Aims. The stability of cementless acetabular components is an important factor for surgical planning in the treatment of patients with pelvic osteolysis after total hip arthroplasty (THA). However, the methods for determining the stability of the acetabular component from pre-operative radiographs remain controversial. Our aim was to develop a scoring system to help in the assessment of the stability of the acetabular component under these circumstances. Patients and Methods. The new scoring system is based on the mechanism of failure of these components and the location of the osteolytic lesion, according to the DeLee and Charnley classification. Each zone is evaluated and scored separately. The sum of the individual scores from the three zones is reported as a total score with a maximum of 10 points. The study involved 96 revision procedures which were undertaken for wear or osteolysis in 91 patients between July 2002 and December 2012. Pre-operative anteroposterior pelvic radiographs and Judet views were reviewed. The stability of the acetabular component was confirmed intra-operatively. Results. Intra-operatively, it was found that 64 components were well-fixed and 32 were loose. Mean total scores in the well-fixed and loose components were 2.9 (0 to 7) and 7.2 (1 to 10), respectively (p < 0.001). In hips with a low score (0 to 2), the component was only loose in one of 33 hips (3%). The incidence of loosening increased with increasing scores: in those with scores of 3 and 4, two of 19 components (10.5%) were loose; in hips with scores of 5 and 6, eight of 19 components (44.5%) were loose; in hips with scores of 7 or 8, 13 of 17 components (70.6%) were loose; and for hips with scores of 9 and 10, nine of nine components (100%) were loose. Receiver-operating-characteristic curve analysis demonstrated very good accuracy (area under the curve = 0.90, p < 0.001). The optimal cutoff point was a score of ≥ 5 with a sensitivity of 0.79, and a specificity of 0.87. Conclusion. There was a strong correlation between the scoring system and the probability of loosening of a cementless acetabular component. This scoring system provides a clinically useful tool for pre-operative planning, and the evaluation of the outcome of revision surgery for patients with loosening of a cementless acetabular component in the presence of osteolysis. Cite this article: Bone Joint J 2017;99-B:601–6

We reviewed the long-term results at ten to 12 years of 118 total hip replacements in 109 patients using a second-generation hemispherical cementless acetabular component (Reflection) designed to address the problem of backside wear. Five patients (five hips) died and six patients (seven hips) were lost to follow-up. The remaining 98 patients (106 hips) had a mean age of 62.9 years (34.0 to 86.2) A rate of revision for aseptic loosening of 0.9%, and predictable results were found with respect to radiological evidence of fixation, lack of pain, walking ability, range of movement and function. One component was revised for aseptic loosening, and of the 101 hips (95.2%) that did not have a revision, minor osteolytic lesions of the pelvis were seen in six (5.9%). Kaplan-Meier survival analysis for the total cohort of 118 hips revealed a 96.4% survival at both ten (95% confidence interval 90 to 98) and 12 years (95% confidence interval 86 to 98)

Four hundred and fifteen patients with cementless acetabular components of either a smooth threaded (130) or porous surfaced (285) variety were compared for clinical symptoms and radiographic signs of component loosening. At a mean 4.8 year follow-up none of the patients with porous acetabular components had signs of component instability. At a mean 3.9 year follow-up 27 (21%) of the patients with a smooth threaded acetabular component showed radiographic signs of instability and 33 (25%) had clinical symptoms. The disappointing short-term results with these threaded cups in our hands have prompted us to abandon their use in favour of the porous surfaced hemispherical cups

Removal of well-fixed, cementless, acetabular components during revision arthroplasty remains a challenging problem. Further damage to host bone may limit options for reconstruction and compromise the long-term result of the revision operation. We report the results of 31 hips with well-fixed, cementless sockets which were removed using a new cup extraction system. In all hips the socket was removed without difficulty and with minimal further bone loss

