Introduction. The anatomic dual mobility (ADM) technology utilized a monoblock cobalt chromium acetabular component. However, design limitations conferred difficulties controlling orientation during component insertion and inability to confirm full implant seating; the solution resulted in the creation of the modular dual mobility (MDM). The modular implant combines a standard titanium acetabular component and a cobalt chromium liner insert. Due to the metal-on-metal interface on MDM implants, fretting and corrosion releasing metal ions like previous metal-on-metal THA implants, were a concern. This study prospectively reviewed metal ions (cobalt, chromium and titanium) on patients who were at least 1 year post MDM implantation and compared them to patients with an ADM implant and evaluated radiographic seating of the components. Methods. All patients with ADM and MDM implants underwent evaluation of metal ions (cobalt, chromium and titanium) at their one year follow-up appointment. Radiographic evaluation for acetabular polar gaps was performed. Elevated metal ions were determined using standard laboratory ranges.
It is important to analyze objectively the hammering sound in cup press-fit technique in total hip arthroplasty (THA) in order to better understand the change of the sound during impaction. We hypothesized that a specific characteristic would present in a hammering sound with successful fixation. We designed the study to quantitatively investigate the acoustic characteristics during cementless cup impaction in THA. In 52 THAs performed between November 2018 and April 2022, the acoustic parameters of the hammering sound of 224 impacts of successful press-fit fixation, and 55 impacts of unsuccessful press-fit fixation, were analyzed. The successful fixation was defined if the following two criteria were met: 1) intraoperatively, the stability of the cup was retained after manual application of the torque test; and 2) at one month postoperatively, the cup showed no translation on radiograph. Each hammering sound was converted to sound pressures in 24 frequency bands by fast Fourier transform analysis. Basic patient characteristics were assessed as potential contributors to the hammering sound.Aims
Methods
It is important to analyze objectively the hammering sound in cup press-fit technique in total hip arthroplasty (THA) in order to better understand the change of the sound during impaction. We hypothesized that a specific characteristic would present in a hammering sound with successful fixation. We designed the study to quantitatively investigate the acoustic characteristics during cementless cup impaction in THA. In 52 THAs performed between November 2018 and April 2022, the acoustic parameters of the hammering sound of 224 impacts of successful press-fit fixation, and 55 impacts of unsuccessful press-fit fixation, were analyzed. The successful fixation was defined if the following two criteria were met: 1) intraoperatively, the stability of the cup was retained after manual application of the torque test; and 2) at one month postoperatively, the cup showed no translation on radiograph. Each hammering sound was converted to sound pressures in 24 frequency bands by fast Fourier transform analysis. Basic patient characteristics were assessed as potential contributors to the hammering sound.Aims
Methods
Introduction. Uncertainties in the management of patients with MOM hip implants continue to be a problem for all surgeons. Guidelines vary and do not fully define or quantify thresholds. We aimed to assess the differences in decision-making amongst an international community of six specialist orthopaedic institutions. Methods. Five international tertiary referral orthopaedic units (one UK, two USA, and two European) were invited to participate. Each unit organised an MDT panel consisting of 2 or more hip surgeons and a musculoskeletal radiologist. All units discussed the same 10 patients. A full clinical dataset was provided including blood test and all imaging.
This study investigates the use of the Metabolic Equivalent of Task (MET) score in a hip arthroplasty population and its ability to capture additional benefit beyond the maximum Oxford Hip Score (OHS). OHS, EuroQol-5D index (EQ-5D), and the MET were prospectively recorded in 221 primary hip arthroplasty procedures pre-operatively and at 1-year. The distribution was examined reporting the presence of ceiling & floor effects. Validity was assessed correlating the MET with the other scores using Spearman's rank and determining responsiveness using the standardised response mean (SRM). A subgroup of 93 patients scoring 48/48 on the OHS were analysed by age group, sex, BMI and pre-operative MET using the other two metrics to determine if differences could be established despite all scoring identically on the OHS. 117 total hip and 104 hip resurfacing arthroplasty operations were included. Mean age was 59.4 ± 11.3. Post-operatively the OHS and EQ-5D demonstrate significant negatively skewed distributions with ceiling effects of 41% and 53%, respectively. The MET was normally distributed post-operatively with no ceiling effect. Weak-moderate but statistically significant correlations were found between the MET and the other two metrics both pre & post-operatively. Responsiveness was excellent, SRM for OHS: 2.01, EQ-5D: 1.06 and MET: 1.17. In the 48/48 scoring subgroup, no differences were found comparing groups with the EQ-5D, however significantly higher MET scores were demonstrated for patients aged <60 (12.7 vs 10.6, p=0.008), male patients (12.5 vs 10.8, p=0.024) and those with pre-operative MET scores >6 (12.6 vs 11.0, p=0.040). The MET is normally distributed in patients following hip arthroplasty, recording levels of activity which are undetectable using the OHS. As a simple, valid activity metric, it should be considered in addition to conventional PROMs in order to capture the entire benefit experienced following hip arthroplasty.
