Calibration and application of an intra-articular force transducer for the measurement of patellar tendon graft forces: an in situ evaluation.

摘要: The objective of this study was to evaluate two calibration methods for the "Arthroscopically Implantable Force Probe" (AIFP) that are potentially suitable in vivo use: (1) a direct, experimentally based method performed by applying tensile load directly graft after it is harvested but prior implantation (the "pre-implantation" technique), and (2) an indirect utilizes cadaver-based analytical expressions transform AIFP output versus anterior shear relationship, which may be established vivo, resultant "post-implantation" technique). outputs during loading knee joint using these were compared force measurements ligament cutting protocol 6 DOF cell. mean percent error (actual-measured)/(actual)* 100) associated with pre-implantation ranged between 85 175 percent, dependent on flexion angle tested. post-implantation technique evaluated ranges: loads less than 40 N, greater N. For values errors inherent 20 29 depending Below substantially greater. Of evaluated, approach provided better estimate ACL technique. However, still high suggested caution should employed when implantable probes measurement forces.