[Surgical Treatment of Degenerative Lumbar Stenosis and Spondylolisthesis: Clinical Practice Guideline]. / Chirurgická lécba degenerativní lumbální stenózy a spondylolistézy: klinický doporucený postup.

PURPOSE OF THE STUDY This article presents the evidence and the rationale for the recommendations for surgical treatment of degenerative lumbar stenosis (DLS) and spondylolisthesis that were recently developed as a part of the Czech Clinical Practice Guideline (CPG) "The Surgical Treatment of the Degenerative Diseases of the Spine". MATERIAL AND METHODS The Guideline was drawn up in line with the Czech National Methodology of the CPG Development, which is based on the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. We used an innovative GRADE-adolopment method that combines adoption and adaptation of the existing guidelines with de novo development of recommendations. In this paper, we present three adapted recommendations on DLS and a recommendation on spondylolisthesis developed de novo by the Czech team. RESULTS Open surgical decompression in DLS patients has been evaluated in three randomized controlled trials (RCTs). A recommendation in favour of decompression was made based on a statistically significant and clinically evident improvement in the Oswestry Disability Index (ODI) and leg pain. Decompression may be recommended for patients with symptoms of DLS in the event of correlation of significant physical limitation and the finding obtained via imaging. The authors of a systematic review of observational studies and one RCT conclude that fusion has a negligible role in the case of a simple DLS. Thus, spondylodesis should only be chosen as an adjunct to decompression in selected DLS patients. Two RCTs compared supervised rehabilitation with home or no exercise, showing no statistically significant difference between the procedures. The guideline group considers the post-surgery physical activity beneficial and suggests supervised rehabilitation in patients who have undergone surgery for DLS for the beneficial effects of exercise in the absence of known adverse effects. Four RCTs were found comparing simple decompression and decompression with fusion in patients with degenerative lumbar spondylolisthesis. None of the outcomes showed clinically significant improvement or deterioration in favour of either intervention. The guideline group concluded that for stable spondylolisthesis the results of both methods are comparable and, when other parameters are considered (balance of benefits and risks, or costs), point in favour of simple decompression. Due to the lack of scientific evidence, no recommendation has been formulated regarding unstable spondylolisthesis. The certainty of the evidence was rated as low for all recommendations. DISCUSSION Despite the unclear definition of stable/unstable slip, the inclusion of apparently unstable cases of DS in stable studies limits the conclusions of the studies. Based on the available literature, however, it can be summarized that in simple degenerative lumbar stenosis and static spondylolisthesis, fusion of the given segment is not justified. However, its use in the case of unstable (dynamic) vertebral slip is undisputable for the time being. CONCLUSIONS The guideline development group suggests decompression in patients with DLS in whom previous conservative treatment did not lead to improvement, spondylodesis only in selected patients, and post-surgical supervised rehabilitation. In patients with degenerative lumbar stenosis and spondylolisthesis with no signs of instability, the guideline development group suggests simple decompression (without fusion). Key words: degenerative lumbar stenosis, degenerative spondylolisthesis, spinal fusion, Clinical Practice Guideline, GRADE, adolopment.

[Thoracolumbar Compression Fractures in Children]. / Kompresivní zlomeniny thorakolumbální pátere u detí.

