Introduction. After total hip arthroplasty, dislocation is one of the most frequent serious early complications. This occurs in part due to impingement (catching and leverage of the neck-cup on the inlay/cup border). Impingement may also negatively impact long-term outcomes. Materials and Methods. A preliminary model for an optimised hip endoprosthesis system was developed to offer a mechanical solution to avoid impingement and dislocation. A computer-supported range of motion simulation using parameters of cup anteversion and inclination as well as torsion and CCD shaft angle was then performed to localise areas of anterior and posterior impingement of typical acetabular cups. Results. Through isolation of the two main trajectories of motion, and modifications with corresponding gaps to the inlay/cup areas as well as oppositional banking in the abduction/adduction plane, the combination of a snap-fit acetabular cup with reduced cup profile was the result: the “bidirectional
Aims: The authors report oncological and functional results after 15 acetabular reconstructions, followed tumor resection, with an original technique using homo-lateral proximal femoral autograft and
Because we encountered a high failure rate of the acetabular component of the uncemented, hydroxy-apatite coated, Omnifit
The ABG
Purpose: The surgical approach is an essential element for precise reduction and rigid fixation of fractures of the acetabulum. In cases where the anterior column is mainly involved and total hip arthroplasty (THA) is indicated, classical approaches do not allow double assess to the anterior column necessary for reduction and fixation and to the femoral canal for insertion of the prosthesis. Combining Heuter’s anterior approach and Letournel’s ilio-femoral approach provides access to the anterior column and to the often associated posterior hemi-transverse fracture, while allowing insertion of the
Introduction. Total hip arthroplasty in young patients is still associated with high failure rates, especially at the acetabular side. Purpose of this study was to evaluate the long-term results of the Alloclassic cementless Zweymüller
Purpose: Wear of prosthetic implants, especially the metal-polyethylene head-cup couple, and dissemination of wear particles throughout the organisms the dominant long-term complication of total hip arthroplasty. We determined serum concentrations of chromium, cobalt, nickel, and molybdenum in patients bearing a
Introduction: “Spongiosa metal” this unique implant surface was introduced in 1982 by ESKA implants Germany. Pore size was between 800 and 1500 microns with an overall porosity of 60%. The pore depth of the interconnecting surface structure reached up to 3000 microns. The purpose of this retrospective study is to report the long term results of Spongiosa Metal I cement less
Purpose: A spacer can be used for two-phase replacement of an infected
SL-PLUS MIA stem (Smith & Nephew Orthopaedics AG) is a modified implant of Zweymuller type SL-PLUS standard stem (Smith & Nephew Orthopaedics AG). We constructed finite element (FE) models and analysed equivalent stresses in the femur. In addition, we measured bone mineral density (BMD) in the femur by dual-energy X-ray absorptiometry (DEXA) after THA. The purpose of this study was to investigate the equivalent stress and to compare the results of the FE analyses with changes in BMD after THA. Twenty-one patients (18 women and 3 men) who underwent primary cementless THA with SL-PLUS MIA or SL-PLUS formed the basis of this study. Eleven patients received SL-PLUS MIA and ten patients received SL-PLUS. Zones were defined according to Gruen's system (zones 1∼7). Computed-tomography (CT) images of the femur were taken before and at 1 week after THA. FE models of the femur and prosthesis were obtained from CT data by Mechanical Finder (Research Center of Computational Mechanics Inc., Tokyo, Japan), software that creates FE models showing individual bone shape and density distribution. Equivalent stresses were analysed in zones 1 to 7 and compared to the DEXA data. FE studies revealed that there was no significant difference in equivalent stress between SL-PLUS MIA and SL-PLUS. BMD was maintained after THA in zones 3, 4, and 5, whereas BMD decreased in zones 2, 6, and 7. In zone 1, BMD decreased in SL-PLUS MIA stem group by 14%, while BMD was maintained in SL-PLUS standard stem.
