, which aligns with the ML slot 517. A plurality of intermediate hole openings 567, 568, 569 are defined along the arcuate body 562, aligned with various openings of the nail 500. More specifically, the hole opening 567 is aligned with the AP oblique opening 516, while the hole openings 568, 569 are each aligned with a respective oblique opening 515.

The openings 563, 565, 567, 568 and 569 are configured to support respective guide sheaths 579. The sheaths 579 are used to protect the soft tissue during the drilling process. The sheaths 579 accept drill sleeves and trocars of various sizes. In the present embodiment, the guide sheaths 579 do not include retention members, but instead, a friction retention assembly 580 is provided in each opening 563, 565, 567, 568, 569. An illustrative friction retention assembly 580 will be described with reference to FIGS. 9-11.

Each friction retention assembly 580 includes a friction pad 582, 582′ positioned within a blind bore 581 adjacent to and opening into a respective opening 563, 565, 567, 568, 569. Each friction pad 582, 582′ extends from a contact surface 583, 583′ to a rear surface 584. The contact surface 583 for the friction pads 582 associated with the openings 563, 567, 568, 569 has an arcuate configuration which complements the outside surface configuration of the sheath 579. The contact surface 583′ for the friction pads 582′ associated with the openings 565 has two arcuate portions with each complementing the outside surface configuration of the sheath 579 to accommodate the different positions with which the sheath 579 may be aligned with the ML slot 517. Additionally, each contact surface 583, 583′ is angled such that it is substantially parallel to the central axis of the respective opening 563, 565 567, 568, 569 (see FIG. 9).

A spring 586 or other biasing member is positioned between the rear surface 584 of the friction pad 582, 582′ and the blind end of the bore 581 to bias the friction pad 582, 582′ toward the respective opening 563, 565, 567, 568, 569 such that the contact surface 583, 583′ extends into the opening 563, 565, 567, 568, 569 such that it may contact and retain the sheath 579. The rear surface 584 of the friction pad 582, 582′ may include a notch 585 or the like to retain alignment of the spring 586. To retain the friction pad 582, 582′, and thereby the spring 586, within the bore 581, a retaining pin 589 extends through the body 562 and through a slot 587 defined through the friction pad 582, 582′. The slot 587 has a length larger than the diameter of the retaining pin 589 such that the friction pad 582, 582′ is axially moveable within the bore 581, with the slot 587 defining the range of motion of the friction pad 582, 582′. The friction pads 582, 582′ are generally biased toward the contacting position, however, application of a sufficient force on the sheath 579 will cause the friction pad 582, 582′ to move against the force of the spring 586 into the bore 581 whereby the sheath 579 may be advanced or withdrawn.

The aiming guide 560 also includes a connection assembly 570 configured to mate with the connection assembly 550 on the insertion handle 540. The connection assembly 570 includes a body 572 configured to be received within the recessed area 552 of the handle connection assembly 550 with a distal surface 571 contacting the distal stop 551 and a proximal surface 573 contacting the proximal stop surface 553. A pair of connection posts 574 extend from the body 572 and are configured to be received in the non-threaded bores 555 of the connection assembly 550. A rotatable screw 576 with a head 578 extends through the body 572 and is configured to threadably engage the threaded bore 556 to secure the aiming guide 560 with the insertion handle 540. The connector assembly body 575 is a rigid structure and may be made from, for example, metal.

Accordingly, the system 530 provides an insertion handle 547 with reliable and convenient connection assembly for attaching the aiming guide 560. A threaded connection with an accessible head allows tool free connection and disconnection of the aiming guide 560. The insertion handle 547 also contain an external compression bolt 544 used to apply pressure the locking screw in the dynamic position to compress a fracture gap. The aiming guide 560 utilizes friction retention assemblies 580 that lock the soft tissue sheaths 579 in place. The friction retention assembly 580 allows insertion of the soft tissue sheath 579 but prevents it from backing out. This feature helps to maintain the position of the soft tissue sheaths 579 for accurate screw length measurements and facilitates drilling and screw insertion. The aiming guide 560 is designed with extended sheath guides 579 for improved aiming accuracy.

The supra-patellar approach uses a tibia entry point above the knee. A system 530′ for use with the supra-patellar approach will be described with reference to FIGS. 12-30. The system 530′ is substantially as in the previous embodiment but further includes a cannula assembly 590. As illustrated in FIG. 12, at the time of insertion of the nail 500, the nail 500 and the connection portion 545 of the insertion tool 540 are inserted through the cannula assembly 590. The cannula assembly 590 protects the articular surface of the knee during the nail insertion process. As will be described below, the cannula assembly 590 also protects the articular surface of the knee during reaming. The reaming is performed through a drill guide 610 in the cannula 592 of the cannula assembly 590. Thereafter, the drill guide 610 is removed and nail 500 insertion is performed through the cannula 592 into the entry incision.

Referring to FIG. 13, an illustrative cannula assembly 590 will be described. The cannula assembly 590 includes a flexible cannula 592 and a rigid handle 596. The cannula 592 has a through passage 594 which is aligned with an opening 599 in the handle 596 to define a continuous passage. The soft, flexible cannula 592 is anatomically shaped to fit between the femoral condyles and minimize damage to the articular surface. In one embodiment, the flexible cannula 592 material is over-molded onto the rigid plastic handle 596. A pair of tibia guide slots 595 extend through the handle 596 and along the sides of the cannula 592. Transverse femur guide holes 597 extend through the handle