Biomechanical comparison of two ostectomy configurations for partial mandibulectomy

2017 ◽  
Vol 30 (01) ◽  
pp. 15-19 ◽  
Author(s):  
Brad Matz ◽  
Ramsis Farag ◽  
Harry Boothe ◽  
D. Tillson ◽  
Ralph Henderson ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Clinical Relevance ◽  
Maximum Load ◽  
Mechanical Advantage ◽  
Biomechanical Assessment ◽  
Significant Difference ◽  
Load To Failure ◽  
Distal Aspect ◽  
Biomechanical Comparison ◽  
Alveolar Surface

SummaryObjective: To determine the stiffness and load to failure of two different ostectomy configurations using canine mandibles.Study design: Cadaveric biomechanical assessment.Animals: Paired mandibles (n = 30).Methods: Standardized partial ostectomies were created on the alveolar surface of 30 mandibles. Samples were randomly assigned to right-angled (n = 15) or crescentic ostectomy (n = 15). Excision spanned the mesial aspect of the fourth premolar tooth to the distal aspect of first molar tooth. Mandibles were loaded to failure in three-point ben-ding. The stiffness, displacement at maximum load, and load to failure were measured.Results: There was no significant difference in stiffness (p = 0.59), displacement at maximum load (p = 0.16) and load to failure (p = 0.76) between right-angled or crescentic ostectomy. Right-angled and crescentic ostectomy failed mostly by fracture through an empty alveolus (11/15 and 13/15, respectively).Clinical relevance: No significant differences in load to failure or stiffness between ostectomy techniques were observed. Crescentic ostectomy did not improve the acute load to failure for partial mandibulectomy. The empty alveolus served as a focal stress concentration point eliminating the potential mechanical advantage of a crescentic ostectomy.

scholarly journals Biomechanical Strength of Scaphoid Partial Unions

2018 ◽  
Vol 07 (05) ◽  
pp. 399-403 ◽  
Author(s):  
Mark Snoddy ◽  
Donald Lee ◽  
Marc Richard ◽  
Mihir Desai ◽  
Adam Brekke
Keyword(s):  
Failure Mechanism ◽  
Clinical Relevance ◽  
Permanent Deformation ◽  
Maximum Load ◽  
Control Group ◽  
Average Maximum ◽  
Significant Difference ◽  
Load To Failure ◽  
Biomechanical Strength ◽  
Inherent Stability

Background It remains unknown how much force a partially united scaphoid can sustain without refracturing. This is critical in determining when to discontinue immobilization in active individuals. Purpose The purpose of this study was to test the biomechanical strength of simulated partially united scaphoids. We hypothesized that no difference would exist in load-to-failure or failure mechanism in scaphoids with 50% or more bone at the waist versus intact scaphoids. Materials and Methods Forty-one cadaver scaphoids were divided into four groups, three experimental osteotomy groups (25, 50, and 75% of the scaphoid waist) and one control group. Each was subjected to a physiologic cantilever force of 80 to 120 N for 4,000 cycles, followed by load to failure. Permanent deformation during physiologic testing and stiffness, max force, work-to-failure, and failure mechanism during load to failure were recorded. Results All scaphoids survived subfailure conditioning with no significant difference in permanent deformation. Intact scaphoids endured an average maximum load to failure of 334 versus 321, 297, and 342 N for 25, 50, and 75% groups, respectively, with no significant variance. There were no significant differences in stiffness or work to failure between intact, 25, 50, and 75% groups. One specimen from each osteotomy group failed by fracturing through the osteotomy; all others failed near the distal pole loading site. Conclusion All groups behaved similarly under physiologic and load-to-failure testing, suggesting that inherent stability is maintained with at least 25% of the scaphoid waist intact. Clinical Relevance The data provide valuable information regarding partial scaphoid union and supports mobilization once 25% union is achieved.

scholarly journals A biomechanical comparison of different tying techniques of a double-stranded looped suture

