[Comparison of Modifications of Femoral and Tibial Lengthening in Children]. / Srovnání modifikací prolongace femuru a bérce u detí.

PURPOSE OF THE STUDY Limb lengthening has always belonged to the most complex surgical techniques in paediatric orthopaedics. In our study, we compared the results of femoral and tibial lengthening using three different surgical techniques. The presented study aimed to shorten the duration of external fixation to a minimum and to reduce the complication rate. MATERIAL AND METHODS The retrospective study compared 74 patients (38 boys, 36 girls) who had undergone stepwise progressive lengthening of the femur or tibia between the years 2007 and 2019. The most frequent indication was the proximal focal femoral deficiency (PFFD, 33 patients). The total number of lengthening procedures was 130 (femur 72, tibia 58), the follow-up period was 2-14 years. The following modifications of surgical techniques were used: (i) standard approach, i.e. corticotomy with a two-stage removal of the fixator, (ii) preventive fixation with elastic stable intramedullary nails (ESIN) and also with a two-stage removal of the fixator, and (iii) standard approach with an early removal of the external fixator and plate osteosynthesis. RESULTS The mean lengthening achieved was 56 ± 18 (27-114) mm in femur and 54 ± 16 (25-110) mm in tibia. There was no statistical difference in the lengthening achieved by different modifications. The mean duration of external fixation in femur and tibia lengthening was comparable (166 and 164 days). The complications were observed in 60% of lengthening procedures, the most frequent being the pin release or axial malalignment of the lengthening (33 cases, 25%). The patients with ESIN displayed statistically the lowest complication rate (26%), the highest complication rate was seen in children with osteosynthesis using a plate (80%). CONCLUSIONS It follows from our results that fixation with intramedullary nails in comparison with the standard approach and plate osteosynthesis helped decrease the number of complications by more than 50%. The plate osteosynthesis is indicated in patients with repeated lengthening (achondroplasia, hypochondroplasia or PFFD with pronounced shortening) since it significantly reduces the duration of external fixation. Key words: limb lengthening, femur, tibia, surgical techniques, complications.

[Correction of Valgus Knee Deformity by Hemiepiphyseodesis: a Restrospective Analysis]. / Korekce valgózní deformity kolena u detí pomocí hemiepifyzeodézy: retrospektivní analýza.

PURPOSE OF THE STUDY Hemiepiphyseodesis is commonly used to correct a coronal plane knee deformity during childhood. Since 2007 Blount staple method has been replaced by the eight-Plate Guided Growth System. We retrospectively analysed the indications, results and complications of the older Blount staple method so as to compare them with the newer eight-Plate Guided Growth system. MATERIAL AND METHODS In the period from 2009 to 2019, a total of 98 lower extremities of 54 patients were treated by hemiepiphyseodesis. Lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA) and mechanical axis deviation (MAD) were measured before and after the correction. We focused on the location of hemiepiphyseodesis (distal femur/proximal tibia/both), the operative time and compared the results of implanting 2 or 3 Blount staples. RESULTS The primary correction of valgus knee deformity was achieved in 97%, of which only partial correction was observed in 9.2% and slight overcorrection in 6.1%. A total of 4 patients (4.1%) underwent subsequent corrective osteotomy. The mean LDFA increased from 80° to 86°, while the mean MPTA decreased from 94° to 92°. The mean MAD decreased from 23 mm to 3 mm. The reported complication rate was 5.1%, including four cases of loosening of staples and one case of superficial infection. DISCUSSION It has been verified that the LDFA reduction correlates with staple implantation into the distal femur, conversely the increase in the MPTA correlated with the implantation of staples into the proximal tibia or into both locations. The number of implanted staples (2 or 3) did not affect the size of the resulting correction, but the operative time was statistically significantly shorter when 2 instead of 3 staples were implanted. CONCLUSIONS Blount staple hemiepiphyseodesis is an older method, but it still gives very good results with a low rate of complications. The operating time can be shortened by using 2 staples only, with the same correction effect. The LDFA and MPTA parameters are helpful in identifying the location of hemiepiphyseodesis. The key to success of treatment still remains in correct timing of the implantation of staples with sufficient growth potential. Key words: hemiepiphyseodesis, guided growth, valgus knee deformity, Blount staple.

Analysis of Gene Expression of Pseudoarthrosis Tissue in Congenital Short Femur, Initial Study and First Exprerience.

