scholarly journals Anterior Glenoid Reconstruction With Distal Tibial Allograft: Biomechanical Impact of Fixation and Presence of a Retained Lateral Cortex

2021 ◽  
Vol 9 (11) ◽  
pp. 232596712110504
Author(s):  
Stephen A. Parada ◽  
K. Aaron Shaw ◽  
Meghan E. McGee-Lawrence ◽  
Judith G. Kyrkos ◽  
Daniel W. Paré ◽  
...  
Keyword(s):  
Peak Torque ◽  
Biomechanical Analysis ◽  
Materials Testing ◽  
Glenohumeral Instability ◽  
Lateral Cortex ◽  
Screw Insertion ◽  
Native Bone ◽  
Load To Failure ◽  
Anterior Glenoid ◽  
Glenoid Reconstruction

Background: Glenoid reconstruction with distal tibial allograft (DTA) is a known surgical option for treating recurrent glenohumeral instability with anterior glenoid bone loss; however, biomechanical analysis has yet to determine how graft variability and fixation options alter the torque of screw insertion and load to failure. Hypothesis: It was hypothesized that retention of the lateral cortex of the DTA graft and the presence of a washer with the screw will significantly increase the maximum screw placement torque as well as the load to failure. Study Design: Controlled laboratory study. Methods: Whole, fresh distal tibias were used to harvest 28 DTA grafts, half of which had the lateral cortex removed and half of which had the lateral cortex intact. The grafts were secured to polyurethane solid foam blocks with a 2-mm epoxy laminate to simulate a glenoid with an intact posterior glenoid cortex. Grafts underwent fixation with 4.0-mm cannulated drills, and screws and washers were used for half of each group of grafts while screws alone were used for the other half, creating 4 equal groups of 7 samples each. A digital torque-measuring screwdriver recorded peak torque for screw insertion. Constructs were then tested in compression with a uniaxial materials testing system and loaded in displacement control at 100 mm/min until at least 3 mm of displacement occurred. Ultimate load was defined as the load sustained at clinical failure. Results: The use of a washer significantly improved the ultimate torque that could be applied to the screws (+cortex and +washer = 12.42 N·m [SE, 0.82]; –cortex and +washer = 10.54 N·m [SE, 0.59]) ( P < .0001), whereas the presence of the native bone cortex did not have a significant effect (+cortex and –washer = 7.83 N·m [SE, 0.40]; –cortex and –washer = 8.03 N·m [SE, 0.56]) ( P = .181). Conclusion: In a hybrid construct of fresh cadaveric DTA grafts secured to a foam block glenoid model, the addition of washers was more effective than the retention of the lateral distal tibial cortex for both load to failure and peak torque during screw insertion. Clinical Relevance: This biomechanical study is relevant to the surgeon when choosing a graft and selecting fixation options during glenoid reconstruction with a DTA graft.

Plantar-to-Dorsal Compared to Dorsal-to-Plantar Screw Fixation for Proximal Chevron Osteotomy: A Biomechanical Analysis

2005 ◽  
Vol 26 (10) ◽  
pp. 854-858 ◽  
Author(s):  
Krishn M. Sharma ◽  
Brent G. Parks ◽  
Augustine Nguyen ◽  
Lew C. Schon
Keyword(s):  
Screw Fixation ◽  
Biomechanical Analysis ◽  
Fixation Method ◽  
Materials Testing ◽  
Metatarsal Osteotomy ◽  
First Metatarsal ◽  
Lag Screw ◽  
Chevron Osteotomy ◽  
Plantar Aspect ◽  
Load To Failure

