Influence of the Advanced One-Step Mixing System Under Non-Vacuum on the Mechanical Properties of Acrylic Bone Cement.

Background: The specific aim of this study was to evaluate the mechanical properties of cement prepared with the advanced one-step mixing system and whether the addition of vacuum conditions yielded an appreciable improvement in the biomechanical strength or overall quality of bone cement. Methods: The advanced one-step mixing system was used. Twelve specimens were prepared by mixing under vacuum conditions and 12 specimens were prepared by mixing without a vacuum. Radiographs of cement specimens were analyzed to determine the porosity of the test region. Tensile testing of the specimens was performed with a loading rate of 2.54mm/min at room temperature. The ultimate tensile strength (UTS) and the tensile elastic modulus (E) were determined for each sample. Results: The UTS of the bone cement samples mixed under vacuum conditions were not significantly different than those mixed without vacuum (vacuum: 39±6MPa; non-vacuum: 35±6MPa; p=0.637). The E of samples mixed under vacuum conditions was significantly higher than the bone cement mixed without vacuum (vacuum: 2.78±0.06GPa; non-vacuum: 2.63±0.15GPa; p=0.019). Radiographic images showed samples mixed under vacuum conditions contained fewer defects than the samples mixed without vacuum (vacuum: 3.5%±3.3% (range: 0.0%-9.0%); non-vacuum: 6.9%±1.0% (range: 4.6%-8.2%)). Conclusion: Mixing bone cement with the advanced one-step mixing system under vacuum conditions does not produce an appreciable difference in the UTS of the bone cement in a bench biomechanical testing model compared to the bone cement mixed without vacuum. It does, however, create a less porous cement mixture with a higher E compared to cement mixed without vacuum. Level of Evidence: V.

Center-Center Surgical Technique With Dynamic Syndesmosis Fixation: A Cadaveric Pilot Study.

The objective of this cadaveric biomechanical study was to evaluate if the center-center surgical technique is a reliable and repeatable method of achieving proper syndesmotic reduction when using dynamic syndesmotic fixation. Nine fresh frozen above-knee cadaveric lower extremities were used. Computerized tomography (CT) scans were first obtained for each intact specimen as the baseline for comparison. A simulated complete syndesmotic disruption was created by transection of all deltoid and syndesmotic ligaments. Instability of the ankle was confirmed with stress imaging using fluoroscopy. Each unstable specimen was repaired using the center-center surgical technique with dynamic syndesmosis fixation. A series of measurements from the axial CT images of intact and repaired specimens were used to determine the anatomic distal tibiofibular relationships for comparison of changes from intact to postfixation. All radiographic measurements were performed by 4 independent foot and ankle surgeons. The level of inter-rater reliability for all the measurements was found to be "moderate" to "excellent" agreement (ICC value: 0.865-0.983, 95% confidence interval: 0.634-0.996). There was no statistical difference found between rotational alignment of native and postfixation (a/b: p = .843; b-a: p = .125; θ: p = .062). There was a statistical difference detected for lateral alignment at the center of fibularis incisura between native and postfixation (average: -0.6 ± 0.8 mm, range: -2.3 to 1.2 mm, p < .001). There was no statistical difference found for the anteroposterior translation alignment between native and postfixation (d/e: p = .251; f: p = .377). This study demonstrated the use of the center-center surgical technique as a viable and repeatable method for achieving anatomical reduction of the tibiofibular syndesmosis when used with dynamic fixation modalities.

Evaluation of Intramedullary Olecranon Screw Fixation for Simple Olecranon Fractures: A Biomechanical Study.

