Distractor for lumbar insertion instrument

In combination, an instrument for inserting an intervertebral implant into an intervertebral space, the combination comprising:

• an implant comprising an upper part and a lower part having facing surfaces which face each other;
• and
• an implant insertion instrument comprising an upper arm for engaging the upper part, lower arms pivotally connectable to the upper arm and engaging the lower part, and a distractor between the upper and lower arms having seat portions which engage the arms and which are moved toward the upper and lower parts for separating the upper arm from the lower arm and hence for separating the upper part and the lower part;
• wherein the distractor creates a starting space between the upper part and the lower part and the distractor has a forward arm which protrudes forwardly of the seats and which is constructed and positioned to enter the starting space and to engage and move along at least one of the facing surfaces of the upper and lower parts for at least maintaining a separation of the upper and lower parts during use;
• wherein the distractor comprises a body with a wedge portion to slidably receive the upper arm to create the starting space, the wedge including a first one of the seats;
• wherein the forward arm comprises a plurality of parallel fork arms;
• and
• wherein the body further includes a resilient seat which engages and moves along the upper arm to maintain the body in position between the lower arms.

A method for inserting an intervertebral implant into an intervertebral space, comprising the steps of:

• assembling upper and lower parts of the intervertebral implant together on respective upper and lower arms of an elongated inserting instrument such that the upper and lower parts have facing surfaces which face each other;
• inserting the upper and lower parts into an intervertebral space such that an upper surface of the upper part and a lower surface of the lower part engage adjacent vertebrae;
• after the upper part and lower part are located in the intervertebral space, separating the upper and lower parts from each other with the elongated inserting instrument, wherein the separating step includes
• to initially separate the upper and lower parts apart, moving a distractor having contacting seats along upper and lower arms, which arms respectively engage the upper and lower parts, toward the upper and lower parts such that the distractor movement initially moves one of the upper and lower parts in the intervertebral space away from the other,
• engaging a portion of the distractor extending forwardly of the seats with one of the facing surfaces of the upper and lower parts as the upper and lower parts separate, and
• when the upper and lower parts are separated, inserting a third part of the implant into a space between the upper and lower parts created by the separating step while the elongated inserting instrument engages and supports the one of the facing surfaces;
• and
• wherein said engaging step includes the providing of a pair of fork arms as the portion of the inserting instrument engage the one of the facing surfaces;
• wherein said inserting step includes the moving of the third part with the distractor;
• wherein the distractor includes a body which moves along an upper arm and a pair of lower arms of the instrument, the body including a protrusion which engages the third part which is also mounted for movement along the lower arms;
• wherein said inserting step includes the moving of the third part with the protrusion;
• and
• wherein said separating step includes providing the body with a wedge portion including a first one of the seats which forces the upper arm away from the lower arm as the body moves, and providing the body with a resilient mounting to the upper arm to keep the body in position on the lower arms.

An insertion instrument for inserting an intervertebral implant of the type having an upper part and a lower part with facing surfaces which face each other, comprising:

• an upper arm and a lower arm disposed adjacent each other and pivotally supported relative to one another at respective held ends thereof, each upper and lower arm having a free end which is engageable with an associated one of the upper and lower parts of the implant;
• and
• a distractor which rests on the arms, moves along the arms, and separates the free ends of the upper and lower arms and hence the upper and lower parts from each other, the distractor including a body having a distal end and a forward arm protruding forwardly from said distal end,
• wherein the forward end engages one of the facing surfaces of the upper and lower parts as the upper and lower parts are forced apart, and
• wherein the body includes a resilient element which engages the upper arm to maintain the body resting on the lower arms as the body is advanced toward the implant.