Practice Patterns Vary Widely in the Care of Pediatric and Adolescent Pelvic and Acetabular Fractures: A CORTICES Survey.

Introduction: Pediatric pelvic and acetabular fractures are rare but potentially devastating injuries and significant management variation exists across the United States. This study sought to elucidate treatment decision-making trends, involvement of adult trauma fellowship-trained surgeons in pediatric care, and pre- and postoperative transfer patterns.

Methods: Pediatric orthopaedic surgeons who serve as trauma liaisons at 20 PTCs were surveyed regarding training, practice volume, and factors contributing to institutional management of pelvic and acetabular injuries.

Hip Instability in Children With Spinal Muscular Atrophy: A Retrospective Study.

Purpose: Hip subluxation and dislocation are known problems for children with spinal muscular atrophy (SMA). Medical complexity of these children typically results in absence of monitoring and intervention for pathologic hips. Patterns of hip migration and acetabular morphology in SMA have not been described.

Retrograde Insertion Approach for Anterior Distal Femoral Hemiepiphysiodesis Procedure: A Case Report.

Case: A 13-year-old adolescent boy with spastic diplegic cerebral palsy (CP) presented with crouch gait and bilateral knee flexion contractures (KFCs). After failure of conservative treatments, the patient was referred to orthopaedics for surgical intervention. Anterior distal femoral hemiepiphysiodesis (ADFH), using a retrograde approach, and Strayer gastrocnemius recession were performed bilaterally.

Two aspects of feed-forward control of action stability: effects of action speed and unexpected events.

We explored two types of anticipatory synergy adjustments (ASA) during accurate four-finger total force production task. The first type is a change in the index of force-stabilizing synergy during a steady state when a person is expecting a signal to produce a quick force change, which is seen even when the signal does not come (steady-state ASA). The other type is the drop in in the synergy index prior to a planned force change starting at a known time (transient ASA).

Three Levels of Neural Control Contributing to Performance-stabilizing Synergies in Multi-finger Tasks.

We tested a hypothesis on force-stabilizing synergies during four-finger accurate force production at three levels: (1) The level of the reciprocal and coactivation commands, estimated as the referent coordinate and apparent stiffness of all four fingers combined; (2) The level of individual finger forces; and (3) The level of firing of individual motor units (MU). Young, healthy participants performed accurate four-finger force production at a comfortable, non-fatiguing level under visual feedback on the total force magnitude. Mechanical reflections of the reciprocal and coactivation commands were estimated using small, smooth finger perturbations applied by the "inverse piano" device.

Force matching: motor effects that are not reported by the actor.

We explored unintentional drifts of finger forces during force production and matching task. Based on earlier studies, we predicted that force matching with the other hand would reduce or stop the force drift in instructed fingers while uninstructed (enslaved) fingers remain unaffected. Twelve young, healthy, right-handed participants performed two types of tasks with both hands (task hand and match hand).

Effect of split posterior tibialis tendon transfer on foot progression angle in children with cerebral palsy.

Objectives: A common orthopedic issue for patients with spastic cerebral palsy (CP) is hindfoot varus deformity. One method of treatment is the split posterior tibialis tendon transfer (SPOTT). There is limited literature on the effect of SPOTT on foot progression angle (FPA) in children with CP who have equinovarus deformities.

Two classes of action-stabilizing synergies reflecting spinal and supraspinal circuitry.

We explored force-stabilizing synergies during accurate four-finger constant force production tasks in spaces of finger modes (commands to fingers computed to account for the finger interdependence) and of motor unit (MU) firing frequencies. The main specific hypothesis was that the multifinger synergies would disappear during unintentional force drifts without visual feedback on the force magnitude, whereas MU-based synergies would be robust to such drifts. Healthy participants performed four-finger accurate cyclical force production trials followed by trials of constant force production.

Effects of fatigue on intramuscle force-stabilizing synergies.

We applied the recently introduced concept of intramuscle synergies in spaces of motor units (MUs) to quantify indexes of such synergies in the tibialis anterior during ankle dorsiflexion force production tasks and their changes with fatigue. We hypothesized that MUs would be organized into robust groups (MU modes), which would covary across trials to stabilize force magnitude, and the indexes of such synergies would drop under fatigue. Healthy, young subjects ( = 15; 8 females) produced cyclical, isometric dorsiflexion forces while surface electromyography was used to identify action potentials of individual MUs.

Motor unit-based synergies in a non-compartmentalized muscle.

The concept of synergies has been used to address the grouping of motor elements contributing to a task with the covariation of these elements reflecting task stability. This concept has recently been extended to groups of motor units with parallel scaling of the firing frequencies with possible contributions of intermittent recruitment (MU-modes) in compartmentalized flexor and extensor muscles of the forearm stabilizing force magnitude in finger pressing tasks. Here, we directly test for the presence and behavior of MU-modes in the tibialis anterior, a non-compartmentalized muscle.

Rectus femoris transfers with and without a hamstring lengthening will not change hip kinematics in children with cerebral palsy.

Background: A rectus femoris transfer (RFT) surgery with and without a hamstring lengthening (HSL) is used to treat stiff-knee gait in children with cerebral palsy (CP). While current literature has reported that a RFT surgery improves the kinematics at the knee, little is known about the kinematic changes at the hip.

Research Question: Does a RFT surgery change hip joint kinematics in children with CP?

Methods: This retrospective study included children (<18 years old) diagnosed with CP, who underwent a RFT procedure, and who were seen at our institution's accredited clinical motion laboratory.

Delayed Radial Nerve Palsy after Closed Reduction of a Pediatric Humeral Shaft Fracture.

Humeral shaft fractures are common in the United States and may be associated with radial nerve injuries due to their close anatomic relationship in the spiral groove. Most radial nerve palsies are found at presentation due to the initial trauma; however, they can present secondary to orthopaedic intervention following reduction. In this case report, we present a case of delayed radial nerve palsy in a pediatric patient that was identified four days after closed reduction and splinting which required open reduction, nerve exploration, and internal fixation.

Posterolaterally displaced and flexion-type supracondylar fractures are associated with a higher risk of open reduction.

To identify factors predictive of the risk of conversion from closed to open reduction. International Classification of Disease-9 codes were used to identify completely displaced pediatric supracondylar humerus fractures that were subjected to planned closed reduction and percutaneous pinning. Clinical and radiographic variables were retrospectively collected.

Fracture of the cuboid.

Cuboid fracture accounts for a minority of all foot fractures in adults and often is indicative of a multiply injured foot. Understanding the normal anatomy and function of the cuboid and its relation to foot biomechanics is necessary for appropriate management. Clinical evaluation includes history, physical examination, and thorough assessment of the skin and soft tissues.