2019 ◽  
Vol 27 (3) ◽  
pp. 230949901988830
Author(s):  
Suriya Luenam ◽  
Poonsak Koonalinthip ◽  
Arkaphat Kosiyatrakul
Keyword(s):  
Statistical Significance ◽  
Testing Machine ◽  
Security Assessment ◽  
Load Testing ◽  
Loading Test ◽  
Significant Difference ◽  
Load To Failure ◽  
Biomechanical Comparison ◽  
Knot Security ◽  
Loop Security

Purpose: This study aims to assess the biomechanical performance of different tying techniques of a double-stranded looped suture (DSLS). Methods: Loop and knot security of DSLS tying techniques (nice knot (NK), modified nice knot (MNK), double-twist knot (DTK), and double-barrel knot (DBK)) were compared. The square knot of DSLS (SKD) and the square knot of single-stranded suture (SKS) had been used as references. Twenty-four loops of each configuration were created using No. 2 Fiberwire (Arthrex, Naples, Florida, USA) and tested with a material testing machine. Samples were loaded with 10 N preloads for loop security assessment. Knot security was subsequently evaluated. Twelve loops of each knot were loaded to failure. The rest were subjected to cyclic load testing and the elongation at the 50th and 1000th cycles were measured. Knot bulkiness was determined by measuring knot height before testing. Data were compared with analysis of variance and post hoc tests. Statistical significance was p < 0.05. Results: All knots showed no statistically significant difference in displacement with preload. The load-to-failure was highest in NK, followed by MNK, DTK, DBK, SKD, and SKS. The cyclic loading test at the 50th cycle and the 1000th cycle demonstrated that NK has significantly less displacement than the others except MNK. DTK provided a minimal average knot height followed by NK, SKS, DBK, MNK, and SKD. Conclusion: The different tying techniques in DSLS provided the similar loop security but different knot security and knot bulkiness. NK and MNK are biomechanically superior to the other knots, whereas DTK is the least bulky. The findings in the present study may help set the guide for the surgeons to select the tying technique of DSLS to best suit their requirement.

A Biomechanical Comparison of Composite Fixation and Veterinary Acetabular Plates for Stabilization of Acetabular Osteotomies in Dogs Loaded in Three-Point-Bending Fashion

1998 ◽  
Vol 11 (03) ◽  
pp. 152-157 ◽  
Author(s):  
D. D. Lewis ◽  
J. B. Madison ◽  
L. L. Blaeser ◽  
O. I. Ianz
Keyword(s):  
Yield Point ◽  
In Vitro Study ◽  
Maximum Load ◽  
Fixation Method ◽  
Three Point Bending ◽  
Mixed Breed ◽  
Significant Difference ◽  
Biomechanical Comparison ◽  
In Vitro Comparison

SummaryAn in vitro study comparing the biomechanical performance and accuracy of reduction for two methods of acetabular osteotomy repair in the dog is presented. Pelves were harvested from five adult mixed breed dogs weighing 25-30 kg. On e hemipelvis from each dog was repaired with the composite fixation and the contralateral hemipelvis was repaired with a 2.0 mm six hole veterinary acetabular plate. Eac h hemipelvis was loaded in a threepoint- bending fashion at a rate of 5 mm/min. An extensometer was placed over the dorso-medial surface of the acetabular osteotomy during loading. Reduction was significantly better for hemipelves stabilized with the composite fixation when compared to hemipelves stabilized with the 2.0 mm six hole veterinary acetabular plate. There was not a significant difference in bending stiffness, distractional stiffness, yield point and maximum load between repair groups.An in vitro comparison was made between a composite fixation method and acetabular plates for the stabilisation of acetabular osteotomies.

scholarly journals Anatomic Knot Suture Anchor Versus Knotless Suture Anchor Technique for Anterior Talofibular Ligament Repair: A Biomechanical Comparison

2020 ◽  
Vol 8 (1) ◽  
pp. 232596711989812
Author(s):  
Hong Li ◽  
Hanlin Xu ◽  
Yinghui Hua ◽  
Wenbo Chen ◽  
Hongyun Li ◽  
...  
Keyword(s):  
Suture Anchor ◽  
Anterior Talofibular Ligament ◽  
Significant Difference ◽  
Load To Failure ◽  
Group A ◽  
The Mean ◽  
Group B ◽  
Biomechanical Comparison ◽  
Group D ◽  
Suture Anchor Repair