PURPOSE OF THE STUDY Although the congenital short femur is morphologically well characterized, changes at the molecular level have not been described in the literature so far. The absence of such information, along with the unknown aetiology of the defect, was the motivation for analysing angiogenesis and osteogenesis in the pseudoarthrosis (false joint) tissue in PFFD patients compared to physiological bone. The authors expected differences in gene expression, particularly in the quantity of expressed genes. MATERIAL AND METHODS A piece of bone was removed during an elective surgery procedure, placed in an RNA stabilization reagent, which prevents RNA degradation, and deep frozen. Thereafter, RNA was isolated and the profile of transcription was analysed by biochip analysis (SuperArray Bioscience Corporation). In total, it is possible to detect 113 genes of osteogenesis and angiogenesis. From the end of 2005 until the end of 2008, samples of 7 patients with PFFD and 3 physiological bone samples were examined. Several analyses were repeated to confirm the results; in total 13 chips for osteogenesis and 11 chips for angiogenesis expression were used. RESULTS Differences in the quantity and representation of the genes were noted. Some genes were considered over-expressed in PFFD tissue compared with the control sample (e.g. the gene for calcitonin receptor, collagen XII, I alpha 2, collagen II, IX, FGFR2, fibronectin, integrin) and other genes under-expressed (e.g. the gene for annexin A5, collagen XVIII alpha1, collagen I alpha1, cathepsin K, FGFR1, FGFR3, IGF2, VEGFB). CONCLUSIONS The differences in gene expression confirmed the authors' hypothesis. So far, the results cannot be generalized; this is the first step for follow-up experiments to confirm the suggested information and to integrate it with clinical findings, such as the alternative blood supply of affected extremity in some patients. Key words: proximal femoral focal deficiency, gene expression, microarray analysis, angiogenesis, osteogenesis.

[Two-Stage Revision for Periprosthetic Infection of the Total Hip Arthroplasty: a Comparison of Two Methods]. / Srovnání klinických výsledku skupiny pacientu neartikulovaného a artikulovaného spaceru pri dvoudobé reimplantaci TEP kycelního kloubu pro periprotetický infekt.

PURPOSE OF THE STUDY The purpose of the study is a retrospective comparison of results of the two-stage revision total hip arthroplasty using a non-articulating and an articulating spacer to treat periprosthetic joint infection (PJI). Two basic hypotheses are evaluated: (1) the clinical outcomes of the patients treated with "hand made" articulating cement spacer are better than in non-articulating patient's group in two-stage revision for PJI of the total hip arthroplasty and (2) PJI recurrence is higher in the group of patients treated with an articulating spacer group. MATERIAL AND METHODS The evaluated group consists of a total of 57 patients (23 women, 34 men) with the mean age of 61.2 years. Group A of 39 patients were treated by two-stage revision using the "hand-made" articulating cement spacer and Group B of 18 patients were treated using the non-articulating spacer. Both the groups were evaluated retrospectively in the reference period: preoperatively and two years after the surgery using the Harris Hip Score (HHS) clinical assessment. The revision surgery for acute and chronic complications of treatment, length of hospitalization, and the PJI recurrence were evaluated for both the groups. RESULTS The resulting HHS clinical reviews were pre-operatively 43.59 points in both the groups with postoperative improvement up to 81.74 points. The mean preoperative HHS scores were 41.67 points (Group A) and 47.77 points (Group B) and two years after the surgery they were 83.43 points (Group A) and 78.08 points (Group B) (two-tailed t-test, p-value = 0.042). In Group A a total of seven revisions were performed in the interval between the two-stage revision (4x recurrent dislocation, 2x persistent infection, 1x spacer fracture). In Group B one patient was revised for persistent infection. In the two-year period after the operation, a relapse of PJI was recorded in 5 patients in Group A (12.8%) and in 1 patient in Group B (5.6%) (Chi-square test, p-value = 0.41). The average time of hospitalization was 51.58 days, whereby 49.72 days and 55.61 days on average for Group A and B respectively (p-value = 0.53). DISCUSSION According to recent studies, the advantage of motion preservation in articulating cement spacers can be complicated by recurrent dislocations, implant migration, periprosthetic fractures or recurrent joint replacement infections, which can further prolong the treatment and worsen the final clinical results. An alternative treatment option is the application of a nonarticulating spacer maintaining the advantage of local administration of antibiotics and reducing the dead space formed by the infected implant removal. Discussed is mainly the choice of the method in case of muscle disorder or presence of segmental bone defects. CONCLUSIONS The results demonstrate the better clinical outcomes and the higher revision rate of patients with an articulating cement spacer in two stage revision. We didn't find any differences between the risk of PJI recurrence in both groups. Key words:periprosthetic infection, total hip replacement, cement spacer, two stage revision, articulating spacer, nonarticulating spacer.