The aims of the study were to determine the differences in spinopelvic mobility between a cohort of hip OA patients and a control group for the 1) standing to relaxed-seated and 2) standing to deep-seated task. A cohort of 40 patients with end-stage hip OA and a control group of 40 subjects, matched for age, gender and BMI were prospectively studied. Clinical data and lateral view radiographs in different positions were assessed. Sagittal spinopelvic mobility was calculated as the change when moving from the standing to relaxed-seated and standing to deep-seated positions for the lumbar lordosis angle, pelvic tilt and pelvic-femoral angle.Aims
Methods
Modern metal-on-metal bearings produce less wear debris and osteolysis, but have the potential adverse effect of release of ions. Improved ceramic-on-ceramic bearings have the lowest wear of all, but the corrosion process has not been analysed. Our aim was to measure the serum ion release (ng/ml) in 23 patients having stable hip prostheses with a ceramic-on-ceramic coupling (group A) and to compare it with the release in 42 patients with a metal-on-metal bearing (group B) in the medium term. Reference values were obtained from a population of 47 healthy subjects (group C). The concentrations of chromium, cobalt, aluminium and titanium were measured. There was a significant increase of cobalt, chromium and aluminium levels (p <
0.05) in group B compared with groups A and C. Group A did not differ significantly from the control group. Despite the apparent advantage of a metal-on-metal coupling, especially in younger patients with a long life expectancy, a major concern arises regarding the extent and duration of ion exposure. For this reason, the low corrosion level in a ceramic-on-ceramic coupling could be advantageous.
We investigated differences in the location and
mode of labral tears between dysplastic hips and hips with femoroacetabular
impingement (FAI). We also investigated the relationship between
labral tear and adjacent cartilage damage. We retrospectively studied
72 symptomatic hips (in 68 patients: 19 men and 49 women) with radiological
evidence of dysplasia or FAI on high-resolution CT arthrography.
The incidence and location of labral tears and modes of tear associated
with the base of the labrum (Mode 1) or body of the labrum (Mode
2) were compared among FAI, mildly dysplastic and severely dysplastic
hips. The locations predominantly involved with labral tears were
different in FAI and mild dysplastic hips (anterior and anterosuperior
zones) and in severely dysplastic hips (anterosuperior and superior
zones) around the acetabulum. Significant differences were observed
in the prevalence of Mode 1 Hip pathology is significantly related to the locations and modes
of labral tears. Mode 1 tears may be a risk factor for the development
of adjacent acetabular cartilage damage. Cite this article:
Obesity is known to influence surgical risk in total hip replacement (THR), with increased Body Mass Index (BMI) leading to elevated risk of complications and poorer outcome scores. Using a multinational trial data of a single implant, we assess the impact of BMI and regional variations on Harris Hip scores (HHS). We assessed BMI in 11 regional centres and associations with HHS at one year. Data were collected from 744 patients prospectively from 11 centres in the UK, Germany, Switzerland, Austria, New Zealand and Netherlands as part of a multicentre outcome trial. All Arthroplasties used RM Pressfit vitamys components (Mathys, Switzerland). Demographic, operative data and HHS were analysed with General Linear Model Anova, Minitab 16 (Minitab Inc, Pennsylvania).Introduction
Method
Aims. To evaluate how abnormal proximal femoral anatomy affects different femoral version measurements in young patients with hip pain. Methods. First, femoral version was measured in 50 hips of symptomatic consecutively selected patients with hip pain (mean age 20 years (SD 6), 60% (n = 25) females) on preoperative CT scans using different measurement methods: Lee et al, Reikerås et al, Tomczak et al, and Murphy et al. Neck-shaft angle (NSA) and α angle were measured on coronal and radial CT images. Second, CT scans from three patients with femoral retroversion, normal femoral version, and anteversion were used to create 3D femur models, which were manipulated to generate models with different NSAs and different cam lesions, resulting in eight models per patient. Femoral version measurements were repeated on manipulated femora. Results. Comparing the different measurement methods for femoral version resulted in a maximum mean difference of 18° (95% CI 16 to 20) between the most proximal (Lee et al) and most distal (Murphy et al) methods. Higher differences in proximal and distal femoral version measurement techniques were seen in femora with greater femoral version (r > 0.46; p < 0.001) and greater NSA (r > 0.37; p = 0.008) between all measurement methods. In the parametric 3D manipulation analysis, differences in femoral version increased 11° and 9° in patients with high and normal femoral version, respectively, with increasing NSA (110° to 150°). Conclusion. Measurement of femoral version angles differ depending on the method used to almost 20°, which is in the range of the aimed surgical correction in derotational femoral osteotomy and thus can be considered clinically relevant.
