Daniela Klitscher

Intramedullary nailing vs. palmar locked plating for unstable dorsally comminuted distal radius fractures: A biomechanical study

BACKGROUND The purpose of this study was to compare the stability of a 2.4mm palmar locking compression plate and a new intramedullary nail-plate-hybrid Targon DR for dorsally comminuted distal radius fractures. METHODS An extraarticular 10mm dorsally open wedge osteotomy was created in 8 pairs of fresh frozen human radii to simulate an AO-A3-fracture. The fractures were stabilized using one of the fixation methods. The specimens were loaded axially with 200 N and dorsal-excentrically with 80 N. 2000cycles of dynamic loading and axial loading-to-failure were performed. FINDINGS Axial loading revealed that intramedullary osteosynthesis (Targon DR: 369 N/mm) was significantly (p=0.017) stiffer than plate osteosynthesis (Locking compression plate: 131 N/mm). With 214 N/mm the intramedullary nail also showed higher stability during dorsal excentric loading than the Locking compression plate with 51 N/mm (p=0.012). After 2000 cycles of axial loading with 80 N the Targon DR-group was significantly stiffer than the Locking compression plate-group under both loading patterns. Neither group showed significant changes in stiffness after 2000 cycles. Under dorsal excentric loading the Targon DR-group was still significantly stiffer with 212 N/mm than the Locking compression plate-group with 45 N/mm (p=0.012). The load to failure tests demonstrated higher stability of intramedullary nailing (625 N) when compared to plate osteosynthesis (403 N) (p<0.025). INTERPRETATION The study shows that intramedullary fixation of a distal AO-A3 radial fracture is biomechanically more stable than volar fixed-angle plating under axial and dorsal-excentric loading in an experimental setup.

Locking Plates for Corrective Osteotomy of Malunited Dorsally Tilted Distal Radial Fractures: A Biomechanical Study

The purpose of the study was to compare the biomechanical properties of five different palmar fixation plate designs in a distal radius osteotomy cadaver model. A 1 cm metaphyseal osteotomy gap was made to simulate a corrective osteotomy and the osteotomy plated. Axial load was applied to the distal end of each construct by a material testing machine under control of a motion analysis video system. The specimens were arranged into five implant groups of eight specimens each. No test group developed deformity and movement of the fracture gap greater than 2 mm with a load of 100 N. Increasing the load to 250 N revealed statistically significant differences in stiffness and failure load between the different plates. Axial failure strength and stiffness were greater for the radial correction plates than for the other implants. The former may provide enough stability for corrective osteotomy of dorsally angulated distal radial malunions, even when the osteotomy gap is only filled with cancellous bone graft instead of cortical bone graft.

Evaluation of severely displaced radial neck fractures in children treated with elastic stable intramedullary nailing.

Background We performed a retrospective case study of 28 consecutive severely displaced radial neck fractures (Judet types III and IV) in children treated with elastic stable intramedullary nailing using the Metaizeau technique. Methods We reviewed all preoperative radiographs and classified the injuries according to Judet. All patients were asked to return for later assessment. They underwent physical examination; radiographs were taken; and they were asked for subjective assessment. An evaluation of clinical results was performed using the Mayo Elbow Performance Score (MEPS). Results According to Judet classification there were 13 type III and 15 type IV fractures. Using the MEPS, excellent results were achieved in 23 cases (82%) and good results in 5 cases (18%). The average MEPS was 97 points. Five patients complained of mild pain. Three malunions were observed. Conclusions Elastic stable intramedullary nailing is a minimally invasive technique, allowing stable fixation and providing excellent to good outcomes with a low complication rate. Level of Evidence We performed a retrospective level 4 study of case series.

Biomechanische Studie zu vier winkelstabilen distalen palmaren Radiusplatten und einer nichtwinkelstabilen Radiusplatte: Steifigkeit und Versagenstests am Kadavermodell / Biomechanical study of four palmar locking plates and one non-locking palmar plate for distal radius fractures: stiffness and load to failure tests in a cadaver model