Introduction and Aims: We undertook this study to detemine the results of acetabular fixation using the Duraloc 300 uncemented acetabular component in patients with inflammatory joint disease and poor bone stock. Method: Fifty consecutive total hip replacements using a Duraloc 300 cup in patients with imflammatory joint disease were reviewed at an average of 8.2 years. Postoperative x-rays were analysed for cup placement and interface gaps. Follow-up films were analysed for lucent lines, osteolysis, wear and migration. Kaplan-Meier survivorship analysis was performed. Results: All components were found to be stable with no evidence of loosening or migration. One patient developed sepsis seven years post-surgery. There was no evidence of excessive wear or osteolysis. Conclusion: The Duraloc 300 cementless acetabular component has excellent fixation with no cases of loosening at an average of 8.2 years in patients with inflammatory joint disease. The low rate of wear and pelvic osteolysis may be indicative of the decreased demands placed on the prosthesis in this cohort of patients. The poor bone stock has not however adversely effected acetabular fixation

The membranes surrounding seven loose cementless acetabular implants were shown to contain polyethylene particles, birefringent in polarised light. Three of these implants were made of titanium alloy and the membranes around these contained titanium particles as well. There was no metallosis around the four implants made of chromium-cobalt-steel alloy. Both titanium and polyethylene particles caused migration, adherence and phagocytosis of CD11b-positive, peroxidase-negative macrophages. There were no histological signs of activation of the specific immune response; neither interleukin-2 receptor-positive activated T cells nor PCA-1 plasmablasts/plasma cells were present in the tissues. In cases of simple loosening, resident mesenchymal fibroblast-like cells were active. In aggressive granulomatosis, there were many macrophages and multinucleated giant cells but little fibroblast reaction. The clinical relevance of the findings is that the use of cementless prostheses is not a guarantee against adverse tissue reactions.

Cementless acetabular fixation has demonstrated superior long-term durability in total hip replacement, but most series have studied implants with porous metal surfaces. We retrospectively evaluated the results of 100 consecutive patients undergoing total hip replacement where a non-porous Allofit component was used for primary press-fit fixation.

This implant is titanium alloy, grit-blasted, with a macrostructure of forged teeth and has a biradial shape. A total of 81 patients (82 hips) were evaluated at final follow-up at a mean of 10.1 years (8.9 to 11.9). The Harris Hip Score improved from a mean 53 points (23 to 73) pre-operatively to a mean of 96 points (78 to 100) at final review. The osseointegration of all acetabular components was radiologically evaluated with no evidence of loosening. The survival rate with revision of the component as the endpoint was 97.5% (95% confidence interval 94 to 100) after 11.9 years. Radiolucency was found in one DeLee-Charnley zone in four acetabular components. None of the implants required revision for aseptic loosening. Two patients were treated for infection, one requiring a two-stage revision of the implant. One femoral stem was revised for osteolysis due to the production of metal wear debris, but the acetabular shell did not require revision.

This study demonstrates that a non-porous titanium acetabular component with adjunct surface fixation offers an alternative to standard porous-coated implants.

Summary Sentence: Cementless solid tri-spiked titanium shells, with a polished inner surface and improved locking mechanism, demonstrated excellent fixation and survivorship at mid-term (minimum 5 years) follow-up.

Introduction: The tri-spiked Reflection cup (Smith & Nephew, Memphis) is a second-generation solid titanium shell with a polished inner surface, no screw holes and an improved locking mechanism. The purpose of this prospective study was to evaluate the minimum 5-year clinical & radiographic results and survivorship of this second-generation acetabular component.

Methods: Between 1997 and 2003, 659 primary THA were performed using the Reflection tri-spiked socket. None of the shells had adjuvant fixation with screws. The mean follow-up time was 7.0 years (5 to 11 yrs). The patients were followed prospectively using validated clinical outcome scores (WOMAC, SF-12, Harris Hip scores) and yearly radiographs.

Results: Twenty-seven patients had died before the minimum 5-year follow-up period. The mean Harris Hip and WOMAC scores were 89 and 79 respectively at last follow-up. Three sockets (0.6%) had been revised: two for infection, one for component malpositioning. No cup was revised for aseptic loosening. Six liners were exchanged: three for residual instability, 3 for wear associated with aseptic loosening of the stem. Radiographic review of remaining cups in-situ identified no cases of loosening and only a small number of cups (< 3%) with any osteolysis. The KM survivorship analysis with revision for any reason, was 97.5% and 97.4% at 5 and 10 years, while survivorship of the acetabular component was 99.8% at 5 and 10 years.

