Hip Components Research Articles

Клинико-экономический анализ эффективности использования индивидуальных и серийных имплантатов при эндопротезировании тазобедренного и коленного суставов.

One of the pressing issues of modern medicine is the need to improve the results of surgical treatment of patients with stage III osteoarthritis of large joints (according to the classification of N. S. Kosinskaya), as well as with loosening of the components of hip and knee joints through the use of techniques that have high clinical and economic efficiency and including the use of computer modeling and additive 3D printing technologies. Purpose of the study: to conduct a clinical and economic analysis of the effectiveness of using individual and serial components of endoprostheses in the surgical treatment of patients with stage III hip osteoarthritis (according to N. S. Kosinskaya’s classification), as well as with loosening of hip and knee joint implants. Methods: clinical-radiological, computed tomographic, biomechanical, statistical, analytical, sociological. The study included 348 patients who were divided into 10 groups depending on the individual and serial components of implants used in their treatment. Results. The effectiveness of surgical treatment of stage III hip osteoarthritis using individual acetabular implants in primary hip replacement, assessed using QALYs, was 0.79, and the CER (“cost-effectiveness”) indicator was 350,424.7. Moreover, the use of only serial imlants in a similar operation led to a decrease in CER to 262,977.2 and QALY to 0.63. Higher QALYs have also been observed with the use of additive technologies in revision hip arthroplasty. The effectiveness of surgical treatment using individual implants for type IIIa acetabular defect was 0.77 (CER – 341,110), for type IIIb – 0.6 (CER – 496,754.3). When using serial components of a revision hip joint implants for type IIIa acetabular defect, the QALY was 0.4 (CER – 540,462.5), for type IIIb – 0.4 (CER – 653,500.5). The best QALYs (0.15) and CER (1,348,892) were also obtained with the use of individual acetabular implants made of bone cement in hip replacement for periprosthetic infection in comparison with standard spacers (QALY – 0.07; CER – 2,845 801). The effectiveness of surgical treatment of patients with bone defects of type 2B and 3 according to AORI using individual implants during revision knee arthroplasty was 0.83 (CER – 494,236.8), using serial designs – 0.44 (CER – 939,489, 4). Conclusions. The use of individual implants in total replacement in patients with stage III hip osteoarthritis (according to N. S. Kosinskaya’s classification), as well as loosening of hip and knee implants, made it possible to achieve higher rates of effectiveness of surgical treatment in comparison with implantation of only serial structures. The use of additive 3D printing technologies in all cases, except knee joint replacement for bone defects of types 2B and 3 according to AORI, led to increased costs for treating patients. As a result of the clinical and economic analysis, it was revealed that the use of individual implants made using 3D printing in revision hip arthroplasty for IIIa and IIIb defects of the acetabulum, septic loosening of the components of a previously installed implants, as well as in re-replacement of the knee joint in the presence of AORI type 2B and 3 bone defects achieves the best cost-effectiveness ratio (CER) and is “strongly preferable” to implantation of serial constructs only.

Running-in behavior of dual-mobility cup during the gait cycle: A finite element analysis.

The running-in process is considered an essential aspect of the comprehensive wear process. The phenomenon of running-in occurs during the initial stages of wear in the prosthetic hip joint. Within the field of tribology, the running-in phenomenon of the hip joint pertains to the mechanism by which the contact surfaces of the artificial hip joint components are adjusted and a suitable lubricating film is formed. During the process of hip joint running-in, there is an interaction between the metal surface of the ball and the joint cup, which results in adjustments being made until a steady state is achieved. The achievement of desirable wear existence and reliable performance of artificial hip joint components are reliant upon the tribological running-in of the hip joint. Despite the establishment of current modeling approaches, there remains a significant lack of understanding concerning running-in wear, particularly the metal-on-polyethylene (MoP) articulations in dual-mobility cups (DMC). An essential aspect to consider is the running-in phase of the dual mobility component. The present study employed finite element analysis to investigate the running-in behavior of dual mobility cups, wherein femoral head components were matched with polyethylene liners of varying thicknesses. The analysis of the running-in phase was conducted during the normal gait cycle. The results of this investigation may be utilized to design a dual-mobility prosthetic hip joint that exhibits minimal running-in wear.