Introduction: Unique spongiosa like surface structure was introduced in 1982 by ESKA implants Germany. It is called “Spongiosa-Metal I surface” The purpose of this retrospective study is to report and compare long term results of Spongiosa Metal I
INTRODUCTION. Cementless Total Hip Replacement surgery is a well established procedure for relative young patients with severe hip disease. Excellent long term clinical results have been published on the performance of the femoral component. With growing clinical experience, our concern focused on excessive wear of the Ultra High Molecular Weight Polyethylene (UHMWPE) ringloc liner of the Mallory Head cementless
Total Hip Arthroplasty (THA) is a well-established, cost-effective treatment for improving function and alleviating pain in patients who have disabling hip disease with excellent long-term results. Based on the excellent results, there is an ongoing trend for THA to be performed in younger and more active patients, having higher physical demands on their new total joints. Polyethylene (PE) wear and its biological consequences are one of the main causes of implant failure in THA. Macrophages phagocytise PE wear particles and this will result in osteolysis and loss of periprosthetic bone. The risk of these complications can be estimated in relation to the amount of volumetric wear based on two assumptions: that the number of PE particles dispersed in the peri-prosthetic tissues is controlled by the amount of PE wear; and that the development of osteolysis and the resulting aseptic loosening is triggered by these PE particles. Based on these assumptions, a model was developed to estimate the osteolysis-free life of a THA, depending on the Linear Wear Rate (LWR) and femoral head size of the PE bearing. A review of the literature was conducted to provide an estimate of the radiologic osteolysis threshold based on the volumetric wear of the PE bearing. This review demonstrates that this radiologic osteolysis threshold is approximated 670 mm3 for conventional PE. The osteolysis-free life of the THA was estimated by simply dividing this threshold volume by the annual Volumetric Wear Rate (VWR) of the bearing. The annual VWR is basically controlled by two parameters: (1) annual LWR and (2) head size, and was calculated by using published formulae. For 28 mm heads, following osteolysis-free life was determined in function of the annual LWR. LWR: 10 µm/y => 116.6 years / LWR: 25 µm/y => 46.6 years / LWR: 50 µm/y => 23.3 years / LWR: 100 µm/y => 11.6 years. For 40 mm heads, following osteolysis-free life was determined in function of the annual LWR. LWR: 10 µm/y => 57.1 years / LWR: 25 µm/y => 22.9 years / LWR: 50 µm/y => 11.4 years / LWR: 100 µm/y => 5.7 years. The osteolysis-free life determined by this model is in good agreement with the clinical results of PE bearings having a 28 mm head size and demonstrates that extreme low LWRs are mandatory to assure a descent osteolysis-free life for THA (PE bearings) using large heads, such as 40 mm. For such head sizes, small variations of the LWR may have large impacts on the osteolysis-free life of the THA.
Between January 1984 and January 1986, 131 porous-coated anatomic total hip replacements were performed in 119 consecutive patients. Of these, 100 patients (110 hips) who were alive at a minimum of 18 years after replacement were included in the study. The mean age of the patients at surgery was 48.4 years and that of surviving patients at the latest follow-up was 67.8 years. The mean duration of the clinical and radiological follow-up was 19.4 years (18 to 20). The mean Harris hip score initially improved from 55 points before to 95 points at two years after operation, but subsequently decreased to 91 points after six years, 87 points after 11.2 years, and 85 points after 19.4 years. At the final follow-up, 23 hips (18%) of the entire cohort and 21% of survivors had undergone revision because of loosening or osteolysis of the acetabular component and eight hips (6%) of the entire cohort and 7% of survivors for loosening or osteolysis of the femoral component. Only four femoral components (4%) were revised for isolated aseptic loosening without osteolysis and two (2%) for recurrent dislocation. On the basis of these long-term results, the porous-coated anatomic femoral component survived for a minimum of 18 years after operation while the acetabular component was less durable. The findings identify the principles of uncemented joint replacement which can be applied to current practice.
Customization makes it possible to fulfill design requirements during MIS-THA procedures, and has helped define the parameters of fit and fill. This study describes the results of using customization techniques to develop a femoral implant for utilization. CT-based design criteria for femoral implants has-been developed and used for primary, cement-less, non-minimally invasive THA surgery. Over 1000 procedures performed with these devices have been associated with displaced femoral fractures, and have been revised for septic loosening. This study has 2 parts:
20 implants were designed and implanted with CT-based criteria that utilized the identical fit and fill standards of the custom implants previously established, but had short (<
115 mm), tapered stems; 20 patients underwent primary, cement-less THR wherein an off-the-shelf femoral implant system was determined to fulfill fit and fill requirements of custom implants. The stem of these implants was shortened (95–115 mm) and tapered. Implants in both groups were inserted using a single incision, posterior-lateral MIS approach. Patients were followed clinically and radiographically for six months. Immediate full weightbearing and use of a single cane were encouraged. The use of CT-based customization techniques is helpful for defining design criteria of femoral implants, but the instrumentation for inserting these implants must be adapted to the specific surgery. Customization also facilitates the design and evaluation of CAOS applications for inserting these MIS implants.