Zusammenfassung Fünf unterschiedliche Plattensysteme zur Versorgung von distalen Radiusfrakturen über einen palmaren Zugang wurden im biomechanischen Kadavermodell untersucht. Dazu wurde eine 1 cm breite metaphysäre Osteotomie unmittelbar proximal zum Gelenkspalt durchgeführt und die jeweilige Platte entsprechend den Anweisungen des Herstellers fixiert. Unter axialer Belastung wurde das Konstrukt dann in einer pneumatisch angetriebenen Testmaschine (Sincotec) geprüft. Jedes Implantatsystem wurde an jeweils 8 Leichenknochen bezüglich der Steifigkeit gemessen. Keines der Konstrukte zeigte Deformitäten im Osteotomiespalt von über 2 mm unter Lasten bis zu 100 N. Bei Lasten bis zu 250 N stellten sich signifikante Differenzen bezüglich der Steifigkeit und der Versagenscharakteristika der unterschiedlichen Plattensysteme dar. Die mittlere Steifigkeit unter axialer Belastung (MW±SD) betrug 356,4±138,6 N/mm für die Radiuskorrekturplatte ohne lateralen Ausläufer, 299,7±86,3 N/mm für die Radiuskorrekturplatte mit lateralem Ausläufer, 132,8±41,5 N/mm für die distale volare Radiusplatte, 112,5±40,2 N/mm für die 3,5 mm Titan Locking-Compression-Platte und 91,9±29,2 N/mm für die 3,5 mm Standard T-Platte. Dabei zeigte das nichtwinkelstabile Implantat (STP-Platte) die geringste Steifigkeit. Unerwartet gab es Differenzen von über 100% bezüglich der Steifigkeit zwischen den auf den ersten Blick weitgehend ähnlich erscheinenden winkelstabilen Implantaten. Zusätzlich erfolgte die Auswertung der in der Literatur beschriebenen Ergebnisse von biomechanischen Untersuchungen bei der distalen Radiusfraktur. Abstract Five different palmar fixation plate designs were compared in a distal radial osteotomy cadaver model with regard to their biomechanical properties. A metaphyseal osteotomy gap of 1 cm was performed and the osteosynthesis was plated according to the manufacturers instructions. Axial load was applied to the construct by a pneumatic material testing machine. Five implant groups with eight cadavers each were tested concerning stiffness. None of the constructs developed deformity and movement of the fracture gap larger than 2 mm with a load of 100 N. Increasing the load to 250 N revealed significant differences in stiffness and failure load between the different plates. The mean stiffness under axial load (mean±standard deviation) was 356.4± 138.6 N/mm for the radius correction plate without lateral tongue, 299.7±86.3 N/mm for the radius correction plate with lateral tongue, 132.8±41.5 N/mm for the distal volar radius plate, 112.5±40.2 N/mm for the 3.5 mm titanium locking compression plate and 91.9±29.2 N/mm for the standard stainless steel 3.5 mm T-Plate. The non-angular stable implant (STP plate) had the lowest stiffness. Unexpectedly, there were differences over 100% concerning the stiffness between the at first glance nearly similar angular stable implants. Additionally, a review of the literature concerning biomechanical investigations of the distal radial fracture was performed.

Are there any differences in various polyaxial locking systems? A mechanical study of different locking screws in multidirectional angular stable distal radius plates.

Abstract Numerous angular stable plates for the distal radius exist, and technically based comparisons of the polyaxial locking interfaces are lacking. The aim of this mechanical study was to investigate three different locking interfaces of angular stable volar plates by cantilever bending: VA-LCP Two-Column Distal Radius Plates 2.4 mm (Synthes® GmbH, Oberdorf, Switzerland), IXOS® P4 (Martin, Tuttlingen, Germany) and VariAX™ (Stryker®, Duisburg, Germany). We assessed the strength of 0°, 5°, 10° and 15° screw locking angles and tested the bending strength from 10° to 5° angles by cyclic loading until breakage. The final setup repeated the above assessments by inclusion of four locking screws. The single screw-plate interfaces of the VA-LCP showed the highest bending moment at an angle of 0° and 5°, the IXOS® P4 at an angle of 10° and 15° and the VariAX™ when changing the insertion angle from 10° into 5°. The strength of polyaxial locking interfaces and mechanism of failure proved to be different among the examined plates.

Volar fixed-angle plating of distal radius fractures: screws versus pegs--a biomechanical study in a cadaveric model.

Objectives: The purpose of this biomechanical study was to determine whether a multidirectional fixed-angle plate with locking screws or with locking pegs in the distal fragment would optimize fixation of Orthopaedic Trauma Association (OTA) type A3 distal radius fractures. Methods: Eight pairs of fresh–frozen human distal radii were used. Extra-articular distal radius fractures were created and stabilized with a multidirectional volar fixed-angle plate. The radii were randomized into 2 matched-paired groups. The distal fragment in Group I was stabilized with 7 locking screws. The distal fragment in Group II was fixed with 7 locking pegs. The proximal fragment in both groups was fixed with 3 screws. The specimens were tested under torsion and axial compression during static and cyclic tests. Finally, load-to-failure tests were performed under torsion. Results: After 1000 cycles, 99% of the median torsional stiffness remained in the group using screws, whereas only 76% of the median stiffness under torsion remained in the group using pegs (P = 0.018). Under axial compression, median stiffness remained at 93% in the group using screws after 1000 cycles compared with a median of 0% in the group using pegs (P = 0.018). Conclusions: This biomechanical study showed a statistically significant difference between the locking screw and locking smooth peg configuration with regard to stiffness of the constructs after 1000 cycles. The use of locking screws as opposed to smooth locking pegs for OTA type A3 extra-articular distal radius fractures optimizes construct stability.

Pediatric fractures of the carpal scaphoid: a retrospective clinical and radiological study.

