Avascular osteonecrosis after hyperthermia in children and adolescents with pelvic malignancies: a retrospective analysis of potential risk factors.

PURPOSE: In children with locally advanced or recurrent malignant tumours, prognosis can be improved by regional deep hyperthermia (RHT) in combination with platin-based chemotherapy. However, because of the increasing number of patients that achieve long-time remission with this therapy, it is necessary to evaluate long-term sequelae of thermochemotherapy. During the years 1993-2004 one has observed avascular osteonecrosis (AON) of the femoral head after RHT in seven children with pelvic germ cell tumours or rhabdomyosarcomas. METHODS: Although AON may develop in patients with malignancies treated with chemo- or radiotherapy alone, RHT might nevertheless contribute to the occurrence of AON. In order to determine potential risk factors for AON after RHT, this study analysed the relationship of AON to the patient's age, medical history and treatment parameters such as thermal dose equivalent and power output. RESULTS AND CONCLUSIONS: In the present study AON was associated with young age as well as intensity of hyperthermia indicated by high power levels that exceed 20 W per kg body weight and/or application of eight or more heat sessions as well as additional radiotherapy. Based on this observation, it was assumed that an optimized three dimensional thermal field modelling may be helpful to avoid hazardous temperatures in the femoral heads during RHT treatment and to reduce AON of the femoral heads.     

Intravenous Iloprost: A New Therapeutic Option for Patients with Post-Transplant Distal Limb Syndrome (PTDLS)

The purpose of this study was to investigate the application of intravenous iloprost as a novel therapy for the treatment of post-transplant distal limb syndrome (PTDLS). PTDLS is a benign but disabling complication in the first year after renal transplantation. It is characterized by bilateral, often incapacitating pain in the feet and or knees on motion and a significant rise in alkaline phosphatase levels on laboratory evaluation. On MRI, bone marrow edema of the affected bone regions can be demonstrated. PTDLS differs from steroid induced osteonecrosis of the hip in terms of localization, an average cumulative steroid dosage within expected limits, and a benign outcome, as PTDLS does not progress to overt cell necrosis. From August 2003 to April 2005 we treated 10 patients with MRI-proven diagnosis of PTDLS following a standardized regimen of intravenous iloprost over 5 days. Iloprost led to prompt pain relief measured on a visual analogous scale (VAS) ranging from 1 to 10 (5.6 +/- 1.5 before vs. 2.1 +/- 1.3 after treatment, p = 0.0004). PTDLS represents a benign but disabling complication following renal transplantation. Intravenous iloprost might be a promising therapeutic concept leading to a quick relief of symptoms without relevant side effects.     

Proliferation and Osteogenic Differentiation of Mesenchymal Stem Cells Cultured onto Three Different Polymers <Emphasis Type="Italic">In Vitro</Emphasis>

In this study, the osteoinductive and cell-binding properties of three different resorbable polymers were evaluated by human mesenchymal stem cells (MSCs). MSCs were isolated, expanded, and cultivated onto resorbable D,D,L,L-polylactide (PLLA), collagen I/III, and polygalactin-910/polydioxanone (PGPD) scaffolds in vitro. To evaluate the influence of dexamethasone, ascorbic acid, and beta-glycerolphosphate (DAG) on osteoblast differentiation, MSCs were incubated in a DAG-enriched medium. After a 28-day period in vitro, the cellular loaded polymers were digested enzymatically by papain and HCl. The Ca(2+) content of the biomembranes was evaluated by an o-kresolphthalein-complexon reaction via photometer. A PicoGreen assay was performed for dsDNA quantification. Significant differences between the number of adherent MSCs were documented (collagen > PLLA > PGPD). Compared to the initial number of adherent cells, all biomaterials induced a significant decrease in cellular adherence after 28 days in vitro. The presence of DAG-enriched culture medium stimulated the cellular proliferation for PLLA and slightly for PGPD, whereas cell proliferation was inhibited when MSCs were cultivated onto collagen I/III. In comparison with the control groups, all biomaterials (PLLA, PGPD, and collagen I/III) showed a significant increase in local Ca(2+) accumulation under DAG stimulation after 28 days in vitro. Furthermore, collagen I/III and PLLA scaffolds showed osteoinductive properties without DAG stimulation. These results were verified by immunocytochemical stainings against osteoblast-typical markers (osteopontin and alkaline phosphatase) and completed by calcified matrix detection (von Kossa staining). MSCs were identified by CD105 and CD13 antigen expression. Corresponding to an absence of CD34, CD45, and collagen II expression, we found no chondrogenic or hematopoietic cell differentiation. The results indicate significant differences for the proliferation, differentiation, adherence, and Ca(2+) accumulation between the tested polymers in a MSC culture.     

