57. Biomechanical Importance of S1 and Iliac Fixation when Instrumenting to the Pelvis: Analysis of Four Modern Lumbosacral Fixation Techniques

Tracheary elements, the water-conducting cells in plants, are characterized by their reinforced walls that became thickened in localized patterns during differentiation (Fig. 1). The synthesis of this localized wall involves abundant secretion of Golgi vesicles that export preformed matrix polysaccharides and putative proteins involved in cellulose synthesis. Since the cells are not growing, some kind of endocytotic process must also occur. Many researchers have commented on where exocytosis occurs in relation to the thickenings (for example, see), but they based their interpretations on chemical fixation techniques that are not likely to provide reliable information about rapid processes such as vesicle fusion. We have used rapid freezing to more accurately assess patterns of vesicle fusion in tracheary elements. We have also determined the localization of calcium, which is known to regulate vesicle fusion in plant and animal cells.Mesophyll cells were obtained from immature first leaves of Zinnia elegans var. Envy (Park Seed Co., Greenwood, S.C.) and cultured as described previously with the following exceptions: (a) concentration of benzylaminopurine in the culture medium was reduced to 0.2 mg/l and myoinositol was eliminated; and (b) 1.75ml cultures were incubated in 22 x 90mm shell vials with 112rpm rotary shaking. Cells that were actively involved in differentiation were harvested and frozen in solidifying Freon as described previously. Fractures occurred preferentially at the cell/planchet interface, which allowed us to find some excellently-preserved cells in the replicas. Other differentiating cells were incubated for 20-30 min in 10(μM CTC (Sigma), an antibiotic that fluoresces in the presence of membrane-sequestered calcium. They were observed in an Olympus BH-2 microscope equipped for epi-fluorescence (violet filter package and additional Zeiss KP560 barrier filter to block chlorophyll autofluorescence).

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Open reduction of pediatric lateral condyle fractures: a systematic review

Shoulder & Elbow ◽

10.1177/17585732211010299 ◽

2021 ◽

pp. 175857322110102

Author(s):

Michael D Eckhoff ◽

Josh C Tadlock ◽

Tyler C Nicholson ◽

Matthew E Wells ◽

EStephan J Garcia ◽

...

Keyword(s):

Systematic Review ◽

Internal Fixation ◽

Range Of Motion ◽

Lateral Condyle ◽

Elbow Fracture ◽

Infection Rates ◽

Fixation Techniques ◽

K Wires ◽

Pediatric Elbow Fracture ◽

The Cost

Introduction Lateral condyle fractures are the second most common pediatric elbow fracture. There exist multiple options for internal fixation including buried K-wires, unburied K-wires, and screw fixation. Our study aims to review the current literature and determine if fixation strategy affects outcomes to include fracture union, postoperative range of motion, and need subsequent surgery. Methods A systematic review of Pubmed, MEDLINE, and EMBASE databases was performed. Included articles involve pediatric patients with displaced lateral condyle fractures treated with internal fixation that reported outcomes to include union rates and complications. Results Thirteen studies met inclusion criteria for a total of 1299 patients (472 buried K-wires, 717 unburied K-wires, and 110 screws). The patients’ average age was 5.8 ± 0.6 years, male (64%), and had 16.3 months of follow-up. No differences in union and infection rates were found. Unburied K-wires had the shortest time to union and the greatest elbow range of motion postoperatively. Conclusions Our systematic review demonstrates similar outcomes with union and infection rates between all fixation techniques. Unburied K-wires demonstrated a shorter time to union and the greatest postoperative range of motion. Additionally, unburied K-wires may be removed in clinic, decreasing the cost on the healthcare system. Evidence Level 3.

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Clinical outcomes of acute displaced posterior cruciate ligament tibial avulsion fracture: A retrospective comparative study between the arthroscopic suture and EndoButton fixation techniques

Orthopaedics & Traumatology Surgery & Research ◽

10.1016/j.otsr.2020.102798 ◽

2020 ◽

pp. 102798

Author(s):

Daohong Zhao ◽

Jia Zhong ◽

Bo Zhao ◽

Yan Li ◽

Duo Shen ◽

...