Conclusions: This second-generation cementless solid tri-spiked titanium shell, with a polished inner surface and improved locking mechanism, demonstrated excellent fixation and survivorship at mid-term follow-up.

Introduction and Aims: We undertook this study to detemine the results of acetabular fixation using the Duraloc 300 uncemented acetabular component combined with impaction bone grafting in patients with acetabular protrusion.

Method: Thirty consecutive total hip replacements using a Duraloc 300 cup in patients with acetabular protrusion requiring impaction bone grafting were reviewed at an average of 5.2 years. Pre-operative x-rays were analysed for degree of protrusion. Post-operative x-rays were analysed for cup placement and interface gaps. Follow-up films were analysed for graft incorporation, lucent lines, osteolysis, wear and migration. Kaplan-Meier survivorship analysis was performed.

Results: All components were found to be stable with no evidence of loosening or migration. All but two cases showed trabeculated bone with an average minimum thickness of 7mm of bone medial to the cup in zone 2. Mean rate of wear was 0.10mm per year. No cases of pelvic osteolysis were seen.

Conclusion: The Duraloc 300 cup provides excellent fixation in patients with acetabular protrusion and impaction bone grafting. The graft has been found to incorporate and remodel. We are therefore optimistic that the durability of fixation should equal that of primary hip surgery without protrusion.

We performed 114 consecutive primary total hip arthroplasties with a cementless expansion acetabular component in 101 patients for advanced osteonecrosis of the femoral head. The mean age of the patients at surgery was 51 years (36 to 62) and the mean length of follow-up was 110 months (84 to 129). The mean pre-operative Harris hip score of 47 points improved to 93 points at final follow-up. The polyethylene liner was exchanged in two hips during this period and one broken acetabular component was revised. The mean linear wear rate of polyethylene was 0.07 mm/year and peri-acetabular osteolysis was seen in two hips (1.9%). Kaplan-Meier analysis indicated that the survival of the acetabular component without revision was 97.8% (95% confidence interval 0.956 to 1.000) at ten years. Our study has shown that the results of THA with a cementless expansion acetabular component and an alumina-polyethylene bearing surface are good

Adult human cadaver pelves were tested to determine micromotion at the prosthesis-bone interface in cementless hemispherical acetabular components during simulated single-limb stance. The micromotion of non-press-fit components with screw fixation in response to cyclic loads to a maximum of 1500N was compressive (interface closing) at the superior iliac rim and distractive (interface opening) at the inferior ischial rim; that of press-fit components was compressive all around the acetabular rim regardless of screw fixation. Adding screws to the component decreased the micromotion at the site of the screw, but sometimes increased it at the opposite side. Two dome screws with the press-fit component decreased the micromotion at the superior iliac rim but at the inferior ischial rim there was either no change or increased movement. A press-fit cup shows less micromotion than a non-press-fit cup with screw fixation. The addition of screws to a press-fit cup does not necessarily increase the initial stability

We report the use of a 15° face-changing cementless acetabular component in patients undergoing total hip replacement for osteoarthritis secondary to developmental dysplasia of the hip. The rationale behind its design and the surgical technique used for its implantation are described. It is distinctly different from a standard cementless hemispherical component as it is designed to position the bearing surface at the optimal angle of inclination, that is, < 45°, while maximising the cover of the component by host bone.

We have evaluated the results of total hip replacement in patients with congenital hip disease using 46 cemented all-polyethylene Charnley acetabular components implanted with the cotyloplasty technique in 34 patients (group A), and compared them with 47 metal-backed cementless acetabular components implanted without bone grafting in 33 patients (group B). Patients in group A were treated between 1988 and 1993 and those in group B between 1990 and 1995. The mean follow-up for group A was 16.6 years (12 to 18) and the mean follow-up for group B was 13.4 years (10 to 16). Revision for aseptic loosening was undertaken in 15 hips (32.6%) in group A and in four hips (8.5%) in group B. When liner exchange was included, a total of 13 hips were revised in group B (27.7%). The mean polyethylene wear was 0.11 mm/yr (0.002 to 0.43) and 0.107 mm/yr (0 to 0.62) for groups A and B, respectively. Polyethylene wear in group A was associated with linear osteolysis, and in group B with expansile osteolysis. In patients with congenital hip disease, when 80% cover of the implant can be obtained, a cementless acetabular component appears to be acceptable and provides durable fixation. However, because of the type of osteolysis arising with these devices, early exchange of a worn liner is recommended before extensive bone loss makes revision surgery more complicated

