Monozygotic Twins with Legg-Calvé-Perthes Disease and with Non-Identical Lumbosacral Malformation: a Case Report and Literature Review.

The authors present the cases of monozygotic male twins with right-sided Legg-Calvé-Perthes disease (LCPD) with different formation of the lumbosacral junction. This is likely the fi rst description of a lumbosacral junction formation disorder associated with identical twins who were both treated for LCPD as children. The disease began at 6 and 9 years of age and during treatment as well as in adulthood signifi cantly different bone formation of the lumbosacral transitional vertebra, was observed in both brothers. Twin A has a unilateral right-sided fusion of the enlarged L5 transverse process with the ipsilateral sacral ala, twin B has a complete sacralization of the fi fth lumbar vertebra. The LCPD treatment outcomes in the twins were consistent with the results from large studies, i.e., age at the time of LCPD onset is the main factor infl uencing the prognosis, however the morphological difference in the transitional vertebrae in these monozygotic twins was signifi cantly. Key words: lumbosacral transitional vertebra, lumbosacral junction formation, sacralization of lumbar vertebra, megatransverse of vertebra L5.

[Custom-Made 3D Printed Titanium Acetabular Component: Advantages and Limits of Use]. / Individuální titanová acetabulární komponenta vyrobená 3D tiskem: výhody a limity pouzití.

The authors report on three cases in which a custom-made 3D printed titanium acetabular component of total hip arthroplasty was used to manage an advanced acetabular bone defect with pelvic discontinuity. The implant surface structure impeded long-term bone integration. Nonetheless, the stable bridging of the acetabular defect resulted in full integration of impacted bone allografts at the base of the implant. The pelvic continuity was restored within 12 months after surgery, and thus the acetabulum was prepared for potential further implantation of a standard revision acetabular component. Only one of the three female patients underwent a revision surgery at 18 months after surgery, the other two female patients were satisfied to such a degree with the clinical outcome at 6 years and 5 years, respectively, after surgery that they refused to undertake the revision surgery, despite X-ray images showing signs of loosening of the custom-made titanium acetabular component. The authors concluded that the implantation technique of three-point fixed custom-made 3D printed acetabular component made of titanium combined with impaction grafting of the acetabular base is a good alternative in managing the advanced bone defects of acetabulum with pelvic discontinuity after the failure of total hip arthroplasty. Even though inadequate surface porosity of the thus produced component did not allow its permanent osteointegration, the assembly was stable enough to allow the bone allografts to rebuild and restore continuity of the pelvis and facilitated future implantation of the standard revision acetabular component. Key words: 3D printing, individual acetabular component, titanium, total hip prosthesis, revision hip arthroplasty, acetabular reconstruction, custom-made implants.

[Biomechanika osteosyntézy periprotetických zlomenin femuru po aloplastice kycelního kloubu]. / Biomechanics of Osteosynthesis in Periprosthetic Femoral Fractures Following Total Hip Arthroplasty.

Periprosthetic femoral fractures around the femoral stem of a hip prosthesis constitute a serious challenge. The number of these fractures, associated with a high failure rate and a high number of overall complications, including higher mortality, has been on an increase worldwide. Stable femoral stems are indicated for osteosynthesis, while in case of loosening the method of choice is the replacement by a revision implant. The aim of osteosynthesis of periprosthetic femoral fractures is a stable fixation with soft tissue preservation which results in faster union allowing the patient to return to pre-injury activities. Biomechanical studies on cadavers or on synthetic models and computer simulations make it possible to evaluate the fixation strength in various types of implants in dependence on fracture characteristics and bone quality, but cannot be substituted for clinical trials since there is no direct proportion between fixation rigidity and fracture union. Fundamental principles that shall be followed in osteosynthesis of periprosthetic fractures can be deduced from the available studies. Proximal fixation by screws or a combination of screws and cables are biomechanically more advantageous than the Ogden fixation by cerclage wires or cables. Bicortical fixation enabled by state-of-the-art implants of LAP-LCP or NCB type represents a significantly more stable construction compared to monocortical fixation and led to reduced use of structural allografts. Better stability can be achieved by "double plating" technique which is applied especially in revision surgeries, but also in osteoporotic periprosthetic fractures with a defect zone. In these cases, osteosynthesis with long plates is recommended, bridging the entire femur, i.e. distally with femoral condyles fixation since this prevents the risk of a fracture below the plate. In shorter plates, this risk created by stress concentration at the end screw is amplified when a distal bicortical locking screw is used. That is why it is beneficial to reduce this stress by a monocortical screw or with the use of a conventional screw. Adherence to the principles regarding the position, type and number of screws constitutes the key parameter of successful osteosynthesis of periprosthetic fractures. Key words: hip joint, arthroplasty, periprosthetic fractures, biomechanics of osteosynthesis.

[Mechanical Testing of Tendons Sutured with Newly Developed Biomaterial]. / Mechanické testování slach po suture nove vyvinutým biomateriálem.

