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)

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

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.

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

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

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

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

Aims. The purpose of this study was to determine the sensitivity, specificity and predictive values of previously reported thresholds of proximal translation and sagittal rotation of cementless acetabular components used for revision total hip arthroplasty (THA) at various times during early follow-up. Patients and Methods. Migration of cementless acetabular components was measured retrospectively in 84 patients (94 components) using Ein-Bild-Rontgen-Analyse (EBRA-Cup) in two groups of patients. In Group A, components were recorded as not being loose intra-operatively at re-revision THA (52 components/48 patients) and Group B components were recorded to be loose at re-revision (42 components/36 patients). Results. The mean proximal translation and sagittal rotation were significantly higher in Group B than in Group A from three months onwards (p < 0.02). Proximal translation > 1.0 mm within 24 months had a positive predictive value (PPV) of 90% and a specificity of 94%, but a sensitivity of 64%. Proximal translation > 1.0 mm within the first 24 months correctly identified 76 of 94 (81%) of components to be either loose or not loose. However, ten components in Group B (24%) did not migrate proximally above 1.0 mm within the first 60 months. Conclusion. The high PPV of EBRA-Cup measurements of proximal translation (90%) shows that this can be used in early follow-up to identify patients at risk of aseptic loosening. The absence of proximal translation within the first 60 months indicates a component is not likely to be loose at re-revision THA although it does not exclude late aseptic loosening as a cause of failure. Cite this article: Bone Joint J 2017;99-B:465–74

Aims. The aim of this study was to determine the stability of a new short femoral stem compared with a conventional femoral stem in patients undergoing cementless total hip arthroplasty (THA), in a prospective randomized controlled trial using radiostereometric analysis (RSA). Patients and Methods. A total of 53 patients were randomized to receive cementless THA with either a short femoral stem (MiniHip, 26 patients, mean age: 52 years, nine male) or a conventional length femoral stem (MetaFix, 23 patients, mean age: 53 years, 11 male). All patients received the same cementless acetabular component. Two-year follow-up was available on 38 patients. Stability was assessed through migration and dynamically inducible micromotion. Radiographs for RSA were taken postoperatively and at three, six, 12, 18, and 24 months. Results. At two years, there was significantly less subsidence (inferior migration) of the short femoral stem (head, 0.26 mm, 95% confidence interval (CI) 0.08 to 0.43, . sd. 0.38; tip, 0.11 mm, 95% CI -0.08 to 0.31, . sd. 0.42) compared with the conventional stem (head, 0.62 mm, 95% CI 0.34 to 0.90, . sd. 0.56, p = 0.02; tip, 0.43 mm, 95% CI 0.21 to 0.65, . sd. 0.44, p = 0.03). There was no significant difference in dynamically inducible micromotion, rate of complications or functional outcome. Conclusion. This study demonstrates that the short femoral stem has a stable and predictable migration. However, longer-term survival analysis still needs to be determined. Cite this article: Bone Joint J 2018;100-B:1148–56

Aims. Cementless acetabular components rely on press-fit fixation for initial stability. In certain cases, initial stability is more difficult to obtain (such as during revision). No current study evaluates how a surgeon’s impaction technique (mallet mass, mallet velocity, and number of strikes) may affect component fixation. This study seeks to answer the following research questions: 1) how does impaction technique affect a) bone strain generation and deterioration (and hence implant stability) and b) seating in different density bones?; and 2) can an impaction technique be recommended to minimize risk of implant loosening while ensuring seating of the acetabular component?. Methods. A custom drop tower was used to simulate surgical strikes seating acetabular components into synthetic bone. Strike velocity and drop mass were varied. Synthetic bone strain was measured using strain gauges and stability was assessed via push-out tests. Polar gap was measured using optical trackers. Results. A phenomenon of strain deterioration was identified if an excessive number of strikes was used to seat a component. This effect was most pronounced in low-density bone at high strike velocities. Polar gap was reduced with increasing strike mass and velocity. Conclusion. A high mallet mass with low strike velocity resulted in satisfactory implant stability and polar gap, while minimizing the risk of losing stability due to over-striking. Extreme caution not to over-strike must be exercised when using high velocity strikes in low-density bone for any mallet mass. Cite this article: Bone Joint Res 2020;9(7):386–393

A number of studies have reported satisfactory results from the isolated revision of an acetabular component. However, many of these studies reported only the short- to intermediate-term results of heterogeneous bearing surfaces in a mixed age group. We present our experience of using a ceramic-on-ceramic (CoC) bearing for isolated revision of an uncemented acetabular component in 166 patients (187 hips) who were under the age of 50 years at the time of revision. There were 78 men and 88 women with a mean age of 47.4 years (28 to 49). The most common reason for revision was polyethylene wear and acetabular osteolysis in 123 hips (66%), followed by aseptic loosening in 49 hips (26%). . We report the clinical and radiological outcome, complication rate, and survivorship of this group. The mean duration of follow-up was 15.6 years (11 to 19). . The mean pre-operative Harris hip score was 33 points (1 to 58), and improved to a mean of 88 points (51 to 100) at follow-up. The mean pre-operative total Western Ontario and McMaster Universities Osteoarthritis Index score was 63.2 (43 to 91) and improved to 19.8 points (9 to 61) post-operatively. Overall, 153 of 166 patients (92%) were satisfied with their outcome. Kaplan–Meier survivorship analysis, with revision or radiological evidence of implant failure (13 patients, 8%) as end-points, was 92% at 15 years (95% confidence interval 0.89 to 0.97). . Isolated revision of a cementless acetabular component using a CoC bearing gives good results in patients under 50 years of age. Cite this article: Bone Joint J 2015;97-B:1197–1203

Most published randomised controlled trials which compare the rates of wear of conventional and cross-linked (XL) polyethylene (PE) in total hip arthroplasty (THA) have described their use with a cementless acetabular component. . We conducted a prospective randomised study to assess the rates of penetration of two distinct types of PE in otherwise identical cemented all-PE acetabular components. . A total of 100 consecutive patients for THA were randomised to receive an acetabular component which had been either highly XL then remelted or moderately XL then annealed. . After a minimum of eight years follow-up, 38 hips in the XL group and 30 hips in the annealed group had complete data (mean follow-up of 9.1 years (7.6 to 10.7) and 8.7 years (7.2 to 10.2), respectively). In the XL group, the steady state rate of penetration from one year onwards was -0.0002 mm/year (. sd. 0.108): in the annealed group it was 0.1382 mm/year (. sd. 0.129) (Mann–Whitney U test, p < 0.001). No complication specific to either material was recorded. These results show that the yearly linear rate of femoral head penetration can be significantly reduced by using a highly XLPE cemented acetabular component. Cite this article: Bone Joint J 2015;97-B:1458–62

Aims. Radiostereometric analysis (RSA) studies of vitamin E-doped, highly crosslinked polyethylene (VEPE) liners show low head penetration rates in cementless acetabular components. There is, however, currently no data on cemented VEPE acetabular components in total hip arthroplasty (THA). The aim of this study was to evaluate the safety of a new cemented VEPE component, compared with a conventional polyethylene (PE) component regarding migration, head penetration, and clinical results. Patients and Methods. We enrolled 42 patients (21 male, 21 female) with osteoarthritis and a mean age of 67 years (. sd. 5), in a double-blinded, noninferiority, randomized controlled trial. The subjects were randomized in a 1:1 ratio to receive a reverse hybrid THA with a cemented component of either argon-gas gamma-sterilized PE component (controls) or VEPE, with identical geometry. The primary endpoint was proximal implant migration of the component at two years postoperatively measured with RSA. Secondary endpoints included total migration of the component, penetration of the femoral head into the component, and patient-reported outcome measurements. Results. In total, 19 control implants and 18 implants in the VEPE group were analyzed for the primary endpoint. We found a continuous proximal migration of the component in the VEPE group that was significantly higher with a difference at two years of a mean 0.21 mm (95% confidence interval (CI) 0.05 to 0.37; p = 0.013). The total migration was also significantly higher in the VEPE group, but femoral head penetration was lower. We found no difference in clinical outcomes between the groups. Conclusion. At two years, this cemented VEPE component, although having a low head penetration and excellent clinical results, failed to meet noninferiority compared with the conventional implant by a proximal migration above the proposed safety threshold of RSA. The early proximal migration pattern of the VEPE component is a reason for continued monitoring, although a specific threshold for proximal migration and risk for later failure cannot be defined and needs further study. Cite this article: Bone Joint J 2019;101-B:1192–1198