Background: A change in screw orientation in fixing the chevron proximal first metatarsal osteotomy was noted anecdotally to improve fixation strength. The authors hypothesized that plantar-to-dorsal screw orientation would be more stable than the conventional dorsal-to-plantar screw orientation for fixation of the chevron osteotomy. The purpose of this study was to determine if the load-to-failure and stiffness of the chevron type proximal first metatarsal osteotomy stabilized using plantar-to-dorsal screw fixation were greater than with the more conventional dorsal-to-plantar screw fixation method. Methods: One foot from each of eight matched cadaver pairs was randomly assigned to one of two groups: 1) fixation with a dorsal-to-plantar lag screw or 2) fixation with a plantar-to-dorsal lag screw. A proximal chevron osteotomy was then created using standard technique and the metatarsal was fixed according to previously established method. The bone was potted in polyester resin, and the construct was fitted into a materials testing system machine in which load was applied to the plantar aspect of the metatarsal until failure. The two groups were compared using a two-tailed Student t test. Results: The average load-to-failure and stiffness of the chevron osteotomy fixed with the plantar-to-dorsal lag screw were significantly greater ( p < 0.05) than the group fixed with more conventional dorsal-to-plantar lag screws. Conclusion: Plantar-to-dorsal screw orientation was more stable than the conventional dorsal-to-plantar screw orientation for fixation of the proximal chevron osteotomy. Plantar-to-dorsal screw orientation should be considered when using the chevron proximal first metatarsal osteotomy.

scholarly journals Mechanical torque measurement in the proximal femur correlates to failure load and bone mineral density ex vivo

2013 ◽  
Vol 5 (2) ◽  
pp. 16 ◽  
Author(s):  
Stefan Grote ◽  
Tatjana Noeldeke ◽  
Michael Blauth ◽  
Wolf Mutschler ◽  
Dominik Bürklein
Keyword(s):  
Bone Mineral Density ◽  
Femoral Neck ◽  
Bone Quality ◽  
Bone Mineral ◽  
Proximal Femur ◽  
Failure Load ◽  
Peak Torque ◽  
Mineral Density ◽  
Local Bone ◽  
Load To Failure

Knowledge of local bone quality is essential for surgeons to determine operation techniques. A device for intraoperative measurement of local bone quality has been developed by the AO-Research Foundation (DensiProbe®). We used this device to experimentally measure peak breakaway torque of trabecular bone in the proximal femur and correlated this with local bone mineral density (BMD) and failure load. Bone mineral density of 160 cadaver femurs was measured by <em>ex situ </em>dual-energy X-ray absorptiometry. The failure load of all femurs was analyzed by side-impact analysis. Femur fractures were fixed and mechanical peak torque was measured with the DensiProbe® device. Correlation was calculated whereas correlation coefficient and significance was calculated by Fisher’s Z-transformation. Moreover, linear regression analysis was carried out. The unpaired Student’s t-test was used to assess the significance of differences. The Ward triangle region had the lowest BMD with 0.511 g/cm2 (±0.17 g/cm2), followed by the upper neck region with 0.546 g/cm2 (±0.16 g/cm2), trochanteric region with 0.685 g/cm2 (±0.19 g/cm2) and the femoral neck with 0.813 g/cm2 (±0.2 g/cm2). Peak torque of DensiProbe® in the femoral head was 3.48 Nm (±2.34 Nm). Load to failure was 4050.2 N (±1586.7 N). The highest correlation of peak torque measured by Densi Probe® and load to failure was found in the femoral neck (r=0.64, P&lt;0.001). The overall correlation of mechanical peak torque with T-score was r=0.60 (P&lt;0.001). A correlation was found between mechanical peak torque, load to failure of bone and BMD <em>in vitro</em>. Trabecular strength of bone and bone mineral density are different aspects of bone strength, but a correlation was found between them. Mechanical peak torque as measured may contribute additional information about bone strength, especially in the perioperative testing.

Biomechanical Analysis of a Double-Loaded Glenoid Anchor Configuration

2012 ◽  
Vol 41 (1) ◽  
pp. 163-168 ◽  
Author(s):  
Ganesh V. Kamath ◽  
Stephen Hoover ◽  
R. Alexander Creighton ◽  
Paul Weinhold ◽  
Aaron Barrow ◽  
...  
Keyword(s):  
Tensile Load ◽  
The Other ◽  
Biomechanical Analysis ◽  
Bankart Repair ◽  
Matched Pair ◽  
Materials Testing ◽  
Testing Device ◽  
Suture Anchors ◽  
Variable Reluctance ◽  
Biomechanical Strength

