Incidence and pattern of periprosthetic hip fractures around the stem in different stem geometry.

BACKGROUND: The number of total hip arthroplasties (THA) is expected to increase worldwide; thus, complications are likely to increase at the same ratio. In this scenario, periprosthetic femoral fractures (PFFs) are an increasing concern. Identifying the predisposing factors is important in order to prevent as much as possible the risk of PFF in the future. PATIENTS AND METHODS: The purpose of this study was to correlate the risk of periprosthetic femoral fractures to the most common patients' comorbidities and stem geometry. We reviewed all THA for non-oncologic indications between 2004 and 2014 with a mean follow-up of six years (range, 2-12). Three thousand two hundred forty-eight patients (3593 implants) were enrolled in the study, and 45 PFF were registered during this time period. Two thousand five hundred seventy-seven implants (71%) were straight stems, and 1015 (28.3%) were anatomic stems. All X-rays were then analyzed and classified according to the modified Vancouver classification. RESULTS: Periprosthetic femoral fractures incidence was associated with anatomic stem geometry (p < 0.001, OR = 2.2), BMI (p < 0.001), and diabetes (p < 0.001, OR = 5.18). PFFs were not significantly associated with age, gender, and all the other variables. Fracture pattern was different between straight and anatomic stems. Clamshell fractures were more likely to occur in anatomic stems compared to straight stems (p < 0.005). CONCLUSIONS: Periprosthetic femoral fractures are highly associated with obesity and osteoporosis. Anatomic stems reported a higher incidence of PPF than straight stems. The typical fracture type for anatomical stems is the clamshell pattern, while straight stems are more likely affected by type B fractures.

Deep Learning for Automated Classification of Inferior Vena Cava Filter Types on Radiographs.

PURPOSE: To demonstrate the feasibility and evaluate the performance of a deep-learning convolutional neural network (CNN) classification model for automated identification of different types of inferior vena cava (IVC) filters on radiographs. MATERIALS AND METHODS: In total, 1,375 cropped radiographic images of 14 types of IVC filters were collected from patients enrolled in a single-center IVC filter registry, with 139 images withheld as a test set and the remainder used to train and validate the classification model. Image brightness, contrast, intensity, and rotation were varied to augment the training set. A 50-layer ResNet architecture with fixed pre-trained weights was trained using a soft margin loss over 50 epochs. The final model was evaluated on the test set. RESULTS: The CNN classification model achieved a F1 score of 0.97 (0.92-0.99) for the test set overall and of 1.00 for 10 of 14 individual filter types. Of the 139 test set images, 4 (2.9%) were misidentified, all mistaken for other filter types that appear highly similar. Heat maps elucidated salient features for each filter type that the model used for class prediction. CONCLUSIONS: A CNN classification model was successfully developed to identify 14 types of IVC filters on radiographs and demonstrated high performance. Further refinement and testing of the model is necessary before potential real-world application.

Quantitative Stent Graft Motion in ECG Gated CT by Image Registration and Segmentation: In Vitro Validation and Preliminary Clinical Results.

OBJECTIVES: The dynamic endovascular environment of stent grafts may influence long term outcome after endovascular aneurysm repair (EVAR). The sealing and fixation of a stent graft to the aortic wall is challenged at every heartbeat, yet knowledge of the cardiac induced dynamics of stent grafts is sparse. Understanding the stent-artery interaction is crucial for device development and may aid the prediction of failure in the individual patient. The aim of this work was to establish quantitative stent graft motion in multiphasic electrocardiogram (ECG) gated computed tomography (CT) by image registration and segmentation techniques. METHODS: Experimental validation was performed by evaluating a series of ECG gated CT scans of a stent graft moving at different amplitudes of displacement at different virtual heart rates using a motion generating device with synchronised ECG triggering. The methodology was further tested on clinical data of patients treated with EVAR devices with different stent graft designs. Displacement during the cardiac cycle was analysed for points on the fixating stent rings, the branches or fenestrations, and the spine. RESULTS: Errors for the amplitude of displacement measured in vitro at individual points on the wire frame were at most 0.3 mm. In situ cardiac induced displacement of the devices was found to differ per location and also depended on the type of stent graft. Displacement during the cardiac cycle was greatest in a fenestrated device and smallest in a chimney graft sac anchoring endosystem, with maximum displacement varying from 0.0 to 1.4 mm. There was no substantial displacement measurable in the spine. CONCLUSIONS: A novel methodology to quantify and visualise stent graft motion in multiphasic ECG gated CT has been validated in vitro and tested in vivo. This methodology enables further exploration of in situ motion of different stent grafts and branch stents and their interaction with native vessels.