Early reports on revision total hip arthroplasty (RTHA) suggested that outcomes of this procedure are as good as those of primary total hip arthroplasty (THA). However, RTHA is associated with longer surgery time, greater blood loss and increased risk of complications (thromboembolism, nerve injury, periprosthetic fractures, recurrent hip dislocations and infections). Aseptic loosening after RTHA was reported in 36% of patients aged over 55 years within 4 years after revision. Infections were reported in 32% and complications during surgery in 23% of patients respectively. Unsatisfactory results of RTHA stimulate the search for alternative procedures. Girdlestone excision arthroplasty (GA) seems to be a good solution for older patients with high risk of complications related to a poor general condition.
Infection ceased in 9 cases, 1 patient died because of complications related to chronic infection.
We report the clinical outcome and survival of 100 total hip arthroplasties with Link RS cementless hip prostheses after a mean of 63 months (51 to 93). The average preoperative Merle d'Aubigne hip score was 9.4 points and the average score at the latest follow-up was 15.3 points. Thirteen prostheses have been revised and seven await revision. Survivorship analysis based on intention to revise showed only 68% survival at seven years (95% CI 53% to 81%). The survivals of femoral and acetabular components verified to be loose at surgery were 78% and 89% respectively at seven years. A number of other patients have pain and it seems likely that there will be substantial reduction in these survival figures in the future.
Sixty-five total hip arthroplastics were reinserted after sepsis around the hip, positive cultures being obtained from fifty-six. Although 65 per cent of patients still have their implant in position, only sixteen of sixty-five (25 per cent) show an excellent or good result on a Harris rating. Twenty-three of sixty-five (35 per cent) subsequently required an excision arthroplasty. The indications and contraindications for this procedure are given.
Post op cup anatomical and functional orientation is a key point in THP patients regarding instability and wear. Recently literature has been focused on the consequences of the transition from standing to sitting regarding anteversion, frontal and sagittal inclination. Pelvic incidence (PI) is now considered as a key parameter for the analysis of sagittal balance and sacral slope (SS) orientation. It's influence on THP biomechanics has been suggested. Interestingly, the potential impact of this morphological angle on cup implantation during surgery and the side effects on post op functional orientation have not been studied. Our study explores this topic from a series of standing and sitting post-op EOS images 310 patients (mean age 63,8, mean BMI 30,2) have been included prospectively in our current post-operative EOS protocol. All patients were operated with the same implants and technique using anterior approach in lateral decubitus. According to previous literature, 3 groups were defined: low PI less than 45° (57 cases), high PI if more than 60° (63 cases), and standard PI in 190 other cases.Introduction
Material and methods
We enrolled 98 patients (107 hips) with a mean age of 47 years (SD 8.6) into a prospective study of the Madreporic Lord THR; 34 hips had primary and 73 secondary osteoarthritis. After ten years, the survival rate using revision as the endpoint for failure was 70% (±9) for the cup and 98% (±0.3) for the stem. The combined clinical and radiological survival rates were 46% (±11) and 81% (±10), respectively. Osteoporosis due to stress-shielding was observed in the proximal femur. Hips with radiologically dense bone postoperatively showed the most pronounced bone loss. We recommend continued radiological follow-up of patients with this type of implant to allow revision to be performed before there is severe bony destruction of the pelvis.
Twenty-nine patients with thirty pseudarthroses after removal of infected total hip prostheses have been reviewed one to six years later. Six hips still had a discharging sinus. Complete removal of all cement was found to be essential for healing, and various points in the technique of its clearance have been made. In this respect radio-opaque cement was a great advantage, and lateral guttering of the femur was most effective. Compared with the situation before replacement considerable relief of pain was obtained in most patients but there was much less improvement in function.
