Stefan Altermatt

Cross-linking of the dermo-epidermal junction of skin regenerating from keratinocyte autografts. Anchoring fibrils are a target for tissue transglutaminase

Since transglutaminases create covalent gamma-glutamyl-epsilon-lysine cross-links between extracellular matrix proteins they are prime candidates for stabilizing tissue during wound healing. Therefore, we studied the temporo-spatial expression of transglutaminase activity in skin regenerating from cultured epithelial autografts in severely burned children by the specific incorporation of monodansylcadaverine into cryostat sections from skin biopsies obtained between 5 d to 17 mo after grafting. The dansyl label was subsequently immunolocalized in the epidermis, dermal connective tissue, and along the basement membrane. Incubation of cryosections of normal and regenerating skin with purified tissue transglutaminase confirmed the dermo-epidermal junction and the papillary dermis as targets for this enzyme and revealed that in regenerating skin transamidation of the basement membrane zone was completed only 4-5 mo after grafting. Immunoelectron microscopy revealed that three distinct regions on the central portion of anchoring fibrils were positive for monodansylcadaverine in normal skin which were negative during the initial phase of de novo formation of anchoring fibrils in regenerating skin. Biochemically, we identified collagen VII as potential substrate for tissue transglutaminase. Thus, tissue transglutaminase appears to play an important role not only in cross-linking of the papillary dermis but also of the dermo-epidermal junction in particular.

Medial clavicular epiphysiolysis in children: the so-called sterno-clavicular dislocation

We retrospectively reviewed six pediatric cases of medial clavicular injury, i.e., epiphyseal separation (Salter/Harris type I or II injury), diagnosed between 1993 and 1997. The clavicular metaphysis was displaced posteriorly in three cases and anteriorly in three. On conventional radiographic views the diagnosis was initially missed in two of three retrosternal dislocations. A special X-ray projection (described by Heinig) or computed tomography (CT) permitted correct diagnosis. Anterior dislocations were immediately and correctly diagnosed. Closed reduction successfully treated retrosternal displacement in two of the three patients. The third patient needed open reduction and internal fixation. Open reduction and internal fixation had to be performed in all three patients with anterior displacement. Follow-up assessment showed perfect functional results in all cases. Direct visualization during open reduction, which was necessary in four of six cases, yielded clear evidence that the so-called sternoclavicular dislocation in children and young adults is, in fact, a fracture of the medial growth plate with posterior or anterior displacement of the metaphysis.

Efficacy of cultured epithelial autografts in pediatric burns and reconstructive surgery

BACKGROUND Cultured epithelial autografts are regularly used in burn patients, but they have not been tested in patients undergoing reconstructive surgery. The aim of this study was to analyze and compare the efficacy of cultured grafts in both burn and reconstructive surgery patients. METHODS In six children with severe and massive burns, full-thickness areas were grafted with cultured grafts. In another six children with hypertrophic or hyperpigmented scars, or both, cultured grafts were used to cover defects resulting from scar excision or deep dermabrasion. RESULTS In burn surgery the final cover rate averaged 60% (range, 0% to 100%). The functional and cosmetic results were good and at least equivalent to results after conventional grafting. Fragility, infection, and, in particular, mechanical instability of cultured grafts during the first weeks after transplantation were the main problems encountered. In reconstructive surgery the final cover rate was 100% in all patients. The functional and cosmetic results were very good and considered better than those obtained by using conventional grafting techniques. No major management problems were encountered. CONCLUSIONS In massively burned children, cultured epithelial autografts represent an effective additional and potentially lifesaving method to conventional grafting. Questions remain regarding the use of this technique to treat less severe burns. For resurfacing-type scar revisions, cultured epithelial autografts yield excellent results that appear to be superior to those of conventional techniques.

Fractures of the neck of the radius in children. Early experience with intramedullary pinning.

The treatment of fractures of the neck of the radius in children is difficult, particularly if the angulation of the fracture exceeds 60 degrees. Since 1994 we have used closed reduction and stabilisation with an intramedullary Kirschner wire in patients with grade-IV fractures according to the classification of Judet et al. In a retrospective analysis of a two-year period (1994 to 1996), 324 children with fractures of the elbow were treated in our department. Of these, 29 (9%) had a fracture of the neck of the radius; six were grade-IV injuries (1.9%). Five of the latter had an excellent postoperative result with normal movement of the elbow and forearm. One patient with a poor result had a concomitant dislocation of the elbow. Our results suggest that closed reduction and intramedullary pinning of grade-IV fractures allows adequate stabilisation while healing occurs.

Intrathecal baclofen therapy in children with severe spasticity: Outcome and complications

Abstract Objective: To investigate clinical efficacy and incidence of complications regarding intrathecal baclofen (ITB) therapy in children. Methods: Retrospective medical chart review of 15 paediatric patients with congenital brain injuries who underwent ITB implantation for treatment of severe spasticity between 2003 and 2009. Results: Compared to the preoperative state, ITB therapy significantly reduced spasticity of lower limbs with corresponding decrease of the modified Ashworth scale (p < 0.05), while baclofen dosage increased (p = 0.001). Cobb angle of patients with scoliosis prior to ITB therapy (n = 8) increased significantly (p < 0.05) during follow-up. Overall, 10 complications (nine device related and one accidental) were found in six patients (40%), mostly emerging within the first three years after implantation. Conclusion: Intrathecal baclofen is an effective therapy option for paediatric patients to significantly reduce spasticity of lower limbs. The high incidence of complications implicates the need for a close monitoring of the patients especially in the early post-operative period.