PURPOSE OF THE STUDY Tendon injuries continue to be a highly topical issue. Research and clinical activities in this area aim to achieve an optimal repair of the damaged tendon. Such suture is characterised by maximum tensile strength, resistance to gapping at the repair site, preservation of smooth surface, prevention of adhesions and facilitation of fast rehabilitation and active tendon movement. The suture as such is required to show mechanical resistance in particular. Considered optimal is the use of core suture of the tendon in combination with epitendinous suture. The group of researchers has for several years already been exploring new materials. They can contribute to better balance between adequate mechanical strength of the suture and biological support of healing. MATERIAL AND METHODS The study was carried out as an ex vivo experiment on porcine tendon models. A tendon segment was obtained from slaughtered animals and a total rupture of the tendon was imitated by sharp cutting of its central portion. Subsequently, the tendon was repaired by Adelaide suture using coated braided polyester (Ethibond) and two types of new polyamide 6 based (PA6) sutures. The first suture was designed as an unabsorbable polyester core (PES silk) surrounded by absorbable PA6 nanofibres. The second suture was created by braiding a PES silk yarn and two viscose yarns with PA6 nanofibres into a composite surgical suture. As a part of the study also examined was the tensile strength of suture with the use of other stitches, effect of the shape of the needle s point on the tensile strength of the suture and the effect of secured mattress peritendinous suture. The tensile strength of the suture was tested until failure and the achieved maximum load was monitored. RESULTS The PES core yarn with PA6 nanofibre braiding showed lower tensile strength (28.5 ± 5.2 N) than the yarn braided from one PES yarn and two viscose yarns with PA6 nanofibres (45.7 ± 6.7 N). Both newly developed sutures, however, fail to achieve the tensile strength of Ethibond (100.3 ± 19.1 N). In case of Ethibond suture using various types of stitches, the lowest tensile strength was observed in McLarney 4-strand core suture (68.8 ± 18.7 N). A higher tensile strength was achieved by Adelaide 4-strand core suture (83.6 ± 11.2 N). The highest tensile strength was seen in 6-strand core Savage suture (147.4 ± 22.7 N). When the effect of the type of needle was tested, a statistically significant difference between the taper point needle (72.0 ± 7.0 N) and reverse cutting needle (63.3 ± 9.6 N) was observed. In case of McLarney suture the epitendinous stitch increased the tensile strength by 46.2% and in case of Adelaide suture by 48.3%. CONCLUSIONS For tendon core suture, the use of sutures with multiple longitudinal segments seems more appropriate. The epitendinous suture can considerably reinforce the basic load-bearing core suture. Also observed was not an insignificant effect of the needle profile on the resulting tensile strength of the suture. In materials developed by us, more suitable seems to be the design of braiding of absorbable nanofibers with a load-bearing non-absorbable yarn. While the mechanical tensile strength of new materials is lower, the benefits are expected in the form of biological support of healing. Moreover, the nanofibers can be used as a carrier of biological and therapeutic substances. Further improvement of mechanical properties of the newly developed biomaterial can be foreseen if the material of the load-bearing non-absorbable yarn is changed or the load-bearing yarn and nanofibres ratio modified. This pilot study shall use the findings for further development and modification of new materials in basic research and shall also verify the biological aspects and the course of healing in in vivo studies. Key words: tendon, suture, pig, biomaterials, nanofibres, mechanical testing, healing, polyester, Adelaide.

[Outcomes and Complications of Surgical Treatment for LSS at 1-Year Follow-up - Prospective Study]. / Výsledky a komplikace po operacním resení LSS v horizontu jednoho roku ­ prospektivní studie.

PURPOSE OF THE STUDY Lumbar spinal stenosis (LSS) is a serious and fairly frequent disorder with prevalence increasing with age which often results in a disability. The surgical procedures are often very risky due to the greater age of patients with severe stenosis and their comorbidities. The study aimed to assess the functional outcomes and complications in patients who underwent surgical treatment for LSS at one year postoperatively and to identify the differences in the functional outcomes, if any, in dependence on the number of operated segments. MATERIAL AND METHODS It was a prospective study which included 33 patients who underwent surgery at the authors department from 1 November 2015 to 1 October 2016 for LSS, the mean age of patients was 69.5 (43-83) years. The surgery was indicated based on the clinical examination, radiography and MR imaging and consisted in posterior decompression with or without stabilisation and fusion. Pre- and post-operatively, a neurological examination and evaluation of patient difficulties were performed by: VAS - particularly for low back pain (VAS-LB) and lower limb pain (VAS-LL), Oswestry Disability Index (ODI) and Swiss Spinal Stenosis Questionnaire (SSSQ). The evaluation was done at a half year and one year after the surgery. The authors made comparisons in dependence on the number of treated segments (1-2, 3-5 and Th-S stabilisation). RESULTS A significant improvement of all the followed-up parameters was reported at one year postoperatively. At one year after the surgery, the VAS-LB score showed a decrease by 2.39 (p = 0.001), the VAS-LL by 3.26 (p < 0.001), while a decrease by 2 or more points is considered clinically significant. When evaluating the SSSQ questionnaire, a decrease in subjective difficulties (SSSQ-S) was by 0.89 (p < 0.001), in physical function (SSSQ-F) by 0.87 (p < 0.001). In this questionnaire, the satisfaction rate with the surgery was 2 - i.e. somewhat satisfied. Altogether 76% of patients were very or somewhat satisfied, no one was very dissatisfied. When evaluating the ODI, an improvement by 20.6% (p < 0.001) was reported. The authors identified neither any significant differences in the outcomes at a one-year follow-up in dependence on the length of stabilisation, nor any significant differences between the six-months and one-year follow-up. Intraoperative complications occurred in 18%, early postoperative complications in 6% of patients. The ASD developed in 9% within one year. DISCUSSION The authors confirmed a significant improvement of the followed-up parameters (VAS-LB, VAS-LL, SSSQ, ODI) which corresponds with recent literature. The decrease in VAS and ODI in the authors study is more marked than the outcomes stated in literature. The authors outcomes clearly show that there is no correlation with the length of stabilisation and the number of decompressed segments. Conversely, the rate of complications was higher in this group than the rates stated in literature, but majority of complications had no consequences for the patients. CONCLUSIONS In the group of patients with a one-year follow-up the authors confirmed that surgical procedures will result in reduced subjective difficulties of patients, reduced pain and improvement of physical function. A significant improvement of all the followed-up parameters was reported. The authors did not confirm the correlation between the postoperative improvement and the number of treated segments. Key words:lumbar spinal stenosis, quality of life, post-operative outcomes, complications.

[Use of the Peptigel with Nanofibres in the Bone Defects Healing]. / Vyuzití peptigelu s nanovlákny k lécbe defektu kostní tkáne.