A novel method of fabricating multi‐material acetabular liner using fused filament fabrication

AbstractTotal hip arthroplasty (THA) involves the replacement of damaged or worn‐out hip components with artificial implants. Frequently revision surgeries were performed due to the failure of the implant. The liners are the ones that are replaced in the majority of the revision surgeries. Researchers are constantly finding different materials to overcome the difficulties being faced. The acetabular liners are fabricated by compression molding and milling using single materials such as Polyethylene, Polyether–ether–ketone (PEEK), and recently Ultra‐High Molecular Weight Polyethylene (UHMWPE), and so forth. Poly Lactic Acid (PLA) being biocompatible and cheaper than UHMWPE is employed in the research. The biodegradable nature of PLA is countered by introducing a nonbiodegradable yet biocompatible High Impact Polystyrene (HIPS). This research attempts to propose and fabricate a novel design of the liner with PLA sandwiched between HIPS by fused filament fabrication, the widely used additive manufacturing technique. The dimensional accuracy and surface roughness of the liners are measured and compared with single‐material liners. The multi‐material liner demonstrated superior dimensional accuracy compared to PLA liner and also exhibiting a smoother surface finish. Dynamic Mechanical Analysis is conducted to determine the capability of printing and also the scanning electron microscopic (SEM) images are used for supporting the results.Highlights Novel design of Acetabular Liner. Use of additive manufacturing for fabrication of implant parts. More than one material used to reap benefits from the two materials used. Measurement of dimensional accuracy, surface roughness of multi‐material liner. Comparison of single and multi‐material liner.

Complete analysis of the subgiant stellar system: HIP 102029

In this work, we present a detailed analysis of the individual components of the visual binary system HIP 102029 (R.A. = 20:40:35.32, Dec. = +15:38:35.63). The system was discovered during the European Space Agency Hipparcos mission and has a separation of 220 mas. The analysis uses the ORBITX code and Al-Wardat’s method to estimate the orbital, atmospheric, and fundamental parameters of the individual components. The positions of the components on the H-R diagram, evolutionary tracks, and isochrones are determined using the estimated parameters. The age of the system is estimated to be 1.415 Gyr with a higher metallicity than the Sun Z=0.030 based on the Gaia BP/RP spectrum. The results show that component A has evolved from the main sequence to the sub-giant stage, while component B has started to evolve off the main sequence. This study provides valuable insights into the properties and evolution of binary star systems, which can contribute to our broader understanding of stellar evolution in the subgiant stage.

The role of 3-dimensional preoperative planning for primary total hip arthroplasty based on artificial intelligence technology to different surgeons: A retrospective cohort study.

Preoperative planning with computed tomography (CT)-based 3-dimensiona (3D) templating has been achieved precise placement of hip components. This study investigated the role of the software (3-dimensional preoperative planning for primary total hip arthroplasty [THA] based on artificial intelligence technology, artificial intelligence hip [AIHIP]) for surgeons with different experience levels in primary THA. In this retrospective cohort study, we included patients, who had undergone THA with the help of the AIHIP, and matched to patients, who had undergone THA without the help of the AIHIP, by age and the doctor who operated on them. The subjects were divided into 4 groups, senior surgeon (Chief of Surgery) with AIHIP group, senior surgeon without AIHIP group, junior surgeon (Associate Chief of Surgery) with AIHIP group and junior surgeon without AIHIP group. The general data, imaging index, clinical outcomes and accuracy of stem size prediction and cup size prediction were retrospectively documented for all patients. There was a significant difference in discrepancy in leg length (P = .010), neck-shaft angle (P = .025) and femoral offset (P = .031) between the healthy side and the affected side, operation duration (P < .001), decrease in hemoglobin (Hb) per 24 hours (P = .046), intraoperative radiation exposure frequency (P < .050) and postoperative complications (overall P = .035) among the patients in junior surgeon group. No significant differences were found between senior surgeon groups with respect to discrepancy in leg length (P = .793), neck-shaft angle (P = .088)and femoral offset (P = .946) between the healthy side and the affected side, operation duration (P = .085), decrease in Hb per 24 hours (P = .952), intraoperative radiation exposure frequency (P = .094) and postoperative complications (overall P = .378). The stem sizes of 95% were accurately estimated to be within 1 stem size, and 97% of the cup size estimates were accurate to within 1 cup size in senior surgeon group with AIHIP. A total of 87% stem sizes were accurately estimated to be within 1 stem size, and 85% cup sizes were accurate to within 1 cup size in junior surgeon group with AIHIP. In conclusion, our study suggests that an AI-based preoperative 3D planning system for THA is a valuable adjunctive tool for junior doctor and should routinely be performed preoperatively.