We describe the clinical and radiological results of cementless primary total hip replacement (THR) in 25 patients (18 women and seven men; 30 THRs) with severe developmental dysplasia of the hip (DDH). Their mean age at surgery was 47 years (23 to 89). In all, 21 hips had Crowe type III dysplasia and nine had Crowe type IV. Cementless acetabular components with standard polyethylene liners were introduced as close to the level of the true acetabulum as possible. The modular cementless S-ROM femoral component was used with a low resection of the femoral neck. A total of 21 patients (25 THRs) were available for review at a mean follow-up of 18.7 years (15.8 to 21.8). The mean modified Harris hip score improved from 46 points pre-operatively to 90 at final follow up (p < 0.001). . A total of 15 patients (17 THRs; 57%) underwent revision of the acetabular component at a mean of 14.6 years (7 to 20.8), all for osteolysis. Two patients (two THRs) had symptomatic loosening. No patient underwent femoral revision. Survival with revision of either component for any indication was 81% at 15 years (95% CI 60.1 to 92.3), with 21 patients at risk. . This technique may reduce the need for femoral osteotomy in severe DDH, while providing a good long-term functional result. Cite this article: Bone Joint J 2014;96-B:1449–54

We compared a modular neck system with a non-modular system in a cementless anatomical total hip replacement (THR). Each group consisted of 74 hips with developmental hip dysplasia. Both groups had the same cementless acetabular component and the same articulation, which consisted of a conventional polyethylene liner and a 28 mm alumina head. The mean follow-up was 14.5 years (13 to 15), at which point there were significant differences in the mean total Harris hip score (modular/non-modular: 98.6 (64 to 100)/93.8 (68 to 100)), the mean range of abduction (32° (15° to 40°)/28 (0° to 40°)), use of a 10° elevated liner (31%/100%), the incidence of osteolysis (27%/79.7%) and the incidence of equal leg lengths (≥ 6 mm, 92%/61%). There was no disassociation or fracture of the modular neck. The modular system reduces the need for an elevated liner, thereby reducing the incidence of osteolysis. It gives a better range of movement and allows the surgeon to make an accurate adjustment of leg length

Pre-operative computerised three-dimensional planning was carried out in 223 patients undergoing total hip replacement with a cementless acetabular component and a cementless modular-neck femoral stem. Components were chosen which best restored leg length and femoral offset. The post-operative restoration of the anatomy was assessed by CT and compared with the pre-operative plan. The component implanted was the same as that planned in 86% of the hips for the acetabular implant, 94% for the stem, and 93% for the neck-shaft angle. The rotational centre of the hip was restored with a mean accuracy of 0.73 mm (. sd. 3.5) craniocaudally and 1.2 mm (. sd. 2) laterally. Limb length was restored with a mean accuracy of 0.3 mm (. sd. 3.3) and femoral offset with a mean accuracy of 0.8 mm (. sd. 3.1). This method appears to offer high accuracy in hip reconstruction as the difficulties likely to be encountered when restoring the anatomy can be anticipated and solved pre-operatively by optimising the selection of implants. Modularity of the femoral neck helped to restore the femoral offset and limb length

Aims. It may not be possible to undertake revision total hip arthroplasty (THA) in the presence of massive loss of acetabular bone stock using standard cementless hemispherical acetabular components and metal augments, as satisfactory stability cannot always be achieved. We aimed to study the outcome using a reconstruction cage and a porous metal augment in these patients. Patients and Methods. A total of 22 acetabular revisions in 19 patients were performed using a combination of a reconstruction cage and porous metal augments. The augments were used in place of structural allografts. The mean age of the patients at the time of surgery was 70 years (27 to 85) and the mean follow-up was 39 months (27 to 58). The mean number of previous THAs was 1.9 (1 to 3). All patients had segmental defects involving more than 50% of the acetabulum and seven hips had an associated pelvic discontinuity. . Results. Three failures were observed in two hips, both of which had undergone a previous resection of a tumour affecting the acetabulum. Other complications included a late arterial injury, a sciatic nerve palsy, a dislocation treated with a femoral revision, a deep infection treated with irrigation and debridement and a fracture of the greater trochanter treated conservatively. The mean Oxford Hip Score significantly increased from 13.9 (2 to 23) to 28.7 (13 to 38) (p < 0.00001). The mean vertical distance between the centre of rotation of the hip and its normal location decreased from 30 mm to 10 mm. Conclusions. Acceptable early survivorship can be achieved using this novel technique, but it may be unsuitable for use in patients who have previously undergone the resection of a tumour involving the acetabulum. Cite this article: Bone Joint J 2017;99-B:607–13

We reviewed 80 patients (87 hips) who were older than 80 years of age at the time of cementless total hip arthroplasty. An Alloclassic SL stem had been implanted in all patients. A variety of cementless acetabular components was used. After a mean follow-up of 69.3 months (39.2 to 94.1) 48 hips in 43 patients were analysed clinically and radiologically. One patient had sustained a traumatic periprosthetic fracture of the femur with subsequent exchange of the stem 73 months after operation. Thirty-two patients (34 hips) had died and five patients (five hips) were unavailable for follow-up because of health reasons (four patients) or lack of co-operation (one patient). If the endpoint is defined as removal of the prosthesis because of aseptic loosening, the survival rate was 100% for the cup and stem after 78 months. The mean Harris hip score was 81.9 points. Radiolucent lines and osteolysis were seldom found

We investigated the rate of polyethylene wear of a cementless acetabular component at different periods of follow-up in order to test the hypothesis than an irrecoverable deformation process (creep) was followed by an initially low, but gradually increasing wear rate. We studied prospectively 93 uncemented total hip arthroplasties in 83 patients (mean age 50 years (22 to 63)) with a mean follow-up of 8.2 years (3 to 12). We measured the penetration of the femoral head from radiographs taken immediately after surgery at three, six and nine years, or at the latest follow-up. The median wear rate was 0.17 mm per year in the first three years, a finding which we considered to be caused by creep. Thereafter, the rate of wear declined to 0.07 mm per year (four- to six-year period) and then increased to 0.17 mm per year (seven to nine years) and 0.27 mm per year (more than nine years), which we considered to be a reflection of genuine polyethylene wear. After the nine-year follow-up the wear rates were higher in patients with marked osteolysis. We found no relationship between the inclination angle of the acetabular component or femoral head orientation and the rate of wear. No acetabular component required revision

Aims

Manual impaction, with a mallet and introducer, remains the standard method of installing cementless acetabular cups during total hip arthroplasty (THA). This study aims to quantify the accuracy and precision of manual impaction strikes during the seating of an acetabular component. This understanding aims to help improve impaction surgical techniques and inform the development of future technologies.

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The aim of the study was to investigate whether the primary stability of press-fit acetabular components can be improved by altering the impaction procedure.

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The aim of this study was to compare the pattern of initial fixation and changes in periprosthetic bone mineral density (BMD) between patients who underwent total hip arthroplasty (THA) using a traditional fully hydroxyapatite (HA)-coated stem (T-HA group) and those with a newly introduced fully HA-coated stem (N-HA group).

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The objective of this study was to compare the two-year migration and clinical outcomes of a new cementless hydroxyapatite (HA)-coated titanium acetabular shell with its previous version, which shared the same geometrical design but a different manufacturing process for applying the titanium surface.

