-B(4):312–318.

Aims

Nonagenarians (aged 90 to 99 years) have experienced the fastest percent decile population growth in the USA recently, with a consequent increase in the prevalence of nonagenarians living with joint arthroplasties. As such, the number of revision total hip arthroplasties (THAs) and total knee arthroplasties (TKAs) in nonagenarians is expected to increase. We aimed to determine the mortality rate, implant survivorship, and complications of nonagenarians undergoing aseptic revision THAs and revision TKAs.

Introduction. Acetabular revision for cavitary defects in failed total hip replacement remains a challenge for the orthopaedic surgeon. Bone graft with cemented or uncemented revision is the primary solution; however, there are cases where structural defects are too large. Cup cage constructs have been successful in treating these defects but they do have their problems with early loosening and metalwork failure. Recently, highly porous cups that incorporate metal augments have been developed to achieve greater intra-operative stability showing encouraging results. Methods. Retrospective analysis of twenty-six consecutive acetabular revisions with Trabecular Titanium cups. Inclusion criteria included aseptic cases, adult patients, end-stage disease with signs of loosening, no trauma nor peri-prosthetic fractures. Data was obtained for patient demographics, Paprosky classification, use of bone graft, use of acetabular augment, and Moore index of osseointegration. Results. Twenty-six subjects were included in the study. Four patients were lost to follow up due to death. The average age was 73 (range 50–91) with 16 females and 10 males. The Paprosky classification was as follows: type I=7 (26.9%), type IIa=7 (26.9%), type IIb=4 (15.4%), type IIc=2 (7.7%), type IIIa=6 (23%). The Moore index at 6 months was as follows: type I=2 (7.7%), type II=4 (15.4%), type III=8 (30.1%), type IV= 6 (23%), type V=3 (11.5%), no data =3 (11.5). At 12 months: type I=0, type II=2 (7.7%), type III=5 (19.2%), type IV=7 (26.9%), type V=4 (15.4%), no data = 8 (4 no radiographs and 4 deceased). Augments were used in 8 patients. All cups implanted had supplemented screw fixation. Discussion. Revision acetabular surgery for aseptic loosening remains a challenge, particularly with cavitary defects. Success of surgery depends on solid fixation at the time of implantation and good, rapid osseointegration. With cavitary defects, stability of the implant becomes an issue, needing implants capable of filling the defects, with good porosity and enough surface roughness to achieve early stability. We found the Trabecular Titanium cup to have very high porosity and surface roughness allowing very good and stable fixation. The use of augments did not affect the initial stability of the implant. The Moore index of osseointegration reliably detects bony ingrowth of the cup of radiographic analysis by assessing (1) absence of radiolucent lines; (2) presence of a superolateral buttress; (3) medial stress-shielding; (4) radial trabeculae; and (5) an inferomedial buttress. Each sign had a high PPV for the presence of bone ingrowth. Ninety-seven percent of cups with three to five signs were ingrown, whereas 83% of cups with one or no signs were unstable. With three or more signs present, the PPV was 96.9%, the sensitivity was 89.6%, and specificity was 76.9%. In our study, 61.5% of patients had 3 signs or more and 69.2% of patients had 2 signs or more at 12 months. Conclusion. The Trabecular Titanium. TM. cup demonstrates good initial stability at implantation, and at twelve-months excellent osseointegration. These results are comparable to published results for similar trabecular cup designs. Further long-term studies are welcome and we continue to monitor this group of patients

We present the results of 228 consecutive Charnley low friction arthroplasties, inserted in 193 patients between July 1972 and December 1976. All hips were inserted by the posterior approach without trochanteric osteotomy. All patients were enrolled into a prospective study and pre-and post-operative findings recorded. This series was reviewed in 1985 and once again in 2002. The pre-and peri-operative findings are similar to contemporary series. Due to our stable population only two patients were lost to follow-up. Our survivorship results show a 10-year survival of 93%, 20-year survivorship of 84% deteriorating to a 30-year survival of 73%. Of the 26 hips revised 6 were for recurrent dislocations and these were satisfactorily stabilised using acetabular augments. There were 8 revisions for fracture of the femoral component (all flatbacks), 8 revisions for aseptic loosening of the femoral component and 6 revisions for aseptic loosening of the acetabulum. There was one revision for deep infection and the remaining 3 were for periprosthetic fractures. The survivors were scored clinically using the Merle d’Aubign-Postel score with a mean value of 12. None of the survivors were on the waiting list for revision arthroplasty or felt that it was indicated. Overall our results are comparable to other studies and vindicate the choice of approach, which at the time was a source of some controversy

Recurrent posterior dislocation is a recognised complication following primary total hip arthroplasty. Incidences of between 0.11% and 4.5% have been reported in the literature. Component revision is regarded as standard management of recurrent posterior dislocation. However, revision surgery is a major surgical procedure and is often unsuitable for elderly, frail patients. A congruent, ultra-high molecular weight polyethylene acetabular augment with a stainless steel backing plate has been developed. This can be inserted providing there is no malalignment, wear or loosening of the primary components. In this study we compared twenty patients who underwent conventional revision surgery to twenty patients who had a PLAD inserted for recurrent posterior dislocation following primary Charnley total hip arthroplasty. Both groups were age and sex-matched and the average number of dislocations prior to surgery was three for each group. For the PLAD group, the mean operative time, the mean intraoperative blood loss, the time spent in HDU, the transfusion requirements and the duration of hospital stay was significantly less than that for the revision group. Furthermore, there was no significant difference in the Oxford Hip Score recorded preoperatively and at 6 weeks, 6 months, one year and two years following surgery. None of the patients had sustained a further dislocation at latest review. We conclude that the Posterior Lip Augmentation Device is a safe and effective option in the management of patients with recurrent posterior hip dislocation when there is no evidence of component failure or gross malposition