INTRODUCTION: The advent of pedicle screws which provide distraction and derotation has led to higher correction of major curves. Newer methods have been devised to evaluate preoperative coronal flexibility, including lateral-bending (LB), push-prone (PP) and fulcrum-bending (FB) radiographs. Documentation of a consistent radiographic method predictive of correction rate has not been established.

OBJECTIVE: To determine the most predictive radiographic method for evaluating spine flexibility and correction by comparing the correction rate (CR), flexibility rate (FR) and correction index (CI) of the Cobb's angle using the different radiographic methods.

METHODS: Preoperative radiographs of 20 patients who underwent spinal fusion for adolescent scoliosis were obtained using the LB, PP and FB method and compared with postoperative radiographs.

RESULTS: Comparing the mean Cobb angles using the different methods to that of postoperative standing showed that only the FB method is not significantly different from the latter (p=0.669). There was a significant difference between the Cobb's angle measured on the LB and PP and that measured on postoperative standing (p=0.043, p=0.008). Comparing the mean flexibility of the different methods with the mean CR also showed that the mean FR of LB (p=0.007) and PP (p=0.00013) were significantly different from the CR while that of FB is not significantly different from the CR (p=0.687).

CONCLUSION: The FB radiograph demonstrated no statistical difference compared to postoperative radiograph, FR, and CI.

Human ; Male ; Female ; Young Adult ; Adolescent ; Scoliosis ; Pedicle Screws ; Spinal Fusion ; Spine ; Radiography ; Posture ; Documentation

OBJECTIVES: To develop three dimensional computer models of the anterior thoracolumbar spine implants or constructs (the novel single rod-screw implant and the standard implants) and to evaluate its biomechanical properties through a graphically reconstructed testing standard.

METHODS: We developed a finite element modeling technique based on actual geometry of the implant constructs and mechanical property data from standard biomechanical studies on anterior thoracolumbar spinal instrumentation systems. Seven constructs were mounted on simulated vertebral bodies. Axial load sharing was measured through a range of applied axial loads from 100 N to 1600 N. The static destructive tests were conducted. The bending strength of each construct was calculated with a full length corpectomy graft in place, simulating reconstruction of the anterior column, and with no graft in place, simulating catastrophic graft failure.

RESULTS: Static testing parameter demonstrated highly significant differences between devices. The plate construct formed the highest subset in bending strength of 1000-1100 N, whereas the single rod showed the lowest value of 300-400N. However, the bending strengths of single rod and dual rod both without bone grafts were not significantly different. With the graft in place, bending strength of the constructs significantly increased beyond the maximum set of load of 1600N, underlying the importance of the graft in overall construct strength.

CONCLUSION: The 3-D finite element models for anterior thoracolumbar instrumentation system were designed with mechanical properties comparable to the actual biomechanical testing results. Although single rod construct has the lowest value, its bending strength is comparable to the standard dual rod system under static axial loading. Bone graft contributed to overall construct stiffness.

Bone Screws ; Finite Element Analysis ; Weight-bearing ; Bone Plates ; Lumbar Vertebrae ; Bone Transplantation

BACKGROUND: Studies comparing the relative strength of polymethylmethacrylate (PMMA) augmented fixation, standard plating and locked compression plate (LCP) system are few. The use of either the bone cement-augmented dynamic compression plate or the Hybrid LCP constructs may provide an additional tool for the treatment of fractures in patients with osteoporosis.

METHODS: Eighteen (18) osteoporotic cadaveric humeral bones were assigned randomly to each of three groups (Dynamic Compression Plate [DCP], DCP augmented with bone cement, and the Hybrid LCP system) and tested in anterior-posterior bending and torsion/external rotation. The load to failure values were obtained and the results for each specimen compared.

RESULTS: Significant differences were observed between the standard DCP and Hybrid LCP group (p-value=0.012), and in the cement-augmented and Hybrid LCP group (p-value=0.099) in torsion/external rotation loading. No significant difference was observed between the standard DCP and bone-cement augmented group (p-value=0.248). No significant difference was observed among the three groups in terms of stiffness (p-value=0.3868) in the four-point anterior-posterior bending modality. Screw pull-out of the implant was observed only in the regular DCP group in torsion/external rotation loading stress.