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The aim of this study was to compare open reduction and internal fixation (ORIF) with revision surgery for the surgical management of Unified Classification System (UCS) type B periprosthetic femoral fractures around cemented polished taper-slip femoral components following primary total hip arthroplasty (THA).

Aims

The Exeter short stem was designed for patients with Dorr type A femora and short-term results are promising. The aim of this study was to evaluate the minimum five-year stem migration pattern of Exeter short stems in comparison with Exeter standard stems.

Aims

BoneMaster is a thin electrochemically applied hydroxyapatite (HA) coating for orthopaedic implants that is quickly resorbed during osseointegration. Early stabilization is a surrogacy marker of good survival of femoral stems. The hypothesis of this study was that a BoneMaster coating yields a fast early and lasting fixation of stems.

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This study aimed to evaluate the accuracy of implant placement with robotic-arm assisted total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH).

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The aim of this study was to determine whether total hip arthroplasty (THA) for chronic hip pain due to unilateral primary osteoarthritis (OA) has a beneficial effect on cognitive performance.

Aims

Improvements in functional results and long-term survival are variable following conversion of hip fusion to total hip arthroplasty (THA) and complications are high. The aim of the study was to analyze the clinical and functional results in patients who underwent conversion of hip fusion to THA using a consistent technique and uncemented implants.

Aims

We aimed to investigate if the use of the largest possible cobalt-chromium head articulating with polyethylene acetabular inserts would increase the in vivo wear rate in total hip arthroplasty.

Aims

Adverse local tissue reactions associated with abnormal wear considerably slowed down the general use of metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), now limited to a few specialized centres. In this study, we provide the clinical results of 400 consecutive MoM HRAs implanted more than 20 years ago in one such centre.

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To compare the in vivo long-term fixation achieved by two acetabular components with different porous ingrowth surfaces using radiostereometric analysis (RSA).

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We present the results, in terms of survival, clinical outcome, and radiological appearance at 20 years, in a cohort of 225 cemented Exeter Universal femoral components (Stryker, Newbury, UK) implanted in 207 patients, at a district general hospital.

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To our knowledge, no study has compared the long-term results of cemented and hybrid total hip arthroplasty (THA) in patients with osteoarthritis (OA) secondary to congenital hip disease (CHD). This is a demanding procedure that may require special techniques and implants. Our aim was to compare the long-term outcome of cemented low-friction arthroplasty (LFA) and hybrid THA performed by one surgeon.

Aims

Various surgical techniques have been described for total hip arthroplasty (THA) in patients with Crowe type III dislocated hips, who have a large acetabular bone defect. The aim of this study was to evaluate the long-term clinical results of patients in whom anatomical reconstruction of the acetabulum was performed using a cemented acetabular component and autologous bone graft from the femoral neck.

Aims

The main aims were to identify risk factors predictive of a radiolucent line (RLL) around the acetabular component with an interface bioactive bone cement (IBBC) technique in the first year after THA, and evaluate whether these risk factors influence the development of RLLs at five and ten years after THA.

Aims

Dual mobility (DM) implants have been shown to reduce the dislocation rate after total hip arthroplasty (THA), but there remain concerns about the use of cobalt chrome liners inserted into titanium shells. The aim of this study was to assess the clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) at mid-term follow-up in young, active patients receiving a modular DM THA.

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The aim of this study was to identify the effect of the manufacturing characteristics of polyethylene acetabular liners on the survival of cementless and hybrid total hip arthroplasty (THA).

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We aimed to report the mid- to long-term rates of septic and aseptic failure after two-stage revision surgery for periprosthetic joint infection (PJI) following total hip arthroplasty (THA).

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Although periarticular injection plays an important role in multimodal pain management following total hip arthroplasty (THA), there is no consensus on the optimal composition of the injection. In particular, it is not clear whether the addition of a corticosteroid improves the pain relief achieved nor whether it is associated with more complications than are observed without corticosteroid. The aim of this study was to quantify the safety and effectiveness of cortocosteroid use in periarticular injection during THA.

Aims

To compare long-term survival of all-cemented and hybrid total hip arthroplasty (THA) using the Exeter Universal stem.

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The aim of this study was to report the initial results of the Exeter V40 stem, which became available in 2000.

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This study aimed to explore whether intraoperative nerve monitoring can identify risk factors and reduce the incidence of nerve injury in patients with high-riding developmental dysplasia.

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Osteolysis, secondary to local and systemic physiological effects, is a major challenge in total hip arthroplasty (THA). While osteolytic defects are commonly observed in long-term follow-up, how such lesions alter the distribution of stress is unclear. The aim of this study was to quantitatively describe the biomechanical implication of such lesions by performing subject-specific finite-element (FE) analysis on patients with osteolysis after THA.

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The classical longitudinal incision used for the direct anterior approach (DAA) to the hip does not follow the tension lines of the skin and can lead to impaired wound healing and poor cosmesis. The purpose of this retrospective study was to determine the satisfaction with the scar, and functional and radiographic outcomes comparing the classic longitudinal incision with a modified skin crease ‘bikini’ when the DAA is used for total hip arthroplasty (THA).

Aims

Vitamin E-diffused, highly crosslinked polyethylene (VEPE) and porous titanium-coated (PTC) shells were introduced in total hip arthroplasty (THA) to reduce the risk of aseptic loosening. The purpose of this study was: 1) to compare the wear properties of VEPE to moderately crosslinked polyethylene; 2) to assess the stability of PTC shells; and 3) to report their clinical outcomes at seven years.

Aims

Custom flange acetabular components (CFACs) are a patient-specific option for addressing large acetabular defects at revision total hip arthroplasty (THA), but patient and implant characteristics that affect survivorship remain unknown. This study aimed to identify patient and design factors related to survivorship.

Aims

This single-centre observational study aimed to describe the results of extensive bone impaction grafting of the whole acetabular cavity in combination with an uncemented component in acetabular revisions performed in a standardized manner since 1993.

Aims

Modular dual mobility (DM) prostheses in which a cobalt-chromium liner is inserted into a titanium acetabular shell (vs a monoblock acetabular component) have the advantage of allowing supplementary screw fixation, but the potential for corrosion between the liner and acetabulum has raised concerns. While DM prostheses have shown improved stability in patients deemed ‘high-risk’ for dislocation undergoing total hip arthroplasty (THA), their performance in young, active patients has not been reported. This study’s purpose was to assess clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) in young, active patients receiving a modular DM acetabulum and recently introduced titanium, proximally coated, tapered femoral stem design.

Aims

Tantalum (Ta) trabecular metal components are increasingly used to reconstruct major bone defects in revision arthroplasty surgery. It is known that some metals such as silver have antibacterial properties. Recent reports have raised the question regarding whether Ta components are protective against infection in revision surgery. This laboratory study aimed to establish whether Ta has intrinsic antibacterial properties against planktonic bacteria, or the ability to inhibit biofilm formation.

Aims

The aim of this study was to evaluate blood metal ion levels, leucocyte profiles, and serum cytokines in patients with a total hip arthroplasty (THA) involving modular dual-mobility components.

Aims

The advent of trabecular metal (TM) augments has revolutionized the management of severe bone defects during acetabular reconstruction. The purpose of this study was to evaluate patients undergoing revision total hip arthroplasty (THA) with the use of TM augments for reconstruction of Paprosky IIIA and IIIB defects.

Aims

Modular dual-mobility constructs reduce the risk of dislocation after revision total hip arthroplasty (THA). However, questions about metal ions from the cobalt-chromium (CoCr) liner persist, and are particularly germane to patients being revised for adverse local tissue reactions (ALTR) to metal. We determined the early- to mid-term serum Co and Cr levels after modular dual-mobility components were used in revision and complex primary THAs, and specifically included patients revised for ALTR.

Aims

The aims of this study were to determine the clinical and radiographic outcomes, implant survivorship, and complications of patients with a history of poliomyelitis undergoing total hip arthroplasty (THA) in affected limbs and unaffected limbs of this same population.

