Methods and apparatus for delivering and positioning sheet-like materials in surgery

1. A method of accurately positioning a sheet-like implant over a treatment site during arthroscopic surgery comprising the steps of: observing and measuring the treatment site to determine a preferred location for the sheet-like implant to be delivered; identifying a guidewire attachment point proximate the treatment site that is a known lateral and longitudinal distance from the preferred location for the sheet-like implant to be delivered; fixing a distal end of a guidewire at the guidewire attachment point, tracking an implant delivery system over a proximal portion of the guidewire to a position adjacent the guidewire attachment point, the implant delivery system having the sheet-like implant releasably coupled proximate a distal end thereof and a distal guidewire port disposed the known lateral and longitudinal distance relative to the sheet-like implant; and, deploying the positioned sheet-like implant, and wherein the implant delivery system further including a delivery shaft having a proximal end and a distal end defining a generally longitudinal direction; an implant retainer assembly proximate the distal end of the delivery shaft configured to releasably couple the sheet-like implant thereto for positioning the sheet-like implant at the treatment site, and wherein the implant retainer assembly comprises a center post disposed proximate the distal end of the delivery shaft and a mating surface spaced from the center post, wherein the mating surface cooperates with the center post to retain the sheet-like implant therebetween.

2. The method of claim 1 , further comprising the step of inserting a marker through a second location proximate the treatment site and rotating the implant delivery system to align the edge of the sheet-like implant adjacent the marker.

3. The method of claim 1 , the implant delivery system further including an implant spreader assembly proximate the distal end of the delivery shaft, the implant spreader assembly having a first arm and a second arm each having a proximal and a distal end with the proximal end of each arm connected proximate the distal end of the delivery shaft, the first arm and the second arm being moveable between a closed position and an open position wherein in the closed position the first arm and the second arm extend generally in the longitudinal direction and in moving to the open position the distal ends of the first and second arms move in generally opposite directions to spread a sheet-like implant positioned on the implant retainer assembly.

4. The method of claim 3 , further including a sheath disposed about the implant spreader assembly, the sheath and implant spreader assembly being slidable relative to each other in a direction generally parallel to a longitudinal axis of the delivery shaft such that the implant spreader assembly can be exposed distal of the sheath.

5. The method of claim 3 , wherein the sheet-like implant is in a first configuration when the first arm and the second arm are in the closed position and the sheet-like implant is in a second configuration when the first arm and the second arm are in the open position, and

wherein when the first arm and the second arm are in the closed position, the sheet-like implant is in a rolled configuration.

6. The method of claim 3 , wherein the sheet-like implant is in a first configuration when the first arm and the second arm are in the closed position and the sheet-like implant is in a second configuration when the first arm and the second arm are in the open position, and wherein when the first arm and the second arm are in the open position, the sheet-like implant extends tautly between the first arm and the second arm of the implant spreader.

7. The method of claim 3 , wherein the first arm and the second arm move transversely in different planes such that in the open position the sheet-like implant, extending between the first arm and the second arm and held by the implant retainer assembly, forms a generally curved surface to conform to a generally curved treatment site when placed thereon.

8. The method of claim 3 , wherein the first arm and the second arm move transversely in the same plane such that in the open position the sheet-like implant, extending between the first arm and the second arm and held by the implant retainer assembly, forms a generally flat surface to conform to a generally flat treatment site when placed thereon.

9. A method of positioning a sheet-like implant over a treatment site during arthroscopic surgery comprising the steps of: positioning an implant delivery system proximate a tendon of the shoulder at the treatment site, the implant delivery system comprising: a delivery shaft having a proximal end and a distal end and extending along a longitudinal axis, an implant retainer assembly proximate the distal end of the delivery shaft configured to releasably couple a sheet-like implant thereto, a sheet-like implant releasably coupled to the implant retainer assembly, an implant spreader assembly proximate the distal end of the delivery shaft, the implant spreader assembly having a first arm and a second arm each having a proximal and a distal end with the proximal end of each arm connected proximate the distal end of the delivery shaft, the first arm and the second arm being moveable between a closed position and an open position, wherein the distal ends of the first and second arms move away from the longitudinal axis when moving from the closed position to the open position to spread a sheet-like implant positioned on the implant retainer assembly, and a guidewire port proximate the distal end of the delivery shaft for receiving a guidewire therethrough, wherein the guidewire port location is positioned in known relation to a sheet-like implant when placed on the implant retainer assembly; transitioning the first arm and the second arm from the closed position to the open position to spread the sheet-like implant; and attaching the sheet-like implant to the tendon, and wherein the implant retainer assembly comprises a center post disposed proximate the distal end of the delivery shaft and a mating surface spaced from the center post, wherein the mating surface cooperates with the center post to retain the sheet-like implant therebetween.

10. The method of claim 9 , further comprising positioning a guidewire proximate the treatment site, and

fixing a distal end of the guidewire at the treatment site,

wherein positioning the implant delivery system proximate a tendon of the shoulder at the treatment site comprises tracking the implant delivery system over the guidewire to the treatment site.

11. The method of claim 9 , further including a sheath disposed about the implant spreader assembly, the sheath and implant spreader assembly being slidable relative to each other in a direction generally parallel to a longitudinal axis of the delivery shaft such that the implant spreader assembly can be exposed distal of the sheath.

12. The method of claim 9 , wherein the sheet-like implant is in a first configuration when the first arm and the second arm are in the closed position and the sheet-like implant is in a second configuration when the first arm and the second arm are in the open position, and

wherein when the first arm and the second arm are in the closed position, the sheet-like implant is in a rolled configuration.

13. The method of claim 9 , wherein the sheet-like implant is in a first configuration when the first arm and the second arm are in the closed position and the sheet-like implant is in a second configuration when the first arm and the second arm are in the open position, and wherein when the first arm and the second arm are in the open position, the sheet-like implant extends tautly between the first arm and the second arm of the implant spreader.

14. The method of claim 9 , wherein the first arm and the second arm move transversely in different planes such that in the open position the sheet-like implant, extending between the first arm and the second arm and held by the implant retainer assembly, forms a generally curved surface to conform to a generally curved treatment site when placed thereon.

15. The method of claim 9 , wherein the first arm and the second arm move transversely in the same plane such that in the open position the sheet-like implant, extending between the first arm and the second arm and held by the implant retainer assembly, forms a generally flat surface to conform to a generally flat treatment site when placed thereon.