Leeds-Keio Artificial Ligament Research Articles

Efficacy and safety of anal encirclement combining the Leeds-Keio artificial ligament with injection sclerotherapy using aluminum potassium sulfate and tannic acid in the management of rectal prolapse: a single-center observational study.

Perineal procedures are an important surgical option for frail and high-risk patients with rectal prolapse. This study aimed to evaluate the efficacy and safety of combined therapy using injection sclerotherapy, with aluminum potassium sulfate and tannic acid (ALTA), and the Thiersch procedure, using the Leeds-Keio ligament (ALTA-Thiersch). This study included 106 consecutive patients (mean age, 81.2 years) who underwent ALTA-Thiersch for rectal prolapse. The procedure was performed under caudal epidural anesthesia. ALTA was injected into the submucosa from the tip of the prolapsed rectum down to the dentate line, circumferentially, at 20 to 40 locations. The ligament tape was placed outside the external sphincter muscle and at an approximate depth of 2 cm into the middle anal canal. Of 106 patients, rectal prolapse was cured shortly after surgery in 105 patients. An additional tape was inserted in 1 patient who had persistent prolapse. Postoperative complications were observed in 27 patients (25.5%). Fecal impaction occurred in 12 patients; however, since it was temporary, no tape removal was required. Of the 12 cases in which the tape was infected or exposed, 11 required tape removal. There were 18 cases of recurrence at a mean follow-up of 22.1 months. Cumulative recurrence rates at 3 and 5 years were 21.3% and 38.6%, respectively. ALTA-Thiersch is a simple and safe procedure for rectal prolapse, having reasonable outcomes. The use of the Leeds-Keio ligament for anal encircling can help compensate for the disadvantages of the Thiersch operation.

Anterior cruciate ligament reconstruction: a look at prosthetics - past, present and possible future

Biological tissue autograft reconstruction using the patellar tendon or quadrupled semitendinosus/gracilis tendons has become the most popular procedure in surgical treatment of a ruptured ACL. This article provides a review of the history of the use of prosthetics with respect to ACL reconstruction grafts including Carbon Fibre, Gore-Tex and Dacron prosthetics as well as the Leeds-Keio Artificial Ligament and the Kennedy Ligament Augmentation Device (LAD). Emphasis is placed on the Ligament Advanced Reinforcement System (LARS) as preliminary investigations of its use have been encouraging. Significant progress has been made recently with respect to the understanding of ACL anatomy, composition, biomechanics, and healing processes, leading to innovative techniques using approaches based in tissue engineering principles and computer - assisted surgery. While research into improved ACL treatment options continues, the synthesis of recent advancements provides a new optimism towards the regeneration of an ACL mirroring its original stability, function, and longevity.

Soft tissue reinforcement with a Leeds-Keio artificial ligament in revision surgery for dislocated total hip arthroplasty.

Since dislocation after total hip arthroplasty (THA) greatly diminishes patient's quality of life, the THA frequently needs revision. However, it is common for the dislocation not to heal even after reconstruction, but rather to become intractable. The 17 patients with dislocated THA, mean age of 71 years (range 51-87 years), who underwent a revision THA together with soft tissue reinforcement with a Leeds-Keio (LK) ligament were enrolled. The purposes of reinforcement with LK ligament were to restrict the internal rotation of the hip joint, and to encourage the formation of fibrous tissue in the posterior acetabular wall to stabilise the femoral head. We determined the success rate of surgical treatment for dislocation, the Harris Hip Score (HHS), a factor of recurrent dislocation. There was no recurrent dislocation in 82% of the cases (14 joints) during the mean postoperative follow-up period of 63.5 months (15-96 months). The HHS was 82 ± 18 points preoperatively and 82 ± 14 points postoperatively. Recurrent dislocation after this surgical procedure occurred in 2 hips with breakage of the LK ligaments, and intracapsular dislocation in 1 hip with loosening of the LK ligament. Although the risk of recurrent dislocation still exists with this procedure, when performed to provide reinforcement with an LK ligament for dislocated THA it may be useful in intractable cases with soft tissue defects around the hip joint.

Combined aluminum potassium sulfate and tannic acid sclerosing therapy and anal encirclement using an elastic artificial ligament for rectal prolapse.