The aim of this study is to review the relation of polyethylene wear in patients underwent Anatomic Medullary Locking total hip replacement with respect to the types of acetabulum used. 85 cementless primary AML joint replacements were performed in the 10 years period from 1988 to 1998. The average age at operation was 46.6 with a range from 22 to 63. Two different types of acetabulum design namely the Acetabulum Cup System (ACS) and Duraloc were used. 39 of them were followed up from 2 to 10 years with an average of 69 months. Xrays were performed at the review visit and the thickness of the insert was calculated. The cup abduction angle was measured and the size of the cup and initial insert thickness was also recorded. The findings were correlated and subjected to statistical analysis. Our findings suggested that the wear of the ACS cup was significantly higher than that of the Duraloc cup. The size of the cup but not the age of the patient at the time of operation also affects the wear rate. It appears that wear rate started to accelerate from year 8 onwards. The risk is higher with cups of less than 50mm diameter We conclude that it is advisable to review closely those patients with the ACS cup implanted. Revision surgery should be considered if eccentric wear started to be seen on Xray to avoid complicated procedure.
The shape of the femoral canal is variable, infact more variable than most contemporary designs of femoral components would suggest or accommodate. Clinical and experimental studies of total hip replacement have demonstrated the need for a close geometric fit between the femoral component and the supporting bone for a durable implant fixation. In order to provide a basis for design and selection of femoral components in future, we undertook an anthropometric study of proximal femoral geometry on Indian specimens. 74 cadaveric femorae were studied to analyze the difference in the endosteal and periosteal geometry between Indian and Western population. Standard extra-cortical and endosteal dimensions were determined by direct measurements of radiographs. To enable comparison standard horizontal and vertical axis were established using the geometric center of lesser trochanter and the bisecting axis of the medullary canal at the level of the isthmus. Statistically significant differences were found for the following measurements: Femoral head offset, Width at lesser trochanter, Width at lesser trochanter-20mm, Proximal border of isthmus, Neck shaft angle.
All the measurements were done by two independent observers and averaged. From the standard radiographs, the sacral slope (SS), the acetabular frontal inclination (AFI), and the acetabular sagittal inclination (ASI) were measured in standing, sitting, and lying positions. From the CT scan sections, the anatomical ante-version (AA) was measured in lying position on axial images according to Murray. The results were compared to a previously described protocol replicating standing and sitting positions: CTscan sections were oriented according to sacral slope.
Revision surgery is generally recommended for recurrent dislocation following Total hip arthroplasty (THA). However, dislocation following revision THA continues to remain a problem with further dislocation rates upto 28% quoted in literature. We present early results of one of the largest series in U.K. using dual mobility cemented acetabular cup for recurrent hip dislocation. We retrospectively evaluated 40 patients where revision of hip replacement was performed using cemented dual mobility acetabular prosthesis for recurrent dislocations from March 2006 till August 2009 at our district general hospital by a single surgeon (senior author). The series comprised of 13 men and 27 females with average age of 73.4 years (49-92). The mean follow-up period was 23 months. (36 months –6 months). All the hips that were revised had 3 or more dislocations, some them more than 10 times. The cause of dislocation was multifactorial in majority of cases including acetabular component malpositioning mainly due to loosening and wear. A cemented dual mobility cup was used in all cases. In six cases the femoral stem was also revised.Introduction
Methods
There were three true dislocations (2%): 1) a posterior dislocation on day 24 in a female patient presenting a fracture with impaction of the femoral stem; 2) a posterior dislocation on day 22 in a female patient in very poor general condition (severe cardiorespiratory failure, death at 48 hr); 3) one recurrent posterior dislocation related to major acetabular retroversion, revised at four months.
