Component In Hip Arthroplasty Research Articles

Functional Acetabular Component Positioning During Direct Anterior Approach Hip Arthroplasty Using a Novel Three-Dimensional Virtual Mesh Imaging System With Fluoroscopy

BackgroundOptimal position of total hip arthroplasty (THA) components is critical for joint mechanics and stability. Acetabular component positioning during supine surgery in direct anterior approach (DAA) THA may be different in the standing position postoperatively, which traditional fluoroscopy is unable to predict. A novel 3-dimensional (3D) image analysis technology (IAT) that uses artificial intelligence to measure the tilt and rotation of the pelvis has enabled prediction of component positioning from supine to standing. The purpose of this study was to compare intraoperative fluoroscopy, non–3D-IAT, and 3D-IAT with postoperative standing radiographs to assess the accuracy of component positioning. MethodsFrom 2022 to 2023, 30 consecutive patients (86.6% women, mean age 59 [range, 55 to 67]) undergoing primary DAA THA with the use of the 3D-IAT were identified. A separate cohort of 148 patients from 2020 to 2021 (85% women, mean age 65 [range, 55 to 69]) who underwent DAA THA with non–3D-IAT was used for comparison. Leg length discrepancy (LLD), cup anteversion, and inclination were manually measured on intraoperative fluoroscopic images and digitally measured using IAT. Follow-up evaluation occurred at 1 month with standing pelvis radiographs measured using Ein Bild Röntgen Analyze–Cup software. Measurements were compared via Wilcoxon signed rank tests where P ≤ .05 indicates significantly different measurements. ResultsMedian LLD, inclination, and anteversion measurements via non–3D-IAT and fluoroscopy were significantly different compared to postoperative standing radiographs (P < .001). The 3D-IAT more accurately predicted LLD, abduction, and anteversion, with values not significantly different from postoperative standing measurements (P = .23, P = .93, and P = .36, respectively). ConclusionsThe use of the 3D-IAT during DAA THA allowed for the more accurate prediction of acetabular component position in the standing position postoperatively.

Patient-Specific Instrumentation with Laser-Guide-Navigated THA: Clinical and CT Evaluation of the First 100 Cases

Obtaining a proper position for total hip arthroplasty components is a crucial aspect of implant performance and consequently of patient outcomes. Restoring the original hip center and maintaining the limb length are key factors in reaching the optimal implant positioning. The aim of this study was to assess the accuracy and safety of a computed dynamic analysis system that, through patient-specific guides, tries to improve implant positioning and functional orientation according to patients’ spinopelvic mobility and anatomy. A total of 100 consecutive patients were prospectively enrolled. All patients received an Optimized Positioning System dynamic hip preoperative planning schedule. A CT scan protocol follow-up analysis was performed 6 months after surgery. The mean deviations from the planned acetabular inclination and anteversion were 4.3° and 3.8°, respectively. In total, 98% of cases were within ± 10° of the Lewinnek safe zone, both for inclination and anteversion. The height of osteotomy deviated, on average, 1.6 mm. In total, 100% of cases were included within 4 mm of osteotomy. Patient-specific and laser-guided instrumentation was found to be safe and accurately reproduced dynamic planning in terms of the component orientation, osteotomy level, leg length and offset.

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.

The role of patient surgical positioning on hip arthroplasty component placement and clinical outcomes: a systematic re-view and meta-analysis.

Total Hip Arthroplasty (THA) may be performed through various approaches; however, depending on the surgical position of the patient, the superiority of lateral or supine position is still debated. The aim of this systematic review and meta-analysis was to compare the supine versus lateral position in THA in terms of intraoperative and postoperative outcomes and component placement. The systematic literature search was performed by the use of Cochrane Central, Pub-Med-Medline, and Google Scholar in order to select studies that evaluated clinical outcomes and the outliers of cup alignment for inclination and anteversion between supine and lateral position for hip arthroplasty. Finally, 9 articles were included in this review. The meta-analysis showed no significant differences between the two groups for clinical outcomes, unless for blood loss and VAS (respectively p = 0.05 and p = 0.004 in favour of lateral decubitus). Regarding the number of outliers, the supine decubitus showed significant differences only for the cup anteversion (p = 0.01). However, more prospective studies with a longer follow-up that analyze both clinical and radiological parameters are needed to assess the superiority of supine or lateral patient position for total hip arthroplasty.