PURPOSE OF THE STUDY The study aimed to draw up a diagnosis and treatment guidelines for the management of the most common compression fractures of the thoracolumbar spine in children. MATERIAL AND METHODS Between 2015 and 2017, pediatric patients with a thoracolumbar injury aged 0-12 years were followed up in the University Hospital in Motol and the Thomayer University Hospital. The age and gender of the patient, injury etiology, fracture morphology, number of injured vertebrae, functional outcome (VAS and ODI modified for children), and complications were assessed. An X-ray was performed in all patients, in indicated cases also an MRI scan was done, and in more severe cases a CT scan was obtained as well. RESULTS The average vertebral body kyphosis in patients with one injured vertebra was 7.3° (range 1.1°-12.5°). The average vertebral body kyphosis in patients with two injured vertebrae was 5.5° (range 2.1°-12.2°). The average vertebral body kyphosis in patients with more than two injured vertebrae was 3.8° (range 0.2°-11.5°). All patients were treated conservatively in line with the proposed protocol. No complications were observed, no deterioration of the kyphotic shape of the vertebral body was reported, no instability occurred, and no surgical intervention had to be considered. DISCUSSION Pediatric spine injuries are in most cases treated conservatively. Surgical treatment is opted for in 7.5-18% of cases, in dependence on the evaluated group of patients, age of the patients and philosophy of the department concerned. In our group, all patients were treated conservatively. CONCLUSIONS 1. To diagnose F0 fractures, two unenhanced orthogonal view X-rays are indicated, whereas MRI examination is not routinely performed. In F1 fractures, an X-ray is indicated, and an MRI scan is considered based on the age and extent of injury. In F2 and F3 fractures, an X-ray is indicated and subsequently the diagnosis is confirmed by MRI, in F3 fractures also a CT scan is performed. 2. In young children (under 6 years of age), in whom an MRI procedure would require general anaesthesia, MRI is not routinely performed. 3. In F0 fractures, crutches or a brace are not indicated. In F1 fractures, verticalization using crutches or a brace is considered in dependence on the patient's age and extent of injury. In F2 fractures, verticalization using crutches or a brace is indicated. 4. In F3 fractures, surgical treatment is considered, followed by verticalization using crutches or a brace. In case of conservative treatment, the same procedures as in F2 fractures are applied. 5. Long-term bed rest is contraindicated. 6. Duration of spinal load reduction (restriction of sports activities, or verticalization using crutches or a brace) in F1 injuries is 3-6 weeks based on the age of the patient, it increases with the age, with the minimum being 3 weeks. 7. Duration of spinal load reduction (verticalization using crutches or a brace) in F2 and F3 injuries is 6-12 weeks based on the age of the patient, it increases with the age, with the minimum being 6 weeks. Key words: pediatric spine injury, thoracolumbar compression fractures, children trauma treatment.

[Complications in Spine Surgery: Prospective 13-year follow-up of unplanned revision spinal surgeries]. / Komplikace ve spondylochirurgii: prospektivní 13leté sledování neplánovaných revizních operací pátere.

