Predicting Leg Forces and Knee Moments Using Inertial Measurement Units: An In Vitro Study.

We compared the ability of seven machine learning algorithms to use wearable inertial measurement unit (IMU) data to identify the severe knee loading cycles known to induce microdamage associated with anterior cruciate ligament rupture. Sixteen cadaveric knee specimens, dissected free of skin and muscle, were mounted in a rig simulating standardized jump landings. One IMU was located above and the other below the knee, the applied three-dimensional action and reaction loads were measured via six-axis load cells, and the three-dimensional knee kinematics were also recorded by a laboratory motion capture system.

Anatomic Acromioclavicular Joint Reconstruction with and without Acromioclavicular Ligament Reconstruction: A Comparative Biomechanical Study.

Background: The purpose of this study was to determine if adding a reconstructed superior acromioclavicular (AC) joint ligament adds significant biomechanical stability to the AC joint over anatomic coracoclavicular (CC) ligament reconstruction alone.

Methods: Fourteen cadaver shoulders were used for the comparison of biomechanical stability among the anatomic CC ligament reconstruction alone, CC and AC ligament reconstruction, and the intact groups by measuring the displacement under cyclic loads. A load to failure test was then performed in the vertical direction at a loading rate of 2 mm /sec to determine surgical-repair joints' tolerance to the maximum failure load.

A Comparison of Inertial Measurement Unit and Motion Capture Measurements of Tibiofemoral Kinematics during Simulated Pivot Landings.

Injuries are often associated with rapid body segment movements. We compared Certus motion capture and APDM inertial measurement unit (IMU) measurements of tibiofemoral angle and angular velocity changes during simulated pivot landings (i.e.

Testing a Quaternion Conversion Method to Determine Human Three-Dimensional Tibiofemoral Angles During an In Vitro Simulated Jump Landing.

Lower limb joint kinematics have been measured in laboratory settings using fixed camera-based motion capture systems; however, recently inertial measurement units (IMUs) have been developed as an alternative. The purpose of this study was to test a quaternion conversion (QC) method for calculating the three orthogonal knee angles during the high velocities associated with a jump landing using commercially available IMUs. Nine cadaveric knee specimens were instrumented with APDM Opal IMUs to measure knee kinematics in one-legged 3-4× bodyweight simulated jump landings, four of which were used in establishing the parameters (training) for the new method and five for validation (testing).

Laboratory Validation of a Wearable Sensor for the Measurement of Head Acceleration in Men's and Women's Lacrosse.

Mild traumatic brain injuries, or concussions, can result from head acceleration during sports. Wearable sensors like the GForceTrackerTM (GFT) can monitor an athlete's head acceleration during play. The purpose of this study was to evaluate the accuracy of the GFT for use in boys' and girls' lacrosse.

A comparison of head injuries in male and female lacrosse participants seen in US emergency departments from 2005 to 2016.

Introduction: In the United States there has been a large increase in participation in lacrosse for both males and females. The purpose of this study was to analyze the number of head injuries, injury rates (calculated using the reported number of participants) and types of head injuries that are seen in emergency departments in the United States.

Methods: We compared injuries between male and female lacrosse participants.

The Interaction of Intramuscular Ketorolac (Toradol) and Concussion in a Rat Model.

The purpose of this study was to examine the interaction of a single dose of Toradol and head impact in an in vivo rat model for sport-related concussion using a validated rat concussion model. Thirty-five Sprague-Dawley rats were placed into one of four groups: (1) Control, (2) Impact Only, (3) Toradol Only, (4) Impact and Toradol. Animals in the impact groups were subjected to a single head impact.

Comparison of ACL Strain in the MCL-Deficient and MCL-Reconstructed Knee During Simulated Landing in a Cadaveric Model.

Background: Noncontact anterior cruciate ligament (ACL) injury after valgus landing has been reported and studied biomechanically. However, the role of the medial collateral ligament (MCL) in dissipating these forces has not been fully elucidated. Purpose/Hypothesis: The purpose of this study was to investigate the role that the MCL plays in ACL strain during simulated landing.

Load to Failure and Stiffness: Anchor Placement and Suture Pattern Effects on Load to Failure in Rotator Cuff Repairs.

Background: Rotator cuff tendinopathy is a frequent cause of shoulder pain that can lead to decreased strength and range of motion. Failures after using the single-row technique of rotator cuff repair have led to the development of the double-row technique, which is said to allow for more anatomical restoration of the footprint.

Purpose: To compare 5 different types of suture patterns while maintaining equality in number of anchors.

A Biomechanical Comparison of Isometric and Anatomic Medial Patellofemoral Ligament Reconstruction.

The purpose of this study was to compare two different methods of medial patellar femoral ligament (MPFL) reconstructions: isometric and anatomic. These were then compared with the native MPFL. Fourteen fresh frozen cadaveric knees were carefully dissected to expose the MPFL.

Temperature Change When Drilling Near the Distal Femoral Physis in a Skeletally Immature Ovine Model.

Background: The possibility of physeal injury during anterior cruciate ligament reconstruction in the pediatric population is a concern. The purpose of this study was to determine whether drilling at or near the physis could cause a temperature increase that could trigger chondrolysis.

Methods: Skeletally immature cadaveric lamb distal femurs were used for this study and randomly placed in 1 of 6 groups (n=10 in each group).

Soccer-Related Injuries in Children and Adults Aged 5 to 49 Years in US Emergency Departments From 2000 to 2012.