Clinical outcome of Bioball universal adapter in revision hip arthroplasty

BackgroundRemoval of a well-fixed uncemented femoral component in revision hip arthroplasty is challenging. A modular head–neck adapter provides an option to optimise the femoral offset and anteversion, avoiding the need for femoral stem revision. AimTo present the clinical results following revision arthroplasty with the Bioball head-neck adapter in the elderly American Society of Anaesthesiologists (ASA) Grade II, III & IV patients. Materials and methodsA retrospective review of our database was performed, and all patients classed as ASA grades II, III, & IV treated with the Bioball Universal Adapter (BUA) for 10 years were included. The indication for revision, stem retention, type of adapter, and head size were identified. Patients were contacted by a research nurse to assess the Forgotten Joint Score (FJS), the Oxford Hip Score (OHS), and any symptoms of instability at a minimum of one year post revision surgery. ResultsOur study included 47 patients. 5 (10.6%) were ASA II, 19 (40.4%) were ASA III and 23 (49%) were ASA IV. The mean age was 74 years. The mean follow up was 52 months ± 28.4 SD. The median FJS was 86 ± 11.6 SD. The median OHS was 43 ± 6.2 SD. One patient (2.1%) developed recurrent dislocation following lumbar spinal fusion. None of the other patients experienced instability. The survival rate for the adapter was 98%. ConclusionThe BUA gives good clinical outcomes with very low post revision instability. It is a valuable option for the elderly because it avoids the morbidity and risks associated with the removal of a well-fixed femoral stem. Level of EvidenceLevel IV

Custom-made 3D-printed porous metal acetabular composite component in revision hip arthroplasty with Paprosky type III acetabular defects: A case report.

Increases in the numbers of surgical procedures for primary total hip arthroplasty (THA) inevitably lead to increases in the requirements for revision THA. The achievement of long-term stability is difficult or impossible by conventional implants in patients with severe destruction of the acetabulum. This case report presents a successful treatment using a specific three-dimensional (3D)-printed porous titanium acetabular composite component without a flange in the management of Paprosky type IIIB acetabular defects. A 65-year-old female diagnosed with right hip prosthetic loosening with a huge acetabular defect presented to our hospital. We designed the 3D model of the pelvis and created an individualized 3D-printed porous titanium acetabular composite component for revision THA. The procedure was performed through a posterolateral approach, and the component was implanted in the defect and fixed with cup screws using the drill guides. At the last follow-up at 2years, the patient had a satisfactory hip joint function and no signs of loosening or other complications were found. The 3D-printed porous titanium acetabular composite component without a flange is showing promising clinical and radiological outcomes in the management of Paprosky type III acetabular defects.

Midterm Outcomes of a Monoblock Dual-Mobility Cup Cemented into a Fully Porous Acetabular Component in Revision Total Hip Arthroplasty

AbstractUtilization of dual-mobility (DM) constructs has been a promising management option to address the risk of hip instability after complex revision total hip arthroplasty (rTHA). The aim of this study is to report a minimum 2-year outcome and survivorship of a monoblock DM cup cemented in a fully porous acetabular shell in complex acetabular rTHA cases. A retrospective review of 76 patients who underwent rTHA with a novel construct that utilized an inner DM cup cemented into a fully porous outer acetabular metal shell was conducted. Demographics, radiographic, and clinical outcomes such as readmissions, dislocation, and revisions were collected. Survivorship was analyzed by the Kaplan–Meier (KM) method. Thirty cases with a minimum of 2-year follow-up were included. Patients were, on average, 65.17 ± 10.26 years old with a mean body mass index of 28.55 ± 6.33 kg/m2. Seven patients (23.3%) required reoperations. Four patients underwent acetabular revision (periprosthetic joint infection: n = 2 [6.7%]; dislocation: n = 1 [3.3%]; aseptic loosening [fully porous cup]: n = 1[3.3%]). Three patients underwent reoperation without acetabular implant revision (debridement, antibiotics, and implant retention for prosthetic joint infection: n = 2 [6.7%]; femoral periprosthetic fracture: n = 1 [3.3%]). KM survivorship analysis of all-cause acetabular revision showed survival rates of 96.7% at 6 months, 93.3% at 1 year, and 89.7% at 2 years. KM survivorship of aseptic acetabular revision showed rates of 96.7% at 1 year and 92.9% at 2 years. KM analysis of acetabular cup fixation showed rates of 100% at 1 year and 96.2% at 2 years. The rate of dislocation in our cohort was 3.3% (1 out of 30). The use of a DM acetabular cup cemented into a fully porous acetabular revision shell in complex rTHA cases has a low risk of instability and loosening at 2 years with excellent mid-term implant survivorship. The use of this construct is a good option in patients with complex acetabular reconstruction and an elevated risk for instability. This was a retrospective cohort study with a level III evidence.

