Background:
The treatment of osteochondral defects (OCDs) constitutes a major problem for orthopaedic surgeons. The altered mechanics and the cell types, with associated soluble factors derived from ...the exposed subchondral bone, are likely responsible for the mechanically and structurally inferior articular cartilage subsequently obtained as a repair tissue. There is therefore an unmet clinical need for bioresponsive biomaterials that allow cell delivery, reduce cell infiltration from the bone marrow, and support chondrogenesis in the presence of joint mechanical loading.
Purpose:
To develop a cell-laden injectable biomaterial, with bioadhesive properties, low cell invasion, and good mechanoresilience, in which simulated joint loading could induce tissue maturation through the production and activation of transforming growth factor beta 1 (TGF-β1).
Study Design:
Controlled laboratory study.
Methods:
Human bone marrow–derived mesenchymal stromal/stem cells were encapsulated in tyramine-modified hyaluronic acid (HA-Tyr) hydrogels, with crosslinking initiated by the addition of horseradish peroxidase (HRP) and various concentrations of hydrogen peroxide (H2O2; 0.3-2 mM). Cytocompatibility and biomechanical and adhesive properties were analyzed by live/dead staining, rheology, and push-out test, respectively. For multiaxial loading, cell-laden hydrogels were subjected to 10% compression superimposed onto a 0.5-N preload and shear loading (±25°) at 1 Hz for 1 hour per day and 5 times a week for 4 weeks. TGF-β1 production and activation were measured by enzyme-linked immunosorbent assay (ELISA).
Results:
The viscoelastic properties of the cell-laden HA-Tyr hydrogels, as crosslinked with different ratios of HRP and H2O2, were demonstrated for a range of cell densities and HRP/H2O2 concentrations. In the absence of serum supplementation, cell invasion into HA-Tyr hydrogels was minimal to absent. The bonding strength of HA-Tyr to articular cartilage compared favorably with clinically used fibrin gel.
Conclusion:
HA-Tyr hydrogels can be mechanically conditioned to induce activation of endogenous TGF-b1 produced by the embedded cells. HA-Tyr hydrogels function as cell carriers supporting biomechanically induced production and activation of TGF-β1 and as bioadhesive materials with low cell invasion, suggesting that they hold promise as a novel biomaterial for OCD repair strategies.
Clinical Relevance:
Leveraging physiological joint mechanics to support chondrogenic graft maturation in an optimized mechanosensitive hydrogel in the absence of exogenous growth factors is of highest interest for OCD repair.
Purpose
Growth-friendly spinal implants (GFSI) were established for scoliotic children as an interim solution until definite spinal fusion could be performed during puberty. While deformity control ...was clearly proven, the effects on vertebral shape and morphology are still unclear. Our prospective study assesses the effect of GFSI with continuous distraction on vertebral body shape and volume in SMA children in comparison with previously untreated age-matched SMA patients.
Methods
Cohort I (
n
= 19, age 13.2 years) were SMA patients without prior surgical scoliosis treatment. Cohort II (
n
= 24, age 12.4 years) were children, who had continuous spinal distraction with GFSI for 4.5 years. Radiographic measurements and computed tomography (CT) 3D volume rendering were performed before definite spinal fusion. For cohort II, additional radiographs were analyzed before the first surgical implantation of GFSI, after surgery and every year thereafter.
Results
Our analysis revealed decreased depth and volume in scoliotic patients with prior GFSI compared to scoliotic patients without prior implants. This difference was significant for the lower thoracic and entire lumbar spine. Vertebral body height and pedicle size were unchanged between the two cohorts.
Conclusion
CT data showed volume reduction in the vertebral body in scoliotic children after GFSI treatment. This effect was more severe in the lumbar and lower thoracic area. While vertebral height was identical in both groups, vertebral depth was reduced in the GFSI-treated group. Reduced vertebral depth and altered vertebral morphology should be considered before instrumenting the spine in previously treated scoliotic SMA children.