PURPOSE: The purpose of this study was to biomechanically evaluate the stability of the 6.5 mm intramedullary (IM) olecranon screw compared to locking compression plate fixation for Orthopedic Trauma Association/AO Foundation (OTA/AO) 2U1B1 olecranon fractures under cyclic range of motion of the elbow. METHODS: Twenty paired elbows were randomized to either IM olecranon screw or locking compression plate fixation of a simulated OTA/AO 2U1B1 fracture. Pullout strength was tested by increasing force applied to the triceps and proximal fragment. Fracture gap displacement was measured using differential variable reluctance transducers as the elbow was cycled through a 135° arc of motion using a servohydraulic testing system. RESULTS: Analysis of variance revealed significant interaction between group and load on fracture distraction after the 500th cycle in three settings: between the plate at 5-pound load and screw at 35-pound load, the screw at 5-pound load and screw at 35-pound load, and between the plate at 15-pound load and screw at 35-pound load. The difference in the rate of failure between plate (2 of 80 samples) and screw (4 of 80 samples) was not statistically significant. CONCLUSIONS: For OTA/AO 2U1B1 olecranon fractures, a single 6.5 mm IM olecranon screw demonstrated similar stability when compared to the locking compression plates throughout range of motion testing. CLINICAL RELEVANCE: From a biomechanical perspective, 6.5 mm IM screws and locking compression plates have similar ability to maintain fracture reduction following simulated elbow range of motion exercises in OTA/AO 2U1B1 fractures, giving surgeons another option in the management of these fractures.

Laparoscopic-Assisted Transversus Abdominis Plane Block Is Superior to Port Site Infiltration in Reducing Post-Operative Opioid Use in Laparoscopic Surgery.

BACKGROUND: The ultrasound-guided transversus abdominis plane (TAP) block can be time-consuming, costly, and technically challenging in the bariatric patient population. Laparoscopic-assisted TAP (L-TAP) block was developed and has been shown to be non-inferior to ultrasound-guided blocks. Postoperative pain can be significant, and pain control in the morbidly obese patients can be challenging. This study's aim was to compare L-TAP block to traditional port site infiltration in terms of postoperative opioid requirement for morbidly obese patients after laparoscopic Roux-en-Y gastric bypass (RYGB) surgery. METHODS: A retrospective chart review was performed from February 2019 through February 2020. Two study groups: L-TAP block and port site infiltration. Outcomes examined the amount of opioid used at different time segments relative to the operation. All intravenous (IV) and oral opioids used were converted into IV morphine milligram equivalents (MME) for standardization. RESULTS: 150 patients were included. The patient characteristics were not statistically significant between the two groups. Post-operative opioid use trended lower in the L-TAP block group in all time segments. A significant difference was detected in IV opioid use during post-operative day 0 with the mean MME for the L-TAP block group being 1.1±3.8 and port site infiltration group being 2.8±4.5 (P = .02). CONCLUSIONS: The L-TAP block more effectively reduces postoperative opioid use in comparison to port site infiltration in laparoscopic Roux-en-Y gastric bypass (RYGB) surgery. Based on these findings, as well as the efficiency and cost-effectiveness of L-TAP blocks, its routine use in laparoscopy should be considered.

Is Plain Anterior-Posterior Radiograph of the Pelvis Adequate for Assessment of Radiographic Implant Migration Evaluation in Total Hip Arthroplasty?

Introduction: A commonly utilized method of measuring femoral stem migration in total hip arthroplasty (THA) on plain anteroposterior (AP) pelvis radiograph with referenced image magnification has not been rigorously evaluated. This study aims to validate the reproducibility of the methods used in this technique. Methods: A retrospective study of the standardized AP pelvis radiographs of patients who had undergone THA utilizing a Corail® femoral stem was performed from June 2012 through December 2017. Radiological evaluation (head diameter, stem length, and stem seating length) were undertaken at three clinical follow-up times. Each radiographic measurement of each radiograph was repeated five times. Outcomes investigated included inter- and intra-radiograph reproducibility evaluation and radiographic image magnification. The stem length error and stem subsidence were also evaluated. Results: Two hundred THA patients met the inclusion/ exclusion criteria. The intra-radiograph reproducibility of the stem length and head diameter measurements have at least "good" reproducibility with repeated measurements falling within 0.5 mm for both measurements. The reliability for femoral stem seating length measurements has "questionable/poor" reproducibility. The inter-radiograph reproducibility was, however, substantially lower. High level of unreliable measurements with values less than 0.0 mm for both femoral stem length errors (55%) and femoral stem subsidence (32%) measurements. Less than 45% accuracy (femoral stem length error: 33%; femoral stem subsidence: 44%) to within 3 mm error. Conclusions: This study demonstrates that the assessment of radiographic implant migration after THA made on a sequence of plain AP pelvis radiograph have poor reproducibility.Level of Evidence: III.

