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Patella tendon

Daniel John Cleather
The patella is traditionally understood to be a "joint spacer" that increases the moment arm of the patellar tendon. This characterisation is unsatisfactory as it fails to explain the more interesting characteristics of the patella: 1) that the changing pivot point of the patella causes the ratio of quadriceps to patellar tendon force to almost double as the knee flexes; 2) that the patellar tendon exerts an anteriorly directed force on the tibia when the knee is extended but this switches to a posterior draw as the knee flexes; and 3) that the presence of the patella allows the quadriceps to exert different moments on the femur and tibia...
March 13, 2018: Journal of Theoretical Biology
Dario Graceffa, Claudio Bonifati, Viviana Lora, Pier Luigi Saraceni, Catia De Felice, Maria Sole Chimenti, Roberto Perricone, Aldo Morrone
BACKGROUND: The inflammatory involvement of the enthesis in the course of psoriasis is accompanied by structural abnormalities detectable by ultrasound. The most common of these abnormalities is the thickening of the tendon at the insertion site. AIMS: The aim of the present study was to compare the thickness of entheses of patients with psoriatic arthritis, only skin psoriasis, and healthy controls. METHODS: A cross-sectional study was conducted in a cohort of patients affected with either only skin psoriasis or psoriatic arthritis as well as in a control group...
March 16, 2018: Indian Journal of Dermatology, Venereology and Leprology
Sergio Barroso Rosa, Zaid Bahho, Kenji Doma, Kaushik Hazratwala, Peter McEwen, Varaguna Manoharan, Brent Matthews, Matthew Wilkinson
INTRODUCTION: Patella alta (PA) is one of the primary correctable risk factors for patellofemoral instability (PFI). Both an accurate diagnosis of PA and a clinically relevant target for correction are necessary for optimal treatment. An ideal test for PA should relate the position of the patella to the femur rather than tibia, should do so with the quadriceps contracted and the patellar tendon under tension and should have good sensitivity and specificity. None of the currently used radiographic tests PA meet these criteria, most of which are based on the position of the patella relative to the tibia with diagnostic cutoffs based on 2 standard deviations from the mean rather than optimal sensitivity and specificity...
March 15, 2018: European Journal of Orthopaedic Surgery & Traumatology: Orthopédie Traumatologie
Jamie S McPhee, James Cameron, Thomas Maden-Wilkinson, Mathew Piasecki, Moi Hoon Yap, David A Jones, Hans Degens
The contributions of fibre atrophy, fibre loss, in situ specific force and voluntary activation to weakness in sarcopenia remain unclear. To investigate, forty older (20 women; age 72±4yrs) and 31 younger adults (15 women, age 22±3yrs) completed measurements. The knee extensor maximal voluntary torque (MVC) was measured as well as voluntary activation, patella tendon moment arm length, muscle volume and fascicle architecture to estimate in situ specific force. Fibre cross-sectional area (FCSA), fibre numbers and connective tissue contents were also estimated from vastus lateralis biopsies...
February 26, 2018: Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
James Watson, Robert M Barker-Davies, Alexander N Bennett, Daniel T P Fong, Patrick C Wheeler, Mark Lewis, Craig Ranson
Objective: Several lower limb tendinopathy treatment modalities involve identification of pathological paratendinous or intratendinous neovascularisation to target proposed co-location of painful neoneuralisation. The ability to reliably locate and assess the degree of neovascularity is therefore clinically important. The Modified Ohberg Score (MOS) is frequently used to determine degree of neovascularity, but reliability has yet to be established among Sport and Exercise Medicine (SEM) consultants...
2018: BMJ Open Sport & Exercise Medicine
Michael Carl, Yajun Ma, Jiang Du
PURPOSE: Off-resonance saturation (ORS) is a tool which can be used in ultrashort echo time (UTE) magnetic resonance imaging to selectively reduce short T2 signals. When these ORS prepared UTE images are subtracted from a non-suppressed UTE acquisition, the short T2 signals are highlighted. The aim of this paper is to develop a theoretical ORS model and optimize short T2 contrast. THEORY: Using a theoretical model the sequence parameters such as saturation flip angle and off-resonance frequency were optimized to maximize short T2 contrast...
