Meniscal Repair with the Mitek (Fastner) Device

Abstract & Commentary

Synopsis: Laprell and colleagues report clinical success with the Mitek Fastner; however, they had several problems, including 1 case of cartilage injury, 5 failures, and 8 patients who had difficulty with duck walking at 1-year follow-up.

Source: Laprell H, et al. Arthroscopic all-inside meniscal repair using a new refixation device: A prospective study. Arthroscopy. 2002;18(4):387-393.

There are several meniscal repair devices that have been recently introduced. Although many of them are easier and quicker to insert than conventional inside-out sutures, sutures are still the standard with which they must be compared. One of these devices, the Mitek meniscal repair system, was evaluated in this European study. Thirty-seven patients were treated with this device, with a roughly equal distribution of men and women and medial and lateral meniscal repairs. Most of the repairs were within the vascular zone of the meniscus. Seventeen patients had a concomitant ACL tear that was reconstructed 6 to 8 weeks after the meniscal repair, giving the surgeon a chance to evaluate the repair. Depending on the size of the tear, 1-4 anchors were used. Patients were followed for at least 1 year postoperatively.

The most common intra-operative problem was loosening of the implant (1 in 6 cases). Subcutaneous migration was seen in one case. In the 17 cases re-evaluated at the time of ACL reconstruction, 5 had a residual cleft and 1 had a prominent device with superficial articular cartilage abrasion. At 1-year clinical follow-up, there were 5 reruptures (all in the red/white zone) and 3 additional cases of degenerative fraying of the inner rim of the meniscus. Eight additional patients had difficulty with duck walking. Eight of the 17 ACL reconstructions had a 1+ Lachman and 3 had a pivot shift. Despite these problems, Laprell et al conclude that their clinical results are promising.

Comment by Mark D. Miller, MD

Although many of these new meniscal repair devices are appealing because of their ease of insertion, I do not consider the results of this short-term report promising. Clearly the most stringent review of meniscal repair results is with second-look arthroscopy. Evaluation at 6-8 weeks showed residual clefts in 5 of 17 menisci and articular cartilage abrasion in 1. Clinical evaluation at 1 year, which is less stringent, demonstrated 5 reruptures and 8 patients with difficulty in duck walking. That means that 13 of 37 patients, which is more than one third of the group, had an unacceptable result with their meniscal repair. Although there are known problems associated with inside-out meniscal repair (nerve injury, technical difficulty, etc), numerous studies have shown better results with this technique.

The problem I have with this particular device is that there is very little flexibility in ensuring that adequate tension can be applied to the meniscal fixation. Some of the newer devices (such as the Smith & Nephew Fas-T-Fix and the Mitek Rapid Loc) do allow meniscal tensioning. Even these newer devices still have the risks of all all-inside devices, which include migration, late laxity, and articular cartilage injury. Additionally, all repairs in the red-white zone (where the 5 failures occurred in this study) should be treated with enhancement techniques (aggressive rasping, fibrin clot, etc) at the time of repair. I was surprised that Laprell et al still prefer to stage combined ACL and meniscal repairs. If these patients are followed closely postoperatively, combined ACL reconstruction with meniscal repair has been shown to be extremely successful. Additionally, some surgeons have proposed that bleeding from the ACL reconstruction may actually increase the success of meniscal repair. Perhaps a newer generation meniscal repair device will allow all of the features of traditional inside-out repair with the ease of insertion associated with all-inside repair, but we are not there yet!

Dr. Miller, Associate Professor, UVA Health System, Department of Orthopaedic Surgery, Charlottesville, VA, is Associate Editor of Sports Medicine Reports.