Aluminum potassium sulfate and tannic acid is a sclerosant used for sclerosing therapy in the treatment of hemorrhoids, and a Leeds-Keio artificial ligament is a new anal-encircling material for the management of rectal prolapse. The aim of this study was to evaluate clinical data and recurrence rates in patients with rectal prolapse undergoing combined aluminum potassium sulfate and tannic acid injection and anal encirclement using the Leeds-Keio artificial ligament. This was a retrospective review of patients who underwent this procedure. This study was conducted at a community-based hospital within a specialized colorectal unit. A total of 23 patients (20 women; median age, 83 years) with full-thickness rectal prolapse underwent treatment between 2005 and 2010. The main outcome measures were morbidity and recurrence rate. The median duration of surgery was 36 minutes. Mean total injection dose of aluminum potassium sulfate and tannic acid was 30 mL. There were no postoperative deaths. Wound infection occurred in 2 patients (9%), and new or worsening symptoms of constipation after surgery occurred in 6 patients (26%). There were 3 recurrences at a median follow-up of 36 months (range, 7-86 months). Recurrence rate at 5 years was 14% (95% CI, 5%-35%). The limitations of this study include its retrospective nature, the potential for selection bias, and lack of a control group. This procedure is quick and easy to perform, with no formidable morbidity, and the recurrence rate is reasonably low. Therefore, it seems to be a reasonable alternative for rectal prolapse in frail, elderly, and high-risk patients.

腱板大断裂に対しLeeds-Keio人工靱帯と大腿筋膜による複合組織移植を行った症例の術後成績と術後Motion MRI

腱板大断裂に対しLeeds-Keio人工靱帯と大腿筋膜による複合組織移植を行った症例の術後成績と術後Motion MRI

A New Method of Limb Salvage and Functional Upper Limb Reconstruction

Amputation is frequently used to treat malignant tumors invading into the shoulder joint. When the vessels and major nerves of the upper arm are preserved, however, the limb may be salvaged with a combined osseous, myocutaneous flap. We reconstructed large defects, which included the shoulder joint, using a vascularized rib-latissmus dorsi combined flap. Ribs were connected via the ninth or tenth posterior intercostal artery. Several slits were cut in the ribs, and the rib was glass stick fractured to straighten it. The thoracodorsal nerve was preserved and the latissmus dorsi muscle was transferred to the defect previously occupied by the biceps humerus. The ribs were connected to the residual clavicle via a Leeds-Keio artificial ligament. The flaps completely engrafted. The patient was able to flex her elbow relatively early postoperatively. The function of the hand was preserved intact. In conclusion, the combined vascularized rib-latissmus dorsi flap is useful for patients who require functional or bony reconstruction of large defects involving the shoulder joint.

Revision of Reconstructed ACL with the Leeds-Keio Artificial Ligament

Revision of Reconstructed ACL with the Leeds-Keio Artificial Ligament

RETRACTED ARTICLE: ACL prosthesis: any promise for the future?

Biological tissue autograft reconstruction using the patellar tendon or quadrupled semitendinosus/gracilis tendons has become the most popular procedure in surgical treatment of a ruptured anterior cruciate ligament (ACL). This article provides a review of the history of the use of prosthetics with respect to ACL reconstruction grafts including Carbon Fibre, Gore-Tex and Dacron prosthetics, as well as the Leeds-Keio Artificial Ligament and the Kennedy Ligament Augmentation Device (LAD). Emphasis is placed on the ligament advanced reinforcement system (LARS) as preliminary investigations of its use have been encouraging. Significant progress has been made recently with respect to the understanding of ACL anatomy, composition, biomechanics, and healing processes, leading to innovative techniques using approaches based in tissue engineering principles. Most of grafts that have been developed to date have failed due to unsatisfactory long-term physiological and functional performance. Most permanent ACL prostheses are prone to creep, fatigue, and mechanical failure within several years after implantation. In view of these factors, prosthetics are not widely used today in ACL reconstruction, and autogenous tissue grafts remain the gold standard used by the majority of surgeons. Perhaps development of resorbable, tissue inducing and cell-seeded biomaterials will improve the long-term biomechanical performance of the reconstructed ACL. Tissue ingrowth scaffolds and ligament augmentation devices require further refinement to provide effective mechanical support while avoiding stress shielding of the host tissue. While research into improved ACL treatment options continues, the synthesis of recent advancements provides some new optimism towards the regeneration of an ACL mirroring its original stability, function, and longevity.

