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knee alignment

Arin M Ellingson, Joseph D Mozingo, Dixon J Magnuson, Mark W Pagnano, Kristin D Zhao
Fluoroscopic imaging has become increasingly popular to investigate total knee arthroplasty kinematics non-invasively - 3D implant models are aligned with 2D image projections, and optimized via an edge-contour alignment technique. Previous studies have quantified the accuracy of this approach, however they do not always adequately address the impact of image collection parameters. A particularly sensitive parameter is the pulse width, or exposure time per frame. At longer pulse widths, more motion is captured in a single frame; this can lead to image blur and subsequent degradation to image edge quality...
October 11, 2016: Journal of Biomechanics
Lindsay V Slater, Joseph M Hart
The squat is an assessment of lower extremity alignment during movement, however there is little information regarding altered joint kinetics during poorly performed squats. The purpose of this study was to examine changes in joint kinetics and power from altered knee alignment during a squat. Thirty participants completed squats while displacing the knee medially, anteriorly, and with neutral alignment (control). Sagittal and frontal plane torques at the ankle, knee, and hip were altered in the descending and ascending phase of the squat in both the medial and anterior malaligned squat compared to the control squat...
October 12, 2016: Journal of Electromyography and Kinesiology
David Gøttsche, Thomas Lind, Thorbjørn Christiansen, Henrik M Schrøder
INTRODUCTION: Revision total knee arthroplasty with a cementless metaphyseal sleeve is suggested to be used without stem in revision total knee arthroplasty (rTKA). To the best of our knowledge, no papers investigating this have been published. The purpose of this study was to evaluate clinical outcome. METHOD: In this retrospective study, 71 patients operated with rTKA with sleeves without stem in the period 2009-2011 were identified; 63 were examined. All patients with the prosthesis still in place were invited to a medical examination including X-rays...
October 19, 2016: Archives of Orthopaedic and Trauma Surgery
Kwang-Jun Oh, Young-Bong Ko, Sagar Jaiswal, In-Cheul Whang
The purpose of this study was to compare the osteoconductivity, and absorbability of hydroxyapatite or beta-tricalcium phosphate in clinical scenario of opening wedge high tibial osteotomy Total 41 knees of 40 patients with follow up period of more than 1 year were enrolled. These patients were divided into two groups, Group I (22 knees, 21 patients) used hydroxyapatite and Group II (19 knees, 19 patients) used beta-tricalcium phosphate as a substitute in the opening gap. According to proven method, the osteoconductivity was assessed radiographically by the extent of new bone formation at osteotomy space and absorbability was evaluated by measuring the area occupied by substitute at immediate postoperative, postoperative 6 months and 1 year...
December 2016: Journal of Materials Science. Materials in Medicine
Kristine M Fischenich, Hannah M Pauly, Keith D Button, Ryan S Fajardo, Charles E DeCamp, Roger C Haut, Tammy L Haut Donahue
OBJECTIVE: The objective of this study was to monitor the progression of joint damage in two animal models of knee joint trauma using two non-invasive, clinically available imaging modalities. METHODS: A 3-T clinical magnet and micro-computed tomography was used to document changes immediately following injury (acute) and post injury (chronic) at time points of 4, 8, or 12 weeks. Joint damage was recorded at dissection and compared to the chronic MRI record. Fifteen Flemish Giant rabbits were subjected to a single tibiofemoral compressive impact (ACLF), and 18 underwent a combination of ACL and meniscal transection (mACLT)...
October 15, 2016: Osteoarthritis and Cartilage
Louis M Day, Subaraman Ramchandran, Cyrus M Jalai, Bassel G Diebo, Barthelemy Liabaud, Renaud Lafage, Themistocles Protopsaltis, Peter G Passias, Frank J Schwab, Shay Bess, Thomas J Errico, Virginie Lafage, Aaron J Buckland
STUDY DESIGN: Retrospective clinical and radiographic single-center study OBJECTIVE.: Assess simultaneous cervical spine and lower extremity compensatory changes with changes in thoracolumbar spinal alignment. SUMMARY OF BACKGROUND DATA: Full-body stereoradiographic imaging allows better understanding of reciprocal changes in cervical and lower extremity alignment in the setting of thoracolumbar malalignment. Few studies describe the simultaneous effect of alignment correction on these mechanisms...
