An All-Inside Repair for Full Radial Posterior Lateral Meniscus Tears.

There is controversy about the treatment for unstable full radial posterior lateral meniscus tears, particularly that involving the posterior root. Some surgeons have advocated repairing these types of meniscus tears using various techniques, but their methods are somewhat technical. We developed the technique for an all-inside repair for full radial posterior lateral meniscus tears using the Meniscal Viper (Arthrex, Naples, FL). A doubled thread is passed through 1 edge of the radial tear by the Meniscal Viper and is kept in place without tying the knot. The Meniscal Viper is used again to set a new thread, repeating the same procedure to another edge of the tear. At this step, 2 doubled threads are passed through each stump of the tear, and both a loop end and 2 free ends of each thread are located outside of the joint. Then, 2 doubled threads pass the third thread into its own loop, pulling it out. Finally, the third thread becomes the mattress suture over the radial tear site and is fastened by sliding knot techniques. This procedure makes it easy to strictly, smoothly, and less invasively shorten the gap by drawing each stump of the meniscus in the direction of the circumference.

Anatomic Oblong Double Bundle Anterior Cruciate Ligament Reconstruction.

Double-bundle anterior cruciate ligament (ACL) reconstruction using hamstring tendon grafts is a standard procedure for ACL injury. However, its clinical effectiveness is not always satisfactory. One cause of this was problems with the graft-tunnel healing of the posterolateral bundle (PLB) on the femur. To solve this problem, we devised a new anatomic ACL reconstruction technique to improve the graft-tunnel healing of the femoral PLB by using a single-bundle with one bone tunnel on the femoral side and a double-bundle on the tibial side. We have performed 40 procedures with excellent results and no cases of intra- or postoperative complication. This procedure can help improve the graft-tunnel healing around the femoral bone tunnel aperture for the PLB.

Tendon-to-bone healing using autologous bone marrow-derived mesenchymal stem cells in ACL reconstruction without a tibial bone tunnel-A histological study-.

BACKGROUND: after anterior cruciate ligament (ACL) reconstruction, it is necessary to integrate free tendon graft biologically to the bone. In the present study, to verify whether a structure identical to the normal ligament-bone insertion could be regenerated at the tendon-bone interface without bone tunnel, we designed ACL reconstruction model without a tibial bone tunnel. Moreover, to enhance the integration process in this model, bone marrow-derived mesenchymal stem cells (bMSCs) were transplanted, and histological changes investigated. Our first hypothesis was that the grafted tendon would be anchored at part of the tendon-bone interface even if a bone tunnel was not created. Second hypothesis was that application of bMSCs at the tendon-bone interface would yield results histologically superior to those in controls. METHODS: bilateral ACL reconstruction using our originally designed method was performed. Autologous bMSCs with the carrier were transplanted between the bottom of the grafted tendon and the bone pit of the tibia in the experimental limb, whereas the control limb received the carrier only. At 4 and 8 weeks after the operation, histological comparison between bMSCs and the control group was carried out. RESULTS/CONCLUSIONS: even in our present ACL reconstruction model without a tibial bone tunnel, integration via chondroid tissue was seen at part of the tendon-bone interface. However, there were no appreciable differences between the groups. In ACL reconstruction, to enhance the tendon-bone integration without a bone tunnel would lead to save the graft length and prevent from bone tunnel complications (ex. Bone-tunnel enlargement after surgery).

Regeneration of ring-shaped lateral meniscus after partial resection of discoid meniscus with anterior cruciate ligament reconstruction.

INTRODUCTION: The ring-shaped lateral meniscus is very rare. Although it is essentially known as a congenital anomaly, a central tear in an incomplete discoid meniscus or an old bucket-handle tear in a meniscus may be easily mistaken for a ring-shaped meniscus. We experienced a ring-shaped lateral meniscus that regenerated after partial resection of a discoid meniscus together with anterior cruciate ligament (ACL) reconstruction. PRESENTATION OF CASE: A 37-year-old female patient still experienced unrelenting knee pain 6 months after ACL reconstruction and partial meniscectomy of a discoid lateral meniscus. A repeat arthroscopy was performed. The lateral tibial plateau was covered in the form of a ring by meniscus-like tissue. The meniscus-like tissue appeared to have regenerated inward toward the center from the stump after the partial meniscectomy and was connected from the anterior to posterior horn, forming an interhorn bridge. Partial meniscectomy was repeated. Histologically, the regenerated tissue was not meniscal, but comprised mature fibrocartilage; macroscopically; however, it was very similar to meniscal tissue. Two years after the initial operation, the patient had no complaints and experienced full return of function. DISCUSSION: The reason for such regeneration is unknown, but may have been attributed to the specific intra-articular environment that developed after the ACL reconstruction. CONCLUSION: This is the first report of regenerative development of a ring-shaped lateral meniscus. When a ring-shaped lateral meniscus is diagnosed, we must accurately determine whether it is a true congenital anomaly in consideration of the present case.

Inducement of semitendinosus tendon regeneration to the pes anserinus after its harvest for anterior cruciate ligament reconstruction-A new inducer grafting technique.

PURPOSE: To investigate the usefulness of the "inducer grafting" technique for regeneration of the semitendinosus (ST) tendon after its harvest for anterior cruciate ligament (ACL) reconstruction. METHODS: Twenty knees of 20 patients (mean age at the time of surgery, 23.1 years) underwent ACL reconstruction with a double bundle autograft using the ST tendon (7 patients) and the ST + the gracilis (G) tendons (13 patients)."Inducer grafting" techniqueAfter harvesting the ST tendon, a passing pin with a loop thread is inserted along with the tendon stripper. The passing pin is pulled out from the medial thigh and the loop thread retained. As an inducer graft, the ST tendon branch is used. After the ACL graft has been secured, the inducer graft is sutured to the pes anserinus and the proximal end passed through by pulling the thread out. Then the inducer graft is placed within the tendon canal. The mean follow-up period was 15 months. The presence and morphology of the regenerated ST tendon were examined by MRI. And the isometric hamstring strength was examined at 45°, 90° and 120° of knee flexion. RESULTS: One month after the operation in all the patients, MRI demonstrated a low-intensity structure at the anatomical location of the ST, at the level of the superior pole of the patella and the joint line, apparently representing the regenerated ST tendon. Four months after the operation, the distal portion of the regenerated ST tendon had reached the pes anserinus in all patients. Twelve months after the operation, the regenerated ST tendon was hypertrophic in 19 of the 20 patients (95%). The isometric knee flexion torque of the ACL-reconstructed limb was significantly lower at 90° and 120° compared with the contralateral limb. CONCLUSION: These results suggest that the "inducer grafting" technique is able to improve the regeneration rate of the harvested ST tendon and promote hypertrophy of the regenerated ST tendon, extending all the way to the pes anserinus. However, this technique couldn't improve the deficits in knee flexion torque after ACL reconstruction.