CONCLUSION: Significant differences were seen between the three constructs in torsion/external rotation but not in anterior-posterior four-point bending. Bone failure, but not screw pull-out, was seen in the Hybrid LCP and bone cement-augmented DCP groups in torsion. This study showed that the LCP system and the bone cement-augmented constructs may provide greater screw purchase to the osteoporotic humerus.

Human ; Humans ; Bone Cements ; Bone Screws ; Polymethyl Methacrylate ; Rotation ; Bone Plates ; Fracture Fixation, Internal ; Fractures, Bone ; Osteoporosis ; Humerus

Background: Minimally invasive spine surgical techniques (MISST) are associated with less intraoperative blood loss, shorter duration of surgery, and less post-operative pain. In the last two decades, MISST have been performed on an outpatient basis in developed countries but it is still performed primarily on an inpatient basis in the Philippines. This study aims to determine the safety and effectiveness of performing MISST in an ambulatory surgical center in the Philippines.

Methods: A retrospective chart review of patients who underwent MISST in an ambulatory surgical center (ASC) in Manila, Philippines, from January 2014 to December 2018 was done. The different types of MISST were identified and analyzed as to patient demographic characteristics, anesthetic perioperative management, outcomes and complications.

Results: Out of 337 patients included in the review, 8 types of MISST were identified. The average patient age was 55.61 years. Majority (98.2%) of the patients were classified as American Society of Anesthesiologists (ASA) physical status I or II. All patients had a statistically significant (p < 0.05) reduction in pain scores. ASC length of stay varied based on the complexity of the procedure ranging from 2.1 to 12.9 hours. There was a 0.89% incidence of surgery-related complications. Majority (94.4%) of the patients were discharged to home. There was no mortality.

Conclusion: Even in a developing country, transitioning MISST from inpatient to the ambulatory setting can be performed with minimal complications and unplanned hospital admissions while still achieving significant pain reduction. The key elements include careful patient selection, close coordination between the anesthesia and spine surgical teams, and provision of multimodal analgesia.

Ambulatory Surgical Procedures

The history of the Department of Anatomy of the College of Medicine of the University of the Philippines can be chronicled from its humble beginnings in 1907 to its continued existence through the COVID-19 pandemic. This article briefly describes its historical development, current undertakings, and future directions in relation to its mission and vision.
COVID-19 ; Medicine ; Universities

Background: The use of 3D printing in medical education, prosthetics, and preoperative planning requires dimensional accuracy of the models compared to the replicated tissues or organs. Objective. To determine the dimensional accuracy of 3D-printed models replicated from metacarpal bones from cadavers. Methods: Fifty-two models were 3D-printed using fused deposition modeling (FDM), stereolithography (SLA), digital light processing (DLP), and binder jetting method from 13 right first metacarpal bones of cadavers from the College of Medicine, University of the Philippines Manila. Six dimensional parameters of the 3D-printed models and their control bones were measured using 0.01 mm calipers — length, midshaft diameter, base width, base height, head width, and head height. Mean measurements were compared using non-inferiority testing and multidimensional scaling. Results: Mean measurements of the 3D-printed models were slightly larger than their control bones (standard deviation range: 1.219-4.264; standard error range, 0.338-1.183). All models were found to be at least 90% accurate and statistically non-inferior compared to control bones. DLP-printed models were the most accurate (base width, 99.62 %) and most similar to their control bone (–0.05, 90% CI –0.34, 0.24). Through multidimensional scaling, DLP-printed models (coordinate = 0.437) were the most similar to the control bone (coordinate = 0.899). Conclusion The 3D-printed models are dimensionally accurate when compared to bones.
Stereolithography ; Dimensional Measurement Accuracy ; Printing, Three-Dimensional

