Miguel Pirela-Cruz

Collaborative virtual environments for orthopedic surgery

Virtual reality simulators can be beneficial in increasing the quality of training while decreasing the time needed for training a specific skill. These simulators can provide a risk free environment which has the benefit of repetition and correction of the users error. It has been years since the introduction of these simulators into the medical applications. The application of VR in orthopedic surgery, however, is a relatively new area of interest. In this paper, collaborative virtual reality based environments with the application in orthopedic surgery, with a focus on LISS (Less Invasive Stabilization System) plating, is presented. They can be used for training medical residents in orthopedic surgery.

Dog bites to the upper extremity in children

Dog bites are common injuries in children. A large percentage of these dog bites affect the upper extremity. There is little information describing the results of treatment of upper extremity injuries in children.

An advanced simulator for orthopedic surgical training.

PurposeThe purpose of creating the virtual reality (VR) simulator is to facilitate and supplement the training opportunities provided to orthopedic residents. The use of VR simulators has increased rapidly in the field of medical surgery for training purposes. This paper discusses the creation of the virtual surgical environment (VSE) for training residents in an orthopedic surgical process called less invasive stabilization system (LISS) surgery which is used to address fractures of the femur.MethodThe overall methodology included first obtaining an understanding of the LISS plating process through interactions with expert orthopedic surgeons and developing the information centric models. The information centric models provided a structured basis to design and build the simulator. Subsequently, the haptic-based simulator was built. Finally, the learning assessments were conducted in a medical school.ResultsThe results from the learning assessments confirm the effectiveness of the VSE for teaching medical residents and students. The scope of the assessment was to ensure (1) the correctness and (2) the usefulness of the VSE. Out of 37 residents/students who participated in the test, 32 showed improvements in their understanding of the LISS plating surgical process. A majority of participants were satisfied with the use of teaching Avatars and haptic technology. A paired t test was conducted to test the statistical significance of the assessment data which showed that the data were statistically significant.ConclusionThis paper demonstrates the usefulness of adopting information centric modeling approach in the design and development of the simulator. The assessment results underscore the potential of using VR-based simulators in medical education especially in orthopedic surgery.

A technical note on percutaneous scaphoid fixation using a hybrid technique.

This article describes a percutaneous fixation technique for a midwaist scaphoid fracture using an antegrade (dorsal) guidewire and a retrograde (volar) cannulated screw placement. This simplified hybrid technique allows for accurate dorsal central wire placement and stable internal fixation with minimal violation of the articular cartilage of the proximal pole of the scaphoid.

Humeral Rotational Osteotomy for Shoulder Deformity in Obstetric Brachial Plexus Palsy: Which Direction Should I Rotate?

Shoulder internal rotation contracture is the most common deformity affecting the shoulder in patients with Obstetric Brachial Plexus Palsy. With progression of the deformity, the glenohumeral joint starts to subluxate and then dislocates. This is accompanied with bony changes of both the humerus and the glenoid. Two opposite direction humeral osteotomies have been proposed for this condition (internal rotation osteotomy (IRO) and external rotation osteotomy (ERO)). This fact of different direction osteotomies has not adequately been explained in the literature. Most orthopedic surgeons may not be able to fully differentiate between these two osteotomies regarding the indications, outcomes and effects on the joint. This review explains these differences in details.

An Information Model for Designing Virtual Environments for Orthopedic Surgery

In this paper, the role of an information model in the design of virtual environments for orthopedic surgery is discussed. The engineering Enterprise Modeling Language (eEML) is used to model the relationships and precedence constraints in a specific set of orthopedic surgery activities. Our model focuses on a process referred to as LISS plating surgery (LISS- Less Invasive Stabilization System). This information model serves as a basis to develop two orthopedic surgical environments: a non-immersive virtual reality based environment and a haptic interface equipped virtual environment. These virtual environments can be used for training medical residents in specific orthopedic surgical processes.

