Surgical instruments and method for use in surgically preparing a tibia for implantation of a prosthetic component

1. An orthopaedic surgical instrument assembly comprising:

a base trial adapted to be positioned on a proximal end of a patient's resected tibia, the base trial including a plate having (i) an opening defined therein, the opening including a first central opening and a first pair of elongated openings extending outwardly from the first central opening, and (ii) a pair of fixation pin holes defined in an anterior aspect, and

a guide tower including (i) a tower base adapted to be positioned on the base trial, the tower base having a passageway defined therein that is configured to be substantially aligned with the opening of the plate when the tower base is positioned on the base trial, and (ii) a pair of fixation pins extending downwardly from an anterior aspect of the tower base, each of the fixation pins being sized to be received in and extend outwardly from each of the fixation pin holes of the base trial when the tower base is positioned on the base trial,

wherein the passageway extends downwardly from a second central opening and a second pair of elongated openings extending outwardly from the second central opening that are defined in the tower base, and

wherein the second central opening and the second pair of elongated openings are configured to be substantially aligned with the first central opening and the first pair of elongated openings, respectively, when the tower base is positioned on the base trial.

2. The orthopaedic surgical instrument assembly of claim 1 , further comprising a second pair of fixation pins, wherein the plate of the base trial has a second pair of fixation pin holes defined in the anterior aspect and each of the second pair of fixation pins is sized to be received in and extend outwardly from each of the second pair of fixation pin holes.

3. The orthopaedic surgical instrument assembly of claim 1 , further comprising a handle removably coupled to the anterior aspect of the plate.

4. The orthopaedic surgical instrument assembly of claim 3 , wherein:

the plate has a notch defined therein and a pair of apertures defined on each side of the notch,

the handle includes a body, a pair of tabs extending from the body that are sized to be received in the pair of apertures, and a lever arm pivotally coupled to the body, the lever arm having a flange and being movable between (i) a first position in which the flange is received in the notch defined in the plate such that the handle is secured to the base trial, and (ii) a second position in which the flange is spaced apart from the notch such that the handle may be removed from the base trial.

5. The orthopaedic surgical instrument assembly of claim 4 , further comprising a biasing member that biases the lever arm in the first position.

6. The orthopaedic surgical instrument assembly of claim 1 , wherein the opening of the base trial and the passageway of the guide tower are sized to receive a surgical drill.

7. The orthopaedic surgical instrument assembly of claim 6 , further comprising a drill stop adapted to be positioned at an upper end of the guide tower.

8. The orthopaedic surgical instrument assembly of claim 7 , wherein the drill stop is formed from a first material and the guide tower is formed from a second material different from the first material.

9. The orthopaedic surgical instrument assembly of claim 1 , wherein the plate has a plurality of alignment etchings defined in the anterior aspect to align the plate with the proximal end of the patient's resected tibia.

10. An orthopaedic surgical instrument assembly comprising:

a base trial adapted to be positioned on a proximal end of a patient's resected tibia, the base trial including a plate having a first central opening and a first pair of elongated openings extending outwardly from the first central opening, defined therein, and

a guide tower including a tower base adapted to be positioned on the base trial, the tower base having (i) an anterior surface, (ii) an opening defined in a superior surface, the opening including a second central opening and a second pair of elongated openings extending outwardly from the second central opening, (iii) an inner surface extending inferiorly from the second central opening and the second pair of elongated opening to define a passageway that is configured to be substantially aligned with the first opening and the first pair of elongated openings of the plate when the tower base is positioned on the base trial, and (iv) a first aperture extending inwardly from the anterior surface to the inner surface such that the first aperture is in communication with the passageway.

11. The orthopaedic surgical instrument assembly of claim 10 , wherein the plate has a plurality of fixation pin holes defined in an anterior aspect thereof.

12. The orthopaedic surgical instrument assembly of claim 10 , wherein the tower base of the guide tower includes a pair of fixation pins extending downwardly from an anterior aspect of the tower base, each of the fixation pins being sized to be received in and extend outwardly from one of the fixation pin holes of the base trial when the tower base is positioned on the base trial.

13. The orthopaedic surgical instrument assembly of claim 10 , further comprising a surgical drill, wherein the opening of the base trial and the passageway of the guide tower are sized to receive the surgical drill.

14. The orthopaedic surgical instrument assembly of claim 13 , wherein the surgical drill has a plurality of horizontal lines defined thereon, and the guide tower extends a predetermined height corresponding to a first horizontal line of the plurality of horizontal lines and a first predetermined drilled-hole depth in the patient's tibia.

15. The orthopaedic surgical instrument assembly of claim 14 , further comprising a drill stop adapted to be positioned at an upper end of the guide tower, wherein the drill stop and the guide tower extend a second predetermined height corresponding to a second horizontal line of the plurality of horizontal lines and a second predetermined drilled-hole depth in the patient's tibia.

16. An orthopaedic surgical instrument assembly comprising:

a guide tower for a surgical drill, the guide tower comprising:

a tower base including (i) an anterior aspect having an anterior surface, (ii) an opening defined in a superior surface, the opening including a second central opening and a second pair of elongated openings extending outwardly from the second central opening, (iii) an inner surface extending inferiorly from the second central opening and the second pair of elongated opening to define a vertically-extending passageway, and

a pair of fixation pins extending downwardly from the anterior aspect of the tower base, each fixation pin being configured to be inserted into a proximal end of a patient's resected tibia.

17. The orthopaedic surgical instrument assembly of claim 16 , further comprising a drill stop adapted to be positioned at an upper end of the guide tower.

18. The orthopaedic surgical instrument assembly of claim 16 , wherein each fixation pin of the pair of fixation pins includes (i) a first section having a first cross-sectional diameter and (ii) a second section extending downwardly from the first section that has a second cross-sectional diameter, the second cross-sectional diameter being less than the first cross-sectional diameter.