R. Grass

Impact of helicopter transport and hospital level on mortality of polytrauma patients.

BACKGROUND Despite numerous studies analyzing this topic, specific advantages of helicopter transport of blunt polytrauma patients as compared with ground ambulances have not yet been identified unequivocally. METHODS Four possible pathways in 403 polytrauma patients (Injury Severity Score [ISS] > 16) who were in reach of the helicopter emergency medical service (HEMS) Dresden were analyzed as follows: HEMS-UNI group (n = 140), transfer by HEMS into a university hospital; AMB-REG group (n = 102), transfer by ground ambulance into a regional (Level II or III) hospital; AMB-UNI group (n = 70), transfer by ground ambulance into the university hospital; and INTER group (n = 91), transfer by ground ambulance into a regional hospital, followed by transfer to the university hospital. Scores used were the ISS and the TRISS. Tests used for statistical analysis included chi2 and Fishers tests. Statistical significance was set at p > 0.05. RESULTS Age, gender, and mean ISS (range, 33.3-35.6) revealed extensive homogeneity of the groups. Mortality of the AMB-REG group was almost doubled (41.2%) compared with HEMS-UNI (22.1%) patients (p = 0.002). The AMB-UNI group displayed the lowest mortality (15.7%, p = not significant). TRISS analysis (PRE-Chart) revealed identical outcome for AMB-UNI and HEMS-UNI patients. Rescue time averaged 90 +/- 29 minutes for HEMS-UNI patients, 68 +/- 25 minutes for AMB-UNI patients, and 69 +/- 26 minutes for the AMB-REG group. CONCLUSION Primary transfer by HEMS into a Level I trauma center reduces mortality markedly. In principle, this benefit can be attributed to superior preclinical therapy, primary admission to a Level I trauma center, or both. However, the identical probability of survival of the AMB-UNI and HEMS-UNI groups in this and comparable studies does not confirm generally better survival rates on account of a more aggressive on-site approach.

Peroneus longus ligamentoplasty for chronic instability of the distal tibiofibular syndesmosis.

The distal tibiofibular syndesmosmotic ligament complex is important for dynamic stability and congruency of the ankle joint. Syndesmotic lesions in the ankle fracture-dislocations are well recognized and classified systematically. Chronic insufficiency of the syndesmosis leads to a lateral shift of the talus and under eversion stress permits a pathological rotation of the talus. There is also retroversion of the distal fibula representing a painful deformity. Little experience exists with surgical reconstruction of the syndesmosis. This article describes a new ligamentoplasty with a split peroneus longus tendon graft that mimics the normal anatomic conditions of the syndesmotic complex in 16 patients with symptomatic chronic syndesmotic insufficiency after pronation-external rotation and pronation abduction injuries to the ankle joint. Postoperatively, no infections or hematomas were seen. One patient had asymptomatic breakage of the syndesmosis screw; one patient had a 10° decrease of dorsiflexion at the ankle because of a partial anterior tibiofibular synostosis. Fifteen of 16 patients had pain relief at a mean follow-up period of 16.4 months (range, 13–29 months); all patients had relief of the chronic swelling of the ankle and the giving way. The mean Karlsson score at follow-up was 88 (range, 70–100) points. It may be concluded that peroneus longus ligamentoplasty in a preliminary series resulted in reliable ankle stability and considerable pain relief in patients with chronic syndesmotic instability.