A Biomechanical Comparison of Varying Base Knot Configurations with Different Overhand/Underhand Combinations of Reversing Half-Hitches on Alternating Posts After Basic Instructional Training.

Background: Constructing a durable arthroscopic knot is critical for secure tissue fixation. The effect of various arthroscopic base knot configurations paired with various overhand/underhand stacking combinations of three reversing half-hitches on alternating posts (RHAPs) on knot strength and integrity remains unanswered. Methods: Three common base knots (Surgeon's, Weston and, Tennessee Slider) followed by different overhand/underhand stacking combinations of three RHAPs were evaluated. Ten knots of each combination were tied by four subjects with varying levels of experience, resulting in the analysis of 480 total knots. A single load-to-failure test was performed to evaluate knot strength and integrity. The ultimate clinical failure load and mode of failure were recorded. Results: All knots created surpassed the estimated minimum required load per suture. There was, however, statistically large inter-subject variability for each base knot configuration. The Surgeon's base knot was found to vary the least in knot strength, while the Tennessee base knot was found to vary the most. Knot security was mostly influenced by the base knot configuration than the different overhand/underhand RHAP stacking combinations. Knot slippage failure mode was higher with knots tied with the Weston base knot compared to the other two configurations. Conclusions: Arthroscopic base knot configurations paired with different overhand/underhand stacking combinations of RHAPs yielded knot capable of secure tissue fixation. A short instructional training period appears to be sufficient for inexperienced individuals to learn easier base knot configurations, more challenging and complicated knots, however, may require training in a more gradual fashion. Clinical Relevance: The findings of this study provide information that the importance of hands-on experience for inexperienced individuals, such as residents, in performing arthroscopic knot tying, and that can lead to improving the securely constructed arthroscopic knots, which increase positive outcomes related to strengthened soft tissue to bone fixation of post-operative patients.Level of Evidence: V.

The Effect of Different Combinations of Three Stacked Half-Hitches and Suture Materials on an Arthroscopic Knot in a Dry or Wet Environment.

Purpose: Evidence is lacking on the effect of different combinations of three stacked half-hitches and suture materials on the loop/ knot security of an arthroscopic knot under cyclic loading conditions. The specific aim of this study was to identify variables, such as stacked half-hitch configurations, suture materials, and testing environments, that affect knot strength and loop security under cyclic loading conditions. Methods: Two suture materials (Orthocord and ForceFiber) were used to tie five differently stacked reversing half-hitches on alternating posts (RHAP) in an arthroscopic knot condition. All knots were evaluated in both dry and wet cyclic loading tests. Results: Knots tied with three identical half-hitches stacked on the same post (Conf #1) resulted in 100% knot slippage regardless of suture material in dry environment. In the wet environment this knot configuration performed slightly better (ForceFiber: 20% survived; Orthocord: 40% survived). With knots tied with one of the half-hitches in the RHAPs reversed, a significant improvement occurred in knot holding compared to Conf #1 (p<0.05). Knots tied with the last half-hitches in the RHAPs reversed using ForceFiber were 100% secure in both test environments; whereas those tied with Orthocord had 70% and 80% security rates in the respective environments. Knots tied with two half-hitches of the RHAPs reversed demonstrated the best overall performance. Conclusion: Significant effects for both stacked half-hitch configurations and suture materials on the knot loop and knot security were observed. Caution should be used when tying the 3 RHAPs in a knot using standard arthroscopic techniques. This study may provide a solution that might improve the maximum failure loads observed between orthopaedic surgeons, and achieve better clinical outcomes. Clinical Relevance: The findings of this study indicate the importance of three reversing half-hitches on alternating posts in performing arthroscopic knot tying, and provide evidence regarding discrepancies of maximum clinical failure loads observed between orthopaedic surgeons leading to better surgical outcomes.