Level of evidence III
Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.
Study design
Prospective multi-center study.
Objective
The study aimed to evaluate the accuracy of pedicle screw placement using a skin marker-based optical surgical navigation system for minimal ...invasive thoraco-lumbar-sacral pedicle screw placement.
Methods
The study was performed in a hybrid Operating Room with a video camera-based navigation system integrated in the imaging hardware. The patient was tracked with non-invasive skin markers while the instrument tracking was via an on-shaft optical marker pattern. The screw placement accuracy assessment was performed by three independent reviewers, using the Gertzbein grading. The screw placement time as well as the staff and patient radiation doses was also measured.
Results
In total, 211 screws in 39 patients were analyzed for screw placement accuracy. Of these 32.7% were in the thoracic region, 59.7% were in the lumbar region, and 7.6% were in the sacral region. An overall accuracy of 98.1% was achieved. No screws were deemed severely misplaced (Gertzbein grading 3). The average time for screw placement was 6 min and 25 secs (± 3 min 33 secs). The average operator radiation dose per subject was 40.3 µSv. The mean patient effective dose (ED) was 11.94 mSv.
Conclusion
Skin marker-based ON can be used to achieve very accurate thoracolumbarsacral pedicle screw placements.
Background In pediatric orthopedics, long bone lengthening procedures are routinely performed using manual, motorized or magnetically controlled implants. This study aims to prove expansion of a ...newly designed osmotic pump prior to long bone lengthening in living organisms and to rule out any complications related to in vivo conditions, such as congestion of the semipermeable membrane, local infection, or lack of water to drive the osmotic pump, as well as to compare in vivo and in vitro expansion data. Methods Osmotic pumps, which were designed to distract a plate osteosynthesis, were inserted in the dorsal paraspinal musculature of four piglets. To compare the performance of the pumps in in vivo and in vitro conditions, another set of pumps was submerged in physiologic saline solution at different temperatures. The lengthening progress was measured radiographically and sonographically in the study animals. Results Both, in vitro and in vivo tested osmotic pumps started distraction after an intended rest phase of four days and distracted evenly over the following twelve days. No complications, clogging or damages occurred. However, we observed a temperature dependency of the distraction rate ranging from 0.98 mm/day at 39°C to 1.10 mm/day at 42°C. With a second setup, we confirmed that the distraction rate differed by 72% within a measured temperature interval of 14° C. Conclusions The data presented here confirm that the novel osmotic pump showed comparable lengthening characteristics in vivo and in vitro. No complications, such as congestion of the semipermeable membrane, local infection, or lack of water to drive the osmotic pump were observed. Thus, osmotic pumps may have great potential in future applications such as long bone lengthening procedures, where continuous distraction probably provides a better bone quality than intermittent lengthening procedures. The fact that one pump failed to elongate in each condition, highlights the importance of technical improvement, but also demonstrates that this was not due to different circumstances within the in vivo or in vitro condition.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Crossfit athletes consistently recruit or transfer high levels of repetitive forces through the spine, and MRI has documented a higher rate of intervertebral disc degeneration in athletes compared ...with matched controls. The aim of this study was to evaluate early degenerative spinal disc changes in elite female CrossFit athletes quantified by 3.0 Tesla magnetic resonance imaging (MRI) matched with female none-athletes.
In a cross-sectional single-center study 19 asymptomatic adult participants, nine German female elite Crossfit athletes and ten female participants underwent spinal MRI (3.0T). Demographic data, spinal clinical examination results and sport-specific performance parameters were collected prior to the MRI. The primary outcome was the prevalence of degenerative spinal disc changes. The secondary outcome was the grade of degeneration using Pfirrmann grading.
A total of 437 discs underwent spinal MRI (3.0T). The prevalence of early degenerative disc disease was not increased. Pfirrmann degenerative grade did not show significant differences among groups.
