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PubMed2003

Temporomandibular joint morphology changes with mandibular advancement surgery and rigid internal fixation: a systematic literature review.

The purpose of this systematic review was to evaluate the effect of bilateral sagittal split mandibular osteotomy (BSSO) with rigid internal fixation (RIF) on temporomandibular joint (TMJ) morphology. Controlled trials of BSSO with RIF treatment of Class II patients using transcranial radiographs, submental vertex (SMV) radiographs, tomographic radiography, computed tomography (CT) scan, or magnetic resonance imaging (MRI) to assess TMJ morphology were identified by Medline (1966-2001) and PubMed. Case reports were excluded. On the basis of our search only six studies were included in this review. All studies used internal controls with pre- and posttreatment imaging. Two studies used SMV, one used transcranial radiographs, one used tomography, two used CT scan and one used MRI. Methodological deficiencies prevent major conclusions regarding osseous remodeling and disk status. There was a wide range of individual variability in condyle position change. The reviewed studies have highlighted the importance of further research. Prospective controlled studies using serial MRI and tomography or CT scan are required to establish effect of BSSO with RIF on TMJ morphology.

Adult↗
PubMed1985

A new device for internal fixation of thoracolumbar and lumbar spine fractures: the 'fixateur interne'.

A new system of operative fixation of thoracolumbar and lumbar spine fractures is presented: the 'fixateur interne' (F.I.). From a posterior approach long Schanz screws are inserted through the pedicles into the body of the two vertebrae just adjacent to the lesion and connected by th threaded F.I. rods. By tightening the nuts the Schanz screws are fixed in all directions. The advantages of the F.I. system are: excellent reposition by the long lever-arm of the Schanz screws, immobilization of only two segments and therefore good mobility of the residual spine, stability against flexion forces better than is obtained with Harrington distraction rods, additional rotational stability, and fixation in lordosis or kyphosis as is desired. The F.I. does not act as a four point bending system like all other dorsal spine instrumentation systems, but provides stability in flexion by itself. Therefore it can be Used independently of the condition of all ligaments (including the anterior longitudinal ligament) and of the posterior wall of the fractured vertebrae, and there is no need to fix more than the two immediately adjacent vertebrae, thus avoiding the often painful and cumbersome iatrogenic loss of lumbar lordosis and of mobility and permitting early mobilization of the patient. Experience with the first 45 patients is very promising.

Bone Screws↗
PubMed1995

Telemeterized load measurement using instrumented spinal internal fixators in a patient with degenerative instability.

STUDY DESIGN: In the present study, the loads in an internal spinal fixation device were measured in vivo. OBJECTIVES: To determine the implant loads for different activities before and after additional anterior stabilization of the spine. SUMMARY OF BACKGROUND DATA: Mathematical models exist for predicting spinal loads. The intradiscal pressure has been measured for many body positions and activities. The loads on internal spinal fixation devices have not been measured before in vivo. METHODS: Telemeterized AO spinal internal fixators were implanted in a patient with degenerative instability. The implants allow the in vivo measurement of three force components and three moments acting in the implant. RESULTS: When the patient was lying in relaxed positions, the implant loads were small. Before additional anterior stabilization, the loads were also small for sitting, standing, and walking. The bending moment in the sagittal plane was less than 3 Nm for these activities. The highest loads within the first 4 weeks after implantation were measured while the patient turned from a supine to a lateral position against the advice of the physiotherapist. After anterior stabilization, the maximum loads for the relaxed lying positions were altered only slightly. Much higher axial forces and bending moments were measured for sitting, standing, and walking. The maximum bending moment increased to 5-8 Nm for these activities. The implant loads for sitting were not higher than for standing. CONCLUSION: Flexion and lateral bending of the upper body and weight-carrying during sitting, standing, or walking should be avoided in the first few months after anterior stabilization.

Bone Screws↗
PubMed1995

[Surgical treatment of thoracolumbar spinal fractures with internal fixator and transpedicular spongiosa-plasty].