Verletzungen der unteren tibiofibularen Syndesmose

ZusammenfassungDie Inzidenz isolierter distaler tibiofibularer Syndesmosenrupturen beträgt 1–11% aller Distorsionstraumen des oberen Sprunggelenks (OSG). Diese Verletzungen werden häufig übersehen, mit einer anterolateralen Rotationsinstabilität des OSG verwechselt und fallen häufig erst durch einen protrahierten Behandlungsverlauf auf.Obwohl seit der systematischen Beschreibung von Luxationsfrakturen des OSG durch Weber u. Lauge-Hansen die Pathomechanik und das Ausmaß von begleitenden Rupturen des distalen Syndesmosenkomplexes bekannt sind, liegen keine klaren Richtlinien vor, wann die häufig unterschätzte, komplexe Pathologie des Bandkomplexes der Luxationsfraktur einer operativen Therapie bedarf, um neben einer achsen- und längengerechten Ausheilung der Malleolarfraktur auch eine suffiziente und funktionsgerechte Ausheilung des distalen Syndesmosenkomplexes zu erreichen. Auch gibt es bislang keine systematischen Untersuchungen, die sich bei der Verlaufsbeurteilung nach Malleolarfrakturen der speziellen Problematik der Syndesmosenfunktion annehmen, obwohl seit langem bekannt ist, dass eine tibiofibulare Diastase, wie sie bei einer chronischen Syndesmoseninstabilität vorliegt, zu einer pathologischen Außenrotation des Talus führt. In Verbindung mit der Valgisationstendenz des Sprungbeins kommt es zudem zu einer Verminderung des Kontaktes der artikulären Gelenkflächen und damit zu einer präarthrotischen Deformität.Die Standardverfahren der klinischen, röntgenologischen und computertomographischen Evaluierung akuter und chronischer Syndesmoseninsuffizienzen werden vorgestellt sowie auf die Technik, Bedeutung und Komplikationsmöglichkeiten der operativen Versorgung der frischen Syndesmosenruptur, die im Rahmen von Luxationsfrakturen des OSG gesehen werden, hingewiesen. Operative Korrekturen der chronischen Syndesmoseninsuffizienz wurden bislang selten beschrieben.Neben der Arthrodesierung der Syndesmose, der Rekonstruktion mit Kunstbändern, wurde von Castaing eine Tenodese mit der Sehne des M. peronaeus brevis vorgeschlagen. Eine dauerhafte Rekonstruktion des distalen Syndesmosenkomplexes muss neben einer suffizienten Gabelführung den komplexen Bewegungsablauf der Fibula in der Incisura tiobiofibularis, der bei der Begrenzung der Talusrotation von immenser Wichtigkeit ist, berücksichtigen. Aus diesem Grund wurde im eigenen Vorgehen bei symptomatischer Syndesmoseninsuffizienz das von Castaing entwickelte Verfahren dahingehend modifiziert, dass neben dem Ersatz der Ligg. tibiofibulare anterius und posterius das Lig. tibiofibulare interosseum anatomisch rekonstruiert wird.Das eigene Verfahren erscheint, da es im Gegensatz zu dem Castaing-Verfahren eine 3-Punkt-Fixierung der Fibula beinhaltet, der Anatomie besser angepasst und biomechanisch vorteilhaft. Die operative Technik der Syndesmosenplastik wird vorgestellt. AbstractThe incidence of isolated distal tibiofibular syndesmotic ruptures in acute ankle sprains lies between 1% and 11%. These injuries are frequently overseen or misdiagnosed as anterolateral rotational instability of the ankle and often become apparent through protracted courses. Although the pathomechanics and extent of syndesmotic injuries have been systematically described by Lauge-Hansen and Weber, no generally accepted guidelines exist as to when these complex injuries are to be treated surgically to ensure sufficient and stable healing of the syndesmosis besides correct alignment of the distal fibula. So far, systematic follow-up regarding syndesmotic injuries in ankle fractures is missing, although it has long been recognized that tibiofibular diastasis secondary to chronic syndesmotic instability leads to external rotation of the talus. In combination with a valgus position of the talus, this instability leads to a decrease in the contact area which results in posttraumatic arthritic changes. This paper reviews the standard diagnostic and therapeutic procedures for acute syndesmotic ruptures in fracture dislocations of the ankle.Among the few corrective procedures advocated for chronic syndesmotic insufficiency are tibiofibular arthrodesis, synthetic ligament substitutes, and tenodesis with the peroneus brevis tendon. A sufficient reconstruction must restore the stability of the ankle mortise and alignment of the fibula in the tibiofibular incisura to ensure limitation of talar rotation. Therefore, a tenodesis was developed which substitutes the three important ligaments of the syndesmotic complex. The Castaing procedure for chronic syndesmotic insufficiency was modified with reconstruction of the interosseous tibiofibular ligament in addition to the anterior and posterior tibiofibular ligaments. The resulting three-point fixation of the distal fibula appears more anatomically, physiologically, and biomechanically advantageous. The operative procedure is given in detail. Distal tibiofibular syndesmosis · Persistent instability of the distal syndesmosis · Ankle fractures · Syndesmotic screw