Objective: This study aimed to determine the perceptions of rehabilitation medicine resident trainees on using modified Thiel soft-embalmed cadavers as a learning tool in acquiring knowledge on musculoskeletal ultrasound (MSK-UTZ) and anatomy. Methods: This descriptive cross-sectional study used total enumeration to recruit residents in training under the rehabilitation medicine department of a tertiary referral hospital. An online survey tool was self-administered to determine their perceptions on the use of MSK-UTZ on Thiel-embalmed cadavers. Pre- and post-test scores were compared to determine if their knowledge has improved. Results: Fifteen participants were recruited, who answered the pre- and post-test, and the online survey. The mean pre-test score of participants was 5.87 (±1.68), and the mean post-test score was 6.87 (±2.00). There was no statistically significant difference (P = 0.20) using a paired t-test. At an arbitrary passing rate of 70%, only 5/15 participants passed the pre-test while 10/15 passed the post-test. A chi-square test of independence showed that there was no significant association between the number of participants who passed or failed on the pre- and posttest, X2 (1, N = 15) = 3.3, p = .0.068. Most of the perceptions of the participants were positive in terms of the use of modified Thiel soft-embalmed cadavers as a learning tool, its relevance in the training of a rehabilitation medicine resident, and the overall experience on its use. Conclusion Thiel-embalmed cadavers as a learning tool was well-accepted, having generally positive perceptions from the participants mainly in terms of perceived enhancement of the understanding of the anatomical basis of musculoskeletal ultrasound, perceived improvement in skills in performing musculoskeletal ultrasound, and most even recommended that it be part of their training as rehabilitation medicine residents. In terms of acquiring knowledge on musculoskeletal ultrasound (MSK-UTZ) and anatomy, no significant improvement in knowledge was noted. Further studies with larger sample sizes are recommended to yield more statistically significant improvement in knowledge and to observe trends in the perceptions of participants.
Education, Medical ; Anatomy

Abstract
Education, Medical ; Anatomy

BACKGROUND: Instrumented posterior cervical spine surgery (IPCSS) can be conducted using screws inserted through the pedicles of the vertebra. A safe IPCSS method uses 3D-printing to produce templates that will serve as drill guides for screw placement. OBJECTIVES: This study describes the generation of 3D-printed drill guides using low-cost general purpose 3D modeling software and the comparison of screw insertion accuracy scores against the traditional landmark method and guides created using commercial grade software. METHODS: Twenty-five (25) subaxial pedicles of five cadaveric spines were selected and scanned using computed tomography (CT). A digital reconstruction of the five cadaveric spines were created based on the CT DICOM data. A low-cost 3D modeling software, Rhinoceros 3D, was utilized for trajectory planning and generation of a patientspecific drill template using the digital reconstruction. The templates were then fabricated in ABS plastic using a fused deposition modeling (FDM) 3D printer. Insertion of cervical pedicle screws on the cadaveric spines was done by an orthopedic resident using the 3D printed guides. Postoperative CT scans were obtained, and placement accuracy of the screws were scored by two assessors utilizing a four-point rating system. Screws in correct placement were scored Grade 0 while misplaced screws with neurovascular damage were given a score of Grade 3. RESULTS: Accuracy scores for the 3D-printed drill guides were 52% for assessor 1 and 44% for assessor 2. For assessor 1, screw placement in C3, C6, and C7 received the highest scores. For assessor 2, the highest scores were achieved in C3 and C7. The hybrid method of Bundoc et al. achieved scores of 94% while 3D printed guides utilizing commercial software like Materialise Mimics, Geomagic Freeform, or UG Imageware achieved scores of 80-100%. The traditional landmark method had scores ranging from 12% to 94% depending on the skill of the surgeon. CONCLUSION Commercial medical 3D image-based engineering software has high acquisition costs that might be beyond the reach of most institutions. A sub-$1000 general purpose 3D modeling software can be used to create drill templates. Several factors were identified in the design and fabrication of the template that can be addressed to increase accuracy. Trajectory planning can also be improved by automating the process. The researchers recommend further studies in these areas specially in the context of developing 3D printing as a support service for surgical operations in the Philippines.