We report on 30 unstable fractures of the thoracolumbar spine which were operatively treated between 1987 and 1992 with the AO Internal Fixator and transpedicular bone grafting. There were 26 flexion-compression fractures, 2 flexion-distraction injuries and 2 fracture-dislocations. Follow-up ranged from 2 to 5 years. All patients were examined and their histories reviewed. New radiographs were obtained and a standardized questionnaire on pain and on functional and economical status was answered. The radiographical analysis included measurement of the vertebral, segmental and local kyphosis and of the sagittal index. The preoperative vertebral kyphosis averaged +17 degrees and was corrected to +7 degrees at follow-up with the sagittal index improving from 0.59 to 0.86. The segmental respectively local kyphosis was reduced from +15 degrees respectively +8 to +5 degrees respectively -3 degrees. The fractured vertebra remained stable. We registered an average postoperative loss of correction of 4 degrees in the upper disc space due to collapse of the injured disc. The lower disc space was frequently overcorrected which was neutralized postoperatively due to a process of reequilibration of less than 3 degrees. The loss of correction occurred both before and after removal of the implant. There was no significant change of the sagittal plane apart from a successful realignment of the flexion-distraction injuries. Five out of 8 patients with neurological symptoms improved by at least 1 Frankel grade. We had no case of neurological deterioration. The results of the questionnaire were good or very good in 70%. At follow-up, the average back pain score was 3 out of 10, 10 being unbearable pain.

Adolescent↗
PubMed1988

Biomechanical evaluation of spinal fixation devices: II. Stability provided by eight internal fixation devices.

The three-dimensional stability provided by eight spinal fixation devices has been studied in an in vitro biomechanical model using seven-vertebrae (T9-L3) fresh cadaveric thoracolumbar specimens. An injury was created at T12-L1 by complete transection of the posterior elements and posterior half of the intervertebral disc, leaving the anterior half of the intervertebral disc and anterior longitudinal ligament intact. The three-dimensional rotational and translational motions, measures of biomechanical instabilities, were determined under physiologic loads for the intact specimen after injury and instrumentation with each of the eight fixation devices. The tested devices were: Dunn's anterior device (DD); Harrington distraction (HD); Harrington compression (HC); Harrington distraction-compression combination (HDC); Harrington distraction with sleeves (HDS); Luque rods (LQ); Luque rectangle (LR); and Luque short rectangle (LSR). The following devices were stable under the four loads: Flexion: HC, HD, HDC, HDS, LQ, and LR; Extension: HD, HDC, HDS, LQ, and LR; Lateral Bending: LQ and LR; and Axial Rotation: none.

Biomechanical Phenomena↗
PubMedDate not supplied

USS internal fixator in lumbar and thoracolumbar vertebral fractures.

The authors report their experience in the surgical treatment of lumbar and thoracolumbar vertebral fractures with the use of the USS-AO internal fixator at the Division of Orthopaedics of the Azienda Ospedaliera OO.RR. in Foggia between July 1996 and July 1998. The cases, although not numerous, confirm the effectiveness of the method of correction and its maintenance even in time.

Adult↗
PubMed1987

Open reduction and internal fixation of vertical shear pelvic fractures.

The goal in the treatment of vertical shear fractures of the pelvis is to achieve and maintain an accurate reduction of the displaced hemipelvis. Open reduction and internal fixation of the posterior pelvic ring injury along with either internal or external fixation of the anterior pelvic ring injury was used in 12 vertical shear fractures in 11 patients. The posterior fixation was aided by accurate definition of the injury pattern, use of preoperative traction, early surgical treatment, use of flexible instruments, and identification of the posterior sacral foramina, which were used as a guide to allow accurate screw placement into the sacrum and avoid nerve root injury. The procedure was not associated with an increased rate of infection or neural injury. In the ten patients followed more than 1 year there were no late displacements of the hemipelvis and all of the fractures healed.

Adolescent↗
PubMed1994

The effect of internal fixation on the healing of large allografts.

One hundred and twenty patients had an allograft reconstruction of the femur, tibia, or humerus. Of a total of 183 allograft-host junctions, eight-three were fixed with a plate; ninety-eight, with an intramedullary rod; and two, with screws alone. There was no significant difference between the rate of union after fixation with a plate and that after intramedullary fixation (p = 1.00). However, fixation with a plate was associated with a higher rate of fracture of the allograft (p < 0.0001). Some problem related to the internal fixation of the allograft was identified at eighteen of the twenty junctions that did not heal. There was a significant association (p < 0.001) between a problem in the achievement of stable fixation and the development of a non-union at the allograft-host junction.