Background: Bankart repair with multiple anchor holes concentrated in the anterior-inferior glenoid may contribute to glenoid weakening and potentially may induce glenoid failure. Purpose: To compare the biomechanical strength of a Bankart repair construct that used 3 single-loaded suture anchors versus a repair construct that used 2 double-loaded suture anchors. Study Design: Comparative laboratory study. Methods: A standard Bankart lesion was created in 18 human cadaveric shoulders (9 matched pairs). Within each matched pair, 1 repair construct used 3 single-loaded anchors, whereas the other used 2 double-loaded suture anchors. Measured outcomes (load, stiffness, and energy absorbed) were recorded at failure and at 2 mm of labral displacement. Constructs were loaded to failure with a materials testing device that had differential variable reluctance transducers for displacement measurements. Results: The double-loaded anchor construct had a significantly higher ultimate tensile load (944 ± 231 vs 784 ± 287 N; P = .03). For the other measures (load at 2 mm of displacement, energy absorbed at failure and at 2 mm of displacement and stiffness), there were no significant differences between tested constructs. Conclusion: A Bankart repair construct that used 2 double-loaded anchors was either superior to or equal to a repair construct that used 3 single-loaded anchors in all measured outcomes. Clinical Relevance: Using 2 double-loaded suture anchors for a Bankart repair may limit anchor holes in the glenoid and reduce the risk of postsurgical glenoid fracture while providing a stable repair construct.

scholarly journals A biomechanical analysis of tibial ACL reconstruction with graft length mismatch

2017 ◽  
Vol 25 (1) ◽  
pp. 230949901769098
Author(s):  
Evan B Gaines ◽  
Diana Lau ◽  
Qais Naziri ◽  
Westley Hayes ◽  
Julio J. Jauregui ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Acl Reconstruction ◽  
Surgical Techniques ◽  
The Other ◽  
Biomechanical Analysis ◽  
Graft Fixation ◽  
Bptb Graft ◽  
Load To Failure ◽  
Group 3 ◽  
Graft Length

Introduction: The incidence of graft length mismatch (GLM) during anterior cruciate ligament (ACL) reconstruction is reported to be up to 13%, with a rate of 20% when using bone-patellar tendon-bone (BPTB) allografts. Multiple techniques have been described to accommodate for the longer BPTB graft. As no study has compared the biomechanical properties of these methods (with cyclic loading), we evaluated the strength of four different surgical techniques used to accommodate for GLM during ACL reconstruction. Methods: A total of 32 fresh-frozen bovine tibiae and patellar tendons were divided into four groups based on the method of tibial graft fixation: (1) sutures tied over a post, (2) bone staples, (3) screws and washers, and (4) soft-tissue conversion with interference screw. Biomechanical testing was performed comparing the tensile properties of graft fixation techniques under cyclic loading. Ability to withstand 1500 cycles of load, the maximum tensile strength at load-to-failure, and the mode-of-failure were evaluated. Results: Only group 4 had all grafts intact after 1500 loading cycles, while the other groups had one graft failure at 338 (group 1), 240 (group 2), and 309 (group 3) cycles. The highest mean load-to-failure was observed in group 3 at 762 ± 173 N, which was found to be significantly higher than the other groups. The mean loads to failure in groups 1–4 were 453 ± 86 N, 485 ± 246 N, 762 ± 173 N, and 458 ± 128 N. Conclusion: While there are multiple viable techniques for fixation of a BPTB graft in the case of GLM, this study demonstrated that direct screw fixation offers the strongest construct.

Comparative Evaluation of Bone Suture Anchor to Bone Tunnel Fixation of Tibialis Anterior Tendon in Cadaveric Cuboid Bone: A Biomechanical Investigation

1995 ◽  
Vol 16 (10) ◽  
pp. 641-645 ◽  
Author(s):  
Colin W. Fennell ◽  
John M. Ballard ◽  
Daniel S. Pflaster ◽  
Rodney H. Adkins
Keyword(s):  
Tibialis Anterior ◽  
Suture Anchor ◽  
Biomechanical Study ◽  
Bone Tunnel ◽  
Biomechanical Analysis ◽  
Tibialis Anterior Tendon ◽  
Cuboid Bone ◽  
Load To Failure ◽  
Bone Tunnels

