Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Bone Nails”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed1997

Lumbosacral arthrodesis using pedicular screws and ringed rods.

Sixty-one patients who had lumbar instability and chronic low back pain or deformity from nontraumatic lumbar pathologies were studied. In all of them a posterior lumbosacral fusion with CUN (Clinic of the University of Navarre) pedicle rod fixation was used. The mean follow-up period was 36 months (range 26-46 months). The consolidation rate was evaluated according to plain and functional radiographs, and a clinical evaluation was made using an analogue pain scale. The rate of fusion was 93.5%. Neurological complications occurred in 3.3%. The incidence of screw failure was 2.3% of all the screws. No other implant failure occurred. The patients rated their clinical results as 'excellent' in 33.8% of the cases, 'good' in 42.2%, 'fair' in 16.9% and 'poor' in 6.7%. CUN instrumentation is a versatile internal fixation system that has been shown to provide satisfactory stability. Furthermore, the clinical results are comparable to those reported in studies in which the most common hardwares were used.

Adolescent↗
PubMed1998

Anterior tibial artery and its actual projection on the lateral aspect of the tibia: a cadaveric study.

The anterior tibial artery (ATA) is at risk of injury during high tibial osteotomy, Ilizarov wire placement, pin placement in external fixation, or proximal locking screw insertion, as the artery is not visualized intraoperatively. The ATA is anchored to the oval foramen of the interosseous membrane on the proximal tibia by the deep fascia and recurrent genicular vascular branches. Segment 1 (from the bifurcation of the popliteal artery to the level of the interosseous foramen) and the proximal part of segment 2 (from the interosseous foramen to the level where the artery crosses the anterior border of the tibia) may be damaged when pin, wire or screw placement is directed posterolaterally at that level. Distally, a straight mediolateral pin or Ilizarov wires may lacerate the artery. Segment 2 of the ATA descends against the interosseous membrane in its proximal part, which is projected on the posterior third of the tibia relative to the sagittal plane; in its middle part, it runs close to the lateral cortex of the tibia, it is projected on the middle third of the tibia; in its distal part it runs gradually towards the anterior third of the tibia and contacts with the anterior third of the tibial cortical surface. This information may help reduce risk of injury to the ATA during high tibial osteotomy, external fixation and pin placement or insertion of locking screws.

Bone Nails↗
PubMedDate not supplied

The effect of blood flow on the material properties of bone.

This project was undertaken to establish if the integral circulation had any effects upon the mechanical behavior of bone. The influence of blood flow in the rabbit tibia on the strain induced at the bone surface when under load was assessed. Recordings were taken from three adult and three immature New Zealand White rabbits which had previously had both their tibiae pinned with modified orthopedic pins. Strain readings were obtained from the exposed mid-shaft of the tibia of both hind legs before, during and after blood flow changes. The loading was static and used to maintain a strain of 250 mu strain in adult animals and 180 mu strain in immature animals prior to variation in blood flow. The blood flow was altered by means of a tourniquet inflated to 80 mm Hg and placed medial to the pinned tibia; it was inflated for a specific time (approximately 40 minutes) during the experimental loading. Reducing the blood flow appeared to alter the strain recorded at the bone surface while the applied load across the pins remained constant. An initial effect when there was reduced perfusion was that the strain increased following a reduction in blood flow. The strain then began to decrease in magnitude on the compressive aspect coincident with release of the cuff to a level below the value of the initial normally perfused bone. Upon return of the blood supply to normal levels following the initial hyperaemic phase, the strain value increased to a value comparable with that of normally perfused bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

[Defective shaft positioning in medullary nailing as a result of play of the nail--a biomechanical analysis].

The influence of the nail wall thickness on the stress distribution is shown for the AO-nail as well as the Küntscher-nail. The quality of the analytical solution is proved by demonstrating that the presence of the slot in the nail does not shift the bending stresses merely. The gap between nail and bone is shown to be responsible for misalignments in the fracture.

Biomechanical Phenomena↗
PubMed2006

Parameters affecting primary stability of orthodontic mini-implants.

AIM: Treatment options in orthodontics have been expanded by skeletal anchorage via mini-implants over the last few years. Sufficient primary stability is imperative to minimize implant loss rate. The aim of this study was to quantitatively analyze the factors influencing primary stability: bone quality, implant-design, diameter, and depth of pilot drilling. MATERIAL AND METHODS: Thirty-six pelvic bone segments (ilium) of country pigs were dissected and embedded in resin. To determine the primary stability, we measured the insertion torque of five different mini-implant types (tomas-pin [Dentaurum, Ispringen, Germany] 08 and 10 mm, and Dual Top [Jeil Medical Corporation, Seoul, Korea] 1.6 x 8 and 10 mm plus 2 x 10 mm). Twenty-five or 30 implants were inserted into each pelvic bone segment following preparation of the implant sites using pilot drill diameters of 1.0, 1.1, 1.2 and 1.3 mm and pilot drill depths of 1, 2, 3, 6 and 10 mm. Five implants were inserted for reference purposes to establish comparability. Thicknesses of bone compacta were measured via micro-computer tomography. RESULTS: Insertion torques of orthodontic mini-implants and therefore primary stability varied greatly, depending on bone quality, implant-design, and preparation of implant site. Compared with the tomas-pin, the Dual Top screw showed significantly greater primary stability. Torque moments beyond 230 Nmm caused fractures of 9 Dual Top screws. CONCLUSION: Compacta thickness, implant design and implant site preparation have a strong impact on the primary stability of mini-implants for orthodontic anchorage. Depending on the insertion site and local bone quality, the clinician should choose an optimum combination of implant and pilot-drilling diameter and depth.