Histologic Examination of Leeds-Keio Artificial Ligament Implanted on the Surface of a Tumor Endoprosthesis

The Leeds-Keio (L-K) artificial ligament is made of polyester fibers with an open-weave mesh structure. It has been used clinically for knee ligament reconstruction as a scaffold, allowing tissue ingrowth and new ligament formation. We have used the L-K ligament in bone tumor surgery for reattaching remaining muscles to the target zone of a tumor endoprosthesis. We histologically examined the L-K ligament obtained from 2 patients during revision surgery 39 months after the primary surgery. There were dense fibrous tissues between muscles and the L-K ligament. Collagen fibers proliferated in the space between the polyester fibers, and a slight inflammatory reaction was apparent. We concluded that the L-K ligament had a high potential for inducing biological tissue regeneration even on the metal surface.

Augmented subscapularis muscle transposition for rotator cuff repair during shoulder arthroplasty in patients with rheumatoid arthritis

The effectiveness of rotator cuff repair by augmented subscapularis transposition via the Leeds-Keio artificial ligament was evaluated in patients with rheumatoid arthritis undergoing total shoulder arthroplasty. The minimum follow-up period was 2 years. Final clinical scores (Hospital for Special Surgery scoring system) and the incidence of radiolucency and upward migration of shoulder components in 20 shoulders with rotator cuff repair by augmented subscapularis transposition were superior to those of 19 shoulders with cuff repair by subscapularis transposition alone and similar to those of 22 shoulders with intact rotator cuffs. In shoulders with augmented subscapularis transposition and intact cuffs, clinical scores continued to improve even after the first postoperative year. Our augmented subscapularis transposition did not increase postoperative complications. We conclude that cuff repair by augmented subscapularis transposition is an acceptable alternative for repairing a supraspinatus or supraspinatus and infraspinatus rotator cuff defect in rheumatoid arthritis patients undergoing total shoulder arthroplasty.

人工靭帯を用いた膝伸展機構再建術後に機能不全をきたした１例

We report a case of dysfunction following reconstruction of the knee extensor mechanism using artificial ligament. Three years ago, a 49-year-old man sustained an injury of the patella fracture of the left knee in a traumatic event. Since then, he had not been able to walk without crutches or extend his left knee completely. Plain radiograph showed two divided bony fragments of the patella and that the periarticular bone had changed atrophically. The distance between the two fragments was approximately 7cm. The knee extensor apparatus recontruction was performed using the Leeds-Keio artificial ligament, which was fixed to the tibia with double staples. The rehabilitation program was controlled strictly. Eighteen weeks after the operation, no extension lag was found and he could walk by himself. At 28 weeks after the operation, however, he had not been able to extend the operated knee on his own and the extension lag increased to 20°suddenly. On examination at 47 weeks after operation, the MRI showed loosening of the artificial ligament resulting from weak fixation due to the tibial atrophy. Although the knee extensor apparatus recontruction using artificial ligament is a good method, results for this case were poor. We concluded that it is necessary to reinforce the fixation of the artificial ligament in such bone atrophy cases by the addition of another augmentation.

Anterior Cruciate Reconstruction with Bioactive Leeds-Keio Ligament (LKII): Preliminary Report

The scaffold type Leeds-Keio artificial ligament (LK) for ligament reconstruction of the knee provides sufficient strength to require minimal sacrifice of autogenous tissue. This implant works not only as prosthesis but also as scaffold onto which natural tissue grows from the synovium. LK has been in clinical use for anterior cruciate ligament (ACL) reconstruction since 1982, although the operative procedure has been modified and has undergone significant development since that time. Recently, we developed radio frequency-generated glow discharge (RFGGD)-treated LK ligament (LKII, previously indicated as Bio-LK) to improve tissue induction and reported that cell proliferation and cell attachment to artificial fibers increased considerably with this hydrophilic treatment. In this study, we report the findings of reconstructed ACL using LKII, which has been in clinical use since 2003. At reconstruction, LKII was covered with the remnant of the original ACL as much as possible in order to preserve the nerve ending system. Thirteen cases with over 12 months' postoperative history were reviewed. Knee stability was regained after reconstruction without any complications such as joint effusion and chronic synovitis. In one case, postoperative arthroscopy showed that the reconstructed ACL was completely covered with newly formed tissue at 8 weeks postoperatively. Biopsy revealed abundant fibroblasts, collagenous fibers, and vessels around the artificial fibers without marked inflammatory findings. Transmission electron microscope study showed abundant thin collagen fibers, which demonstrated regular orientation to some extent. Fibroblasts were observed with extensive amount of rough endoplasmic reticulum. According to these results, we consider LKII to be superior to LK in tissue induction and maturation.