INTRODUCTION Traumatic bone injuries or pathological processes may sometimes result in very extensive bone defects. Currently, the standard procedure applied in clinical humane as well as veterinary medicine to fill a bone defect is the autogenous bone graft which, however, necessitates a more invasive procedure for the patient and in the cases of extensive defects it fails to provide adequate amount of graft. Synthetic bone replacements can be used with no further burden for the patient and can simultaneously be used as the carriers for bioactive molecules or therapeutic drugs. For clinical use, an easy and simple application is one of the requirements that have to be taken into consideration. These requirements are best satisfied by preparations in the form of gel, which may be injected into the defects of various shapes even through minimal surgical approach. MATERIAL AND METHODS Synthetic transparent PGD-AlphaProA hydro-peptide-gel was used as a basis to develop a composite hydrogel scaffold. This gel was enriched by cryogenically ground poly- -caprolactone nanofibers (PCL) in a ratio of 1 ml of gel to 16 µg of nanofibres. In experimental animals (laboratory rat Wistar, n=20), a single regular circular defect of 1.5 mm in diameter was drilled by a low speed drill machine across the whole width of distal femur diaphysis, identically in both the hind legs. In the right hindleg, this defect was filled by injection of 0.05 ml of the composite peptide gel with nanofibers (experimental defect). In the contralateral limb a similar defect was left untreated, without filling (control defect), for spontaneous healing. The group of experimental animals was subsequently divided into four sub-groups (A, B, C, D) for the purpose of further follow-up. One week after the surgical implantation, in the first group of experimental animals (Group A; n = 5) lege artis euthanasia was performed, a radiological examination of both the hind legs was carried out and a sample of the bone from both the control and experimental defect was collected for histologic examination. The other groups of experimental animals were evaluated similarly at 2, 4 and 6 weeks after the surgical procedure (Group B, C, D; n = 5). These groups of experimental animals were assessed using various histological techniques by two independent pathologists. RESULTS A difference between the control and the experimental bone defect was observed only at the healing stage at two weeks after the implantation, when a tendency for greater formation of new bone trabeculas was seen in the defect treated with the composite hydro-peptide-gel with PCL nanofibers. The results show a slightly higher angiogenesis and cellularity at the bone defect site with an increase of newly formed bone tissue and faster colonisation of lamellar bone structures by bone marrow cells at early stages of the healing process (1-2 weeks old defect). In the experimental and control groups, at the later stage of healing (4-6 weeks old defect), the process of healing and bone modelling at the defect site shows no detectable morphological differences. CONCLUSIONS The experimental use of hydro-peptide-gel with PCL nanofibers in vivo in laboratory rats shows very good applicability into the defect site and, compared to the untreated defect within two weeks after the implantation, accelerates the bone healing. This fact could be an advantage especially at the early stage of healing, and thus accelerate the healing of more extensive defects. Key words: peptide gel, polycaprolactone, PCL, replacement, bone, healing, scaffold, nanofibers, biomaterial.

[Comparison between the Range of Movement Canine Real Cervical Spine and Numerical Simulation - Computer Model Validation]. / Porovnání rozsahu pohybu reálné krcní pátere psa s pocítacovou simulací ­ validace pocítacového modelu.

PURPOSE OF THE STUDY In developing new or modifying the existing surgical treatment methods of spine conditions an integral part of ex vivo experiments is the assessment of mechanical, kinematic and dynamic properties of created constructions. The aim of the study is to create an appropriately validated numerical model of canine cervical spine in order to obtain a tool for basic research to be applied in cervical spine surgeries. For this purpose, canine is a suitable model due to the occurrence of similar cervical spine conditions in some breeds of dogs and in humans. The obtained model can also be used in research and in clinical veterinary practice. MATERIAL AND METHODS In order to create a 3D spine model, the LightSpeed 16 (GE, Milwaukee, USA) multidetector computed tomography was used to scan the cervical spine of Doberman Pinscher. The data were transmitted to Mimics 12 software (Materialise HQ, Belgium), in which the individual vertebrae were segmented on CT scans by thresholding. The vertebral geometry was exported to Rhinoceros software (McNeel North America, USA) for modelling, and subsequently the specialised software Abaqus (Dassault Systemes, France) was used to analyse the response of the physiological spine model to external load by the finite element method (FEM). All the FEM based numerical simulations were considered as nonlinear contact statistic tasks. In FEM analyses, angles between individual spinal segments were monitored in dependence on ventroflexion/ /dorziflexion. The data were validated using the latero-lateral radiographs of cervical spine of large breed dogs with no evident clinical signs of cervical spine conditions. The radiographs within the cervical spine range of motion were taken at three different positions: in neutral position, in maximal ventroflexion and in maximal dorziflexion. On X-rays, vertebral inclination angles in monitored spine positions were measured and compared with the results obtain0ed from FEM analyses of the numerical model. RESULTS It is obvious from the results that the physiological spine model tested by the finite element method shows a very similar mechanical behaviour as the physiological canine spine. The biggest difference identified between the resulting values was reported in C6-C7 segment in dorsiflexion (Δφ = 5.95%), or in C4-C5 segment in ventroflexion (Δφ = -3.09%). CONCLUSIONS The comparisons between the mobility of cervical spine in ventroflexion/dorsiflexion on radiographs of the real models and the simulated numerical model by finite element method showed a high degree of results conformity with a minimal difference. Therefore, for future experiments the validated numerical model can be used as a tool of basic research on condition that the results of analyses carried out by finite element method will be affected only by an insignificant error. The computer model, on the other hand, is merely a simplified system and in comparison with the real situation cannot fully evaluate the dynamics of the action of forces in time, their variability, and also the individual effects of supportive skeletal tissues. Based on what has been said above, it is obvious that there is a need to exercise restraint in interpreting the obtained results. Key words: cervical spine, kinematics, numerical modelling, finite element method, canine.

[Management of Osteochondral Lesions of the Ankle Joint by Implantation of Autologous Chondrocytes]. / Lécba osteochondrálních lézí hlezenního kloubu metodou implantace autologních chondrocytu.