Three-Dimensional Optical Coherence Tomography Imaging For Glaucoma Associated With Boston Keratoprosthesis Type I and II.

PRECIS: Three-dimensional (3D) spectral domain optical coherence tomography (OCT) volume scans of the optic nerve head (ONH) and the peripapillary area are useful in the management of glaucoma in patients with a type I or II Boston Keratoprosthesis (KPro). PURPOSE: The purpose of this study was to report the use of spectral domain OCT in the management of glaucoma in patients with a type I or II Boston KPro. MATERIALS AND METHODS: This study is an observational case series. Four consecutive patients with KPro implants were referred for glaucoma evaluation. A comprehensive eye examination was performed which included disc photography, visual field testing, and high-density spectral domain OCT volume scans of the ONH and the peripapillary area. 2D and 3D parameters were calculated using custom-designed segmentation algorithms developed for glaucoma management. RESULTS: Spectral domain OCT parameters provided useful information in the diagnosis and management of 4 KPro patients. OCT parameters which can be used in KPro patients included 2D retinal nerve fiber layer (RNFL) thickness, 3D peripapillary RNFL volume, 3D peripapillary retinal thickness and volume, 3D cup volume, and 3D neuroretinal rim thickness and volume. In 3 of 4 cases where the traditional 2D RNFL thickness scan was limited by artifacts, 3D spectral domain OCT volume scans provided useful quantitative objective measurements of the ONH and peripapillary region. Therefore, 3D parameters derived from high-density volume scans as well as radial scans of the ONH can be used to overcome the limitations and artifacts associated with 2D RNFL thickness scans. CONCLUSIONS: Spectral domain OCT volume scans offer the possibility to enhance the evaluation of KPro patients with glaucoma by using both 2D and 3D diagnostic parameters that are easily obtained in a clinic setting.

Innovations in Transcatheter Valve Technology: What the Next Five Years Hold.

Transcatheter aortic valve replacement is indicated for the treatment of symptomatic severe aortic stenosis in patients at intermediate or greater risk for surgery. Future indications may include low-risk patients, asymptomatic patients, bicuspid valves, moderate aortic stenosis, and pure native aortic valve regurgitation. Key hurdles to overcome include pacemaker risk, vascular injury, paravalvular regurgitation, coronary artery reaccess, durability, and embolic risk. New valve designs include synthetic polymeric valves that may allow for greater durability, in addition to advances in terms of precise positioning and repositioning to reduce the complication rate.

Paraprosthetic Complications After Endoprosthesis Replacement of Pelvis Joint with Implants.