Analysis of Heat Treatment Results of Ti6Al7Nb for Application as Total Hip Arthroplasty Component Material

This research is a literature study on Ti-6Al-7Nb material after having heat treatment. This study aims to analyze the results of selected articles reporting the effect of Ti-6Al-7Nb heat treatment. The research method used in this literature study is a qualitative descriptive method. Only several article results from analyses were reviewed that meet the requirement for implementation for future research topics related to materials for total hip arthroplasty. Data sources are obtained through library research techniques (literature study), which refers mainly to online sources, such as scientific journals, websites, and news from trusted sources. The results concluded that materials preparation techniques, heat treatment methods, and results analysis reported in those articles should be appropriate in this paper review. It was suggested from the literature that we need to anticipate that the martensitic phase does not cause significant changes in the Titanium alloys' properties. Moreover, the heat treatment method for α-type Titanium alloys is ineffective; namely, the heat treatment of Titanium alloys is mainly used for α+β-type Titanium alloys. The heat treatment should avoid the formation of the ω phase because constructing the ω phase will make Titanium alloys brittle.

Are We Training Surgeons to Cement a Femoral Component in Hip Arthroplasty? The Trainees' Perspective.

The importance of surgical technique is widely recognized when cementing a femoral component in hip arthroplasty. Concern exists that surgeon trainees in the United States are not being adequately trained in cement technique. The purpose of this study is to describe recent trainees' perceived experience with their training in this skill. Orthopedic graduate candidates attending a national board review course were polled with an anonymous 15-question survey regarding their experiences during training with cemented femoral components. Means and standard deviations were calculated for Likert scale questions, and univariate statistics were used to compare answers for select questions. A total of 152 surveys were completed. Ninety percent of respondents anticipated that they would be performing hemiarthroplasty for fracture in their future practice, 99% of whom anticipated using cement for stem fixation in at least some of these cases. Only a minority of respondents planned further training in an adult reconstruction fellowship (21%). Only 37% of residents perceived their training in cement technique to be comprehensive or very comprehensive, with 17% reporting that their training was inadequate or nonexistent. Forty percent reported being less than satisfied with their training. Although 96% of residents felt prepared to implant a cementless femoral component, only 82% felt adequately trained to properly cement a femoral implant. Feeling prepared to perform a well done cemented femoral stem correlated with higher percentage of cemented stems in training and higher satisfaction with training (both P= .001). Although most trainees feel prepared to cement a femoral component, many young surgeons do not perceive that they are receiving adequate training in femoral cement technique.

Intraoperative Imaging Improves Posterolateral THA Accuracy with Increased Time Cost

