Aims. The aim of this study was to assess the clinical and radiological results of patients who were revised using a custom-made triflange acetabular component (CTAC) for component loosening and pelvic discontinuity (PD) after previous total hip arthroplasty (THA). Methods. Data were extracted from a single centre prospective database of patients with PD who were treated with a CTAC. Patients were included if they had a follow-up of two years. The Hip Disability and Osteoarthritis Outcome Score (HOOS), modified Oxford Hip Score (mOHS), EurQol EuroQoL five-dimension three-level (EQ-5D-3L) utility, and Numeric Rating Scale (NRS), including visual analogue score (VAS) for pain, were gathered at baseline, and at one- and two-year follow-up. Reasons for revision, and radiological and clinical complications were registered. Trends over time are described and tested for significance and clinical relevance. Results. A total of 18 females with 22 CTACs who had a mean age of 73.5 years (SD 7.7) were included. A significant improvement was found in HOOS (p < 0.0001), mOHS (p < 0.0001), EQ-5D-3L utility (p = 0.003), EQ-5D-3L NRS (p = 0.013), VAS pain rest (p = 0.008), and VAS pain activity (p < 0.0001) between baseline and final follow-up. Minimal clinically important improvement in mOHS and the HOOS Physical Function Short Form (HOOS-PS) was observed in 16 patients (73%) and 14 patients (64%), respectively. Definite healing of the PD was observed in 19 hips (86%). Complications included six cases with broken screws (27%), four cases (18%) with bony fractures, and one case (4.5%) with sciatic nerve paresthesia. One patient with concurrent bilateral PD had revision surgery due to recurrent dislocations. No revision surgery was performed for screw failure or implant breakage. Conclusion. CTAC in patients with THA acetabular loosening and PD can result in stable constructs and significant improvement in functioning and health-related quality of life at two years' follow-up. Further follow-up is necessary to determine the mid- to long-term outcome. Cite this article: Bone Jt Open 2023;4(2):53–61

The objective of this study was to assess the clinical and radiological results of patients who were revised using a new generation custom-made triflange acetabular component (CTAC) for component loosening and large acetabular defect (Paprosky 3A and 3B) after previous total hip arthroplasty (THA). New generation CTACs involve the use of patient-specific drill guides and incorporate three-dimensional printed bone models, enhancing precision during surgical implantation. Data were extracted from a single centre prospective database of patients with large acetabular defects who were treated with a new generation CTAC. Patients were included if they had a minimum follow-up of five years. The modified Oxford Hip Score (mOHS), EurQol EuroQoL five-dimension three-level (EQ-5D-3L) utility, and Numeric Rating Scale (NRS), including visual analogue score (VAS) for pain, were gathered at baseline, and at two- and five-year follow-up. Reasons for revision, and radiological and clinical complications were registered. Trends over time are described and tested for significance (p<0.05). A total of 49 (70%) of 70 patients with a mean age of 73.5 years (SD 7.7) had a complete follow-up of 5 years. A significant improvement was found in HOOS, mOHS, EQ-5D-3L utility and NRS, VAS pain rest and activity between baseline and final follow-up. Complications included 8 cases with loosening screws, 4 with bony fractures, 4 periprosthetic infections and 2 cases with dislocation. One patient with bilateral pelvic discontinuity had revision surgery due to recurrent dislocations. No revision surgery was performed for screw failure or implant breakage. New generation CTAC in patients with THA acetabular loosening and massive acetabular bone loss (Paprosky 3A and 3B) can result in stable constructs and significant improvement in functioning and health-related quality of life at five years’ follow-up