PURPOSE OF THE STUDY Unplanned revision spinal surgeries constitute a complication in the treatment algorithm for the patient, surgeon and the entire treatment team. Any complication leading to an unplanned revision surgery is therefore undesirable. The percentage of complications referred to in publications on this topic focusing on unplanned revision surgeries only varies from 0.7% to 29.8%, with obvious diversity of causes and significant risk factors. The purpose of the submitted paper is to carry out a prospective evaluation of the most serious complications requiring unplanned revision spinal surgeries in the course of 13 years at a single department performing a broad range of spinal surgeries, namely 1300 procedures annually on average. MATERIAL AND METHODS In the period 2006 - 2018, a total of 16872 patients underwent a surgery at our department. During this period, in 556 patients an unplanned revision spinal surgery was performed. In agreement with literature, the patients were categorised by cause for revision: 1/ impaired wound suprafascial (superficial) healing - superficial infection, 2/ impaired wound subfascial (deep) healing - deep infection, 3/ surgical wound hematoma, 4/ deterioration or occurrence of new neurological symptoms, 5/ cerebrospinal fluid leak (liquorrhoea) and 6/ others. The patients operated on for inflammatory diseases of the spine with subsequent infectious complications, primarily treated at another department, and the patients with open spinal injury were excluded from the study. According to these criteria, a cohort of 521 patients was followed up, namely 236 (45.3%) women and 285 (54.7%) men, aged 1 year to 86 years, with the mean age of 55.0 years (median 60 years). Demographic effects, tobacco smoking and comorbidities were followed up in the cohort, together with the effects of surgery, diagnosis, surgical approach and physician. All parameters were statistically evaluated at a p-value below 0.05, including comparison with the control group. RESULTS Of the total number of 16872 operated patients, a group of 521 (3.09%) patients undergoing a revision surgery for complications was analysed in detail. Impaired wound healing - infection (SSI) was found in 199 (1.18%) patients, of whom superficial infection in 124 cases (0.73%) and deep infection in 75 cases (0.44%). Hematoma in a surgical site was detected in 149 (0.88%) patients. In 63 (0.37%) cases, deterioration of the existing neurological finding or occurrence of a new neurological finding were observed, in 68 (0.40%) cases cerebrospinal fluid leak was reported and in 40 (0.24%) cases other complications were identified. As concerns the surgical assistant, the percentage of complications in a board-certified physician is 2.77 (1.14 - 3.29%), in a medical resident it increases to 3.60 (0.00 - 9.38%) (p<0.05). The prevalence of smokers in the group with complications (N=521) was 34.7%. The control group (N=3650) included 30.1% of smokers (p<0.05). The mean age of patients in the group with complications (N=521) was higher, i.e. 55.0 years, with the median age of 60.0 years, than in the primary cohort (N=16872) with the mean age of 49.8 years and the median age of 52.0 years (p<0.05). The mean BMI in the group with complications was (N=521) 27.3, the median BMI was 26.9. In the control group (N=16872), the mean BMI was 27.11, the median BMI was 26.8. In this case the significance (p>0.05) was not confirmed. The complications prevailed strongly in posterior surgical approach, namely in 483 patients (92.7%). As concerns the surgically treated segment, lumber spine dominates with 320 (61.4%) cases. Corticosteroid therapy was used twice as often in women, namely in 13.1% vs. 6.3%. The group of patients with complications (N=521) showed a much higher average length of hospital stay of 12.8 days compared to the average of 4.6 days (N=16872). DISCUSSION In our cohort, the complication rate was 3.09%, of which infections constituted 1.18%, which is in agreement with similarly focused papers. As regards the patient-related factors, in our study the results reported by literature were confirmed with respect to the age, smoking and comorbidities. Moreover, the posterior surgical procedure, lumber spine surgery and presence of a medical resident are essential (p<0.05). No major age difference was observed between women and men (p>0.05). Obesity is one of the key risk factors, especially in infectious complications. In our cohort, a higher BMI did not increase the risk of complications in general (p>0.05). CONCLUSIONS In correlation with current literature, our cohort confirmed a significantly higher risk of complications leading to revision spinal surgery associated with age, smoking, posterior surgical procedure in thoracic or lumber spine, and presence of a medical resident as a surgical assistant. The average length of hospital stay was demonstrably longer in complicated patients, it almost tripled compared to the whole cohort. Contrary to literature, the effect of obesity on the occurrence of complications was not confirmed. Key words: spinal surgery, complications, infection, reoperation, risk factor, hematoma, cerebrospinal fluid leak, screw malposition, smoking, obesity.

[Hemicorporectomy as the Highest Grade of En Bloc Sacrectomy]. / Hemikorporektomie jako nejvyssí stupen en bloc resekce sakra.

Hemicorporectomy or translumbar amputation is an extensive surgical procedure consisting in removing the lower portion of the body. Thakur et al. found a total of 71 hemicorporectomies described in literature before 2017. In the form of a case study we present the case of our patient with terminal pelvic osteomyelitis, in whom hemicorporectomy was subsequently performed, namely from the spine surgery perspective. The man, 19 years old, was exposed to high-voltage electricity and fell down from a height of 4 meters. He suffered an instable comminuted fracture of T10 (AO A3.3.) with paraplegia (Frankel A) and multiple third-degree burns affecting 25% of his total body surface area. Subsequently, the patient underwent a total of 16 surgical procedures performed by medical experts in various specialties (orthopaedic surgery, general surgery, plastic surgery, urology, vascular surgery), but in spite of that the extensive pelvic osteomyelitis has not been successfully managed. At first, urine and stool diversion were performed. After 3 weeks, i.e. 18 months after the injury, the removal of the lower portion of the body was scheduled. The hemicorporectomy was divided into 4 stages. The surgery started by posterior transecting the spine at L4-L5 segment with nerve root and dural sac ligation and treating the bleeding venous plexus in the spinal canal. After turning the patient to the supine position, the second stage of the operation followed, consisting in transecting large vessels and harvesting a musculocutaneous flap from the right thigh. During the third stage of the surgery the separation of the L4-L5 motion segment was completed by the transaction of the anterior longitudinal ligament and m. psoas major, subsequently followed by the amputation of the lower portion of the body. During the last stage of the surgery, the wound was closed by musculocutaneous flap from the fight thigh with preserved a. femoralis. The patient was discharged to home in a generally good condition 127 days after the amputation of the lower portion of the body. Now, 1 year after the surgery, the patient enjoys good physical as well as mental health. Hemicorporectomy is an extensive surgical technique, which can despite multiple complications be offered to patients with otherwise unmanageable condition. Terminal pelvic osteomyelitis is currently the most frequent diagnostic indication and the resulting condition makes possible a long-term survival of the patient in a satisfactory condition. The spinal surgeon is an irreplaceable member of the multidisciplinary team performing the surgical procedure, the primary treatment of the spinal column considerably limits blood losses. Key words: hemicorporectomy, en bloc sacrectomy, terminal pelvic osteomyelitis, sacral tumors.