Aims

The aim of this study was to compare the incidence of aseptic loosening after the use of a cemented acetabular component and a Trabecular Metal (TM) acetabular component (Zimmer Inc., Warsaw, Indiana) at acetabular revision with bone impaction grafting.

Aims

Our aim was to report survivorship data and lessons learned with the Corail/Pinnacle cementless total hip arthroplasty (THA) system.

Aims

Severe acetabular bone loss and pelvic discontinuity (PD) present particular challenges in revision total hip arthroplasty. To deal with such complex situations, cup-cage reconstruction has emerged as an option for treating this situation. We aimed to examine our success in using this technique for these anatomical problems.

Aims

The aim of this study was to identify patient- and surgery-related risk factors for sustaining an early periprosthetic fracture following primary total hip arthroplasty (THA) performed using a double-tapered cementless femoral component (Bi-Metric femoral stem; Biomet Inc., Warsaw, Indiana).

Aims

Post-operative migration of cemented acetabular components as measured by radiostereometric analysis (RSA) has a strong predictive power for late, aseptic loosening. Also, radiolucent lines predict late loosening. Migration has been reduced by systemic bisphosphonate treatment in randomised trials of hip and knee arthroplasty. Used as a local treatment, a higher local dose of bisphosphonate can be achieved without systemic exposure. We wished to see if this principle could be applied usefully in total hip arthroplasty (THA).

Aims

Advocates of debridement, antibiotics and implant retention (DAIR) in hip periprosthetic joint infection (PJI) argue that a procedure not disturbing a sound prosthesis-bone interface is likely to lead to better survival and functional outcome compared with revision. This case-control study aims were to compare outcome of DAIRs for infected primary total hip arthroplasty (THA) with outcomes following primary THA and two-stage revision of infected primary THAs.

Ideal placement of the acetabular component remains elusive both in terms of defining and achieving a target. Our aim is to help restore original anatomy by using the transverse acetabular ligament (TAL) to control the height, depth and version of the component. In the normal hip the TAL and labrum extend beyond the equator of the femoral head and therefore, if the definitive acetabular component is positioned such that it is cradled by and just deep to the plane of the TAL and labrum and is no more than 4mm larger than the original femoral head, the centre of the hip should be restored. If the face of the component is positioned parallel to the TAL and psoas groove the patient specific version should be restored. We still use the TAL for controlling version in the dysplastic hip because we believe that the TAL and labrum compensate for any underlying bony abnormality.

The TAL should not be used as an aid to inclination. Worldwide, > 75% of surgeons operate with the patient in the lateral decubitus position and we have shown that errors in post-operative radiographic inclination (RI) of > 50° are generally caused by errors in patient positioning. Consequently, great care needs to be taken when positioning the patient. We also recommend 35° of apparent operative inclination (AOI) during surgery, as opposed to the traditional 45°.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):37–43.

We describe our technique and rationale using hybrid fixation for primary total hip arthroplasty (THA) at the Hospital for Special Surgery. Modern uncemented acetabular components have few screw holes, or no holes, polished inner surfaces, improved locking mechanisms, and maximised thickness and shell-liner conformity. Uncemented sockets can be combined with highly cross-linked polyethylene liners, which have demonstrated very low wear and osteolysis rates after ten to 15 years of implantation. The results of cement fixation with a smooth or polished surface finished stem have been excellent, virtually eliminating complications seen with cementless fixation like peri-operative femoral fractures and thigh pain. Although mid-term results of modern cementless stems are encouraging, the long-term data do not show reduced revision rates for cementless stems compared with cemented smooth stems. In this paper we review the conduct of a hybrid THA, with emphasis on pre-operative planning, surgical technique, hypotensive epidural anaesthesia, and intra-operative physiology.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):54–9.

We studied 33 third generation, alumina ceramic-on-ceramic bearings retrieved from cementless total hip replacements after more than six months in situ. Wear volume was measured with a Roundtest machine, and acetabular orientation from the anteroposterior pelvic radiograph. The overall median early wear rate was 0.1 mm³/yr for the femoral heads, and 0.04 mm³/yr for the acetabular liners. We then excluded hips where the components had migrated. In this stable subgroup of 22 bearings, those with an acetabular anteversion of < 15° (seven femoral heads) had a median femoral head wear rate of 1.2 mm³/yr, compared with 0 mm³/yr for those with an anteversion of ≥15° (15 femoral heads, p < 0.001). Even under edge loading, wear volumes with ceramic-on-ceramic bearings are small in comparison to other bearing materials. Low acetabular anteversion is associated with greater wear.

We reviewed the results at nine to 13 years of 125 total hip replacements in 113 patients using the monoblock uncemented Morscher press-fit acetabular component. The mean age at the time of operation was 56.9 years (36 to 74). The mean clinical follow-up was 11 years (9.7 to 13.5) and the mean radiological follow-up was 9.4 years (7.7 to 13.1). Three hips were revised, one immediately for instability, one for excessive wear and one for deep infection.

No revisions were required for aseptic loosening. A total of eight hips (7.0%) had osteolytic lesions greater than 1 cm, in four around the acetabular component (3.5%). One required bone grafting behind a well-fixed implant. The mean wear rate was 0.11 mm/year (0.06 to 0.78) and was significantly higher in components with a steeper abduction angle.

Kaplan-Meier survival curves at 13 years showed survival of 96.8% (95% confidence interval 90.2 to 99.0) for revision for any cause and of 95.7% (95% confidence interval 88.6 to 98.4) for any acetabular re-operation.

We have reviewed 70 Harris-Galante uncemented acetabular components implanted as hybrid hip replacements with cemented stems between 1991 and 1995 in 53 patients whose mean age was 40 years (19 to 49). The mean follow-up was for 13.6 years (12 to 16) with no loss to follow-up. We assessed the patients both clinically and radiologically.

The mean Oxford hip score was 20 (12 to 46) and the mean Harris hip score 81 (37 to 100) at the final review. Radiologically, 27 hips (39%) had femoral osteolysis, 13 (19%) acetabular osteolysis, and 31 (44%) radiolucent lines around the acetabular component. Kaplan-Meier survival curves were constructed for the outcomes of revision of the acetabular component, revision of the component and polyethylene liner, and impending revision for progressive osteolysis.

The cumulative survival for revision of the acetabular component was 94% (95% confidence interval 88.4 to 99.7), for the component and liner 84% (95% confidence interval 74.5 to 93.5) and for impending revision 55.3% (95% confidence interval 40.6 to 70) at 16 years.

Uncemented acetabular components with polyethylene liners undergo silent lysis and merit regular long-term radiological review.

There is no single standardised method of measuring the orientation of the acetabular component on plain radiographs after total hip arthroplasty. We assessed the reliability and accuracy of three methods of assessing anteversion of the acetabular component for 551 THAs using the PolyWare software and the methods of Liaw et al, and of Woo and Morrey. All measurements of the three methods had excellent intra- and inter-observer reliability. The values of the PolyWare software, which determines version of the acetabular component by edge detection were regarded as the reference standard. Although the PolyWare software and the method of Liaw et al were similarly precise, the method of Woo and Morrey was significantly less accurate (p < 0.001). The method of Liaw et al seemed to be more accurate than that of Woo and Morrey when compared with the measurements using the PolyWare software. If the qualified lateral radiograph was selected, anteversion measured using the method of Woo and Morrey was considered to be relatively reliable.

Cite this article: Bone Joint J 2015; 97-B:611–16.

Dysplasia of the hip, hypotonia, osteopenia, ligamentous laxity, and mental retardation increase the complexity of performing and managing patients with Down syndrome who require total hip replacement (THR). We identified 14 patients (six males, eight females, 21 hips) with Down syndrome and degenerative disease of the hip who underwent THR, with a minimum follow-up of two years from 1969 to 2009. In seven patients, bilateral THRs were performed while the rest had unilateral THRs. The mean clinical follow-up was 5.8 years (standard deviation (sd) 4.7; 2 to 17). The mean Harris hip score was 37.9 points (sd 7.8) pre-operatively and increased to 89.2 (sd 12.3) at final follow-up (p = 1x10^-9). No patient suffered a post-operative dislocation. In three patients, four hips had revision THR for aseptic loosening at a mean follow-up of 7.7 years (sd 6.3; 3 to 17). This rate of revision THR was higher than expected. Our patients with Down syndrome benefitted clinically from THR at mid-term follow-up.