Adolescent↗
PubMedDate not supplied

Internal fixation in unstable fractures of the pelvis. Preliminary notes.

The authors report the preliminary results of the surgical treatment of unstable fractures of the pelvic ring. Between 1989 and 1993 a total of 12 unstable fractures were treated by internal fixation. Short-term radiographic and functional results were satisfactory. The authors attribute an essential role to preoperative planning by conventional radiographic assessment and CT scan with multiplanar reconstructions, associated with carefully performed internal osteosynthesis.

Adolescent↗
PubMedDate not supplied

Mechanical and structural characteristics of the new BONE-LOK cortical-cancellous internal fixation device.

The purpose of this study was to evaluate the structural and mechanical characteristics of a new and unique titanium cortical-cancellous helical compression anchor with BONE-LOK (Triage Medical, Inc., Irvine, CA) technology for compressive internal fixation of fractures and osteotomies. This device provides fixation through the use of a distal helical anchor and a proximal retentive collar that are united by an axially movable pin (U.S. and international patents issued and pending). The helical compression anchor (2.7-mm diameter) was compared with 3.0-mm diameter titanium cancellous screws (Synthes, Paoli, PA) for pullout strength and compression in 7# and 12# synthetic rigid polyurethane foam (simulated bone matrix), and for 3-point bending stiffness. The following results (mean +/- standard deviation) were obtained: foam block pullout strength in 12# foam: 2.7-mm helical compression anchor 70 +/- 2.0 N and 3.0-mm titanium cancellous screws 37 +/- 11 N; in 7# foam: 2.7-mm helical compression anchor 33 +/- 3 N and 3.0-mm titanium cancellous screws 31 +/- 12 N. Three-point bending stiffness, 2.7-mm helical compression anchor 988 +/- 68 N/mm and 3.0-mm titanium cancellous screws 845 +/- 88 N/mm. Compression strength testing in 12# foam: 2.7-mm helical compression anchor 70.8 +/- 4.8 N and 3.0-mm titanium cancellous screws 23.0 +/- 3.1 N, in 7# foam: 2.7-mm helical compression anchor 42.6 +/- 3.2 N and 3.0-mm titanium cancellous screws 10.4 +/- 0.9 N. Results showed greater pullout strength, 3-point bending stiffness, and compression strength for the 2.7-mm helical compression anchor as compared with the 3.0-mm titanium cancellous screws in these testing models. This difference represents a distinct advantage in the new device that warrants further in vivo testing.

Bone Screws↗
PubMed2000

Comparative stability of the "Internal Fixator" and the "Universal Spine System" and the effect of crosslinking transfixating systems. A biomechanical in vitro study.

In this study, the three-dimensional stabilizing capabilities of the AO-Internal Fixator (IF) and the new Universal Spine System (USS) were investigated. Both devices were tested without and with the cross-link system (IF, IFC, USS, USSC). To determine biomechanical characteristics, a human thoracolumbar spine instability model with resection of the vertebral body Th12 was created. The vertebral body was replaced by a spacer and transpedicular posterior stabilization was performed from Th11 to L1. All devices reduced the range of motion (ROM) significantly compared to the values of the intact specimen. In flexion the IFC showed the highest reduction of ROM (85% of intact), followed by the USSC, USS and IF (79% of intact). In extension the ROM was restored again most by the IFC (52% of intact), followed by the USSC, IF and USS (44% of intact). In lateral bending stability was provided by the USSC (right 78% and left 81% of intact), followed in right lateral bending by the IF, IFC and USS and in left lateral bending by the USS, IF and IFC. In axial rotation the ROM was reduced primary by the IFC (right 51% and left 46% of intact), followed in right axial rotation by the USS, USSC and IF, in left axial rotation by the USSC, USS and IF. Additional stability by crosslinking has been provided in the IF and the USS in flexion and extension, in the USS in lateral bending and in the IF in axial rotation nonsignificantly. The neutral zone (NZ) was reduced by posterior instrumentation in flexion/extension and right/left lateral bending significantly. In axial rotation only the USSC decreased the NZ below intact levels. The study showed no statistical significant differences in the stabilizing capabilities of the USS compared to the IF. For both implants the cross-link system increased stability in the chosen instability model insignificantly only.