October 17, 2016: Spine
Qing-Hang Zhang, Andrew Cossey, Jie Tong
Periprosthetic bone strain distributions in some of the typical cases of total knee replacement (TKR) were studied with regard to the selection of material, design and the alignments of tibial components to examine which conditions are more forgiving than the others to stress shielding post a TKR. Four tibial components with two implant designs (cruciate sacrificing and cruciate retaining) and material properties (metal-backed (MB) and all-polyethylene (AP)) were considered in a specimen-specific finite element tibia bone model loaded in a neutral position...
October 10, 2016: Medical Engineering & Physics
Armaghan Mahmoudian, Jaap H van Dieen, Sjoerd M Bruijn, Isabel Ac Baert, Gert S Faber, Frank P Luyten, Sabine Mp Verschueren
BACKGROUND: Varus thrust, defined as an abrupt increase of the knee varus angle during weight-bearing in gait, has been shown to be present in patients with moderate to severe knee osteoarthritis and is considered to be one of the risk factors for progression of symptomatic medial knee osteoarthritis. We evaluated the presence and magnitude of varus thrust and its relation with the Knee Adduction Moment in women with early medial knee osteoarthritis, and compared it to that in a group of controls and in a group of subjects with established medial knee osteoarthritis...
October 8, 2016: Clinical Biomechanics
J A D van der Woude, S Spruijt, B T J van Ginneken, R J van Heerwaarden
Varus deformity can be localized in the tibia, in the femur or in both. If varus deformity is localized within the femur, it is mandatory to correct it in the femur. This report presents the technique and results of a consecutive case series of lateral uniplanar and biplanar closed-wedge valgus osteotomy of the distal femur for the treatment of varus deformity of the knee. Retrospectively, fifteen patients (sixteen knees) were identified. Indications for surgery varied from unloading an osteoarthritic medial compartment to reduction to symmetrical varus leg alignment...
October 14, 2016: Strategies in Trauma and Limb Reconstruction
William Colyn, Rintje Agricola, Nele Arnout, Jan A N Verhaar, Johan Bellemans
PURPOSE: The influence of type and intensity of sports during growth on knee alignment was investigated. The second aim was to ascertain whether the distal femur or proximal tibia contribute most to knee alignment. Also, the influence of field position and leg dominancy on knee alignment in soccer players was audited. METHODS: Standardized full-leg standing digital radiographs were obtained from 100 males and 100 females on which 8 different alignment parameters were measured...
October 14, 2016: Knee Surgery, Sports Traumatology, Arthroscopy: Official Journal of the ESSKA
John A Heflin, Scott Ford, Peter Stevens
Blount's disease is commonly attributed to an intrinsic, idiopathic defect in the posteromedial proximal tibial physis resulting in progressive bowing of the leg, intoeing, and lateral knee thrust. Treatment has historically included bracing, physeal stapling, or corrective osteotomy, and was determined primarily by age at presentation. As we feel the pathology is not necessarily age dependent, we have elected to use the technique of guided growth using a lateral tension band plate to correct limb alignment as a first-line treatment in all patients presenting to our clinic as long as they had growth remaining and no evidence of a physeal bar...
October 2016: Medicine (Baltimore)
Romain Gaillard, Simone Cerciello, Sebastien Lustig, Elvire Servien, Philippe Neyret
PURPOSE: Total knee arthroplasty (TKA) malalignment may result in pain and limited range of motion. The present study assessed the influence of different surgeon's and patient's related factors on the post-operative tibial tray coronal alignment. METHODS: The charts and the x-rays of a continuous prospective series of 1417 TKAs operated upon between 1987 and 2015 were retrospectively reviewed. The long-leg AP views were performed at two months post-op and the tibial mechanical angle of the tibial tray was measured...
October 13, 2016: International Orthopaedics
Richard D Scott
Total knee arthroplasty (TKA) has evolved into a very successful procedure to relieve pain and improve function in the patient with advanced arthritis. Both short- and long-term outcomes are dependent on optimal surgical technique. In this article, I share a few of the many lessons learned over more than 40 years of experience performing TKA regarding exposure, alignment, bone preparation, correction of deformity, and prosthetic implantation.