Cite this article: Bone Joint J 2014;96-B:1455–8.

Juvenile idiopathic arthritis (JIA) is a chronic disease of childhood; it causes joint damage which may require surgical intervention, often in the young adult. The aim of this study was to describe the long-term outcome and survival of hip replacement in a group of adult patients with JIA and to determine predictors of survival for the prosthesis. In this retrospective comparative study patients were identified from the database of a regional specialist adult JIA clinic. This documented a series of 47 hip replacements performed in 25 adult patients with JIA. Surgery was performed at a mean age of 27 years (11 to 47), with a mean follow-up of 19 years (2 to 36). The mean Western Ontario and McMaster Universities osteoarthritis index questionnaire (WOMAC) score at the last follow-up was 53 (19 to 96) and the mean Health Assessment Questionnaire score was 2.25 (0 to 3). The mean pain component of the WOMAC score (60 (20 to 100)) was significantly higher than the mean functional component score (46 (0 to 97)) (p = 0.02). Kaplan-Meier survival analysis revealed a survival probability of 46.6% (95% confidence interval 37.5 to 55.7) at 19 years, with a trend towards enhanced survival with the use of a cemented acetabular component and a cementless femoral component. This was not, however, statistically significant (acetabular component, p = 0.76, femoral component, p = 0.45). Cox’s proportional hazards regression analysis showed an implant survival rate of 54.9% at 19 years at the mean of covariates.

Survival of the prosthesis was significantly poorer (p = 0.001) in patients who had been taking long-term corticosteroids and significantly better (p = 0.02) in patients on methotrexate.

Total hip replacement (THR) still is a rare intervention in many African countries. In Burkina Faso it is not performed on a regular basis. A visiting programme for THR was started in a district hospital with no previous relevant experience. In this paper we present an analysis of the surgical technical problems and peri-operative complications of 152 THRs in 136 patients and three bipolar hemiarthroplasties in three patients undertaken in this new programme with limited orthopaedic equipment. There were 86 male and 53 female patients with a mean age of 49 years (21 to 78). We identified 77 intra-operative technical problems in 51 operations. There were 24 peri-operative complications in 21 patients, 17 of which were bony in nature. So far, ten revision THRs have been performed in nine patients.

Regular analysis of the technical problems and complications was used to improve quality, and we identified patient selection adapted to the local circumstances as important to avoid complications. Our reflections on the problems encountered in initiating such a programme may be of help to other teams planning similar projects.

Cite this article: Bone Joint J 2014;96-B:177–80.

Pelvic discontinuity with associated bone loss is a complex challenge in acetabular revision surgery. Reconstruction using ilio-ischial cages combined with trabecular metal acetabular components and morsellised bone (the component-cage technique) is a relatively new method of treatment.

We reviewed a consecutive series of 26 cases of acetabular revision reconstructions in 24 patients with pelvic discontinuity who had been treated by the component-cage technique. The mean follow-up was 44.6 months (24 to 68). Failure was defined as migration of a component of > 5 mm.

In 23 hips (88.5%) there was no clinical or radiological evidence of loosening at the last follow-up. The mean Harris hip score improved significantly from 46.6 points (29.5 to 68.5) to 76.6 points (55.5 to 92.0) at two years (p < 0.001). In three hips (11.5%) the construct had migrated at one year after operation. The complications included two dislocations, one infection and one partial palsy of the peroneal nerve.

Our findings indicate that treatment of pelvic discontinuity using the component-cage construct is a reliable option.

There are few reports describing the technique of managing acetabular protrusio in primary total hip replacement. Most are small series with different methods of addressing the challenges of significant medial and proximal migration of the joint centre, deficient medial bone and reduced peripheral bony support to the acetabular component. We describe our technique and the clinical and radiological outcome of using impacted morsellised autograft with a porous-coated cementless cup in 30 primary THRs with mild (n = 8), moderate (n = 10) and severe (n = 12) grades of acetabular protrusio. The mean Harris hip score had improved from 52 pre-operatively to 85 at a mean follow-up of 4.2 years (2 to 10). At final follow-up, 27 hips (90%) had a good or excellent result, two (7%) had a fair result and one (3%) had a poor result. All bone grafts had united by the sixth post-operative month and none of the hips showed any radiological evidence of recurrence of protrusio, osteolysis or loosening. By using impacted morsellised autograft and cementless acetabular components it was possible to achieve restoration of hip mechanics, provide a biological solution to bone deficiency and ensure long-term fixation without recurrence in arthritic hips with protrusio undergoing THR.

Cite this article: Bone Joint J 2013;95-B, Supple A:37–40.

The increasing need for total hip replacement (THR) in an ageing population will inevitably generate a larger number of revision procedures. The difficulties encountered in dealing with the bone deficient acetabulum are amongst the greatest challenges in hip surgery. The failed acetabular component requires reconstruction to restore the hip centre and improve joint biomechanics. Impaction bone grafting is successful in achieving acetabular reconstruction using both cemented and cementless techniques. Bone graft incorporation restores bone stock whilst providing good component stability. We provide a summary of the evidence and current literature regarding impaction bone grafting using both cemented and cementless techniques in revision THR.

Cite this article: Bone Joint J 2013;95-B, Supple A:98–102.

In a time of limited resources, the debate continues over which types of hip prosthesis are clinically superior and more cost-effective. Orthopaedic surgeons increasingly need robust economic evidence to understand the full value of the operation, and to aid decision making on the ‘package’ of procedures that are available and to justify their practice beyond traditional clinical preference.

In this paper we explore the current economic debate about the merits of cemented and cementless total hip replacement, an issue that continues to divide the orthopaedic community.

Cite this article: Bone Joint J 2013;95-B:874–6.

Down’s syndrome is associated with a number of musculoskeletal abnormalities, some of which predispose patients to early symptomatic arthritis of the hip. The purpose of the present study was to review the general and hip-specific factors potentially compromising total hip replacement (THR) in patients with Down’s syndrome, as well as to summarise both the surgical techniques that may anticipate the potential adverse impact of these factors and the clinical results reported to date. A search of the literature was performed, and the findings further informed by the authors’ clinical experience, as well as that of the hip replacement in Down Syndrome study group. The general factors identified include a high incidence of ligamentous laxity, as well as associated muscle hypotonia and gait abnormalities. Hip-specific factors include: a high incidence of hip dysplasia, as well as a number of other acetabular, femoral and combined femoroacetabular anatomical variations. Four studies encompassing 42 hips, which reported the clinical outcomes of THR in patients with Down’s syndrome, were identified. All patients were successfully treated with standard acetabular and femoral components. The use of supplementary acetabular screw fixation to enhance component stability was frequently reported. The use of constrained liners to treat intra-operative instability occurred in eight hips. Survival rates of between 81% and 100% at a mean follow-up of 105 months (6 to 292) are encouraging. Overall, while THR in patients with Down’s syndrome does present some unique challenges, the overall clinical results are good, providing these patients with reliable pain relief and good function.

Cite this article: Bone Joint J 2013;95-B, Supple A:41–5.

We evaluated the use of a stemmed acetabular component in the treatment of severe acetabular deficiency during revision and complex primary total hip arthroplasty.

There were 31 hips of which 24 were revisions (20 for aseptic loosening, four for infection) and the remainder were complex primary arthroplasties. At a mean follow-up of 10.7 years (6 to 12.8), no component had been revised for aseptic loosening; one patient had undergone a revision of the polyethylene liner for wear. There was one failure because of infection. At the latest follow-up, the cumulative survival rate for aseptic loosening, with revision being the end-point, was 100%; for radiographic loosening it was 92% and for infection and radiographic loosening it was 88%. These results justify the continued use of this stemmed component for the reconstruction of severe acetabular deficiency.

