The effect of screw trajectory for the reduction and association of the scaphoid and lunate (RASL) procedure: a biomechanical analysis

2017 ◽  
Vol 43 (6) ◽  
pp. 635-641 ◽  
Author(s):  
Steven M. Koehler ◽  
Christina M. Beck ◽  
Philip Nasser ◽  
Matthew Gluck ◽  
Michael R. Hausman
Keyword(s):  
Euler Angle ◽  
Biomechanical Analysis ◽  
Screw Placement ◽  
Scapholunate Ligament ◽  
Lateral Aspect ◽  
Time Motion ◽  
Volar Aspect ◽  
Starting Point ◽  
Dorsal Ridge ◽  
Fresh Frozen

The purpose of this study was to determine if screw placement in the reduction and association of the scaphoid and the lunate (RASL) procedure affected the ability of the scapholunate joint to withstand force. After completely disrupting of the scapholunate ligament in 29 fresh-frozen cadaveric wrists, we placed the RASL screw either distal or proximal to the lateral aspect of the dorsal ridge of the scaphoid and into the dorsal or volar aspect of the lunate. Specimens were subjected to repeated cycles of transcarpal axial force, mimicking clenched-fist loading, until failure. Screw placement distal to the lateral aspect of the dorsal scaphoid ridge was significantly associated with failure when examined manually, radiographically (1.8 vs. 0.5 mm) and using real-time motion capture (diastasis: 1.6 vs. 0.4 mm; Euler angle: 4.5 ° vs. 0.8 °). The lateral aspect of the dorsal ridge is a reliable radiographic landmark on the scaphoid and provides surgeons with a convenient starting point to achieve the most biomechanically stable RASL construct, and, therefore, enhances the potential for an optimal clinical outcome.

Factors affecting lateral mass screw placement at C-7

2011 ◽  
Vol 14 (3) ◽  
pp. 405-411 ◽  
Author(s):  
Kalil G. Abdullah ◽  
Amy S. Nowacki ◽  
Michael P. Steinmetz ◽  
Jeffrey C. Wang ◽  
Thomas E. Mroz
Keyword(s):  
Sagittal Plane ◽  
Anatomical Variation ◽  
Axial Plane ◽  
Screw Placement ◽  
Lateral Mass ◽  
Lateral Mass Screw ◽  
Modified Technique ◽  
Modified Method ◽  
Starting Point ◽  
Lateral Mass Screws

Object The C-7 lateral mass has been considered difficult to fit with instrumentation because of its unique anatomy. Of the methods that exist for placing lateral mass screws, none particularly accommodates this anatomical variation. The authors have related 12 distinct morphological measures of the C-7 lateral mass to the ability to place a lateral mass screw using the Magerl, Roy-Camille, and a modified Roy-Camille method. Methods Using CT scans, the authors performed virtual screw placement of lateral mass screws at the C-7 level in 25 male and 25 female patients. Complications recorded included foraminal and articular process violations, inability to achieve bony purchase, and inability to place a screw longer than 6 mm. Violations were monitored in the coronal, axial, and sagittal planes. The Roy-Camille technique was applied starting directly in the middle of the lateral mass, as defined by Pait's quadrants, with an axial angle of 15° lateral and a sagittal angle of 90°. The Magerl technique was performed by starting in the inferior portion of the top right square of Pait's quadrants and angling 25° laterally in the axial plane with a 45° cephalad angle in the sagittal plane. In a modified method, the starting point is similar to the Magerl technique in the top right square of Pait's quadrant and then angling 15° laterally in the axial plane. In the sagittal plane, a 90° angle is taken perpendicular to the dorsal portion of the lateral mass, as in the traditional Roy-Camille technique. Results Of all the morphological methods analyzed, only a combined measure of intrusion of the T-1 facet and the overall length of the C-7 lateral mass was statistically associated with screw placement, and only in the Roy-Camille technique. Use of the Magerl technique allowed screw placement in 28 patients; use of the Roy-Camille technique allowed placement in 24 patients; and use of the modified technique allowed placement in 46 patients. No screw placement by any method was possible in 4 patients. Conclusions There is only one distinct anatomical ratio that was shown to affect lateral mass screw placement at C-7. This ratio incorporates the overall length of the lateral mass and the amount of space occupied by the T-1 facet at C-7. Based on this virtual study, a modified Roy-Camille technique that utilizes a higher starting point may decrease the complication rate at C-7 by avoiding placement of the lateral mass screw into the T1 facet.