September 2016: American Journal of Orthopedics
Shinsuke Someya, Motoki Sonohata, Shuya Ide, Satomi Nagamine, Tomonori Tajima, Masaaki Mawatari
BACKGROUND: Severe hip osteoarthritis is known to lead to secondary osteoarthritis of the knee joint. It is not clear whether contracture or a leg length discrepancy is more important in determining the knee alignment. METHODS: In this study, 48 hips in 48 patients with a unilateral completely dislocated hip (Crowe IV) were recruited. The patients were divided into two groups (Crowe IVa and IVb). The Crowe IVa group had completely dislocation with psudo-articulation, and the Crowe IVb group had completely dislocation without psudo-articulation...
2016: Open Orthopaedics Journal
Gregory C Wernecke, Ian A Harris, Bradley G Seeto, Darren B Chen, Samuel J MacDessi
[This corrects the article DOI: 10.1007/s11420-016-9491-y.].
October 2016: HSS Journal: the Musculoskeletal Journal of Hospital for Special Surgery
Ran Schwarzkopf, Erik Schnaser, Taiki Nozaki, Yasuhito Kaneko, Michael J Gillman
INTRODUCTION: Patient-specific implants and instruments (PSI) have been used in both knee and shoulder replacements due to the perceived benefits of improved surgical accuracy and efficiency. The proposed benefits of using a PSI in total hip arthroplasty (THA) are numerous and include reduction of operative time and improved mechanical and anatomical alignment leading to increased implant longevity, increased stability, and clinical outcomes. We describe a novel patient-specific instrumentation and a surgical method that may improve directed resection of acetabular bone and accurate cup placement during THA...
October 6, 2016: Surgical Technology International
Filip Jonkergouw, Florence Allé, Karim Chellaoui, Jos Vander Sloten, Dieter Vangeneugden
The performance of implant placement technologies are often evaluated based on their achieved post-operative implant alignment. Therefore accurate assessment techniques are necessary to compare pre-operatively planned implant positions with the corresponding post-operatively placed implant positions in total knee arthroplasty. This paper describes a CT based 3D measurement method for evaluation of implant positioning accuracy comparing post-operative implant position to the corresponding pre-operative planned implant position using 3D virtual models...
October 7, 2016: Medical Engineering & Physics
Oui Sik Yoo, Yong Seuk Lee, Myung Chul Lee, Jae Hong Park, Jae Won Kim, Doo Hoon Sun
BACKGROUND: After open wedge high tibial osteotomy (OWHTO), the proximal fragment resembles the anatomy of the proximal tibia that is aligned in the anterior-posterior direction and the distal fragment resembles the anatomy of the mid shaft that is aligned in the proximal-distal direction. In addition, the medial portion of the proximal fragment becomes aligned medially and the medial portion of the distal fragment, laterally, depending on the magnitude of the posterior opening gap. Therefore, there would be a mismatch between the post-correction bony surface and the previous pre-contoured plate geometry...
October 10, 2016: BMC Musculoskeletal Disorders
Hagen Hommel, Matthew P Abdel, Carsten Perka
While patient-specific instrumentation (PSI) in total knee arthroplasty (TKA) allows for transfer of the preoperative plan onto bony landmarks, the soft tissue balancing is not affected. The goals of this randomized clinical trial were to compare PSI and the measured resection technique (conventional) with PSI and the gap balancing technique. Fifty patients were randomized to TKA with conventional PSI (PSI-S) (n = 25) or to PSI with additional gap balancing (PSI-GB) (n = 25). All patients were clinically examined at 3 and 12 months postoperatively...
October 6, 2016: European Journal of Orthopaedic Surgery & Traumatology: Orthopédie Traumatologie
Kamal Deep, Frederic Picard, Joseph Baines
PURPOSE: The aim of this study was to assess the kinematics of arthritic knees prior to TKA. The hypothesis was that the arthritic knee follows distinct patterns with regard to deformity in coronal plane as it flexes from extended position. METHOD: Data from 585 consecutive arthritic knees that had undergone TKA using two non-image-based navigation systems were included in the study. Coronal plane alignment given by the femoro-tibial mechanical angle (FTMA) was recorded in extension, 30°, 60°, 90° and maximum flexion prior to making any bony cuts or ligamentous releases...
October 6, 2016: Knee Surgery, Sports Traumatology, Arthroscopy: Official Journal of the ESSKA
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