Speckle-interferometric Study of Close Visual Binary System HIP 11253 (HD 14874) using Gaia (DR2 and EDR3)

We present a comprehensive set of physical and geometrical parameters for each of the components of the close visual binary system HIP 11253 (HD 14874). We present an analysis for the binary and multiple stellar systems with the aim to obtain a match between the overall observational spectral energy distribution of the system and the spectral synthesis created from model atmospheres using Al-Wardat's method for analyzing binary and multiple stellar systems. The epoch positions are used to determine the orbital parameters and the total mass. The parameters of both components are derived as: , , logga = 4.55, loggb = 4.60, R a = 1.125 R ⊙, R b = 0.88 R ⊙, L a = 1.849 L ⊙, L b = 0.342 L ⊙. Our analysis shows that the spectral types of the components are F9 and K3. By combining the orbital solution with the parallax measurements of Gaia DR2 and EDR3, we estimate the individual masses using the H-R diagram as M a = 1.09 M ⊙ and M b = 0.59 M ⊙ for using Gaia DR2 parallax and M a = 1.10 M ⊙ and M b = 0.61 M ⊙ for using Gaia EDR3 parallax. Finally, the location of both system's components on the stellar evolutionary tracks is presented.

A novel algorithm to efficiently calculate the impingement-free range of motion of irregularly-shaped total hip arthroplasty components.

There is great difficulty in quickly calculating the impingement-free range of motion (IFROM) of hip components with complex shapes after total hip arthroplasty. We have established a new algorithm to investigate the effect of different shapes of hip components on the IFROM and impingement-free safe zone (IFSZ). Then find the best combination of hip prosthesis and the optimal mounting position of the elevated-rim liner under different radiographic anteversion (RA) and radiographic inclination (RI) of the cup. We found the larger the opening angle of the beveled-rim liner and the smaller the cross-sectional area of the stem neck with an inverted teardrop cross-sectional shape, the greater the IFROM of the hip component. The beveled-rim liner in combination with the stem neck with an inverted teardrop-shaped cross-section could provide the greatest IFSZ (excluding the flat-rim liner). The optimal orientation of the elevated-rim liner was the posterior-inferior side (RI ≤ 37°), posterior-superior side (RI ≥ 45°), and posterior side (37° ≤ RI ≤ 45°). Our novel algorithm provides a solution to analyze the IFROM of any hip prosthesis with any complex shape. The shape and size of the cross-section of the stem neck, the orientation of the elevated rim, and the shape and opening angle of the liner are all critical factors for the quantitative calculation of the IFROM and mounting safe zone of the prosthesis. Stem necks with inverted teardrop cross-section and beveled-rim liner improved the IFSZ. The optimal direction of the elevated rim is not constant but varies with RI and RA.

A comprehensive and comparative study of microstructure and mechanical properties for post-process heat treatment of AlSi7Mg alloy components fabricated in different laser powder bed fusion systems

AlSi7Mg (F357) alloy specimens were fabricated in two different laser powder bed fusion (LPBF) systems: EOS M290 and SLM 280HL. Vertical (Z) and horizontal (XY) orientations were fabricated, and five different thermal post processes were applied to samples, individually. According to ASTM F3318-18, the considered thermal conditions were as-built, stress relieved (SR1), HIP, T6 and HIP+T6. Subsequently, the individual samples were aged at 140 °C and 177 °C for 100 h and for up to 1000 h. Tensile specimens were machined down from the aged samples and tested as per ASTM E8/E8M-21. While the yield stress (YS), elongation (%), and Vickers microindentation hardness (HV) were somewhat different for the as-built components, the general trends for the different heat treatments were essentially the same. As-built and SR1 treated microstructures were dominated by microdendritic cells, while the HIP, T6 and T6 + HIP component microstructures consisted of recrystallized grains containing eutectic Si particles of various sizes and shapes within the grain interiors and the grain boundaries; which gave rise to wide-ranging mechanical properties. As an example of these widely-ranging mechanical properties, it was observed that components fabricated in the Z or build direction in the EOS system exhibited a YS, elongation, and HV of 225 MPa, 13%, and HV120, while when HIPed and unaged exhibited values of 87 MPa, 25%, and HV51, respectively. These same HIPed components when aged at 177 °C for 1000 h exhibited values of 81 MPa, 41% and HV44. The mechanical properties of the unaged, HIPed and aged fabricated in Z direction in SLM system were 85 MPa, 31%, HV51, and 80 MPa, 42%, and HV47, respectively, providing support for LPBF system fabrication compatibility. These measured mechanical property values represent a small fraction of the more than 1600 mechanical property measurements (YS, UTS, elongation, and hardness (HV)) in this study.

