Roentgen stereophotogrammetric analysis methods for determining ten causes of lengthening of a soft-tissue anterior cruciate ligament graft construct.

摘要: There are many causes of lengthening an anterior cruciate ligament soft-tissue graft construct (i.e., graftfixation devicesbone), which can lead to increase in laxity. These be due plastic deformation and/or elastic deformation. The purposes this vitro study were (1) develop the methods quantify eight (four and four plastic) associated with tibial femoral fixations using Roentgen stereophotogrammetric analysis (RSA) demonstrate usefulness these methods, (2) assess how well empirical relationship between length laxity predicts two (one one midsubstance, (3) determine tare under application a 30 N force) before force reaches zero. Markers injected into tibia, femur, six cadaveric legs whose knees reconstructed singleloop tibialis grafts. To satisfy first objective, subjected 1500 cycles at 1 4 Hz 150 transmitted knee. Based on marker 3D coordinates, equations developed for determining fixations. After load cycles, WasherLoc fixation was greatest cause average 0.80.5 mm followed by cross-pin-type 0.50.1 mm. deformations decreased averages 0.30.3 0.20.1 mm, respectively. remaining close 0. objectives, after cyclic loading, lengthened incrementally while laxity, tension measured. midsubstance predicted relationships random errors precision) 0.9 0.5 minimum reached zero 5 Hence, each determined RSA as long overall does not exceed However, predicting is prone large errors. DOI: 10.1115/1.2904897