Effects of Propofol on Cellular Bioenergetics in Human Skeletal Muscle Cells.

OBJECTIVES: Propofol may adversely affect the function of mitochondria and the clinical features of propofol infusion syndrome suggest that this may be linked to propofol-related bioenergetic failure. We aimed to assess the effect of therapeutic propofol concentrations on energy metabolism in human skeletal muscle cells. DESIGN: In vitro study on human skeletal muscle cells. SETTINGS: University research laboratories. SUBJECTS: Patients undergoing hip surgery and healthy volunteers. INTERVENTIONS: Vastus lateralis biopsies were processed to obtain cultured myotubes, which were exposed to a range of 1-10 µg/mL propofol for 96 hours. MEASUREMENTS AND MAIN RESULTS: Extracellular flux analysis was used to measure global mitochondrial functional indices, glycolysis, fatty acid oxidation, and the functional capacities of individual complexes of electron transfer chain. In addition, we used [1-C]palmitate to measure fatty acid oxidation and spectrophotometry to assess activities of individual electron transfer chain complexes II-IV. Although cell survival and basal oxygen consumption rate were only affected by 10 µg/mL of propofol, concentrations as low as 1 µg/mL reduced spare electron transfer chain capacity. Uncoupling effects of propofol were mild, and not dependent on concentration. There was no inhibition of any respiratory complexes with low dose propofol, but we found a profound inhibition of fatty acid oxidation. Addition of extra fatty acids into the media counteracted the propofol effects on electron transfer chain, suggesting inhibition of fatty acid oxidation as the causative mechanism of reduced spare electron transfer chain capacity. Whether these metabolic in vitro changes are observable in other organs and at the whole-body level remains to be investigated. CONCLUSIONS: Concentrations of propofol seen in plasma of sedated patients in ICU cause a significant inhibition of fatty acid oxidation in human skeletal muscle cells and reduce spare capacity of electron transfer chain in mitochondria.

Fractures of the scapular neck: diagnosis, classifications and treatment.

PURPOSE: Fractures of the scapular, or glenoid, neck are strongly debated in the relevant literature. Analysis of the respective studies, however, revealed a considerable confusion in terms of definition, terminology and diagnosis. In addition, there are few studies, primarily case reviews, dealing in detail with these fractures. The aim of this article is to present detailed information about fractures of the scapular neck, based on the analysis of our own experience and of the published literature. MATERIAL AND METHODS: Our group of 17 fractures of the scapular neck comprised 14 men and three women, with a mean age of 38 years (range, 24-55). The authors diagnosed four fractures of the anatomical neck, nine fractures of the surgical neck and five trans-spinous fractures of the neck. Of these 17 scapular neck fractures, six fractures were treated non-operatively, and 11 fractures were operated on via the posterior Judet approach. The mean follow-up was 4.9 years (range, 1-11). RESULTS: Fractures in all six non-operatively treated patients healed without complications in the anatomical position and with full function of the shoulder. In 11 operatively treated patients, all fractures of the scapula and clavicle healed within three months. In nine cases the function of the shoulder was subjectively and objectively assessed as normal, and in the remaining two cases as fair. CONCLUSION: The term "scapular, or glenoid, neck" covers three different types of fractures, i.e., fracture of the anatomical neck, fracture of the surgical neck and trans-spinous neck fracture. Fractures of the surgical neck are divided into stable, fractures with rotational instability and fully unstable fractures, depending on the integrity of the coracocacromial and coracoclavicular ligaments. Accurate diagnosis of fractures of the scapular neck requires 3D CT reconstructions. Undisplaced or minimally displaced fractures may be treated non-operatively, markedly displaced fractures constitute an indication for osteosynthesis via the Judet approach.

Fractures of the anatomical neck of the scapula: two cases and review of the literature.

Anatomical neck fractures of the scapula are rare. The authors have found in the literature only four radiologically documented fractures of the anatomical neck of the scapula. Two of them were published by Hardegger et al., the third case was published by Arts and Louette. The last case, in fact only a radiograph and a rather poor 3D CT reconstruction of a fracture of the anatomical neck of scapula, was published by Jeong and Zuckerman. Together with author's two patients, the group of radiologically verified anatomical neck fractures of the scapula comprises six cases in total (four men, one woman, one gender unspecified). Analysis of the radiographs showed that in all these cases, the fracture line separated only the glenoid fossa from the scapular body, with a short spike of the lateral border of the scapula. The proximal part of the vertical fracture line ran into the coracoglenoid notch, between the upper border of the glenoid and the base of the coracoid process. The distal part of the fracture line crossed the lateral border of the scapular body 2-4 cm distal to the inferior pole of the glenoid fossa. The gleniod fragment was always formed by the glenoid fossa and a short spike of the lateral border of the scapular body. In five cases, the glenoid fragment, together with the humeral head, was displaced distally and the humeral head came to lie below the level of the coracoid process. At the same time, the glenoid fragment rotated into a valgus position. Only in one case, did the radiographs fail to show valgus displacement and the fracture was angulated in the transverse plane. In all six cases, the subacromial space between the acromion and the humeral head was widened. All fractures were operated on via a Judet posterior approach. In five cases, the outcome of the operation was assessed at 3, 5, 12, 21 and 120 months after surgery, three-being rated as excellent or very good, one as good and one as poor.

Scapular body fractures: results of operative treatment.