Eighty-three patients (ninety hips) with well-fixed cementless socket retained during revision of a femoral component were reviewed. At revision, 33% of patients had acetabular osteolysis and 52% were grafted. At mean follow-up 9.6 years (5.5 – 15.9) after femoral revision and 14.8 years (7.1–20.2) after primary arthroplasty, survivorship was 96.5% (95% CI, 91.5% to 100%) at five years and 81%(95% CI, 61% to 99%) at ten years after femoral revision. Revision of a cementless acetabular component solely on the basis of the duration that it was in vivo or whether a previous revision had been done does not appear to be warranted. Removal a well fixed cementless acetabular component can result in an increased operative morbidity. Data that can be used to predict the long-term survival of retained well-fixed cementless acetabular components are therefore needed. Retention of the well-fixed cementless acetabular component during femoral revision is a predictable technique. Revision of a cementless acetabular component solely on the basis of the duration that it was in vivo or whether a previous revision had been done does not appear to be warranted. Eighty-three consecutive patients (ninety hips) in whom a well-fixed cementless socket had been retained during revision of a femoral component were reviewed. Mean patient age was fifty-four. At the time of revision, 33% of the patients had acetabular osteolysis of which 52% were grafted. At a mean follow-up 9.6 years (5.5 – 15.9) after femoral revision and 14.8 years (7.1–20.2) after primary arthroplasty, 94.5% of the sockets remained in place. With any revision as end point, survivorship was 96.5%(95% CI, 91.5% to 100%) at five years and 81%(95% CI, 61% to 99%) at ten years after femoral revision. With failure of cementless socket as end point (i.e. loosening, deficient locking mechanism), survivorship was 100% (95% CI, 100%) and 94% (95% CI, 82%–100%) at five and ten years after femoral revision and 100% (95% CI, 100%) and 94% (95% CI, 82%–100%) at ten and fifteen years after primary arthroplasty. No cases showed recurrence or expansion of pelvic osteolysis. The overall incidence of dislocation was 15%

We performed 52 total hip replacements in 52 patients using a cementless acetabular component combined with a circumferential osteotomy of the medial acetabular wall for the late sequelae of childhood septic arthritis of the hip. The mean age of the patients at operation was 44.5 years (22 to 66) and the mean follow-up was 7.8 years (5 to 11.8). The mean improvement in the Harris Hip Score was 29.6 points (19 to 51) at final follow-up. The mean cover of the acetabular component was 98.5% (87.8% to 100%). The medial acetabular wall was preserved with a mean thickness of 8.3 mm (1.7 to 17.4) and the mean length of abductor lever arm increased from 43.4 mm (19.1 to 62) to 54.2 mm (36.5 to 68.6). One acetabular component was revised for loosening and osteolysis 4.5 years postoperatively, and one had radiolucent lines in all acetabular zones at final review. Kaplan-Meier survival was 94.2% (95% confidence interval 85.8% to 100%) at 7.3 years, with revision or radiological loosening as an end-point when two hips were at risk. A cementless acetabular component combined with circumferential medial acetabular wall osteotomy provides favourable results for acetabular reconstruction in patients who present with late sequelae of childhood septic hip arthritis

