Five human anatomic specimen knees were used to determine the effect of patellar component position on patellofemoral kinematics, contact pressures, and contact areas after total knee arthroplasty using a polyethylene, domed patellar component. Each patellar component was positioned at the anatomic center of the resected patellar surface and then repositioned 5 mm proximally, distally, medially, and laterally. Patellar tilt was greatest with medial positioning of the patellar component and least with central and lateral positioning. At higher knee flexion angles, patellofemoral joint contact pressures increased at the medial facet with the medialized component and at the lateral facet for the lateralized component. The centralized component had the most evenly balanced patellar facet contact pressures. Distally positioned patellar components resulted in decreased patellar component loading at higher knee flexion angles. Central positioning of the patellar component results in optimal patellofemoral mechanics when maximal coverage of the resected patella is desired.
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http://dx.doi.org/10.1097/00003086-199909000-00035 | DOI Listing |
J Clin Orthop Trauma
February 2025
Joints and Spine Clinic, Mahavir Nagar, Kandivali West, Mumbai, 400067, India.
Introduction: Numerous orthopaedic procedures including dynamic hip screw plating and various osteotomies require placement of a reference guide pin or K wire to direct bone cuts or for drilling screw holes. Appropriate positioning of these wires is a critical component of surgery. Irrespective of whether one is a seasoned surgeon or an apprentice, these wires often need repositioning and readjustment.
View Article and Find Full Text PDFCureus
December 2024
Clinical Research and Medical Writing, Meril Life Sciences Private Limited, Vapi, IND.
Aim The primary objective of the study was to evaluate the mid-term implant survivability, rate of revisions, and clinical and functional outcomes following patella resurfacing during total knee arthroplasty (TKA) utilizing posterior stabilized (PS) total knee system (TKS). Methods A prospective, single-arm, multi-center, post-marketing surveillance encompassed patients with end-stage primary knee osteoarthritis (OA) or inflammatory arthritis. The time points of the study included baseline, six weeks, six months, one year, and three years post-operatively.
View Article and Find Full Text PDFJ Orthop Case Rep
January 2025
Department of Orthopaedic Surgery, Maulana Azad Medical College, Bahadur Shah Marg, New Delhi, India.
Introduction: Tumoral calcinosis is a rare hereditary condition characterized by the deposition of calcium phosphate and hydroxyapatite in periarticular soft tissues. First described by Giard and Duret in 1898 and later detailed by Inclan in 1943, this condition has often been confused with other forms of periarticular calcification. Tumoral calcinosis predominantly affects young males and is typically found around major joints, such as the shoulder, elbow, hip, ankle, and wrist.
View Article and Find Full Text PDFJ Knee Surg
January 2025
Orthopaedic Surgery, Mayo Clinic, Rochester, United States.
Introduction: Historically, cementless patellar implants were fraught with issues of fixation and polyethylene wear. However, contemporary cementless patellar implants incorporate modern technologies for implant design and offer the potential for improved biological fixation and longevity. As such, an evaluation of the performance of modern cementless patellae is needed.
View Article and Find Full Text PDFJ Clin Orthop Trauma
January 2025
Loyola University Health System, Department of Orthopaedic Surgery and Rehabilitation, 2160 South First Avenue, 60153, Maywood, IL, USA.
Introduction: Mobile-bearing (MB) inserts, designed to minimize aseptic loosening and to reduce contact stresses leading to polyethylene wear, are an alternative to fixed-bearing (FB) inserts. Most studies have shown no significant difference between MB and FB constructs, and there is limited long-term data comparing the two constructs [1,2,3,4]. The purpose of this study was to report the outcomes of a randomized controlled trial comparing MB versus FB inserts on patients with minimum 20-year follow-up.
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