膝蓋けん断裂に人工靭帯を使用した治療経験

Patellar tendon rupture rarely occurs in adults without systemic diseases. We report two cases of fresh patellar tendon rupture treated with augmentation using the Leeds-Keio artificial ligament. The remnants of the ruptured tendon were preserved. The artificial ligament was passed transversely through the distal end of the quadriceps tendon along the proximal margin of the patella and it crossed itself in front of the patella in a cross shape. Both ends of the implant were passed through a transverse tunnel drilled through the tibial tuberosity. CPM exercise was begun on the second day after surgery. Active knee extension was permitted at three weeks postoperatively. The advantages of this method are there is no need for immobilization and that rehabilitation is much quicker.

Effect of implant lengthening and mode of fixation on knee laxity after ACL reconstruction with an artificial ligament: a cadaveric study

An “apparent” lengthening of the ligament implant, which causes an increase in knee laxity after the reconstruction of the anterior cruciate ligament (ACL) may be due to either slippage of the implant from under the fixation devices, or tunnel migration (due to bone resorption). These two mechanisms are related to the initial ligament placement, implant tensioning, and fixation modes. This cadaveric study simulates, in a controlled experimental situation, the postoperative lengthening of artificial ACL implants, and seeks to quantify the consequent increase in joint laxity. Eight cadaveric right knees, in which the Leeds-Keio artificial ligament was implanted, were tested in a specially constructed apparatus, which allowed the knee joint six degrees of freedom. In each of the tested joints the laxity was measured under several test conditions for two final fixation modes of the implant. The difference between the fixation modes was the application (as in mode B) or not (as in mode A), of a posteriorly directed force of 50N on the tibia, at the moment of final fixation of the ligament. In both cases a tensile load of 50N was maintained along the implant. All measurements were taken at flexion angles of 20° and 90° and with controlled implant lengthening of up to 3mm in 0.5-mm increments. After implantation, adopting fixation mode B resulted in the knee exhibiting an anterior laxity considerably less than the original physiological laxity, compared with that measured after using fixation mode A. Thus at 20° of knee flexion, under an anterior load of 100N applied on the tibia, adopting fixation mode B, the joint laxity was 2.8mm smaller than the natural laxity, whereas, for fixation mode A, it was 1.4mm larger. At 90° of knee flexion, the situation was similar, but with smaller differences. However, the situation was overturned as the implant length was increased. Thus, at 20° of knee flexion, when the implant was lengthened in a range of 1–2mm, the laxity observed with fixation mode B was similar to that recorded when the ACL was intact, whereas the laxity observed with fixation mode A was about 3–4mm greater. Similar data were observed at 90° of knee flexion. It appears that fixing the implant finally by applying a tensile load on it while simultaneously pushing the tibia posteriorly could be an effective measure against the possible return of joint laxity.

Leeds-Keio artificial ligament: a new concept for the anterior cruciate ligament reconstruction of the knee.

The features of the Leeds-Keio artificial ligament, which was developed as a collaborative project between the University of Leeds in the UK and Keio University, are introduced. The ligament is made of polyester, and has a mesh structure. The diameter of the polyester fibers is 22 microns. The ligament has a tensile strength sufficient for anterior cruciate ligament (ACL) reconstruction, and fatigue tests have shown satisfactory durability of the ligament. The stiffness of the Leeds-Keio artificial ligament is about 200 N/mm, which is similar to the natural ACL. A combination of a bone plug and stapling is used for the bone fixation, taking into consideration the strength in both the initial mechanical fixation and the long term fixation. From an animal study, it was shown that fibrous tissue was induced around the artificial ligament, and the collagen fibers became aligned in the longitudinal direction of the ligament. For the clinical experience, one-hundred and thirty five cases were reviewed. The Lachaman sign disappeared in 87.4%, and the pivot shift sign disappeared in 88.1%. Side-to-side difference of anterior displacement of the knee, measured with a KT-2000 knee arthrometer at 30 degrees of flexion, was less than 3 mm in 85.9%. More than 90% of the patients experienced full range of motion. Thus, from the clinical results, it can be concluded that reasonable stability was obtained with the operation. If the Leeds-Keio artificial ligament may not be the perfect substitute for the ACL, both experimental and clinical studies indicate that it represents a major forward step in the history of knee ligament surgery.