AbstractIntraoperative imaging may improve total hip arthroplasty (THA) component placement, but the time and cost associated with this approach have not been well described. We assessed component placement accuracy, operative time, and operating room (OR) charges for 270 patients undergoing posterolateral THA (PL-THA) with or without intraoperative imaging. This study retrospectively compared 135 PL-THA performed with intraoperative digital radiography (group PLxr) and a contemporary cohort of 135 PL-THA performed without imaging (group PL). Postoperative radiographs were evaluated to determine outlier rates for acetabular inclination of 55 degrees or higher, anteversion less than 15 or more than 40 degrees, and leg length or offset differences more than 10 mm. Surgical procedure time was extracted from hospital OR records, and procedural costs were estimated from facility charges associated with 30-minute OR time blocks and intraoperative imaging. Group PLxr had significantly fewer outliers for acetabular inclination more than 50 degrees (5.2 vs. 21.5%, p &lt; 0.001), acetabular inclination of 55 degrees or higher (0.7 vs. 8.1%, p = 0.01), acetabular anteversion less than 15 or more than 40 degrees (14.8 vs. 28.9%, p &lt; 0.01), leg length difference more than 10 mm (2.2 vs. 10.4%, p = 0.01), and femoral offset difference more than 10 mm (1.5 vs. 9.6%, p &lt; 0.01). The difference in component inclination less than 30 degrees was not significant (0.0 vs. 2.2%, p = 0.24). Intraoperative component adjustment occurred in 26 cases (21.5%), was associated with a 19-minute mean increase in operative time (p &lt; 0.001) and $1,504 mean increase in facility charges compared with nonimaged cases. Imaged cases without component adjustment increased mean operative time by 9.4 minutes (p &lt; 0.001) and mean operative charges by $766. Intraoperative imaging improves component placement accuracy during PL-THA and significantly reduces component placement outliers, particularly with respect to acetabular component inclination, femoral length, and femoral offset. Level of Evidence Level III, case-control study.

Metallosis following hip arthroplasty: two case\xa0reports

BackgroundThere has been increasing recognition of local and systemic adverse events associated with the release of metal ions and nanoparticles from hip arthroplasty components. Adverse local tissue reactions to metal ion debris can include periprosthetic solid and cystic masses known as pseudotumors. These masses can result in pain, swelling, extensive destruction to surrounding hip soft-tissues, and compression syndromes on neurovascular, gastrointestinal, and genitourinary structures. As reports of pseudotumors requiring multidisciplinary excision are limited, we present two pseudotumor cases that were excised through a combined approach.Case presentationsThe first case involves a 60-year-old Caucasian female with a large pseudotumor with intrapelvic and vascular involvement associated with a metal-on-polyethylene total hip arthroplasty, excised with contributions from general surgery, vascular surgery, and orthopedic surgery. Pseudotumor excision was followed by a revision total hip reconstruction in addition to an abductor mechanism reconstruction with tendo-Achilles allograft. The second case is that of a 64-year-old Caucasian female with a pseudotumor in close relationship to the femoral vessels following a metal-on-metal hip resurfacing, excised with a combination of vascular surgery and orthopedic surgery, with subsequent revision total hip reconstruction.ConclusionsThere remains a lack of literature to support the extensiveness of pseudotumor excision required in complex cases with significant intrapelvic or vascular involvement. Given the potential for significant adverse effects of large masses, the authors’ preference is to involve a multidisciplinary team to achieve a more comprehensive excision while minimizing the risk of potential complications.

Demographic Data Reliably Predicts Total Hip Arthroplasty Component Size

BackgroundPreoperative radiographic templating for total hip arthroplasty (THA) has been shown to be inaccurate, although essential for streamlining operating room efficiency. Although demographic data have shown to predict total knee arthroplasty component sizes, the unique contour and design among femoral stem implants have limited a similar application for hip arthroplasty. The purpose of this study was to determine whether demographic data may predict cementless THA size independent of the stem design. MethodsA consecutive series of 1,653 index cementless metaphyseal-fitting THAs were reviewed between 2007 and 2019. This included 12 unique femoral component designs, 6 acetabular component designs, 60 femur size-design combinations, and 23 acetabular size-design combinations. Implanted component sizes and patient demographic data were collected, including gender, height, weight, laterality, age, race, and ethnicity. Multivariate linear regressions were formulated to predict implanted femur and acetabular component sizes from the demographic data. ResultsThere was a significant linear correlation between gender, implant model, age, height, and weight for femur (R2 = 0.778; P < .001) and acetabular (R2 = 0.491; P < .001) sizes. Calculated femur and acetabular component sizes averaged within 0.97 and 0.95 sizes of those implants, respectively. Femur and acetabular sizes were predicted within 1 size 79.1% and 78.2% and within 2 sizes 94.3% and 94.6% of the time, respectively. ConclusionsMultivariate regression models were created based on specific demographics data to predict femur and acetabular component sizes. The model allows for simplified preoperative planning and potential cost savings implementation. A free phone application named EasyTJA was constructed for ease of implementation.