UNLABELLED: PUPOSE OF THE STUDY The treatment of osteochondral lesions of weight-bearing joints remains a serious therapeutic challenge, largely due to the minimal ability of articular hyaline cartilage to regenerate. The authors present the long-term clinical and MRI results of treating deep chondral and osteochondral defects of the ankle joint by the method of implantation of autologous chondrocytes in the form of a solid chondrograft. MATERIAL AND METHODS The method of solid chondrograft implantation in the ankle joint was used in our Department from the year 2003. Between 2003 and 2013, this method was used in 31 patients, 16 men and 15 women. Their average age at the time of implantation was 29 years (16 to 50 years). The follow-up period ranged from 16 to 145 months (average, 57 months). The clinical outcome was evaluated using the Mazur questionnaire. At follow-up all patients underwent regular MRI examinations and the results were assessed on the basis of Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scores. Twelve patients required a second-look arthroscopy. RESULTS A comparison of the Mazur pre-operative scores with those obtained at 1, 2 and 5 years post-operatively showed marked improvement of ankle joint function. The average pre-operative value of 30.0 (based on responses of 31 patients) increased to the average of 89.7 (based on results of 11 patients). At 1 year post-operatively, the average MOCART score for a group of 18 patients was 78.3; at 5 post-operative years, the average value for nine patients examined was 77.0. Complete filling of defects at 1 year of follow-up was found in 88.1% and , at 5 years, it was recorded in 83.3% of the patients examined. DISCUSSION The articular hyaline cartilage is a highly differentiated tissue and its ability of repair is very limited. Therefore every damage to the articular surface should be regarded as a pre-arthritic condition// disease. Currently, there are several options of treating a damaged articular cartilage, but none of them makes its complete healing certain. A lot of studies concerned with longterm results of implanting autologous chondrocytes in the knee are available in the literature, but only few authors present long-term clinical and radiographic outcomes of ankle joint treatment similar to ours. CONCLUSIONS Based on our clinical and MRI results, the method of autologous chondrocyte implantation can be recommended since it has good long-term results, provides repair of articular cartilage and allows for patients' return to activities of daily living. KEY WORDS: chondral defect, hyaline cartilage, autologous chondrocyte, ankle joint.

Electrophysiological and histological changes of paraspinal muscles in adolescent idiopathic scoliosis.

PURPOSE: The pathogenesis of adolescent idiopathic scoliosis (AIS) remains poorly understood. To date, potentially involved local changes in the deep paraspinal muscles still remain unknown. METHODS: Needle electromyography (EMG) and muscle biopsy of paraspinal muscles at convexity and concavity of the AIS main thoracic curve were performed in 25 subjects. In this group, EMG was performed in 16 AIS subjects (12 females, 12-27 years), muscle biopsy in 18 AIS subjects (15 females, 11-31 years) compared to 10 non-scoliotic controls (6 females, 12-55 years). Samples of muscle tissue were removed during corrective surgery and were examined histologically, enzyme histochemically and immunohistochemically. Both methods of EMG and muscle biopsy were performed in 9 subjects (7 women, 12-27 years). RESULTS: Right curve convexity was found in 24 AIS subjects. Amplitudes of motor unit action potentials (MUPs) were significantly increased on the AIS curve convexity versus concavity. Turns, duration and phases of MUPs were without any significant changes. In all 18 subjects, the histological examination revealed muscle fiber redistribution with numerical predominance of type I on the curve convexity which strongly correlated with the progression of the Cobb angle. CONCLUSION: Our findings demonstrate significant changes of muscle fiber redistribution in the paraspinal muscles of AIS with increased proportion of type I on the convexity corresponding to a significantly higher amplitude of MUPs on the same side. A possible explanation of this alteration is a secondary adaptation due to chronic high load demand.

Risk comparison of bleeding and ischemic perioperative complications after acute and elective orthopedic surgery in patients with cardiovascular disease.

INTRODUCTION: The study objective was to ascertain the incidence of bleeding and ischemic complications related to acute and planned orthopedic surgery in patients with known cardiovascular diseases. MATERIALS AND METHODS: The study conducted between 2010 and 2013 enrolled 477 patients (289 women, 188 men) with a diagnosed cardiovascular disease or a history of thromboembolic event. Aside from gender, age, height and weight, the study observed other anamnestic data and perioperative laboratory test results that may impact on a bleeding or ischemic event. RESULTS: Two hundred seventy-two (57 %) patients had acute surgery, and 205 (43 %) patients had elective surgery. Complications arose in 55 (11.6 %) patients, 32 (6.9 %) had bleeding complications, 19 (4.0 %) ischemic complications, and both complications were experienced by 4 (0.8 %) patients. Bleeding developed in 14 (5.1 %) patients who had acute surgery, and in 22 (10.7 %) who had elective surgery. Twenty-two (8.1 %) patients having acute surgery and one (0.1 %) undergoing elective surgery suffered from ischemic complications. The incidence of bleeding complications was significantly higher in elective surgery (p = 0.026, OR 2.22), and when adjusted (general anaesthesia, gender, and use of warfarin), the difference was even higher (p = 0.015, OR 2.44), whereas the occurrence of ischemic complications was significantly higher in acute surgery (p = 0.005, OR 18.0), and when adjusted (age), the difference remained significant (p = 0.044, OR 8.3). CONCLUSIONS: The study noted a significantly higher incidence of bleeding complications in elective orthopedic surgery when compared with acute surgery. Conversely, the incidence of ischemic complications was significantly higher in patients having acute orthopedic surgery when compared with those operated on electively.

THA and TKA in patients with cardiovascular disease: What makes the risk of perioperative bleeding?

