Locking-cap module and connector

A locking-cap system, comprising:

• a locking-cap including:
• an internal circumferential surface having a first thread pattern;
• a first connecting flange and a second connecting flange opposite the first connecting flange, the first and second connecting flanges extending from a side surface of the locking-cap and defining, at least partly, a top surface of the locking-cap;
• and
• a first retaining rail and a second retaining rail opposite the first retaining rail, the first and second retaining rails extending from the side surface of the locking-cap and defining, at least partly, a bottom surface of the locking-cap;
• a set screw including an external circumferential surface having a second thread pattern, the second thread pattern corresponding in size and shape to the first thread pattern for mating with the first thread pattern;
• a connector including:
• an internal surface comprising a rod passageway and a connecting portion, the connecting portion disposed proximate an upper surface of the connector and configured to selectively couple with the locking-cap such that the locking-cap is fixed relative to the connecting portion in an engaged position, the connecting portion including:
• a first connecting channel and a second connecting channel opposite the first connecting channel, the first connecting channel being configured to connect with the first connecting flange and the second connecting channel being configured to connect with the second connecting flange;
• a third connecting channel and a fourth connecting channel opposite the third connecting channel, the third connecting channel being configured to connect with the first retaining rail and the fourth connecting channel being configured to connect with the second retaining rail;
• a surgical tool comprising a distal end with (i) a plurality of arms configured to engage with a plurality of lateral sidewalls of the connector to provide a counter-torque to the connector and (ii) with a plurality of mating rails configured to engage with a plurality of mating channels of the connector to provide counter-torque to the connector;
• and
• wherein, when the locking-cap is in the engaged position, the first connecting flange and the second connecting flange engage with the connector such that an uppermost surface of the first connecting flange and an uppermost surface of the second connecting flange are generally flush with a top surface of the connector.

A method for engaging a two piece locking-cap module with a connector, the method comprising:

• providing a locking module comprising a locking-cap and a set screw, the set screw being operably coupled with the locking-cap by a preloaded connection, the locking-cap including:
• a first connecting flange and a second connecting flange opposite the first connecting flange, the first and second connecting flanges extending from a side surface of the locking-cap and defining, at least partly, a top surface of the locking-cap;
• a first retaining rail and a second retaining rail opposite the first retaining rail, the first and second retaining rails extending from the side surface of the locking-cap and defining, at least partly, a bottom surface of the locking-cap;
• providing a connector, the connector including:
• an internal surface comprising a rod passageway and a connecting portion, the connecting portion disposed proximate an upper surface of the connector and configured to couple with the locking-cap such that the locking-cap is fixed relative to the connecting portion in an engaged position, the connecting portion including:
• a first connecting channel and a second connecting channel opposite the first connecting channel, the first connecting channel being configured to connect with the first connecting flange and the second connecting channel being configured to connect with the second connecting flange;
• a third connecting channel and a fourth connecting channel opposite the third connecting channel, the third connecting channel being configured to connect with the first retaining rail and the fourth connecting channel being configured to connect with the second retaining rail;
• providing a surgical tool having a proximal end including a drive end and a distal end including a rotatable drive feature, a plurality of arms and a plurality of mating rails;
• engaging the drive feature with a drive cavity of the set screw;
• rotating the locking-cap module, via the drive cavity of the set screw, into the engaged position thereby fixing the locking-cap relative to the connector such that an upper surface of the first connecting flange and an upper surface of the second connecting flange are generally flush with corresponding upper surfaces of the connector, respectively;
• rotating the set screw, after the locking-cap is fixed relative to the connector, with sufficient force to overcome the pre-loaded connection;
• and
• providing a counter-torque to the connector via engagement of (i) the plurality of arms of the surgical tool with a plurality of lateral sidewalls of the connector and (ii) the plurality of mating rails of the surgical tool with a plurality of mating channels of the connector.