Abstract: A retractor may include one or more racks and retractor blades coupled to the respective racks via respective carriages and retractor arms. The carriages may traverse respective racks to laterally position retractor blades. The retractor blades may include tracks which the retractor arms may traverse to longitudinally position retractor blades with respect to the racks.

Abstract: A surgical instrument includes a rack, a first arm coupled to the rack, a second arm coupled to the rack, a first tower coupled to the first arm, and a second tower coupled to the second arm. The first tower comprises an upper end, a lower end, and a track between the upper end and the lower end. A channel of the first arm is configured to receive the track of the first tower and selectively position the first arm along the track of the first tower. The lower end of the first tower is configured to snap onto a pedicle screw and to disengage from the pedicle screw in response to a removal tool being inserted into the first tower.

Abstract: A valve assembly includes an upper sleeve, a lower sleeve, and a poppet contained between the upper and lower sleeve and operable between a first and second position. The poppet includes a first end, a second end, a side, a central cavity, and a hydraulic port. The second end is spaced from the first end, the side is adjacent one of the first end and the second end. The central cavity extends from the first end of the poppet towards the second end of the poppet. The hydraulic port extends from the side of the poppet into the central cavity. The hydraulic port is configured to receive hydraulic fluid at a first flow rate from the supply port and to supply hydraulic fluid to the central cavity at a second flow rate less than the first flow rate.

Abstract: Systems, methods, and apparatuses for a valve assembly are provided. The valve assembly includes an upper sleeve, a lower sleeve, and a poppet. The lower sleeve is coupled to the upper sleeve. The lower sleeve includes a bottom face, a side, a supply port, and a pilot port. The supply port extends through the side of the lower sleeve. The pilot port extends through the bottom face of the lower sleeve. The poppet is operable between a first position and a second position. The poppet is contained between the upper sleeve and the lower sleeve. The poppet includes a first end, a second end, a side, a central cavity, and a hydraulic port. The second end is spaced from the first end, the side is adjacent one of the first end and the second end. The central cavity extends from the first end of the poppet towards the second end of the poppet. The hydraulic port extends from the side of the poppet into the central cavity.