Recently, some smart media devices including portable accelerometers have been used to measure objective physical activity (OPA) after total hip arthroplasty (THA). The aim of this study was to longitudinally assess OPA changes in patients who underwent THA using a compact triaxial accelerometer and to investigate the impact of this recovery process on patient-reported outcomes. This prospective cohort study involved 163 consecutive patients who had unilateral osteoarthritis of the hip and were followed up for 12 months after THA. There were 132 women and 31 men with average age of 66 years. OPA was measured using a compact triaxial accelerometer preoperatively and at 1, 3, 6, and 12 months postoperatively. This study investigated the recovery process of OPA in four patient groups classified by the median of age and preoperative activity levels (younger and higher activity (YH), younger and lower activity (YL), older and higher activity (OH), and older and lower activity (OL)), and examined its impact on patient-reported outcomes, including forgotten joint score-12 (FJS-12). The target period for regaining preoperative activity levels was approximately 3 months for patients with lower preoperative activity, and about 6 months for those with higher preoperative activity. The OPA at 12 months postoperatively was higher in the patients with higher preoperative activity levels than in those with lower preoperative activity levels. In patients with higher preoperative activity levels, FJS-12 scores significantly increased between 6 and 12 months postoperatively (p=0.018). FJS-12 at 12 months postoperatively was best in YH (81.7±18.9), followed by YL (73.5±22.9), OH (73.2±17.4), and OL (66.3±21.8).
The interest in day-case hip arthroplasty is increasing; however, there are conflicting results regarding readmission risk, and little is known about patients’ attitude towards day-case surgery. We aimed to investigate differences in 30-day readmission rates between day-case patients and single-overnight-stay patients following total hip arthroplasty (THA) and explore patients’ attitude towards day-case surgery. From the Danish National Patient Register we identified 29,486 THAs (1353 day-case THAs and 28,133 single-overnight-stay THAs) performed between 2010 and 2020. Day-case surgery was defined as discharge on the day-of-surgery. Overnight admissions within 30 days of surgery were considered readmissions.
The Norwegian Arthroplasty Register (NAR) started collecting data on total hip arthroplasty (THA) in 1987. Very long-term results of implants for THA are scarce. We aimed to show long-term results for the three most used femoral stems, operated from 1987. We included the uncemented Corail femoral stem (n=66,309) and the cemented Exeter stem (n=35,050) both of which are currently in frequent use. In addition, we included the Charnley stem (n=32,578, in use until 2014). To ensure comparable conditions, stems fixated with low viscosity cement and stems revised due to infections were excluded.
In 1997 the Birmingham Hip Resurfacing was introduced to address the needs of young active patients. Alternative designs were introduced to try and improve wear performance. The aim of this study was a comparative cohort study of two types of metal-on-metal bearing to determine the mechanism of failure at 15 years. The study reviewed 91 Brimingham Hip Resurfacings (BHR) (Smith and Nephew) and 715 DUROM hip resurfacing (Zimmer) procedures in prior to 2009. Failure was defined as revision of either component for any reason. Kaplan-Meyer survivorship analysis performed. Routine follow-up with serum metal ion levels and radiographs. Mean follow-up was 17.9 years (range 15.2 – 25.1). The mean age at operation was 51.6 years (SD 8.6, range 20.7 to 70.2), including 299 women (37.1%). The Birmingham resurfacing demonstrated 92.3% survivorship at 15 years (SE 2.8, 95% CI 3.9 – 7.8) and 90.0% at latest follow-up (SE 3.5, 95% CI 4.9 to 9.4). By comparison, the DUROM survivorship at 15 years was 89.1% at 15 years (SE 1.2, 95% CI 2.0 to 2.5) and 87.4% (SE 1.3, 95% CI 2.5 to 2.3) at latest follow-up. There was no statistically significant difference in survivorship between groups (p= 0.32). Survival in male patients was 92.7% compared to 80.0% in females. The reported failures occurred from Adverse Reaction to Metal Debris (32 patients), periprosthetic femoral neck fracture (6) and aseptic loosening (41), PJI (12) and undiagnosed pain (6). The mean cobalt and chromium levels at last follow-up were 33.4 nmol/L and 36.5 nmol/L respectively. This study demonstrates two differently designed metal-on-metal hip resurfacing provided a durable alternative to total hip replacement, particularly in younger male patients with osteoarthritis.
