Mm Of Displacement Research Articles

Impact of Weber B Fracture Displacement on Medial Clear Space Volume: How Much Displacement Matters?

Category:Ankle; Sports; TraumaIntroduction/Purpose:Numerous radiographic studies examining Weber B fibular fractures demonstrate no change in tibiotalar contact area until the deltoid ligament is disrupted. In contrast, more recent studies using weight-bearing CT scan (WBCT) and 3D volume analysis suggest that medial clear space (MCS) volume can in fact increase in the setting of a Weber B fibular fracture even if initial radiographs are reassuring, possibly due to a loss of fibular buttress. This study aims to evaluate the ability of WBCT to quantify the impact of isolated Weber B fractures on MCS volume (3D), as well as understand the implication of increasing fibular displacement among patients with symmetric MCS distance (1D) on initial radiographs.Methods:The study group included 18 patients with unilateral Weber B ankle fractures who underwent preoperative bilateral foot and ankle WBCT. The control group consisted of 60 patients without ankle injury who underwent similar imaging.Measurements on WBCT images included: 1) MCS distance, 2) syndesmotic area, 3) anterior, middle, and posterior distal tibiofibular distance, 4) fibular rotation, 5) distance from fibular tip to plafond, and 6) fibular fracture displacement. Additionally, volumetric measurements included: 1) MCS volume 2) syndesmotic joint volume from the tibial plafond extending to 3cm and 5 cm proximally, and 3) lateral clear space volume were calculated. Area under the receiver operating characteristic (ROC) curve analysis and Delong test were used, and optimal cutoff values to distinguish between stable and unstable Weber B fractures without syndesmotic instability and MCS widening were determined using Youden's J statistic.Results:Among patients with unilateral Weber B ankle fractures, all WBCT measurements showed no side-to-side difference in any parameter, except MCS volume (p-values <0.001). When compared to the uninjured side, fibular displacement up to 2cm and up to 4cm increased lateral MCS volume by 37.1% (0.23cm3) and 51.8% (0.3cm3), respectively. Based on ROC analysis and Youden's J statistic, the optimal threshold for differentiating stable from an unstable Weber B fracture was 2.3 mm of displacement (AUC 0.81; sensitivity 77.8%; specificity 80%). The control group showed no difference in any of the measurements between the two sides.Conclusion:When using WBCT, 3D MCS volume increases significantly with Weber B fibular fractures, even if 1D distance measurements at the medial clear space are reassuring. This is especially true with fibular displacement greater than 2.3mm and may have an important role in the management of SER II ankle fractures.

Isolated Tillaux Fracture in Adults - Literature Review Based on a Rare Case Report.

Isolated Tillaux fracture is a rare anterolateral distal tibia fracture frequently misdiagnosed in adults. It typically occurs in adolescents nearing skeletal maturity by avulsion of the anterior-inferior tibiofibular ligament. This case-based literature review study aims to elicit the existing information regarding this fracture in adults, and summarize its injury mechanism, diagnosis, and treatment procedures. According to the literature, this is only the eighth case described: a 46-year-old woman that suffered an isolated Tillaux fracture with 4 mm of displacement, and open reduction and fixation with double cannulated screws were performed. After proper rehabilitation, an excellent functional and radiological outcome was reached. It is important to recognize and appropriately treat these distinct injuries to prevent further instability, degenerative changes, and ankle joint function limitation. Early diagnosis and appropriate osteosynthesis play a significant role in a successful recovery prognosis.

All-epiphyseal versus trans-epiphyseal screw fixation for tillaux fractures: Does it matter?

BACKGROUNDTillaux fractures occur primarily in adolescents due to the pattern of physeal closure and are classified as Salter-Harris type III physeal fractures. Operative management with screw fixation is recommended for more than 2 mm of displacement or more than 1 mm of translation. However, the efficacy and complications of trans-physeal vs all-physeal screw fixation have not been investigated extensively.AIMTo compare the clinical and functional outcomes of trans-physeal (oblique) and all-epiphyseal (parallel) screw fixation in management of Tillaux fractures among pediatric patients. METHODSThis was an ethics board approved retrospective review of pediatric patients who presented to our tertiary children’s care facility with Tillaux fractures. We included patients who had surgical fixation of a Tillaux fracture over a 10 year period. Data analysis included demographics, mode of injury, management protocols, and functional outcomes. The patients were divided into group 1 (oblique fixation) and group 2 (parallel fixation). Baseline patient characteristics and functional outcomes were compared between groups. Statistical tests to evaluate differences included Fisher’s Exact or Chi-squared and independent samples t or Mann Whitney tests for categorical and continuous variables, respectively.RESULTSA total of 42 patients (28 females and 14 males) were included. There were no significant differences in body mass index, sex, age, or time to surgery between the groups [IK2]. Sports injuries accounted for 61.9% of the cases, particularly non-contact (57.1%) and skating (28.6%) injuries. Computed Tomography (CT) scan was ordered for 28 patients (66.7%), leading to diagnosis confirmation in 17 patients and change in management plan in 11 patients. [GRC3] Groups 1 and 2 consisted of 17 and 25 patients, respectively. For mid to long-term functional outcomes, there were 14 and 10 patients in groups 1 and 2, respectively. Statistical analysis revealed no significant differences in the functional outcomes, pain scores, or satisfaction between groups. No infections, non-unions, physeal arrest, or post-operative ankle deformities were reported. Two (4.8%) patients had difficulty returning to sports post-surgery due to pain. One was a dancer, and the other patient had pain while running, which led to hardware removal. Both patients had parallel fixation. Hardware removal for groups 1 and 2 were 4 (23.5%) and 5 (20.0%) patients, respectively. The reasons for removal was pain in 2 patients, and parental preference in the remaining. CONCLUSIONThis is the largest reported series of pediatric patients with Tillaux fractures comparing functional outcomes of different methods of screw fixation orientation to the physis, which showed no difference regarding functional outcomes.

