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At least 307 records · Page 17Linked to original sources
PubMed2001

The influences of molar intrusion on the inferior alveolar neurovascular bundle and root using the skeletal anchorage system in dogs.

The skeletal anchorage system (SAS) was developed as intraoral rigid anchors for open-bite correction by intrusion of molars. Since the application of SAS is a new modality in orthodontic treatment, the influences of radical molar intrusion on the root and the inferior alveolar neurovascular bundle were unknown. The purpose of this research is to verify the effect of molar intrusion on the neurovascular bundle, the level of osseointegration of bone screws, and root resorption. The results of this study showed mandibular molars were intruded 3.4 mm on the average over 7 months in dogs. The miniplates were well stabilized with osseointegrated bone screws and the peri-implant soft tissues showed slight inflammatory changes. Neither nerves nor blood vessels were damaged. Root resorption was observed but was repaired with new cementum. We concluded that the SAS utilizing transmucosal titanium miniplates as an immovable orthodontic anchorage could provide a new modality for molar intrusions without serious iatrogenic problems.

Alveolar Process↗
PubMed1997

Pubic bone suburethral stabilization sling for recurrent urinary incontinence.

A suburethral sling anchored to the posterior-inferior aspect of the pubic bone with bone screws placed transvaginally is described for recurrent urinary incontinence. The technique involves placing a suburethral patch of a synthetic fiber at the junction of the upper one-third and lower two-thirds of the urethra and securing it by titanium bone screws to the posterior-inferior pubis for site-specific urethral support and stabilization of normally positioned continence anatomy. The procedure was performed from August 1990 through December 1991 in 27 patients with recurrent stress urinary incontinence after previous urinary incontinence surgery, of whom 25 patients were followed yearly until August 1994. None of these 25 patients have had a recurrence as of August 1996. The initial success of the pubic bone suburethral stabilization sling merits further study for the cure of urinary incontinence in patients with a hypermobile urethra or low-pressure urethral conditions.

Bone Screws↗
PubMedDate not supplied

Biocompatibility studies of titanium-based alloy pedicle screw and rod system: histological aspects.

BACKGROUND CONTEXT: Few histological studies of pedicle screw and rod systems have been done, and spinal surgery with pedicle screw and rod system is increasing. PURPOSE: To know the biocompatibility of pedicle screw and rod systems histologically. STUDY DESIGN/SETTING: Titanium-based alloy pedicle screws were removed from 20 patients. Histological studies of the tissue response to the screws were performed by light microscopy. PATIENT SAMPLE: Twenty patients, who were diagnosed with burst type spinal fracture, spondylolysis, spondylolisthesis, and lumbar disc herniation. OUTCOME MEASURES: All slides were observed by light microscopy, and inflammation, fibrous tissue formation, and wear debris were evaluated using a subjective scale. METHODS: Before the surgery, plain radiographs were taken to confirm the solid arthrodesis. Histological analysis was divided into four areas and studied using light microscopy. RESULTS: Inflammation and fibrous tissue formation were the main tissue reactions to the implants. No tissue surrounding the implants showed irreversible changes. Fibrous tissue was often observed at the bone-screw interface without direct contact of screw and bone at the muscle-screw interface histologically. Although some titanium debris was observed in both interfaces, no debris of inflammatory cells were seen at 1 cm distance from the screws. The inflammatory response to the screw debris was localized. CONCLUSIONS: Titanium-based alloy pedicle screws produced some metal debris and caused localized inflammation. No adverse tissue reaction was observed around the screws and rods. Direct contact without any fibrous tissue formation at the bone-screw interface was observed in some patients. A titanium-based alloy pedicle screw and rod system is considered biocompatible histologically.

Adult↗
PubMed1998

Fracture risk during pedicle screw insertion in osteoporotic spine.