Animals↗
PubMed2005

Compass hinge fixator for acute and chronic instability of the elbow.

OBJECTIVE: To maintain concentric reduction of an unstable elbow and to allow active exercises after the treatment of complex elbow injuries or their sequelae. INDICATIONS: Recurrent dislocation or subluxation of the elbow after repair or reconstruction of bony, capsuloligamentous, and/or musculotendinous stabilizers. Tenuous fixation of large coronoid fractures due to fragmentation or osteopenia. Stabilization of the joint after fascial arthroplasty or debridement for infection, if the debridement destabilizes the elbow. Relative indication: maintenance of range of motion after release of contractures. CONTRAINDICATIONS: Absent patient compliance. Lack of familiarity of surgeon with elbow anatomy and function as well as with hinged external fixation techniques. SURGICAL TECHNIQUE: Preferably posterior longitudinal midline incision. Placement of axis pin in the center of rotation of the distal humerus. Application of the fixator over this wire. Placement of Schanz screws into humerus und ulna taking care to protect the radial and ulnar nerves. Removal of axis pin. Rechecking of entire frame and tightening. RESULTS: The authors' experience with the Compass Hinge Fixator documents restoration of stability and excellent motion after relocation of a chronic simple elbow dislocation, a useful role in reconstructing acute and chronic elbow instability after fracture-dislocation, and a limited role in restoring mobility after severe contracture release.

Acute Disease↗
PubMed2006

A hinged external fixator for the elbow.

OBJECTIVE: Stabilization of the ulnohumeral joint against rotation and shear forces, preserving flexion and extension movements, in order to safeguard the healing of the collateral ligaments. INDICATIONS: Persistent instability of the elbow joint in 90 degrees flexion following elbow dislocation, particularly in the anteroposterior direction; dislocation fractures; arthrolysis and graft arthroplasties; closed distraction arthrolysis. CONTRAINDICATIONS: Local infection in the area of the planned Schanz pins, uncertain position of the neurovascular structures, and lack of experience with the external fixator. SURGICAL TECHNIQUE: Determination of the joint axis through the capitulum of the humerus and the trochlea. Insertion of a 3-mm Kirschner wire (reference pin) in the center of rotation. Insertion of the humeral and ulnar Schanz pins under direct vision from the lateral or medial aspect. The lateral humeral Schanz pins are inserted in the distal humerus dorsal to the radial nerve. Removal of the reference pin. Symmetrical distraction of the ulna 2-3 mm from the joint surface of the humerus with the aid of the distractor. POSTOPERATIVE MANAGEMENT: No immobilization, immediate start on active and passive physiotherapy under plexus anesthesia, depending on the soft-tissue situation, individual pain, and the extent of the surgical procedure. RESULTS: The case histories of ten patients treated for persistent instability of the elbow at 90 degrees flexion or for an old dislocation of the elbow between April 2001 and March 2003 were studied retrospectively. The average age was 51 years (40-62 years). In seven patients internal fixation of the elbow had to be performed, six of which were treated initially with an AO fixator. After an average of 8 days the management was changed to hinged fixation. The median Mayo Elbow Function Score was 78 points with two very good, three good, and five satisfactory results. Subjective satisfaction on the DASH Score (Disabilities of Arm, Shoulder and Hand) revealed a slight reduction by an average of 18 points.

Adult↗
PubMed2002

[Development of new, biodegradable implants].

The advantage of biodegradable implants is that they do degrade after they have fulfilled their function. Therefore, a second operation for removing metal implants is not necessary. Additionally, the healing process may be stimulated by the successive loss of the mechanical properties of the implant during degradation, corresponding with the increasing loading on the healing tissue. The most important materials are polylactide, polyglycolide and their copolymers, and polydioxanone. The mechanical properties of these polymers were improved by special fabrication techniques. Nevertheless, the materials have disadvantages relating to their stiffness and relaxation behavior. Therefore, their use has to be restricted to nearly unloaded situations. The degradation behavior of the materials can be controlled by the production of copolymers and by the molecular weight of the polymers. The degradation behavior cannot be predicted exactly in vivo, as it is influenced not only by the chemistry and the implant design but also by the localization of the implant in the tissue. In general, the biocompatibility of the polymers used today is good and the observed complication rate is very low. Osteolytic reactions, which can sometimes be observed, have no clinical consequences in most instances. The clinical applications comprise resorbable pins and screws for the fixation of small bony fragments, interference screws for the surgery of the anterior cruciate ligament, resorbable augmentation devices for ligaments and tendons, resorbable membranes for guided bone regeneration in maxillofacial surgery, and a lot more. Future developments are expected in the field of tissue engineering and drug release.

