Dovetail method of allograft transplantation

A technique for forming a dovetail shaped groove in bone necessary in allograft transplantation such as the meniscus or the Achilles tendon. The technique uses a single drill guide that is designed to create a dovetail shape in bone. The drill guide is provided with a first opening for receiving one drill sleeve placed in a fixed location, and a second opening having an oblong shape for receiving a second drill sleeve having an offset cannulation. The combination of the two drill sleeves allows the surgeon to place two guide pins and ream over each guide pin resulting in a dovetail shape in the bone.

FIELD OF THE INVENTION

The present invention relates to the field of surgery reconstruction, particularly, a method for performing an allograft transplant using a dovetail technique.

BACKGROUND OF THE INVENTION

A known method for inserting a meniscal allograft is the dovetail meniscal allograft technique disclosed in U.S. Pat. No. 7,124,762, herein incorporated by reference. According to this technique, a bone block with a trapezoidal shape is delivered to a recipient dovetail slot in the tibia, the formation of which requires the use of drill bits, dilators, and rasps. This method requires several steps and multiple instruments to perform (i.e., multiple cutting guides and/or free hand instruments to create the dovetail shape of the groove in the tibia).

A dovetail meniscal technique that is quicker and uses fewer instruments is needed. Also needed is a single cutting guide to create an outline for the dovetail shape that requires little modification after reaming.

SUMMARY OF THE INVENTION

The present invention provides methods and instruments for forming a dovetail shaped groove in bone necessary in allograft transplantation such as the meniscus or the Achilles tendon. The technique uses fewer instruments and takes less time. The technique uses a single drill guide that is designed to create a dovetail shape in bone. The drill guide is provided with a first opening for receiving one drill sleeve placed in a fixed location, and a second opening having an oblong shape for receiving a second drill sleeve having an offset cannulation. The combination of the two drill sleeves allows the surgeon to place two guide pins and ream over each guide pin resulting in a dovetail shape in the bone.

In one embodiment, the drill guide includes a body with two holes extending through the body. The drill guide includes a first cannulated sleeve within the first hole, and a cannulated sleeve within the second hole. The cannulation of the first sleeve is situated with regard to the cannulation of the second sleeve so that a plane formed through the centers of the two holes through the drill guide is non-parallel with a plane formed through the centers of the cannulations of the first and second sleeves.

In another embodiment the drill guide includes a body having four sides. The body also has a first hole extending through the body and a second hole extending through the body. The drill guide also includes a first cannulated sleeve within the first hole, and a second cannulated sleeve within the second hole. The cannulation of the first sleeve is situated with regard to the cannulation of the second sleeve so that the centers of the two cannulations are offset in two dimensions and the center of the cannulation of the first sleeve is proximal to the first and second sides of the body and the center of the cannulation of the second sleeve is distal to the first and second sides of the body.

A method of surgery is also disclosed. In one embodiment, the method includes providing a body, the body having first and second holes that extend through the body. Additionally, a first cannulated sleeve is placed within the first hole, and a second cannulated sleeve is placed within the second hole. The cannulation of the first sleeve is situated with regard to the cannulation of the second sleeve so that a plane that intersects the centers of the two holes is non-parallel with a plane that intersects the centers of the cannulations of the two sleeves.

The method also includes placing a first guide pin within the cannulation of the first sleeve and placing a second guide pin within the cannulation of the second sleeve and inserting the first and second guide pins into a bone. Further, the first and second guide pins are used to guide a drill to create first and second channels in the bone so that an allograft implant may be placed within the first and second channels.

These and other features and advantages will be more apparent from the following detailed description that is provided in connection with the accompanying drawing and illustrated exemplary embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a technique for forming a longitudinal groove in bone, the groove having a dovetail or trapezoidal cross-section for implantation of an allograft such as a meniscal or Achilles allograft.

The present invention also provides instruments for forming the dovetail shaped groove in bone necessary in allograft transplantation. A single drill guide is designed to create a dovetail shape in bone. The single drill guide is a double socket drill guide used to precisely place two guide pins that the surgeon can then ream over to create a dovetail shape in the tibia. The drill guide is provided with a first opening for receiving a first drill sleeve placed in a fixed location, and a second opening having an oblong shape for receiving a second drill sleeve having an offset cannulation. The first drill sleeve is round and placed at a constant location. The second drill sleeve has an oblong shape with an offset from the center cannulation, the oblong drill sleeve creating the left and right offset based on which way is inserted into the guide.