Consider Emergency Department Stress Examinations on Lateral Compression Type-1 Pelvic Ring Injuries with Complete Sacral Fractures: Commentary on an article by Graham J. DeKeyser, MD, et al.: "Emergency Department Stress Radiographs of Lateral Compression Type-1 Pelvic Ring Injuries Are Safe, Effective, and Reliable".

Commentary A minimally displaced Young and Burgess lateral compression type-1 (LC1) pelvic fracture represents a spectrum of injury1, and treatment is controversial. Sembler Soles et al. promoted nonoperative treatment for all2, but others such as Sagi et al. have shown that some of these LC1 fractures may benefit from a surgical procedure despite their benign radiographic appearance3. This led Sagi et al. to publish their technique for examination under anesthesia (EUA) of these fractures to identify occult instability that is missed by static radiographic imaging3. However, there is concern about the unnecessary anesthetic and operative cost for fractures that are determined to be stable in the operating room (OR). Furthermore, as surgeons, we may be biased and may be more likely to fix the fractures in patients who go to the OR for an additional stress examination despite initial borderline stress examination findings. Other authors have investigated a stress examination without anesthesia. Parry et al. performed an anteroposterior pelvic radiographic examination with the patient lying on the injured side while awake in the OR prior to EUA in 20 patients and found this to reliably identify pelvic instability4. However, I have not adopted this into my practice outside the OR because of the concern for patient tolerance in the emergency room and the fact that an anteroposterior pelvic radiograph is not as sensitive as an inlet view to identify rotational displacement. In their study, DeKeyser et al. wanted to investigate if the stress examination could be performed outside the operating room with the patient awake. They present a commonsense approach to see if a rotational stress examination of an LC1 fracture in the emergency department (ED) can reliably be performed, can be tolerated by the patient, and can be trusted to direct treatment. There are 2 important things to remember about the study methods as surgeons consider adopting this protocol in their practice. First, only isolated LC1 fractures (anterior pelvic ring disruption with an ipsilateral compression sacral fracture) with <10-mm displacement on static imaging were included. Second, the rotational stress examination protocol was very specific, including how to account for magnification when measuring displacement. For those patients who had a positive stress examination and went to the OR, the rotational stress examination was repeated under anesthesia for comparison with the ED stress examination. The findings of this article are very enlightening and can help surgeons to avoid taking specific types of patients with an LC1 fracture to the operating room to perform a stress examination. All 70 patients who were enrolled tolerated the stress examination in the radiographic suite without complication. An important correlation was identified between the mechanism of injury and the rate of positive stress examination. Fifty-four percent of the patients enrolled sustained the pelvic fracture from a high-energy mechanism. As expected, high-energy fractures were significantly more likely to have positive ED stress examinations. Two (4%) of the patients who had a negative stress examination in the ED converted to the operative group because of an inability to walk after the initial stress examination. Of note, they had high-energy mechanisms of injury and bilateral fractures of the rami, but still had a negative intraoperative EUA. Both were able to mobilize after the surgical procedure. Forty-three of the patients who had a negative ED stress examination had clinical and radiographic healing with no further radiographic displacement at the 3-month follow-up, which is consistent with the findings by Whiting et al.5, and patients with a positive ED stress examination had a similar amount of displacement during the intraoperative comparison stress examination. No occult LC3 injuries were identified. Risk factors that were identified for a positive stress examination include a high-energy mechanism of injury, a complete sacral fracture, and bilateral, parasymphyseal, and comminuted rami fractures. Finally, DeKeyser et al. draw some important conclusions. First, the ED stress examination should only be considered for patients with LC1 injuries secondary to high-energy mechanisms with complete sacral fractures. Second, patients with low-energy, incomplete sacral fractures should be allowed to mobilize prior to considering a stress examination. Third, none of the positive stress examinations included instability with an external rotation stress; therefore, the external stress examination is likely unnecessary. In my practice, I already follow the nonoperative protocol for low-energy, incomplete sacral fractures, but I do plan on incorporating the ED internal rotation stress examination for minimally displaced (<10 mm of displacement) LC1 fractures involving a high-energy mechanism and a complete sacral fracture.