Although using a larger screw can enhance the stability of screw-bone interface in pedicular screw instrumentation, it may cause pedicle fracture during screw insertion in osteoporotic spine. We investigated structural changes of the pedicle with the advance of osteoporosis and its implication for the risk of pedicle fracture. Bone mineral density of trabecular, subcortical, and cortical bone of pedicle in an osteoporotic group, assessed by peripheral quantitative computed tomography, was significantly lower than that of those in the normal group. Cortical thickness also declined. There were no pedicle fractures in normal vertebrae, but seven (41.2%) fractures were observed among 17 pedicles in osteoporotic vertebrae in which bone mineral density measured with dual-energy x-ray absorptiometry was <0.7 g/cm2 and screw diameter >70% of the outer diameter of the pedicle. Our results suggest that screw diameter should not exceed 70% of the outer diameter of the pedicle in the case of osteoporosis in which vertebral bone mineral density is <0.7 g/cm2.

Aged↗
PubMed1999

[Diagnosis and management of an intraoperative vertebral artery injury].

A patient with cervical myelopathy caused by marked degenerative alterations of the cervical spinal column at the level of cervical vertebrae 3/4 and relative spinal canal stenosis in the area of cervical vertebrae 5-7 was treated in the department of neurosurgery because of progressive myatrophy and paresis of muscles innervated from cervical nerves 5-7. The operation was performed with vertebrectomy of cervical vertebra 6, implantation of a Harms titanium cage with autograft and a plate and spongy bone screw fixation system. There exists an unusual--and not often publicized--complication during this surgical procedure in the area of the cervical spine, namely penetrating injury of the vertebral artery caused by the treatment with a plate and spongy bone screw fixation system. We describe such an injury of the left vertebral artery. The vertebral artery was intraoperatively embolized using mechanical embolization coils.

Bone Plates↗
PubMed2003

Minimal invasive treatment for scaphoid fractures using the cannulated herbert screw system.

Internal fixation of scaphoid fractures avoids the problems associated with prolonged plaster immobilization and, at the same time, allows an early return to activity for these mostly young patients.Internal fixation of the scaphoid is greatly facilitated by the use of specially designed headless bone screws, such as the Herbert bone screw, originally developed specifically for internal fixation of the scaphoid; furthermore, the advent of cannulated scaphoid screws has made closed (percutaneous fixation) stabilization of the scaphoid a reality. Indeed, this method has now become the treatment of choice for the majority of acute scaphoid fracture, bringing with it all the advantages of internal fixation without the disadvantages of open surgery.However, the success of closed treatment is also dependent on an accurate assessment of the fracture, and for this reason, we now advocate the routine use of computed tomography preoperatively. Because of the complex, 3-dimensional shape of the scaphoid, simple x-rays alone are inadequate, whereas computed tomography, parallel to the long axis of the scaphoid, allows excellent visualization of the fracture and any associated deformity, which must be corrected at the time of surgery.We describe here our method of treating acute scaphoid fractures, and we report the outcome of minimally invasive fixation.

Journal Article↗
PubMed2003

Clinical evaluation of stereotactic brain biopsies with an MKM-mounted instrument holder.

OBJECT: The aim of this study was to assess the clinical usefulness and accuracy of robot-assisted frameless stereotactic brain biopsies with a recently introduced MKM-mounted instrument holder. METHODS: Twenty-three patients with intracranial lesions participated in this study. Depending on the size of the intracranial lesion, fiducials for image-to-patient co-ordinate transformation consisted either of bone screws or adhesive markers. Shortly after surgery, postoperative MRI-imaging was performed to demonstrate the location of the biopsy site. These images were compared with the preoperative images to assess the biopsy localisation error. RESULTS: Postoperative biopsy sites could be demonstrated in six patients with bone screws and in 14 with adhesive markers. These two subgroups yielded average biopsy localisation errors of 3.3 mm (SD 1.7 mm) and 4.5 mm (SD 2.0 mm) respectively. This difference was not statistically significant. One biopsy was located in a liquefied haematoma. All others yielded pathological tissue. There were two postoperative haemorrhages, of which only one was temporarily symptomatic. There was no mortality in the first 30 days after surgery. CONCLUSIONS: Robot-assisted frameless point-stereotactic techniques represent an alternative to frame-based techniques for the performance of stereotactic biopsies.

Adult↗
PubMed2003

[Two rare complications in patients with bone-anchored hearing aids].