CUSTOM ACETABULAR TRI-FLANGE AND FEMORAL OSSEOINTEGRATION COMPONENTS FOR THE TREATMENT OF SYMPTOMATIC IPSILATERAL HIP AND KNEE ARTHROPATHY IN A PATIENT WITH PROXIMAL FEMORAL FOCAL DEFICIENCY: A NOVEL SOLUTION TO A CHALLENGING PROBLEM

Proximal femoral focal deficiency is a congenital disorder of malformation of the proximal femur and/or the acetabulum. Patients present with limb length discrepancy and clinical features along a spectrum of severity. As these patients progress through to skeletal maturity and on to adulthood, altered biomechanical demands lead to progression of arthropathy in any joint within the lower limb. Abnormal anatomy presents a challenge to surgeons and conventional approaches and implants may not necessarily be applicable.We present a case of a 62-year-old lady with unilateral proximal femoral focal deficiency (suspected Aitken Class A) who ambulated with an equinus prosthesis for her entire life. She presented with ipsilateral knee pain and instability due to knee arthritis but could not tolerate a total knee arthroplasty due to poor quadriceps control.A custom osteointegration prosthesis was inserted with a view to converting to the proximal segment to a total hip replacement if required. The patient went on to develop ipsilateral symptomatic hip arthritis but altered acetabular anatomy required a custom tri-flange component (Ossis, Christchurch, New Zealand) and a custom proximal femoral component to link with the existing osseointegration component (Osseointegration Group of Australia, Sydney, Australia) were designed and implanted.The 18 month follow up of the custom hip components showed that the patient had Oxford hip scores that were markedly improved from pre-operatively. Knee joint heights were successfully restored to equal when the patient's prosthesis was attached. The patient describes feeling like “a normal person”, walks unaided for short distances and can ambulate longer distances with crutches.Advances in design and manufacture of implants have empowered surgeons to offer life improving treatments to patients with challenging anatomy. Using a custom acetabular tri-flange and osseointegration components is one possible solution to address symptomatic ipsilateral hip and knee arthropathy in the context of PFFD in adulthood.

Evaluation of radiological indices of the spine and pelvis ratios in children with a severe form of slipped capital femoral epiphysis

BACKGROUND: Slipped capital femoral epiphysis is one of the most severe diseases of the hip joint in children and is characterized by the displacement of the proximal femoral epiphysis, occurring as a result of a decrease in the mechanical strength of its growth plate. Some pathological processes in the hip joints and lumbosacral spine cause changes in the position (vergence) of the pelvis in the sagittal plane and the development of degenerative dystrophic diseases. The analysis of the spinepelvis relationships in children with slipped capital femoral epiphysis may provide the basis for the development of new approaches to the surgical correction of the deformity of the hip component of the affected joint.&#x0D; AIM: To assess the radiological parameters of the frontal and sagittal spinepelvis relations in children with proximal femur deformity in slipped capital femoral epiphysis.&#x0D; MATERIALS AND METHODS: The study included 30 patients (30 hips) aged 1114 years with a severe form of slipped capital femoral epiphysis characterized by the presence of a posterior displacement of the epiphysis of 60 combined with the downward displacement of no more than 10 in one of the joints and absence of displacement (pre-slip stage) in the other. Patients underwent clinical and radiological examinations. The radiographs taken in the standing position were used to assess the values of thoracic kyphosis and lumbar lordosis, pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), sagittal vertical axis (SVA), and spinesacral angle (SSA). The obtained data were subjected to statistical processing.&#x0D; RESULTS: The patients had pelvic retroversion (decreased values of the PI and SS indices and increased PT index) and formed hypolordotic type of vertical posture according to P. Roussouly classification. In addition, thoracic hyperkyphosis occurred, and the SVA shifted to the front, which can be considered a mechanism of trunk balance compensation for the existing pelvic retroversion and reduction of lumbar lordosis to maintain the ability to move in an upright position.&#x0D; CONCLUSIONS: Children with this severe form of slipped capital femoral epiphysis are characterized by pelvic retroversion, decreased lumbar lordosis and increased thoracic kyphosis, positive trunk imbalance, and PT toward the affected limb. Planning and reconstructive restorative interventions on the affected hip joint should consider existing pathological changes to restore the correct spinepelvis relationships and prevent degenerative dystrophic processes in the lumbosacral spine.

