Aims. The Exeter short stem was designed for patients with Dorr type A
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
Aims. When performing revision total hip arthroplasty using diaphyseal-engaging titanium tapered stems (TTS), the recommended 3 to 4 cm of stem-cortical diaphyseal contact may not be available. In challenging cases such as these with only 2 cm of contact, can sufficient axial stability be achieved and what is the benefit of a prophylactic cable? This study sought to determine, first, whether a prophylactic cable allows for sufficient axial stability when the contact length is 2 cm, and second, if differing TTS taper angles (2° vs 3.5°) impact these results. Methods. A biomechanical matched-pair cadaveric study was designed using six matched pairs of human fresh cadaveric
Periprosthetic hip fractures (PPFs) after total hip arthroplasty are difficult to treat. Therefore, it is important to identify modifiable risk factors such as stem selection to reduce the occurrence of PPFs. This study aimed to clarify differences in fracture torque, surface strain, and fracture type analysis between three different types of cemented stems. We conducted biomechanical testing of bone analogues using six cemented stems of three different types: collarless polished tapered (CPT) stem, Versys Advocate (Versys) stem, and Charnley-Marcel-Kerboull (CMK) stem. Experienced surgeons implanted each of these types of stems into six bone analogues, and the analogues were compressed and internally rotated until failure. Torque to fracture and fracture type were recorded. We also measured surface strain distribution using triaxial rosettes.Aims
Methods
This study aimed to investigate the incidence of ≥ 5 mm asymmetry in lower and whole leg lengths (LLs) in patients with unilateral osteoarthritis (OA) secondary to developmental dysplasia of the hip (DDH-OA) and primary hip osteoarthritis (PHOA), and the relationship between lower and whole LL asymmetries and femoral length asymmetry. In total, 116 patients who underwent unilateral total hip arthroplasty were included in this study. Of these, 93 had DDH-OA and 23 had PHOA. Patients with DDH-OA were categorized into three groups: Crowe grade I, II/III, and IV. Anatomical femoral length, femoral length greater trochanter (GT), femoral length lesser trochanter (LT), tibial length, foot height, lower LL, and whole LL were evaluated using preoperative CT data of the whole leg in the supine position. Asymmetry was evaluated in the Crowe I, II/III, IV, and PHOA groups.Aims
Methods
This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images. The study analyzed 978 pairs of hip CT and dual-energy X-ray absorptiometry (DXA) measurements of the proximal femur (DXA-BMD) collected from three institutions. From the CT images, the femur and a calibration phantom were automatically segmented using previously trained deep-learning models. The Hounsfield units of each voxel were converted into density (mg/cm3). Then, a deep-learning model trained by manual landmark selection of 315 cases was developed to select the landmarks at the proximal femur to rotate the CT volume to the neutral position. Finally, the CT volume of the femur was projected onto the coronal plane, and the areal BMD of the proximal femur (CT-aBMD) was quantified. CT-aBMD correlated to DXA-BMD, and a receiver operating characteristic (ROC) analysis quantified the accuracy in diagnosing osteoporosis.Aims
Methods
Femoral bone preparation using compaction technique has been shown to preserve bone and improve implant fixation in animal models. No long-term clinical outcomes are available. There are no significant long-term differences between compaction and broaching techniques for primary total hip arthroplasty (THA) in terms of migration, clinical, and radiological outcomes. A total of 28 patients received one-stage bilateral primary THA with cementless femoral stems (56 hips). They were randomized to compaction on one femur and broaching on the contralateral femur. Overall, 13 patients were lost to the ten-year follow-up leaving 30 hips to be evaluated in terms of stem migration (using radiostereometry), radiological changes, Harris Hip Score, Oxford Hip Score, and complications.Aims
Methods
Pelvic tilt (PT) can significantly change the functional orientation of the acetabular component and may differ markedly between patients undergoing total hip arthroplasty (THA). Patients with stiff spines who have little change in PT are considered at high risk for instability following THA. Femoral component position also contributes to the limits of impingement-free range of motion (ROM), but has been less studied. Little is known about the impact of combined anteversion on risk of impingement with changing pelvic position. We used a virtual hip ROM (vROM) tool to investigate whether there is an ideal functional combined anteversion for reduced risk of hip impingement. We collected PT information from functional lateral radiographs (standing and sitting) and a supine CT scan, which was then input into the vROM tool. We developed a novel vROM scoring system, considering both seated flexion and standing extension manoeuvres, to quantify whether hips had limited ROM and then correlated the vROM score to component position.Aims