Appropriate surgical management of hip fractures has major clinical and economic consequences. Recently IMN use has increased compared to SHS constructs, despite no clear evidence demonstrating superiority of outcome. We therefore set out to provide further evidence about the clinical and economic implications of implant choice when considering hip fracture fixation strategies. A retrospective cohort study using Scottish hip fracture audit (SHFA) data was performed for the period 2016–2022. Patients ≥50 with a hip fracture and treated with IMN or SHS constructs at Scottish Hospitals were included. Comparative analyses, including adjustment for confounders, were performed utilising Multivariable logistic regression for dichotomous outcomes and Mann-Whitney-U tests for non-parametric data. A sub-group analysis was also performed focusing on AO-A1/A2 configurations which utilised additional regional data. Cost differences in Length of Stay (LOS) were calculated using defined costs from the NHS Scotland Costs book. In all analyses p<0.05 denoted significance. 13638 records were included (72% female). 9867 received a SHS (72%). No significant differences were identified in 30 or 60-day survival (Odds Ratio [OR] 1.05, 95%CI 0.90–1.23; p=0.532), (OR 1.10, 95%CI 0.97–1.24; p=0.138) between SHS and IMN's. There was however a significantly lower early mobilisation rate with IMN vs SHS (OR 0.64, 95%CI 0.59–0.70; p<0.001), and lower likelihood of discharge to domicile by day-30 post-admission (OR 0.77, 95%CI 0.71–0.84; p<0.001). Acute and overall, LOS were significantly lower for SHS vs IMN (11 vs 12 days and 20 vs 24 days respectively; p<0.001). Findings were similar across a sub-group analysis of 559 AO A1/A2 fracture configurations.
Aims. Cross-table lateral (CTL) radiographs are commonly used to measure acetabular component anteversion after total hip arthroplasty (THA). The CTL measurements may differ by > 10° from CT scan measurements but the reasons for this discrepancy are poorly understood. Anteversion measurements from CTL radiographs and CT scans are compared to identify spinopelvic parameters predictive of inaccuracy. Methods. THA patients (n = 47; 27 males, 20 females; mean age 62.9 years (SD 6.95)) with preoperative spinopelvic mobility, radiological analysis, and postoperative CT scans were retrospectively reviewed. Acetabular component anteversion was measured on postoperative CTL radiographs and CT scans using 3D reconstructions of the pelvis. Two cohorts were identified based on a CTL-CT error of ≥ 10° (n = 11) or < 10° (n = 36). Spinopelvic mobility parameters were compared using independent-samples t-tests. Correlation between error and mobility parameters were assessed with Pearson’s coefficient. Results. Patients with CTL error > 10° (10° to 14°) had stiffer lumbar spines with less mean lumbar flexion (38.9°(SD 11.6°) vs 47.4° (SD 13.1°); p = 0.030), different sagittal balance measured by pelvic incidence-lumbar lordosis mismatch (5.9° (SD 18.8°) vs -1.7° (SD 9.8°); p = 0.042), more pelvic extension when seated (pelvic tilt -9.7° (SD 14.1°) vs -2.2° (SD 13.2°); p = 0.050), and greater change in pelvic tilt between supine and seated positions (12.6° (SD 12.1°) vs 4.7° (SD 12.5°); p = 0.036). The CTL measurement error showed a positive correlation with increased CTL anteversion (r = 0.5; p = 0.001), standing lordosis (r = 0.23; p = 0.050), seated lordosis (r = 0.4; p = 0.009), and pelvic tilt change between supine and step-up positions (r = 0.34; p = 0.010). Conclusion.
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. Patients and Methods. A total of 89 patients were enrolled into a prospective study. All patients received a PTC shell and were randomized to receive a VEPE liner (n = 44) or a moderately crosslinked polyethylene (ModXLPE) liner (n = 45). Radiostereometric analysis (RSA) was used to measure polyethylene wear and component migration.