Aims. Adverse spinal motion or balance (spine mobility) and adverse pelvic mobility, in combination, are often referred to as adverse spinopelvic mobility (SPM). A stiff lumbar spine, large posterior standing pelvic tilt, and severe sagittal spinal deformity have been identified as risk factors for increased hip instability. Adverse SPM can create functional malposition of the acetabular components and hence is an instability risk. Adverse pelvic mobility is often, but not always, associated with abnormal spinal motion parameters. Dislocation rates for dual-mobility articulations (DMAs) have been reported to be between 0% and 1.1%. The aim of this study was to determine the early survivorship from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) of patients with adverse SPM who received a DMA. Methods. A multicentre study was performed using data from 227 patients undergoing primary total hip arthroplasty (THA), enrolled consecutively. All the patients who had one or more adverse spine or pelvic mobility parameter had a DMA inserted at the time of their surgery. The mean age was 76 years (22 to 93) and 63% were female (n = 145). At a mean of 14 months (5 to 31) postoperatively, the AOANJRR was analyzed for follow-up information. Reasons for revision and types of revision were identified. Results. The AOANJRR reported two revisions: one due to infection, and the second due to femoral component loosening. No revisions for dislocation were reported. One patient died with the prosthesis in situ. Kaplan-Meier survival rate was 99.1% (95% confidence interval 98.3 to 100) at 14 months (number at risk 104). Conclusion. In our cohort of patients undergoing primary THA with one or more factor associated with adverse SPM, DM bearings conferred stability at two years’ follow-up. Cite this article: Bone Joint J 2022;104-B(7):820–825

Adverse spinopelvic mobility (SPM) has been shown to increase risk of dislocation of primary total hip arthroplasty (THA). In patients undergoing THA, prevalence of adverse SPM has been shown to be as high as 41%. Stiff lumbar spine, large posterior standing pelvic tilt and severe sagittal spinal deformity have been identified as risk factors for increased hip instability. Dislocation rates for dual mobility articulations have been reported to be 0% to 1.1%. The aim of this study was to determine the early survivorship from the Australian National Joint Replacement Registry (AOANJRR) of patients with adverse SPM who received a dual mobility articulation. A multicentre study was performed using data from 229 patients undergoing primary THA, enrolled consecutively. All the patients who had one or more adverse spine or pelvic mobility parameters had a dual mobility articulation inserted at the time of their surgery. Average age was 76 (22 to 93) years and 63% were female. At a mean of 2.1 (1 – 3.3) years post-op, the AOANJRR was analysed for follow-up. Reasons for revision and types of revision were identified. The AOANJRR reported two revisions. One due to infection and the second due to femoral component loosening. No revisions for dislocation were reported. One patient died with the prosthesis in situ. Kaplan Meier survival was 99.3% (CI 98.3% − 100%) at 2 years. DM bearings reduce the risk of dislocation of primary THA in patients with adverse spine and pelvic mobility

Introduction. Three-dimensional (3D) printing of porous titanium implants marks a revolution in orthopaedics, promising enhanced bony fixation whilst maintaining design equivalence with conventionally manufactured components. No retrieval study has investigated differences between implants manufactured using these two methods. Our study was the first to compare these two groups using novel non-destructive methods. Materials and methods. We investigated 16 retrieved acetabular cups divided into ‘3D printed’ (n = 6; Delta TT) and ‘conventional’ (n = 10; Pinnacle Porocoat). The groups were matched for age, time to revision, size and gender (Table 1). Reasons for revision included unexplained pain, aseptic loosening, infection and ARMD. Visual inspection was performed to evaluate tissue attachment. Micro-CT was used to assess clinically relevant morphometric features of the porous structure, such as porosity, depth of the porous layer, pore size and strut thickness. Scanning electron microscopy (SEM) was applied to evaluate the surface morphology. Results. Significant differences (p = 0.0002) were found for all morphometric parameters (Table 2). Microscopic analysis revealed uniform beads over the backside of conventional implants, due to the manufacturing technique (Figure 1a). Conversely, beads of random size were found on 3D printed implants, representing a by-product of the manufacturing process, where some starting powder particles are not completely fused together (Figure 1b). The two groups showed similar tissue attachment (3D printed 76.9 ± 27.1%; conventional 73.8 ± 12.2%; p = 0.2635). Conclusion. This was the first study to analyse retrieved 3D printed orthopaedic implants. Differences were found between these and conventional implants, but both literature and registry data do not suggest a short-mid-term clinical issue with 3D printed components. Similar tissue on growth suggested a comparable behaviour with bone in situ. The key difference is the presence of the particles on 3D printed implants, whose clinical significance needs to be investigated. For any figures or tables, please contact the authors directly