The last two decades have seen remarkable technological advances in total hip arthroplasty (THA) implant design. Porous ingrowth surfaces and highly crosslinked polyethylene (HXLPE) have been expected to dramatically improve implant survivorship. The purpose of the present study was to evaluate survival of contemporary cementless acetabular components following primary THA. 16,421 primary THAs performed for osteoarthritis between 2000 and 2019 were identified from our institutional total joint registry. Patients received one of 12 contemporary cementless acetabular designs with HXLPE liners. Components were grouped based on ingrowth surface into 4 categories: porous titanium (n=10,952, mean follow-up 5 years), porous tantalum (n=1223, mean follow-up 5 years), metal mesh (n=2680, mean follow-up 6.5 years), and hydroxyapatite (HA) coated (n=1566, mean follow-up 2.4 years). Kaplan-Meier analyses were performed to assess the survivorship free of acetabular revision. A historical series of 182 Harris-Galante-1 (HG-1) acetabular components was used as reference. The 15-year survivorship free of acetabular revision was >97% for all 4 contemporary cohorts. Compared to historical control, porous titanium (HR 0.06, 95% CI 0.02–0.17, p<0.001), porous tantalum (HR 0.09, 95%CI 0.03–0.29, p<0.001), metal mesh (HR 0.11, 95%CI 0.04–0.31, p<0.001), and HA-coated (HR 0.14, 95%CI 0.04–0.48, p=0.002) ingrowth surfaces had significantly lower risk of any acetabular revision. There were 16 cases (0.1%) of acetabular aseptic loosening that occurred in 8 (0.07%) porous titanium, 5 (0.2%) metal mesh, and 3 (0.2%) HA-coated acetabular components. 7 of the 8 porous titanium aseptic loosening cases occurred in one known problematic design. There were no cases of aseptic loosening in the porous tantalum group. Modern acetabular ingrowth surfaces and HXLPE liners have improved on historical results at the mid-term. Contemporary designs have extraordinarily high revision-free survivorship, and aseptic loosening is now a rare complication. At mid-term follow-up, survivorship of contemporary uncemented acetabular components is excellent and aseptic loosening occurs in a very small minority of patients

Background. We have often experienced a change of the tone of the hammering sound during the press-fit implantation of cementless acetabular components in total hip arthroplasty (THA). The tone of the impact sound before the press-fit of acetabular components seems to differ from the tone after the press-fit. This change of tone may depend on the accuracy of the fit of the acetabular component, or it may simply be a subjective perception. The aim of this study is to evaluate the impact sounds in the press-fit implantation of cementless acetabular components. Methods. The hammering sounds in press-fit implantation of acetabular components were studied intraoperatively in 22 patients (28 hips) who underwent primary THA for treatment of advanced osteoarthritis. All operations were performed via the direct anterior approach in a supine position. The hemispherical titanium-alloy acetabular component (TriAD; stryker) was implanted in all patients. A sound level meter (NA-28; RION) was used to record and analyze the sounds. The hammering sounds of the first three hits and last three hits were recorded as the “before press-fit” and “after press-fit” sound samples, respectively. A frequency analysis was then performed at the point of peak sound pressure in each sample. Results. The dominant frequency of the impact sounds was equal to or lower than 1 kHz in 20% of the before press-fit samples and 76% of the after press-fit samples, and equal to or higher than 4 kHz in 69% of the before press-fit samples and 21% of the after press-fit samples. The frequency of the impact sounds changed significantly (p<0.01) during the press-fit implantation. Conclusion. The frequency of the impact sound changed significantly during the press-fit implantation of cementless acetabular components. We conclude that an intraoperative evaluation of the impact sound might help to improve accuracy when implanting the acetabular component