Backround: The purpose of the study was to ascertain the incidence of bleeding and ischaemic complications in patients with cardiac disease after total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: In total, 477 patients (289 women, 188 men) with known history of cardiac disease or thromboembolic disease treated with surgery in 2010-2013, were enrolled in the study. Perioperative prevention of thromboembolic disease using low-molecular-weight heparins was applied in all the patients. The data that could have an impact on the development of monitored perioperative complications, were observed. RESULTS: Complications occurred in 55 (11.6 %) patients: bleeding complications in 32, ischaemic in 19, and both in four patients. Complications were found in 13 (12.0 %) patients after THA and in 6 (9.5 %) patients after TKA. Bleeding complications were observed in 17 patients after THA and TKA, ischaemic in one, and both simultaneously in one patient.Bleeding complications occurred insignificantly more frequently after THA and TKA (p = 0.094); however, this difference was statistically significant after adjustment for risk factors (p = 0.003). On the contrary, ischaemic complications were significantly more frequent after other skeletal surgeries (p = 0.014). Nevertheless, this difference was not statistically significant after the adjustment (p = 0.880). The comparison of the risk of complications in patients after THA with that in patients after TKA showed no significant difference (p = 0.580). CONCLUSION: The study showed a significantly higher incidence of bleeding complications in patients after THA and TKA compared to other surgeries of the musculoskeletal system in patients with a history of cardiac disease. Bleeding complications cannot be detected in advance (Tab. 1, Ref. 16).

[Surgical Correction of Scoliosis: Does Intraoperative CT Navigation Prolong Operative Time?] / Operacní korekce skoliózy: prodluzuje peroperacní CT navigace trvání operace?

PURPOSE OF THE STUDY The aim of the study was to compare the duration of corrective surgery for scoliosis in relation to the intra-operative use of either fluoroscopic or CT navigation. MATERIAL AND METHODS The indication for surgery was adolescent idiopathic scoliosis in younger patients and degenerative scoliosis in middleage or elderly patients. In a retrospective study, treatment outcomes in 43 consecutive patients operated on between April 2011 and April 2014 were compared. Only patients undergoing surgical correction of five or more spinal segments (fixation of six and more vertebrae) were included. RESULTS Transpedicular screw fixation of six to 13 vertebrae was performed under C-arm fluoroscopy guidance in 22 patients, and transpedicular screws were inserted in six to 14 vertebrae using the O-arm imaging system in 21 patients. A total of 246 screws were placed using the C-arm system and 340 screws were inserted using the O-arm system (p < 0.001). The procedures with use of the O-arm system were more complicated and required an average operative time longer by 48% (measured from the first skin incision to the completion of skin suture). However, the mean time needed for one screw placement (the sum of all surgical procedures with the use of a navigation technique divided by the number of screws placed using this technique) was the same in both techniques (19 min). DISCUSSION With good teamwork (surgeons, anaesthesiologists and a radiologist attending to the O-arm system), the time required to obtain one intra-operative CT scan is 3 to 5 minutes. The study showed that the mean time for placement of one screw was identical in both techniques although the average operative time was longer in surgery with O-arm navigation. The 19- minute interval was not the real placement time per screw. It was the sum of all operative times of surgical procedures (from first incision to suture completion including the whole approach within the range of planned stabilization) which used the same navigation technique divided by the number of all screws inserted during the procedures. The longer average operative time in procedures using O-arm navigation was not related to taking intra-operative O-arm scans. The authors consider surgery with an O-arm imaging system to be a safer procedure and use it currently in surgical correction of scoliosis. CONCLUSIONS The study focused on the length of surgery to correct scoliosis performed using either conventional fluoroscopy (C-arm) or intra-operative CT scanning (O-arm) showed that the mean placement time for one screw was identical in both imaging techniques when six or more vertebrae were stabilised. The use of intra-operative CT navigation did not make the surgery longer, and the higher number of inserted screws provides evidence that this technique is safer and allows us to achieve good stability of the correction procedure. Key words: virtual CT guidance, O-arm, scoliosis, transpedicular screw.

[Fracture Type and Injury-to-Surgery Interval as Risk Factors for Avascular Necrosis of the Femoral Head after Internal Fixation of Intracapsular Femoral Neck Fracture]. / Typ zlomeniny a interval úraz-operace jako rizikové faktory pro vznik avaskulární nekrózy hlavice femuru po osteosyntéze intrakapsulárních zlomenin krcku.

PURPOSE OF THE STUDY: The aim of the study was to investigate the occurrence of avascular necrosis (AVN) of the femoral head following the osteosynthesis of intracapsular fracture of the femoral neck in relation to the time interval between injury and surgery and the type of fracture. MATERIAL AND METHODS: The data of patients with intracapsular fractures of the femoral neck surgically treated in the period from 2001 to 2011 were reviewed. Of 1555 patients treated for this fracture, 125 (7%) underwent osteosynthesis. The evaluated group included 115 patients who came for examination at one-year follow-up. There were 59 (52%) women and 56 (48%) men. Dynamic hip screw (DHS) osteosynthesis with an anti-rotation screw was performed in 103 patients and lag-screw osteosynthesis involving three parallel cannulated cancellous screws was employed in 12 patients. The patients were allocated to groups according to the injury-to-surgery interval and to sub-groups on the basis of the Garden classification of femoral fracture stage. RESULTS: In the group of 58 patients treated within 6 h of injury, AVN developed in 10 (17%). When the type of fracture was considered, 4% of the non-displaced fractures and 30% of the displaced fractures developed AVN. The patients with Garden stage I and II (non-displaced) fractures treated within 6 h of injury had a significantly lower risk of AVN development than those with Garden stage III or IV (displaced) fractures. The group treated between 6 and 24 post-injury hours comprised 21 patients, of whom four (19%) had AVN. In non-displaced and displaced fracture sub-groups, 25% of the patients in the former and 16% in the latter had AVN. The stage of displacement had no effect on AVN development. The two groups together (patients treated by 24 h) had a significantly lower AVN incidence than the patients treated after 24 h (p = 0.0025). In this group of 36 patients, 16 had AVN (44%) and the fracture stage made no significant difference (p = 0.6985; nondisplacement sub-group, 41%; displacement sub-group, 55%). CONCLUSIONS: The study showed a significantly lower AVN occurrence in the patients surgically treated within 24 h of injury. In the patients treated within 6 h of injury, AVN incidence was significantly lower in the patients with non-displaced fractures, as compared with those who had displaced fractures. This was not true for the two patient groups treated later (6-24 and later than 24 h) in which the differences between AVN development after non-displaced fractures and that after displaced fractures were similar.