Improved intramedullary nail interlocking in osteoporotic bone

Objective Intramedullary nail locking bolts often fail to gain purchase or cut out in osteoporotic bone. The biomechanical stability of a bladelike device that lowers intraosseous stress levels by distributing the load over a greater volume of bone was compared with conventional locking bolts in osteoporotic bone. Methods Standardized simulated comminuted supracondylar femoral fractures (segmental defect) in fresh-frozen paired osteoporotic (bone mineral density <200 milligrams per cubic centimeter) human cadaveric femurs were stabilized with a retrograde unreamed distal femoral nail and distally interlocked with conventional locking bolts or a bladelike device. The distal portions of the fixator–bone constructs were tested under axial load, and the stiffness and strength were compared (pairwise). Results Interlocking with a bladelike device was 41 percent stiffer (p = 0.01) and 20 percent stronger (p = 0.02) than that with conventional locking bolts. All posttesting radiographs showed compaction of the cancellous bone distal to the interlocking devices. Even after nail displacements of twelve millimeters, only a few locking bolts were plastically deformed and no bladelike device showed gross plastic deformation. Conclusion This study showed the biomechanical benefits of increasing the bone–implant interface surface for improving the acute stiffness and strength of fracture fixation in osteoporotic cancellous bone. The fixator–bone construct withstood higher forces before failure in these fragile bones.

Internal fixation of supracondylar femoral fractures : Comparative biomechanical performance of the 95-degree blade plate and two retrograde nails

OBJECTIVE The biomechanical stability of supracondylar femoral fractures fixed with a condylar blade plate (plate), a Green Seligson Henry nail (GSHN), or a new retrograde unreamed supracondylar femoral nail (new nail) based on the AO unreamed femoral nail were compared. DESIGN A standardized simulated comminuted supracondylar femoral fracture (segmental defect) in fresh frozen paired cadaveric femora was stabilized with one of the implants. The interfragmentary fracture site stiffness in three directions and axial strength of the fixator-bone construct were compared (pairwise). RESULTS The plate versus the new nail was (a) axially 10 percent as stiff and 50 percent as strong (ultimate strength), (b) as stiff in A/P bending, and (c) five times more stiff in torsion. Varus angle at failure under axial load was significantly greater for the plate than for the new nail. There were no statistical differences in axial stiffness and ultimate strength between the new nail and the GSHN, but the new nail was 50 percent and 30 percent as stiff in A/P bending and torsion, respectively. The magnitude of deformation at failure under axial loading was similar. CONCLUSIONS In fixation of extraarticular comminuted supracondylar distal femur fractures, results indicate that (a) the new nail provides equal or greater stability than does the plate, except when large torsional loads are anticipated, and (b) the new nail provides stability equal to the GSHN for axial loading and lesser stability against off-axis loads. As is evident in this and other studies, intramedullary implants are less torsionally stiff than are plates. The torsional stiffness of the new nail is expected to be sufficient because it is comparable to many available nails, and low torsional moments are expected for healing femoral supracondylar fractures.