Aged↗
PubMed1999

Clinical outcome of arthrodesis of the ankle using rigid internal fixation with cancellous screws.

Thirty consecutive patients underwent arthrodesis of the ankle using rigid internal fixation with cancellous screws between 1992 and 1996. One patient died of causes unrelated to the surgery before bony union. Primary fusion occurred in 27 of the remaining 29 patients (93%). The average time to primary union was 9 weeks. Two patients developed a delayed union and were treated with an additional bone-grafting procedure. Ultimately, each of the 29 patients went on to fusion. Use of tobacco during the postoperative period had no apparent effect on the rate of fusion or time to fusion. Twenty-five patients were available for clinical evaluation at an average of 24 months after surgery. Subjective evaluation using questionnaires revealed a high level of satisfaction. All patients stated that they would undergo the procedure again. The mean postoperative score on the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale was 81 points, compared with 48 points preoperatively (of a possible 100). Constant pain was the reason given by all patients for seeking treatment. After the arthrodesis, pain was reported as absent in 13 and occasional in 12 patients. All patients noted less pain in the hindfoot after fusion of the ankle. Active litigation and Workers' Compensation claims during the perioperative period had a significant negative effect on scores on the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale and seemed to decrease patients' perceived ability to return to work.

Adult↗
PubMed1993

Function 10 years after hip fracture. 74 patients after internal fixation.

We examined the physical and social function of patients surviving 10 years after internal fixation of a hip fracture. 74 out of 362 patients were alive 10 years after their fracture. In 47 survivors after cervical fracture, secondary hip arthroplasties had been performed in 25, and nails had been extracted in 13. The implants had been removed in 8 of 27 with trochanteric fracture. 58 survivors were interviewed; three fourths were still living in their own homes, with more than half needing no home assistance. However, limitation of activities, caused by the fracture, was experienced by more than one third of the survivors.

Adult↗
PubMed2000

The use of pedicle-screw internal fixation for the operative treatment of spinal disorders.

Pedicle screws have dramatically improved the outcomes of spinal reconstruction requiring spinal fusion. Short-segment surgical treatments based on the use of pedicle screws for the treatment of neoplastic, developmental, congenital, traumatic, and degenerative conditions have been proved to be practical, safe, and effective. The Funnel Technique provides a straightforward, direct, and inexpensive way to very safely apply pedicle screws in the cervical, thoracic, or lumbar spine. Carefully applied pedicle-screw fixation does not produce severe or frequent complications. Pedicle-screw fixation can be effectively and safely used wherever a vertebral pedicle can accommodate a pedicle screw--that is, in the cervical, thoracic, or lumbar spine. Training in pedicle-screw application should be standard in orthopaedic training programs since pedicle-screw fixation represents the so-called gold standard of spinal internal fixation.

Adult↗
PubMed2004

Internal fixation of radial neck fractures: an in vitro biomechanical analysis.

OBJECTIVE: To assess the fixation rigidities of a custom designed blade plate, a 2.7 mm T-plate and 3.0 mm cannulated screws. DESIGN: A cadaveric non-comminuted radial neck fracture model was employed to test the three fixation methods, using a multi-directional shear loading protocol. BACKGROUND: The management of displaced radial neck fractures in adults remains unsatisfactory due to failure of internal fixation with secondary loss of reduction, and non-unions. METHODS: The stiffness of the various fixation methods was measured in five directions of loading in the transverse plane. Failure testing was performed on the final testing condition for each specimen, in a posteroulnar to anteroradial direction. RESULTS: The direction of specimen loading did not have a significant effect on the stiffness of the various methods of fixation (P = 0.4). There was no significant difference in the fixation stiffness between the 3.0 mm screws or blade plate, however, both were superior to the T-plate (P < 0.05). CONCLUSIONS: Although the 2.7 mm T-plate has been reported in the literature as a viable method of fixation for radial neck fractures, it may not be optimal from the viewpoint of fixation stability. In the setting of a non-comminuted radial neck fracture, the use of cross-cannulated screws or blade plate fixation is preferred.Relevance This study supports the use of cross-cannulated screws or blade plate fixation for non-comminuted fractures of the radial neck.