PURPOSE: The purpose of the paper is shaping of ideas about possible ways of decreasing complications of the analyzed types of operations and identification of opportunities of the impact on the socio-economic environment among the Afro-American population of USA. The paper demonstrates that the issue of coxofemoral prosthesis is not only a purely medical but also a social problem. In particular, availability of timely aid, as well as insurance in the form of surgery, refer to relevance of the range of problems. METHODOLOGY: The experimental method was used in the study. Patients were implanted different types of endoprostheses. 90 patients were implanted customized endoprostheses, 27 patients were implanted foreign module endoprostheses. The research subject is prediction of complications after endoprosthesis replacement surgeries depending on methods, types and forms. RESULTS: As a result, we can see that available health insurance is more acceptable understanding of the need for endoprosthesis replacement. Post-operative care issues fall into the range of social policy problems. A comparative aspect of a country with general insurance and differentiated coverage among the Afro-America population appears innovative. CONCLUSIONS: In the context of the current situation it can be concluded that surgery is the last stage for already established support system of the population. For this reason, it's worth mentioning that state bodies of the U.S. should put a greater emphasis on the health care of the Afro-American population.

In-stent neoatherosclerosis and tissue characteristics of restenotic lesions following implantation of second generation drug-eluting stents in unrestricted coronary lesions: Optical frequency domain imaging study.

BACKGROUND: Differences in stent platform, polymer coatings, and antirestenotic drugs among the current in use second-generation drug-eluting stents (G2-DESs) may induce significant variations in neointimal response and vascular healing, which may impact the prevalence of neoatherosclerosis (NA) and morphological appearance of the restenotic tissue. METHODS AND RESULTS: Utilizing Optical frequency domain imaging, two independent reviewers, retrospectively compared the prevalence of neoatherosclerosis (NA), and the morphological differences, and tissue characteristics of 50 G2-DESs in-stent restenosis (ISR) lesions (35 everolimus-eluting stent [22 cobalt-chromium (CoCr), 13 platinum-chromium (PtCr)], and 15 biolimus-eluting stent [BES]) implanted liberally in unrestricted coronary lesions. More than half of the stents were implanted in type C lesions, while 40% of the stents were implanted primarily in lesions with recanalized chronic total occlusion. NA, defined as a neointima formation with the presence of lipids or calcification, was observed in fewer than half (24/50) of all ISR lesions with no significant in-between group differences (41%, 69%, and 40% in CoCr, PtCr, and BES respectively, P = 0.22), nor were there any significant differences in the morphological appearance or tissue characteristics between all G2-DESs subtypes. CONCLUSIONS: Acknowledging some limitations, our results may suggest that the prevalence of NA and the morphological appearance of restenotic lesions might not differ when G2-DESs are implanted in unrestricted, rather complex, coronary lesions.

Reverse Shoulder Arthroplasty Prosthesis Design Classification System.

Multiple different reverse total shoulder arthroplasty (rTSA) prosthesis designs are available in the global marketplace for surgeons to perform this growing procedure. Subtle differences in rTSA prosthesis design parameters have been shown to have significant biomechanical impact and clinical consequences. We propose an rTSA prosthesis design classification system to objectively identify and categorize different designs based upon their specific glenoid and humeral prosthetic characteristics for the purpose of standardizing nomenclature that will help the orthopaedic surgeon determine which combination of design configurations best suit a given clinical scenario. The impact of each prosthesis classification type on shoulder muscle length and deltoid wrapping are also described to illustrate how each prosthesis classification type impacts these biomechanical parameters.

Reduced patellofemoral and walking pain with mobile-bearing vs. fixed-bearing total knee replacements: a mid-term prospective analytic study.

OBJECTIVE: Total knee replacement (TKR) is the standard treatment for advanced stage knee osteoarthritis. The introduction of the mobile-bearing (MB) design has given rise to a series of theoretical advantages compared to fixed-bearing (FB) implants, although current literature does not reveal significant differences between the designs. The aim of this study was to estimate the clinical results of 2 cemented total knee prosthetic designs: an MB and an FB design. METHODS: A series of patients with similar clinical and radiographic characteristics were treated consecutively with 100 FB followed by 94 MB implants. Patients were evaluated radiographically and clinically. RESULTS: Statistically significant differences were found in terms of pain at 5 years in favor of MB prostheses (p=0.006). The "pain on ascending/descending stairs" category on the KSS score showed improvement at 5 years for the MB design (p=0.003). MB implants showed better results in terms of ability to ascend/descend stairs at five years (p=0.002). With regards to the patients' ability to walk, there were differences at 1 year (p=0.020) and at 5 years (p=0.021) in favor of MB implants. CONCLUSION: At a mean follow-up of 5 years, significant differences were observed in the MB prosthesis in terms of postoperative pain, ability to ascend/descend stairs, and patellofemoral pain.