Keyword(s):

Comparative Study ◽

Posterior Cruciate Ligament ◽

Clinical Outcomes ◽

Avulsion Fracture ◽

Cruciate Ligament ◽

Tibial Avulsion Fracture ◽

Fixation Techniques ◽

Retrospective Comparative Study

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Biomechanical Assessment of Anterior Lumbar Interbody Fusion With an Anterior Lumbosacral Fixation Screw-Plate: Comparison to Stand-Alone Anterior Lumbar Interbody Fusion and Anterior Lumbar Interbody Fusion With Pedicle Screws in an Unstable Human Cadaver Model

Spine ◽

10.1097/01.brs.0000206360.83728.d2 ◽

2006 ◽

Vol 31 (7) ◽

pp. 762-768 ◽

Cited By ~ 63

Author(s):

Mark Gerber ◽

Neil R. Crawford ◽

Robert H. Chamberlain ◽

Mary S. Fifield ◽

Jean-Charles LeHuec ◽

...

Keyword(s):

Interbody Fusion ◽

Pedicle Screws ◽

Anterior Lumbar Interbody Fusion ◽

Lumbar Interbody Fusion ◽

Human Cadaver ◽

Biomechanical Assessment ◽

Fixation Screw ◽

Lumbosacral Fixation ◽

Human Cadaver Model

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Biomechanical characteristics of C1–2 cable fixations

Journal of Neurosurgery ◽

10.3171/jns.1996.85.2.0316 ◽

1996 ◽

Vol 85 (2) ◽

pp. 316-322 ◽

Cited By ~ 106

Author(s):

Curtis A. Dickman ◽

Neil R. Crawford ◽

Christopher G. Paramore

Keyword(s):

Cyclic Loading ◽

Translational Motion ◽

Biomechanical Testing ◽

Three Dimensional ◽

Constrained Motion ◽

Content Type ◽

Physiological Range ◽

Fixation Techniques ◽

Cable Fixation ◽

Fine Print

✓ The biomechanical characteristics of four different methods of C1–2 cable fixation were studied to assess the effectiveness of each technique in restoring atlantoaxial stability. Biomechanical testing was performed on the upper cervical spines of four human cadaveric specimens. Physiological range loading was applied to the atlantoaxial specimens and three-dimensional motion was analyzed with stereophotogrammetry. The load–deformation relationships and kinematics were measured, including the stiffness, the angular ranges of motion, the linear ranges of motion, and the axes of rotation. Specimens were nondestructively tested in the intact state, after surgical destabilization, and after each of four different methods of cable fixation. Cable fixation techniques included the interspinous technique, the Brooks technique, and two variants of the Gallie technique. All specimens were tested immediately after fixation and again after the specimen was fatigued with 6000 cycles of physiological range torsional loading. All four cable fixation methods were moderately flexible immediately; the different cable fixations allowed between 5° and 40° of rotational motion and between 0.6 and 7 mm of translational motion to occur at C1–2. The Brooks and interspinous methods controlled C1–2 motion significantly better than both of the Gallie techniques. The motion allowed by one of the Gallie techniques did not differ significantly from the motion of the unfixed destabilized specimens. All cable fixation techniques loosened after cyclic loading and demonstrated significant increases in C1–2 rotational and translational motions. The bone grafts shifted during cyclic loading, which reduced the effectiveness of the fixation. The locations of the axes of rotation, which were unconstrained and mobile in the destabilized specimens, became altered with cable fixation. The C1–2 cables constrained motion by shifting the axes of rotation so that C-1 rotated around the fixed cable and graft site. After the specimen was fatigued, the axes of rotation became more widely dispersed but were usually still localized near the cable and graft site. Adequate healing requires satisfactory control of C1–2 motion. Therefore, some adjunctive fixation is advocated to supplement the control of motion after C1–2 cable fixation (that is, a cervical collar, a halo brace, or rigid internal fixation with transarticular screws).

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