scholarly journals Tuber-to-Anterior Process Angle (TAPA): A Cadaveric Study and Surgical Technique for Placing Axial Calcaneal Screws

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0041
Author(s):  
Kristen L. Stupay ◽  
Jorge Briceno ◽  
Brian Velasco ◽  
John Y. Kwon
Keyword(s):  
Surgical Technique ◽  
Guide Wire ◽  
Articular Surface ◽  
Plate Fixation ◽  
Operative Management ◽  
Screw Placement ◽  
Anterior Process ◽  
Starting Point ◽  
K Wires ◽  
Average Angle

Category: Ankle, Hindfoot Introduction/Purpose: Operative management of displaced intra-articular calcaneus fractures frequently involves placement of P: A screws in order to maintain calcaneal length and axial alignment. While plate fixation may still be more commonly utilized, screw-only fixation for the treatment of these fractures has been demonstrated by several authors to be safe and effective. Directing fixation from the tuber into the anterior process can be challenging. Understanding the calcaneal long-axis as it relates to the long-axis of the foot, a measurement we call the Tuber-to-Anterior Process Angle (TAPA), can facilitate the ease and accuracy of guide-wire and cannulated screw placement. The goals of this study are to define the TAPA, and to report a surgical technique which uses this angle to facilitate axial screw placement. Methods: Eight cadaver feet were utilized. A longitudinal pin was placed from the center of the posterior calcaneal tuber to the 2nd metatarsal heads. Next, the calcaneocuboid joint was exposed, and a wedge of cuboid was removed. A calcaneal pin was then placed, exiting at the center of the anterior process. The tips of two small K-wires were impacted into the medial and lateral-most aspects of the articular surface. A true axial view of each specimen was obtained. On these images, a digital line was drawn from the posterior tuber starting point and the central calcaneal pin, representing the calcaneal long-axis. The angle subtended by this line and the long-axis of the foot represents the TAPA. Digital lines were drawn between the posterior tuber starting point and the medial and lateral K-wires, and the range between their subtending angles represents the axial plane tolerance for screw placement within the anterior process. Results: The average TAPA measured 10.9 ± 1.3 degrees (range: 8.4-13.0). The average angle, as measured to the medial extent of the anterior calcaneus, measured 2.8 ± 1.3 degrees (range: 0.4-4.3). The average angle, as measured to the lateral extent of the anterior calcaneus, measured 19.0 ± 2.7 degrees (range: 15.7-22.7). Conclusion: Knowledge of the Tuber-to-Anterior Process Angle (TAPA), found to be 10.9 degrees (± 1.8 degrees) laterally deviated from the long-axis of the foot, simplifies placement of posterior-to-anterior screws in the calcaneus. Understanding this relationship reduces reliance on intraoperative axial fluoroscopy and increases operative efficiency. Furthermore, this knowledge can be applied during other procedures in which axial screw placement is performed, such as with corrective calcaneal osteotomy.

scholarly journals Time-motion analysis of competitive surfers: Portuguese championship

2019 ◽  
Vol 65 (6) ◽  
pp. 810-817
Author(s):  
Beatriz Minghelli ◽  
Sara Paulino ◽  
Sara Graça ◽  
Inês Sousa ◽  
Priscilla Minghelli
Keyword(s):  
Motion Analysis ◽  
Training Programs ◽  
Analysis Software ◽  
Activity Profile ◽  
Time Motion ◽  
Starting Point ◽  
Time Average ◽  
Insight Into ◽  
Stationary Period ◽  
Activity Times

SUMMARY BACKGROUND: Time-motion analysis has been used to provide detailed insight into surfers’ performance. This study evaluated surfers’ activity times at the Portuguese surfing championship in order to account for the time spent in each surfing activity. METHODS: Eighty-seven individually recorded videos of surfers were analyzed, showing their activity over the entire heat, and video analysis software was used to obtain each surfer's activity profile in the competition. RESULTS: The results breakdown by time percentage show that the surfers were paddling 50.9% of the time, sprint paddling for wave 1.9%, were stationary 34.1% of the time, wave riding 3.7%, and involved in miscellaneous activities (e.g., duck diving, board recovery, etc.) 9.4% of the total time. Average times spent in each surfing activity were 18.6 seconds for paddling, 2.9 seconds for sprint paddling for a wave, 21.7 seconds for the stationary period, 11.5 seconds for wave riding, and 6.9 seconds for miscellaneous activities. CONCLUSIONS: The data revealed that the most performed heat activity was paddling, allowing us to conclude that surfing is basically a long-arm paddling activity and that this activity constitutes a specific surfing competition demand, which in turn means that individual surfer's data can be used as a starting point for the development of tailored conditioning training programs.