The Effect of Aggregate Size and Resin Fraction on The Damping Capacity of Epoxy-Marble Composite

The production of material with high precission and high complexity has been rapidly increasing in several industrial sector. The high accuracy is difficult to achieve during manufacturing due to vibration factors that influenced the final product of material. In this study the relationship between particle size and percentage of marble aggregate with epoxy resin on damping capacity was studied systematically. The Composite materials were fabricated by using conventional casting technique with 10, 25, and 50% volume fraction of resin and two marble aggregate groups with 0.5-0.7 mm and 1.4-2.0 mm in particle size. The casting process was using multilayer pouring technologies to prevent void formation. 10% epoxy resin-fine marble aggregate has very good vibration result with 0.003 mm in displacement, 0.23 mm/s in velocity, and 0.2 m/s2 in acceleration. The 10% epoxy resin-fine marble aggregate also has the best damping ratio among the composite due to the large specific area and porosity inside the marble material with value of 0.5%. The multilayer pour techniques for composite has been successfully adapted in this study to minimalize void/bubble formation inside and upperside of epoxy resin during the fabrication of composite. The secondary electron image of composite was observed that the marble aggregates and epoxy resin bonding are very good and no crack or void formation in the interface of the marble aggregate and epoxy resin.

Unstable minimally displaced lateral compression type 1 (LC1) pelvic ring injuries have a similar hospital course as intertrochanteric femur fractures

IntroductionThe purpose of this study was to evaluate how the hospital course of minimally displaced LC1 fractures, with and without occult instability, compares with that of intertrochanteric femur fractures. Patients and MethodsRetrospective comparative cohort analysis at an urban level one trauma center of 40 consecutive patients with an isolated LC1 pelvic ring injury and 40 age/sex matched patients with an isolated intertrochanteric femur fracture was performed. Medical records and radiographs were reviewed for patient and injury characteristics, including demographics, displacement, time to surgery, ambulation, physical therapy (PT) clearance, hospital length of stay (LOS), and inpatient morphine milligram equivalents (MME). ResultsThe LC1 pelvic ring injury group included 26 (65%) patients with ≥ 10 mm of displacement on lateral stress radiographs. The unstable LC1 group, compared to the stable LC1 group, had a greater LOS (median difference (MD): 2 days, 95% confidence interval (CI): 1 to 4, p = 0.0004), longer time to ambulate 15 feet (MD: 1 day, CI: 1 to 2, p = 0.0002), longer time to clear PT (MD: 2 days, CI: 1 to 3, p = 0.0003), and more inpatient MMEs (MD: 386 MME, CI: 225.8 to 546.7, p = 0.0002). The unstable LC1 and intertrochanteric fracture groups had no detectable differences in LOS (p = 0.24), days to ambulate 15 feet (p = 0.46), days to clear PT (p = 0.95), and inpatient MMEs (p = 0.06). ConclusionPatients with minimally displaced unstable LC1 injuries had worse hospital courses than stable LC1 injuries and similar hospital courses as intertrochanteric femur fractures. These findings emphasize the associated morbidity of unstable LC1 injuries. Level of evidence: Level III, Retrospective cohort study

A Prospective Clinical Trial Comparing Surgical Fixation Versus Nonoperative Management of Minimally Displaced Complete Lateral Compression Pelvis Fractures.

To compare the early pain and functional outcomes of operative fixation versus nonoperative management for minimally displaced complete lateral compression (LC; OTA/AO 61-B1/B2) pelvic fractures. Prospective clinical trial. Two academic trauma centers. Forty-eight adult patients with LC pelvic ring injuries with <10 mm of displacement were treated nonoperatively and 47 with surgical fixation. Sixty percent of participants were randomized. Seventy-three percent of the fractures were displaced <5 mm, and 71% were LC-1 patterns. Operative fixation versus nonoperative management. The primary outcome was patient-reported pain using the 10-point Brief Pain Inventory. Functional outcome was measured using the Majeed pelvic score. Outcomes were analyzed using hierarchical Bayesian models to compare the average treatment effect from injury to 12 and 52 weeks postinjury. The probability of the mean treatment benefit exceeding a clinically important difference was determined. The 3-month average treatment effect of surgery compared with nonoperative management was a 1.2-point reduction in pain [95% credible interval (CrI): 0.4-1.9] and an 8% absolute improvement in the Majeed score (95% CrI: 3%-14%). Similar results persisted to 1 year. Patients with initial fracture displacement ≥5 mm experienced a larger reduction in pain (2.2, 95% CrI: 0.9-3.5) compared with those patients with less initial displacement (0.9, 95% CrI: 0.1-1.8). On average, surgical fixation likely provides a small improvement in pain and functional outcome for up to 12 months. Patients with ≥5 mm of posterior pelvic ring displacement are more likely to experience clinically important improvements in pain. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

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

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.