In vivo effects of modification of hydroxyapatite/collagen composites with and without chondroitin sulphate on bone remodeling in the sheep tibia

The addition of chondroitin sulphate (CS) to bone cements with calcium phosphate has lead to an enhancement of bone remodeling and an increase in new bone formation in small animals. The goal of this study was to verify the effect of CS in bone cements in a large animal model simulating a clinically relevant situation of a segmental cortical defect of a critical size on bone–implant interaction and bone remodeling. The influence of adding CS to hydroxyapatite/collagen (HA/Col) composites on host response was assessed in a standard sheep tibia model. A midshaft defect of 3 cm was created in the tibiae of 14 adult female sheep. The defect was filled with a HA/Col cement cylinder in seven animals and with a CS‐modified hydroxyapatite/collagen (HA/Col/CS) cement cylinder in seven animals. In all cases the tibia was stabilized with an interlocked universal tibial nail. The animals in each group were analyzed with X‐rays, CT scans, histology, immunohistochemistry, and enzymehistochemistry, as well as histomorphometric measurements. The X‐ray investigation showed a significantly earlier callus reaction around the HA/Col/CS implants compared to HA/Col alone. The amount of newly formed bone at the end point of the experiment was significantly larger around HA/Col/CS cylinders both in the CT scan and in the histomorphometric analysis. There were still TRAP‐positive osteoclasts around the HA/Col implants after 3 months. The number of osteopontin‐positive osteoblasts and the direct bone contact were significantly higher around HA/Col/CS implants. We conclude that addition of CS enhances bone remodeling and new bone formation around HA/Col composites.

Ligamentous injuries about the ankle and subtalar joints.

Ligamentous injuries at the ankle and subtalar joint range from simple sprains to severe talar dislocations. While lateral ankle sprains are among the most frequently encountered injuries and do not pose a greater diagnostic problem, the surgeon must be suspicious not to overlook associated ligamentous injuries at the subtalar and midtarsal level that may result in chronic painful conditions. Syndesmotic instabilities with or without ankle fractures must be assessed carefully and treated properly, since these are prearthrotic conditions. In the treatment of chronic ankle or subtalar instability tenodeses provide mechanical stability while reducing subtalar mobility. Anatomic reconstruction methods therefore should be considered for both conditions.

Probleme und Kontroversen in der Behandlung von Sprunggelenkfrakturen

Ankle fractures are the most frequent injuries of a load-bearing joint. Their treatment belongs to the daily routine in trauma surgery. However, despite an increased understanding of the mechanism of injury and relatively straightforward fixation techniques, the medium- to long-term results are often less than satisfactory. The following article therefore explicitly focusses on unsolved problems and controversies in the treatment of ankle fractures in the light of the current literature. These include the therapeutic and prognostic relevance of frequently used classification systems, criteria for the indication for surgery, frequent hazards in internal fixation, the question of whether and how to fix the posterior malleolus, and the detection and treatment of syndesmotic instability. Furthermore, trauma surgeons face the increasing incidence of ankle fractures in the elderly. The presence of osteoporosis, diabetes mellitus and neuropathic osteoarthropathy represents a special challenge.ZusammenfassungSprunggelenkfrakturen sind die häufigsten Verletzungen eines lasttragenden Gelenks, ihre Versorgung gehört zur täglichen Routine im unfallchirurgischen Alltag. Trotz eines gestiegenen Verständnisses der Pathomechanismen und der vergleichweise einfachen Osteosynthesetechniken sind die mittel- und langfristigen Ergebnisse nicht immer zufriedenstellend. Der folgende Artikel widmet sich daher im Spiegel der aktuellen Literatur explizit den ungelösten Problemen und kontrovers diskutierten Fragen in der Sprunggelenkchirurgie. Dazu gehören die therapeutische und prognostische Relevanz der angewandten Klassifikationen, die Kriterien für die Indikationsstellung, häufige Probleme bei der operativen Versorgung, die Frage nach der Notwendigkeit und Technik der Versorgung der Tibiahinterkantenfrakturen sowie das Erkennen und Behandeln der Syndesmoseninstabilität. Ein im klinischen Alltag stetig zunehmendes Problem sind Sprunggelenkfrakturen bei älteren Patienten insbesondere mit vorliegender Osteoporose, Diabetes mellitus sowie einer neurogenen Osteoarthropathie.AbstractAnkle fractures are the most frequent injuries of a load-bearing joint. Their treatment belongs to the daily routine in trauma surgery. However, despite an increased understanding of the mechanism of injury and relatively straightforward fixation techniques, the medium- to long-term results are often less than satisfactory. The following article therefore explicitly focusses on unsolved problems and controversies in the treatment of ankle fractures in the light of the current literature. These include the therapeutic and prognostic relevance of frequently used classification systems, criteria for the indication for surgery, frequent hazards in internal fixation, the question of whether and how to fix the posterior malleolus, and the detection and treatment of syndesmotic instability. Furthermore, trauma surgeons face the increasing incidence of ankle fractures in the elderly. The presence of osteoporosis, diabetes mellitus and neuropathic osteoarthropathy represents a special challenge.