Evaluating Different Clinical Diagnosis of Anterior Cruciate Ligament Ruptures In Providers with Different Training Backgrounds.

INTRODUCTION: Previous studies have shown that provider training and the tests performed play a role in the accuracy of diagnosis of anterior cruciate ligament (ACL) injuries. The specific aim of the current study is to determine the examiner proficiency and accuracy in performing the different proactive tests of ACL rupture before and after the induction of anesthesia prior to a definitive surgical procedure. MATERIALS AND METHODS: A case series was performed from January of 2015 through July of 2015. Two examiners were included (an experienced orthopaedic sports surgeon with more than 16 years in practice and an experienced orthopaedic physician assistant with 6 years of clinical experience in orthopaedic sports medicine). Three different physical examination tests were used before and after the induction of anesthesia to the patient: 1) Lachman test, 2) pivot shift test, and 3) Lelli test. Relevant patient demographic information such as BMI, thigh girth, and calf girth were recorded. Diagnosis of ACL rupture had been established pre-operatively. RESULTS: Thirty three patients met the inclusion criteria (males: 21 (64%), female: 12 (36%)). High percent of false negative was found with pivot shift test for both before and after anesthesia when compared to the other two tests. The Lelli test seemed to be most favorable to both the surgeon and the physician assistant with at least 67% favorable, while the pivot shift was least often felt to be the most useful test. No relationship was found for either patients' thigh or patients' calf girths with the physical examination test results for both examiners for any of the three tests (p = 0.110). CONCLUSION: The diagnostic accuracy and limitations of the various tests for ACL injury need to be understood. Clinically, it is recommended performing at least two different examinations, as each test has its own specific limitations. Level of Evidence: III- Prospective Cohort Study without blinding.

Strength of Resistance to "Flip" the Tightened Half-Hitches of an Arthroscopic Knot.

PURPOSE: The purpose of this study was to biomechanically determine the minimum strength required to "flip" a seated and tightened half-hitch in a knot of different braided polyblend sutures. METHODS: ForceFiber, FiberWire, Orthocord, and Ultrabraid were evaluated. All knot tying processes began by advancing an initial base knot down to a standardized rod. All half-hitches were tied using a single-hole knot pusher in a dry environment, and were tightened with 45N by using past-pointing maneuver. A tension was then deliberately applied to the wrapping suture limb until a "flip" occurred, and the amount of tension was measured by the load cell. Three trials for each half-hitch and 3 half-hitches for each arthroscopic knot with 12 knots of each material were tied. All respective tension loads were collected through the digital video recordings (knot closeup view and load cell reading). RESULTS: Orthocord was the easiest to "flip" a seated and tightened half-hitch (average: 10±3N), whereas Ultrabraid was hardest to "flip" (average: 23±7N). ForceFiber and FiberWire were about 49% and 15% more resistance to "flip" when compared to Orthocord. After each trial of flipping the half-hitch back and re-tightened, there was a significant reduction in strength required to "flip" the tightened half-hitch. CONCLUSION: 1) The unintentional minimum tensile strength greater than 10N applied to the wrapping suture limb on the seated and tightened half-hitch could potentially "flip" the half-hitch in a knot during arthroscopic procedures, and 2) different braided suture material has an affect on the tensile strength to "flip" a seated and tightened half-hitch in an arthroscopic knot. CLINICAL RELEVANCE: The findings of this study indicated that even a seated and tightened half-hitch in an arthroscopic knot could easily be "flipped" if an unintentional tension was applied to the wrapping suture limb, and thereby reduced the knot security strength. In addition different suture materials could have an effect on the strength needed to "flip" the tightened half-hitch.

Functional Outcomes of Thoracolumbar Junction Spine Fractures.