The cemented acetabular component has been essentially abandoned, due to the reliable and durable fixation provided by bone ingrowth into cementless acetabular components of many different designs. A variety of porous surfaces including sintered beads, titanium fibermetal, plasma sprayed titanium, and ultraporous tantalum have been shown to result in significant osteointegration, and provide long term fixation of cementless acetabular components. New ultraporous metals will also likely prove to perform similarly, however, their advantages in the primary THA are unclear. Most currently available cementless acetabular components rely on obtaining initial “interference” or “frictional” fit provided by relative underreaming. Many designs incorporate additional features such as screws, pegs, and fins to limit implant micromotion and augment initial fixation until early tissue ingrowth occurs. “Underreaming” by more than 1 mm has been associated with incomplete component seating and increased incidence of acetabular fracture. Knowledge of the geometry of the component by the surgeon is recommended, since some designs are elliptical and have a built-in degree of interference fit. Screws used to augment acetabular fixation in the primary THA can typically be restricted to the area of the acetabular dome (cluster configuration) and cups with multiple holes are usually unnecessary and may be undesirable as they allow access of wear debris to the acetabular implant-bone interface. In order to minimize backside wear and dissociation of the acetabular liner, modular components need to have a well-designed locking mechanism. Retrieval studies have shown that the peripheral rim of the acetabular liner is most susceptible to oxidative degradation and the integrity of the locking mechanism in this area can be compromised with time. Non-modular, “one piece” components eliminate these concerns, but most of these designs rely on initial frictional fit alone for stability. In the event that the position of a nonmodular component needs to be changed intra-operatively, the quality of frictional fit after repositioning can be diminished and may not be sufficient for implant stability. Modular components that incorporate screws, allow for acetabular component repositioning and adjunctive fixation with screws. Many newer acetabular component designs can accommodate a modular liner for either a metal on polyethylene, ceramic on ceramic or metal on metal bearing

Recent advancements in biomaterial technology have created novel options for acetabular fixation in primary total hip arthroplasty (THA). For example, cementless acetabular fixation has become the preferred option, however, there is continued debate concerning whether long-term survivorship is comparable to that of cemented component fixation. Many doubts previously associated with early cementless designs have been addressed with newer features such as improved locking mechanisms, enhanced congruity between the acetabular liner and the shell, and the inclusion of highly cross-linked ultra-high molecular weight polyethylene (UHMWPE). Additionally, there has been increased utilization of new porous metals, titanium mesh, and hydroxyapatite (HA) coated implants. However, several retrieval studies have indicated that porous-coated cementless acetabular components can exhibit poor bony ingrowth. Many surgeons in Europe favor cemented fixation, where registry data is favorable for this interface. A surgeon's decision to use a cemented or cementless acetabular component is typically dependent on factors such as patient bone stock, surgical training, and experience. With the frequency of THAs expected to increase, it is particularly important for orthopaedic surgeons to be familiar with appropriate preoperative planning and component selection in an effort to achieve optimal outcomes. Therefore, this talk will outline and describe the options currently available for cementless and cemented acetabular fixation in primary total hip arthroplasty

Aims. This study aimed to determine the diagnostic performance of radiographic criteria to detect aseptic acetabular loosening after revision total hip arthroplasty (THA). Secondary aims were to determine the predictive values of different thresholds of migration and to determine the predictive values of radiolucency criteria. Patients and Methods. Acetabular component migration to re-revision was measured retrospectively using Ein-Bild-Rontgen-Analyse (EBRA-Cup) and manual measurements (Sutherland method) in two groups: Group A, 52 components (48 patients) found not loose at re-revision and Group B, 42 components (36 patients) found loose at re-revision between 1980 and 2015. The presence and extent of radiolucent lines was also assessed. Results. Using EBRA, both proximal translation and sagittal rotation were excellent diagnostic tests for detecting aseptic loosening. The area under the receiver operating characteristic (ROC) curves was 0.94 and 0.93, respectively. The thresholds of 2.5 mm proximal translation or 2° sagittal rotation (EBRA) in combination with radiolucency criteria had a sensitivity of 93% and specificity of 88% to detect aseptic loosening. The sensitivity, specificity, positive predictive value and negative predictive value (NPV) of radiolucency criteria were 41%, 100%, 100% and 68% respectively. Manual measurements of both proximal translation and sagittal rotation were very good diagnostic tests. The area under the ROC curve was 0.86 and 0.92 respectively. However, manual measurements had a decreased specificity compared with EBRA. Radiolucency criteria had a poor sensitivity and NPV of 41% and 68% respectively. Conclusion. This study shows that EBRA and manual migration measurements can be used as accurate diagnostic tools to detect aseptic loosening of cementless acetabular components used at revision THA. Radiolucency criteria should not be used in isolation to exclude loosening of cementless acetabular components used at revision THA given their poor sensitivity and NPV. Cite this article: Bone Joint J 2017;99-B:458–64