Stability of locking and non-locking plates in an osteoporotic calcaneal fracture model.

Background: The aim of this biomechanical cadaver study of calcaneal fractures was to investigate whether a locking calcaneal plate provides more stiffness in osteoporotic bone compared to a non-locking plate. Materials and Methods: Sixteen fresh frozen bone mineral density (BMD)-matched cadaver feet were tested in a four-part model of a Sanders Type IIB calcaneal fracture. The fractures were fixed either with a non-locking AO (Sanders) plate or an interlocking AO plate (Synthes, Paoli, PA) to the lateral calcaneal wall with six screws. Specimens were subjected to cyclic loading which was increased stepwise to full body weight. Displacement of the posterior facet fragment was measured with an optical tracking system in the sagittal and transverse planes. Results: No statistically significant differences were observed between the non-locking and the locking plates with respect to number of cycles to failure or 1-mm displacement of the posterior facet. The initial stiffness was significantly higher for non-locking plates. Conclusion: In osteoporotic bone, the greater stiffness of the screw-locking-plate construct was offset by the smaller diameter of the screw threads and the lower friction between the plate and bone when a locking plate was used. In clinical practice, the plate should first be compressed to osteoporotic bone with cancellous screws and at least two screws should be placed in the anterior process and in the tuberosity of the calcaneus.

Ankle arthrodesis after failed joint replacement

ZusammenfassungBericht über vier Patienten.OperationszielWiederherstellung einer schmerzfreien Funktion der unteren Extremität durch Arthrodese des oberen Sprunggelenks nach erfolgloser Endoprothese.IndikationenGelockerte oder infizierte Sprunggelenkendoprothese.KontraindikationenSchlechter Allgemeinzustand.Mangelnde Mitarbeit des Patienten.OperationstechnikEntfernung der Prothesenkomponenten. Auffüllen des Defekts mit trikortikalen Knochenspänen vom gleichseitigen Beckenkamm und interne Fixation. In Gegenwart von schleichenden Infektionen sind zwei Operationsschritte notwendig: erster Schritt: Entfernen der Komponenten, radikales Débridement und Auffüllen des Defekts mit PMMA-Kugelketten; zweiter Schritt: Arthrodese.ErgebnisseDas Operationsziel wurde bei zwei von vier Patienten komplikationslos erreicht. Ein Patient wies Zeichen einer verzögerten Heilung nach 18 Monaten auf, und der vierte benötigte eine Revision mit retrograd eingebrachtem distalen Femurnagel und eine autogene Spongiosaplastik, die den gewünschten Erfolg brachte.AbstractReport of four patients.ObjectiveRestoration of a painless gait through ankle arthrodesis after failed total ankle replacement.IndicationsLoosened or infected total ankle replacement.ContraindicationsPoor general health.Absent patient compliance.Surgical TechniqueRemoval of total joint components. Filling of the defect with tricortical bone grafts harvested from the ipsilateral iliac crest and internal fixation. In instances of suspected infection a two-stage procedure is recommended, the first stage consisting of a removal of the components, a meticulous debridement, and filling of the defect with gentamycin-laden PMMA beads. Second stage: arthrodesis.ResultsThe goal of surgery was reached without complications in two out of four patients. An absence of bony bridging was noted in the fourth patient after 9 months. A revision adding cancellous bone grafts and resorting to an intramedullary fixation led to a success.