Integration of surface electromyographic sensors with the transfemoral amputee socket: a comparison of four differing configurations.

BACKGROUND AND AIM: In recent years, there has been an increased interest in recording high-quality electromyographic signals from within the sockets of lower-limb amputees. However, successful recording presents major challenges to both researchers and clinicians. This article details and compares four prototypical integrated socket-sensor designs used to record electromyographic signals from within the sockets of transfemoral amputees. TECHNIQUE: Four prototypical socket-sensor configurations were constructed and tested on a single transfemoral amputee asked to perform sitting/standing, stair ascent/descent, and level ground walking. The number of large-amplitude motion artifacts generated using each prototype was quantified, the amount of skin irritation documented, and the comfort level of each assembly subjectively assessed by the amputee subject. DISCUSSION: Of the four configurations tested, the combination of a suction socket with integrated wireless surface electrodes generated the lowest number of large-amplitude motion artifacts, the least visible skin irritation, and was judged to be most comfortable by the amputee subject. CLINICAL RELEVANCE: The collection of high-quality electromyographic signals from an amputee's residual limb while maximizing patient comfort holds substantial potential to enhance neuromuscular clinical assessment and as a method of intuitive control of powered lower-limb prostheses.

Prosthetic guidelines for ocular rehabilitation in patients with phthisis bulbi: a treatment-based classification system.

Prosthetic rehabilitation of phthisis bulbi defects is the only treatment option for cosmetic rehabilitation of patients with such defects. Currently, there is no treatment-based classification for prosthetic rehabilitation of patients with phthisis bulbi. Phthisical ocular defects and/or prosthetic rehabilitation were evaluated in an attempt to establish prosthetic guidelines that could be organized into a classification system. Fifty patients who received rehabilitation for phthisis bulbi were reviewed. Phthisis bulbi defects were divided into 4 classes. All the patients had rehabilitation, depending upon the class to which they were assigned. The aim of this treatment-oriented classification system was to organize and define the complex nature of the restorative decision-making process for patients with phthisis bulbi.

A randomized trial comparing acetabular component fixation of two porous ingrowth surfaces using RSA.

Several new porous ingrowth surfaces for acetabular component fixation have recently been developed. The purpose of this study was to compare the in vivo fixation achieved by two different porosity ingrowth surfaces using radiostereometric analysis (RSA). Sixty-two patients undergoing primary total hip arthroplasty (THA) were randomized to receive a cementless acetabular component with either a 61% high porosity asymmetric titanium porous surface (StikTite, Smith and Nephew, TN, USA) or a 45% low porosity sintered bead porous surface (Roughcoat, Smith and Nephew, TN, USA). RSA and clinical follow-up examinations were done post-operatively, 6-weeks, 3-months, 6-months, 1-year and 2-years. Both the high porosity StikTite and lower porosity Roughcoat surfaces provided excellent biologic fixation.

Influence of stem design on the primary stability of megaprostheses of the proximal femur.