Methods
Aims. Hip arthroplasty does not always restore normal anatomy. This is due to inaccurate surgery or lack of stem sizes. We evaluated the aptitude of four total hip arthroplasty systems to restore an anatomical and medialized hip rotation centre. Methods. Using 3D templating software in 49 CT scans of non-deformed
Aims. The prevalence of ipsilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA) is rising in concert with life expectancy, putting more patients at risk for interprosthetic femur fractures (IPFFs). Our study aimed to assess treatment methodologies, implant survivorship, and IPFF clinical outcomes. Methods. A total of 76 patients treated for an IPFF from February 1985 to April 2018 were reviewed. Prior to fracture, at the hip/knee sites respectively, 46
The burden of metastatic disease presenting with axial skeleton lesions is exponentially rising predominantly due to advances in oncological therapies. A large proportion is these lesions are located in the proximal
Introduction. Porous surfaces developed over the past decades have been shown to promote tissue ingrowth. Hydroxyapatite (HA) coatings have been added to these porous coatings in an attempt to further augment bone ingrowth. The development of additive manufacturing techniques has allowed for precision in building these complex porous structures. The effect of supplemental HA coatings on these new surfaces is unclear. The purpose of this study is to evaluate the biological fixation of a novel 3D printed porous implant in a canine model. In addition, we evaluated the effect of different HA coatings on this 3D printed implant. Methods. A canine transcortical model was used to evaluate the performance of three different laser rapid manufacturing (LRM) Ti6Al4V cylindrical implants (5.2 mm diameter, 10mm length): LRM with precipitated hydroxyapatite (P-HA), LRM with plasma sprayed hydroxyapatite (PS-HA), and a hydroxyapatite-free control (No-HA). The implants were 50–60% porous with a mean pore size of 450 μm and have a random interconnected architecture with irregular pore sizes and shapes that are designed based on the structure of cancellous bone. A lateral approach to the femoral diaphysis was used to prepare 5 mm unicortical, perpendicular drill holes in 12 canines. One of each implant type was press-fit into each femur. The
Aims. The aim of this study was to estimate the 90-day risk of revision for periprosthetic femoral fracture associated with design features of cementless femoral stems, and to investigate the effect of a collar on this risk using a biomechanical in vitro model. Materials and Methods. A total of 337 647 primary total hip arthroplasties (THAs) from the United Kingdom National Joint Registry (NJR) were included in a multivariable survival and regression analysis to identify the adjusted hazard of revision for periprosthetic fracture following primary THA using a cementless stem. The effect of a collar in cementless THA on this risk was evaluated in an in vitro model using paired fresh frozen cadaveric
Hip fractures are associated with poor outcomes and high mortality rates of 30%. The current gold standard to measure bone fragility is a Dual-Energy X-ray Absorptiometry (DEXA) scan measuring bone mineral density. Yet DEXA under-diagnoses bone fragility by 50% (1). To combat the burden of bone fragility, this experimental study combined ultrasound (US) with a sophisticated computational algorithm, namely full wave inversion (FWI), to evaluate femoral bone structure. The aims were to assess the association of bone structure between the proximal femoral diaphysis and femoral neck; secondly to evaluate whether transverse ultrasound could assess bone structure of the proximal femoral diaphysis. Bone structure of 19 ex vivo human
The computed neck-shaft angle and the size of the femoral component were recorded in 100 consecutive hip resurfacings using imageless computer-navigation and compared with the angle measured before operation and with actual component implanted. The reliability of the registration was further analysed using ten cadaver
The purpose of this prospective study was to
evaluate the long-term clinical and radiological outcomes of revision of
the femoral component of a total hip replacement using impaction
bone grafting. Femoral revision with an impacted allograft was performed
on 29 patients (31 hips). In all, 21 hips (68%) had grade III or
IV femoral defects according to the Endo-Klinik classification.