Posterior pelvic tilt evolution in patients undergoing total hip arthroplasty. A minimum 5-years follow-up clinico-radiological study

Background and objectivePelvic tilt influences the relative position between total hip arthroplasty (THA) components. Changes in lumbar spine over time may affect clinical and radiological outcomes of THA during follow-up. We assessed the evolution of pelvic tilt and cup position after THA for a minimum follow-up of five years and the possible appearance of complications. Matherial and methodsThis retrospective study includes 48 patients operated between 2008 and 2012. Clinical data, complication and radiological analysis included sacro-femoral-pubic and acetabular abduction angles on the anteroposterior pelvic view; and cup anteversion angle on the lateral cross-table hip view according to Woo and Morrey. All assessments were done pre-operatively and at 6 weeks, one, two and five years post-operatively. ResultsMean sacro-femoral-pubic decreased from 60.6° preoperatively to 58.8° at five years (p > .05), more in females (from 63.3 to 59.3) than males (58.7 to 58.3). Acetabular abduction increased from 47.3 at six-week postoperatively to 48.2 at five years (p > .05) and acetabular anteversion varied from 24.3° to 36.1° (p < .04). There were four dislocations: one late recurrent dislocation which required cup revision. ConclusionDespite the sacro-femoral-pubic angle tendency to decrease and anteversion tendency to increase after five years, larger studies with longer follow-up are needed to confirm the potential increasing in long term complications.

Evolución de la inclinación pélvica a lo largo del tiempo en pacientes intervenidos de prótesis total de cadera. Estudio clínico-radiológico con un seguimiento mínimo de cinco años

Background and objectivePelvic tilt influences the relative position between total hip arthroplasty (THA) components. Changes in lumbar spine over time may affect clinical and radiological outcomes of THA during follow-up. We assessed the evolution of pelvic tilt and cup position after THA for a minimum follow-up of five years and the possible appearance of complications. Material and methodsThis retrospective study includes 48 patients operated between 2008 and 2012. Clinical data, complication and radiological analysis included sacro-femoral-pubic and acetabular abduction angles on the anteroposterior pelvic view; and cup anteversion angle on the lateral cross-table hip view according to Woo and Morrey. All assessments were done pre-operatively and at 6 weeks, one, two and five years post-operatively. ResultsMean sacro-femoral-pubic decreased from 60.6∘ preoperatively to 58.8∘ at five years (p > .05), more in females (from 63.3 to 59.3) than males (58.7 to 58.3). Acetabular abduction increased from 47.3 at six-week postoperatively to 48.2 at five years (p > .05) and acetabular anteversion varied from 24.3∘ to 36.1∘ (p < .04). There were four dislocations: one late recurrent dislocation which required cup revision. ConclusionDespite the sacro-femoral-pubic angle tendency to decrease and anteversion tendency to increase after five years, larger studies with longer follow-up are needed to confirm the potential increasing in long term complications.

Multilayer Watertight Closure to Address Adverse Events From Primary Total Knee and Hip Arthroplasty: A Systematic Review of Wound Closure Methods by Tissue Layer.

BackgroundWound closure is a key, and often underrecognized, component of hip and knee arthroplasty. Methods for wound closure are an important consideration to better avoid wound-related adverse events; however, there is a lack of consensus on optimal methods. The objective of the following review was twofold: to characterize the wound closure methods used by layer in the total knee arthroplasty and total hip arthroplasty literature and summarize optimal wound-healing strategies to address the risk of adverse events.MethodsA systematic literature review was performed to identify total knee arthroplasty and total hip arthroplasty randomized controlled trials and nonrandomized studies reporting wound closure methods by layer and wound-healing adverse events (including superficial, deep, or periprosthetic joint infections, wound dehiscence, or prolonged wound drainage). Studies on revision procedures were excluded. Wound closure methods and adverse events were summarized qualitatively as meta-analyses were not possible because of study heterogeneity.ResultsForty studies met the inclusion criteria: 22 randomized controlled trials and 18 observational studies. Across studies, 6 categories and 22 unique techniques for closure were identified. Conventional closure methods exhibited large ranges of adverse event rates. Studies of multilayer barbed sutures with topical skin adhesives and polyester mesh or multilayer antimicrobial sutures reported narrow ranges of adverse events rates.ConclusionsConsiderable variability exists for wound closure methods, with a wide range reported in adverse events. Recent technologies and methods for standardized watertight, multilayer closure show promise for avoiding adverse events and unnecessary health-care costs; however, higher quality, comparative studies are required to enable future meta-analyses.Level of EvidenceTherapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Accuracy of Patient-Specific Instrumentation with Laser Guidance in a Dynamic Total Hip Arthroplasty: A Radiological Evaluation.