Introduction. Historically, US arthroplasty revision rates are based on CMS data that cannot verify initial surgery date in patients under 65 years or laterality of revision. We calculated US one-year revision rates for primary total hip replacement (THR) using a representative cohort. Reasons for revision were documented. Methods. A multi-center cohort from US surgeons in 28 states collected sociodemographic data; medical, emotional, musculoskeletal comorbidities; BMI; and patient-reported pain and function (SF36, HOOS) for elective THR patients. Cases in 2011–2013 were matched with CMS data to ascertain 1 year revision through 2014. Predictors of revision were identified. Chart reviews to verify reasons for revision were performed. Results. Overall, 1.6% of 2926 primary THR surgeries were revised within 12 months. Mean age was 72 years, 59% female. No significant difference in pre-operative age, sex, BMI, pain, function, or emotional health was detected between revision and non-revision patients. Severe low back pain was twice as prevalent among revisions (23% vs. 11%; p<0.04) as was prior stroke (8.5% vs. 3%). Primary reasons for revision were infection (30%), mechanical failure including dislocation (26%), fracture (19%), metal ions (15%) and other (10%). In patients under 65 years of age, the distribution of reasons for revision are identical. Conclusion. The incidence of revision THR in the US within 12 months of the index procedure is 1.6%. Infection and mechanical failure, including dislocation, are the most common causes of early revision, followed by peri-prosthetic fracture. Patients with severe pre-op lumbar spine pain are at higher risk for early revision after THR. Abbreviations: total hip replacement (THR)

Introduction/Aims. The Exeter Stem can be used with metal femoral head that are made of either cobalt chrome, or stainless steel. The aim of this study was to compare the rates of revision of these two metal femoral head types when used with this femoral component. Method. Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) Data from September 1999 until December 2015 for all primary THRs using an Exeter or an Exeter v40 stem with the diagnosis of osteoarthritis were analysed. Only bearing couples that used a metal head with polyethylene were included. The cumulative percent revision (CPR) calculated using Kaplan-Meier estimates were compared for the two metal head types. CPR were further analysed by age, polyethylene type and head size. Reasons for revision and types of revision were assessed. Results. There were 51666 THR that used Exeter or Exeter v40 stems of which 12554 had femoral heads made of cobalt chrome and 39112 had heads made of stainless steel. There was no difference in the rate of revision overall when head types were compared. There was also no difference in CPR between the two head types with age. Hips that used cobalt chrome heads had a higher CPR than stainless steel heads when these were used against non-crosslinked polyethylene. When heads with a diameter of 32mm or greater were compared, those made of cobalt chrome had a higher rate of revision than stainless steel HR 1.38 (1.15, 1.66) P<0.001). Conclusion. There was no difference comparing cobalt chrome or stainless-steel heads, except where non-crosslinked polyethylene was used, or where the heads size was 32mm or greater. In these comparisons, heads made from cobalt chrome had a higher rate of revision

Introduction. Modular-neck hips have twice the rate of revision compared to fixed stems. Metal related pathology is the second most common reason for revision of implants featuring titanium stems with cobalt chrome necks. We aimed to understand the in-vivo performance of current designs and explore the rationale for their continued use. Methods. This study involved the examination of 200 retrieved modular-neck hips grouped according to the material used for their neck and stem. Groups A, B and C had neck/stems featuring CoCr/beta Ti-alloy (TMZF), CoCr/Ti6Al4V-alloy, and Ti6Al4V/Ti6Al4V respectively. Reasons for revision included pain, elevated metal ion levels and fluid collection. The stem-neck interface was assessed for severity of fretting/corrosion using metrology methods to compute linear wear penetration rate. Results. All retrieved implants with a CoCr/Ti combination showed evidence of moderate-severe fretting corrosion at the neck-stem junction. Maximum penetration depth rate in group A (median of 17.9μm/year) was higher than that in group B (median=5.8μm/year); p=0.0012 and group C (median=1.55μm/year), p=0.0095. Implant failure occurred 2-fold earlier in modular-neck hips with TMZF-alloy stems than Ti6Al4V. There was a strong correlation between severity of damage and time to revision in the TMZF group A (p < 0.0001) and between taper damage and Co levels (p < 0.0001) and Cr levels (p < 0.0012). Patient and implant data did not correlate with the amount of material loss observed, (p>0.05). Discussion. The findings are in agreement with registry data as designs with CoCr/Ti at neck/stem interfaces had the highest levels of fretting and corrosion and lower threshold for revision. Conclusion. Corrosion of metal orthopaedic implants remains of clinical concern to patients, surgeons and industry. In light of the findings, the continued use of modular-neck with a metal mismatch at the neck/stem junction is unfavourable and should be avoided