[RHD genotyping from cell-free fetal DNA circulating in pregnant women peripheral blood and sensitivity assessment of innovated diagnostic approaches for introduction into the clinical practice]. / Stanovení RHD genotypu plodu z plazmy periferní krve tehotné zeny a posouzení citlivosti nových diagnostických postupu pro zavedení do klinické praxe.

OBJECTIVE: Introduction of fetal RHD genotyping from cell-free fetal DNA circulating in the peripheral blood of pregnant women to clinical practice. Sensitivity assessment of innovated method using range of dilution series and internal control of amplification. DESIGN: Procedure creating of noninvasive determination of fetal RHD genotyping from blood plasma of pregnant women. Detection of limit of minority representation RHD+/- sample in the RHD-/- sample. SETTING: University Hospital Olomouc, Institute of Medical Genetics and Fetal Medicine, Clinic of Obstetrics and Gynecology, Transfusion Department. METHODS: TaqMan Real-Time PCR without an internal amplification controls. Optimization and calibration of RHD genotyping using RHD multiplex by TaqMan Real-Time PCR with an internal amplification control and by minisequencing (Snapshot - multiplex) with an internal amplification controls. RESULTS: RHD positive or negative fetuses were determined by amplification curves from Real-Time PCR system that matches the parameters for the evaluation of the output data using series of amplification and contamination parallel controls. TaqMan based Real-Time PCR and minisequencing (SNaPshot) based quantification were able to detect 0.22% of artificial RHD+/- sample diluted in RHD-/- sample. In addition, SNaPshot assay is suitable for heterozygozity and homozygozity recognition. CONCLUSION: Current established and routinely used procedure is based on the detection of exon 7 of the RHD gene and on the series of parallel amplification and contamination controls. Both newly developed methods could be, after validation of the larger set of control samples, introduced into clinical practice.

[Efficiency of conservative treatment by overhead traction in developmental dysplasia of the hip]. / Úspesnost konzervativní lécby vývojové kycelní dysplazie metodou "over-head trakce"

PURPOSE OF THE STUDY: Developmental dysplasia of the hip (DDH) is a disorder affecting the development of the acetabulum, proximal femur and joint capsule. The objective of this study was to analyse the results of closed reduction by overhead traction in subluxated and dislocated hips. MATERIAL AND METHODS: In the period from 2002 to 2007, a total of 109 patients (124 hips) were treated by overhead traction. The indication criteria included adductor contracture and misalignment of the hip joint assessed as classes III A, III B or IV according to the Graf ultrasonographic classification. There were 96 (88 %) girls and 13 (12 %) boys. The left side was more frequently affected, at a ratio of 83 to 41, and bilateral DDH was found in 15 patients. Teratologic dislocations were not included in the study. The patients were divided into two groups according to age and the place of primary diagnosis. The children primarily diagnosed at our hospital Na Bulovce where placed in group 1, the patients diagnosed outside our hospital fell in group 2. The average age at the beginning of treatment was 2.2 months in the first group and 6 months in the second group. Our method of overhead traction consists of two phases. Horizontal traction is applied for two weeks in phase 1; the hips are then flexed beyond 90 degrees and gradually abducted for another 4 weeks in phase 2.The outcome of traction is examined by arthrography and a spica cast is applied in the safe zone.We observed the relation between the Graf classification and arthrograpy. The outcome of closed reduction was compared between the groups and the development of avascular necrosis was observed. The hips treated by open reduction were assessed in a different study. RESULTS The efficiency of closed reduction was 84 % in group 1 and 60 % in group 2 in which also two cases of recurrent dislocation were found. No significant differences between the Graf classification and the final arthrographic findings were recorded in either group (p ≥ 0.05). Avascular necrosis as defined by the Salter criteria was not diagnosed. DISCUSSION: Early reduction is essential to ensure normal development of the hip joint. Overhead traction therapy for misalignment of the hip joint is a safe method reducing damage to the femoral head. Its principle lies in gradual distraction of the contracted muscles and joint capsule with a concomitant change in traction direction in order to achieve a reduction manoeuvre without placing increased stress on the femoral head. CONCLUSIONS: Overhead traction is the method of choice for management of Graf's class III A, III B and IV hips. For the efficiency of treatment, an early diagnosis and a correct indication are essential. To avoid complications such as avascular necrosis, it is necessary to observe the principle of a safe zone.

[The Ponseti method of treatment of congenital clubfoot--first experiences]. / Ponsetiho metoda v lécení pes equinovarus congenitus--první zkusenosti.