We report the clinical and radiological outcomes of a series of contemporary cementless ceramic-on-ceramic total hip replacements (THRs) at ten years in patients aged ≤ 55 years of age. Pre- and post-operative activity levels are described. A total of 120 consecutive ceramic cementless THRs were performed at a single centre in 110 patients from 1997 to 1999. The mean age of the patients at operation was 45 years (20 to 55). At ten years, four patients had died and six were lost to follow-up, comprising ten hips. The mean post-operative Harris hip score was 94.7 (55 to 100). Radiological analysis was undertaken in 90 available THRs of the surviving 106 hips at final review: all had evidence of stable bony ingrowth, with no cases of osteolysis. Wear was undetectable. There were four revisions. The survival for both components with revision for any cause as an endpoint was 96.5% (95% confidence interval 94.5 to 98.7). The mean modified University of California, Los Angeles activity level rose from a mean of 6.4 (4 to 10) pre-operatively to 9.0 (6 to 10) at the ten-year post-operative period.

Alumina ceramic-on-ceramic bearings in cementless primary THR in this series have resulted in good clinical and radiological outcomes with undetectable rates of wear and excellent function in the demanding younger patient group at ten years.

Cite this article: Bone Joint J 2013;95-B:1603–9.

Between January 1998 and December 1998, 82 consecutive patients (86 hips) underwent total hip arthroplasty using a trabecular metal monoblock acetabular component. All patients had a clinical and radiological follow-up evaluation at six, 12 and 24 weeks, 12 months, and then annually thereafter. On the initial post-operative radiograph 25 hips had a gap between the outer surface of the component and the acetabular host bed which ranged from 1 to 5 mm. All patients were followed up clinically and radiologically for a mean of 7.3 years (7 to 7.5). The 25 hips with the 1 to 5 mm gaps were studied for component migration at two years using the Einzel-Bild-Roentgen-Analyse (EBRA) digital measurement method. At 24 weeks all the post-operative gaps were filled with bone and no acetabular component had migrated. The radiographic outcome of all 86 components showed no radiolucent lines and no evidence of lysis. No acetabular implant was revised. There were no dislocations or other complications. The bridging of the interface gaps (up to 5 mm) by the trabecular metal monoblock acetabular component indicates the strong osteoconductive, and possibly osteoinductive, properties of trabecular metal.

The outcome of total hip replacement (THR) is potentially affected by the body mass index (BMI) of the patient. We studied the outcome of 2026 consecutive primary cementless THRs performed for osteoarthritis. The mean follow-up was 6.3 years (0 to 11.71) and no patient was lost to follow-up for survival analysis. The patients were divided into two groups according to their BMI as follows: non-obese (BMI < 30 kg/m²) and obese (BMI ≥ 30 kg/m²).

The obese patient undergoing surgery was found to be significantly younger (p < 0.001). The log-rank test for equality of survival showed no difference in the mid-term survival (p = 0.552) with an estimated survival at 11 years of 95.2% (95% CI 92.5 to 98.0) in the non-obese and 96.7% (95% CI 94.9 to 98.5) in the obese groups. The clinical and radiological outcome was determined in a case-matched study performed on 134 obese individuals closely matched with 134 non-obese controls. The non-obese group was found to have a significantly higher post-operative Harris hip score (p < 0.001) and an increased range of movement, but overall satisfaction with surgery was comparable with that of the obese patients. Radiological analysis of the acetabular and femoral components showed no significant differences with regard to radiolucent lines, osteolysis, ingrowth of the femoral component, the acetabular inclination angle or alignment of the femoral component. Our results suggest that the survival of cementless THR is not adversely affected by obesity. Obese patients can therefore be counselled that despite a lower clinical score, they should expect to be satisfied with the result of their THR with a mid-term survival rate equivalent to that of non-obese patients.

Objectives

To quantify and compare peri-acetabular bone mineral density (BMD) between a monoblock acetabular component using a metal-on-metal (MoM) bearing and a modular titanium shell with a polyethylene (PE) insert. The secondary outcome was to measure patient-reported clinical function.

In this prospective study a total of 80 consecutive Chinese patients with Crowe type I or II developmental dysplasia of the hip were randomly assigned for hip resurfacing arthroplasty (HRA) or total hip replacement (THR).

Three patients assigned to HRA were converted to THR, and three HRA patients and two THR patients were lost to follow-up. This left a total of 34 patients (37 hips) who underwent HRA and 38 (39 hips) who underwent THR. The mean follow-up was 59.4 months (52 to 70) in the HRA group and 60.6 months (50 to 72) in the THR group. There was no failure of the prosthesis in either group. Flexion of the hip was significantly better after HRA, but there was no difference in the mean post-operative Harris hip scores between the groups. The mean size of the acetabular component in the HRA group was significantly larger than in the THR group (49.5 mm vs 46.1 mm, p = 0.001). There was no difference in the mean abduction angle of the acetabular component between the two groups.

Although the patients in this series had risk factors for failure after HRA, such as low body weight, small femoral heads and dysplasia, the clinical results of resurfacing in those with Crowe type I or II hip dysplasia were satisfactory. Patients in the HRA group had a better range of movement, although neck-cup impingement was observed. However, more acetabular bone was sacrificed in HRA patients, and it is unclear whether this will have an adverse effect in the long term.

We present our experience with a double-mobility acetabular component in 155 consecutive revision total hip replacements in 149 patients undertaken between 2005 and 2009, with particular emphasis on the incidence of further dislocation. The mean age of the patients was 77 years (42 to 89) with 59 males and 90 females. In all, five patients died and seven were lost to follow-up. Indications for revision were aseptic loosening in 113 hips, recurrent instability in 29, peri-prosthetic fracture in 11 and sepsis in two. The mean follow-up was 42 months (18 to 68). Three hips (2%) in three patients dislocated within six weeks of surgery; one of these dislocated again after one year. All three were managed successfully with closed reduction. Two of the three dislocations occurred in patients who had undergone revision for recurrent dislocation. All three were found at revision to have abductor deficiency. There were no dislocations in those revised for either aseptic loosening or sepsis.

These results demonstrate a good mid-term outcome for this component. In the 29 patients revised for instability, only two had a further dislocation, both of which were managed by closed reduction.

We report the use of porous metal acetabular revision shells in the treatment of contained bone loss. The outcomes of 53 patients with ≤ 50% acetabular bleeding host bone contact were compared with a control group of 49 patients with > 50% to 85% bleeding host bone contact. All patients were treated with the same type of trabecular metal acetabular revision shell. The mean age at revision was 62.4 years (42 to 80) and the mean follow-up of both groups was 72.4 months (60 to 102). Clinical, radiological and functional outcomes were assessed. There were four (7.5%) mechanical failures in the ≤ 50% host bone contact group and no failures in the > 50% host bone contact group (p = 0.068). Out of both groups combined there were four infections (3.9%) and five recurrent dislocations (4.9%) with a stable acetabular component construct that were revised to a constrained liner. Given the complexity of the reconstructive challenge, porous metal revision acetabular shells show acceptable failure rates at five to ten years’ follow-up in the setting of significant contained bone defects. This favourable outcome might be due to the improved initial stability achieved by a high coefficient of friction between the acetabular implant and the host bone, and the high porosity, which affords good bone ingrowth.

This study reviewed the results of a cementless anatomical femoral component to give immediate post-operative stability, and with a narrow distal section in order not to contact the femoral cortex in the diaphysis, ensuring exclusively metaphyseal loading.

A total of 471 patients (601 hips) who had a total hip replacement between March 1995 and February 2002 were included in the study. There were 297 men and 174 women. The mean age at the time of operation was 52.7 years (28 to 63). Clinical and radiological evaluation were performed at each follow-up. Bone densitometry was carried out on all patients two weeks after operation and at the final follow-up examination. The mean follow-up was 8.8 years (5 to 12).