Introduction. We report on the outcome of a cemented flanged acetabular component at a minimum of 10 years post-operatively. Patients/Materials & Methods. Two hundred and three hips were reviewed in 194 consecutive patients who underwent primary total hip arthroplasty using this implant. Cases with acetabular defects requiring bone grafting were excluded. Functional and radiological data were prospectively recorded. Results. Eight hips were revised, 66 hips were implanted in patients who died prior to their 10-year review and 129 hips remain in-situ at a minimum of 10 years. Reasons for revision were periprosthetic fracture due to trauma in 4 cases, recurrent dislocation in 2 cases, infection in 1 case and on-going pain in 1 case (in which infection was suspected but excluded). No hips were revised for aseptic loosening. Oxford and Harris hip scores demonstrated significant clinical improvement. Sixty four percent of the acetabular components were free of lucent lines. In the remainder, the vast majority exhibited lucencies in zone 1 only. Kaplan-Meier survivorship for aseptic loosening was 100% at 12.5 years and for all causes was 97.8% at 12.5 years (95% CI 95.6% – 100%) with 40 cases remaining at risk. Discussion. Data from our study adds further weight to the evidence from joint registries as to the merits of cemented acetabular components in primary THR. Conclusion. The clinical, radiological and survivorship outcomes of this component are excellent

Introduction. Cemented stems have given good results with no difference in outcome when comparing taper slip and composite beam designs in short-term randomised trials. We aimed to ascertain differences in outcome between the different cemented design philosophies using a large-scale registry analysis. Materials and Methods. A retrospective cohort study of National Joint Registry of England and Wales (NJREW) was conducted. The study population included all primary total hip operations performed in the UK from 1 April 2003 to 31 September 2012. All cemented stems were identified and categorised as taper slip (polished) or composite beam (non-polished). Results. Non-polished stems accounted for 16.6% of all primary cemented hip replacements with polished stems making up the remainder. Mean age for non-polished stems was 73.0 years and 71.8 for the polished group (p<0.001) suggesting selection bias. There was a statistically significant increased chance of revision in the non-polished group compared with the polished group (p<0.001). Reasons for revision by fixation type:. Reason for revision. Total. Polished n=253667. Non-polished n=50661. N. %. n. %. Aseptic loosening stem. 532. 300. 0.12. 232. 0.46. Infection. 965. 735. 0.29. 230. 0.45. Stem lysis. 149. 99. 0.04. 50. 0.10. Cup lysis. 156. 125. 0.05. 31. 0.06. Malalignment stem. 114. 86. 0.03. 28. 0.06. The risk of aseptic loosening, stem lysis, malalignment and infection were several magnitudes higher for non-polished stems than for polished varieties (p<0.05). Discussion. Theoretical concerns are reflected in clinical practice with an increased incidence of revision for non-polished stems for all indications recorded. Conclusions. Incidence of revision is higher in cemented non-polished stems compared with polished designs

Aims

The Birmingham Hip Resurfacing (BHR) arthroplasty has been used as a surgical treatment of coxarthrosis since 1997. We present 20-year results of 234 consecutive BHRs performed in our unit.

Aims

The Exeter V40 femoral stem is the most implanted stem in the National Joint Registry (NJR) for primary total hip arthroplasty (THA). In 2004, the 44/00/125 stem was released for use in ‘cement-in-cement’ revision cases. It has, however, been used ‘off-label’ as a primary stem when patient anatomy requires a smaller stem with a 44 mm offset. We aimed to investigate survival of this implant in comparison to others in the range when used in primary THAs recorded in the NJR.

Aims

The aim of our study was to investigate the effect of asymmetric crosslinked polyethylene liner use on the risk of revision of cementless and hybrid total hip arthroplasties (THAs).

Aims

Despite few good-quality studies on the subject, total hip arthroplasty (THA) is increasingly being performed for displaced intracapsular fractures of the neck of femur. We compared outcomes of all patients with displacement of these fractures treated surgically over a ten-year period in one institution.

Aims

The purpose of this study is to examine six types of bearing surfaces implanted at a single institution over three decades to determine whether the reasons for revision vary among the groups and how long it takes to identify differences in survival.

Aims

Femoral revision component subsidence has been identified as predicting early failure in revision hip surgery. This comparative cohort study assessed the potential risk factors of subsidence in two commonly used femoral implant designs.