Biometrical analysis of the shoulder joint regarding glenoid implant dimensions for arthroplasty

Purpose

Reduced bone stock and difficult intraoperative orientation are challenges in glenoid replacement surgery. New implant designs and methods for fixation, such as locking screws, extra-long central pegs and/or central compression screws are targeting these issues. The objective of this study is the analysis of the glenoid dimension regarding maximum central peg diameter and peg length (PL), and maximum screw length (SL) for glenoid fixation.

Methods

Retrospective analysis of magnetic resonance imaging (n = 50) scans. Measurement of the maximum inferior glenoid diameter (GD), SL, maximum length of a 9.9, 10 and 11.4 mm central peg (PL) in the transverse plane; glenoid version (GV), humeral head diameter (HHD). Two independent measurements.

Results

Mean age: 49.0 ± 15.7 years (17–80) (n = 20 female, 49.6 ± 16.0; n = 30 male, 48.6 ± 15.7). Mean values of measurement were GD: 28.9 ± 3.7 mm (21–39); SL: 34.1 ± 4.9 mm (26–44); PL 9.9 mm: 19.4 ± 4.3 mm (9–30); PL 10 mm: 19.0 ± 4.4 mm (8–30); PL 11.4 mm: 16.5 ± 4.1 mm (7–26) with significant gender differences (p = 0.001; p = 0.022; p = 0.001); GV: ?0.6° ± 4.9° (?10 to 11); HHD: 50.0 mm ± 4.9 (41–61). There was good correlation between PL and SL (r = 0.32, p = 0.024) and for GD and PL (r = 0.61, p = 0.001; r = 0.57, p = 0.001; r = 0.96, p = 0.001). The ratio of HHD and GD was very constant with 0.6 ± 0.07.

Conclusions

These data indicate the high interindividual variability of glenoid morphology including significant gender-related differences. The good correlation between humeral head size and GD and maximum central PL can be helpful for cases with reduced bone stock in decision-making about implant size and bone grafting.     

Symptomatic Femoroacetabular Impingement: Does the Offset Decrease Correlate With Cartilage Damage? A Pilot Study

Background

Current measures of the reduced head-neck offset such as residual deformity of slipped capital femoral epiphysis (SCFE) including the alpha angle, which measures the femoral head-neck sphericity but does not account for acetabular abnormalities, do not represent the true magnitude of the deformity and the mechanical consequences. The beta angle (angle between the femoral head-neck junction and acetabular rim) accounts for the morphology of both the acetabulum and femur and, thus, may be the more appropriate parameter for assessing SCFE deformity.

Questions/purposes

We determined (1) whether the beta angle could be reliably measured on MRI; and (2) whether the beta angle correlates with the cartilage status.

Methods

We recruited 10 adult patients (mean age, 28 years) with symptomatic cam femoroacetabular impingement and 15 asymptomatic volunteers (mean age, 24 years) to have three-dimensional MRI including delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) for cartilage status assessment. Corresponding alpha angles, beta angles, and acetabular dGEMRIC indices were obtained in seven radial reformats to assess the hip in seven regions (anterior to superior and posterior).

Results

We noted high reproducibility for both alpha and beta angle measurements. The dGEMRIC indices correlated with beta angles in the superoinferior and superior regions but not the alpha angles.

Conclusions

Beta angle measurement in radial MR images is reproducible and appears to correspond to cartilage damage in the superior regions of the hip. The beta angle may be a useful parameter to assess hip deformity in the followup of SCFE although further confirmation is warranted.     

Hormone

Ohne Zusammenfassung