Assessment of four midcarpal radiologic determinations

Several radiologic measurement methods have been described for determining static carpal alignment of the wrist. These include the scapholunate, radiolunate, and capitolunate angles. The triangulation method is an alternative radiologic measurement which we believe is easier to use and more reproducible and reliable than the above mentioned methods. The purpose of this study is to assess the intraobserver reproducibility and interobserver reliability of the triangulation method, scapholunate, radiolunate, and capitolunate angles. Twenty orthopaedic residents and staff at varying levels of training made four radiologic measurements including the scapholunate, radiolunate and capitolunate angles as well as the triangulation method on five different lateral, digitized radiographs of the wrist and forearm in neutral radioulnar deviation. Thirty days after the initial measurements, the participants repeated the four radiologic measurements using the same radiographs. The triangulation method had the best intra-and-interobserver agreement of the four methods tested. This agreement was significantly better than the capitolunate and radiolunate angles. The scapholunate angle had the next best intraobserver reproducibility and interobserver reliability. The triangulation method has the best overall observer agreement when compared to the scapholunate, radiolunate, and capitolunate angles in determining static midcarpal alignment. No comment can be made on the validity of the measurements since there is no radiographic gold standard in determining static carpal alignment.

Correction of extra-articular distal radius malunions using an anatomic radial plate.

Malunion is a debilitating complication of a distal radius fracture. The malunion often requires a corrective osteotomy to restore the stability and joint congruity about the distal radius, a procedure which offers tremendous benefits in terms of pain, strength, and functionality. Here we describe a unique technique to address the malunion of an extra-articular distal radius fracture using a radial anatomic plate. This is a simple and reproducible method of fixation involving straightforward anatomy, which does not require excessive radiography, and which represents an excellent choice of fixation in the distal radius malunion.

The Scaphoid Staple A Systematic Review

Background: The purpose of this systematic review is to analyze the indications, outcomes, and complications of scaphoid fixation with a staple. Methods: The literature was reviewed for all cases of the scaphoid staple. Five articles including 188 patients, of 77 primary scaphoid fractures and 111 other indications that included delayed union, nonunion, and avascular necrosis, were reviewed. Demographic data, outcomes, and complications were recorded. Results: The union rate of the scaphoid staple is 94.7%, and 95.7% of patients return to work after an average of 9.8 weeks after a 4.7-week period of immobilization. The complication rate was 9.0%, and 7.5% required hardware removal. Clinical and radiographic healing was higher in primary fractures as compared with other indications. Other indications, as compared with primary fracture, had a higher rate of hardware removal. Conclusions: For all indications, the scaphoid staple has a high union rate and a low complication rate. In the authors’ experience, the procedure is fast, not technically challenging, and may be considered for primary fracture, delayed union, nonunion, and avascular necrosis of the scaphoid.

Outcomes Following Isolated Posterior Interosseous Nerve Neurectomy: A Systematic Review:

Background: Posterior interosseous nerve neurectomies (PINN) are an option in the treatment of chronic dorsal wrist pain. However, the literature describing PINN consists primarily of small case series, and the procedure is typically done as an adjunct treatment; therefore, the outcomes of the PINN itself are not well known. We performed a systematic review of the literature to provide characteristics of patients following a PINN. Methods: A systematic review of the literature was performed. Papers published in the PubMed database in English on isolated PINN were included. Articles in which a PINN was performed as an adjunct were excluded. Primary outcomes were return to work, patient satisfaction, pain/function scores, wrist range of motion, complications, and pain recurrence. Weighted averages were used to calculate continuous data, whereas categorical data were noted in percentages. Results: The search yielded 427 articles including 6 studies and 135 patients (136 cases). The average age was 43.6 years (range, 17-75), and most patients were female (54.1%). At an average final follow-up of 51 months, 88.9% of patients were able to return to work. After initial improvement, a recurrence of pain occurred in 25.5% of patients at an average of 12.3 months. Excluding recurrence of pain, the complication rate was 0.9%, including 1 reflex sympathetic dystrophy. Overall, 88.4% of patients experienced a subjective improvement and were satisfied with the procedure. Conclusions: Isolated PINN have shown excellent clinical outcomes, with few patients experiencing recurrent pain at long-term follow-up. PINN can provide relief in patient’s chronic wrist pain.