Intraventricular catheter placement by electromagnetic navigation safely applied in a paediatric major head injury patient

IntroductionIn the management of severe head injuries, the use of intraventricular catheters for intracranial pressure (ICP) monitoring and the option of cerebrospinal fluid drainage is gold standard. In children and adolescents, the insertion of a cannula in a compressed ventricle in case of elevated intracranial pressure is difficult; therefore, a pressure sensor is placed more often intraparenchymal as an alternative option.DiscussionIn cases of persistent elevated ICP despite maximal brain pressure management, the use of an intraventricular monitoring device with the possibility of cerebrospinal fluid drainage is favourable. We present the method of intracranial catheter placement by means of an electromagnetic navigation technique.

Hydroxyapatite ceramic implants for cranioplasty in children: a single-center experience

PurposeThe use of hydroxyapatite ceramic (HAC) implants for the treatment of skull defects in pediatric patients started 2010 at our institution. Ceramic implants facilitate osteoblast migration and therefore optimize osteointegration with the host bone. The purpose of this study is to report a single-center experience with this treatment modality.MethodsA retrospective review of all patients from July 2010 through June 2014 undergoing a cranioplasty using hydroxyapatite ceramic implant and managed at a single institution was performed. Indication for cranioplasty, the hospital course, and follow-up were reviewed. Bone density was measured in Hounsfield Units (HU) and osteointegration was calculated using Mimics Software® (Mimics Innovation Suite v17.0 Medical, Materialize, Leuven, Belgium).ResultsOver the 4-year period, six patients met criteria for the study. Five patients had an osteointegration of nearly 100%. One patient had an incomplete osteointegration with a total bone-implant contact area of 69%. The mean bone density was 2800 HU (2300–3000 HU). Bone density alone is estimated to have a Hounsfield value between 400 and 2000 HU depending on the body region and bone quality. There were no major complications, and the patients were highly satisfied with the esthetical result.ConclusionHydroxyapatite ceramic implants for cranioplasty in pediatric patients are a good choice for different indications. The implants show excellent osteointegration and esthetical results.

Diagnostic performance of S100B protein serum measurement in detecting intracranial injury in children with mild head trauma

Objective To assess the accuracy of S100B serum level to detect intracranial injury in children with mild traumatic brain injury. Methods A multicenter prospective cohort study was carried out in the paediatric emergency departments of three tertiary hospitals in Switzerland between January 2009 and December 2011. Participants included children aged <16 years with a mild traumatic brain injury (GCS ≥13) for whom a head CT was requested by the attending physician. Venous blood was obtained within 6 h of the trauma in all children for S100B measurement before a head CT was performed. As the S100B value was not available during the acute care period, the patients management was not altered. The main measures were protein S100B value and the CT result. Results 20/73 (27.4%) included children had an intracranial injury detected on CT. S100B receiver operating characteristics area under the curve was 0.73 (95% CI 0.60 to 0.86). With a 0.14 µg/L cut-off point, S100B reached an excellent sensitivity of 95% (95% CI 77% to 100%) and 100% (95% CI 81% to 100%) in all children and in children aged >2 years, respectively. The specificity, however, was 34% (95% CI 27% to 36%) and 37% (95% CI 30% to 37%), respectively. Conclusions S100B has an excellent sensitivity but poor specificity. It is therefore an accurate tool to help rule out an intracranial injury but cannot be used as the sole marker owing to its specificity. Used with clinical decision rules, S100B may help to reduce the number of unnecessary CT scans.

Treating Displaced Distal Forearm Fractures in Children

Purpose:Distal forearm fractures are among the most common fractures in children. In the past few years the option of percutaneous pinning has gained more attention in the treatment of unstable fractures. However, it remains unclear in which cases a fracture or its reduction should be considered unstable.Study Design:In order to evaluate which type of fractures profit most from additional pinning after closed reduction, we performed a retrospective analysis of 225 consecutive cases using the recently published AO pediatric classification of long bone fractures.Results:After closed reduction, position in the cast was lost in 23% of the cases. The proportion of unstable reductions was much higher in completely displaced fractures. The amount of dislocation was more important than the type of fracture according to the AO classification proposal.Conclusions:Fully displaced fractures should always be reduced in a setting with pins immediately available. If anatomical reduction cannot be achieved, pinning is advocated. The AO proposal for pediatric long bone fracture classification could be a useful tool to render the diverse studies more comparable. However, the important feature of complete versus subtotal displacement is lacking.

Fractures of the neck of the radius in children

The treatment of fractures of the neck of the radius in children is difficult, particularly if the angulation of the fracture exceeds 60°. Since 1994 we have used closed reduction and stabilisation with an intramedullary Kirschner wire in patients with grade-IV fractures according to the classification of Judet et al. In a retrospective analysis of a two-year period (1994 to 1996), 324 children with fractures of the elbow were treated in our department. Of these, 29 (9%) had a fracture of the neck of the radius; six were grade-IV injuries (1.9%). Five of the latter had an excellent postoperative result with normal movement of the elbow and forearm. One patient with a poor result had a concomitant dislocation of the elbow.Our results suggest that closed reduction and intramedullary pinning of grade-IV fractures allows adequate stabilisation while healing occurs.