A Biomechanical Comparative Analysis of Two Techniques for Tibiotalar Arthrodesis

1994 ◽  
Vol 15 (6) ◽  
pp. 301-305 ◽  
Author(s):  
Robert L. Friedman ◽  
Richard R. Glisson ◽  
James A. Nunley
Keyword(s):  
Laboratory Testing ◽  
Biomechanical Analysis ◽  
Torsional Motion ◽  
Bending Tests ◽  
Torsional Testing ◽  
Fusion Site ◽  
Fresh Frozen ◽  
Tibiotalar Arthrodesis ◽  
Cancellous Screws ◽  
Cantilever Bending

Two commonly used techniques for tibiotalar fusion were quantitatively compared using instrumented testing of the strength of the construct. The tibiae and tali from 10 pairs of fresh-frozen cadaveric limbs were used. One joint of each pair was fused using two 6.5-mm crossed cancellous screws from proximal to distal while the contralateral joint was fused using two 6.5-mm parallel cancellous screws from distal to proximal. Each specimen was subjected to cantilever bending and torsional testing by servohydraulic actuators. The bending tests included plantarflexion, dorsiflexion, inversion, and eversion, and measured the load during deflection applied 10 cm distal to the fusion site. The rigidity was expressed as newtons per millimeter of deflection. The torsional tests measured construct stiffness in external and internal rotation, and were expressed as newton-meters per degree of rotation. For the bending tests, the crossed screw construct was more rigid in eversion (23.1 N/mm, P = .0004) and dorsiflexion (16.9 N/mm, P = .02), while the parallel screw construct was more rigid in inversion (22.8 N/mm, P = .02) and plantarflexion (22.3 N/mm, P = .0007). In torsional testing, the crossed screw construct was at least 1.5 times stiffer than the parallel screw construct in resisting internal (1.7 N-m/deg versus 0.9 N-m/deg, P = .0001) and external (1.4 N-m/deg versus 0.9 N-m/deg, P = .02) rotation. In laboratory testing, the crossed screw technique is more rigid than the parallel screws, especially in resisting torsional stresses. Assuming that a stronger construct is desirable, and given that short leg casts commonly used after such fusions do not completely restrict torsional motion, this biomechanical analysis suggests that the crossed screw technique improves the likelihood of a successful arthrodesis.

scholarly journals Hip Capsular Closure: A Biomechanical Analysis of Failure Torque

2016 ◽  
Vol 45 (2) ◽  
pp. 434-439 ◽  
Author(s):  
Jorge Chahla ◽  
Jacob D. Mikula ◽  
Jason M. Schon ◽  
Chase S. Dean ◽  
Kimi D. Dahl ◽  
...  
Keyword(s):  
External Rotation ◽  
Arthroscopic Surgery ◽  
Testing Machine ◽  
Biomechanical Analysis ◽  
Biaxial Testing ◽  
Improved Outcomes ◽  
Significant Difference ◽  
Fresh Frozen ◽  
Hip Capsule ◽  
Optimal Quantity