Background: To date, there are few biomechanical studies comparing the strength between knot repair and knotless repair procedures for anterior talofibular ligament (ATFL) injury. Purpose: To perform a biomechanical comparison of the strength of the arthroscopic ATFL repair technique with knot or knotless suture anchors in a cadaveric model with partial or complete ATFL injuries. Study Design: Controlled laboratory study. Methods: A total of 24 fresh-frozen cadaveric ankles were used. Arthroscopy was used to identify, section, and repair the ATFL on the fibular insertion site. The specimens were then randomly placed into 1 of 4 groups: group A received complete ATFL section and 1–suture anchor repair with knot, group B received complete ATFL section and 1-anchor knotless repair, group C received partial ATFL section and 1–suture anchor repair with knot, and group D received partial ATFL section and 1-anchor knotless repair. After repair, the ATFL tension was measured first with a digitalized tensiometer. Specimens were then mounted on a materials testing system to determine the ultimate load to failure and stiffness. Results: The mean ± SD ligament tension measured during the arthroscopic procedure was 8.6 ± 0.6 N for group A, 9.2 ± 0.5 N for group B, 9.4 ± 1.1 N for group C, and 9.6 ± 0.9 N for group D. No significant difference in tension was detected among groups. In load-to-failure testing, the mean ultimate failure load was 27.9 ± 4.1 N for group A, 26.2 ± 9.3 N for group B, 81.9 ± 26.5 N for group C, and 88.1 ± 41.6 N for group D. The mean ultimate failure loads of the partial repair groups were significantly higher than those of the complete repair groups (C vs A, P = .008; D vs B, P = .002), while there was no significant difference between groups A and B ( P > .05) or between groups C and D ( P > .05). Conclusion: The results of the present study showed that there was no significant difference in biomechanical properties between knot repair and knotless repair techniques. Clinical Relevance: Biomechanically, the results showed that knot suture anchor and knotless suture repair provide similar biomechanical strength for ATFL injury. Unfortunately, these methods in the complete ATFL section models provided less than half the strength and stiffness in the partial ATFL section models at time zero after surgery. As a result, 1–suture anchor repair is not suitable for complete ATFL injury regardless of the repair method.

scholarly journals Ordinary Cannulated Compression Screws or Headless Cannulated Compression Screws? A Synthetic Bone Biomechanical Research in the Internal Fixation of Vertical Femoral Neck Fracture

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Baokun Zhang ◽  
Jingwen Liu ◽  
Wei Zhang
Keyword(s):  
Compressive Strength ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Maximum Load ◽  
Biomechanical Stability ◽  
Compression Screw ◽  
Significant Difference ◽  
Load To Failure ◽  
Neck Fracture ◽  
3D Printed

Purpose. The purpose of this study is to verify whether the headless cannulated compression screw (HCCS) has higher biomechanical stability than the ordinary cannulated compression screw (OCCS) in the treatment of vertical femoral neck fractures. Materials and Methods. 30 synthetic femur models were equally divided into 2 groups, with 50°, 60°, and 70° Pauwels angle of femoral neck fracture, under 3D printed guiding plates and C-arm fluoroscopic guidance. The femur molds were fixed with three parallel OCCSs as OCCS group and three parallel HCCSs as HCCS group. All specimens were tested for compressive strength and maximum load to failure with a loading rate of 2 mm/min. Results. The result showed that there was no significant difference with the compressive strength in the Pauwels angle of 50° and 60°. However, we observed that the maximum load to failure with the Pauwels angle of 50°, 60°, and 70° and the compressive strength with 70° of HCCS group showed better performance than the OCCS group. Conclusion. HCCS performs with better biomechanical stability than OCCS in the treatment of vertical femoral neck fracture, especially with the Pauwels angle of 70°.

scholarly journals Biomechanical Comparison of a Prepared Thick Fresh Frozen Irradiated Fascia Lata Allograft to the Native Superior Capsule (212)