Total hip arthroplasty in adult patients with congenital high dislocation of the hip (DDH, Crowe type IV) presents many challenges. Various reconstruction methods including iliofemoral distraction lenghtening and custom made prosthesis have been reported but the standard technique for dealing with this problem is femoral shortening with a subtrochanteric osteotomy. There are many reports of different subtrochanteric osteotomy techniques with satisfactory results. Since 1999, we have been using the same anatomic reconstruction principles with a proximally hydroxyapatite coated cementless stem. Surgical technique on the femoral side comprises a short oblique subtrochanteric osteotomy and excision of a segment as indicated for a safe reduction. This usually requires extensive soft tissue releases of the pelvifemoral muscles. Gluteus maximus, tensor fascia latae and adductors are routinely released. However, we don’t want to do any more release until it is absolutely necessary. Preserving the attachment of the abductors and iliopsoas are important for eventual functional outcome. They help stabilizing the joint, avoid limping and promote hip flexion during the initial swing phase of the gait and stair climbing. We never resect neither osteotomize the trochanters and, if a release is unavoidable, it is performed proximally. Thus, it is possible to preserve a complete segment of the proximal femur with a soft tissue envelope. This segment allows for better bone stock, prompt healing, reliable proximal fixation through the intact medial calcar and, avoids the complications of trochanteric osteotomy. With this technique we have not observed a femoral revision for any reason in 101 high dislocated hips (in 84 patents), since 1999. Compared with other techniques for arthroplasty in patients with developmental hip dysplasia, this surgical technique has a better functional outcome and a low prevalence of revision. To evaluate the effect of this reconstruction on gait parameters we analyzed the gait cycle in 17 hips in 10 patients before and after the the total hip arthroplasty and compared it with the patients with hip arthroplasty due to primary osteoarthritis. Our aim is to determine the restoration of normal anatomy in DDH patients compared to the patients with total hip arthroplasty but a normal hip anatomy. As a result we have demon-strated that our technique restores normal gait parameters by improving walking speed, lengthening step-stride length, correcting hip and knee flexion and ankle equinus, improving hip and knee stiffness during gait and helps to restore normal gait parameters
We report the long-term radiographic results of the total hip arthroplasty with use of the cementless porous coated Harris-Galante (H-G) stem. Seventy-five consecutive patients, eighty-eight hips formed the basis of this study. Fifty patients were male, twenty-five patients were female, and thirteen patients were bilateral. The mean age of patients at operation was 42 years. They were followed up for an average of thirteen years four months (ten years two months to fourteen years four months). The diagnosis was avascular necrosis of the femoral head in 49 cases, degenerative osteoarthritis in 32 cases. Clinical results were estimated by modified Harris hip score and thigh pain, and radiographic results by periodically checked plain X-ray film. The average Harris hip score increased from 60 points preoperatively to 83 points at the most recent follow-up examination. The hip pain score increased from 31 points to 41 points. Clinically severe thigh pain was observed in 3 cases (4%). In radiographic evaluation, subsidence more than 5mm was seen in 2 cases (2%). Periprosthetic osteolytic lesion was observed in 15 cases (17%), but the lesions do not influence stability of the stem. Femoral stem stability by Engh was stable in 72 cases, fibrous stable in 12 cases, unstable in 4 cases. Pedestal formation, cortical hypertrophy of the distal femur, and stress shielding was observed more than 40%. Subcollar resorption was identified in 29% and ectopic ossification in 15%. Revision of the femoral stem was needed in 4 cases for aseptic loosening. At 10 years probability of survival of the stem using Kaplan-Meyer method was 95.5%. Use of the cementless H-G stem yielded the excellent long-term outcome, but osteolysis and stress shielding would be the main problems to solve.
Ceramic bearings are widely used in total hip arthroplasty (THR) along with metal and polyethylene bearings. There were several studies in past few years evaluating the advantage of one over the other. The young population with high activity levels has an increased risk of wear debris production at bearing surface and subsequent implant failure. Recently, interest and use of a ceramics with high wear resistance has been growing. Early reports on ceramic on ceramic THR have demonstrated excellent clinical and radiological results. To evaluate clinical, functional and radiological outcomes of cement-less ceramic on ceramic primary total Hip Replacement (THR) in young patients (<50 years age) with diagnosis of avascular necrosis femoral head.BACKGROUND CONTEXT
PURPOSE
The aim of this study was to investigate the association between fracture displacement and survivorship of the native hip joint without conversion to a total hip arthroplasty (THA), and to determine predictors for conversion to THA in patients treated nonoperatively for acetabular fractures. A multicentre cross-sectional study was performed in 170 patients who were treated nonoperatively for an acetabular fracture in three level 1 trauma centres. Using the post-injury diagnostic CT scan, the maximum gap and step-off values in the weightbearing dome were digitally measured by two trauma surgeons. Native hip survival was reported using Kaplan-Meier curves. Predictors for conversion to THA were determined using Cox regression analysis.Aims