Background: Hip capsulotomy is routinely performed during arthroscopic surgery to achieve adequate exposure of the joint. Iatrogenic instability can result after hip arthroscopic surgery because of capsular insufficiency, which can be avoided with effective closure of the hip capsule. There is currently no consensus in the literature regarding the optimal quantity of sutures upon capsular closure to achieve maximal stability postoperatively. Purpose/Hypothesis: The purpose of this study was to determine the failure torques of 1-, 2-, and 3-suture constructs for hip capsular closure to resist external rotation and extension after standard anterosuperior interportal capsulotomy (12 to 3 o’clock). Additionally, the degree of external rotation at which the suture constructs failed was recorded. The null hypothesis of this study was that no significant differences with respect to the failure torque would be found between the 3 repair constructs. Study Design: Controlled laboratory study. Methods: Nine pairs (n = 18) of fresh-frozen human cadaveric hemipelvises underwent anterosuperior interportal capsulotomy, which were repaired with 1, 2, or 3 side-to-side sutures. Each hip was secured in a dynamic biaxial testing machine and underwent a cyclic external rotation preconditioning protocol, followed by external rotation to failure. Results: The failure torque of the 1-suture hip capsular closure construct was significantly less than that of the 3-suture construct. The median failure torque for the 1-suture construct was 67.4 N·m (range, 47.4-73.6 N·m). The median failure torque was 85.7 N·m (range, 56.9-99.1 N·m) for the 2-suture construct and 91.7 N·m (range, 74.7-99.0 N·m) for the 3-suture construct. All 3 repair constructs exhibited a median 36° (range, 22°-64°) of external rotation at the failure torque. Conclusion: The most important finding of this study was that the 2- and 3-suture constructs resulted in comparable biomechanical failure torques when external rotation forces were applied to conventional hip capsulotomy in a cadaveric model. The 3-suture construct was significantly stronger than the 1-suture construct; however, there was not a significant difference between the 2- and 3-suture constructs. Additionally, all constructs failed at approximately 36° of external rotation. Clinical Relevance: Re-establishing the native anatomy of the hip capsule after hip arthroscopic surgery has been reported to result in improved outcomes and reduce the risk of iatrogenic instability. Therefore, adequate capsular closure is important to restore proper hip biomechanics, and postoperative precautions limiting external rotation should be utilized to protect the repair.

scholarly journals Biomechanical Analysis of Articulating Intercarpal Screw Fixation After Scapholunate Ligament Division

2015 ◽  
Vol 40 (9) ◽  
pp. e32-e33
Author(s):  
Matthew E. Hiro ◽  
Muturi Muriuki ◽  
Corey J. Schiffman ◽  
Robert M. Havey ◽  
Leonard Voronov ◽  
...  
Keyword(s):  
Screw Fixation ◽  
Biomechanical Analysis ◽  
Scapholunate Ligament

Syndesmotic Screw Placement: A Biomechanical Analysis

1997 ◽  
Vol 18 (5) ◽  
pp. 262-266 ◽  
Author(s):  
Angus McBryde ◽  
Brett Chiasson ◽  
Andrew Wilhelm ◽  
Frank Donovan ◽  
Tamara Ray ◽  
...  
Keyword(s):  
Proximal Tibia ◽  
Screw Fixation ◽  
T Test ◽  
Biomechanical Analysis ◽  
Screw Placement ◽  
Tibiotalar Joint ◽  
Maisonneuve Fracture ◽  
Syndesmotic Screw ◽  
Group I ◽  
The Right

At the present time, syndesmotic screw fixation is recommended when there is a tibiofibular diastasis, a Maisonneuve fracture, or syndesmotic instability after fixation of distal tibia-fibula fractures. The aim/purpose of this study was to demonstrate the optimal level of syndesmotic screw placement before creation of a Maisonneuve fracture. Legs of 17 embalmed cadavers underwent knee disarticulation. The legs were then dissected to expose the syndesmosis/interosseous membrane. The paired cadaver legs were tested in two groups. In group I (10 pairs), the left legs were tested without any syndesmotic fixation and the right legs were tested with the syndesmosis fixed at 2.0 cm above the tibiotalar joint. In group II (7 pairs), the syndesmosis in each left leg was fixed at 3.5 cm above the tibiotalar joint and the right leg syndesmosis was fixed at 2.0 cm above the tibiotalar joint. After ligament section and syndesmosis fixation, each leg was then jig mounted with transfixing wires through the proximal tibia and calcaneus. The ankle was placed in neutral with 15° of pronation and a load of 150 pounds and a strain gauge anchored medially and laterally. The proximal tibia was internally rotated while the ankle was held fixed until syndesmotic, bony, or hardware failure occurred. Torsional force, the degree of rotation and the amount of syndesmotic widening were quantitated. Two-tailed t-test comparing no fixation with fixation at 2.0 cm indicated less syndesmotic widening with screw placed at 2.0 cm ( P = 0.04). Two-tailed t-test comparing screw fixation at 2.0 cm and 3.5 cm indicated less syndesmotic widening with screw placed at 2.0 cm ( P = 0.07). It would seem reasonable to place a syndesmotic screw at 2.0 cm above tibiotalar joint.