PURPOSE OF THE STUDY: To provide a detailed description of the Ponseti method and report the first results of its use, including factors that played a role. MATERIAL AND METHODS: In the 2005-2007 period, 91 patients with idiopathic rigid clubfoot (133 feet) were treated by the Ponseti method. The group comprised 62 boys and 29 girls. In most patients the Ponseti method was used as primary treatment, or by 3 months of age when previous treatment failed. In five children this treatment was started between the 3rd and 8th months of age. The result were evaluated by the criteria described by Richards et al., who distinguished four groups. The result was regarded as good when a permanent plantigrade foot was achieved (group 1). Plantigrade feet likely to require posterior release later were considered indeterminate rusults (group 2). Feet that needed posterior release, anterior tibial muscle transfer or lateral column shortening fell in the fair result group (3). Feet requiring complete subtalar release were classified as poor results (group 4). The results achieved in each year were statistically evaluated using Fisher's test (p<0.05). RESULTS: The overall evaluation for 3 years showed good results in 70%, indeterminate in 7.5%, fair in 6.76% and poor in 15.8% of the treated feet. A detailed analysis for each year revealed that, in 2005, good results (50%) were recorded in a significantly lower number of feet than in 2006 (72.2%; p=0.032) and 2007 (93%; p<0.001). On comparison of the years 2006 and 2007, good results in 2007 were found in a significantly higher number of feet than in 2006 (p=0.019). The poor results were due to 1) very rigid feet (6%); 2) initial problems with availability of Denis-Brown splints (19 feet; 14.5%); 3) problems with shoes not made to custom and not fitting patient's little feet (20 feet; 15%) 4) faulty techniques of correcting the deformity (4 feet); 5) poor family cooperation in compliance with the bracing protocol (15 feet; 11.2%). Some of the factors were combined. A delayed beginning of the treatment had no significant effect on the results. DISCUSSION: Our 3-year results of clubfoot treatment, by which plantigrade foot position was acheved on average in 77.5% of the patients, are in agreement with those achieved outside Ponseti centres. However, there were clear differences, with the worst results in 2005. The results comparable with those of Ponseti and his co-workers were achieved by us only in 2007. In accordance with the findings of Richards et al. we suggest that the percentage of short-term good results can change insignificantly within 4 years because of increased recurrence of deformities. CONCLUSIONS: Although our initial results were worse than reported in the literature, it can be concluded that the Ponseti method of treating idiopathic clubfoot is more efficient that the methods used previously and can be recommended as an efficient, safe and economical technique. Good compliance with the protocol improves the therapeutic results.

Hydrogen peroxide in the breath of rats: the effects of hypoxia and paraquat.

The hypothesis that oxidative stress can be induced by hypoxia was tested by measuring the concentration of hydrogen peroxide by a luminometric technique in the breath samples of rats exposed to hypoxia and paraquat. The group of animals (n=15) exposed to normobaric hypoxia (10% O2) for three days had an increased amount of H2O2 (200%, P<0.001) in their breath in comparison to control animals. After 7 days of recovery in air, the exposed animals still produced significantly increased levels of H2O2 (152%, P<0.001). Paraquat administration was used as a positive control, since it is a redox cycling compound producing free radicals. In the animals treated with a toxic dose of paraquat, the peak H2O2 production was observed 5 h after i.p. injection (156%, P<0.02). Within the next 2 h it decreased to the control level and stayed constant for 48 h, when the animals began to die. It is suggested that H2O2, observed in the breath samples, is a product of a metabolic pathway that could itself be sensitive to oxidative damage.

Production of hydrogen peroxide by peritoneal macrophages from rats exposed to subacute and chronic hypoxia.

Hydrogen peroxide production was measured in non-elicited rat peritoneal macrophages using luminol-dependent chemiluminescence (LDCL). Isolated cells were activated by a chemotactic peptide (FMLP) or by a phorbol ester (PMA) or by the combination of both. A hundred-fold higher LDCL intensity was achieved with PMA relative to FMLP. However, when FMLP was added subsequently to PMA it produced approximately the same response as did PMA. These measurements were carried out with cells isolated from controls and from animals exposed to normobaric hypoxia (10% O2) for 3 hours, 3 days, or 21 days. Hypoxia had a dual effect. Acutely (within 3 hours) it attenuated the production of hydrogen peroxide triggered by PMA, whilst during longer exposure (3 or 21 days) it increased the response induced by FMLP. Hypoxia can thus modulate the capacity of respiratory burst in peritoneal macrophages.

Thyroxine treatment increases the hypoxic pulmonary vasoconstriction in isolated lungs from thyroidectomized rats.

