Adherence Monitor for Measurement of Removable Cast Walker Wear-Time: Multiple Sensors and Predictive Analytics Improve Accuracy.

Background: Treatment of diabetes and its complications is a primary health care expense. Up to 25% of people with diabetes will develop diabetic foot ulcers (DFUs). Removable cast walker (RCW) boots commonly prescribed for DFU treatment, promote healing, and provide offloading and wound protection.

Prosthesis design and likelihood of achieving physiological range of motion after cervical disc arthroplasty: analysis of range of motion data from 1,173 patients from 7 IDE clinical trials.

Background Context: The functional goals of cervical disc arthroplasty (CDA) are to restore enough range of motion (ROM) to reduce the risk of accelerated adjacent segment degeneration but limit excessive motion to maintain a biomechanically stable index segment. This motion-range is termed the "Physiological mobility range." Clinical studies report postoperative ROM averaged over all study subjects but they do not report what proportion of reconstructed segments yield ROM in the Physiological mobility range following CDA surgery.

Coupled rotation patterns in cervical spine axial rotation can change when the head is kept level.

The biomechanical literature describes axial rotation occurring coupled with lateral bending and flexion in the cervical spine. Since the head is kept level during some activities of daily living, we set out to investigate the changes in total and segmental motion that occur when a level gaze constraint is applied to cadaveric cervical spine specimens during axial rotation. 1.

Republication of "A Biomechanical Comparison of Limited Open Versus Krackow Repair for Achilles Tendon Rupture".

Background: Soft tissue complications after Achilles tendon repair has led to increased interest in less invasive techniques. Various limited open techniques have gained popularity as an alternative to open operative repair. The purpose of this study was to biomechanically compare an open Krackow and limited open repair for Achilles tendon rupture.

Simulated Weightbearing and Articular Injury From Transarticular Screws in a Ligamentous Lisfranc Injury Model.

Background: Transarticular screw fixation is a common surgical treatment for tarsometatarsal ligamentous (Lisfranc) injuries. Iatrogenic damage to articular cartilage from screw placement, however, has been thought to potentially lead to increased risk of tarsometatarsal (TMT) joint arthritis after initial injury. To date, no study has evaluated the effect of weightbearing on articular cartilage after screw fixation.

Bone cutting efficiency and heat generation using a traditional fluted Burr and a novel fluteless resurfacing tool.

Background: Powered instrumentation is often used for bone preparation and/or removal in many orthopaedic procedures but does risk thermogenesis. This study compares biomechanical properties of a fluted burr and a novel fluteless resurfacing tool.

Methods: Twenty cadaveric metatarsals were tested with four predetermined cutting forces to evaluate heat generation and cutting rate for the fluted burr and fluteless resurfacing tool over 40 s or until a depth of 4 mm was reached.

Comparison of the biomechanical stability of transverse and oblique screw trajectories in retrograde intramedullary nailing of supracondylar femur fractures.

Background: The goal was to determine the effect of addition of oblique trajectory distal interlock screws to a retrograde intramedullary femoral nail on implant stability (stiffness), cycles to failure and mode of failure. The hypothesis was that addition of oblique screws would increase implant stability and number of loading cycles to failure.

Methods: Eight matched pairs were tested; one femur implanted with a femoral nail with only transverse distal interlock screws and the other with transverse and oblique interlock screws.

Comparison of a Novel Modified All-Suture Construct versus Suspensory Suture-button Fixation in a Syndesmotic Injury Model.

Objectives: To biomechanically investigate a novel modified all-suture construct compared with commercially available suspensory button fixation for stabilization of the syndesmosis.

Methods: Eight matched pairs of cadaver lower limbs were obtained. We used a material testing machine and Optotrak optoelectronic 3D motion measurement system for testing.

Kinematics of a cervical disc prosthesis implanted above or below one- and two-level fusions.

Background: The theoretical advantages of hybrid constructs over multi-level fusion have been illustrated in clinical and biomechanical studies. However, there is no biomechanical data on hybrid constructs using load control analyses. There is also no clear data on whether there is a biomechanical difference if the arthroplasty is below or above a 1- or 2-level fusion.

Biomechanical Role of the Superior Capsule in a Rotator Cuff Sectioned and Repaired State: A Sequential Sectioning Study.

Background: Individual contributions of the rotator cuff (RC) and superior capsule (SC) to prevent superior translation of the humerus are not well understood.

Purpose: To evaluate the relative contributions of the SC and RC to normal and pathologic shoulder biomechanics by determining their independent effects on superior humeral translation.

Study Design: Controlled laboratory study.

Superficial Deltoid Ligament and Deep Deltoid Ligament Play Equally Important Roles in the Stability of Isolated Lateral Malleolus (OTA/AO 44-B1) Fractures: A Biomechanical Study.

Objective: To evaluate the individual contributions to stability of the superficial and deep deltoid ligaments in the setting of SER IV ankle fractures.

Methods: Nineteen total cadaveric specimens were used. SER IV injuries were created with the rupture of either the superficial (SER IV-S) (n = 9) or deep deltoid (SER IV-D) (n = 10).

Effect of K-wire Reuse and Drill Mode on Heat Generation in Bone.

Background: We examined the effect of Kirschner wire (K-wire) reuse and use of oscillating mode on heat generation within cortical bone.

Methods: Two trocar-tipped K-wires were drilled through the diaphysis of each of 30 human metacarpals and phalanges: one K-wire was inserted in rotary mode and another in oscillating mode. Each wire was reused once.

