Aims. Type 2 diabetes mellitus (T2DM) impairs bone strength and is a significant risk factor for hip fracture, yet currently there is no reliable tool to assess this risk. Most risk stratification methods rely on bone mineral density, which is not impaired by diabetes, rendering current tests ineffective. CT-based finite element analysis (CTFEA) calculates the mechanical response of bone to load and uses the yield strain, which is reduced in T2DM patients, to measure bone strength. The purpose of this
Pre-operative planning for total hip replacement
(THR) is challenging in hips with severe acetabular deformities, including
those with a hypoplastic acetabulum or severe defects and in the
presence of arthrodesis or ankylosis. We evaluated whether a Rapid
Prototype (RP) model, which is a life-sized reproduction based on
three-dimensional CT scans, can determine the
Aims. This paper describes the methodology, validation and reliability
of a new computer-assisted method which uses models of the patient’s
bones and the components to measure their migration and polyethylene
wear from radiographs after total hip arthroplasty (THA). Materials and Methods. Models of the patient’s acetabular and femoral component obtained
from the manufacturer and models of the patient’s pelvis and femur
built from a single computed tomography (CT) scan, are used by a
computer program to measure the migration of the components and
the penetration of the femoral head from anteroposterior and lateral radiographs
taken at follow-up visits. The program simulates the radiographic
setup and matches the position and orientation of the models to
outlines of the pelvis, the acetabular and femoral component, and
femur on radiographs. Changes in position and orientation reflect
the migration of the components and the penetration of the femoral
head. Validation was performed using radiographs of phantoms simulating
known migration and penetration, and the clinical
This study compares the re-revision rate and mortality following septic and aseptic revision hip arthroplasty (rTHA) in registry data, and compares the outcomes to previously reported data. This is an observational cohort study using data from the German Arthroplasty Registry (EPRD). A total of 17,842 rTHAs were included, and the rates and cumulative incidence of hip re-revision and mortality following septic and aseptic rTHA were analyzed with seven-year follow-up. The Kaplan-Meier estimates were used to determine the re-revision rate and cumulative probability of mortality following rTHA.Aims
Methods
The primary aim of this trial was to compare the subsidence of two similar hydroxyapatite-coated titanium femoral components from different manufacturers. Secondary aims were to compare rotational migration (anteversion/retroversion and varus/valgus tilt) and patient-reported outcome measures between both femoral components. Patients were randomized to receive one of the two femoral components (Avenir or Corail) during their primary total hip arthroplasty between August 2018 and September 2020. Radiostereometric analysis examinations at six, 12, and 24 months were used to assess the migration of each implanted femoral component compared to a baseline assessment. Patient-reported outcome measures were also recorded for these same timepoints. Overall, 50 patients were enrolled (62% male (n = 31), with a mean age of 65.7 years (SD 7.3), and mean BMI of 30.2 kg/m2 (SD 5.2)).Aims
Methods
Spinopelvic pathology increases the risk for instability following total hip arthroplasty (THA), yet few studies have evaluated how pathology varies with age or sex. The aims of this study were: 1) to report differences in spinopelvic parameters with advancing age and between the sexes; and 2) to determine variation in the prevalence of THA instability risk factors with advancing age. A multicentre database with preoperative imaging for 15,830 THA patients was reviewed. Spinopelvic parameter measurements were made by experienced engineers, including anterior pelvic plane tilt (APPT), spinopelvic tilt (SPT), sacral slope (SS), lumbar lordosis (LL), and pelvic incidence (PI). Lumbar flexion (LF), sagittal spinal deformity, and hip user index (HUI) were calculated using parameter measurements.Aims
Methods
Aims. Total hip arthroplasty (THA) has well known subjective benefits,
but little is known objectively about the recovery of mobility in
the early post-operative period. Patients and Methods. A total of 33 patients aged >
60 years who underwent elective
primary THA had their activity monitored for 30 days post-operatively
using an at-home (Fitbit) ankle accelerometer. Their mean age was
70.7 years (61 to 86); 15 (45.5%) were female. The rate of compliance
and the mean level of activity were determined. Comparisons between subgroups
based on age, body mass index (BMI), surgical approach, and the
destination of the patients when discharged were also performed. Results. The mean compliance over the 30 days was 26.7 days (16 to 30;
89%) of use. The mean number of steps increased from 235 (5 to 1152)
to 2563 (87 to 7280) (p <
0.001) between the first and the 30th
post-operative day. Age <
70 years and an anterior surgical approach
were significantly associated with higher levels of activity (1600
to 2400 (p = 0.016 to 0.031) and 1000 to 1800 (p = 0.017 to 0.037)
more steps per day, respectively) between the second and the fourth
week post-operatively. There was also a trend towards higher levels
of activity in those who were discharged to their home rather than
to a nursing facility (a mean of 1500 more steps per day, p = 0.02).