Aged↗
PubMed1994

Acetabular fractures: long-term follow-up of open reduction and internal fixation.

Eight-seven acetabular fractures in eighty-seven patients underwent open reduction and internal fixation at Vanderbilt University Hospital from 1984 to 1989. Fifty-six were treated by orthopaedic traumatologists. Fifty-six patients returned for long-term follow-up (range 24-80 months, average 43). Harris hip ratings were used to clinically grade the results. Poor results were found in 43%. Eighty-three percent of the patients with poor results had satisfactory surgical reductions with < 3 mm of residual displacement. Factors other than surgical reduction contributed significantly to the poor results. These included hip dislocation associated with the fracture, class III or IV heterotopic ossification, development of avascular necrosis, and age > 40 years. These factors in addition to adequacy of surgical reduction allow us to better counsel patients as to long-term prognosis.

Acetabulum↗
PubMed1997

Changes in airway space following mandibular setback using sagittal split osteotomy and rigid internal fixation.

The changes in airway space following mandibular setback using sagittal split osteotomy and rigid internal fixation were studied in 28 Japanese patients with mandibular prognathism. The correlation between the amount of mandibular setback and airway space changes, as well as the correlation between the amount of airway space changes and relapse of pognion point during the following-up period were also studied. Lateral cephalometric radiographs were taken immediately before and shortly after surgery as well as 5 to 12 months postoperation. The cephalometric evaluations of airway space width and area were based on stable craniofacial landmarks. The mean setback of mandible was 8.3 mm in the right side, and 8.2 mm in the left side. The mean amount of relapse of pogonion point during the following-up period was 0.52 mm horizontally, and 0.92 mm vertically. A significant decrease in airway space width and area, especially in the lower part of airway space was found following mandibular setback shortly after surgery. Although there was some increase both in airway space width and area during the following-up period, they did not increase to their original values. This suggests that the narrowing of airway space following mandibular setback using sagittal split osteotomy can be permanent. No significant correlation was found between the amount of mandibular setback and airway space changes. Since the relapse of pogonion point during the following-up period was too small, there is no significant correlation between it and the amount of airway space changes.

Adolescent↗
PubMed2005

Long-term outcome in 132 consecutive patients after posterior internal fixation and fusion for Grade I and II isthmic spondylolisthesis.

OBJECT: The authors assessed the late outcome of patients with Meyerding Grade I and II isthmic spondylolisthesis (IS) who underwent posterior instrumentation and posterolateral fusion (PLF). Decompression and posterior internal fixation with PLF is the classic surgical treatment for painful low-grade IS. Nevertheless, outcome data are scarce and of limited value mainly because they represent small numbers of patients, short follow-up periods, or both. METHODS: The authors obtained data in the cases of 132 consecutive adult patients (mean age 40.6 years, range 15.2-69.9 years) with IS who underwent treatment between 1984 and 2003. Assessment involved analysis of responses to mailed questionnaires, clinical charts and, in cases in which unsatisfactory results were suspected, results of clinical reevaluations. Spondylolisthesis was present at L3-4 in three patients, L4-5 in 14, L3-4 in one, L3-5 in one, L5-S1 in 113, and S1-2 in one. Signs and symptoms included back and leg pain (65.3%), leg pain alone (26.3%), back pain alone (8.4%), and neurological dysfunction (18%). At a mean follow-up duration of 9.9 years (range 0.5-19.4 years), favorable results were reported for back and leg pain in 91.7 and 87.1% of patients, respectively. The mean visual analog scale scores were 2.13 for back and 1.59 for leg pain. Eighty-four patients resumed full- or part-time work, and 56.8% were capable of performing housework more easily. In 45.5% of the patients analgesic medications were not required, and 43.9% required them sporadically. The majority (63.6%) of patients reported they would undergo surgery again and recommended it to others. Thirteen (9.9%) suffered adjacent-segment morbidity, and in seven (5.3%) pseudarthrosis was documented. There were two deep and one superficial infections (2.3%). CONCLUSIONS: Posterior instrumentation and PLF, with possible neurodecompression, yielded favorable long-term results in this retrospective study of 132 patients with low-grade IS.

Adolescent↗