Important feature identification for perceptual sex of point-light walkers using supervised machine learning.

The present study aimed to elucidate the dynamic features that are highly predictive in the biological and perceptual sex classification of point-light walkers (PLWs) and how these features behave in sex classification using supervised machine learning. Fifteen observers judged the sex of 21 PLWs from a side view. A fast Fourier transform was applied to retrieve the spectral components from the multiphasic hip and shoulder movements. An exhaustive search identified the most important features for biological and perceptual sex classifications. An individual conditional expectation (ICE) with a support vector machine (SVM) model was used to interpret the behavior of each important feature. The observers judged the biological sex from side-view PLWs with an accuracy of 62.9% for 10 male PLWs and of 57.0% for 11 female PLWs. The SVM model for biological sex prediction demonstrated that the third harmonic of hip motion played a dominant role in achieving a high predictive accuracy of 90.5% with few feature interactions. In the model of perceptual sex prediction, however, an accurate prediction of 85.7% was achieved using five spectral components of hip and shoulder motions, where the ICE plots of the features followed heterogeneous courses, suggesting feature interactions. The machine learning model suggests that biological sex classification depends mainly on local cues of the PLW. However, the high-performance model of perceptual sex classification involves interactions of various frequency components of hip and shoulder motions, suggesting more complex processes in sex perception.

Ultrasonic bone cement removal efficiency in total joint arthroplasty revision: A computer tomographic-based cadaver study.

Polymethylmethacrylate (PMMA) removal during septic total joint arthroplasty revision is associated with a high fracture and perforation risk. Ultrasonic cement removal is considered a bone-preserving technique. Currently, there is still a lack of sound data on efficacy as it is difficult to detect smaller residues with reasonable technical effort. However, incomplete removal is associated with the risk of biofilm coverage of the residue. Therefore, the study aimed to investigate the efficiency of ultrasonic-based PMMA removal in a human cadaver model.The femoral components of a total hip and a total knee prosthesis were implanted in two cadaver femoral canals by 3rd generation cement fixation technique. Implants were then removed. Cement mantle extraction was performed with the OSCAR-3-System ultrasonic system (Orthofix®). Quantitative analysis of cement residues was carried out with dual-energy and microcomputer tomography.With a 20 µm resolution, in vitro microcomputer tomography visualized tiniest PMMA residues. For clinical use, dual-energy computer tomography tissue decomposition with 0.75 mm resolution is suitable. With ultrasound, more than 99% of PMMA was removed. Seven hundred thirty-fourresidues with a mean volume of 0.40 ± 4.95 mm3 were identified with only 4 exceeding 1 cm in length in at least one axis.Ultrasonic cement removal of PMMA was almost complete and can therefore be considered a highly effective technique. For the first time, PMMA residues in the sub-millimetre range were detected by computer tomography. Clinical implications of the small remaining PMMA fraction on the eradication rate of periprosthetic joint infection warrants further investigations.

Hamstring Flexibility in Adolescent with or Without Plantar Flexion- A Narrative Review.

Background: Flexibility is a property of the muscle to be lengthened to achieve required range of motion. Hamstring muscle constitutes posterior compartment of thigh, which consists of semimembranosus and semitendinosus, biceps femoris, and primarily response for knee flexion. As the age progress, there is physiological shortening of hamstring muscle due to various reasons. Objectives: Is to review the literature for hamstring flexibility measurement in relation to plantar flexors in adolescent between 12 to 19 years. Methods: The analysis of literature was done through Google Scholar, PUBMED, and EMBASE MEDLINE. The review period is from 2016 to 2021 which includes articles of full text English originated. Results and conclusion: In search of article we found 50 articles out of it there were 14 articles which describe about the assessment of hamstring flexibility. There are different assessment tool were used to find the hamstring flexibility. However, there is limited literature associated to hamstring flexibility with or without plantar flexion. There is dearth of literature review on the adolescent for hamstring flexibility, positive review of comparison of study between plantar flexion and neutral position, back saver sit and reach test is more comfortable test than other test. In addition to it adapted sit &amp; reach box has absolute validity &amp; reliability and there is negative correlation between thoracic spine and hip component for the same. Keywords: Hamstring Flexibility, Sit and Reach box (SRT), Back Saver sit and Reach box test (BSRT) and Chair Sit and Reach Test (CSRT).