Absorbable Implants↗
PubMed2002

[New techniques for bone synthesis on the humerus].

Fractures of the upper arm near the shoulder are common. A consensus on treatment only occurs for simple, un-dislocated fractures and with the complete destruction of the concha in elderly people. For most of the 2-4 component fractures, there exist a variety of, in part contradictory, recommendations in the literature. The most diverse statements mirror the conflict between the best anatomical solution and the practically most stable position with the least possible additional damage of the surrounding structures through surgery. Whether the implants with the most stable angle using the latest generation of plates will lead to an improvement in the results is at present a matter under clinical study. The indications are clearer for the shaft. The development of the latest plates and intramedullary implants provides a surgical improvement, and implant specific complications (e.g., pin movement) will be reduced with further development. Whether there are also advantages for the patient remain to be seen.

Aged↗
PubMed2000

[Current aspects of anchoring hamstring tendon transplants in cruciate ligament surgery].

The use of hamstring tendon grafts in cruciate ligament surgery has recently raised strong interest. Hamstring tendons are superior to the mid third patellar tendon graft by virtue of lower harvest site morbidity combined with high tensile strength. Osseous graft incorporation relies on a proper tendon-to-bone healing, which relies on specific biomechanical and biological boundary conditions. Several different fixation devices have recently been introduced, with special emphasis on high initial fixation strength and moving the level of fixation closer to the joint line, the so-called aperture fixation. The goal of the present review is to focus on the advantages and disadvantages of different fixation principles for hamstring tendon grafts in order to give a comprehensive insight into current developments, such as interference fit fixation, cross-pin fixation, and the concept of hybrid fixation.

Anterior Cruciate Ligament↗
PubMed2003

[Influence of processing and sterilization on the mechanical properties of pins made from bovine cortical bone].

In a biomechanical study pins made of xenogenous cortical bone were tested in vitro. Forty pins of 3 mm diameter and 60 mm length were made of eight different cattle tibiae and allocated to five different treatment groups. Freeze-dried pins served as control group. Pins of the second group were preserved in concentrated sodium chloride solution and defatted with acetone (Tuto-plast processing). Pins of groups three to five were treated with sodium chloride and acetone and afterwards sterilized by different means (ethylene oxide, autoclavation, or gamma radiation). All pins were subjected to a three-point-bending test and a shear test. We found that bending strength and shearing strength were most increased after sodium chloride and acetone treatment, whereas after sterilization with ethylene oxide or autoclaving, the stability of the pins was similar to the control group. The stability was considerably diminished after gamma radiation. Taking into account possible toxic side effects of ethylene oxide, we conclude that Tutoplast processing followed by autoclavation presents a reliable preparation method for the clinical use of implants made of bovine cortical bone.

Acetone↗
PubMed2003

[Fractures of the humeral head].

Fractures of the humeral head are very common in elderly people, with 70% of all such fractures being seen at an age of more than 60 years. For the radiological examination of the fracture, x-rays from two levels are mandatory. The number and position of the fragments, assessment of intact or ruptured periosteum between the fragments and muscle forces acting on the fragments have to be determined from the x-rays. A 3-D CT scan can be very useful for better understanding of the character of the fracture. The remaining displacement between fragments after reduction have to be evaluated according to their location. Even small incongruities between fragments in the subacromial space will impair the gliding mechanism, whereas remaining displacements between the head and shaft can be accepted to a much larger extent. According to the fracture mechanism, we can basically differentiate between avulsion fractures and depression fractures. The avulsion fractures are characterised by a varus tendency of the humeral head,whereas the depression fractures are characterised by a valgus position of the head fragment. This has to be taken into consideration when choosing the implant for fixation. The indication for reconstructive surgery or prosthetic replacement depends on the type of fracture, on the quality of bone and on the familiarity of the surgeon with the treatment of humeral head fractures. The implants currently used for fixation can basically be differentiated between rigid and semi-rigid. The indication for the one or the other depends on the fracture type and the bone quality. In general, for simple fractures and in case of poor bone quality semi-rigid implants are indicated. Despite the fact that an understanding of the character of the fractures and implants has improved over the last few years, there are still types of fractures which need primary prosthetic replacement.

Age Factors↗
PubMed1997

[Transoral metal implant removal after ventral C2/C3 spondylodesis in pharyngo-vertebral fistula].

A 26-year-old man sustained a C2 arc fracture. Ventral spondylodesis using an H-plate was performed. The patient developed a pharyngovertebral fistula which remained undetected for 1 year. Spontaneous fusion of C3/C4 and osteolysis of the cortical block occurred. The fistula was demonstrated intraoperatively and the implant was transorally removed. No further problems occurred after this unusual method of treatment. The anatomy of the cervical spine, special problems of intensive care patients and the use of proper instrumentation are discussed.

Adult↗