Asymptomatic female elite Crossfit athletes do not show an increased prevalence of degenerative disc disease. Compared to a sex-matched control group, high training volume in Crossfit does not correlate to a higher incidence of degenerative disc changes in young females.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The anterior ilioinguinal and the posterior Kocher-Langenbeck approach have long been the standard surgical approaches to the acetabulum. The last decade has witnessed the development of so-called ...intrapelvic approaches for anterior pathologies because they provide better exposure of the quadrilateral plate. Currently, the modified Stoppa approach and the pararectus approach are frequently used by surgeons for the treatment of acetabular fractures. We investigated an even more direct access to the entire anterior column and the quadrilateral plate via the abdominal wall muscles, between the incisions for the ilioinguinal and the pararectus approach.After intensive study of anatomic specimens, a cadaver dissection was performed prior to clinical application. The approach was then used in 20 patients who were assessed retrospectively.Postoperative CT scans showed that, according to the Matta scoring system, the quality of fracture reduction was "anatomical" (≤ 1 mm) in 12 (60%), "imperfect" (2-3 mm) in four (20%), and "poor" (> 3 mm) in four (20%) patients. Numerous minor complications were observed; the majority of these had resolved at the time of discharge.In conclusion, the anterior transmuscular intrapelvic approach (ATI) is a safe and effective alternative to the ilioinguinal and pararectal approaches, and may be regarded as an evolutionary advancement of traditional procedures.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Objectives
To compare intraoperative 3D fluoroscopy with a ceiling-mounted flat panel detector in plate osteosynthesis of distal radius fractures (AO/OTA 2R3C1.2) with volar locking plate ...systems to conventional 2D fluoroscopy for detection of insufficient fracture reduction, plate misplacement and protruding screws.
Methods
Using a common volar approach on 12 cadaver forearms, total intraarticular distal radius fractures were induced, manually reduced and internally fixated with a 2.4 distal radius locking compression plate. 2D (anterior-posterior and lateral) and 3D (rotational) fluoroscopic images were taken as well as computed tomographies. Fluoroscopic images, Cone Beam CT (CBCT), 360° rotating sequences (so called “Movies”) and CT scans were co-evaluated by a specialist orthopedic surgeon and a specialist radiologist regarding quality of fracture reduction, position of plate, position of the three distal locking screws and position of the three diaphyseal screws. In reference to gold standard CT, sensitivity and specifity were analyzed.
Results
“Movie” showed highest sensitivity for detection of insufficient fracture reduction (88%). Sensitivity for detection of incorrect position of plate was 100% for CBCT and 90% for “Movie.” For intraarticular position of screws, 2D fluoroscopy and CBCT showed highest sensitivity and specifity (100 and 91%, respectively). Regarding detection of only marginal intraarticular position of screws, sensitivity and specifity of 2D fluoroscopy reached 100% (CBCT: 100 and 83%). “Movie” showed highest sensitivity for detection of overlapping position of screws (100%). When it comes to specifity, CBCT achieved 100%. Regarding detection of only marginal overlapping position of screws, 2D fluoroscopy and “Movie” showed highest sensitivity (100%). CBCT achieved highest specifity (100%).