The mean pre-operative Harris hip score was 41 points (16 to 54), which improved to a mean of 96 (68 to 100) at the final follow-up. No patient complained of thigh pain at any stage. No acetabular or femoral osteolysis was observed and no hip required revision for aseptic loosening of either component. Deep infection occurred in two hips (0.3%) which required revision. One hip (0.2%) required revision of the acetabular component for recurrent dislocation. Bone mineral densitometry revealed a minimal bone loss in the proximal femur.

This cementless anatomical femoral component with metaphyseal loading but without distal fixation produced satisfactory fixation and encourages proximal femoral loading.

We retrospectively reviewed 40 hips in 36 patients who had undergone acetabular reconstruction using a titanium Kerboull-type acetabular reinforcement device with bone allografts between May 2001 and April 2006. Impacted bone allografts were used for the management of American Academy of Orthopaedic Surgeons Type II defects in 17 hips, and bulk bone allografts together with impacted allografts were used for the management of Type III defects in 23 hips. A total of five hips showed radiological failure at a mean follow-up of 6.7 years (4.5 to 9.3), two of which were infected. The mean pre-operative Merle d’Aubigné score was 10 (5 to 15) vs 13.6 (9 to 18) at the latest follow-up. The Kaplan-Meier survival rate at ten years, calculated using radiological failure or revision of the acetabular component for any reason as the endpoint, was 87% (95% confidence interval 76.3 to 97.7). A separate experimental analysis of the mechanical properties of the device and the load-displacement properties of bone grafts showed that a structurally hard allograft resected from femoral heads of patients with osteoarthritis should be preferentially used in any type of defect. If impacted bone allografts were used, a bone graft thickness of < 25 mm was acceptable in Type II defects.

This clinical study indicates that revision total hip replacement using the Kerboull-type acetabular reinforcement device with bone allografts yielded satisfactory mid-term results.

There is little evidence on the cost effectiveness of different brands of hip prostheses. We compared lifetime cost effectiveness of frequently used brands within types of prosthesis including cemented (Exeter V40 Contemporary, Exeter V40 Duration and Exeter V40 Elite Plus Ogee), cementless (Corail Pinnacle, Accolade Trident, and Taperloc Exceed) and hybrid (Exeter V40 Trilogy, Exeter V40 Trident, and CPT Trilogy). We used data from three linked English national databases to estimate the lifetime risk of revision, quality-adjusted life years (QALYs) and cost.

For women with osteoarthritis aged 70 years, the Exeter V40 Elite Plus Ogee had the lowest risk of revision (5.9% revision risk, 9.0 QALYs) and the CPT Trilogy had the highest QALYs (10.9% revision risk, 9.3 QALYs). Compared with the Corail Pinnacle (9.3% revision risk, 9.22 QALYs), the most commonly used brand, and assuming a willingness-to-pay of £20 000 per QALY gain, the CPT Trilogy is most cost effective, with an incremental net monetary benefit of £876. Differences in cost effectiveness between the hybrid CPT Trilogy and Exeter V40 Trident and the cementless Corail Pinnacle and Taperloc Exceed were small, and a cautious interpretation is required, given the limitations of the available information.

However, it is unlikely that cemented brands are among the most cost effective. Similar patterns of results were observed for men and other ages. The gain in quality of life after total hip arthroplasty, rather than the risk of revision, was the main driver of cost effectiveness.

Cite this article: Bone Joint J 2015;97-B:762–70.

We report the outcome of the flangeless, cemented all-polyethylene Exeter acetabular component at a mean of 14.6 years (10 to 17) after operation. Of the 263 hips in 243 patients, 122 prostheses are still in situ; 112 patients (119 hips) have died, 18 hips have been revised, and three patients (four hips) were lost to follow-up. Radiographs at the final review were available for 110 of the 122 surviving hips. There were acetabular radiolucent lines in 54 hips (49%). Two acetabular components had migrated but neither patient required revision. The Kaplan-Meier survivorship at 15 years with 61 hips at risk with revision for any cause as the endpoint was 89.9% (95% confidence interval (CI) 84.6 to 95.2) and for aseptic loosening of the acetabular component or lysis 91.7% (95% CI 86.6 to 96.8). In 210 hips with a diagnosis of primary osteoarthritis, survivorship with revision for any cause as the endpoint was 93.2% (95% CI 88.1 to 98.3), and for aseptic loosening of the acetabular component 95.0% (95% CI 90.3 to 99.7).

The cemented all-polyethylene Exeter acetabular component has an excellent long-term survivorship.

Periprosthetic infection following total hip replacement can be a catastrophic complication for the patient. The treatments available include single-stage exchange, and two-stage exchange. We present a series of 50 consecutive patients with a diagnosis of infected total hip replacement who were assessed according to a standardised protocol. Of these, 11 underwent single-stage revision arthroplasty with no recurrence of infection at a mean of 6.8 years follow-up (5.5 to 8.8). The remaining 39 underwent two-stage revision, with two recurrences of infection successfully treated by a second two-stage procedure. At five years, significant differences were found in the mean Harris Hip Scores (single-stage 87.8; two-stage 75.5; p = 0.0003) and in a visual analogue score for satisfaction (8.6; 6.9; p = 0.001) between the single- and two-stage groups. Single-stage exchange is successful in eradicating periprosthetic infection and results in excellent functional and satisfaction scores.

Identification of patients suitable for the single-stage procedure allows individualisation of care and provides as many as possible with the correct strategy in successfully tackling their periprosthetic infection

We studied the effect of trochanteric osteotomy in 192 total hip replacements in 140 patients with congenital hip disease. There was bony union in 158 hips (82%), fibrous union in 29 (15%) and nonunion in five (3%). The rate of union had a statistically significant relationship with the position of reattachment of the trochanter, which depended greatly on the pre-operative diagnosis. The pre-operative Trendelenburg gait substantially improved in all three disease types (dysplasia, low and high dislocation) and all four categories of reattachment position. A persistent Trendelenburg gait post-operatively was noticed mostly in patients with defective union (fibrous or nonunion). Acetabular and femoral loosening had a statistically significant relationship with defective union and the position of reattachment of the trochanter.

These results suggest that the complications of trochanteric osteotomy in total hip replacement for patients with congenital hip disease are less important than the benefits of this surgical approach.

There have been comparatively few studies of the incidence of osteolysis and the survival of hybrid and cementless total hip replacements (THRs) in patients younger than 50 years of age. We prospectively reviewed 78 patients (109 hips) with a hybrid THR having a mean age of 43.4 years (21 to 50) and 79 patients (110 hips) with a cementless THR with a mean age of 46.8 years (21 to 49). The patients were evaluated clinically using the Harris hip score, the Western Ontario and McMaster Universities (WOMAC) osteoarthritis score and the University of California, Los Angeles (UCLA) activity score. Radiographs and CT scans were assessed for loosening and osteolysis. The mean follow-up was for 18.4 years (16 to 19) in both groups.

The mean post-operative Harris hip scores (91 points versus 90 points), the mean WOMAC scores (11 points versus 13 points) and UCLA activity scores (6.9 points versus 7.1 points) were similar in both groups. The revision rates of the acetabular component (13% versus 16%) and the femoral component (3% versus 4%), and the survival of the acetabular component (87% versus 84%) and the femoral component (97% versus 96%) were similar in both groups.

Although the long-term fixation of the acetabular metallic shell and the cemented and cementless femoral components was outstanding, wear and peri-acetabular osteolysis constitute the major challenges of THR in young patients.

Objectives

The accuracy and precision of two new methods of model-based radiostereometric analysis (RSA) were hypothesised to be superior to a plain radiograph method in the assessment of polyethylene (PE) wear.

Between December 2004 and June 2006, 136 patients (156 total hip replacements), were sent from the waiting list of the Cardiff Vale NHS Trust to the NHS Treatment Centre, Weston-super-Mare, in an attempt to reduce the waiting time for total hip replacement. Because of concerns about their outcome, each patient was contacted and invited to attend a review appointment with a consultant specialising in hip and revision hip replacement.