In our program of bone-anchored hearing aids we experienced two rare complications: a child with a hearing aid fell on her head and got an intrusion of the bone-screw into the intracranial space with a fracture of tabula externa and interna. There were no further intracranial complications, no hematoma or infection. The screw was explanted immediately with oto-microsurgical instruments and diamond burrs. The site of the screw was covered with a local skin flap. There were no complications in wound healing and the child got a second implant on the other side. A patient got an infection of his bone fixation screw and we took out the external fixation but left in place the bone screw, which was obviously still well fixed and the adjacent bone was without signs of infection. There was good secondary wound healing with local and systemic antibiotics. With almost completely healed external wound the patient got an intracranial abscess, that needed neurosurgical drainage. After long-time antibiotic treatment the patient is well again.

Abscess↗
PubMed1982

Rigid compression screw fixation of first proximal phalanx osteotomy for hallux abducto valgus.

Various external and internal immobilization techniques have been employed when performing a medial closing wedge osteotomy at the first proximal phalangeal base for the correction of hallux abducto valgus. Internally, the techniques used such materials as absorbable and nonabsorbable suture, monofilament stainless steel wire, osteoclasps, ministaples, and Kirschner wires. In this study, we have employed the A.O.3 technique of rigid compression screw fixation across the osteotomy site. Three different types of screws were utilized; 3.5-mm. and 4-mm. Bechtol screws and 2.7-mm. cortical bone screw, all of which were 3 cm. in length. Eight procedures were performed for six patients. The authors found the benefits afforded by rigid fixation according to the A.O. technique with respect to the production of postoperative callus at the osteotomy site to be superior in comparison to other modalities of fixation.

Adult↗
PubMed2002

[Suburethral sling for male urinary incontinence].

This article describe a new technique for treating post-prostatectomy urinary incontinence. We performed this procedure on 15 patients with a follow-up of 2 to 9 months. All of the patients had radical retropubic prostatectomies and a urodynamically confirmed stress urinary incontinence for more than one year; 3 of the 15 (20%) had detrusor instability. We used the exaggerated lithotomy position and a perineal approach. Three 5 mm titanium bone screw with pre-loaded No 1 polypropylene sutures (In fast Straight-In bone Screw Suture system) were placed on each side of the inner surface of the descending pubic ramus. To support the bulbar urethra was used a cadaveric fascia lata graft, reinforced with a piece of folded polypropylene mesh and tied to the pubic bone using the sutures attached to the bone anchors. Urethral resistance was increased to 45 cm H2O above baseline pressure. Thirteen patients (86.6%) are completely cured, i.g., do not require any pads. We have seen total failure in 1/15 patients (6.6%) and minimal improvement in 1/15 patients (6.6%). Urgency incontinence was reported in 3/15 patients (20%). All responded to the use of anticholinergic therapy. Two of the three patients with post-operative urgency incontinence had preoperative detrusor instability documented on urodynamic evaluation. This minimally invasive male sling procedure is efficacious. Long-term follow-up will be necessary before a final assessment of this new technique is rendered.

Follow-Up Studies↗
PubMed1989

The effects of pre-tapping on the miniscrew-bone interface in the midface.

The effects of pre-tapping on the AO miniscrew-midface bone interface were investigated in 140 methacrylate-fixed human cadaver specimens. An adequate contact was found in all 40 self-tapped and in 68 out of 100 pre-tapped samples. Since inadequate contact was found in the remaining 32 specimens from the pre-tapped group, it was concluded that the pre-tapping was responsible for the inadequate bone screw interface.

Bone Screws↗
PubMedDate not supplied

Surgical management of proximal splint bone fractures in the horse.

Fractures of Metacarpal and Metatarsal II and IV (the splint bones) were treated in 283 horses over an 11 year period. In 21 cases the proximal portion of the fractured bone was stabilized with metallic implants. One or more cortical bone screws were used in 11 horses, and bone plates were applied in 11 horses. One horse received both treatments. Complications of screw fixation included bone failure, implant failure, radiographic lucency around the screws, and proliferative new bone at the ostectomy site. Only two of the horses treated with screw fixation returned to their intended use. Complications of plate fixation included partial fixation failure (backing out of screws), wound drainage, and proliferative bony response around the plate. Six of the 11 horses treated by plate fixation returned to their intended use. The authors recommend consideration of plate fixation techniques for repair of fractures in the proximal third of the splint bone.

Animals↗