scholarly journals Use of External Fixators as a 3-Dimensional Navigation Drill Guide for Arthroscopic Ankle Arthrodesis

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Young Uk Park ◽  
Hyong Nyun Kim
Keyword(s):  
Prior Experience ◽  
Ankle Arthrodesis ◽  
External Fixators ◽  
Cannulated Screws ◽  
Bone Model ◽  
Screw Insertion ◽  
3 Dimensional ◽  
Novel Technique ◽  
Drill Guide ◽  
Percutaneous Screws

In this article, we describe a novel technique using external fixators and cannulated screws to construct a 3-dimensional navigation drill guide to predict the screw trajectory before screw insertion that can prevent screw collision during arthroscopic ankle arthrodesis. Four orthopedic residents who had no prior experience of ankle arthrodesis were instructed on how to use the 3-dimensional navigation drill guide and where to insert the screws for ankle arthrodesis. Each resident inserted 6.5 cannulated screws on 8 sawbone ankle models using the device and the C-arm fluoroscopy. An experienced attending surgeon also inserted the same screws on 2 sawbone ankle models to find out if there is any difference between the experienced and inexperienced surgeons. All four residents and an attending surgeon did not experience any collision of screws for the three cannulated screws. Notably, one resident had collision of the 4th screw on his first sawbone model. On the second saw bone model, all surgeons could insert 5 screws without redrilling. A 3-dimensional navigation drill guide constructed with external fixators can assist surgeons in implementing percutaneous screws for arthroscopic ankle arthrodesis.

Transfacet screw placement for posterior fixation of C-7

2008 ◽  
Vol 9 (2) ◽  
pp. 200-206 ◽  
Author(s):  
Eric M. Horn ◽  
Nicholas Theodore ◽  
Neil R. Crawford ◽  
Nicholas C. Bambakidis ◽  
Volker K. H. Sonntag
Keyword(s):  
Intraoperative Complications ◽  
Pedicle Screws ◽  
Retrospective Chart Review ◽  
Screw Placement ◽  
Posterior Fixation ◽  
Lateral Mass ◽  
Screw Insertion ◽  
Novel Technique ◽  
Hardware Failures

Object Lateral mass screws are traditionally used to fixate the subaxial cervical spine, while pedicle screws are used in the thoracic spine. Lateral mass fixation at C-7 is challenging due to thin facets, and placing pedicle screws is difficult due to the narrow pedicles. The authors describe their clinical experience with a novel technique for transfacet screw placement for fixation at C-7. Methods A retrospective chart review was undertaken in all patients who underwent transfacet screw placement at C-7. The technique of screw insertion was the same for each patient. Polyaxial screws between 8- and 10-mm-long were used in each case and placed through the facet from a perpendicular orientation. Postoperative radiography and clinical follow-up were analyzed for aberrant screw placement or construct failure. Results Ten patients underwent C-7 transfacet screw placement between June 2006 and March 2007. In all but 1 patient screws were placed bilaterally, and the construct lengths ranged from C-3 to T-5. One patient with a unilateral screw had a prior facet fracture that precluded bilateral screw placement. There were no intraoperative complications or screw failures in these patients. After an average of 6 months of follow-up there were no hardware failures, and all patients showed excellent alignment. Conclusions The authors present the first clinical demonstration of a novel technique of posterior transfacet screw placement at C-7. These results provide evidence that this technique is safe to perform and adds stability to cervicothoracic fixation.

Finite element analysis of the impact of screw insertion distal to the trochanter minor on the risk of iatrogenic subtrochanteric fracture

2018 ◽  
Vol 232 (8) ◽  
pp. 807-818 ◽  
Author(s):  
Ersin Sensoz ◽  
Fatih Mehmet Özkal ◽  
Volkan Acar ◽  
Ferit Cakir
Keyword(s):  
Finite Element ◽  
Femoral Neck ◽  
Screw Fixation ◽  
Subtrochanteric Fracture ◽  
Femoral Neck Fractures ◽  
Cannulated Screws ◽  
Screw Insertion ◽  
Subtrochanteric Fractures ◽  
Trochanter Minor ◽  
The Impact