Ex vivo comparison of lateral plate repairs of experimental oblique ilial fractures in cats.

To determine the biomechanical behavior of different plate systems used for oblique ilial fracture fixation in cats. Ex vivo biomechanical study. Fifty fresh-frozen feline hemipelvises. Standardized simple oblique ilial fractures were created and fixed via lateral plating, using different implant systems (10 fractures in each group) The systems were: (1) the Advanced Locking Plate System (ALPS-5); (2) the Advanced Locking Plate System (ALPS-6.5); (3) the Locking Compression Plate 2.0 (LCP); (4) the FIXIN 1.9-2.5 Series (FIXIN), and (5) the Dynamic Compression Plate 2.0 (DCP). Stepwise sinusoidal cyclic loading was applied until failure (10-mm displacement). The groups were compared with regard to construct stiffness and the number of cycles withstood before 1-, 2-, 5-, and 10-mm displacement. Bending stiffness was lower in ALPS-5 than in other specimens (P < .05). The ALPS-6.5 specimens withstood more cycles (P < .05) before 2-, 5-, and 10-mm displacement than the ALPS-5 and DCP specimens . The LCP and FIXIN specimens endured more cycles than DCP specimens before displaying 5- and 10-mm displacement (P < .05). The ALPS-6.5, FIXIN, and LCP specimens endured higher loads before failure than the DCP specimens (P < .05). Screw loosening occurred in all nonlocking specimens, and bone slicing occurred in all locking specimens. The DCP and ALPS-5 constructs are less resistant to cyclic loading. Failure in nonlocking specimens involved screw loosening. It involved bone slicing in locking specimens. Both the plate size and the plate-screw interface are key to lateral plating success in cases of feline ilial fractures. The use of locking plates reduces the risk of the screw loosening in such cases.

Are Suture Tape Knots as Secure as Standard Suture? A Biomechanical Study.

Background:Few studies have investigated the biomechanical performance of flat-braided suture tapes versus round-braided sutures after being knotted.Purpose:To compare the loop security and knot strength of a standard round-braided suture with 3 commercially available flat-braided suture tapes using 2 types of arthroscopic knots.Study Design:Controlled laboratory study.Methods:One standard suture (SS) and 3 suture tapes (T1, T2, and T3) were tied with the surgeon’s knot (SK) and the Tennessee slider (TS), 25 times each, by a single surgeon. Each combination of knots and sutures underwent a preload, cyclic loading, and load to failure. Outcomes were loop security (defined by loop stretch after a 5-N preload), load at clinical failure (3 mm of displacement), and load at ultimate failure (suture rupture or knot slippage). Two-way analysis of variance was used for analysis.Results:Overall, the SK group had greater overall loop security than that of the TS group (0.4 ± 0.3 vs 0.5 ± 0.3 mm of stretch, respectively; P = .020). The clinical failure load varied by suture type (P < .001) but not knot type (P = .106). For both knot types, the SS had the lowest mean ± SD clinical failure load (SK, 171 ± 49 N; TS, 176 ± 37 N), which was significantly less than that of T2 (247 ± 85 N; P < .001) and T3 (251 ± 96 N; P < .001) for the SK type and T2 (231 ± 67 N; P = .023) for the TS type. T2 sutures had the greatest ultimate failure load for both knot types (SK, 418 ± 45 N; TS, 461 ± 57 N), which was significantly greater than SS, T1, and T3 (P < .001 for all). The TS knot had greater overall ultimate failure load than the SK (375 ± 64 vs 350 ± 66 N; P < .001).Conclusion:Not all suture tape knots had the same biomechanical properties, although knot security and strength appeared to be adequate for all suture tapes as well as for SS. There was no evidence that suture tape knots are lower profile than SS knots.Clinical Relevance:Surgeons should not use suture tape based only on the assumption that it has superior biomechanical properties to a standard round-braided suture.

Medial Epicondyle Apophyseal Avulsion Fractures in Youth Throwers: A Severe Variant of Little League Elbow (132)

