Abstract: A surgical apparatus is configured to support at least one bone cut for installation of a prosthetic component. The installed prosthetic component will have reduced alignment error. The surgical apparatus is configured to distract a first compartment to a first predetermined load value while allowing a moving support structure to pivot freely. A distraction lock mechanism is then engaged to prevent movement of a distraction mechanism that raises or lowers the moving support structure relative to a fixed support structure. The moving support structure has M-L tilt angle that is measured. A M-L tilt mechanism is engaged to forcibly equalize the first and second compartments. Engaging the M-L tilt mechanism prevents the moving support structure from freely pivoting. The at least one bone cut relates to the first and second compartments equalized and the M-L tilt angle.

Abstract: A measurement system for installation of a prosthetic component. The measurement system comprises a housing, a slide block, a medial plate, a lateral plate, a fixed plate, and a threaded shaft. The fixed plate couples to the housing. The threaded shaft couples to the slide block. The threaded shaft is rotated to move the slide block within the housing. The slide block includes a free wheel gear. A medial plate and a lateral plate respectively couple to a medial post and a lateral post. The medial post and lateral post each have gear teeth that is configured to couple the free wheel gear. The housing retains, aligns and supports movement of the medial and lateral post parallel to the slide block. A medial brake and a lateral brake is configured to couple to the medial post and the lateral post to prevent movement under user control.