March 8, 2018: Magnetic Resonance Imaging
Masoud Parish, Haleh Farzin
Muscular dystrophies are considered to be a series of neuromuscular diseases with genetic causes and are characterized by progressive muscle weakness and degeneration of the skeletal muscle. The case of an adult man with Becker dystrophy referred for repair of the patella tendon tearing and patella fracture is described. He underwent successful surgery using total intravenous anesthesia without any complications.
2018: International Medical Case Reports Journal
Fateme Esfandiarpour, Constance M Lebrun, Sukhvinder Dhillon, Pierre Boulanger
Understanding of the exact cause of Patellofemoral Pain has been limited by methodological challenges to evaluate in-vivo joint motion. This study compared six degree-of-freedom patellar motion during a dynamic lunge task between individuals with patellofemoral pain and healthy individuals. Knee joints of eight females with patellofemoral pain and ten healthy females were imaged using a CT scanner in supine lying position, then by a dual-orthogonal fluoroscope while they performed a lunge. To quantify patellar motion, the three-dimensional models of the knee bones, reconstructed from CT scans, were registered on the fluoroscopy images using the Fluomotion registration software...
February 28, 2018: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
Eyad Alqasim, Abdulla Aljowder, Naji Alammari, Amani A Joudeh
A young patient presented with a progressive right knee pain and swelling that was worse on ambulation. Following appropriate investigations, he was confirmed having Ewing's sarcoma of the right patella. Two cycles of chemotherapy were initiated before he sustained a fall and a resultant pathological patellar fracture. He finally underwent a total right patellectomy and extensor mechanism reconstruction using Achilles tendon allograft in an attempt to eradicate the disease and salvage his knee extensor mechanism...
February 7, 2018: BMJ Case Reports
Azhar A Ali, Erin M Mannen, Paul J Rullkoetter, Kevin B Shelburne
Successful outcome following total knee arthroplasty (TKA) with patella resurfacing is partly determined by the restoration of patellofemoral (PF) function and recovery of the quadriceps mechanism. The current study compared two patellar TKA geometries (medialized dome and anatomic) to determine their impact on PF mechanics and quadriceps function. In-vivo, subject-specific patellar mechanics were evaluated using a sequential experimental and modeling approach. First, stereo radiography, marker-based motion capture, and force plate data were collected for TKA patients (10 dome, 10 anatomic) performing a knee extension and lunge...
February 7, 2018: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
William Cody Sessions, Matthew Herring, Walter H Truong
The extensor mechanism of the knee-consisting of the four muscles of the quadriceps, the quadriceps tendon, the patella, and the patellar ligament-is essential for lower extremity function during both standing and ambulation. The presence of articular cartilage and growing physes in the pediatric knee, coupled with the generation of significant tensile force, creates an opportunity for pathology unique to the pediatric population.Tibial tubercle fractures and patella injuries are quite rare, and even pediatric-trained orthopaedic surgeons may not be exposed to these injuries on a regular basis...
February 6, 2018: Journal of Knee Surgery
Lawrence Camarda, Emanuele Grassedonio, Domenico Albano, Massimo Galia, Massimo Midiri, Michele D'Arienzo
Background: The aim of this study is to evaluate a possible correlation between specific anthropometric parameters and sizes of knee tendons commonly used for ACL reconstruction. We hypothesized that specific clinical and radiological knee measurements could be better tendon sizes predictors than age, gender, height and weight. Materials and methods: 100 consecutive patients were enrolled and 77 patients met the inclusion criteria of the study. All patients underwent a MRI of the knee with a 1...
July 2017: Muscles, Ligaments and Tendons Journal
Sophie Regnault, Vivian R Allen, Kyle P Chadwick, John R Hutchinson
The patella ("kneecap") is a biomechanically important feature of the tendinous insertion of the knee extensor muscles, able to alter the moment arm lengths between its input and output tendons, and so modify the mechanical advantage of the knee extensor muscle. However, patellar gearing function is little-explored outside of humans, and the patella is often simplified or ignored in biomechanical models. Here, we investigate patellar gearing and kinematics in the ostrich-frequently used as an animal analogue to human bipedal locomotion and unusual in its possession of two patellae at the knee joint...