Objectives:Medial epicondyle apophyseal avulsion fractures sustained during throwing represent an understudied, severe variant of medial epicondyle apophysitis, or ‘Little League elbow’. The current study sought to characterize presenting features, treatment options, and clinical results of a large cohort of pre-adolescent and adolescent patients who presented with these fractures.Methods:Skeletally immature athletes with medial epicondyle apophyseal avulsion fractures sustained during throwing from 2003-2017 at a tertiary-care pediatric referral center were identified. Exclusion criteria were fractures sustained during non-throwing activity or prior elbow fracture. Medical records and radiographic images were reviewed for study variables. Treatment decisions were made independently by fellowship-trained pediatric orthopaedic surgeons or sports medicine physicians on a case-by-case basis. Patients treated with open reduction and internal fixation (ORIF) were compared to those treated non-operatively, and all fracture patients were compared to a larger control group of patients diagnosed with medial epicondyle apophysitis/Little League elbow with no fracture.Results:During the study period, a total of 317 patients were diagnosed with Little League elbow due to medial epicondyle apophyseal overuse injury, 50 of whom (16%) sustained a discreet, radiographically confirmed epicondyle fracture sustained during a single throw. Median age of the fracture cohort at presentation was 13.1 years (range 8 years – 16 years). Forty-nine fracture patients (98%) were male baseball pitchers and one (2%) was a male football quarterback. Fracture patients had significantly higher median BMI (21.3 kg/m2 vs. 19.2kg/m2, p=0.004) than the apophysitis control group, but there was no significant difference in age. Of the 37 patients with documentation regarding pre-injury symptoms, 31 patients (84%) described pre-existing medical elbow pain prior to their acute injury, while 6 (16%) denied pain prior to the inciting throw. Of the 12 patients (24%) with documented shoulder exams at presentation, 5 (42%) demonstrated glenohumeral internal rotation deficit (GIRD). Twenty-three patients (46%) were treated with ORIF (22 single screw fixation; 1 suture anchor fixation), while 27 (54%) were treated non-operatively. Median fracture displacement was significantly greater in operative patients than non-operative patients (5.0mm vs. 3.0mm, p=<.001), with all ‘minimally displaced’ (<4mm) fractures undergoing non-operative treatment (Figure 1). Multivariable analysis determined that for each additional mm of displacement, the odds of surgical intervention increased by 6.4 times (OR=6.36; 95% CI=1.83-22.07; p=.004), when controlling for age and BMI. All patients returned to their throwing sport (RTS) at a median of 12.8 weeks post-diagnosis, but 13 (26%) developed recurrent elbow pain, with no significant difference in in RTS time or recurrence rate between treatment cohorts. Nine of twenty-two (41%) screw ORIF patients underwent secondary implant removal, with no significant difference in this rate between those with or without a washer.Conclusions:Medial epicondyle apophyseal avulsion fractures in youth throwers represent a severe variant of Little League elbow, constituting approximately 16% of cases within the condition’s spectrum. These fractures may be effectively treated with either non-operative measures, particularly minimally displaced fractures <4mm, or ORIF, though >40% of operative patients may require implant removal. A large majority of patients reported medial elbow pain prior to fracture, suggesting this severe presentation of Little League elbow may be preventable.

Mechanical Comparison of High-Strength Tape Suture Versus High-Strength Round Suture

PurposeTo compare knot and loop characteristics of commonly used high-strength tapes and high-strength round sutures.MethodsTwenty tied 30-mm loops were prepared for using suture-knot combinations of 4 common arthroscopic knots or a hand-tied surgeon’s knot and 7 sutures. Two tapes (BroadBand, SutureTape) and three no. 2 sutures (MaxBraid, FiberWire, DynaCord) were compared. Two additional larger tape sutures (FiberTape, PermaTape) not commonly tied arthroscopically were included in the hand-tied group. Each suture-knot combination was evaluated for loop integrity (single load to a specified elongation), knot security (plastic loop deformation with cyclic testing), loop security, and knot volume. Data were compared using analysis of variance followed by Tukey-Kramer post hoc tests.ResultsBroadBand and SutureTape demonstrated superior loop integrity compared to most no. 2 suture-knot combinations. FiberTape (430.48 ± 89.00 N) and PermaTape (545.16 ± 95.09 N) required significantly greater force to undergo 3 mm of displacement than all other hand-tied sutures (P < .001). All suture-knot configurations demonstrated significant plastic deformation (cyclic elongation) over 1000 cycles (P < 0.001). DynaCord displayed the best loop security except when paired with the Duncan loop. Overall, BroadBand and SutureTape had lower knot volumes compared to all other sutures.ConclusionThis study exhibits the ability of narrow tape sutures to provide reliable tissue apposition and fixation in multiple suture-knot configurations, while decreasing the potential adverse effects accompanying knot prominence. Generally, BroadBand and SutureTape demonstrated an ideal balance of mechanical characteristics to achieve the optimal suture-knot construct among those tested. Dynacord displayed superior loop security and performed best among round sutures. PermaTape and FiberTape showed greater loop integrity, albeit to the detriment of loop security and knot volume.Clinical RelevanceWhen securing a rotator cuff repair construct with a knot, one should have a basic understanding of the mechanical properties of the suture and knot being used to provide the best possible repair. This study will provide information about the mechanical characteristics of commonly used high-strength tape suture knots and loops to help determine what knot type may provide the best overall construct.

Tibial alignment following intramedullary nailing via three approaches.