[Kirschner wire transfixation of unstable ankle fractures: indication, surgical technique and outcomes]. / Transfixace nestabilních zlomenin hlezna Kirschnerovými dráty: indikace, technika provedení a výsledky.

PURPOSE OF THE STUDY The aim of the study was to assess treatment outcomes in patients undergoing K-wire transfixation of unstable ankle fractures and compare the results with those of patients in whom it was possible to perform primary one-stage osteosynthesis. MATERIAL AND METHODS Between 2009 and 2012, a total of 358 patients (191 women and 167 men) had surgery for unstable ankle fracture. At 1-year follow-up, their subjective feelings, objective findings and ankle radiographs were evaluated. The fractures were categorised according to the Weber classification. A patient group treated by one-stage osteosynthesis, a group with definitive transfixation and a group of patients in whom temporary transfixation was converted to definitive osteosynthesis were assessed and compared. RESULTS The group treated by one-stage osteosynthesis included 278 patients with an average age of 47 years; the group of 20 patients with definitive transfixation had an average age of 67 years, and the group of 60 patients who had temporary transfixation with subsequent conversion to internal osteosynthesis were 55 years on average. In the group with one-stage osteosynthesis, 223 (80%) ankle fractures on post-injury radiographs were associated with minor joint dislocations and 55 (20%) with major dislocations. On the other hand, the radiographs of the patients treated by temporary transfixation and delayed open reduction with internal fixation showed major dislocations in 38 (63%) and minor dislocations in the rest of the patients (37%); the difference between the two groups was statistically significant (p<0.001). Posterior malleolar fractures were most frequent in the group with temporary transfixation (60%) and least frequent in the group with primary osteosynthesis (44%); also this difference was statistically significant (p=0.032). At one-year follow-up, in the group with one-stage osteosynthesis, 220 patients (79%) had no radiographic signs of posttraumatic ankle osteoarthritis while, in the group with temporary transfixation, no radiographic evidence of ankle osteoarthritis was recorded in 25 (42%) patients. While tibiofibular synostosis was recorded in only few patients (9%) of the group with one-stage osteosynthesis, it showed a high occurrence in the group with temporary transfixation (35%). The patients with one-stage osteosynthesis (188/68%) had a higher proportion of excellent outcomes measured on the Olerund-Molander ankle scoring scale than the other two groups (temporary transfixation, 47%; definitive transfixation,10%); in both cases the difference was significant (p < 0.001 and p = 0.003, respectively). DISCUSSION In this study the morphological and clinical aspects of surgically treated ankle fractures were assessed. The patients with one-stage osteosynthesis were compared with those treated by temporary or definitive transfixation. The majority of patients undergoing temporary transfixation had a fractured posterior margin of the tibia and major ankle joint dislocation, which suggested serious injuries to bone and ligament structures. Generally, the use of only two K-wires inserted through the calcaneus and talus into the distal tibia is recommended. Patients with K-wire transfixation usually require a longer hospital stay because of the serious nature of their injuries. CONCLUSIONS The therapy of choice for unstable ankle fractures is one-stage osteosynthesis. Temporary transfixation is an effective method of primary management when an unstable fracture cannot be treated by definitive osteosynthesis at the early stage due to local or general health conditions of the patient. The temporary transfixation provides good alignment of the ankle joint necessary for successful healing of soft tissues. A higher occurrence of post-traumatic ankle osteoarthritis, ossification and distal tibiotalar synostosis found in the patients treated by temporary transfixation is more related to serious types of ankle fractures the patient had suffered than to the method itself. Key words: unstable ankle fracture, soft tissue condition, indications for transfixation, treatment outcome.

[Intra-articular reinforcement of a partially torn anterior cruciate ligament (ACL) using newly developed UHMWPE biomaterial in combination with Hexalon ACL/PCL screws: ex-vivo mechanical testing of an animal knee model]. / Intraartikulární augmentace parciální ruptury predního zkrízeného vazu (ACL) nove vyvinutým UHMWPE biomateriálem v kombinaci s Hexalon ACL/PCL srouby: ex vivo mechanické testování animálního modelu kolenního kloubu.

PURPOSE OF THE STUDY Recent trends in the experimental surgical management of a partial anterior cruciate ligament (ACL) rupture in animals show repair of an ACL lesion using novel biomaterials both for biomechanical reinforcement of a partially unstable knee and as suitable scaffolds for bone marrow stem cell therapy in a partial ACL tear. The study deals with mechanical testing of the newly developed ultra-high-molecular-weight polyethylene (UHMWPE) biomaterial anchored to bone with Hexalon biodegradable ACL/PCL screws, as a new possibility of intra-articular reinforcement of a partial ACL tear. MATERIAL AND METHODS Two groups of ex vivo pig knee models were prepared and tested as follows: the model of an ACL tear stabilised with UHMWPE biomaterial using a Hexalon ACL/PCL screw (group 1; n = 10) and the model of an ACL tear stabilised with the traditional, and in veterinary medicine used, extracapsular technique involving a monofilament nylon fibre, a clamp and a Securos bone anchor (group 2; n = 11). The models were loaded at a standing angle of 100° and the maximum load (N) and shift (mm) values were recorded. RESULTS In group 1 the average maximal peak force was 167.6 ± 21.7 N and the shift was on average 19.0 ± 4.0 mm. In all 10 specimens, the maximum load made the UHMWPE implant break close to its fixation to the femur but the construct/fixation never failed at the site where the material was anchored to the bone. In group 2, the average maximal peak force was 207.3 ± 49.2 N and the shift was on average 24.1 ± 9.5 mm. The Securos stabilisation failed by pullout of the anchor from the femoral bone in nine out of 11 cases; the monofilament fibre ruptured in two cases. CONCLUSIONS It can be concluded that a UHMWPE substitute used in ex-vivo pig knee models has mechanical properties comparable with clinically used extracapsular Securos stabilisation and, because of its potential to carry stem cells and bioactive substances, it can meet the requirements for an implant appropriate to the unique technique of protecting a partial ACL tear. In addition, it has no critical point of ACL substitute failure at the site of its anchoring to the bone (compared to the previously used PET/PCL substitute). Key words: knee stabilisation, stifle surgery, ultra-high-molecular-weight polyethylene, UHMWPE, nylon monofilament thread, biodegradable screw, bone anchor.