April 2017: Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology
Michael H Amini
Repair of a torn quadriceps tendon is necessary to restore the extensor mechanism of the knee. Traditional repair involves transosseous sutures tied over bone bridges on the inferior pole of the patella. Suture anchor repair has been shown to be stronger than transosseous repair and facilitates a smaller incision. Suture tape can improve the strength of the suture-tendon interface, and when combined with knotless anchors, leads to a stronger repair construct than even traditional suture anchors and surgeon-tied knots...
October 2017: Arthroscopy Techniques
Juan C Monllau, Juan I Erquicia, Maximiliano Ibañez, Pablo E Gelber, Federico Ibañez, Angel Masferrer-Pino, Xavier Pelfort
Patellar instability has been shown to be associated with different major factors. However, studies have demonstrated that soft tissue reconstructions are adequate enough to reestablish patellar constraint. In recent years, the medial patellofemoral ligament has been recognized as the primary passive restraint for lateral translation of the patella. Their reconstruction has gain popularity as the procedure is quite simple and fast. Although several surgical techniques have been described for their reconstruction, no clear consensus has been reached as to which is best...
October 2017: Arthroscopy Techniques
Ricardo Bastos Filho, Alberto Monteiro, Renato Andrade, M J S Fredrick Michael, Nuno Sevivas, Bruno Pereira, André Sarmento, João Espregueira-Mendes
Patellofemoral dysfunction, due to either a patellofemoral malalignment or patellar instability, is a complex and debilitating condition that significantly decreases the knee function. Conservative management may yield significant clinical outcomes; however, when morphologic anomalies are identified, the surgical approach should be employed. Hence, several surgical procedures have been described in the scientific literature aiming the correction of underlying extensor mechanism malalignments. Still, the rate of complications is higher than desirable...
December 2017: Arthroscopy Techniques
João Espregueira-Mendes, Renato Andrade, M J S Fredrick Michael, André Sarmento, Nuno Sevivas, Rui Rocha, Ricardo Bastos Filho
Patellar tendon ruptures can lead to significant functional deficiency of the extensor mechanism of the knee. These injuries, because of their inherent nature and associated complications, may require a complex treatment and remains a challenge for orthopaedic surgeons. Current surgical techniques present significant complications, including patellar fracture, damage to patellar articular cartilage, and abnormal patella height. This note describes a surgical technique to provide an additional reinforcement to the patellar tendon repair with a semitendinous autograft, without the necessity to perform any transosseous tunnels at the patella bone...
December 2017: Arthroscopy Techniques
Hassan Azimi, Oke Anakwenze
Medial patellofemoral ligament (MPFL) injuries are common in children and young adults. In patients with recurrent patellar dislocations with normal lower-extremity alignment, anatomic reconstruction of the MPFL has been shown to restore patellar stability. We describe a technique that creates an anatomic reconstruction using a dual docking technique into the patella. Our technique is simple and efficacious for reconstructing the MPFL without implant fixation in the patella, allowing a maximal bone-tendon interface for healing...
December 2017: Arthroscopy Techniques
Christopher Kester, Matthew T Wallace, James Jelinek, Albert Aboulafia
Gout is a common inflammatory crystal deposition disease that occurs in many joints throughout the body. Active gout is most often associated with painful synovitis causing searing joint pains, but gout can also produce large masses of space-occupying deposits called tophi. Tophi are most frequently seen in juxta-articular locations with or without bony erosion and are often misdiagnosed as degenerative joint disease. Soft tissue deposits and tendon involvement are also known manifestations of gout, but can present with indeterminate and alarming findings on imaging...
January 14, 2018: Skeletal Radiology
Roland M Biedert, Philippe M Tscholl
We systematically reviewed patella alta with respect to type of measurements, reported cutoff values, cutoff values for surgical correction, and proposed surgical techniques. Using the term patella alta, we performed a systematic literature search on PubMed. Inclusion criteria were original study or review articles, publication in peer-reviewed English-language journals between 2000 and 2017, and narrative description or measurement of human patellar height on plain radiographs or magnetic resonance imaging (MRI)...
November 2017: American Journal of Orthopedics
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