Objectives

The use of ceramic femoral heads in total hip arthroplasty (THA) has increased due to their proven low bearing wear characteristics. Ceramic femoral heads are also thought to reduce wear and corrosion at the head-stem junction with titanium (Ti) stems when compared with metal heads. We sought to evaluate taper damage of ceramic compared with metal heads when paired with cobalt chromium (CoCr) alloy stems in a single stem design.

Despite excellent results, the use of cemented total hip replacement (THR) is declining. This retrospective cohort study records survival time to revision following primary cemented THR using the most common combination of components that accounted for almost a quarter of all cemented THRs, exploring risk factors independently associated with failure. All patients with osteoarthritis who had an Exeter V40/Contemporary THR (Stryker) implanted before 31 December 2010 and recorded in the National Joint Registry for England and Wales were included in the analysis. Cox’s proportional hazard models were used to analyse the extent to which risk of revision was related to patient, surgeon and implant covariates, with a significance threshold of p < 0.01. A total of 34 721 THRs were included in the study. The overall seven-year rate of revision for any reason was 1.70% (99% confidence interval (CI) 1.28 to 2.12). In the final adjusted model the risk of revision was significantly higher in THRs with the Contemporary hooded component (hazard ratio (HR) 1.88, p < 0.001) than with the flanged version, and in smaller head sizes (< 28 mm) compared with 28 mm diameter heads (HR 1.50, p = 0.005). The seven-year revision rate was 1.16% (99% CI 0.69 to 1.63) with a 28 mm diameter head and flanged component. The overall risk of revision was independent of age, gender, American Society of Anesthesiologists grade, body mass index, surgeon volume, surgical approach, brand of cement/presence of antibiotic, femoral head material (stainless steel/alumina) and stem taper size/offset. However, the risk of revision for dislocation was significantly higher with a ‘plus’ offset head (HR 2.05, p = 0.003) and a hooded acetabular component (HR 2.34, p < 0.001).

In summary, we found that there were significant differences in failure between different designs of acetabular component and sizes of femoral head after adjustment for a range of covariates.

Between 1999 and 2005, 10 264 patients who had undergone total hip replacement (THR) for subcapital fracture of the hip were compared with 76 520 in whom THR had been performed for other reasons. All the cases were identified through the Swedish Hip Arthroplasty Register. The THRs performed as primary treatment for fracture were also compared with those done after failure of internal fixation.

After seven years the rate of revision was higher in THR after fracture (4.4% vs 2.9%). Dislocation and periprosthetic fracture were the most common causes of revision. The risk was higher in men than in women. The type of femoral component and the surgical approach influenced the risk. After correction for gender, type of component and the surgical approach the revision rates were similar in the primary and secondary fracture THR groups.

Total hip replacement is therefore a safe method for both the primary and secondary management of fracture of the hip.

The Norwegian Arthroplasty Register has shown that several designs of uncemented femoral stems give good or excellent survivorship. The overall findings for uncemented total hip replacement however, have been disappointing because of poor results with the use of metal-backed acetabular components. In this study, we exclusively investigated the medium-to long-term performance of primary uncemented metal-backed acetabular components.

A total of 9113 primary uncemented acetabular components were implanted in 7937 patients between 1987 and 2007. These were included in a prospective, population-based observational study. All the implants were modular and metal-backed with ultra-high-molecular-weight polyethylene liners. The femoral heads were made of stainless steel, cobalt-chrome (CoCr) alloy or alumina ceramic. In all, seven different designs of acetabular component were evaluated by the Kaplan-Meier survivorship method and Cox regression analysis.

Most acetabular components performed well up to seven years. When the endpoint was revision of the acetabular component because of aseptic loosening, the survival ranged between 87% and 100% at ten years. However, when the endpoint was revision for any reason, the survival estimates were 81% to 92% for the same implants at ten years. Aseptic loosening, wear, osteolysis and dislocation were the main reasons for the relatively poor overall performance of the acetabular components. Prostheses with alumina heads performed slightly better than those with stainless steel or CoCr alloy in subgroups.

Whereas most acetabular components performed well at seven years, the survivorship declined with longer follow-up. Fixation was generally good. None of the metal-backed uncemented acetabular components with ultra-high-molecular-weight polyethylene liners in our study had satisfactory long-term results because of high rates of wear, osteolysis, aseptic loosening and dislocation.