tailieunhanh - Phẫu thuật chỉnh hình

Tiến sĩ Morgan IS Quyền giảng, Khoa Chỉnh hình và Thể thao Y học, Đại học Trung tâm Y khoa Washington, Seattle, WA. Tiến sĩ Battista IS Trợ lý Giám đốc chương trình Phẫu thuật chỉnh hình ở của Chương trình, William Beaumont Quân đội Trung tâm y tế, El Paso, TX. Tiến sĩ Leopold IS Phó Giáo sư, Khoa Chỉnh hình và Thể thao Y học | Constraint in Primary Total Knee Arthroplasty Hannah Morgan MD Vincent Battista MD and Seth S. Leopold MD Dr. Morgan is Acting Instructor Department of Orthopaedics and Sports Medicine University of Washington Medical Center Seattle WA. Dr. Battista is Assistant Program Director Orthopaedic Surgery Residency Program William Beaumont Army Medical Center El Paso TX. Dr. Leopold is Associate Professor Department of Orthopaedics and Sports Medicine University of Washington Medical Center. The views expressed in this manuscript are those of the authors and do not reflect the official policy of the Department of Defense or the United States Government. Reprint requests Dr. Seth S. Leopold University of Washington Medical Center 1959 NE Pacific Street Box 356500 Seattle WA 98195. J Am Acad Orthop Surg 2005 13 515-524 Copyright 2005 by the American Academy of Orthopaedic Surgeons. Abstract Instability is an important cause of failure following total knee arthroplasty. Increasing component constraint may reduce instability but doing so also can cause increased forces to be transmitted to fixation and implant interfaces which may lead to premature aseptic loosening. Constraint is defined as the effect of the elements of knee implant design that provides the stability needed to counteract forces about the knee after arthroplasty in the presence of a deficient soft-tissue envelope. Determining the amount of constraint necessary can be challenging. Most primary total knee arthroplasties are performed for knees without substantial deformity or the need for difficult ligament balancing in these cases either a posterior-stabilized or a posterior cruciate-retaining design is appropriate. In certain situations such as patients with prior patellectomies rheumatoid arthritis or substantial preoperative deformities a posterior-stabilized knee may be favored. With their large posts varus-valgus constrained implants typically are reserved for patients with substantial coronal plane .