PURPOSE: Extended bone defects of the proximal femur can be reconstructed by megaprostheses for which aseptic loosening constitutes one of the major failure modes. The basic requirement for long-term success of endoprostheses is primary stability. We therefore assessed whether sufficient primary stability can be achieved by four different megaprostheses in a standardised bone defect of the proximal femur and whether their different design leads to different fixation patterns. METHODS: Four different designs of proximal femoral replacements were implanted into 16 Sawbones® after preparing segmental bone defects (AAOS type II). Primary rotational stability was analysed by application of a cyclic torque of ±7 Nm and measuring the relative micromotions between bone and implant at different levels. The main fixation zones and differences of fixation patterns of the stem designs were determined by an analysis of variance. RESULTS: All four implants exhibited micromotions below 150 µm, indicating adequate primary stability. Lowest micromotions for all designs were located near the femoral isthmus. The extent of primary stability and the global implant fixation pattern differed considerably and could be related to the different design concepts. CONCLUSIONS: All megaprostheses studied provided sufficient primary stability if the fixation conditions of the femoral isthmus were intact. The design characteristics of the different stems largely determined the extent of primary stability and fixation pattern. Understanding these different fixation types could help the surgeon to choose the most suitable implant if the fixation conditions in the isthmus are compromised.

Metal hypersensitivity and metal ion levels in patients with coated or uncoated total knee arthroplasty: a randomised controlled study.

PURPOSE: Metal ion release by orthopaedic implants may cause local and systemic effects and induce hypersensitivity reactions. Coated implants have been developed to prevent or reduce these effects. This study was initiated to investigate the safety of a novel coating for total knee arthroplasty (TKA) implants. METHODS: A total of 120 patients undergoing primary TKA with no history of hypersensitivity and no other metal implant were randomised to receive either a coated or uncoated implant. Chromium (Cr), cobalt (Co), molybdenum (Mb) and nickel (Ni) hypersensitivity patch testing and plasma ion concentrations were evaluated pre-operatively and one year post-operatively. RESULTS: At the one year follow-up both groups demonstrated significant improvement in knee function and quality of life. One new weakly positive reaction to Co in the TKA group with coated implant and two doubtful skin reactions to Ni (one in each group) were noted. Even with sensitisation to implant materials no skin reactions were observed. Plasma metal ion concentrations did not increase and were not elevated at the one year follow-up in either group. CONCLUSIONS: Sensitisation after TKA was rare and had no influence on clinical results. TKA with coated implant and standard TKA demonstrated no plasma metal ion elevation.

Locomotion mode classification using a wearable capacitive sensing system.

Locomotion mode classification is one of the most important aspects for the control of powered lower-limb prostheses. We propose a wearable capacitive sensing system for recognizing locomotion modes as an alternative solution to popular electromyography (EMG)-based systems, aiming to overcome drawbacks of the latter. Eight able-bodied subjects and five transtibial amputees were recruited for automatic classification of six common locomotion modes. The system measured ten channels of capacitance signals from the shank, the thigh, or both. With a phase-dependent linear discriminant analysis classifier and selected time-domain features, the system can achieve a satisfactory classification accuracy of 93.6% ±0.9% and 93.4% ±0.8% for able-bodied subjects and amputee subjects, respectively. The classification accuracy is comparable with that of EMG-based systems. More importantly, we verify that neuro-mechanical delay inherent in capacitive sensing does not affect the timeliness of classification decisions as the system, similar to EMG-based systems, can make multiple judgments during a gait cycle. Experimental results also indicate that capacitance signals from the thigh alone are sufficient for mode classification for both able-bodied and transtibial subjects. Our investigations demonstrate that capacitive sensing is a promising alternative to myoelectric sensing for real-time control of powered lower-limb prostheses.

The clinical and radiographical results of reverse total shoulder arthroplasty with eccentric glenosphere.

