Stabilization of Juxta-Physeal Distal Tibial and Fibular Fractures in a Juvenile Tiger Using a Hybrid Circular-Linear External Fixator

OBJECTIVE: To report stabilization of closed, comminuted distal metaphyseal transverse fractures of the left tibia and fibula in a tiger using a hybrid circular-linear external skeletal fixator. STUDY DESIGN: Clinical report. ANIMAL: Juvenile tiger (15 months, 90 kg). METHODS: From imaging studies, the tiger had comminuted distal metaphyseal transverse fractures of the left tibia and fibula, with mild caudolateral displacement and moderate compression. Multiple fissures extended from the fractures through the distal metaphyses, extending toward, but not involving the distal tibial and fibular physes. A hybrid circular-linear external skeletal fixator was applied by closed reduction, to stabilize the fractures. RESULTS: The fractures healed and the fixator was removed 5 weeks after stabilization. Limb length and alignment were similar to the normal contralateral limb at hospital discharge, 8 weeks after surgery. Two weeks later, the tiger had fractures of the right tibia and fibula and was euthanatized. Necropsy confirmed pathologic fractures ascribed to copper deficiency. CONCLUSION: Closed application of the hybrid construct provided sufficient stability to allow this 90 kg tiger's juxta-articular fractures to heal with minimal complications and without disrupting growth from the adjacent physes.

Use of a painless external fixator for unilateral mandibular fracture repair in nine equids

OBJECTIVE: To report use of a pinless external fixator (PEF) for unilateral mandibular fractures in 9 equids. STUDY DESIGN: Case series. ANIMALS: Equids (n=9) with unilateral mandibular fractures. METHODS: All fractures were stabilized with the AO/ASIF PEF using a minimum of 4 clamps, under general anesthesia. Fracture configuration, complications, outcome, and owner satisfaction were evaluated. RESULTS: All fractures were stabilized; 2 equids were euthanatized; 1 because of an inability to stand after surgery and 1 because of owner decision after PEF dislodgement. Seven repairs healed with good outcome and owner satisfaction. Complications included dislodgement of the PEF (3), bone sequestration (3), and weight loss (1). Drainage associated with repair resolved after removal of sequestra and clamps. CONCLUSIONS: Stabilization of unilateral mandibular fractures with the PEF in horses was minimally invasive with minimal risk of tooth root interference; however, after care is time consuming. CLINICAL RELEVANCE: PEF is an alternative technique for stabilizing unilateral mandibular fractures in equids.

In vitro biomechanical testing of a micro external skeletal fixator

OBJECTIVE To biomechanically test the properties of three different Universal Micro External Fixator (UMEX™) configurations with regard to their use in very small animals (<5kg) and compare the UMEX system to the widely used IMEX External Skeletal Fixation (SK™) system in terms of stiffness, space needed for pin placement and weight. METHODS Three different UMEX configurations (type Ia, type Ib, and type II modified) and one SK configuration type Ia were used to stabilize Delrin plastic rods in a 1 cm fracture gap model. These constructs were tested in axial compression, craniocaudal bending, mediolateral bending, and torsion. Testing was conducted within the elastic range and mean stiffness in each mode was determined from the slope of the linear portion of the load-deformation curve. A Kruskal Wallis one-way analysis of variance on ranks test was utilized to assess differences between constructs (p <0.05). RESULTS The UMEX type II modified configuration was significantly stiffer than the other UMEX configurations and the SK type Ia, except in craniocaudal bending, where the SK type Ia configuration was stiffer than all UMEX constructs. The UMEX type Ia configuration was significantly the weakest of those frames. The UMEX constructs were lighter and smaller than the SK, thus facilitating closer pin placement. CONCLUSIONS Results supported previous reports concerning the superiority of more complex constructs regarding stiffness. The UMEX system appears to be a valid alternative for the treatment of long-bone fractures in very small animals.

