Frank Plasschaert

Endothelial Outgrowth Cells Are Not Derived From CD133 + Cells or CD45 + Hematopoietic Precursors

Objective—Two types of endothelial progenitor cells (EPCs), early EPCs and late EPCs (also called endothelial outgrowth cells [EOCs]), were described in vitro previously. In this report, we dissect the phenotype of the precursor(s) that generate these cell types with focus on the markers CD34, CD133, and vascular endothelial growth factor receptor-2 (VEGFR2) that have been used to identify putative circulating endothelial precursors. We also included CD45 in the analysis to assess the relation between CD34+ hematopoietic progenitors (HPC), CD34+ endothelial precursors, and both in vitro generated EPC types. Addressing this issue might lead to a better understanding of the lineage and phenotype of the precursor(s) that give rise to both cell types in vitro and may contribute to a consensus on their flowcytometric enumeration. Methods and Results—Using cell sorting of human cord blood (UCB) and bone marrow (BM) cells, we demonstrate that EOC generating precursors are confined to a small CD34+CD45− cell fraction, but not to the CD34+CD45+ HPC fraction, nor any other CD45+ subpopulation. CD34+CD45+ HPC generated monocytic cells that displayed characteristics typical for early EPCs. Phenotypic analysis showed that EOC generating CD34+CD45− cells express VEGFR2 but not CD133, whereas CD34+CD45+ HPC express CD133 as expected, but not VEGFR2. Conclusion—EOCs are not derived from CD133+ cells or CD45+ hematopoietic precursors.

Functional recovery after a reverse prosthesis for reconstruction of the proximal humerus in tumor surgery

An alternative treatment for primary bone tumors of the proximal humerus was assessed. Four patients, who made full functional recovery after complete resection of the proximal humerus inclusive of the rotator cuff and subsequent reconstruction with a reverse shoulder prosthesis, were examined clinically and radiographically. Distinct medialization of the center of rotation of the glenohumeral joint (28 mm) and elongation of the remaining deltoid muscle (116%) were measured. Increased scapular rotation (118%) was observed. The radiologic results and thoracoscapular rhythm analyses were implemented in a three-dimensional computerized model of the glenohumeral joint. This allowed us to calculate a doubling of the moment of the deltoid abductor muscle in the true scapular plane. After tumor surgery, in which the proximal humerus is resected without reinserting the rotator cuff, full functional recovery of the shoulder can be obtained with a total shoulder prosthesis, medializing the glenohumeral center of rotation and elongating the remaining deltoid muscle. Level of Evidence: Therapeutic study, Level IV (case series-no, or historical control group)

EOSINOPHILIC GRANULOMA. A DIFFERENT BEHAVIOUR IN CHILDREN THAN IN ADULTS

Localised Langerhans-cell histiocytosis of bone (eosinophilic granuloma) is a benign tumour-like condition with a variable clinical course. Different forms of treatment have been reported to give satisfactory results. However, previous series all contain patients with a wide age range. Our aim was to investigate the effect of skeletal maturity on the rate of recurrence of isolated eosinophilic granuloma of bone excluding those arising in the spine. We followed up 32 patients with an isolated eosinophilic granuloma for a mean of five years; 17 were skeletally immature. No recurrences were noted in the skeletally immature group even after biopsy alone. By contrast, four of 13 skeletally mature patients had a recurrence and required further surgery. This suggests that eosinophilic granuloma has a low rate of recurrence in skeletally immature patients.

Quantified measurement of subacromial impingement.

We modified the Hawkins impingement maneuver in order to develop a quantifiable and reproducible impingement test. The involved anatomic structures were examined with magnetic resonance imaging of 3 cadaveric shoulders. The reproducibility of the clinical sign was assessed with an interobserver and intraobserver reliability test, with calculation of the intraclass correlation coefficient (ICC). The quantified Hawkins maneuver appears to be a reproducible clinical test (median interobserver ICC, 0.9331; median intraobserver ICC, 0.9748) and creates bony contact between the greater tuberosity and the anterolateral acromion. This test enables the clinician to quantify the subacromial space.

A known technique for meniscal repair in common practice

In this retrospective study, we calculated the healing rate of meniscal repairs performed with an outside-in technique. We describe complications encountered and evaluate some known criteria used in the decision to perform a meniscal repair instead of partial meniscectomy. Included is a brief description of the surgical technique and of the trauma type and the meniscal lesions that were repaired. The technique has a high degree of success (74% of the meniscal repairs survived during a mean follow-up of 3.5 years). Although there is a 25% complication rate, no serious or permanent complications were added by repairing menisci instead of performing a partial meniscectomy. For this reason we think saving even a relatively low percentage of menisci may be worthwhile. We can also conclude that an anterior cruciate ligament-deficient knee that is stable can still have a good result in meniscal repair, without performing cruciate reconstruction. In each case, however, individual patient issues such as age, activity level, and associated lesions have to be considered.

Efectos de la variación muscular en la prueba neurodinámica del nervio mediano en una población sana con arco axilar de Langer

Objetivo La prueba neurodinamica del nervio mediano (PNES1, prueba neurodinamica 1 de la extremidad superior, o ULNT1 en ingles) se utiliza con frecuencia para evaluar la mecanica y la fisiologia del plexo braquial y del nervio mediano. El presente estudio investiga las PNES1 positivas en una poblacion sana con arco axilar de Langer (AAL) y analiza si el AAL afecta al arco de movimiento durante la extension de codo (AM-EC) durante la PNES1. Material y metodos De los 640 voluntarios examinados, finalmente se incluyeron 26 lados con AAL. La realizacion de un cuestionario clinico adicional revelo “sintomas menores” en algunos sujetos. Estos sintomas menores no se consideraron un trastorno porque no suponian un obstaculo para la realizacion de las actividades diarias y los sujetos no solicitaron atencion medica. Este estudio investiga si la PNES1 puede producir o reproducir sintomas menores o respuestas anormales en sujetos con AAL. Se comparo el AM-EC del lado izquierdo y derecho de los sujetos. Por otra parte, se comparo el angulo de sustraccion, que es el efecto de colocar la columna cervical en flexion lateral contralateral, entre los lados con AAL y los controles. Resultados Los lados con arco axilar de Langer mostraron un aumento significativo en la aparicion de sintomas menores y PNES1 positivas, pero no se observo efecto alguno en el AM-EC. Conclusiones Estos hallazgos indican que el AAL puede afectar de forma transitoria al haz neurovascular axilar. La falta de efectos sobre los AM-EC puede ser consecuencia del origen vascular de los sintomas menores o de una respuesta del nervio cubital/cordon medial a la PNES1.