2021 ◽  
Vol 9 (10_suppl5) ◽  
pp. 2325967121S0032
Author(s):  
Nicholas Debellis ◽  
John Manning ◽  
James Tibone ◽  
Michelle McGarry ◽  
Gregory Adamson ◽  
...  
Keyword(s):  
Ultimate Load ◽  
Fascia Lata ◽  
Cadaveric Specimen ◽  
Yield Load ◽  
Total Displacement ◽  
Pull Out ◽  
Significant Difference ◽  
Load To Failure ◽  
Fresh Frozen ◽  
Biomechanical Comparison

Objectives: Superior Capsule Reconstruction (SCR) has been described as treatment option for irreparable tears of the superior rotator cuff. Reported outcomes on the success of the surgery have been variable, with graft choice seeming to be one of the most important factors. Fascia Lata (FL) allograft has been proposed as a potential option as it provides adequate graft thickness while avoiding the morbidity of an autograft harvest. The purpose of this study was to compare the biomechanical characteristics of an SCR with FL allograft (FL-SCR) to a native superior capsule in a cadaveric specimen. Methods: Eight cadaver shoulder specimens were used. Each specimen was tested with a custom shoulder system twice. Initial testing was performed after the specimen was dissected of all soft tissue except for the native superior capsule. Subsequent testing was performed after FL-SCR was done. All allografts were fresh frozen and irradiated. Capsule and graft dimensions were recorded before testing. Biomechanical values recorded were cyclic and load to failure for both the native capsule and FL-SCR, and fixation displacement for the SCR-FL construct. A Paired T-test was performed to compare the biomechanical values of the native superior capsule to the FL-SCR. Results: The mean thickness of the NSC was 2.4 ± 0.6 mm and 7.4 ± 1.2mm for the FL graft. The native superior capsule had an average linear stiffness of 94.5 ± 20.4 N/mm, yield load of 386.9 ± 63.6 N, ultimate load of 444.9 ± 67.7 N and energy absorbed of 1418.4 ± 248.8 N-mm. The FL-SCR construct had an average linear stiffness of 28.0 ± 1.6 N/mm, yield load of 123.8 ± 54.3 N, ultimate load of 369.0 ± 43.4 N and energy absorbed of 5021.2 ± 755.1 N-mm. Comparing the two groups there was a statistically significant difference for stiffness (P = 0.013), yield load (P = 0.03) and energy absorbed (P = 0.003). There was no statistically significant difference between ultimate load. The total displacement of the FL-SCR fixation was 5.8 ± 0.6 mm after 1 cycle, 8.5 ± 0.7 mm after 30 cycles, 11.4 ± 1.8 mm at the yield load and 29.5 ± 1.8 mm at the ultimate load. For the failure mode, 8/8 NSC specimens failed at the mid-substance. The FL-SCR, 3/8 specimens failed at the suture tendon interface and 4/8 had medial anchor pull out. Conclusions: Performing SCR with FL allograft in a cadaver model creates a construct that is sufficiently strong enough to withstand normal physiologic loading of the shoulder, although it does not fully re-create the biomechanical characteristics of a native shoulder superior capsule.

Single Versus Dual Headless Compression Screw Fixation of Scaphoid Nonunions: A Biomechanical Comparison

Hand ◽  
2021 ◽  
pp. 155894472097411
Author(s):  
Luke T. Nicholson ◽  
Kristen M. Sochol ◽  
Ali Azad ◽  
Ram Kiran Alluri ◽  
J. Ryan Hill ◽  
...  
Keyword(s):  
Screw Fixation ◽  
Qualitative Assessment ◽  
Secondary Outcome ◽  
Scaphoid Nonunion ◽  
Compression Screw ◽  
Single Screw ◽  
Headless Compression Screw ◽  
Significant Difference ◽  
Load To Failure ◽  
Headless Compression Screws