Osteoinductivity and biomechanical assessment of a 3D printed demineralized bone matrix-ceramic composite in a rat spine fusion model.

We recently developed a recombinant growth factor-free bone regenerative scaffold composed of stoichiometric hydroxyapatite (HA) ceramic particles and human demineralized bone matrix (DBM) particles (HA-DBM). Here, we performed the first pre-clinical comparative evaluation of HA-DBM relative to the industry standard and established positive control, recombinant human bone morphogenetic protein-2 (rhBMP-2), using a rat posterolateral spinal fusion model (PLF). Female Sprague-Dawley rats underwent bilateral L4-L5 PLF with implantation of the HA-DBM scaffold or rhBMP-2.

Loading of the lumbar spine during transition from standing to sitting: effect of fusion versus motion preservation at L4-L5 and L5-S1.

Background Context: Transition from standing to sitting significantly decreases lumbar lordosis with the greatest lordosis-loss occurring at L4-S1. Fusing L4-S1 eliminates motion and thus the proximal mobile segments maybe recruited during transition from standing to sitting to compensate for the loss of L4-S1 mobility. This may subject proximal segments to supra-physiologic flexion loading.

Effectiveness of cervical zero profile integrated cage with and without supplemental posterior Interfacet stabilization.

Background: Conditions requiring cervical decompression and stabilization are commonly treated using anterior cervical discectomy and fusion using an anterior cage-plate construct. Anterior zero profile integrated cages are an alternative to a cage-plate construct, but literature suggests they may result in less motion reduction. Interfacet cages may improve integrated cage stability.

Neutral cervical sagittal vertical axis and cervical lordosis vary with T1 tilt.

Objective: The authors conducted a study to determine whether a change in T1 tilt results in a compensatory change in the cervical sagittal vertical axis (SVA) in a cadaveric spine model.

Methods: Six fresh-frozen cadavers (occiput [C0]-T1) were cleaned of soft tissue and mounted on a customized test apparatus. A 5-kg mass was applied to simulate head weight.

Biomechanical Analysis of Stand-alone Lateral Lumbar Interbody Fusion for Lumbar Adjacent Segment Disease.

Study design Biomechanical cadaveric study  Objective To compare biomechanical properties of a single stand-alone interbody fusion and a single-level pedicle screw construct above a previous lumbar pedicle fusion. Summary of background data Adjacent segment disease (ASD) is spondylosis of adjacent vertebral segments after previous spinal fusion. Despite the consensus that ASD is clinically significant, the surgical treatment of ASD is controversial.

Deltoid ligament repair reduces and stabilizes the talus in unstable ankle fractures.

Introduction: Treatment of supination external rotation type IV (SER-IV) ankle injuries has focused on reduction and fixation of the fibula and syndesmosis (ORIF), not repair of the deltoid ligament.

Methods: Twenty-one ankles were analyzed with a motion capture system. Uninjured ankles were stressed and compared to ankles with SER-IV injuries, then with ORIF, and finally ORIF and deltoid repair.

Biomechanical Analysis of Instability in Rotational Distal Fibula Fractures (OTA/AO 44-B1) With an Intact Deltoid Ligament.

Objectives: To biomechanically analyze instability in supination external rotation (SER) II/III patterns.

Methods: Nineteen cadaver legs were tested in a mechanical jig. One, 2, 3, and 4 Nm of external rotation were applied to intact ankles, SER II injuries, and SER III injuries.

Biomechanical Properties of a Novel Mesh Suture in a Cadaveric Flexor Tendon Repair Model.

Purpose: Conventional suture repairs, when stressed, fail by suture rupture, knot slippage, or suture pull-through, when the suture cuts through the intervening tissue. The purpose of this study was to compare the biomechanical properties of flexor tendon repairs using a novel mesh suture with traditional suture repairs.

Methods: Sixty human cadaveric flexor digitorum profundus tendons were harvested and assigned to 1 of 3 suture repair groups: 3-0 and 4-0 braided poly-blend suture or 1-mm diameter mesh suture.

Biomechanics of an Articulated Screw in Acute Scapholunate Ligament Disruption.

 An injury to the scapholunate interosseous ligament (SLIL) leads to instability in the scapholunate joint. Temporary fixation is used to protect the ligament during reconstruction or healing of the repair. Rigid screw fixation-by blocking relative physiological motion between the scaphoid and lunate-can lead to screw loosening, pullout, and fracture.

Single-screw Fixation of Adolescent Salter-II Proximal Humeral Fractures: Biomechanical Analysis of the "One Pass Door Lock" Technique.

Background: Pin fixation of Salter-II proximal humeral fractures in adolescents approaching skeletal maturity has potential complications that can be avoided with single-screw fixation. However, the strength of screw fixation relative to parallel and diverging pin fixation is unknown. To compare the biomechanical fixation strength between these fixation modalities, we used synthetic composite humeri, and then compared these results in composite bone with cadaveric humeri specimens.

A biomechanical comparison study of a modern fibular nail and distal fibular locking plate in AO/OTA 44C2 ankle fractures.

Background: A lateral approach with open reduction and internal fixation with a plate is a very effective technique for the majority of distal fibular fractures. However, this open approach for ankle fixation may be complicated by wound dehiscence and infection, especially in high-risk patients. An alternative to plating is an intramedullary implant, which allows maintenance of length, alignment, and rotation and which allows for decreased soft tissue dissection.