The possibility that changes in energy metabolism are involved in oxygen sensing during hypoxic pulmonary vasoconstriction was tested indirectly by measurement of hypoxic-pressor reactivity in lungs isolated from rats with low and high levels of plasma thyroxine. In the first study, male rats were treated for one week after thyroidectomy with 50 micrograms (n = 6) or 100 micrograms (n = 6) thyroxine per 100 g body weight (b.w.) daily or with solvent (n = 6). The lungs were isolated and perfused at constant flow with salt-albumin solution. They were ventilated with air +5% CO2 in a humid chamber at 38 degrees C. The dose-pressor response to hypoxia and angiotensin II were measured. In the second study, thyroidectomized male rats were treated similarly with 100 micrograms thyroxine (n = 7) or solvent (n = 6) and isolated lungs were perfused with homologous blood obtained from thyroidectomized blood donors treated in the same manner. Then the dose-pressor responses to hypoxia and K+ were elicited. The hypoxic-pressor responses were bigger in thyroxine than in solvent-treated rats. The response to angiotensin II and K+ was not affected by thyroxine treatment. The results are consistent with the idea that hypoxic-pressor reactivity varies directly with the metabolic rate of lung tissue.

[Postnatal development of the Hering-Breuer reflex in the rat]. / Développement postnatal du réflexe de Breuer-Hering chez le rat.

The intensity of the Breuer-Hering inflation reflex was studied in newborn (1 day old), in young (8 days old) and in adult rats (90 days old) under urethane general anaesthesia (1.3 g/kg i.p.). The inflation pressure was adjusted with the aid of a water-valve. The reflex was present in all 3 age groups. An inflation pressure of 0.2 kPa applied in the course of expiration produced a long lasting apnoea in newborn rats which lasted 48 normal respiratory cycles. An inflation pressure of 0.5 kPa in young rats induced an apnoea lasting for only 3 normal respiratory cycles, whereas a pressure of 1 kPa in adult rats led to an apnoea which lasted for 20 normal respiratory cycles. The compliance of the respiratory system in relation to lung weight is approximately 5 times higher in adult rats compared with that of newborn rats. It is approximately double in comparison with young rats. The pressures of inflation mentioned in the 3 age categories can be considered as equieffective from the point of stimulation pulmonary stretch receptors. It can be concluded from these findings that the reflex of Breuer-Hering in newborn rats is more potent in comparison with adult rats, but it is lower in young rats at the age of 8 days. It is suggested that the differences observed are due to functional and anatomical maturation.

Dynamics of eye fundus changes in two types of experimental brain oedema.

During the experimentally induced cerebral oedema and intracranial hypertension the eye fundus changes have been evaluated in generally anaesthetized rats. Cerebral oedema was caused either by means of an osmotic or cryogenic method. Dynamics of the observed ocular changes were indirectly correlated with the origin, development and regression of the cerebral oedema caused by both different etiologic factors.

The role of vagal nerves in changes of functional residual lung capacity during acute hypoxia.

Functional residual capacity of the lungs (FRC) was measured by a plethysmographic method in anaesthetized, intubated rats breathing air or a hypoxic mixture (10% O2 in N2), before and after bilateral cervical vagotomy. Inhalation of the with intact vagi, the drop in Pao2 was accompanied by a significant rise of FRC; after hypoxic mixture led to the same decrease in Pao2 before and after vagotomy. In rats vagotomy, hypoxia did not affect the FRC. The vagal nerves are thus apparently necessary for the increase of FRC during hypoxia in the rat.

Effect of vagal cooling on lung functional residual capacity in rats with pneumonia.

We examined the effect of cold vagal block on the functional residual lung capacity (FRC) in control rats and in rats with experimental pneumonia induced by intratracheal administration of the herbicide paraquat. The measurements were performed in a body plethysmograph in anaesthetized and intubated rats. Rats with pneumonia had tachypnoea and increased minute ventilation. Their FRC was 3.6 +/- 0.7 ml in comparison with 2.5 +/- 0.6 ml in controls (mean +/- SD). Cooling the cervical vagi, so that the Hering-Breuer inflation reflex was abolished (approximately 8 degrees C), resulted in a marked decrease of the rate of breathing and an increase of tidal volume in both groups of animals. The value of FRC did not change during vagal cooling (3.7 +/- 0.9 ml in rats with pneumonia, 2.8 +/- 0.8 ml in controls). In rats with model pneumonia, bilateral cervical vagotomy was followed by a normalization of the FRC (2.3 +/- 0.7 ml). In control animals, the FRC did not change after vagotomy (2.5 +/- 0.6 ml). We conclude that increased FRC in rats with paraquat pneumonia depends on intact conduction through thin, slowly conducting vagal fibres.