Meniscal repair device

A meniscal tissue repair device includes an elongate body having a pointed distal tip. A plurality of lateral grooves is disposed along the body. Grooves disposed near the distal tip of the device are angled to open proximally and grooves disposed near the proximal end are angled to open distally. A torn meniscus can be repaired using the meniscal repair device by loading the meniscal repair device into an applicator, and inserting the barrel of the applicator through an incision in the knee at a location proximal and perpendicular to the tear in the meniscus. The applicator is actuated to drive the repair device distally into the meniscus across the tear. The distal travel of the repair device is limited by the distally-opening grooves of the repair device.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to surgical methods and apparatus for repair 
of meniscal tears. 
2. Description of the Related Art 
The menisci are crescent-shaped structures of fibrocartilaginous tissue 
located in the knee between the condyles of the tibia and the femur. The 
menisci, which are actually extensions of the tibia, serve to deepen the 
tibial plateau to better accommodate the opposing curvature of the 
articulating surface of the femoral condyle. 
A typical injury to the knee is a meniscal tear, which can occur, for 
example, when the meniscus is displaced and caught between the femoral and 
tibial condyles during a sudden change of movement of the knee involving a 
combined flexion-rotation or extension-rotation motion. Meniscal tears 
were originally treated by removing the meniscus in an operation called a 
meniscectomy. However, results showed that removing the meniscus, either 
entirely or even partially, resulted in degenerative arthritis and 
instability in the knee. 
As a result of the above-described complications, surgeons began treating 
torn meniscus tears with suturing techniques to retain as much of the 
meniscus as possible. However, suturing of a meniscal tear, like a 
meniscectomy, was originally an open technique, requiring a large incision 
and consequently longer periods of rehabilitation and recovery. Advances 
in instrumentation ultimately led to arthroscopic meniscal repair using 
long needles for passing suture through the tear. 
More recently, various tacks and screws have been developed for meniscal 
repair, which can be used arthroscopically and simplify the surgery by 
eliminating the need for suturing altogether. See, for example, U.S. Pat. 
Nos. 4,873,976; 4,884,572; 4,895,148; 4,924,865; 4,976,715; 5,059,206; 
5,129,906; 5,562,672; and 5,569,252. The known tacks and associated 
surgical methods have various disadvantages, such as the need for special 
preparation of the meniscus prior to insertion. 
SUMMARY OF THE INVENTION 
The present invention provides an improved meniscal repair device which, 
when used in conjunction with a specially-designed insertion gun, provides 
a simplified, quick and accurate method for repairing a torn meniscus. 
Briefly, the meniscal repair device of the present invention has a pointed 
distal tip, a proximal end, and a cylindrical body provided with a 
plurality of crescent-shaped grooves. The grooves on the front end of 
device face proximally and are disposed on opposite sides of the device in 
alternating fashion. The grooves on the proximal end of the device face 
distally. 
To insert the device into a torn meniscus, the device is first loaded into 
the elongated barrel of a spring loaded applicator, such that the back end 
of the device mates with the tip of the plunger of the applicator. The 
barrel of the applicator is then inserted through an incision in the knee 
and located arthroscopically at a location proximal and perpendicular to 
the tear in the meniscus. The trigger of the applicator is then actuated, 
releasing the plunger in the barrel, and driving the repair device 
distally into the meniscus across the tear. The distally facing grooves on 
the proximal end of the repair device limit forward motion of the device 
into the meniscus. Advantageously, the repair device of the present 
invention preferably is formed of a bioabsorbable material such as PLLA. 
The device and method of the present invention can be used not only to 
repair meniscal tears as described herein, but can also be used to repair 
any bodily tissue, such as cartilage, bone, skin and ligaments. 
Other features and advantages of the present invention will become apparent 
from the following description of the invention which refers to the 
accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring first to FIGS. 1-3, the present invention comprises a meniscal 
repair device 2 which has a pointed trocar tip 4 on the distal end, a 
rounded proximal end 6, and a cylindrical body 8. Along the body 8 is a 
plurality of lateral, crescent-shaped grooves 10, 12, disposed on opposite 
sides of the device in alternating fashion. 
The grooves are formed at an angle of about 30.degree. to the axis of the 
body 8. Grooves 10 on the distal end of device 2 open proximally. Grooves 
12 on the proximal end of the device open distally. The base of each 
groove typically is rounded. The surfaces of adjacent grooves 10, 12 on 
each side of the body 8 converge at an acute angle to form edges that 
anchor against the meniscal tissue. 
The grooves are spaced equally at either end of the body 8, with the 
pattern of grooves on one side of the device being offset by about half 
the distance between grooves on the other side of the device. 
The devices are provided in various lengths of 10 mm, 12 mm, and 14 mm. A 
device 2 of proper length is selected such that the inserted device does 
not protrude through the joint capsule. 
To insert device 2 into a torn meniscus, the device is first loaded into 
the elongated barrel of a spring loaded applicator 14, shown in FIGS. 4-6. 
Applicator 14 has a structure similar in certain respects to that 
disclosed in U.S. Pat. No. 5,546,957, the entire disclosure of which is 
incorporated herein by reference. Applicator 14 has a spring-loaded 
plunger 16 that slides within a barrel 18. After the plunger of applicator 
14 has been retracted by pulling rearwardly on knob 20, repair device 2 is 
loaded, proximal end first into applicator 14, such that proximal end 6 of 
device 2 mates with the tip of plunger 16 of applicator 14. 
After applicator 14 has been loaded with a repair device 2, applicator 14 
is grasped by a handle 22 and inserted through an incision in the knee, 
and the tip 23 of barrel 18 is located arthroscopically at a location 
proximal and perpendicular to the tear in the meniscus. After a safety on 
the applicator 14 has been switched off, trigger 26 of the applicator is 
actuated by the surgeon, releasing plunger 16 to move forcefully forwardly 
in barrel 18 under the force of spring 28, driving the repair device out 
of barrel 18 and distally into the meniscus across the tear. Protruding 
portions of the repair device can be cut off, through small separate 
incisions, if necessary. Advantageously, the repair device of the present 
invention is preferably formed of a bioabsorbable material such as PLLA. 
Referring to FIG. 7, three repair devices 30, 32, and 34 according to the 
present invention are shown having been inserted into tissue 36 to 
approximate a tear 38. The proximally-facing grooves of the repair devices 
limit the rearward motion. The distally-facing grooves limit the forward 
motion of the devices, and prevent over-insertion. 
The device and method of the present invention can be used not only to 
repair meniscal tears as described herein, but can also be used to repair 
any bodily tissue, such as cartilage, bone, skin and ligaments. 
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. Therefore, the 
present invention is to be limited not by the specific disclosure herein, 
but only by the appended claims.