A multiphase biomechanical study was performed using human tibialis anterior tendons and cuboid bones, comparing the fixation of the tendon to the bone using bone anchors and bone tunnels. Twenty-six specimens were tested for ultimate load to failure comparing Mitek Superanchor fixation with no. 1 and no. 5 braided polyethelyne suture to bone tunnel fixation. Mitek Superanchor with no. 5 suture failed at 223 N, compared with Mitek Superanchor with no. 1 suture at 134 N and bone tunnel at 143 N ( P = 0.033). Mitek with no. 1 suture versus bone tunnel was not significantly different. The Mitek with no. 5 suture failed at the tendon/suture interface (75%), the Mitek with no. 1 suture failed at the suture/anchor interface (56%), and bone tunnel fixation failed most commonly by fracture of the tunnel (76%). This study is the first biomechanical analysis of the pullout strengths of bone tunnels or suture anchors in the cuboid bone. We have shown that the suture anchor has a pullout strength comparable or superior to a conventional bone tunnel in an in vitro situation. We believe it is a viable alternative to fixation of the tibialis anterior tendon to the cuboid when there is insufficient tendon length or failure of the bone tunnel.

scholarly journals Biomechanical Analysis of the Efficacy of Locking Plates during Cyclic Loading in Metacarpal Fractures

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Stefanie Doht ◽  
Rainer H. Meffert ◽  
Michael J. Raschke ◽  
Torsten Blunk ◽  
Sabine Ochman
Keyword(s):  
Cyclic Loading ◽  
Locking Plate ◽  
Screw Fixation ◽  
Maximum Load ◽  
Biomechanical Analysis ◽  
Locking Plates ◽  
Functional Rehabilitation ◽  
Metacarpal Bones ◽  
Load To Failure ◽  
Bicortical Screw

Purpose.To analyse the biomechanical characteristics of locking plates under cyclic loading compared to a nonlocking plate in a diaphyseal metacarpal fracture.Methods.Oblique diaphyseal shaft fractures in porcine metacarpal bones were created in a biomechanical fracture model. An anatomical reduction and stabilization with a nonlocking and a comparable locking plate in mono- or bicortical screw fixation followed. Under cyclic loading, the displacement, and in subsequent load-to-failure tests, the maximum load and stiffness were measured.Results.For the monocortical screw fixation of the locking plate, a similar displacement, maximum load, and stiffness could be demonstrated compared to the bicortical screw fixation of the nonlocking plate.Conclusions.Locking plates in monocortical configuration may function as a useful alternative to the currently common treatment with bicortical fixations. Thereby, irritation of the flexor tendons would be avoided without compromising the stability, thus enabling the necessary early functional rehabilitation.

Biomechanical Analysis of Screw-Augmented Intramedullary Fixation for Tibiotalocalcaneal Arthrodesis

2007 ◽  
Vol 28 (7) ◽  
pp. 804-809 ◽  
Author(s):  
Patrick J. O'Neill ◽  
Brent G. Parks ◽  
Russell Walsh ◽  
Lucia M. Simmons ◽  
Lew C. Schon
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Pearson Correlation ◽  
Significant Negative Correlation ◽  
Biomechanical Analysis ◽  
Complication Rates ◽  
Initial Stiffness ◽  
Mineral Density ◽  
Tibiotalocalcaneal Arthrodesis ◽  
Load To Failure

Background This study compared intramedullary (IM) fixation for tibiotalocalcaneal arthrodesis with and without a tibiotalocalcaneal augmentation screw. Methods Each specimen in six matched pairs of fresh frozen cadavers underwent tibiotalocalcaneal arthrodesis with an IM nail. One specimen from each pair also received a tibiotalocalcaneal augmentation screw. Initial and final stiffness, load to failure, and construct deformation at failure were calculated with dorsiflexion loading. Bone mineral density of each pair was determined. Statistical analysis was done using a paired Student t-test and a Pearson correlation. Results Initial and final stiffness and load to failure were significantly higher for the tibiotalocalcaneal screw augmented fixation group as compared with the specimens with no additional screw (initial stiffness, 128.0 versus 78.4 N/mm, p = 0.04; final stiffness, 230.9 versus 164.7 N/mm, p = 0.04; load to failure, 875.5 versus 660.2 N, p = 0.03). There was a significant negative correlation between bone mineral density and average construct deformation in the samples without the added tibiotalocalcaneal screw ( r = –0.90, p = 0.02). Conclusions In tibiotalocalcaneal arthrodesis with intramedullary nail fixation, a tibiotalocalcaneal augmentation screw provides more stable fixation. Clinical relevance Use of an augmentation screw as described in this study may lead to lower complication rates, particularly in patients with osteopenic bone.