A total of 11 patients (12 hips) died before the ten-year follow-up
period. Of the remaining patients, 18 patients (19 hips) were followed
for 10 to 15 years; three further patients died during this time.
None of the 31 stems underwent further revision of their stem. However,
four stems showed extensive subsidence (>
15 mm). One of these patients
had a femoral fracture that required fixation. Three other patients
had a femoral fracture, two of which required fixation and the other
was treated conservatively. Patients with a femoral fracture and/or
severe subsidence had significantly more grade IV defects (six of
seven hips; p = 0.004). One patient needed a closed reduction for
dislocation. Impaction allografting in revision hip surgery gives good long-term
results for
This study aimed to assess the effect of flexion and external rotation on measurement of femoral offset (FO), greater trochanter to femoral head centre (GT-FHC) distance, and neck shaft angle (NSA). Three-dimensional femoral shapes (n=100) were generated by statistical shape modelling from 47 CT-segmented right
Unknown femur orientation during X-ray imaging may cause inaccurate radiographic measurements. The aim of this study was to assess the effect of 3D femur orientation during radiographic imaging on the measurement of greater trochanter to femoral head centre (GT-FHC) distance. Three-dimensional femoral shapes (n=100) of unknown gender were generated using a statistical shape model based on a training data of 47 CT segmented
Although CT is considered the benchmark to measure femoral version, 3D biplanar radiography (hipEOS) has recently emerged as a possible alternative with reduced exposure to ionizing radiation and shorter examination time. The aim of our study was to evaluate femoral stem version in postoperative total hip arthroplasty (THA) patients and compare the accuracy of hipEOS to CT. We hypothesize that there will be no significant difference in calculated femoral stem version measurements between the two imaging methods. In this study, 45 patients who underwent THA between February 2016 and February 2020 and had both a postoperative CT and EOS scan were included for evaluation. A fellowship-trained musculoskeletal radiologist and radiological technician measured femoral version for CT and 3D EOS, respectively. Comparison of values for each imaging modality were assessed for statistical significance.Aims
Methods
Introduction. Intraoperative periprosthetic femoral fractures (IOPFF) lead to reduced implant survival. A deeper understanding of predictors enables surgeons to modify techniques and patient selection to reduce the risk of IOPFF. The aim of this study was to estimate predictors of IOPFF and each anatomical subtype (calcar crack, trochanteric fracture, femoral shaft fracture) during primary THA. Methods. This retrospective cohort study included 793823 primary THAs between 2004 and 2016. Relative risks for patient, surgical and implant factors are estimated for any IOPFF fracture and for all anatomical subtypes of IOPFF. Results. Patient factors significantly increasing the risk of fracture were: female gender, American Association of Anaesthesiologists (ASA) grade 3 to 5, pre-operative diagnosis including: avascular necrosis of the hip (AVN), previous trauma, inflammatory disease, paediatric disease and previous infection. Overall risk of IOPFF associated with age was greatest in patients below 50 years and above 80 years. Risk of any fracture reduced with computer guided surgery (CGS) and in non-NHS hospitals. Non-posterior approach's increased the risk of shaft and trochanteric fracture only. Cementless implants only significantly increased the risk of calcar cracks and shaft fractures and not trochanteric fractures. Conclusions. Fracture risk increases in patients less than 50 and older than 80, females, ASA grade 3 to 5 and indications other than primary osteoarthritis. Large cumulative reduction in IOPFF risk may occur with use of cemented implants, posterior approach and CGS. IOPFF may be further reduced by future developments in cementless stem implantation and non-posterior approaches which reduce the intraoperative strain placed on the