Simultaneous Reconstruction of the Anterior and Posterior Cruciate Ligaments with Leeds-Keio artificial ligament : A Long-term Follow-up Study

Simultaneous Reconstruction of the Anterior and Posterior Cruciate Ligaments with Leeds-Keio artificial ligament : A Long-term Follow-up Study

Anterior Cruciate Ligament Reconstruction with the Leeds-Keio Artificial Ligament

The Leeds-Keio (L-K) artificial ligament, developed for knee ligament reconstruction, is made of polyester with a maximum tensile strength of 2200 N. This implant works not only as a ligament but also as a scaffold onto which natural tissue grows from synovium. In an animal experiment, each strand of the L-K ligament was covered with new tissue by 2-3 weeks after anterior cruciate ligament reconstruction. Eight weeks postoperatively, abundant fibrous tissue with extensive vascularity covered the implant, which was still histologically immature. After 16 weeks, vascularization and tissue induction began to subside, and histologic analysis showed dense fibers running longitudinally and parallel. By 36 weeks, the new ligament looked like a natural anterior cruciate ligament, although histologically more cells could be seen than in the natural ligament. This maturation was observed only when the substitute was implanted under good tension. Clinically, the surgical procedure has been improved over the past 10 years, to the current practice in which the tape-in-tube double L-K ligament employs a small piece of autogenous tissue to promote early tissue induction and maturation. Using this practice (n = 135), more than 85% of the patients were satisfied subjectively, objectively, and arthroscopically at the 5-year postoperative FU period. Few patients had joint effusion postoperatively. Sacrifice of autogenous tissue is minimal. The patient can return to activities of daily living within 2 weeks, and more than 50% of them to sports within 10 weeks, and the new ligament is expected to keep its function for a long period as ingrowth completes the structure biologically.

Follow-up study of anterior cruciate ligament reconstruction with Leeds-Keio artificial ligament

Follow-up study of anterior cruciate ligament reconstruction with Leeds-Keio artificial ligament

Anterior cruciate ligament reconstruction and physiological joint laxity: earliest changes in joint stability and stiffness after reconstruction

Physiological joint laxity is an important element of normal knee joint function, providing smooth joint movement. However, the objective evaluation of post-operative results after knee ligament surgery is usually based primarily on stability and range of motion, and joint laxity has been ignored. In this study, we measured the joint stiffness of 82 knees undergoing anterior cruciate ligament (ACL) reconstruction with the Leeds-Keio artificial ligament, before the operation, immediately after the operation, and finally when the full range of motion was achieved postoperatively; changes in joint laxity after the ACL reconstruction were investigated. Before the operation, joint laxity was greater than that of the normal side (P < 0.01), but immediately after the operation it diminished compared not only with that observed preoperatively, but also with that of the normal side. When the full range of motion was achieved, joint laxity was lower than that observed immediately after the operation (P < 0.01), but still remained higher than that of the normal side (P < 0.01). In other words, stability was achieved, but joint laxity was diminished through the operation. In this series, a stiffer artificial ligament than the natural ACL was used, and maximum tension was applied during the operation, aiming at better stability, but this may cause diminution of joint laxity.

Posterior Stabilization of Degenerative Lumbar Spondylolisthesis With a Leeds-Keio Artificial Ligament

The biomechanical characteristics of the Leeds-Keio artificial ligament (Neoligament LTD, England) were assessed in the posterior stabilization of degenerative lumbar spondylolisthesis in a porcine vertebral model. To evaluate the biomechanical properties of this nonrigid system immediately after instrumentation and during cyclic loading. Mochida et al reported an innovative method of posterior stabilization in which the Leeds-Keio artificial ligament was used as a nonrigid instrument. Since 1990, this system has been used successfully to treat a select group of patients with degenerative lumbar spondylolisthesis. Five porcine motion segments (L4-L5) were tested in the intact, destabilized, and Leeds-Keio-instrumented conditions. Specimens were loaded in flexion and extension, and construct stiffness was measured during the initial loading cycle and at 250 cycle intervals for 1500 cycles. Biomechanical stability in the model of degenerative lumbar spondylolisthesis was inferior to that in the controls. The instability in the Leeds-Keio group significantly improved immediately after placement and after 1500 cycles. This system is effective in initially stabilizing an unstable degenerative lumbar spondylolisthesis model and maintains its stabilizing effect during cyclic loading. Therefore, it can offer patients with degenerative lumbar spondylolisthesis in the late static stage several advantages over other treatment methods.