Methods for correction of spinal deformities

A method for treating spinal column shape deformation comprising:

• implanting a first fixation screw assembly to a first vertebra of a spinal column of a patient, the first fixation screw assembly having a fixation screw and a rod receiving channel with opposed channel arm extensions, the channel being movable relative to the fixation screw through a range of angles, the first fixation screw assembly having a locking device for separately locking the channel against movement relative to the fixation screw and a rod against movement in the channel;
• moving the channel relative to the fixation screw to a first position;
• with the channel in the first position, locating a spinal support rod between the channel arm extensions such that the rod is located either medially or laterally relative to the spinal column and a curvature of the rod matches a shape of a deformed spinal column of the patient when viewed along an anterior-posterior axis and matches a corrected anatomical shape of the spinal column of the patient, when viewed along the medial-lateral axis;
• moving the channel relative to the fixation screw to a second position such that the rod is located posteriorly of the spinal column;
• adjusting the locking device to lock the channel relative to the fixation screw,
• adjusting the rod relative to the channel;
• and
• adjusting the locking device to lock the rod against movement relative to the channel.

A method for treating spinal column shape deformation comprising:

• fixing a fixation screw assembly to a vertebra of a spinal column of a patient, the fixation screw assembly having a fixation screw, a rod receiving channel, and a locking device, the rod receiving channel defined by two spaced apart channel arms, a base extending between the arms, and a separable channel arm extension provided on each of the arms, the channel being movable relative to the fixation screw through a range of angles, the locking device including a first locking member for separately locking the channel against movement relative to the fixation screw and a second locking member for locking a rod against movement in the channel;
• moving the channel relative to the fixation screw to a first position;
• positioning the rod between the arm extensions while the channel is in the first position such that the rod is located medially or laterally with respect to the spinal column;
• with the rod positioned between the arm extensions, translating one or more vertebrae of the spinal column to correct a deformation of the spinal column by rotating the channel to a second position;
• locking the channel in the second position against movement relative to the head of the fixation screw;
• rotating one or more vertebrae of the spinal column to correct a deformation of the spinal column by twisting the vertebra relative to the rod;
• and
• locking the channel against rotation relative to the rod.

A method for treating spinal column shape deformation comprising:

• implanting a first fixation screw assembly to a first vertebra of a spinal column of a patient and a second fixation screw assembly to a second vertebra of the spinal column of the patient, the first fixation screw assembly and the second fixation screw assembly each having a fixation screw, a rod receiving channel with opposed channel arm extensions, the channel being movable relative to the fixation screw through a range of angles, and a locking device for separately locking the channel against movement relative to the fixation screw and a rod against movement in the channel;
• moving the channel of the first fixation screw assembly relative to its fixation screw to a first position;
• moving the channel of the second fixation screw assembly relative to its fixation screw to a second position;
• with the channels of the first and second fixation screw assemblies disposed in their respective first and second positions, locating a rod between the channel arm extensions of the first fixation screw assembly and between the channel arm extensions of the second fixation screw assembly such that the rod is located either medially or laterally relative to the spinal column and a curvature of the rod matches a shape of a deformed spinal column of the patient when viewed along an anterior-posterior axis and matches a corrected anatomical shape of the spinal column of the patient when viewed along the medial-lateral axis;
• with the rod located between the channel arm extensions of the first fixation screw assembly and between the channel arm extensions of the second fixation screw assembly, moving the channel of the first fixation screw assembly relative to its fixation screw to a third position and moving the channel of the second fixation screw assembly relative to its fixation screw to a fourth position such that the rod is located posteriorly of the spinal column, wherein movement of the channels from the first and second positions to the third and fourth positions translates one or more vertebrae of the spinal column to correct a deformation of the spinal column.