Methods
Orientation of the acetabular component influences
wear, range of movement and the incidence of dislocation after total
hip replacement (THR). During surgery, such orientation is often
referenced to the anterior pelvic plane (APP), but APP inclination
relative to the coronal plane (pelvic tilt) varies substantially
between individuals. In contrast, the change in pelvic tilt from
supine to standing (dPT) is small for nearly all individuals. Therefore,
in THR performed with the patient supine and the patient’s coronal
plane parallel to the operating table, we propose that freehand placement
of the acetabular component placement is reliable and reflects standing
(functional) cup position. We examined this hypothesis in 56 hips
in 56 patients (19 men) with a mean age of 61 years (29 to 80) using
three-dimensional CT pelvic reconstructions and standing lateral
pelvic radiographs. We found a low variability of acetabular component
placement, with 46 implants (82%) placed within a combined range
of 30° to 50° inclination and 5° to 25° anteversion. Changing from
the supine to the standing position (analysed in 47 patients) was associated
with an anteversion change <
10° in 45 patients (96%). dPT was
<
10° in 41 patients (87%). In conclusion, supine THR appears
to provide reliable freehand acetabular component placement. In
most patients a small reclination of the pelvis going from supine
to standing causes a small increase in anteversion of the acetabular component Cite this article:
Progressive retroversion of a cemented stem is
predictive of early loosening and failure. We assessed the relationship
between direct post-operative stem anteversion, measured with CT,
and the resulting rotational stability, measured with repeated radiostereometric
analysis over ten years. The study comprised 60 cemented total hip
replacements using one of two types of matt collared stem with a
rounded cross-section. The patients were divided into three groups
depending on their measured post-operative anteversion (<
10°,
10° to 25°, >
25°). There was a strong correlation between direct
post-operative anteversion and later posterior rotation. At one
year the <
10° group showed significantly more progressive retroversion
together with distal migration, and this persisted to the ten-year
follow-up. In the <
10° group four of ten stems (40%) had been
revised at ten years, and an additional two stems (20%) were radiologically
loose. In the ‘normal’ (10° to 25°) anteversion group there was
one revised (3%) and one loose stem (3%) of a total of 30 stems,
and in the >
25° group one stem (5%) was revised and another loose (5%)
out of 20 stems. This poor outcome is partly dependent on the design
of this prosthesis, but the results strongly suggest that the initial
rotational position of cemented stems during surgery affects the
subsequent progressive retroversion, subsidence and eventual loosening.
The degree of retroversion may be sensitive to prosthetic design
and stem size, but <
10° of anteversion appears deleterious to
the long-term outcome for cemented hip prosthetic stems. Cite this article:
Introduction. The metal-on-metal (MoM)
Orthopaedic implants, such as femoral heads, sockets and stems, are manufactured with a high degree of smoothness and very low form error in order to function as low wear bearings. The surfaces are subject to both wear and damage during in vivo use. Articulating surfaces naturally wear during normal use. Aseptic loosening associated with osteolysis and release of wear particles is the main reason for revision of total hip arthroplasty (THA). Damage of femoral heads is well known to increase the wear rate at the articulating surface and is vulnerable to scratching during the maneuver of positioning the femoral component into the acetabulum component either in primary as in revision total hip arthroplasties. The findings emphasize the importance of achieving and maintaining good surface finish of the femoral head component. The author presents a very simple and “zero cost” method of preventing scratching of the femoral head of any kind of
Backgrounds. The authors present an analysis of 30 cases of
Postoperative dislocation following total hip arthroplasty (THA) remains a significant concern with a reported incidence of 1% to 10%. The risk of dislocation is multifactorial and includes both surgeon-related (i.e. implant position, component size, surgical approach) and patient-related factors (i.e. gender, age, preoperative diagnosis, neurologic disorders). While the majority of prior investigations have focused on the importance of acetabular component positioning, recent studies have shown that approximately 60% of “dislocators” following primary THA have an acceptably aligned acetabular component. Therefore, the importance of the relationship between the spine and pelvis, and its impact on functional component position has gained increased attention. Kanawade and Dorr et al. have shown patients can be categorised into having a stiff, normal, or hypermobile pelvis based on their change in pelvic tilt when moving from the standing to seated position. The degree of change in functional position of both