The purpose of this study is to evaluate the incidence of malalignment in patients undergoing IMN for tibial shaft fractures treated with the extra-articular lateral parapatellar, suprapatellar, and infrapatellar approaches. A retrospective review of an institutional trauma database was completed at a single level 1 trauma academic medical centre. Quality of reduction was assessed using the following three parameters: (1) < 10°of angulation in orthogonal radiographic views (2) < 5mm of displacement between the major fracture fragments (3) < 5mm of gap between the major fracture fragments. A good reduction was one that met all 3 criteria, an acceptable reduction met 2 criteria, and a bad reduction met one or none of the criteria. All patients treated consecutively for tibial shaft fractures between June 1, 2019 and June 1, 2020 were identified. The final cohort included 57 tibia fractures in 56 patients. Of the 57 tibia fractures, 8 (14%) were proximal third, 32 (56%) were middle third, and 17 (30%) were distal third fractures. We found no significant difference in angulation, displacement, or gapping with respect to surgical approach utilized or location of fracture (proximal or distal tibia fractures) on one-way ANOVA. Quality of reduction was rated as "good" in 48 (84%) of the cases (19 supra, 13 infra, and 16 lateral). Nine reductions (16%) met only two of the three reduction quality criteria and were considered acceptable reductions. These included 2 suprapatellar (1 > 5mm displacement, 1 > 5mm gapping), 4 infrapatellar (4 > 5mm displacement), and 3 lateral extra-articular parapatellar (2 > 5mm displacement and 1 > 5mm gapping). No reductions were determined to be bad according the Baumgaertner et al. criteria. There was no significant difference in the rate of combined fibula fractures or the rate of fibular fixation between the three cohorts. In conclusion, no significant difference was found in fracture reduction angulation, displacement, and gapping in patients treated with an IMN with respect to approach for diaphyseal or metadiaphyseal tibial shaft fractures.

Pullout Strength of All-Suture and Metallic Anchors in Repair of Lateral Collateral Ligament Injuries of the Elbow

To compare the biomechanical properties of metallic anchor (MA) and all-suture anchor (ASA) constructs in the anatomic reattachment of the lateral ulnar collateral ligament complex to its humeral insertion. Twenty paired male human cadaveric elbows with a mean age of 46.3 years (range: 33-58 years) were used in this study. Each pair was randomly allocated across 2 groups of either MA or ASA. A single 3.5-mm MA or 2.6-mm ASA was then inserted flush into the lateral epicondyle. A dynamic tensile testing machine was used to perform cyclic loading followed by a load to failure test. During the cyclic loading phase, the anchors were sinusoidally tensioned from 10 N to 100 N for 1,000 cycles at a frequency of 0.5 Hz. In the load to failure test, the anchors were pulled at a rate of 3 mm/s. Load at 1-mm and 2-mm displacement, as well as load to ultimate failure were assessed. Clinical failure was defined as displacement of more than 2 mm. Normality of data was assessed with the Shapiro-Wilk test. Continuous data are presented as medians and compared with the Mann-Whitney U test and categorical data was compared with the χ2 test or Fisher exact test. Displacement was significantly greater for the ASA group during cyclic loading starting from the tenth cycle (P < .05). Displacement of more than 5 mm within the first 100 cycles was observed in 2 anchors in the ASA group. No difference was observed in loads required to displace 1 mm (MA: 146 N [6-169] vs ASA: 144 N [2-153]; P= .53) and 2 mm (MA: 171 N [13-202] vs ASA: 161 N [9-191]; P= .97), but there was a statistically significant difference between ultimate loads in favor of ASA in the load to failure test (MA: 297 N [84-343] vs 463 N [176-620]; P < .01). In the cyclic test, no difference in clinical failure defined as pull-out of more than 2 mm was observed between 3.5 mm MAs and 2.6 mm ASAs. In the ultimate load to failure analysis, no difference was observed between groups in force causing 1 and 2 mm of displacement, but there was a significant difference in favor of ASA in the pull to ultimate failure test. Potential benefits of all-suture anchors include preservation of bone stock, reduced radiographic artifacts, and easier revisions. Although their use has been investigated thoroughly in the shoulder, there remains a paucity of literature regarding displacement and pull-out strength in the elbow.

High-Strength Suture Tapes Are Biomechanically Stronger Than High-Strength Sutures Used in Rotator Cuff Repair

