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Dive into the research topics where Hans Zwipp is active.

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Featured researches published by Hans Zwipp.


Clinical Orthopaedics and Related Research | 1993

Osteosynthesis of displaced intraarticular fractures of the calcaneus. Results in 123 cases.

Hans Zwipp; Harald Tscherne; Hajo Thermann; Theresa Weber

The operative treatment of intraarticular calcaneal fractures has three principal aims: restoration of height, length, and width of the calcaneus, reconstruction of the subtalar and calcaneocuboid joint surfaces, and stable osteosynthesis using an H-plate or screws. In 68% of the cases, the sustentacular fragment was the key to open reduction, making the medial approach mandatory. In complex fractures, a lateral approach is added. In “blow-out” fractures or cases with comminution of the sustentacular fragment, an extended lateral approach only is used. For precise preoperative planning of roentgenograms in three planes, four Brodens views and axial plus coroneal or three-dimensional computed tomography scans are required. From July 1983 to July 1990, 157 intraarticular calcaneal fractures were treated by open reduction. The results in 123 cases are 61% good or excellent, 32.5% satisfactory, and 6.5% poor. The following early complications occurred: superficial wound edge necrosis (8.3%), hematoma (2.5%), nonunion (1.3%), and infection (1.9%). Four patients (3.3%) in the follow-up group have developed degenerative changes severe enough to require subtalar fusion. To facilitate the comparison of results, new fracture classification and follow-up scoring systems have been devised.


Journal of Trauma-injury Infection and Critical Care | 2004

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

Achim Biewener; Ulf Aschenbrenner; Stefan Rammelt; R. Grass; Hans Zwipp

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.


Injury-international Journal of The Care of The Injured | 2009

Talar neck and body fractures

Stefan Rammelt; Hans Zwipp

Fractures of the talar neck and body are rare and serious injuries. The vast majority are either intra-articular or lead indirectly to an intra-articular incongruity through a dislocation at the talar neck. Because of the high energy needed to produce talar fractures, they are frequently seen in multiply injured and polytraumatised patients. Open fractures and fracture-dislocations are treated as emergencies. Preoperative planning of definite internal fixation requires CT scanning. To obtain a complete intra-operative overview allowing for anatomical reconstruction of the articular surfaces and the axial deviation bilateral approaches are usually necessary. Internal fixation is achieved with screws or mini-plates supplemented by temporary K-wire transfixation in cases of marked additional ligamentous instability. The clinical outcome after talar neck and body fractures is determined by the severity of the injury and the quality of reduction and internal fixation. The timing of definite internal fixation does not appear to affect the final result. The rates of avascular necrosis (AVN) correlate with the degree of initial dislocation. Only total AVN with collapse of the talar body leads to inferior results with the need for further surgery whilst prolonged immobilisation or offloading of the affected foot is not indicated for partial AVN. Talar malunions and non-unions after inadequate treatment of displaced fractures are debiliating conditions that should be treated by surgical correction. Treatment options include corrective osteotomy by recreating the former fracture with secondary fixation, free or vascularised bone grafting and salvage by realignment and fusion of the affected joint(s).


Foot & Ankle International | 2003

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

R. Grass; Stefan Rammelt; Achim Biewener; Hans Zwipp

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.


Foot & Ankle International | 2002

The value of subtalar arthroscopy in the management of intra-articular calcaneus fractures.

Stefan Rammelt; Johann Marian Gavlik; Sven Barthel; Hans Zwipp

A wealth of clinical and experimental data suggests, that anatomical restoration of the posterior calcaneal facet is a major predictor of outcome after intra-articular calcaneus fractures. The value of subtalar arthroscopy was examined in three clinical study groups (I–III). Materials and Methods: (I) The subtalar joint was inspected arthroscopically in 28 patients during hardware removal one year after open reduction and internal fixation (ORIF). This procedure was accompanied by subtalar arthrolysis in all cases. (II) Open subtalar arthroscopy was performed to evaluate the quality of reduction after ORIF of intra-articular calcaneus fractures in 59 cases. Arthroscopy was performed after seemingly exact reconstruction of the posterior facet as judged visually and fluoroscopically. (III) Arthroscopically assisted percutaneous reduction and screw fixation (PRSF) was performed in 18 patients with Sanders II fractures. Reduction was achieved with a Schanz screw introduced percutaneously into the tuberosity fragment and controlled fluoroscopically, while fine corrections were made under arthroscopic guidance. Results: (I) Clinical results after ORIF of intra-articular calcaneus fractures were highly correlated to the degree of residual incongruities and chondromalacia of the posterior facet as seen arthroscopically during hardware removal (P<0.01). (II) In 13 of 59 cases (22.0%) during ORIF despite seemingly accurate reduction, steps between 1–2 mm were detected arthroscopically in the posterior calcaneal facet and reduction was repeated subsequently in these cases. (III) Fifteen patients who underwent arthroscopically guided PRSF were re-evaluated after a minimum of one year with excellent clinical results (94.1 pts. with the AOFAS scales). No wound complications were seen. Conclusions: Subtalar arthroscopy provides a most precise and thorough view of the posterior facet of the calcaneus both in assessing the quality of initial reduction as well as evaluation during hardware removal after intra-articular calcaneus fractures. It is more precise than intra-operative fluoroscopy and less time consuming than standard Brodén views during surgery. The use of arthroscopy allows anatomical percutaneous reduction and screw fixation of Sanders II fractures. It therefore provides a useful additional tool in treating intra-articular calcaneus fractures.