Lateral external fixation: a new surgical technique for displaced unreducible supracondylar humeral fractures in children

BACKGROUND: Percutaneous Kirschner wire fixation represents the classic treatment for displaced supracondylar humeral fractures in childhood. This type of treatment first requires satisfactory reduction of the fracture. Failure to achieve a satisfactory reduction or inadequate stabilization can result in instability of the fracture fragments, which can result in either an unsatisfactory cosmetic or functional outcome. In our experience, these problems can be overcome with the use of a small lateral external fixator. METHODS: Between 1999 and 2005, thirty-one of 170 Gartland type-III supracondylar humeral fractures were treated with a lateral external fixator. The outcome of treatment was analyzed with regard to limb alignment, elbow movement, cosmetic appearance, and patient satisfaction. RESULTS: In twenty-eight of the thirty-one patients, a satisfactory reduction was achieved with closed methods. All children except one had a normal or good range of movement. The cosmetic result was excellent in all cases. All of the children and their parents stated that they would choose this treatment again. CONCLUSIONS: The use of a small lateral external fixator seems to be a safe alternative for the treatment of displaced supracondylar fractures of the humerus when a closed reduction appears to be unattainable by means of manipulation alone or when sufficient stability is not achieved with standard methods of Kirschner wire fixation.

Treatment of posttraumatic cubitus varus in children and adolescents. Supracondylar humeral osteotomy using radial external fixation

OBJECTIVE Precise adaptable fixation of a supracondylar humerus osteotomy with a radial/lateral external fixator to correct posttraumatic cubitus varus. INDICATIONS Acquired, posttraumatic cubitus varus as a result of a malhealed and unsatisfactorily treated supracondylar humerus fracture. Idiopathic, congenital cubitus varus (very seldom) if the child (independent of age and after complete healing) is cosmetically impaired; stability of the elbow is reduced due to malalignment (hyperextension); secondary problems and pain (e. g., irritation of the ulnar nerve) are expected or already exist; or there is an explicit wish of the child/parents (relative indication). CONTRAINDICATIONS In principle there are no contraindications provided that the indication criteria are filled. The common argument of age does not represent a contraindication in our opinion, since angular remodeling at the distal end of the humerus is practically nonexistent. SURGICAL TECHNIQUE Basically, the surgical technique of the radial external fixator is used as previously described for stabilization of complex supracondylar humeral fractures. With the patient in supine position, the arm is placed freely on an arm table. Using a 4-5 cm long skin incision along the radial, supracondylar, the extracapsular part of the distal humerus is prepared, whereby great caution regarding the radial nerve is advised. In contrast to the procedure used in radial external fixation for supracondylar humeral fracture treatment, two Schanz screws are always fixed in each fragment at a distance of 1.5-2 cm. The osteotomy must allow the fragment to freely move in all directions. The proximal and distal two Schanz screws are then connected with short 4 mm carbon or stainless steel rods. These two rods are connected with each other over another rod using the tub-to-tub technique. Now the preliminary correction according the clinical situation can be performed and the clamps are tightened. Anatomical axis and function are checked. If these are radiologically and clinically perfect, all clamps are definitively tightened; if the alignment or the function is not perfect, then further adjustments can be made. POSTOPERATIVE MANAGEMENT Due to the excellent stability, further immobilization not necessary. Immediate functional follow-up treatment performed according to pain. RESULTS Adequate healing is usually expected within 6 weeks. At this time the external fixator can be removed in the fracture clinic. Because the whole operation is performed in an extraarticular manner and the mobility of the elbow is not affected, deterioration of function has never been observed. Also regarding the cosmetic/anatomical situation, good results are expected because they were already achieved intraoperatively.