The functional positioning of components in a total hip arthroplasty (THA) and its relationship with individual lumbopelvic kinematics and a patient’s anatomy are being extensively studied. Patient-specific kinematic planning could be a game-changer; however, it should be accurately delivered intraoperatively. The main purpose of this study was to verify the reliability and accuracy of a patient-specific instrumentation (PSI) and laser-guided technique to replicate preoperative dynamic planning. Thirty-six patients were prospectively enrolled and received dynamic hip preoperative planning based on three functional lateral spinopelvic X-rays and a low dose CT scan. Three-dimensional (3D) printed PSI guides and laser-guided instrumentation were used intraoperatively. The orientation of the components, osteotomy level and change in hip length and offset were measured on postoperative CT scans and compared with the planned preoperative values. The length of surgery was compared with that of a matched group of thirty-six patients who underwent a conventional THA. The mean absolute deviation from the planned inclination and anteversion was 3.9° and 4.4°, respectively. In 92% of cases, both the inclination and anteversion were within +/− 10° of the planned values. Regarding the osteotomy level, offset change and limb length change, the mean deviation was, respectively, 1.6 mm, 2.6 mm and 2 mm. No statistically significant difference was detected when comparing the planned values with the achieved values. The mean surgical time was 71.4 min in the PSI group and 60.4 min in the conventional THA group (p < 0.05). Patient-specific and laser-guided instrumentation is safe and accurately reproduces dynamic planning in terms of the orientation of the components, osteotomy level, leg length and offset. Moreover, the increase in surgical time is negligible.

A Simple Technique to Remove Well Fixed Porous Cementless Acetabular Component in Revision Total Hip Arthroplasty

Removing well-fixed porous cementless acetabular components in revision Total Hip arthroplasty can be a surgical challenge for Orthopaedic surgeons. Forceful removal can result in loss of bone stock. Acetabular wall fracture is a real risk associated with extracting well-fixed cementless acetabular components, especially with certain instruments. Extraction of a well-fixed porous cementless acetabular component with relative ease can be achieved with the technique described.

Utility of Intraoperative Fluoroscopic Positioning of Total Hip Arthroplasty Components Using a Posterior and Direct Anterior Approach.

Positioning of implant components for total hip arthroplasty (THA) is important for polyethylene liner wear, prosthesis joint stability, and range of motion. The introduction of fluoroscopy for the direct anterior approach has been shown to improve physician accuracy for component positioning. Few studies compare the use of intraoperative fluoroscopy for THA component positioning in posterior THA. The purpose of this project is to retrospectively evaluate the effect of intraoperative fluoroscopy on component positioning for THA using posterior and direct anterior approach (DAA). A retrospective review of postoperative weight-bearing X-ray films of THAs was performed over a 2-year period where a single fellowship-trained total joint surgeon introduced direct anterior approach into his practice while expanding the intraoperative use of fluoroscopy for all THA procedures, regardless of approach. Component position was evaluated through radiographic measurement of acetabular cup inclination (goal of 40 degrees), limb length discrepancy (goal of 0 mm), and femoral component offset difference (goal of 0 mm). Radiographic analysis was performed by two independent providers. Statistical analysis was performed using Student's t-tests. A total of 107 patients with an average age of 62 years were identified during the 2-year period surrounding the THA practice change, adding fluoroscopy to posterior and DAA THA. Three cohorts were identified: cohort A: 44 patients who underwent posterior THAs without the use of intraoperative fluoroscopy, cohort B: 35 patients who underwent direct anterior approach THAs with the use of intraoperative fluoroscopy, and cohort C: 18 patients who underwent posterior THAs with the use of intraoperative fluoroscopy. The use of intraoperative fluoroscopy for the posterior approach versus unguided posterior approach increased accuracy of both cup inclination (44 degrees vs 50 degrees, P < .05) and femoral offset (4 mm vs 7 mm, P < .05). A comparison of DAA with fluoroscopy versus posterior approach without fluoroscopy showed improvement in cup inclination (48 degrees vs 50 degrees, P < .05). Fluoroscopy with posterior approach versus fluoroscopy with DAA was found to have improved cup inclination (44 degrees vs 48 degrees, P < .05). Intraoperative use of fluoroscopy can improve component positioning for posterior THA.