Perioperative cardiovascular complications versus perioperative bleeding in consecutive patients with known cardiac disease undergoing non-cardiac surgery. Focus on antithrombotic medication. The PRAGUE-14 registry.

BACKGROUND: Interruption of antithrombotic treatment before surgery may prevent bleeding, but at the price of increasing cardiovascular complications. This prospective study analysed the impact of antithrombotic therapy interruption on outcomes in non-selected surgical patients with known cardiovascular disease (CVD). METHODS: All 1200 consecutive patients (age 74.2 ± 10.2 years) undergoing major non-cardiac surgery (37.4 % acute, 61.4 % elective) during a period of 2.5 years while having at least one CVD were enrolled. Details on medication, bleeding, cardiovascular complications and cause of death were registered. RESULTS: In-hospital mortality was 3.9 % (versus 0.9 % mortality among 17,740 patients without CVD). Cardiovascular complications occurred in 91 (7.6 %) patients (with 37.4 % case fatality). Perioperative bleeding occurred in 160 (13.3 %) patients and was fatal in 2 (1.2 % case fatality). Multivariate analysis revealed age, preoperative anaemia, history of chronic heart failure, acute surgery and general anaesthesia predictive of cardiovascular complications. For bleeding complications multivariate analysis found warfarin use in the last 3 days, history of hypertension and general anaesthesia as independent predictive factors. Aspirin interruption before surgery was not predictive for either cardiovascular or for bleeding complications. CONCLUSIONS: Perioperative cardiovascular complications in these high-risk elderly all-comer surgical patients with known cardiovascular disease are relatively rare, but once they occur, the case fatality is high. Perioperative bleeding complications are more frequent, but their case fatality is extremely low. Patterns of interruption of chronic aspirin therapy before major non-cardiac surgery are not predictive for perioperative complications (neither cardiovascular, nor bleeding). Simple baseline clinical factors are better predictors of outcomes than antithrombotic drug interruption patterns.

Developmental malformations in the area of the lumbosacral transitional vertebrae and sacrum: differences in gender and left/right distribution.

PURPOSE: The aim of this study was to determine the incidence of congenital malformations of the lumbosacral transitional vertebrae in the general population, and the differences in their gender and left/right distributions. METHODS: The examined group comprised of all patients who underwent a pelvic X-ray during 2010 for any reason. The observed parameters included the following malformations: the presence of megatransversus at L5; sacralization of L5 or L6; a S1 lumbarization; the presence of six sacral vertebrae; or spina bifida at the level of L5, S1 or S2. In cases of megatransversus at L5, the lateral distribution was recorded. A total of 1,513 images were evaluated. Sex and lateral differences were evaluated using the Pearson's (χ (2)) test with a significance level of 5 %. RESULTS AND CONCLUSIONS: A total of 478 malformations were found in 417 patients, which constituted 27.6 % of the entire group. Malformations occurred in 250 women (25.4 % of all women) and 167 men (31.6 % of all men) and the female to male ratio in affected individuals was 1.5:1. The predominance of the occurrence of malformations observed in men was statistically significant (p = 0.009). The most frequently occurring malformations were the presence of six sacral vertebrae (179 patients) and megatransversus at L5 (150 patients). The study confirmed a high incidence of congenital malformations in the area of the lumbosacral transitional vertebrae and demonstrated a higher incidence in males. Unilaterally occurring megatransversus at L5 was significantly more common on the left side.

[Intraoperative CT navigation in spinal and pelvic surgery: initial experience]. / Peroperacní CT navigace u operací pátere a pánve: první zkusenosti.

INTRODUCTION: The authors describe their first experience with virtually navigated pelvic and spine screws based on perioperative CT navigation. MATERIAL AND METHODS: From 22 October 2012 (launching the device) to 9 January 2013, a total of 15 CT-navigated pelvic and spine operations were performed in 14 patients. Nerve root compression, scoliosis, vertebral fracture and spondylodiscitis were the indications for spine procedures; B-type and C-type fractures according to the AO classification were the indications in pelvic surgical procedures. The preparation and the course of the procedures were in accordance with current standards and recommendations in all the cases. Perioperative navigation and subsequent examination of the screw trajectory were performed via O-arm imaging system (Medtronic Navigation, Louisville, Colorado) instead of the standard C-arm fluoroscopy. RESULTS: A total of 73 screws were inserted (60 transpedicular screws into cervical, thoracic and lumbar vertebrae, 9 iliosacral screws into the first sacral vertebra and 4 pubic screws). Only one of the pubic screws (1.4% of all screws) was found malpositioned at the subsequent perioperative examination and was extracted immediately and replaced. Further complications were not observed and none of the procedures had to be converted into a standard fluoroscopy guided operation. CONCLUSION: A short but intensive experience with perioperative CT navigation allows us to state: 1. CT navigation shortens the operating time and minimalizes the risk of screw malposition in multiple screw spine procedures; 2. CT navigation improves the introduction of iliosacral and pubic screws in pelvic fixations; 3. there is virtually no radiation load to the staff using the CT navigation; 4. mastering this technique will allow a wider use of miniinvasive screw insertion in the pelvis and other regions where minimal dislocation will enable miniinvasive internal fixation.