PurposeTo assess the mechanical properties, tendon resistance to suture cutout, and knot size of a broad variety of high-strength sutures and tapes available for arthroscopic rotator cuff repair.MethodsNine different types of high-strength sutures and tapes for arthroscopic rotator cuff repair were studied: 6 were tapes (FiberTape, Hi-Fi Tape, Permatape, SutureTape, UltraTape, and XBraid TT), and 3 were sutures (Dynacord, FiberWire, and Ultrabraid). First, mechanical tensile testing of suture loops (n = 6) was performed. Second, the suture material was passed through an intact human cadaveric rotator cuff tendon (supraspinatus or infraspinatus), and cyclic as well as load-to-failure testing was performed, 8 times for each suture or tape. Statistical analysis of groups (tapes vs sutures) and between each suture and each tape was performed.ResultsMaterial testing revealed significant differences with superior mechanical properties of tapes compared with sutures regarding load for 3 mm of displacement (201 N vs 84 N, P < .0001), displacement at 200 N (3.6 mm vs 6.6 mm, P < .0001), stiffness (46 N/mm vs 25 N/mm, P < .0001), and ultimate load to failure (509 N vs 288 N, P < .0001). FiberTape showed the highest ultimate load to failure (805.5 ± 36.1 N), the highest load necessary for 3 mm of displacement (376.2 ± 19.1 N), and the lowest displacement at a 200-N load (2 ± 0.1 mm). Permatape had the highest stiffness (58.5 ± 5.3 N/mm). FiberTape had the highest knot height (9.5 ± 1.3 mm) and knot width (3.8 ± 0.7 mm) of a suture loop with 7 square knots. The typical failure mode in the cadaveric study part was tendon cut through.ConclusionsBiomechanical in vitro testing showed that high-strength suture tapes compared with regular high-strength sutures have significantly better mechanical properties in both dry-laboratory testing and human cadaveric rotator cuff tendon pullout testing. FiberTape outperformed the other tapes and the sutures used in this analysis. Nonetheless, differences in tendon testing appeared to be less substantial than in dry-laboratory testing, and FiberTape had the highest knot height and width.Clinical RelevanceFiberTape revealed the most favorable biomechanical performance in dry-laboratory and rotator cuff tendon testing. It may provide the best repair strength in vivo; however, it also has the largest knot size.

Knotless Suture Anchors: A Comparative Biomechanical Study of Acetabular Rim Anchor Fixation with Implications for Hip Labral Repair

AbstractThe purpose of this study was to analyze relevant initial-implantation biomechanical properties of five knotless suture anchors available for use in acetabular labral repair. Five knotless suture anchor constructs were tested: Arthrex PushLock 2.9, Arthrex PushLock 2.4, Arthrex SutureTak 3.0, Stryker CinchLock SS 2.4, and Stryker CinchLock Flex 2.4. Anchors were placed in synthetic bone blocks and in acetabular bone of cadaveric specimens. Constructs were subjected to cyclic and load-to-failure (LTF) testing. Displacement at 1, 100, 250, and 500 cycles, yield load, ultimate load, and failure mode were compared with statistically significant (p &lt; 0.005) differences. PushLock 2.9 mm and CinchLock SS 2.4 anchor constructs had significantly less displacement than PushLock 2.4 mm after 1 cycle (p = 0.017) and 500 cycles (p = 0.043). Excluding “tare” displacement after the first cycle, all anchor constructs were associated with less than 2.0 mm of displacement after 500 cycles. Arthrex PushLock 2.4 and SutureTak 3.0 had the highest number of failures prior to completing cyclic loading. Arthrex PushLock 2.9 was associated with the highest LTF in cadaver (p = 0.00013) and synthetic (p = 0.009) bone models. Most common failure mode in cadaver bone was eyelet failure for all anchor types. Knotless suture anchors used for arthroscopic hip surgery (2.9 mm PushLock, 2.4 mm PushLock, 3.0 mm SutureTak, 2.4 mm CinchLock SS, and 2.4 mm CinchLock Flex) were associated with material properties that met or exceeded the reported thresholds for successful periarticular soft tissue repair surgeries. Based on cyclic and LTF testing in synthetic bone blocks and cadaveric acetabulums, 2.9 mm PushLocks and 2.4 mm CinchLock SS anchors may have potential biomechanical advantages over the other constructs tested. Further functional ex vivo and preclinical animal model studies are recommended to further characterize suture anchor constructs designed for acetabular labrum repair. These results provide novel and relevant biomechanical testing data that contribute to assessing knotless suture anchor constructs for use in acetabular labral repair.

Topological Optimization of Brake Pedal for Metal Additive Manufacturing: A Case Study

Additive Manufacturing (AM) has become popular for rapid prototyping and it is presently widely used in different branches of industry because of its advantages such as freedom of design, mass customization, waste minimization and the ability to manufacture complex shape. AM is the process of making 3D object from computer model data by depositing of material layer by layer. Topology optimization is iterative modifying the shape and optimizing material within a given designs space for load, boundary condition thus leading to weight reduction of components. Thus, to form lightweight components which have great advantage where energy consumption is minimal, topology optimization is used. Reducing weight and decreasing the material usage while keeping the product functions are the main challenges. Studies on the integration of the topology optimization and additive manufacturing, specifically mass reduction attract considerable attention. The topology optimization process is employed in this case study, to redesign a lightweight automotive brake pedal to show the potential of topology optimized design for additive manufacturing. As a result of this study 54.07% weight reduction was achieved in the total mass. The thermo- mechanical analysis for additive manufacturing showed that the part without topological optimization 108 MPa of stress and 1,099 mm of displacement were obtained and after optimization they were 196,1 MPa and 1,295 mm, respectively.

Design and Calibration of a Hall Effect System for Measurement of Six-Degree-of-Freedom Motion within a Stacked Column.