Introduction. Cross table lateral (CTL) radiographs are commonly used to measure acetabular component anteversion after total hip arthroplasty (THA). CTL measurements may differ by >10 degrees from CT scan measurements, but the reasons for this discrepancy are poorly understood. We compare anteversion measurements made on CTL radiographs and CT scans to identify spinopelvic parameters predictive of inaccuracy. Methods. THA patients (n=47) with preoperative spinopelvic radiographic analysis and postoperative CT scans were retrospectively reviewed. Acetabular component anteversion was measured on post-operative CTL radiographs, and CT scans using 3D reconstructions of the pelvis. Patients were grouped by error (CTL-CT)>10° (n=11) or <10° (n=36), and spinopelvic mobility parameters were compared using t-tests. Correlation between error and mobility parameters was assessed with Pearson coefficient. Results. Patients with CTL error >10° (range 10–14) had stiffer lumbar spines with less lumbar flexion (38° vs 47°, p=0.03), greater sagittal imbalance measured by pelvic incidence-lumbar lordosis mismatch (6° vs −2°, p=0.04), more pelvic extension when seated (pelvic tilt −10° vs −2°, p=0.05), and greater change in pelvic tilt between supine and seated positions (13° vs 4°, p=0.04). The error of CTL measurements showed a positive correlation with increased CTL anteversion (r=0.5, p=0.001), standing lordosis (r=0.23, p=0.05), seated lordosis (r=0.4, p=0.01) and pelvic tilt change between supine and step-up positions (r=0.34, p=0.01). Discussion.
Clinical decision-making is often based on evidence of outcome after a specific treatment. Surgeons and patients may, have different perceptions and expectations of what to achieve following a Total Hip Replacement (THR). Several studies have shown that unfulfilled expectations are a principal source of patient dissatisfaction and patients are typically overly optimistic with regards to expected outcomes following surgery. Published data on clinical and functional outcomes show that persistence of symptoms, such as pain, and failure to return to preoperative levels of function are normal. To measure patient's expectations we undertook prospective study reviewing patients' expectations in 1800 THRs over a 21-year period (1997–2018). Of the whole cohort, 48.98% patients reported they wanted a THR to overcome unbearable pain. 11.75 % wanted a THR to be able to walk without a limp. 9.69% wanted to a THR to increase walk endurance. 61.97% reported it was extremely important to decrease pain following a THR. In 2001, the most important reason for a THR reported by patients was to relieve unbearable pain and this remained the same most important reason in 2018. This result was also statistically significant with a p-value of 0.001. 80.36% reported they anticipated ‘no pain’ after recovery from a THR, 16.75% reported they anticipated ‘some pain’ and 2.89% reported they anticipated ‘extreme pain’ following a THR. 74.71% reported it was extremely important to increase their ability to undertake normal activities. 22.06% reported it was very important, 2.40% reported it was moderately important, 0.55% slightly important and 0.28% reported it was not all to important to increase their ability to undertake normal activity. In conclusion patients' want to reduce their pain, walk normally and increase their level activities.
Aims. We investigated patient characteristics and outcomes of Vancouver type B periprosthetic fractures treated with femoral component revision and/or osteosynthesis. Patients and Methods. The study utilized data from the Swedish Hip Arthroplasty Register (SHAR) and information from patient records. We included all primary total hip arthroplasties (THAs) performed in Sweden since 1979, and undergoing further surgery due to Vancouver type B periprosthetic femoral fracture between 2001 and 2011. The primary outcome measure was any further reoperation between 2001 and 2013. Cross-referencing with the National Patient Register was performed in two stages, in order to identify all surgical procedures not recorded on the SHAR. Results. Out of 1381 Vancouver type B fractures that fulfilled the inclusion criteria, 257 underwent further reoperation by the end of 2013. Interprosthetic and Type B1 fractures had a higher risk for reoperation. For B1 fractures, the rate of reoperation did not differ (p = 0.322) after use of conventional (26%) or locking plate osteosynthesis (19%). No significant differences were observed between cemented, cementless monoblock, and cementless modular revision components for the treatment of type B2 and B3 fractures. Conclusion. In this country-specific study, the choice of locking or conventional plates for the treatment of type B1, and cemented or cementless femoral components fixation for B2 and B3 fractures, had no significant influence on risk for reoperation. Interprosthetic fractures adversely affected the outcome of treatment of type B fractures.