Custom Triflange Acetabular Components for Revision Hip Arthroplasty in the Patients with Severe Acetabular Defects: Planning, Surgical Technique, Outcomes

Employment of custom triflange acetabular components (CTAC) is one of the few options for pelvic reconstruction in the patients requiring complex acetabulum revisions with Paprosky 2 C, 3 A and 3 B defects and pelvic ring disruption.The purpose of the study was to describe the features of planning, surgical technique, and short-term treatment outcomes of the patients with significant acetabular defects, in which the revision hip arthroplasty was performed using the CTAC.Materials and Methods. A single-center analysis of a series of consecutive patients was performed: 50 complex acetabulum revisions in 47 patients (16 men and 31 women). The average age of the patients was 60±12 years (from 31 to 82; Me 62 years), the average body mass index was 29.7±6.3 kg/m2 (18.4 to 46.3; Me 29.0 kg/m).Results. The mean follow-up was 22±13 months (from 3 to 3.6 years; Me 20 months). The average Harris score increased from 27±7 (from 15 to 39; Me 27) before surgery to 64±16 (from 22 to 90; Me 67) a year after (p0.001). The level of pain according to VAS before surgery was 7±1 points (from 5 to 9; Me 7), after treatment it decreased to 2±1 points (from 0 to 7; Me 1, p0.001). In 17 cases out of 50 (34%), there was at least one complication: dislocations — 7 (14%) cases; infection — 3 (6%); loosening — 2 (4%); complications associated with the femoral component — 4 (8%), including 3 intraoperative fractures and 1 postoperative, associated with loosening of the implant; pronounced disturbances of static and locomotor functions — 2 (4%). 12 cases out of 50 (24%) required another surgery, all of which were performed in a year. The Kaplan-Meyer survival rate for the hip implants was 0.71, for the CTAC — 0.87.Conclusion. Employment of the CTAC for revision hip arthroplasty in the patients with significant acetabulum defects and pelvic ring disruption allows reliable fixation of the endoprosthesis components. The STAC placement technique is more anatomical than use of structural allografts, several augments or sup-cage systems. It allows reconstruction of extensive bone defects, theoretically avoiding the long-term problems with allografts, modular trabecular components, antiprotrusion systems and cup-cage. Although, to prove this, the longer follow-up is needed.

Dimensional analysis of 3D-printed acetabular cups for hip arthroplasty using X-ray microcomputed tomography

PurposeThree-dimensional (3D) printing is increasingly used to produce orthopaedic components for hip arthroplasty, such as acetabular cups, which show complex lattice porous structures and shapes. However, limitations on the quality of the final implants are present; thus, investigations are needed to ensure adequate quality and patients safety. X-ray microcomputed tomography (micro-CT) has been recognised to be the most suitable method to evaluate the complexity of 3D-printed parts. The purpose of this study was to assess the reliability of a micro-CT analysis method comparing it with reference systems, such as coordinate measuring machine and electron microscopy.Design/methodology/approach3D-printed acetabular components for hip arthroplasty (n = 2) were investigated. Dimensions related to the dense and porous regions of the samples were measured. The micro-CT scanning parameters (voltage – kV, current – µA) were optimised selecting six combinations of beam voltage and current.FindingsMicro-CT showed good correlation and agreement with both coordinate measuring machine and scanning electron microscopy when optimal scanning parameters were selected (130 kV – 100 µA to 180 kV – 80 µA). Mean discrepancies of 50 µm (± 300) and 20 µm (± 60) were found between the techniques for dense and porous dimensions. Investigation method such as micro-CT imaging may help to better understand the impact of 3D printing manufacturing technology on the properties of orthopaedic implants.Originality/valueThe optimisation of the scanning parameters and the validation of this method with reference techniques may guide further analysis of similar orthopaedic components.