Background: Management of scaphoid nonunions with bone loss varies substantially. Commonly, internal fixation consists of a single headless compression screw. Recently, some authors have reported on the theoretical benefits of dual-screw fixation. We hypothesized that using 2 headless compression screws would impart improved stiffness over a single-screw construct. Methods: Using a cadaveric model, we compared biomechanical characteristics of a single tapered 3.5- to 3.6-mm headless compression screw with 2 tapered 2.5- to 2.8-mm headless compression screws in a scaphoid waist nonunion model. The primary outcome measurement was construct stiffness. Secondary outcome measurements included load at 1 and 2 mm of displacement, load to failure for each specimen, and qualitative assessment of mode of failure. Results: Stiffness during load to failure was not significantly different between single- and double-screw configurations ( P = .8). Load to failure demonstrated no statistically significant difference between single- and double-screw configurations. Using a qualitative assessment, the double-screw construct maintained rotational stability more than the single-screw construct ( P = .029). Conclusions: Single- and double-screw fixation constructs in a cadaveric scaphoid nonunion model demonstrate similar construct stiffness, load to failure, and load to 1- and 2-mm displacement. Modes of failure may differ between constructs and represent an area for further study. The theoretical benefit of dual-screw fixation should be weighed against the morphologic limitations to placing 2 screws in a scaphoid nonunion.

scholarly journals Morphological Changes of the Hip Commonly Associated With Femoroacetabular Impingement Are Not Correlated With Rotational Range of Hip Motion in Elite Soccer Athletes

2021 ◽  
pp. 194173812097366
Author(s):  
André Orlandi Bento ◽  
Guilherme Falótico ◽  
Keelan Enseki ◽  
Ronaldo Alves Cunha ◽  
Benno Ejnisman ◽  
...  
Keyword(s):  
Femoroacetabular Impingement ◽  
Lower Limb ◽  
Clinical Relevance ◽  
Morphological Changes ◽  
Alpha Angle ◽  
Soccer Players ◽  
Level Of Evidence ◽  
Rotational Movement ◽  
Professional Soccer ◽  
Significant Difference

Background: Morphological changes characteristic of femoroacetabular impingement (FAI) are common in soccer players. However, the clinical relevance of such anatomical variations is still not well-defined. Hypothesis: We hypothesized that high alpha angle values and/or acetabular retroversion index (ARI) are correlated with rotational range of motion (ROM) of the hip and that there are clinical-radiological diferences between the dominant lower limb (DLL) and nondominant lower limb (NDLL) in professional soccer players. Study Design: Cross-sectional. Level of Evidence: Level 3. Methods: A total of 59 male professional soccer players (average age 25.5 years, range 18-38 years) were evaluated in the preseason. As main outcome measures, we evaluated the alpha angle and the ARI and hip IR and ER ROM with radiographic analysis. Results: The measurements taken on DLL and NDLL were compared and a significant difference was found between the sides in the ER ( P = 0.027), where the DLL measures were 1.54° (95% CI, 0.18-2.89) greater than the NDLL. There were no significant differences between the sides in the measures of IR ( P > 0.99), total ROM ( P = 0.07), alpha angle ( P = 0.250), and ARI ( P = 0.079). The correlations between the rotation measurements and the alpha angle in each limb were evaluated and the coefficient values showed no correlation; so also between the ARI and rotation measures. Conclusion: Morphological changes of the femur or acetabulum are not correlated with hip IR and ER ROM in male professional soccer players. ER on the dominant side was greater than on the nondominant side. There was no significant difference in the other measurements between sides. Clinical Relevance: In clinical practice, it is common to attribute loss of hip rotational movement to the presence of FAI. This study shows that anatomical FAI may not have a very strong influence on available hip rotational movement in professional soccer athletes.

scholarly journals Interference Screw Versus Suture Anchors for Femoral Fixation in Medial Patellofemoral Ligament Reconstruction: A Biomechanical Study

2021 ◽  
Vol 9 (3) ◽  
pp. 232596712198928
Author(s):  
Heath P. Gould ◽  
Nicholas R. Delaney ◽  
Brent G. Parks ◽  
Roshan T. Melvani ◽  
Richard Y. Hinton
Keyword(s):  
Medial Patellofemoral Ligament ◽  
Interference Screw ◽  
Biomechanical Study ◽  
Graft Fixation ◽  
Mpfl Reconstruction ◽  
Suture Anchors ◽  
Femoral Fixation ◽  
Significant Difference ◽  
Load To Failure ◽  
The Mean