Minimal-invasive percutaneous reduction and transsacral screw fixation for U-shaped fractures

STUDY DESIGN Technical note and case series. OBJECTIVE To introduce an innovative minimal-invasive surgical procedure reducing surgery time and blood loss in management of U-shaped sacrum fractures. SUMMARY OF BACKGROUND Despite their seldom appearance, U-shaped fractures can cause severe neurological deficits and surgical management difficulties. According to the nature of the injury normally occurring in multi-injured patients after a fall from height, a jump, or road traffic accident, U-shaped fractures create a spinopelvic dissociation and hence are highly unstable. In the past, time-consuming open procedures like large posterior constructs or shortening osteotomies with or without decompression were the method of choice, sacrificing spinal mobility. Insufficient restoration of sacrococcygeal angle and pelvic incidence with conventional techniques may have adverse long-term effects in these patients. METHODS In a consecutive series of 3 patients, percutaneous reduction of the fracture with Schanz pins inserted in either the pedicles of L5 or the S1 body and the posterior superior iliac crest was achieved. The Schanz pins act as lever, allowing a good manipulation of the fracture. The reduction is secured by a temporary external fixator to permit optimal restoration of pelvic incidence and sacral kyphosis. Insertion of 2 transsacral screws allow fixation of the restored spinopelvic alignment. RESULTS Anatomic alignment of the sacrum was possible in each case. Surgery time ranged from 90 to 155 minutes and the blood loss was <50 mL in all 3 cases. Two patients had very good results in the long term regarding maintenance of pelvic incidence and sacrococcygeal angle. One patient with previous cauda equina decompression had loss of correction after 6 months. CONCLUSIONS Percutaneous reduction and transsacral screw fixation offers a less invasive method for treating U-shaped fractures. This can be advantageous in treatment of patients with multiple injuries.

Radialer externer Fixateur zur geschlossenen Behandlung problematischer suprakondylärer Humerusfrakturen Typ III und IV bei Kindern und Jugendlichen

Operationsziel Geschlossene, anatomische Reposition und sichere Fixation von problematischen suprakondylären Typ-III- und Typ-IV-Humerusfrakturen, die mit den herkömmlichen Operationsmethoden nur schwierig geschlossen zu behandeln sind. Indikationen Gemäß der AO-Kinderklassifikation der suprakondylären Humerusfrakturen vom Typ III und IV: Frakturen, welche nicht geschlossen mittels üblicher Repositionsmethoden reponierbar sind sowie Frakturen, die nicht mittels der üblichen, gekreuzten perkutanen Kirschner-Draht-Technik zu fixieren sind. Bei schweren Schwellungszuständen, offener Fraktur oder initial neurologischen und/oder vaskulären Problemen („pulseless pink hand“) sowie bei mehrfachverletzten Kindern, welche eine optimale Rehabilitation benötigen und die Extremität gipsfrei sein sollte. Bei Kindern mit Komorbiditäten (z. B. Anfälle, Spastizität), die eine bessere Stabilität benötigen. Kontraindikationen Prinzipiell keine Kontraindikationen Operationstechnik Im nichtreponierten Zustand unter Durchleuchtungskontrolle Einbringen einer einzelnen Schanz-Schraube in den lateralen (radialen) Aspekt des distalen Fragments, welches sich in der streng seitlichen Röntgenprojektion als „Sand-Uhr“- bzw. Kreisform des Capitulum humeri darstellt. Je nach Größe dieses distalen Fragments kann die Schanz-Schraube rein epiphysär oder metaphysär liegen. Danach in absolut streng seitlicher Projektion des distalen Humerus im Bereich des meta-diaphysären Übergangs Einbohren einer 2. Schanz-Schraube unabhängig von der Ersten, die möglichst rechtwinklig zur Längsachse des Humerus in der a.-p.-Ebene zu liegen kommen sollte, um spätere Manipulationen mittels „Joy-Stick“-Technik zu erleichtern. Sind die beiden Schanz-Schrauben mehr oder weniger in beiden Ebenen parallel, so ist die Fraktur praktisch anatomisch reponiert. Nach erreichter Reposition Feinjustierung aller Achskomponenten. Sicherung der Flexion/Extension mittels einem von radial, distal eingebrachten sog. Anti-Rotations-Kirschner-Drahts, der die Stabilität signifikant erhöht und eine Drehung des distalen Fragments um die einzelne Schanz-Schraube verhindert. Postoperative Behandlung Keine zusätzliche Gipsruhigstellung notwendig. Es sollte eine funktionelle Nachbehandlung erfolgen. Ergebnisse Gemäß unserer Langzeitstudien bewegen die meisten Kinder bereits zum Zeitpunkt der ambulanten Pin-Entfernung in der Frakturambulanz ihren Ellbogen weitgehend normal. Bei einer Follow-up-Zeit über 40 Monate hatten 30/31 Kindern eine seitengleiche Achse und Beweglichkeit.