scholarly journals The Anatomy of the Dorsal Capsulo-Scapholunate Septum: A Cadaveric Study

2017 ◽  
Vol 06 (03) ◽  
pp. 244-247 ◽  
Author(s):  
Marina Tommasini Carrara de Sambuy ◽  
Tanya Burgess ◽  
Christophe Mathoulin ◽  
Adeline Cambon-Binder
Keyword(s):  
Dorsal Surface ◽  
Anatomical Study ◽  
Biomechanical Properties ◽  
Scapholunate Ligament ◽  
Maximum Width ◽  
Interosseous Ligament ◽  
Gothic Architecture ◽  
Constant Structure ◽  
Fresh Frozen ◽  
The Mean

Background Tears of the dorsal radiocarpal capsule at the level of the scapholunate interosseous ligament (SLIL) have recently been described in association with predynamic scapholunate instability. Purpose The aim of this anatomical study of the dorsal capsulo-scapholunate septum (DCSS) was to examine the connection of the dorsal capsule on the SLIL and dorsal intercarpal ligament (DICL). Methods Fourteen fresh frozen wrists from seven adult cadavers were dissected through a dorsal approach. Any dorsal attachment of the DICL on the dorsal surface of the SLIL, that is, the DCSS, was identified and measured (height and width). Results The DCSS was consistently found connecting the DICL, the dorsal radiocarpal capsule, and the dorsal aspect of the SLIL. It was formed by the confluence of three arches like intersecting ribs in gothic architecture. The mean dimensions of the DCSS were 5.8 mm in height and 4.0 mm in maximum width. Conclusion The DCSS that connects the SLIL with the dorsal capsule and DICL could be a constant structure of dorsal wrist. Further investigation is required to study the histology of the DCSS and its biomechanical properties in isolation to know whether the DCSS can be considered a secondary stabilizer of the scapholunate ligament complex. Clinical Relevance A better anatomical knowledge of scapholunate ligament complex could help understand and manage instability of the wrist.

scholarly journals A quantitative, biomechanical analysis of radioulnar deviation between fresh frozen and soft embalmed human forearms

2013 ◽  
Vol 27 (S1) ◽  
Author(s):  
Craig Bradley Casier ◽  
Ron Easteal ◽  
Rick Sellens ◽  
Andrew Dickinson ◽  
Jessica Clark
Keyword(s):  
Biomechanical Analysis ◽  
Fresh Frozen

Simulated Lumbar Minimally Invasive Surgery Educational Model With Didactic and Technical Components

Neurosurgery ◽  
2013 ◽  
Vol 73 (suppl_1) ◽  
pp. S107-S110
Author(s):  
Rohan Chitale ◽  
George M. Ghobrial ◽  
Darlene Lobel ◽  
James Harrop
Keyword(s):  
Minimally Invasive ◽  
Pedicle Screw ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
Educational Curriculum ◽  
Computed Tomographic ◽  
Percutaneous Pedicle Screw ◽  
Starting Point ◽  
Objectively Measured ◽  
Invasive Techniques

Abstract BACKGROUND: The learning and development of technical skills are paramount for neurosurgical trainees. External influences and a need for maximizing efficiency and proficiency have encouraged advancements in simulator-based learning models. OBJECTIVE: To confirm the importance of establishing an educational curriculum for teaching minimally invasive techniques of pedicle screw placement using a computer-enhanced physical model of percutaneous pedicle screw placement with simultaneous didactic and technical components. METHODS: A 2-hour educational curriculum was created to educate neurosurgical residents on anatomy, pathophysiology, and technical aspects associated with image-guided pedicle screw placement. Predidactic and postdidactic practical and written scores were analyzed and compared. Scores were calculated for each participant on the basis of the optimal pedicle screw starting point and trajectory for both fluoroscopy and computed tomographic navigation. RESULTS: Eight trainees participated in this module. Average mean scores on the written didactic test improved from 78% to 100%. The technical component scores for fluoroscopic guidance improved from 58.8 to 52.9. Technical score for computed tomography—navigated guidance also improved from 28.3 to 26.6. CONCLUSION: Didactic and technical quantitative scores with a simulator-based educational curriculum improved objectively measured resident performance. A minimally invasive spine simulation model and curriculum may serve a valuable function in the education of neurosurgical residents and outcomes for patients.

Sign in / Sign up

Export Citation Format

Share Document