Background: An increase in soccer-related injuries occurred in the United States between 2000 and 2012; however, most studies of soccer-related injuries have only examined the pediatric population and not adults.

Hypothesis: The number of soccer injuries is increasing in both the pediatric and adult populations. There are differences in injury types and counts when comparing male and female players within various age groups.

Biomechanical properties of labral repair: simple versus vertical suture pattern.

The goal of this study was to evaluate contact area and surface pressure as a result of different suture patterns in the treatment of anterior shoulder instability caused by a Bankart lesion. Loads were applied through the humeral head to the glenoid surface in the intact shoulder and after simple suture labral repair (n=10) and vertical mattress labral repair (n=9). Peak contact pressure, mean contact pressure, and contact area were recorded for 0°, 45°, and 90° shoulder abduction, and then the repair was loaded to failure.

Immunological response to bolus versus multiple injections of hylan G-F 20 (Synvisc) in a murine biocompatibility model.

Local tissue reactivity to intra-articular injections of hyaluronic acid hylan G-F 20 (Synvisc) has been described. We used a murine biocompatibility model to study the inflammatory response to Synvisc after a single bolus injection versus the traditional three shot series of injections. Air pouches were established subcutaneously in BALB/c mice, which were injected with phosphate-buffered saline (PBS), 5 mg ultra-high molecular weight polyethylene particles (to simulate synthetic joint wear debris, positive control), 0.

Effect of erythromycin-doped calcium polyphosphate scaffold composite in a mouse pouch infection model.

We previously showed that strontium-doped calcium polyphosphate (SCPP) scaffold with poly(vinyl alcohol) (PVA) coating extended the impregnated erythromycin (EM) release. In this study, we examined the bactericidal effect of EM-doped SCPP (SCPP(EM) ) scaffolds with PVA coating in a Staphylococcus aureus (S. aureus) infected mouse pouch.

Anterior horn lateral meniscus tear, repair, and meniscectomy.

The purpose of this study was to describe the effect of anterior horn of the lateral meniscus (AHLM) tears on tibiofemoral contact pressures and the ability to restore normal parameters with repair. Eight fresh-frozen cadaveric knees were used. The specimens were subjected to a load of 1,000 N at 0 and 30 degrees of flexion and peak pressure, force and contact area were recorded.

Biomechanical evaluation of anatomical double-bundle coracoclavicular ligament reconstruction secured with knot fixation versus screw fixation.

Methods to reconstruct the coracoclavicular ligaments anatomically have been described. No clear advantage of 1 technique has been elucidated. The authors' hypothesis was that the biomechanical properties of a modified knot fixation technique would be similar to the anatomical double-bundle technique.

Shear force at failure and stiffness of all-inside meniscal repair devices.

The purpose of this study was to determine the failure load and stiffness of various meniscal repair devices. A total of 61 fresh-frozen porcine menisci (medial and lateral) were used for the study. A 30-mm vertical, full-thickness tear was created and repaired using one of three all-inside fixation devices and one inside-out repair in the vertical mattress pattern.

Anterior internal fixator versus a femoral distractor and external fixation for sacroiliac joint compression and single stance gait testing: a mechanical study in synthetic bone.

Purpose: The purpose of this study was to evaluate the biomechanical stability and compressive forces across the sacroiliac (SI) joint of an anterior internal fixator compared to the femoral distractor and external fixator for vertically unstable pelvic fractures.

Methods: Five composite pelvises with a simulated APC type III injury fixed with a femoral distractor, external fixator, or anterior internal fixator were tested. A pressure-sensitive film (Tekscan) was placed in the disrupted SI joint recording the magnitude of force.

The biomechanical stability of distal clavicle excision versus symmetric acromioclavicular joint resection.

Background: Treatment for acromioclavicular (AC) joint pain may include distal clavicle excision (DCE). It is possible that DCE can disrupt the surrounding ligaments, leading to increased AC joint laxity.

Purpose: To determine the load to failure and stiffness of the AC joint after DCE and symmetric acromioclavicular joint resection (ACJR).

Biomechanical stability of a supra-acetabular pedicle screw internal fixation device (INFIX) vs external fixation and plates for vertically unstable pelvic fractures.

Background: We have recently developed a subcutaneous anterior pelvic fixation technique (INFIX). This internal fixator permits patients to sit, roll over in bed and lie on their sides without the cumbersome external appliances or their complications. The purpose of this study was to evaluate the biomechanical stability of this novel supraacetabular pedicle screw internal fixation construct (INFIX) and compare it to standard internal fixation and external fixation techniques in a single stance pelvic fracture model.

A novel strontium-doped calcium polyphosphate/erythromycin/poly(vinyl alcohol) composite for bone tissue engineering.

It is our goal to develop bactericidal bone scaffolds with osteointegration potential. In this study, poly(vinyl alcohol) (PVA) coating (7%) was applied to an erythromycin (EM)-impregnated strontium-doped calcium polyphosphate (SCPP) scaffold using a simple slurry dipping method. MicroCT analysis showed that PVA coating reduced the average pore size and the percentage of pore interconnectivity to some extent.

Novel angle measurements for assessment of shoulder location using the scapular y radiograph.

Shoulder dislocation is an injury with potential long-term consequences that requires prompt diagnosis and treatment. Patient positioning and imperfect radiographic views may result in discomfort, added examination time, and problematic diagnosis. The scapular Y radiograph has been shown to be useful in diagnosing shoulder dislocation but is not considered sufficient in isolation.