Iatrogenic subtrochanteric fractures are rarely encountered after cannulated screw fixation of femoral neck fractures; however, when they do occur, there can be several complications. Many orthopedic surgeons have concerns about the potential for iatrogenic subtrochanteric fractures after screw fixation distal to the trochanter minor; therefore, some surgeons are typically reluctant to perform this procedure. This study focused on the risk of an iatrogenic subtrochanteric fracture after treating femoral neck fractures with cannulated screws. The main purpose of the study was to understand iatrogenic subtrochanteric fractures and evaluate the effects on these fractures of an inverted triangular–shaped configuration for placement of the cannulated screws. A femur bone with an femoral neck fracture at a 40° incline to the horizontal plane was generated along with a representation of a three-dimensional finite element model, and three inverted triangular–shaped configurations for placement of the cannulated screws were investigated using finite element analyses. Statistical results indicated that the occurrence risk of ISF increases when the screw is located distal to the trochanter minor. Moreover, the risk of occurrence of intertrochanteric fracture increases when the screw is located medial to the trochanter minor because of local concentrated stress on the surface of the screw canals. To avoid the vulnerability of the subtrochanteric region, it was found that proximal placement of the screws using the inverted triangular–shaped configuration could yield better results. In addition, the results of this study provide suggestions on improved screw configurations.

scholarly journals Safe Zone of Posterior Screw Insertion for Talar Neck Fractures on 3-Dimensional Reconstruction Model

2017 ◽  
Vol 9 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Jian-qun Wu ◽  
Sheng-hui Ma ◽  
Song Liu ◽  
Cheng-he Qin ◽  
Dan Jin ◽  
...  
Keyword(s):  
Safe Zone ◽  
Screw Insertion ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Reconstruction Model ◽  
Talar Neck Fractures

scholarly journals Combined tibial lengthening and ankle arthrodesis for patients with certain type of sequelae of poliomyelitis

2017 ◽  
Vol 25 (1) ◽  
pp. 230949901668441
Author(s):  
Chi-Chuan Wu
Keyword(s):  
Bone Graft ◽  
Functional Disability ◽  
Muscle Power ◽  
Ankle Arthrodesis ◽  
Bone Graft Substitute ◽  
Modern Medicine ◽  
External Fixators ◽  
Lesion Side ◽  
Gait Function

Purpose: Following far advancement of modern medicine and technology, functional disability in a certain type of sequelae of poliomyelitis may be effectively improved. Methods: Eight consecutive adult patients with unilateral sequelae of poliomyelitis were treated. These patients had shortened lower extremity of an average of 4.8 cm (range, 4.0–5.5 cm) in the lesion side. Muscle power of the ipsilateral knee was nearly intact (grade 4 or 5) but the ankle extension was completely flaccid. The tibia was osteotomized and lengthened with external fixation. Consequently, all external fixators were converted to plates supplemented with autogenous corticocancellous bone graft and bone graft substitute. Ankle arthrodesis was performed concomitantly. Results: Seven patients were followed up for an average of 3.7 years (range, 2.2–5.4 years). All seven lengthened sites healed with an average union time of 3.9 months (range, 3.5–4.5 months) after plating. One ankle infection occurred. Gait function significantly improved by modified Mazur scoring evaluation ( p = 0.02). At the latest follow-up, all patients had a minimal or unnoticed limp in level walking. Conclusion: The described combined techniques may be an excellent alternate for treating selected patients with sequelae of poliomyelitis. The procedure is not complex but the efficiency is extremely prominent.

Effects of Gender on Perception of Spatial Illusions

1995 ◽  
Vol 80 (2) ◽  
pp. 625-626 ◽  
Author(s):  
Marc E. Pratarelli ◽  
Brenda J. Steitz
Keyword(s):  
Prior Experience ◽  
Spatial Skills ◽  
3 Dimensional ◽  
Visual Spatial ◽  
Performance Differences ◽  
Males And Females

Popular theories explaining performance differences between males and females generally predict that females tend to outperform males on certain perceptual and linguistic tasks, while males outperform females on tasks involving visual-spatial skills. 28 males and females were shown commercially available computer-generated 3-dimensional illusions in which the hidden object(s) varied in complexity. Although females reported more prior experience with this form of art, males were about four times faster at identifying the illusions at all levels of difficulty.

Sign in / Sign up

Export Citation Format

Share Document