This paper presents the design, development and evaluation of a unique non-contact instrumentation system that can accurately measure the interface displacement between two rigid components in six degrees of freedom. The system was developed to allow measurement of the relative displacements between interfaces within a stacked column of brick-like components, with an accuracy of 0.05 mm and 0.1 degrees. The columns comprised up to 14 components, with each component being a scale model of a graphite brick within an Advanced Gas-cooled Reactor core. A set of 585 of these columns makes up the Multi Layer Array, which was designed to investigate the response of the reactor core to seismic inputs, with excitation levels up to 1 g from 0 to 100 Hz. The nature of the application required a compact and robust design capable of accurately recording fully coupled motion in all six degrees of freedom during dynamic testing. The novel design implemented 12 Hall effect sensors with a calibration procedure based on system identification techniques. The measurement uncertainty was ±0.050 mm for displacement and ±0.052 degrees for rotation, and the system can tolerate loss of data from two sensors with the uncertainly increasing to only 0.061 mm in translation and 0.088 degrees in rotation. The system has been deployed in a research programme that has enabled EDF to present seismic safety cases to the Office for Nuclear Regulation, resulting in life extension approvals for several reactors. The measurement system developed could be readily applied to other situations where the imposed level of stress at the interface causes negligible material strain, and accurate non-contact six-degree-of-freedom interface measurement is required.

Understanding TAVR device expansion as it relates to morphology of the bicuspid aortic valve: A simulation study.

The bicuspid aortic valve (BAV) is a common and heterogeneous congenital heart abnormality that is often complicated by aortic stenosis. Although initially developed for tricuspid aortic valves (TAV), transcatheter aortic valve replacement (TAVR) devices are increasingly applied to the treatment of BAV stenosis. It is known that patient-device relationship between TAVR and BAV are not equivalent to those observed in TAV but the nature of these differences are not well understood. We sought to better understand the patient-device relationships between TAVR devices and the two most common morphologies of BAV. We performed finite element simulation of TAVR deployment into three cases of idealized aortic anatomies (TAV, Sievers 0 BAV, Sievers 1 BAV), derived from patient-specific measurements. Valve leaflet von Mises stress at the aortic commissures differed by valve configuration over a ten-fold range (TAV: 0.55 MPa, Sievers 0: 6.64 MPa, and Sievers 1: 4.19 MPa). First principle stress on the aortic wall was greater in Sievers 1 (0.316 MPa) and Sievers 0 BAV (0.137 MPa) compared to TAV (0.056 MPa). TAVR placement in Sievers 1 BAV demonstrated significant device asymmetric alignment, with 1.09 mm of displacement between the center of the device measured at the annulus and at the leaflet free edge. This orifice displacement was marginal in TAV (0.33 mm) and even lower in Sievers 0 BAV (0.23 mm). BAV TAVR, depending on the subtype involved, may encounter disparate combinations of device under expansion and asymmetry compared to TAV deployment. Understanding the impacts of BAV morphology on patient-device relationships can help improve device selection, patient eligibility, and the overall safety of TAVR in BAV.

The Effect of Rim Preparation, Labral Augmentation, and Labral Reconstruction on the Suction Seal of the Hip

To evaluate the biomechanical properties of the labral suction seal in the native labrum and after rim preparation, labral augmentation, and labral reconstruction. Eight hemi-pelvises were dissected to the level of labrum and mounted for biomechanical testing. Each specimen was tested in axial distraction starting with the native labrum and then sequentially following rim preparation from 12 to 3 o'clock, labral augmentation, and segmental labral reconstruction using the iliotibial band allograft. In each condition, the specimens were compressed to 250 N and then distracted at 10 mm/s with force and displacement continuously recorded. Each test was repeated 3 times, and the mean peak force, displacement at peak force, and work were calculated. Data were reported as a percentage of the intact values to account for sex and size differences. Statistical testing was performed via a repeated-measures analysis of variance with a post hoc Tukey analysis. Peak loads occurred within 2.21 to 3.11 mm of displacement. The mean peak force, displacement at peak force, and work relative to the intact condition were the following: rim preparation (91.1% ± 8.5%, 94.4% ± 14.3%, 93.4% ± 23.5%, respectively), augmentation (66.1% ± 27.6%, 78.2% ± 16.3%, 55.7% ± 30.7%, respectively), and reconstruction (55.6% ± 25.7%, 64.7% ± 31.4%, 38.7% ± 27.2%, respectively). There was no significant difference in peak force following the rim preparation (P= .807), but peak force was significantly decreased after augmentation and reconstruction (P= .010 and P < .001, respectively). There was no significant difference in displacement at peak force following rim preparation or augmentation (P= .936 and P= .125, respectively), but displacement at peak force was significantly decreased after reconstruction (P= .005). The work from the suction seal was significantly less in both augmentation and reconstruction states compared to the intact labrum (P= .004 and P < .001, respectively) and rim preparation (P= .017 and P < .001, respectively). The results show that the suction seal is not significantly changed following rim preparation. Relative to the rim preparation, labral augmentation may re-create the labral suction seal better than labral reconstruction. This study provides a biomechanical basis for surgical decision making and clinical management of patients with labral tears of the hip.