An unusual case of early dislocation of a mobile bearing posterior stabilized total knee arthroplasty in a 48-year-old Caucasian woman is described. Dislocation occurred one day postoperatively, attributed to a gap mi...An unusual case of early dislocation of a mobile bearing posterior stabilized total knee arthroplasty in a 48-year-old Caucasian woman is described. Dislocation occurred one day postoperatively, attributed to a gap mismatch. Revision surgery reduced posterior dislocation, increased bearing plate thickness and rebalanced ligaments. A second dislocation occurred after revision surgery. The patient’s history was retaken and a hamstring spasm disease identified. A new revision utilized a more constrained design, without perioperative local nerve block. Two years following surgery, no further dislocation had occurred. A numerical musculoskeletal model of the case and implant configuration identified no trend to mobile bearing dislocation when regular muscle forces were applied. Muscle spasm is a risk factor for mobile bearing total knee arthroplasty dislocation, especially with femoral nerve block.展开更多
文摘An unusual case of early dislocation of a mobile bearing posterior stabilized total knee arthroplasty in a 48-year-old Caucasian woman is described. Dislocation occurred one day postoperatively, attributed to a gap mismatch. Revision surgery reduced posterior dislocation, increased bearing plate thickness and rebalanced ligaments. A second dislocation occurred after revision surgery. The patient’s history was retaken and a hamstring spasm disease identified. A new revision utilized a more constrained design, without perioperative local nerve block. Two years following surgery, no further dislocation had occurred. A numerical musculoskeletal model of the case and implant configuration identified no trend to mobile bearing dislocation when regular muscle forces were applied. Muscle spasm is a risk factor for mobile bearing total knee arthroplasty dislocation, especially with femoral nerve block.