INTRODUCTION: Few studies have evaluated the functional outcomes of traumatic thoracic and lumbar vertebral body fractures. This study evaluated the functional and clinical outcomes of patients, who sustained a fracture to the thoracolumbar area of the spine (T10 to L2 region), with ≥ 25° kyphosis versus those with less kyphotic curvature. METHODS: The trauma registry records of two level 1 trauma centers using ICD-9 codes for fracture to the thoracolumbar juncture (T10 to L2 region) were reviewed. Kyphosis angle was measured on the standing lateral thoracolumbar (T1 - L5) radiograph at initial trauma and at clinical follow-up. Functional outcome questionnaires, including the Oswestry Disability Questionnaire (ODQ), the Roland Morris Disability Questionnaire (RMDQ), and the Nottingham Health Profile (NHP), were evaluated at clinical follow-up. Work status and medication used after trauma also were recorded. RESULTS: A total of 38 patients met the inclusive criteria. Seventeen patients (45%) had ≥ 25° kyphosis and 21 patients (55%) had < 25° kyphosis at follow-up. These two groups were similar based on sex and age. Based on the ODQ Score, the RMDQ Score, and the NHP, no statistically significant differences were detected between the two groups in regards to energy, pain, mobility, emotional reaction, social isolation, and sleep. CONCLUSIONS: Patients who sustained a fracture to the thoracolumbar area of the spine with ≥ 25° kyphosis do not report worse clinical outcomes. When using the kyphosis angle as an indication for surgery, it should be used with caution and not exclusively.

Validation of Different Combination of Three Reversing Half-Hitches Alternating Posts (RHAPs) Effects on Arthroscopic Knot Integrity.

INTRODUCTION: With arthroscopic techniques being used, the importance of knot tying has been examined. Previous literature has examined the use of reversing half-hitches on alternating posts (RHAPs) on knot security. Separately, there has been research regarding different suture materials commonly used in the operating room. The specific aim of this study was to validate the effect of different stacked half-hitch configuration and different braided suture materials on arthroscopic knot integrity. METHODS: Three different suture materials tied with five different RHAPs in arthroscopic knots were compared. A single load-to-failure test was performed and the mean ultimate clinical failure load was obtained. RESULTS: Significant knot holding strength improvement was found when one half-hitch was reversed as compared to baseline knot. When two of the half-hitches were reversed, there was a greater improvement with all knots having a mean ultimate clinical failure load greater than 150 newtons (N). Comparison of the suture materials demonstrated a higher mean ultimate clinical failure load when Force Fiber® was used and at least one half-hitch was reversed. Knots tied with either Force Fiber® or Orthocord® showed 0% chance of knot slippage while knots tied with FiberWire® or braided fishing line had about 10 and 30% knot slippage chances, respectively. CONCLUSIONS: A significant effect was observed in regards to both stacked half-hitch configuration and suture materials used on knot loop and knot security. Caution should be used with tying three RHAPs in arthroscopic surgery, particularly with a standard knot pusher and arthroscopic cannulas. The findings of this study indicated the importance of three RHAPs in performing arthroscopic knot tying and provided evidence regarding discrepancies of maximum clinical failure loads observed between orthopaedic surgeons, thereby leading to better surgical outcomes in the future.

Bone Health Improvement Protocol.

INTRODUCTION: Metabolic bone disease is a malady that causes significant morbidity and mortality to a patient who has sustained a fragility fracture. There is currently no protocol to prevent secondary fragility fracture at our institution. The objective of this study was to create an appropriate protocol for implementing clinical pathways for physicians to diagnose and treat osteoporosis and fragility fractures by educating patients. METHODS: A multidisciplinary team created an appropriate protocol that could be implemented in an inpatient setting. A thorough literature review was conducted to evaluate potential barriers and efficacious methods of protocol design. RESULTS: A bone health improvement protocol was developed. Any patient over the age of 50 who sustains a fracture from low energy trauma, such as a fall from standing or less, should be considered to place into this protocol. These patients received education on metabolic bone disease, a prescription for high dose vitamin D therapy, and laboratory testing to determine the etiology of their metabolic bone disease. Continuity of care of these patients with their primary care provider was provided for further management of their metabolic bone disease and evaluation of their disease after discharged from the hospital. DISCUSSION: Comprehensive secondary prevention should consist of osteoporosis assessment and treatment together with a fall risk assessment. With this protocol, secondary fragility fractures potentially could be prevented.