Conclusion
As for assessment of quality of fracture reduction and detection of incorrect position of plate as well as overlapping position of the three diaphyseal screws CBCT and “Movie” are comparable to CT – especially when combined. Particularly sensitivity is high compared to standard 2D fluoroscopy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Adjuvant therapy in autologous chondrocyte implantation (ACI) can control the post-traumatic environment and guide graft maturation to support cartilage repair. To investigate both aspects, we ...examined potential chondro-regenerative effects of lysed platelet concentrate (PC) and supplementary interleukin 10 (IL-10) on mechanically injured cartilage and on clinically used ACI scaffolds. ACI remnants and human cartilage explants, which were applied to an uniaxial unconfined compression as injury model, were treated with human IL-10 and/or PC from thrombocyte concentrates. We analyzed nuclear blebbing/TUNEL, sGAG content, immunohistochemistry, and the expression of COL1A1, COL2A1, COL10A1, SOX9, and ACAN. Post-injuriously, PC was associated with less cell death, increased COL2A1 expression, and decreased COL10A1 expression and, interestingly, the combination with Il-10 or Il-10 alone had no additional effects, except on COL10A1, which was most effectively decreased by the combination of PC and Il-10. The expression of COL2A1 or SOX9 was statistically not modulated by these substances. In contrast, in chondrocytes in ACI grafts the combination of PC and IL-10 had the most pronounced effects on all parameters except ACAN. Thus, using adjuvants such as PC and IL-10, preferably in combination, is a promising strategy for enhancing repair and graft maturation of autologous transplanted chondrocytes after cartilage injury.
Missed or underestimated injuries are one of the central problems in trauma care. Foot injuries can easily be missed because they lay beyond the regularly screened field of a trauma computer ...tomography scan (CT scan). During primary and secondary survey a careful examination of the extremities often becomes of secondary interest in the severely injured patient.
Thirty-four thousand ninety-one multiple trauma patients of the TraumaRegister DGU® were evaluated from 2002 to 2014. We differentiated between patients with foot injuries, patients with missed foot injuries and patients without foot injuries. Included were ankle fractures, calcaneus fractures, talus fractures, metatarsal fractures, toe fractures, amputation, soft tissue injuries and/or ligamentous injuries.
Summarized evaluation of 34,091 trauma patients showed a share of 2532 patients with foot injuries. Time of diagnosis was documented in 2199 cases. 2055 patients had early diagnosed foot injuries and 144 patients had initially missed foot injuries. Missed foot injuries were especially found in patients with car accidents or fall from ≥3 m. Patients with higher Abbreviated Injury Scale (AIS) or lower Glasgow Coma Scale (GCS) were not significantly more affected by missed foot injuries. Missing foot injuries was also not caused by injury severity or higher age.
Our data highlights the need of careful evaluation of the feet during primary and secondary survey particularly when a tibia or femur fracture is diagnosed. Special attention should be turned to patients after car accidents or fall from great height. Suicide victims also need major attention. Patients with early operations also need careful examination and tertiary survey is highly recommended.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The use of virtual reality trainers for teaching minimally invasive surgical techniques has been established for a long time in conventional laparoscopy as well as robotic surgery. The aim of the ...present study was to evaluate the impact of reproducible disruptive factors on the surgeon's work. In a cross-sectional investigation, surgeons were tested with regard to the impact of different disruptive factors when doing exercises on a robotic-surgery simulator (Mimic Flex VR
). Additionally, we collected data about the participants' professional experience, gender, age, expertise in playing an instrument, and expertise in playing video games. The data were collected during DRUS 2019 (Symposium of the German Society for Robot-assisted Urology). Forty-two surgeons attending DRUS 2019 were asked to participate in a virtual robotic stress training unit. The surgeons worked in various specialties (visceral surgery, gynecology, and urology) and had different levels of expertise. The time taken to complete the exercise (TTCE), the final score (FSC), and blood loss (BL) were measured. In the basic exercise with an interactive disruption, TTCE was significantly longer (
< 0.01) and FSC significantly lower (
< 0.05). No significant difference in TTCE, FSC, or BL was noted in the advanced exercise with acoustic disruption. Performance during disruption was not dependent on the level of surgical experience, gender, age, expertise in playing an instrument, or playing video games. A positive correlation was registered between self-estimation and surgical experience. Interactive disruptions have a greater impact on the performance of a surgeon than acoustic ones. Disruption affects the performance of experienced as well as inexperienced surgeons. Disruption in daily surgery should be evaluated and minimized in the interest of the patient's safety.
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