Unfallchirurg | 2000

Verletzungen der unteren tibiofibularen Syndesmose

R. Grass; K. Herzmann; Achim Biewener; Hans Zwipp

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


Journal of Orthopaedic Trauma | 1998

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

Keita Ito; R. Grass; Hans Zwipp

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.


Unfallchirurg | 2010

Die Abbreviated Injury Scale (AIS)

C. Haasper; M. Junge; A. Ernstberger; H. Brehme; L. Hannawald; C. Langer; J. Nehmzow; Dietmar Otte; U. Sander; C. Krettek; Hans Zwipp

The new AIS (Abbreviated Injury Scale) was released with an update by the AAAM (Association for the Advancement of Automotive Medicine) in 2008. It is a universal scoring system in the field of trauma applicable in clinic and research. In engineering it is used as a classification system for vehicle safety. The AIS can therefore be considered as an international, interdisciplinary and universal code of injury severity. This review focuses on a historical overview, potential applications and new coding options in the current version and also outlines the associated problems.ZusammenfassungDie AIS (Abbreviated Injury Scale) ist von der AAAM (Association for the Advancement of Automotive Medicine) 2008 mit einem Update herausgegeben worden. Sie ist eines der universellen Scoringwerkzeuge im unfallchirurgischen Fachgebiet mit Einsatzpotenzial in Klinik und Forschung. Die Ingenieurswissenschaften nutzen sie in der Fahrzeugtechnik zur Bewertung der Fahrzeugsicherheit. Damit kann die AIS als internationale, interdisziplinäre und universelle Klassifikation der Verletzungsschwere angesehen werden. Dieser Beitrag liefert einen Überblick zur Historie, Anwendungsmöglichkeit und verbesserten Kodiermöglichkeiten durch die neu erschienene Version. Dabei werden aber auch Probleme aufgezeigt.AbstractThe new AIS (Abbreviated Injury Scale) was released with an update by the AAAM (Association for the Advancement of Automotive Medicine) in 2008. It is a universal scoring system in the field of trauma applicable in clinic and research. In engineering it is used as a classification system for vehicle safety. The AIS can therefore be considered as an international, interdisciplinary and universal code of injury severity. This review focuses on a historical overview, potential applications and new coding options in the current version and also outlines the associated problems.


Injury-international Journal of The Care of The Injured | 2002

The use of subtalar arthroscopy in open reduction and internal fixation of intra-articular calcaneal fractures

Johann Marian Gavlik; Stefan Rammelt; Hans Zwipp

Congruency of the subtalar joint is a major predictor of outcome after intra-articular calcaneal fractures. Because of the irregular shape of the posterior joint facet, minor steps may be overlooked with direct vision or intra-operative fluoroscopy during open reduction and internal fixation (ORIF). In a preliminary series of 15 subtalar arthroscopies during hardware removal after ORIF of intra-articular calcaneal fractures, patients with visible steps of 1 mm or more had significantly inferior functional results compared to those with an intact subtalar joint (117 vs. 158 points with the 200-point score, 71.3 vs. 91.2 points with the Maryland Foot Score, P<0.01). Congruency of the posterior facet was controlled arthroscopically in 47 intra-articular calcaneus fractures after open reduction and temporary K-wire-fixation. In 12 cases (25.5%), despite seemingly correct reduction as judged fluoroscopically, incongruencies in the posterior calcaneal facet were detected and reduction was repeated, temporarily removing the K-wires. After anatomical reduction a standard AO calcaneal plate was fixed to the lateral wall. Intra-operative arthroscopy appears to be useful in detecting minor incongruencies after ORIF of intra-articular calcaneus fractures. In the hands of an experienced surgeon it is less time demanding than intra-operative X-rays and more precise than fluoroscopy.


Journal of Orthopaedic Research | 2009

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

Wolfgang Schneiders; Antje Reinstorf; Achim Biewener; Alexandre Serra; R. Grass; Michael Kinscher; Jan Heineck; S. Rehberg; Hans Zwipp; Stefan Rammelt

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.

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Stefan Rammelt

Dresden University of Technology

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R. Grass

Dresden University of Technology

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S. Rammelt

Dresden University of Technology

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Achim Biewener

Dresden University of Technology

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M. Amlang

Dresden University of Technology

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Wolfgang Schneiders

Dresden University of Technology

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J. Heineck

Dresden University of Technology

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Sven Barthel

Dresden University of Technology

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M. Holch

Dresden University of Technology

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