Referring now to the drawings, where like elements are designated by like reference numerals,FIGS. 1-9illustrate an exemplary technique of forming a longitudinal dovetail groove that accommodates a dovetail meniscal allograft implant.

A dovetail meniscus implant can be machined from allograft cortical bone using known techniques and is preferably a single piece of harvested material with the meniscus on a bone block. An exemplary dovetail meniscus implant300has a meniscus310hanging freely from bone block315as shown inFIG. 8. The dovetail configuration A is a cross-sectional trapezoidal shape with four edges A1(height), A2(base), A3and A4(small base), edges A1and A2forming a 90° angle and edges A2and A3forming an acute dovetail angle α, as shown inFIG. 8. Alternatively, the implant can be formed of a synthetic material, preferably a synthetic cortical bone material. A preferred synthetic material is tricalcium phosphate (TCP) and/or hyroxyapatite (HA), or a biodegradable polymer, preferably a polyactide, such as PLLA or a combination of some or all of the aforementioned materials.

Drill guide100of the present invention is illustrated inFIGS. 1-4. As shown in the drawings, drill guide100includes a marking hook50and handle60. The drill guide100has a first opening10having a circular shape and a second opening20having an oblong or rectangular shape (FIG. 1). As shown inFIG. 2; first opening10is designed to receive drill sleeve15. Drill sleeve15is cannulated to receive a guide pin17(FIG. 4). Second opening20is designed to receive a second drill sleeve25also cannulated to receive a guide pin27(FIG. 4). Second drill sleeve25may have an oblong or rectangular cross-section to allow for the cannulation to be offset from center as shown inFIG. 2. The oblong cross-section of the second drill sleeve25allows the second guide pin27to be placed either to the left or right of the center of guide pin17by simply flipping the drill sleeve25in opening20.

An exemplary technique for forming a longitudinal groove having a dovetail cross-section in the tibia is described below. Drill guide100is placed proximate to the tibia200using the marking hook50to stabilize the drill guide in the desired position.FIG. 1illustrates drill guide100positioned for drilling using marking hook50. Drill sleeve15is placed through opening10. Drill sleeve25is placed through opening20. The drill sleeves do not have to be placed in any order, either one may be inserted first. Guide pins17,27are inserted through the drill sleeves.

After placement of the guide pins, the entire drill guide instrument is removed leaving the guide pins17,27in the bone as shown inFIG. 4. A reamer (not shown) is then used over guide pin17to create a first channel70in the bone. A second reamer (not shown) having a larger diameter than the first reamer is then used over guide pin27to create a second channel80overlapping or intersecting with the first channel70, as shown inFIG. 5. The resulting groove is easier to then form into the desired dovetail cross-sectional groove to accommodate the dovetail meniscal allograft. A rasp or broach may be used to finalize the shape by removing the remaining bone shown in the outlined area inFIG. 6. The final dovetail shaped groove90is shown inFIG. 7.

Finally, the dovetail meniscal allograft implant300(FIG. 8) is passed into the recipient dovetail tibial groove90, as shown inFIG. 9. Any remaining bone debris in the dovetail groove is cleared. As the dovetail meniscal allograft implant is delivered to the tibial groove, the graft passing suture attached to the meniscal allograft implant is lead out the posterior lateral capsule via a standard inside out meniscal suturing technique. A meniscal allograft tamp may be employed to position the meniscal allograft implant into the dovetail tibial groove.

Another embodiment is illustrated inFIGS. 10 and 11. In this embodiment, drill guide205includes a body230, a marking hook250, and a handle260. The drill guide205has a first opening210having a circular shape and a second opening220having a circular shape. As shown inFIG. 11, first opening210is designed to receive drill sleeve215. Drill sleeve215is cannulated to receive a guide pin. Second opening220is designed to receive a second drill sleeve225and is also cannulated to receive a guide pin. Second drill sleeve225is circular but the cannulated shaft is offset from center as shown inFIG. 11. The offset cannulated shaft of the second drill sleeve225allows the second guide pin to be placed either to the left or right of the center of guide pin by simply flipping the drill sleeve225in opening220. Further, the cannulated shafts of the first and second drill sleeves215,225have center points.

Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art.