Injury to the knee involving a tear in the meniscus is a common occurrence, often in the context of athletic events, and is prevalent in the younger population. The meniscus is recognized as being vital to the biomechanical stability and protection of the knee joint. Damage to the meniscus can greatly increase the likelihood of the articular surfaces of the knee joint developing conditions such as osteoarthritis. A common remedy in the past for tears in the meniscus involved removal of the meniscus. However, this is not a favored option as it has been shown that degenerative changes in the knee are directly proportional to the amount of meniscus removed. Thus, in many instances it is desirable to repair the torn meniscus with the objective being to prevent instability of the knee joint and to prevent onset of conditions such as osteoarthritis.
Current methods for repairing tears in the meniscus are technically very challenging for the surgeon. One widely used technique requires that a long needle with a suture be passed through the torn meniscus and the knee joint. The needle carrying the suture is passed through the meniscus and the knee in its entirety several times until the meniscal tear is closed. As this procedure is typically performed arthroscopically, the amount of space available within the knee for manipulating the long needle through the meniscus is extremely limited. The procedure often requires more than one pair of hands, with one pair inserting the needle into the knee while another pair uses graspers, operating in the limited inflated space in the interior of the knee, to shuttle the needle through the meniscus and out the other side of the knee.
Using such current methods, it is difficult for a surgeon to advance the entire needle without the use of a number of other instruments, which complicates the procedure and may unnecessarily damage tissue in the operating area. Furthermore, it is difficult to manipulate and advance a long thin needle for penetrating the meniscus and the surrounding tissue in the knee without an aptly designed driving mechanism. The needle typically needs to penetrate the skin on the anterior side of the knee, pass through the synovial sac and the torn meniscus, and exit on the posterior side of the knee. Having a needle driver would reduce the complexity of manipulating and passing the needle through the knee.
An alternative meniscal repair technique involves the implantation of resorbable anchors into the meniscus in order to fasten torn or displaced tissue. Systems for delivering meniscal anchors are commercially available from Bionix, Inc., Malvern, Penn., under the trade name Meniscus Arrow.TM.. The arrows are formed from a resorbable material (polylactic acid) and are elongate elements having barbs spaced-apart along their lengths. The anchors are delivered through a canula by insertion using a blunt obturator.
Both suturing and the use of anchors will continue to find use in performing meniscal repairs. Often times, however, it is not known at the outset of a repair procedure whether the use of sutures or anchors would be most beneficial. Thus, it may become necessary to use two entirely different repair systems during the course of a single arthroscopic meniscal repair procedure. Such duplication is both costly and inconvenient. In some cases, the treating physician may decide to use only a single system even though use of both types of repairs would be most beneficial to the patient.
For these reasons, it would be desirable to provide improved devices and methods for repairing tears in the soft tissue of the body. It would be particularly desirable to have devices and methods for incrementally advancing a needle into the body for suturing meniscal tears in the knee. It would be further desirable to provide devices and methods which are able to perform both suturing and the delivery of meniscal anchors with only minor modifications.