Mechanical pivot shift measurement to evaluate joints

Abstract

An unmet need of orthopedic practitioners is a clinically-relevant measurement device and technique to objectively quantify joint (e.g., knee) stability, including rotational stability. An apparatus and method is disclosed for performing a mechanical joint movement test, such as a knee pivot shift test, through the application of standardized dynamic loads (e.g., using a constant-tension spring or other mechanism). When used for knee evaluation, this test reliably induces the characteristic 'pivot' tibial subluxation/reduction event in an ACL-deficient knee, allowing for more sensitive detection of deficiencies in rotational knee stability, quantification of the relative importance of knee stabilizers, and comparison of the performance of contemporary ACL reconstruction techniques. The test allows for better understanding joint biomechanics and for defining unique kinematic and kinetic signatures for common joint injuries, such as knee injuries, that will be valuable for diagnostic purposes.