The authors operated on 22 patients with scapular body fractures, with a mean age of 35 years. The minimal follow-up was 12 months. All patients were treated from the Judet posterior approach. The study included 14 cases of an isolated body fracture, three of scapular body fracture combined with fracture of the scapular neck and five of glenoid fossa fracture. In all 14 cases where a 3D computed tomography (CT) reconstruction was performed prior to operation, intraoperative findings corresponded to this reconstruction. In eight cases without preoperative 3D CT reconstruction, the correct type of fracture was identified in only two cases. We also identified three basic types of fractures of the lateral border of the scapula. The anatomical relationship between the glenoid fossa and scapular body, congruency and stability of the shoulder joint was achieved in all cases. The average constant score was 94.

Avascular necrosis of the femoral head in pertrochanteric fractures: a report of 8 cases and a review of the literature.

OBJECTIVE: To evaluate patients with pertrochanteric fractures (Type 31A1 + 2 ASIF/OTA classification) treated surgically and who subsequently developed avascular necrosis of the femoral head (ANFH). SETTING: University hospital. DESIGN: Retrospective clinical study and analysis of the literature. PATIENTS: From 1995 to 2003 the authors operated on 1,373 patients with pertrochanteric fractures. Eight patients with a mean age of 69 years (range, 52-78 years) subsequently developed ANFH. INTERVENTION: Five patients were treated with a dynamic hip screw (DHS), and 3 were treated with an intramedullary hip nail (IMHN). RESULTS: All fractures in these 8 patients healed without complications in 3 to 4 months. Avascular necrosis of the femoral head developed 4 months to 4 years after the operation. Detailed analysis of these cases did not reveal any risk factors or errors in surgical technique to account for the ANFH. Results of a literature review of 41 cases in addition to our 8 cases give us reason to believe the etiology of postoperative AFNH following surgical treatment of pertrochanteric fractures is probable injury to the deep branch of the medial circumflex artery at time of fracture. Other possible risk factors include high-energy trauma, comminution, displacement of the fragments, and atypical fracture line. CONCLUSIONS: ANFH develops in approximately 0.5-1% of all pertrochanteric fractures, mostly within 4 years after the injury and predominantly in patients older than 50 years of age. The diagnosis should be considered in patients who have undergone an operation previously and have symptoms that are unclear. Prevention of ANFH in these fractures includes an early reduction, stable fixation, and correct surgical technique.

Bosworth-type fibular entrapment injuries of the ankle: the Bosworth lesion. A report of 6 cases and literature review.

OBJECTIVES: To evaluate patients with Bosworth-type fibular entrapment injuries of the ankle. DESIGN: Retrospective clinical study and analysis of the literature. SETTING: University hospital. PATIENTS: Six cases treated for Bosworth-type fibular entrapment injuries (the Bosworth lesion) in the period 2001 to 2004. INTERVENTION: Five patients were treated with open reduction and internal fixation (ORIF), and 1 patient was treated with closed reduction and cast. RESULTS: All patients treated by ORIF healed without complications with a good subjective outcome. In 1 case treated nonoperatively, an ankle fusion had to be performed 2 years after injury for severe osteoarthritis. Additionally, we have recorded 3 cases, 2 not previously described in the literature, in which the fracture of the fibula was located at the middle or proximal third of its shaft.In the literature we found another 54 cases with dislocation of the fibula behind the posterior tubercle of the distal tibia. The analysis showed that morphology of the Bosworth lesion, as we prefer to refer to this complex fracture-dislocation, changes with age and may be divided into 3 basic types. In children and adolescents the dislocation of the distal fibula is associated with epiphyseolysis of the distal tibia; in young adults the fibula dislocates without fracture; in middle-aged and older adults, the dislocated fibula fractures, probably because of the decreased elasticity. CONCLUSIONS: The Bosworth lesion is a severe injury of the ankle, and its successful treatment requires a correct diagnosis based on careful initial clinical and radiographic evaluation and early surgical treatment.

Displaced fractures of the medial end of the clavicle: report of five cases.

The authors present a group of five men who sustained a displaced fracture of the medial end of the clavicle. In all cases, the diagnosis was confirmed by computed tomographic scan. Three young men with extra-articular fractures were treated operatively with a very good result. Two older men were treated nonoperatively, one with a good result (intra-articular fracture) and one with a fair result (extra-articular fracture). The method of treatment of fractures of the medial end of the clavicle depends primarily on the type and displacement of the fracture. Treatment decisions should be always based on a computed tomographic scan, because plain radiographs do not adequately image the medial clavicle. Surgical treatment of these fractures should be considered, particularly in young or physically active individuals.

Intraoperative reduction of the scapular body--a technical trick.

When internal fixation of the scapular neck and body fractures is performed, a problem may occur with reduction and retention of position of the lateral border of the scapula during surgery. For this purpose, the authors have developed their own technique of stabilization using a K-wire in a novel way. The technique is indicated in a 2-part shear unstable fracture of the lateral border. It cannot be used in fractures with an intercalated segment. A 2.5-mm drill bit is used to drill a 1.5-cm deep hole into the "medullary cavity" of each of the 2 fragments of the lateral border. A K-wire, 1.5 mm in diameter and 2.5-cm long, is inserted into the distal fragment. The protruding end of the K-wire is inserted into the hole in the proximal fragment. This intramedullary peg helps to maintain reduction and keeps both fragments stable. Subsequently, the lateral border is stabilized with a 3.5-mm reconstruction plate. This technique is quite simple and allows for a temporary stabilization of fragments without compromising the subsequent fixation by plate screws.