The accuracy of component positioning during revision total hip arthroplasty using 3D optical computer-assisted navigation.

Despite the excellent outcomes associated with primary total hip arthroplasty (THA), implant failure and revision continue to burden the healthcare system. The use of computer-assisted navigation (CAN) offers the potential for more accurate placement of hip components during surgery. While intraoperative CAN systems have been shown to improve outcomes in primary THA, their use in the context of revision total hip arthroplasty (rTHA) has not been elucidated. We sought to investigate the validity of using CAN during rTHA. A retrospective analysis was performed at an academic medical institution identifying all patients who underwent rTHA using CAN from 2016-2019. Patients were 1:1 matched with patients undergoing rTHA without CAN (control) based on demographic data. Cup anteversion, inclination, change in leg length discrepancy (ΔLLD) and change in femoral offset between pre- and post-operative plain weight-bearing radiographic images were measured and compared between both groups. A safety target zone of 15-25° for anteversion and 30-50° for inclination was used as a reference for precision analysis of cup position. Eighty-four patients were included: 42 CAN cases and 42 control cases. CAN cases displayed a lower ΔLLD (5.74 ± 7.0mm vs 9.13 ± 7.9mm, p = 0.04) and greater anteversion (23.4 ± 8.53° vs 19.76 ± 8.36°, p = 0.0468). There was no statistical difference between the proportion of CAN or control cases that fell within the target safe zone (40% vs 20.9%, p = 0.06). Femoral offset was similar in CAN and control cases (7.63 ± 5.84mm vs 7.14 ± 4.8mm, p = 0.68). Our findings suggest that the use of CAN may improve accuracy in cup placement compared to conventional methodology, but our numbers are underpowered to show a statistical difference. However, with a ΔLLD of ~ 3.4mm, CAN may be useful in facilitating the successful restoration of pre-operative leg length following rTHA. Therefore, CAN may be a helpful tool for orthopedic surgeons to assist in cup placement and LLD during complex revision cases.

Dual-scale single marker calibration for digital templating of total hip arthroplasty in standing radiographs: a prospective clinical study

PurposeAccuracy of calibration of radiographs significantly influences the quality of digital templating for total hip arthroplasty (THA). The standard of care is calibration with external calibration markers (ECM). This method is associated with significant errors. Dual-scale single marker (DSSM) calibration methods may improve accuracy. The present prospective observational study is the first to analyze the application of a DSSM method in standing pelvis radiographs.Methods100 patients with unilateral THA underwent antero-posterior pelvis radiographs with ECM and DSSM. The hip components were used as reference calibration factor (internal calibration factor; ICM). Absolute differences of calibration factors for ECM and DSSM from ICM were calculated. Absolute relative deviations (ARD) were calculated. Subgroup analysis for sex and WHO BMI category was performed. Furthermore, patients reported subjective comfort for each marker using a 10-point scale and choosing the preferred marker.ResultsMaximum magnification factor differences from the ICM were 23.3% and 9.5% and mean absolute differences were 12.5% and 2.1% for the ECM and DSSM, respectively. ARD from ICM was significantly lower for DSSM compared to ECM (p < 0.001). Absolute differences increased with BMI category using ECM; calibration by DSSM was consistent in all subgroups. Patients preferred DSSM over ECM (n = 53) or were indifferent (n = 20). Comfort was rated significantly higher for DSSM versus ECM (p < 0.001).ConclusionDSSM method showed superior results in comparison to the ECM method for calibration of digital radiographs. DSSM could be used to improve digital templating in standing radiographs.

Definition of Developmental Dysplasia of the Hip

Existing definitions of developmental dysplasia of the hip (DDH) lack uniformity. This study reviewed the main articles discussing DDH definition to make a uniform, feasible, and clinically relevant definition. Electronic databases with some orthopedic books were used to search for the relevant articles. The articles included were 26 (13 from journals and 13 from books). They were published in the last three decades, in the English language, and related to the human species. The retrieved descriptive data used to define DDH were summarized and sorted according to the concepts they contained (they were 12 concepts). Most of them gave more than one set of data to define DDH. From the summary of these data, it can be concluded that DDH can be defined as a developmental spectrum of abnormal formation and alignment of hip joint components that present in healthy infants.