the acetabular and femoral components is impacted by the degree of pelvic motion each patient possesses. In the “normal” pelvis, as a patient moves from the standing to seated position the pelvis typically tilts posteriorly, thus increasing the functional anteversion of the acetabular component. However, patients with lumbar degeneration or spine pathology often have a decrease in posterior pelvic tilt in the seated position, thus potentially increasing their risk of dislocation. Bedard et al. noted an 8.3% dislocation risk in patients with a spinopelvic fusion after THA vs. 2.9% in those without. There is the potential that preoperative, dynamic imaging can be used to predict the ideal component position for each individual patient undergoing THA. However, this assumes that a patient's preoperative pelvic motion will be the same following implantation of a
Introduction. A 68 year old female patient underwent a left total hip replacement for primary osteoarthritis in March 2004. She was referred back by her GP 5 years as she was struggling with mobility and felt there were mice in her hip. It was squeking so loudly that it could be hear at a distance of 25 metres. There was no history of any falls or dislocation in the last 5 years. The implant used was an Exeter/ABG ceramic
Introduction. Computer navigation is a highly sophisticated tool in orthopedic surgery for component placement in total hip arthroplasty (THA). In order to apply it adequately it is of upmost importance that the targets the surgeon is trying to hit are well-defined. This concept considers all four component orientations: cup inclination (cIncl) and anteversion (cAV), stem antetorsion and neck-to-shaft angle. The optimising goal in this concept is maximising the size of the cSafe-Zone. Methods. A computerised 3D- model of a
Objectives. The cytotoxicity induced by cobalt ions (Co. 2+. ) and cobalt nanoparticles (Co-NPs) which released following the insertion of a
Literature surrounding artificial intelligence (AI)-related applications for hip and knee arthroplasty has proliferated. However, meaningful advances that fundamentally transform the practice and delivery of joint arthroplasty are yet to be realized, despite the broad range of applications as we continue to search for meaningful and appropriate use of AI. AI literature in hip and knee arthroplasty between 2018 and 2021 regarding image-based analyses, value-based care, remote patient monitoring, and augmented reality was reviewed. Concerns surrounding meaningful use and appropriate methodological approaches of AI in joint arthroplasty research are summarized. Of the 233 AI-related orthopaedics articles published, 178 (76%) constituted original research, while the rest consisted of editorials or reviews. A total of 52% of original AI-related research concerns hip and knee arthroplasty (n = 92), and a narrative review is described. Three studies were externally validated. Pitfalls surrounding present-day research include conflating vernacular (“AI/machine learning”), repackaging limited registry data, prematurely releasing internally validated prediction models, appraising model architecture instead of inputted data, withholding code, and evaluating studies using antiquated regression-based guidelines. While AI has been applied to a variety of hip and knee arthroplasty applications with limited clinical impact, the future remains promising if the question is meaningful, the methodology is rigorous and transparent, the data are rich, and the model is externally validated. Simple checkpoints for meaningful AI adoption include ensuring applications focus on: administrative support over clinical evaluation and management; necessity of the advanced model; and the novelty of the question being answered. Cite this article:
The aims of this study were to determine if an increasing serum cobalt (Co) and/or chromium (Cr) concentration is correlated with a decreasing Harris Hip Score (HHS) and Hip disability and Osteoarthritis Outcome Score (HOOS) in patients who received the Articular Surface Replacement (ASR) hip resurfacing arthroplasty (HRA), and to evaluate the ten-year revision rate and show if sex, inclination angle, and Co level influenced the revision rate. A total of 62 patients with an ASR-HRA were included and monitored yearly postoperatively. At follow-up, serum Co and Cr levels were measured and the HHS and the HOOS were scored. In addition, preoperative patient and implant variables and the need for revision surgery were recorded. We used a linear mixed model to relate the serum Co and Cr levels to different patient-reported outcome measures (PROMs). For the survival analyses we used the Kaplan-Meier and Cox regression model.Aims
Methods
Factors associated with high mortality rates in geriatric hip fracture patients are frequently unmodifiable. Time to surgery, however, might be a modifiable factor of interest to optimize clinical outcomes after hip fracture surgery. This study aims to determine the influence of postponement of surgery due to non-medical reasons on clinical outcomes in acute hip fracture surgery. This observational cohort study enrolled consecutively admitted patients with a proximal femoral fracture, for which surgery was performed between 1 January 2018 and 11 January 2021 in two level II trauma teaching hospitals. Patients with medical indications to postpone surgery were excluded. A total of 1,803 patients were included, of whom 1,428 had surgery < 24 hours and 375 had surgery ≥ 24 hours after admission.Aims
Methods