A total of 98 patients (113 hips) were reviewed after a mean of 23 months (11 to 30). There were 104 cemented hips, seven hybrid and two cementless. An acetabular inclination of > 55° was seen in 18 (16%). Radiolucent lines around the acetabular component were seen in 76 (67%). The femoral component was in more than 4° of varus in 47 (42%). The medial floor had been breached in 13 (12%) and there was a leg-length discrepancy of more than 1 cm in ten (9%). There were three dislocations, one femoral fracture, one pulmonary embolus, one deep infection and two superficial wound infections.

To date, 13% (15 hips) have been revised and a further 4% (five hips) await revision, mostly for a painful loose acetabular component. The revision rate far exceeds the 0.5% five-year failure rate reported in the Swedish Registry for the components used. This initiative and the consequent need for correction of the problems created, has significantly increased the workload of our unit.

Total hip replacement for high dislocation of the hip joint remains technically difficult in terms of preparation of the true acetabulum and restoration of leg length. We describe our experience of cementless total hip replacement combined with a subtrochanteric femoral shortening osteotomy in 20 hips with Crowe grade IV dislocation with a mean follow-up of 8.1 years (4 to 11.5). There was one man and 17 women with a mean age of 55 years (44 to 69) at the time of the operation.

After placment of the acetabular component at the site of the natural acetabulum, a cementless porous-coated cylindrical femoral component was implanted following a subtrochanteric femoral shortening osteotomy.

The mean Japanese Orthopedic Association hip score improved from a mean of 38 (22 to 62) to a mean of 83 points (55 to 98) at the final follow-up. The mean lengthening of the leg was 14.8 mm (−9 to 34) in patients with iliofemoral osteoarthritis and 35.3 mm (15 to 51) in patients with no arthritic changes. No nerve palsy was observed.

Total hip replacement combined with subtrochanteric shortening femoral osteotomy in this situation is beneficial in avoiding nerve injury and still permits valuable improvement in inequality of leg length.

We investigated the early results of modular porous metal components used in 23 acetabular reconstructions associated with major bone loss. The series included seven men and 15 women with a mean age of 67 years (38 to 81), who had undergone a mean of two previous revisions (1 to 7).

Based on Paprosky’s classification, there were 17 type 3A and six type 3B defects. Pelvic discontinuity was noted in one case. Augments were used in 21 hips to support the shell and an acetabular component-cage construct was implanted in one case. At a mean follow-up of 41 months (24 to 62), 22 components remained well fixed. Two patients required rerevision of the liners for prosthetic joint instability. Clinically, the mean Harris Hip Score improved from 43.0 pre-operatively (14 to 86) to 75.7 post-operatively (53 to 100). The mean pre-operative Merle d’Aubigné score was 8.2 (3 to 15) and improved to a mean of 13.7 (11 to 18) post-operatively.

These short-term results suggest that modular porous metal components are a viable option in the reconstruction of Paprosky type 3 acetabular defects. More data are needed to determine whether the system yields greater long-term success than more traditional methods, such as reconstruction cages and structural allografts.

The hip joint is commonly involved in multiple epiphyseal dysplasia and patients may require total hip replacement before the age of 30 years.

We retrospectively reviewed nine patients (16 hips) from four families. The diagnosis of multiple epiphyseal dysplasia was based on a family history, genetic counselling, clinical features and radiological findings. The mean age at surgery was 32 years (17 to 63), with a mean follow-up of 15.9 years (5.5 to 24).

Of the 16 hips, ten required revision at a mean of 12.5 years (5 to 15) consisting of complete revision of the acetabular component in three hips and isolated exchange of the liner in seven. No femoral component has loosened or required revision during the period of follow-up.

With revision for any reason, the 15-year survival was only 11.4% (95% confidence interval 1.4 to 21.4). However, when considering revision of the acetabular shell in isolation the survival at ten years was 93.7% (95% confidence interval 87.7 to 99.7), reducing to 76.7% (95% confidence interval 87.7 to 98.7) at 15 and 20 years, respectively.

The orientation of the acetabular component can influence both the short- and long-term outcomes of total hip replacement (THR). We performed a prospective, randomised, controlled trial of two groups, comprising of 40 patients each, in order to compare freehand introduction of the component with introduction using the transverse acetabular ligament (TAL) as a reference for anteversion. Anteversion and inclination were measured on pelvic radiographs.

With respect to anteversion, in the freehand group 22.5% of the components were outside the safe zone versus 0% in the transverse acetabular ligament group (p = 0.002). The mean angle of anteversion in the freehand group was 21° (2° to 35°) which was significantly higher compared with 17° (2° to 25°) in the TAL group (p = 0.004). There was a significant difference comparing the variations of both groups (p = 0.008).

With respect to inclination, in the freehand group 37.5% of the components were outside the safe zone versus 20% in the TAL group (p = 0.14). There was no significant difference regarding the accuracy or variation of the angle of inclination when comparing the two groups.

The transverse acetabular ligament may be used to obtain the appropriate anteversion when introducing the acetabular component during THR, but not acetabular component inclination.

Cite this article: Bone Joint J 2014;96-B:312–18.

Metal-on-metal total hip replacement has been targeted at younger patients with anticipated long-term survival, but the effect of the production of metal ions is a concern because of their possible toxicity to cells. We have reviewed the results of the use of the Ultima hybrid metal-on-metal total hip replacement, with a cemented polished tapered femoral component with a 28 mm diameter and a cobalt-chrome (CoCr) modular head, articulating with a 28 mm CoCr acetabular bearing surface secured in a titanium alloy uncemented shell.

Between 1997 and 2004, 545 patients with 652 affected hips underwent replacement using this system. Up to 31 January 2008, 90 (13.8%) hips in 82 patients had been revised. Pain was the sole reason for revision in 44 hips (48.9%) of which 35 had normal plain radiographs. Peri-prosthetic fractures occurred in 17 hips (18.9%) with early dislocation in three (3.3%) and late dislocation in 16 (17.8%). Infection was found in nine hips (10.0%).

At operation, a range of changes was noted including cavities containing cloudy fluid under pressure, necrotic soft tissues with avulsed tendons and denuded osteonecrotic upper femora. Corrosion was frequently observed on the retrieved cemented part of the femoral component. Typically, the peri-operative findings confirmed those found on pre-operative metal artefact reduction sequence MRI and histological examination showed severe necrosis.

Metal artefact reduction sequence MRI proved to be useful when investigating these patients with pain in the absence of adverse plain radiological features.

Migration of the acetabular component may give rise to oval-shaped bone defects in the acetabulum. The oblong implant is designed to fill these defects and achieve a stable cementless anchorage with no significant bone loss. We prospectively reviewed 133 oblong long oblique revision components at a mean follow-up of 9.74 years (0.6 to 14). All had been used in revisions for defects of type IIB to IIIB according to Paprosky. Aseptic loosening was the reason for revision in 11 cases (8.3%) and deep infection in seven (5.3%). The probability of implant survival over a 12-year follow-up estimated by the Kaplan-Meier method gave a survival rate of 0.85% respectively 0.90% when deep infection was excluded as the endpoint.

Our study supports the use of these components in defects from IIB to IIIA. The main precondition for success is direct contact of more than half of the surface of the implant with the host acetabular bone.

Ensuring the accuracy of the intra-operative orientation of the acetabular component during a total hip replacement can be difficult. In this paper we introduce a reproducible technique using the transverse acetabular ligament to determine the anteversion of the acetabular component. We have found that this ligament can be identified in virtually every hip undergoing primary surgery. We describe an intra-operative grading system for the appearance of the ligament. This technique has been used in 1000 consecutive cases. During a minimum follow-up of eight months the dislocation rate was 0.6%. This confirms our hypothesis that the transverse acetabular ligament can be used to determine the position of the acetabular component. The method has been used in both conventional and minimally-invasive approaches.