Tibial Fixation of Anterior Cruciate Ligament Allograft Tendons

2009 ◽  
Vol 37 (8) ◽  
pp. 1531-1538 ◽  
Author(s):  
Daniel K. Park ◽  
Harold A. Fogel ◽  
Sanjeev Bhatia ◽  
Bernard R. Bach ◽  
Aman Gupta ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Maximum Load ◽  
Materials Testing ◽  
Tibial Fixation ◽  
Fixation Devices ◽  
Load To Failure ◽  
Fresh Frozen ◽  
Lower Load ◽  
Anterior Cruciate

Background In sum, 1-, 2-, and 4-stranded allografts are used for soft tissue anterior cruciate ligament reconstruction; however, the fixation properties of fixation devices are not well assessed. Hypothesis There are no differences in the biomechanical characteristics of 1 (Achilles)-, 2 (posterior tibialis)-, and 4 (semitendinosus)-stranded allograft tibial fixation. Study Design Controlled laboratory study. Methods Sixty-three fresh-frozen porcine tibiae were used to evaluate the fixation of 1-, 2-, and 4-stranded human tendon allografts (Achilles, posterior tibialis, and semitendinosus) with 3 fixation devices (Delta, Intrafix, and Calaxo screws). With use of a materials testing system, each graft was subjected to 500 cycles of loading (50-250 N, 0.75 mm/sec) to determine displacement and cyclic stiffness, followed by a monotonic failure test (20 mm/min) to determine maximum load and pullout stiffness. Results For each graft type, there were no significant biomechanical differences between fixation devices. However, the 1-stranded graft (Achilles) construct demonstrated significantly higher mean displacement (3.17 ± 1.62 mm), lower cyclical stiffness (156 ± 25 N/mm), lower load to failure (479 ± 87 N), and lower pullout stiffness (140 ± 28 N/mm). In comparison with the 2-stranded graft (posterior tibialis), the 4-stranded graft (semitendinosus) exhibited lower displacement (0.86 ± 0.44 to 1.12 ± 0.51 mm) and higher ultimate failure load (832 ± 255 to 656 ± 168 N). Numerous differences in fixation properties were noted when comparing a device to each of the 3 grafts. Conclusion The 1-stranded allograft demonstrated inferior biomechanical tibial fixation properties when compared with 2 (posterior tibialis)- and 4 (semitendinosus)-stranded allograft constructs for all fixation devices tested. Clinical Relevance This study demonstrated that not all tibial fixation devices are designed to adequately accommodate different types of anterior cruciate ligament allografts. Biomechanical evidence suggests that caution is warranted when using an Achilles allograft fixated solely with an interference device.

A review of bone grafting techniques for glenoid reconstruction

2021 ◽  
pp. 175857322110084
Author(s):  
Jeffrey A Zhang ◽  
Patrick H Lam ◽  
Julia Beretov ◽  
George AC Murrell
Keyword(s):  
Bone Grafting ◽  
Iliac Crest ◽  
Femoral Condyle ◽  
Distal Tibia ◽  
Bone Grafts ◽  
Electronic Search ◽  
Fixation Techniques ◽  
Anterior Glenoid ◽  
Bony Fragment ◽  
Glenoid Reconstruction

Background Traumatic anterior shoulder dislocations can cause bony defects of the anterior glenoid rim and are often associated with recurrent shoulder instability. For large glenoid defects of 20–30% without a mobile bony fragment, glenoid reconstruction with bone grafts is often recommended. This review describes two broad categories of glenoid reconstruction procedures found in literature: coracoid transfers involving the Bristow and Latarjet procedures, and free bone grafting techniques. Methods An electronic search of MEDLINE and PubMed was conducted to find original articles that described glenoid reconstruction techniques or modifications to existing techniques. Results Coracoid transfers involve the Bristow and Latarjet procedures. Modifications to these procedures such as arthroscopic execution, method of graft attachment and orientation have been described. Free bone grafts have been obtained from the iliac crest, distal tibia, acromion, distal clavicle and femoral condyle. Conclusion Both coracoid transfers and free bone grafting procedures are options for reconstructing large bony defects of the anterior glenoid rim and have had similar clinical outcomes. Free bone grafts may offer greater flexibility in graft shaping and choice of graft size depending on the bone stock chosen. Novel developments tend towards minimising invasiveness using arthroscopic approaches and examining alternative non-rigid graft fixation techniques.

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