A retrospective study was undertaken of 22 carpal scaphoid fracture patients younger than 18 years. Of these, 17 patients received conservative treatment, and 5 received treatment involving screw fixation with or without a bone graft from the iliac crest. Clinical outcomes were evaluated using the Cooney score. Radiographs were analyzed with respect to the site of the fracture, the course of the fracture gap, displacement, and time to union. According to the Cooney score, in 94% of patients, good or excellent results were obtained. A total of 94% of patients considered their result as good or excellent. All fractures healed. Malunion was evident in 1 case.

MRT-induzierte Verbrennung bei Tätowierungen

ZusammenfassungVerbrennungen bei Patienten mit Tätowierungen stellen eine selten beschriebene Komplikation infolge von MRT-Untersuchungen dar. Im Rahmen unfallchirurgischer Diagnostik wird das MRT zunehmend auch bei Unfallpatienten eingesetzt.In diesem Beitrag wird der Fall eines Patienten nach Wirbelsäulentrauma vorgestellt, bei dem brennende Schmerzen im Bereich einer Tätowierung am distalen Femur zum Abbruch der MRT-Diagnostik geführt haben. Anhand dieses Beispiels werden mögliche Pathomechanismen MRT-induzierter Verbrennungen bei Tätowierungen diskutiert.Es wird deutlich, dass Patienten vor einer MRT gezielt nach Tätowierungen zu fragen und über möglich Schmerzempfindungen aufzuklären sind.AbstractSkin burns to patients with tattoos during MRI procedures are reported but rare complications. MRI scans are being used more often also as diagnostic procedures in trauma patients.In this article we present the case of a patient after trauma of the vertebral column who experienced burning pain at the site of a tattoo on the distal femur during the MRI examination, necessitating cessation of this procedure. Based on this example we discuss possible pathomechanisms of MRI-induced skin burns to patients with tattoos.It becomes clear that patients have to be asked about possible tattoos before MRI scans and should be informed about possible pain development.

[MRT-induced burns in tattooed patients. Case report of an traumatic surgery patient].

ZusammenfassungVerbrennungen bei Patienten mit Tätowierungen stellen eine selten beschriebene Komplikation infolge von MRT-Untersuchungen dar. Im Rahmen unfallchirurgischer Diagnostik wird das MRT zunehmend auch bei Unfallpatienten eingesetzt.In diesem Beitrag wird der Fall eines Patienten nach Wirbelsäulentrauma vorgestellt, bei dem brennende Schmerzen im Bereich einer Tätowierung am distalen Femur zum Abbruch der MRT-Diagnostik geführt haben. Anhand dieses Beispiels werden mögliche Pathomechanismen MRT-induzierter Verbrennungen bei Tätowierungen diskutiert.Es wird deutlich, dass Patienten vor einer MRT gezielt nach Tätowierungen zu fragen und über möglich Schmerzempfindungen aufzuklären sind.AbstractSkin burns to patients with tattoos during MRI procedures are reported but rare complications. MRI scans are being used more often also as diagnostic procedures in trauma patients.In this article we present the case of a patient after trauma of the vertebral column who experienced burning pain at the site of a tattoo on the distal femur during the MRI examination, necessitating cessation of this procedure. Based on this example we discuss possible pathomechanisms of MRI-induced skin burns to patients with tattoos.It becomes clear that patients have to be asked about possible tattoos before MRI scans and should be informed about possible pain development.

Biomechanical Comparison of Dorsal Nail Plate Versus Screw and K-Wire Construct for Extra-Articular Distal Radius Fractures in a Cadaver Bone Model

PURPOSE The purpose of the study was to compare the biomechanical stability of distal radius fracture fixation with 2 new implants, the DNP (Hand Innovations LLC, Miami, FL), a dorsal locked hybrid of nail and plate, and the XSCREW (Zimmer, Freiburg, Germany), an implant combining a cannulated screw and K-wires, in a cadaver bone distal radius fracture model. METHODS Eight pairs of fresh-frozen cadaver radii were used. To simulate an extra-articular distal radius fracture, a 5-mm volar open wedge osteotomy was made. Axial loads of 10 to 100 N and torque loads of -1.5 to 1.5 Nm were applied by a testing machine to the intact radii and to the radii after each device was fixed as recommended by the manufacturer. One thousand cycles in torque and failure tests were performed. RESULTS With a median of 136.0 N/mm, the axial stiffness of XSCREW-fixed specimens was higher than that of DNP-fixed specimens, with a median of 69.5 N/mm, but differences were not statistically significant. With a median of 0.163 Nm/ degrees , the torque stiffness of XSCREW-fixed specimens was significantly higher than that of DNP-fixed specimens, with a median of 0.068 Nm/ degrees . The XSCREW-group reached 33% of the axial stiffness and 49% of the torque stiffness of the intact radii, and the DNP-group reached 14% of the axial stiffness and 20% of the torque stiffness of the intact radii. CONCLUSIONS In this human cadaver bone biomechanical study, the XSCREW provided more stability than the DNP in torque stiffness but not in axial stiffness.