[Pelvic injuries and acetabular fractures: differences in their severity]. / Poranení pánve a zlomeniny acetabula: rozdíly v závaznosti techto poranení

PURPOSE OF THE STUDY: The aim of the study was to assess differences in the number and severity of associated injuries between patients with pelvic injury and those with acetabular fracture. MATERIAL AND METHODS: The patients treated in the period from January 1, 2008, to December 31, 2010, were enrolled. The group comprised 249 patients (130 women and 119 men) with pelvic injuries and 58 patients (14 women and 44 men) with acetabular fractures. In the patients with pelvic injury, the average age was 52 years, 61 in women and 43 in men, in the range of 17 to 91 years. In the patients with acetabular fracture, the average age was 54 years, 59 in women and 53 in men, in the range of 21 to 96 years. The relevant data including age, sex, cause of injury, associated injuries and the overall severity of injury were obtained from the patient database. The results were statistically analysed using Pearson's .2 test at a 5% level of significance. RESULTS: Acetabular fractures were recorded in more men than women and this difference was significantly higher (p = 0.002) than in the patients with pelvic injury in whom similar numbers of men and women were affected. A fall from height was significantly more frequent as a cause of pelvic injury than that of acetabular fracture (p = 0.034). The patients with pelvic injury also had significantly more associated injuries (p = 0.016) and the number of these patients with an Injury Severity Score (ISS) higher than 16 was significantly higher compared with the number of patients with acetabular fractures (p < 0.001). DISCUSSION: Little published information is available on comparison of the severity of injuries in patients with pelvic injuries and those with acetabular fractures because these conditions are in fact two nosological units. In pelvic injuries, as conditions usually accompanied by multiple trauma, associated injuries, risk factors for death, requirements for primary life-saving measures, complications and treatment outcomes have been studied. Less attention has been paid to these issues in patients with acetabular fractures; the authors focused on determining the quality of intra-articular fracture treatment in relation to a subsequent risk of avascular necrosis of the femoral head or early arthritis. CONCLUSIONS: The study comparing the patients with pelvic injury with those having acetabular fracture showed a significantly higher proportion of men in the group with acetabular fractures. A fall from height significantly more often caused a pelvic injury than an acetabular fracture. In traffic accidents, drivers usually suffered acetabular fractures while pedestrians and cyclists had pelvic injuries. However, a significantly higher number of associated injuries and multiple trauma with an ISS > 16 recorded in the patients with pelvic injury in comparison with those with acetabular fractures was the most important difference between these two groups.

[Type AO/ASIF B3 fractures of the thoracic and lumbar spine]. / Poranení hrudní a bederní pátere typu B3 dle AO-ASIF.

PURPOSE OF THE STUDY: Type B3 thoracic and lumbar fractures are often found in spines with previous hyperossification processes such as ankylosing spondylarthritis (AS) or diffuse idiopathic skeletal hyperostosis (DISH). They occur most frequently due to high-energy trauma in a healthy spine and as fall-related domestic injury in a spine affected by hyperossification. Generally, they are less frequent than type B3 cervical spine fractures. In this retrospective study involving two centres, the incidence of these fractures, their characterisation, therapy and complications associated with them were investigated. MATERIAL AND METHODS: Between March 2003 and March 2012, 21 patients with type B3 injuries (Magerl classification) were treated in our centres. The thoracic spine was involved in 14 and the lumbar spine in seven patients. The patients' average age was 61.8 years, with a range of 33 to 87 years. There were three women and 18 men. Six fractures occurred in previously healthy spines, five and 10 were in AS- and DISH-affected spines, respectively. The evaluation included the mechanism of injury, patient's weight and height, neurological findings, type of treatment and its result, outcome after treatment termination, complications and associated diseases and injuries. RESULTS: The mechanism of injury differed between the healthy and disease-affected spines. All five AS patients suffered low-energy fractures while patients with previously healthy spines had high-energy injuries. The DISH patients had both low- and high-energy fractures. Type B3.1.1 fractures were diagnosed in two AS patients and six DISH patients, and in no previously healthy patient. Type B3.1.2 fractures were found in one AS patient, two DISH patients and one previously healthy patient. Type B3.2 fracture occurred in one patient with a previously healthy spine, in two AS and two DISH patients. Type B3.3 fractures were in four patients with previously healthy spines. Neurological deficit was found in five injured patients, four of whom had complete paraplegia (Frankel grade A) which did not improve. One AS patient in whom the spinal fracture was associated with Frankel grade C injury improved to Frankel D after surgery. All patients had an elevated BMI, ranging from 25.1 to 41.9; the average value was 32.2, which is within grade 1 obesity. Associated injuries were found in 11 patients, mostly in those with high-energy trauma. Seventeen patients were treated surgically, four conservatively. Posterior stabilisation was carried out in 10 patients who had either AS or DISH conditions; seven patients had a short spinal stabilisation. Complications included early infection in two patients, cerebrospinal fluid fistula in one, urinary tract infection in one and confused state of mind in two patients. All patients healed well but for one patient who died at 4 months after injury due to multiple complications. DISCUSSION: In the majority of relevant publications these injuries are reported in patients suffering from hyperossification disorders such as AS or DISH. In patients with healthy spines they occur less frequently and the traumatic hyperextension mechanism must have great intensity. Fractures of a hyperossified spine are related to obesity and this was also confirmed by our study in which all patients were overweight or obese. This factor plays an important role in the hyperextension mechanism that produces a sudden overcoming of the resistance of a spinal segment to force, resulting in a type B3 fracture. CONCLUSION: A different approach to these fractures is required in comparison with other spinal fractures. Type B3 fractures have some features common with type C fractures and are frequent in spines affected by spinal disease. In hyperossification disorders, paradoxically associated with advanced osteoporosis, fracture treatment requires long instrumentation. In healthy spines, fractures are treated with short instrumentation. In AS and DISH patients, the diagnosis may be delayed because these patients suffer from chronic spine pain and the pain due to fracture may be attributed to an accelerated chronic condition.