BMI greater or less than 30 kg/m. 2. was not predictive
of activity (p = 0.45 to 0.98). Conclusion. At-home remote mobility monitoring using existing commercially
available technology is
It is not known whether preservation of the capsule of the hip positively affects patient-reported outcome measures (PROMs) in total hip arthroplasty using the direct anterior approach (DAA-THA). A recent randomized controlled trial found no clinically significant difference at one year postoperatively. This study aimed to determine whether preservation of the anterolateral capsule and anatomical closure improve the outcome and revision rate, when compared with resection of the anterolateral capsule, at two years postoperatively. Two consecutive groups of patients whose operations were performed by the senior author were compared. The anterolateral capsule was resected in the first group of 430 patients between January 2012 and December 2014, and preserved and anatomically closed in the second group of 450 patients between July 2015 and December 2017. There were no other technical changes between the two groups. Patient characteristics, the Charlson Comorbidity Index (CCI), and surgical data were collected from our database. PROM questionnaires, consisting of the Oxford Hip Score (OHS) and Core Outcome Measures Index (COMI-Hip), were collected two years postoperatively. Data were analyzed with generalized multiple regression analysis.Aims
Methods
Periprosthetic joint infections (PJIs) with prior multiple failed surgery for reinfection represent a huge challenge for surgeons because of poor vascular supply and biofilm formation. This study aims to determine the results of single-stage revision using intra-articular antibiotic infusion in treating this condition. A retrospective analysis included 78 PJI patients (29 hips; 49 knees) who had undergone multiple prior surgical interventions. Our cohort was treated with single-stage revision using a supplementary intra-articular antibiotic infusion. Of these 78 patients, 59 had undergone more than two prior failed debridement and implant retentions, 12 patients had a failed arthroplasty resection, three hips had previously undergone failed two-stage revision, and four had a failed one-stage revision before their single-stage revision. Previous failure was defined as infection recurrence requiring surgical intervention. Besides intravenous pathogen-sensitive agents, an intra-articular infusion of vancomycin, imipenem, or voriconazole was performed postoperatively. The antibiotic solution was soaked into the joint for 24 hours for a mean of 16 days (12 to 21), then extracted before next injection. Recurrence of infection and clinical outcomes were evaluated.Aims
Methods
The aims of this study were to develop an in vivo model of periprosthetic joint infection (PJI) in cemented hip hemiarthroplasty, and to monitor infection and biofilm formation in real-time. Sprague-Dawley rats underwent cemented hip hemiarthroplasty via the posterior approach with pre- and postoperative gait assessments. Infection with Aims
Methods
The purpose of this study was to determine the access to and ability to use telemedicine technology in adult patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), and to determine associations with the socioeconomic characteristics of the patients, including age, sex, race, and education. We also sought to understand the patients’ perceived benefits, risks, and preferences when dealing with telemedicine. We performed a cross-sectional survey involving patients awaiting primary THA and TKA by one of six surgeons at a single academic institution. Patients were included and called for a telephone-administered survey if their surgery was scheduled to be between 23 March and 2 June 2020, and were aged > 18 years.Aims
Methods
Modular dual mobility (MDM) acetabular components are often used with the aim of reducing the risk of dislocation in revision total hip arthroplasty (THA). There is, however, little information in the literature about its use in this context. The aim of this study, therefore, was to evaluate the outcomes in a cohort of patients in whom MDM components were used at revision THA, with a mean follow-up of more than five years. Using the database of
a single academic centre, 126 revision THAs in 117 patients using a single
design of an MDM acetabular component were retrospectively reviewed. A total of 94 revision THAs in 88 patients with a mean follow-up of 5.5 years were included in the study. Survivorship was analyzed with the endpoints of dislocation, reoperation for dislocation, acetabular revision for aseptic loosening, and acetabular revision for any reason. The secondary endpoints were surgical complications and the radiological outcome.Aims
Methods
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. A total of 355 patients (400 hips) were treated with Conserve Plus HRA between November 1996 and November 2000. There were 96 female (27%) and 259 male patients (73%). Their mean age was 48.2 years (SD 10.9). The University of California, Los Angeles (UCLA) hip scores and 12-item Short Form Survey (SF-12) quality of life scores were reported. Survivorship was assessed using Kaplan-Meier analyses.Aims
Methods
Restoration of leg length and offset is an important
goal in total hip replacement. This paper reports a calliper-based technique
to help achieve these goals by restoring the location of the centre
of the femoral head. This was validated first by using a co-ordinate
measuring machine to see how closely the calliper technique could
record and restore the centre of the femoral head when simulating
hip replacement on Sawbone femur, and secondly by using CT in patients
undergoing hip replacement. Results from the co-ordinate measuring machine showed that the
centre of the femoral head was predicted by the calliper to within
4.3 mm for offset (mean 1.6 (95% confidence interval (CI) 0.4 to
2.8)) and 2.4 mm for vertical height (mean -0.6 (95% CI -1.4 to
0.2)).