BACKGROUND: Scapular notching is a common worrying finding after reverse total shoulder arthroplasty (RSA). Eccentric glenospheres have recently been developed in an attempt to prevent notching. The purpose of this study was to evaluate the clinical and radiological results of RSA with an eccentric glenosphere and compare the incidence and the severity of scapular notching using a concentric glenosphere. METHODS: A prospective evaluation was performed of 57 consecutive RSA performed over a two-year period. At a minimum of two years postoperatively, 47 RSAs with a mean 30.4 months follow-up were evaluated clinically and radiographically and compared to a historical control group of concentric glenospheres performed by the same surgeon. RESULTS: The mean Constant score significantly increased (from 32.4 to 71.8) postoperatively (p < 0.0001). Active forward flexion and external rotation also significantly increased (p < 0.0001). Overall, scapular notching was present in 19 shoulders (40.4 %). Grade 1 notching was observed in 13 shoulders (27.7 %), grade 2 in five shoulders (10.6 %), grade 3 in one shoulder (2.1 %), and grade 4 in no shoulders. There was no significant difference in the incidence (p = 0.289) of notching between the eccentric and concentric glenospheres. However, the severity of notching was significantly decreased (p = 0.011) with an eccentric glenosphere. The postoperative Constant score was not significantly different between patients with or without notching (p = 0.651). CONCLUSION: A Grammont type RSA with eccentric glenosphere can result in good clinical outcomes. An eccentric glenosphere does not prevent notching, but decreases the severity of scapular notching at early follow-up.

The natural history of anterior knee pain in 2 posterior-stabilized, modular total knee arthroplasty designs.

Anterior knee pain (AKP) has been a persistent complaint after total knee arthroplasty; however, the natural course of this complaint has not been fully investigated. This is a 10-year follow-up report of a prospective, randomized study between the Insall-Burstein II (Zimmer, Warsaw, IN) and the Press Fit Condylar Modular (Johnson & Johnson, Raynham, MA) knees. Up to one third of total knee arthroplasties will experience mild to moderate AKP at 1-year follow-up, which will persist in approximately 30% of these previously symptomatic knees at 10-year follow-up. New-onset AKP will develop in approximately 10% of previously asymptomatic knees.

[Does the material of stapes prosthesis influence hearing improvement in stapes surgery--retrospective analysis of 350 cases]. / Wplyw rodzaju protezki strzemiqczka na stopien poprawy sluchu w chirurgii strzemiaczka--analiza retrospektywna 350 przypadków.

AIM: Retrospective analysis of the post-op hearing results in stapes surgery using different types of materials for stapes prosthesis after 12 months follow up. MATERIAL AND METHODS: The total number of 350 otosclerosis patients who underwent surgical treatment at the Otosurgery Department, Medical University of Lodz from 1980-2002. All patients included in the study were divided into 4 groups: group 1 (N=54)--Portmann's method interposition, group 2 (N=160)--stapes replaced with the Shea-type prosthesis, group 3 (N=60)--platinum wire prosthesis (Zini-type), group 4 (N=76)--teflon-piston operation (Fisch-type). RESULTS: The 12 months post-op mean value for air-bone gap (500, 1000, 2000 Hz) presented the following values: group 1-19 dB, group 2-15.9 dB, group 3-18.4 dB, group 4-13.5 dB. The percentage of patients with the mean air-bone gap value of 15 dB or less (500, 1000, 2000 Hz) has the following values in each group: group 1-75%, group 2-81.3%, group 3-83%, group 4-85%. CONCLUSIONS: 12 months post-op hearing results compared between the 4 studied groups showed statistically not significant differences. Our experience with teflon-piston prosthesis shows the lowest post-op mean value of the air-bone gap.

[Dislocations hip arthroplasty]. / Zwichniecia endoprotez stawów biodrowych.

The authors present analysis of dislocation following hip arthroplasty based on their own clinical material of 1985-2005 year. It contain 2712 cases of total hip arthroplasty, 2171 (80.1%) cases were cemented including 64 (2.4%) cases of revised arthroplasty, 541 (19.9%) cases were cement-free stabilized including 7 (0.2%) cases of revised arthroplasty. Obtained outcomes of analysis permit to make assertion that dislocation following hip arthroplasty occurred during first three month after surgery, more frequently in case of revised arthroplasty and following fractures of femoral neck. Requirement of success is appropriate steady of implant and right done supervision of rehabilitation with learned necessary motoric behaviors.