Background: Femoral-sided graft fixation in medial patellofemoral ligament (MPFL) reconstruction is commonly performed using an interference screw (IS). However, the IS method is associated with several clinical disadvantages that may be ameliorated by the use of suture anchors (SAs) for femoral fixation. Purpose: To compare the load to failure and stiffness of SAs versus an IS for the femoral fixation of a semitendinosus autograft in MPFL reconstruction. Study Design: Controlled laboratory study. Methods: Based on a priori power analysis, a total of 6 matched pairs of cadaveric knees were included. Specimens in each pair were randomly assigned to receive either SA or IS fixation. After an appropriate reconstruction procedure, the looped end of the MPFL graft was pulled laterally at a rate of 6 mm/s until construct failure. The best-fit slope of the load-displacement curve was then used to calculate the stiffness (N/mm) in a post hoc fashion. A paired t test was used to compare the mean load to failure and the mean stiffness between groups. Results: No significant difference in load to failure was observed between the IS and the SA fixation groups (294.0 ± 61.1 vs 250.0 ± 55.9; P = .352), although the mean stiffness was significantly higher in IS specimens (34.5 ± 9.6 vs 14.7 ± 1.2; P = .004). All IS reconstructions failed by graft pullout from the femoral tunnel, whereas 5 of the 6 SA reconstructions failed by anchor pullout. Conclusion: In this biomechanical study using a cadaveric model of MPFL reconstruction, SA femoral fixation was not significantly different from IS fixation in terms of load to failure. The mean load-to-failure values for both reconstruction techniques were greater than the literature-reported values for the native MPFL. Clinical Relevance: These results suggest that SAs are a biomechanically viable alternative for femoral-sided graft fixation in MPFL reconstruction.

scholarly journals Biomechanical stability of complex coronal plane fracture fixation of the capitellum

2021 ◽  
Author(s):  
Paul Borbas ◽  
Rafael Loucas ◽  
Marios Loucas ◽  
Maximilian Vetter ◽  
Simon Hofstede ◽  
...  
Keyword(s):  
Fracture Fixation ◽  
Ultimate Load ◽  
Locking Plate ◽  
Distal Humerus ◽  
Coronal Plane ◽  
Fixation Strength ◽  
Biomechanical Stability ◽  
Significant Difference ◽  
Load To Failure ◽  
Headless Compression Screws

Abstract Introduction Coronal plane fractures of the distal humerus are relatively rare and can be challenging to treat due to their complexity and intra-articular nature. There is no gold standard for surgical management of these complex fractures. The purpose of this study was to compare the biomechanical stability and strength of two different internal fixation techniques for complex coronal plane fractures of the capitellum with posterior comminution. Materials and methods Fourteen fresh frozen, age- and gender-matched cadaveric elbows were 3D-navigated osteotomized simulating a Dubberley type IIB fracture. Specimens were randomized into one of two treatment groups and stabilized with an anterior antiglide plate with additional anteroposterior cannulated headless compression screws (group antiGP + HCS) or a posterolateral distal humerus locking plate with lateral extension (group PLP). Cyclic testing was performed with 75 N over 2000 cycles and ultimately until construct failure. Data were analyzed for displacement, construct stiffness, and ultimate load to failure. Results There was no significant difference in displacement during 2000 cycles (p = 0.291), stiffness (310 vs. 347 N/mm; p = 0.612) or ultimate load to failure (649 ± 351 vs. 887 ± 187 N; p = 0.140) between the two groups. Conclusions Posterolateral distal humerus locking plate achieves equal biomechanical fixation strength as an anterior antiglide plate with additional anteroposterior cannulated headless compression screws for fracture fixation of complex coronal plane fractures of the capitellum. These results support the use of a posterolateral distal humerus locking plate considering the clinical advantages of less invasive surgery and extraarticular metalware. Level of evidence Biomechanical study.

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