The CT scans showed that offset and vertical height were restored
to within 8 mm
(mean -1 (95% CI -2.1 to 0.6)) and -14 mm (mean 4 (95% CI 1.8 to
4.3)), respectively. Accurate assessment and restoration of the centre of the femoral
head is
Periprosthetic fractures (PPFs) around cemented taper-slip femoral prostheses often result in a femoral component that is loose at the prosthesis-cement interface, but where the cement-bone interface remains well-fixed and bone stock is good. We aim to understand how best to classify and manage these fractures by using a modification of the Vancouver classification. We reviewed 87 PPFs. Each was a first episode of fracture around a cemented femoral component, where surgical management consisted of revision surgery. Data regarding initial injury, intraoperative findings, and management were prospectively collected. Patient records and serial radiographs were reviewed to determine fracture classification, whether the bone cement was well fixed (B2W) or loose (B2L), and time to fracture union following treatment.Aims
Methods
Peri- and sub-prosthetic fractures, or pathological fractures below an existing well-fixed femoral component, with or without an ipsilateral knee replacement, present a difficult surgical challenge. We describe a simple solution, in which a custom-made prosthesis with a cylindrical design is cemented proximally to the stem of an existing, well-fixed femoral component. This effectively treats the fracture without sacrificing the good hip. We describe five patients with a mean age of 73 years (60 to 81) and a mean follow-up of 47 months (6 to 108). The mean overlap of the prosthesis over the femoral component was 7.5 cm (5.5 to 10). There have been no mechanical failures, no new infections and no re-operations. We suggest that in highly selected cases, in which conventional fixation is not
The most frequent indication for revision surgery in total hip arthroplasty (THA) is aseptic loosening. Aseptic loosening is associated with polyethylene liner wear, and wear may be reduced by using vitamin E-doped liners. The primary objective of this study was to compare proximal femoral head penetration into the liner between a) two cross-linked polyethylene (XLPE) liners (vitamin E-doped (vE-PE)) versus standard XLPE liners, and b) two modular femoral head diameters (32 mm and 36 mm). Patients scheduled for a THA were randomized to receive a vE-PE or XLPE liner with a 32 mm or 36 mm metal head (four intervention groups in a 2 × 2 factorial design). Head penetration and acetabular component migration were measured using radiostereometric analysis at baseline, three, 12, 24, and 60 months postoperatively. The Harris Hip Score, University of California, Los Angeles (UCLA) Activity Score, EuroQol five-dimension questionnaire (EQ-5D), and 36-Item Short-Form Health Survey questionnaire (SF-36) were assessed at baseline, three, 12, 36, and 60 months.Aims
Methods
The aim of this study was to develop a novel computational model for estimating head/stem taper mechanics during different simulated assembly conditions. Finite element models of generic cobalt-chromium (CoCr) heads on a titanium stem taper were developed and driven using dynamic assembly loads collected from clinicians. To verify contact mechanics at the taper interface, comparisons of deformed microgroove characteristics (height and width of microgrooves) were made between model estimates with those measured from five retrieved implants. Additionally, these models were used to assess the role of assembly technique—one-hit versus three-hits—on the taper interlock mechanical behaviour.Aims
Methods
The aim of this study was to report our experience at 3.5 years with outpatient total hip arthroplasty (THA). In this prospective cohort study, we included all patients who were planned to receive primary THA through the anterior approach between 1 April 2014 and 1 October 2017. Patient-related data and surgical information were recorded. Patient reported outcome measures (PROMs) related to the hip and an anchor question were taken preoperatively, at six weeks, three months, and one year after surgery. All complications, readmissions, and reoperations were registered.Aims
Methods
Vancouver type B periprosthetic femoral fractures (PFF) are challenging complications after total hip arthroplasty (THA), and some treatment controversies remain. The objectives of this study were: to evaluate the short-to-mid-term clinical outcomes after treatment of Vancouver type B PFF and to compare postoperative outcome in subgroups according to classifications and treatments; to report the clinical outcomes after conservative treatment; and to identify risk factors for postoperative complications in Vancouver type B PFF. A total of 97 consecutive PPFs (49 males and 48 females) were included with a mean age of 66 years (standard deviation (SD) 14.9). Of these, 86 patients were treated with surgery and 11 were treated conservatively. All living patients had a minimum two-year follow-up. Patient demographics details, fracture healing, functional scores, and complications were assessed. Clinical outcomes between internal fixation and revisions in patients with or without a stable femoral component were compared. Conservatively treated PPFs were evaluated in terms of mortality and healing status. A logistic regression analysis was performed to identify risk factors for complications.Aims
Methods