Coronary collateral growth by external counterpulsation: a randomised controlled trial

The efficacy of external counterpulsation (ECP) on coronary collateral growth has not been investigated in a randomised controlled study. Objective To test the hypothesis that ECP augments collateral function during a 1 min coronary balloon occlusion.

How to assess the external validity of therapeutic trials: a conceptual approach

Background External validity of study results is an important issue from a clinical point of view. From a methodological point of view, however, the concept of external validity is more complex than it seems to be at first glance. Methods Methodological review to address the concept of external validity. Results External validity refers to the question whether results are generalizable to persons other than the population in the original study. The only formal way to establish the external validity would be to repeat the study for that specific target population. We propose a three-way approach for assessing the external validity for specified target populations. (i) The study population might not be representative for the eligibility criteria that were intended. It should be addressed whether the study population differs from the intended source population with respect to characteristics that influence outcome. (ii) The target population will, by definition, differ from the study population with respect to geographical, temporal and ethnical conditions. Pondering external validity means asking the question whether these differences may influence study results. (iii) It should be assessed whether the study's conclusions can be generalized to target populations that do not meet all the eligibility criteria. Conclusion Judging the external validity of study results cannot be done by applying given eligibility criteria to a single target population. Rather, it is a complex reflection in which prior knowledge, statistical considerations, biological plausibility and eligibility criteria all have place.

Restoration of mutant cytochrome P450 reductase activity by external flavin

Cytochrome P450 oxidoreductase (POR) supplies electrons from NADPH to steroid and drug metabolizing reactions catalyzed by the cytochrome P450s located in endoplasmic reticulum. Mutations in human POR cause a wide spectrum of disease ranging from disordered steroidogenesis to sexual differentiation. Previously we and others have shown that POR mutations can lead to reduced activities of steroidogenic P450s CYP17A1, CYP19A1 and CYP21A1. Here we are reporting that mutations in the FMN binding domain of POR may reduce CYP3A4 activity, potentially influencing drug and steroid metabolism; and the loss of CYP3A4 activity may be correlated to the reduction of cytochrome b(5) by POR. Computational molecular docking experiments with a FMN free structural model of POR revealed that an external FMN could be docked in close proximity to the FAD moiety and receive electrons donated by NADPH. Using FMN supplemented assays we have demonstrated restoration of the defective POR activity in vitro.

The use of weightbearing radiographs to assess the stability of supination-external rotation fractures of the ankle

Isolated lateral malleolar fractures usually result from a supination-external rotation (SER) injury and may include a deltoid ligament rupture. The necessity of operative treatment is based on the recognition of a relevant medial soft-tissue disruption. Currently used tests to assess ankle stability include manual stress radiographs and gravity stress radiographs, but seem to overestimate the need for fracture fixation.

Reversed shoulder arthroplasty with modified L'Episcopo for combined loss of active elevation and external rotation

In patients with a rotator cuff-deficient shoulder, a combined loss of active elevation and external rotation (CLEER) can occur when both the infraspinatus and teres minor muscles are absent. A reverse shoulder arthroplasty (RSA) can restore active elevation in these patients but cannot restore active external rotation because there are no other external rotator cuff muscles. We hypothesized that a modified L'Episcopo procedure (latissimus dorsi [LD] and teres major [TM] transfer) with a simultaneous RSA would restore shoulder function and activities of daily living (ADLs).