PLLA threads

INTRODUCTION: Bioabsorbable screws are, at the expense of metal screws, increasingly used as fixation device in ACL-reconstructions. The possible advantages with bioabsorbable screws are better postoperative MRI evaluations and easier revision surgery. PURPOSE: The aim of this study was to compare the clinical outcome after ACL-reconstructions with BPTB-grafts fixed with metal interference screws or bioabsorbable screws 7 years postoperatively. The resorption of the bioabsorbable screws was also analyzed...

In this work, drug-loaded fibers and threads were successfully fabricated by combining electrospinning with aligned fibers collection. Two different electrospinning processes, that is, blend and coaxial electrospinning, to incorporate a model drug tetracycline hydrochloride (TCH) into poly(L-lactic acid) (PLLA) fibers have been used and compared with each other. The resulting composite ultrafine fibers and threads were characterized through scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, and tensile testing...

The aim of the study was to assess the hard tissue response of a composite hydroxyapatite/poly L-lactic acid (HA/PLLA) interference screw for anterior cruciate ligament (ACL) reconstruction compared to a standard PLLA screw. Twelve skeletally mature rams underwent unilateral ACL reconstruction using an autologous bone-patellar tendon graft. Each animal received either two test HA/PLLA interference screws or two control PLLA interference screws. Animals were sacrificed at 6 and 12 months post-implantation and the operated knees excised...

PURPOSE: To evaluate the long term in vivo degradation of poly-L-lactic acid (PLLA) interference screws with computed tomography (CT) and radiography as used in patellar tendon autograft anterior cruciate ligament (ACL) reconstruction. METHODS: A total of 20 patients who had undergone patellar tendon autograft ACL reconstruction fixed with PLLA screws at least 7 years earlier were evaluated by physical examination, radiography, and CT to determine whether PLLA screw reabsorption and bone ingrowth had occurred...

OBJECTIVE: To assess the treatment effect of intra-articular fracture with absorbable screws and rods. METHODS: From June 1998 to August 2004, 35 patients with intra-articular fracture were treated by absorbable screws and rods made of self-reinforced polyglycolic acid (SR-PGA) and self-reinforced poly-L-Lactic acid (SR-PLLA). Of 35 patients, 30 were males and 5 were females (aged from 4 to 62 years). All cases had intra-articular or periarticular fracture. The interval between injury and operation was 3 hours to 29 days...

The need to provide rigid bony fixation in the surgical treatment of craniofacial deformities has inspired an on-going evolution of surgical innovations and implants. Because of the young age of many treated craniosynostosis patients and the unique pattern of cranial vault growth, the extensive implantation of metal devices is potentially problematic. The use of resorbable plate and screw devices offers all of the benefits of rigid fixation without many of their potential risks. Since the introduction of resorbable plate and screw devices in 1996, tens of thousands of craniofacial patients have received implants, but long-term results from a large series have yet to be reported...

The effect of the manufacturing method on the strength retention of self-reinforced poly-L-lactide (SR-PLLA) screws was studied in vitro and in vivo from 3 up to at least 15 weeks. SR-PLLA screws were manufactured from axially oriented SR-PLLA billets by the conventional compression moulding process and an in-house developed machine cutting technique. New machined SR-PLLA screws (thread diameters 4.5 mm and 3.5 mm) were significantly stronger than older compression moulded SR-PLLA screws (4.5 mm and 3.5 mm) in bending and torque strength tests but significantly weaker in shear strength tests...

BACKGROUND: Bioabsorbable thread pin has been used for internal fixation of bone. The results of resection arthroplasty of the lesser metatarsophalangeal (MTP) joints using internal intramedullary fixation with bioabsorbable pins have not been reported. METHODS: Resection arthroplasty of the MTP joints of the lesser toes with poly-L-lactic acid (PLLA) thread pins or Kirschner wires was performed at random in reconstruction of the 87 rheumatoid forefeet (62 patients) with a grommet-protected silicone-rubber implant insertion of the first MTP joint...

STUDY DESIGN: A new cage made from a forged composite of unsintered hydroxyapatite particles and poly-L-lactide (F-u-HA/PLLA) is compared biomechanically with the Ray threaded fusion cage. OBJECTIVES: To compare the stability imparted to the human cadaveric spine by two different threaded cervical cages and the effect of cyclic loading on construct stability. SUMMARY OF BACKGROUND DATA: Threaded cages have been developed for use in anterior cervical interbody fusions to provide initial stability during the fusion process...

The purpose of this research was to develop a bioabsorbable thread for tight fixation of fractured bones and to examine its mechanical performance in an in-vitro simulation study. The thread is a blend of bioabsorbable poly(L-lactic acid); (PLLA) and poly(epsilon-caprolactone); (PCL) fibers and can be tightly connected by fusion welding of the PCL fibers. The tying strength of the PLLA-PCL blend thread was 39.7 N, which was comparable to that of stainless steel wire. A testing machine was fabricated to measure the fatigue strength of the tying by simulating bone fixation...

Growth stimulation by growth hormones or by IGF-1 is well known whereas publications about stimulation of fracture healing with these substances are rare. One of the main effects of IGF-1 is angiopoiesis which consequently may be expected to induce and accelerate the soft tissue callus formation. BMP-2 is a stimulator for osteoclasts and osteoblasts and prepares the osseous reparation. RhBMPs, mostly BMP-2, are already used in the reconstruction of the cranial vault. The main disadvantage of these proteins is the quick inactivation after about 20-30 minutes...

A new poly(L-)lactic acid (PLLA) thread was tested by applying it in fascial closures of male Wistar rats. The tissue reactions around the thread and in the fascial union, and the changes on the surface and the mechanical properties of the thread were evaluated at 1, 3, 6, 12, 28, and 52 weeks following surgery. Histologically, the extension of the general inflammatory reaction and the number of the different cell types did not markedly change during the 52-week follow-up period. The surface of the thread was intact up to 28 weeks when examined with the scanning electron microscope...

The clinical usefulness of biodegradable oriented poly-L-lactide (PLLA) screws for experimental Salter-Harris type 4 fracture in the distal femoral condyle of dogs was evaluated. Bony union of the osteotomized fragment of the condyle was almost completed radiographically and histologically within 1 to 2 months after surgery, suggesting that PLLA screws maintained strength long enough to fix the fragment until bone healing. At 4 to 6 months after surgery, minute fissures were histologically confirmed on the surface of the screw thread, suggesting the early stage of biodegradation and absorption of the polymer...