Effect of Rearfoot Strikes on the Hip and Knee Rotational Kinetic Chain During the Early Phase of Cutting in Female Athletes

BackgroundBiomechanical factors affecting horizontal-plane hip and knee kinetic chain and anterior cruciate ligament (ACL) injury risk during cutting maneuvers remain unclear. This study aimed to examine whether different foot strike patterns alter horizontal-plane hip and knee kinetics and kinematics during a cutting maneuver in female athletes and clarify the individual force contribution for producing high-risk hip and knee loadings. Twenty-five healthy female athletes performed a 60° cutting task with forefoot and rearfoot first strike conditions. Horizontal-plane hip and knee moment components, angles, and angular velocities were calculated using synchronized data of the marker positions on the body landmarks and ground reaction forces (GRFs) during the task. The one-dimensional statistical parametric mapping paired t test was used to identify the significant difference in kinetic and kinematic time-series data between foot strike conditions.ResultsIn the rearfoot strike condition, large hip and knee internal rotation loadings were produced during the first 5% of stance due to the application of GRFs, causing a significantly larger hip internal rotation excursion than that of the forefoot strike condition. Dissimilarly, neither initial hip internal rotation displacement nor knee internal rotation GRF loadings were observed in the forefoot strike condition.ConclusionsRearfoot strike during cutting appears to increase noncontact ACL injury risk as the GRF tends to produce combined hip and knee internal rotation moments and the high-risk lower limb configuration. Conversely, forefoot strike during cutting appears to be an ACL-protective strategy that does not tend to produce the ACL-harmful joint loadings and lower extremity configurations. Thus, improving foot strike patterns during cutting should be incorporated in ACL injury prevention programs.

Hip screening in newborns in the UK: what are the latest guidelines?

The Newborn and Infant Physical Examination screening is a national screening programme which aims to identify infants with congenital abnormalities to minimise the risk of long-term complications. It involves a top to toe examination with special focus on the heart, eyes, testes and hips. The hip component of the Newborn and Infant Physical Examination screen aims to pick up infants with developmental dysplasia of the hips and refer them for appropriate treatment in a timely manner. Guidelines for the hip section of have recently changed. This article reviews these changes, the timings of the follow up and investigations, and the diagnosis and management of developmental dysplasia of the hips.

Sound side trunk muscles contribute to trunk control during prosthetic gait in persons with unilateral transfemoral amputation

The incidence of knee and hip joint osteoarthritis in subjects with below knee amputation (BK) appears significantly higher compared to unimpaired subjects, especially in the intact side. However, it is controversial if constant higher loads on the sound side are one of the major factors for an increased osteoarthritis (OA) incidence in subjects with BK, beside other risk factors, e.g. with respect to metabolism. The aim wasto investigate joint contact forces (JCF) calculated by a musculoskeletal model in the intact side and to compare it with those of unimpaired subjects and to further elucidate in how far increased knee JCF are associated with increased frontal plane knee moments. A group of seven subjects with BK amputation and a group of ten unimpaired subjects were recruited for this study. Gait data were measured by 3D motion capture and force plates. OpenSim software was applied to calculate JCF. Maximum joint angles, ground reaction forces, and moments as well as time distance parameters were determined and compared between groups showing no significant differences, with some JCF components of knee and hip even being slightly smaller in subjects with BK compared to the reference group. This positive finding may be due to the selected ESAR foot. However, other beneficial factors may also have influenced this positive result such as the general good health status of the subjects or the thorough and proper fitting and alignment of the prosthesis.

The impact of functional combined anteversion on hip range of motion: a new optimal zone to reduce risk of impingement in total hip arthroplasty.

AimsPelvic 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.MethodsWe 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.ResultsThe vast majority of THA planned with standing combined anteversion between 30° to 50° and sitting combined anteversion between 45° to 65° had a vROM score > 99%, while the majority of vROM scores less than 99% were outside of this zone. The range of PT in supine, standing, and sitting positions varied widely between patients. Patients who had little change in PT from standing to sitting positions had decreased hip vROM.ConclusionIt has been shown previously that an individual’s unique spinopelvic alignment influences functional cup anteversion. But functional combined anteversion, which also considers stem position, should be used to identify an ideal THA position for impingement-free ROM. We found a functional combined anteversion zone for THA that may be used moving forward to place total hip components.Cite this article: Bone Jt Open 2021;2(10):834–841.