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.     

Aktuelle Behandlungsstrategie des Morbus Perthes

The long-term prognosis of Legg-Calvé-Perthes disease primarily depends on the spherical form of the femoral head and the congruency of the hip joint after healing. Of the many factors influencing the outcome only the range of mobility and containment can be addressed therapeutically. The mobility of the joint is maintained or restored through various conservative measures thus reducing joint deforming forces. If loss of containment becomes evident operative treatment is indicated, preferably in the early fragmentation stage. For biomechanical reasons correction of the acetabulum is preferred. For children less than 8.5 years old greater trochanteric apophyseodesis is warranted to prevent trochanteric overgrowth. The results of containment ameliorating surgery are promising. In older children with severe Legg-Calvé-Perthes disease the results are less promising.     

Preoperative halo-traction in severe paralytic scoliosis

AIM: During the past decades the treatment of severe paralytic scoliosis has developed towards surgical treatment. However there is controversial discussion about the need of pre-operative Halo-traction. The aim of this study was to built two groups of patients -- one group with and another one without pre-operative Halo-traction -- and to compare the results after surgical correction of scoliotic deformity with data from literature. METHOD: Between 2000-2003 twenty-five patients with severe neuromuscular spine deformity were treated surgically. Eight patients had preoperative Halo-traction, seventeen patients underwent directly operative correction and instrumentation. The evaluation included the pre- and postoperative X-rays as well those after Halo-traction before surgery. RESULTS: In the group without Halo-traction the scoliotic angle according to Cobb was reduced from 77 degrees to 33 degrees on average (mean correction of 44 degrees [57 %]). In the group with Halo-traction scoliosis was reduced from 85 degrees to 33 degrees on average (mean correction of 52 degrees [61 %]). CONCLUSION: The preoperative Halo-traction in patients with severe neuromuscular scoliosis indeed leads to radiologically higher correction, but this is not significant (p = 0.19) and only in single cases clinically relevant. In our point of view except from specific indications Halo-traction should not be applied in general as a standard procedure.     

Transmission of impulses from pre- to postganglionic vasoconstrictor and sudomotor neurons

Transmission of impulses of pre- to postganglionic neurons supplying skeletal muscle and skin of the cat's hindlimb and tail was investigated. The objective of the study was to determine whether these postganglionic neurons can be influenced from the preganglionic side by non-nicotinic synaptic mechanisms in the lumbar sympathetic chain ganglia. The activity of the postganglionic neurons was recorded from their axons being isolated from peripheral skin and muscle nerves. (1) Vasoconstrictor neurons can be activated by muscarinic action of released acetylcholine and by a non-cholinergic synaptic mechanism. This type of non-nicotinic excitation of postganglionic vasoconstrictor neurons requires the activation of thin, probably unmyelinated preganglionic axons and considerable summation. Postganglionic sudomotor and pilomotor neurons cannot be activated in this way. (2) Ongoing activity in postganglionic vasoconstrictor neurons, but not in sudomotor neurons, can be enhanced for up to 60 min by brief trains of stimuli applied to the preganglionic site. Also this enhancement requires the activation of thin preganglionic axons. (3) Stimulation of thin preganglionic axons leads to an activation of muscle vasoconstrictor neurons via non-nicotinic synaptic mechanisms in the ganglia after complete block of nicotine transmission. (4) Postganglionic vasoconstrictor neurons and sudomotor neurons may be inhibited by a catecholaminergic autogenic mechanism in the ganglia. (5) The results indicate that integration may take place in the sympathetic chain ganglia by other than divergent and convergent processes. In this integration muscarinic actions of released acetylcholine and non-cholinergic synaptic mechanisms may be involved.