Tularemia - zoonosis carrying a potential risk of bioterrorism.

Tularemia, otherwise known as “rabbit fever”, is a zoonotic disease caused by a gram-negative intracellular bacterium - Francisella tularensis. The species is considered as a potential bioterrorism agent due to its high infectivity, the fact of being relatively easy to culture, the absence of human vaccine, and the potential for spreading through aerosol. In the Czech Republic, infection is usually caused by a tick bite, less frequently by a mosquito bite, direct contact with infected animals, or ingestion of contaminated water. The aim of this review is to provide a comprehensive view of tularemia, its diagnosis, clinical symptoms and treatment, along with the military perspective on a potential risk of F. tularensis to be misused as a biological weapon.

Anatomy of the dens and its implications for fracture treatment: an anatomical and radiological study.

PURPOSE: The most common injuries to the upper cervical spine are fractures of the dens axis. Therefore, the purpose of our study was to answer three questions, namely (1) whether the size of the dens is adequate at all levels to accommodate two screws, (2) what the angle of the posterior tilt of the dens is in a healthy individual and (3) compare the measured variables between the sexes. METHODS: The cohort comprised 50 males and 50 females CT examination of the craniocervical junction. We measured the five diameters of the dens and posterior dens angulation angle (PDAA) and screw insertion angle (SIA). The same dimensions were measured in a control group, consisting of 40 non-pathological second cervical vertebrae specimens. RESULTS: On CT scans, the mean PDAA was 162.7 degrees in males and 160.26 degrees in females; the mean SIA was 62.0 degrees in males and 60.2 degrees in females. On specimens, the mean PDAA was 169.47 degrees in males and 166.95 degrees in females; the mean SIA was 65.42 degrees in males and 64.47 degrees in females. All obtained values were higher in males; regardless of their measuring on either CT scans or specimens, differences between males and females were statistically significant (p < 0.05) in a, c, d and e values. CONCLUSIONS: The values of our measurements correlate with the dimensions identified previously in other studies. Based on our clinical experience and measurements, we presume that two 3.5-mm screws can be inserted into the dens of all adult patients, except for those with pronounced anatomical anomalies. Posterior dens angulation angle is slightly larger than we expected. The dens is significantly larger in males almost in all measurement. These slides can be retrieved under Electronic Supplementary Material.

[Surgical Therapy of Fixed Atlantoaxial Rotatory Dislocation - Monocentric Study of 15 Patients]. / Chirurgická terapie fixované atlantoaxiální rotacní dislokace ­ monocentrická studie 15 pacientu.

PURPOSE OF THE STUDY Atlantoaxial Rotatory Dislocation (AARD) mostly occurs in children and prevailing majority of cases are successfully managed by non-operative treatment. Surgical intervention is necessary in patients in whom non-operative treatment failed, in case of repeated dislocations and in patients with anatomical defects of the atlantoaxial complex. The purpose of the presented study is the radiological and clinical evaluation of patients with AARD surgically treated at our department. MATERIAL AND METHODS In the period from 2001 to 2017, altogether 15 patients with AARD were surgically treated at our department, namely 6 men and 9 women aged 5-72 years, with the mean age of 27.3 years. 8 patients were younger than 18 years of age. Apart from regular checks, all the patients were examined also at the end of the study, which means at a follow-up of 12-214 months, i.e. 112.1 months postoperatively on average. In the study, the anatomy of the atlantoaxial complex and craniocervical junction, course of the surgical procedure, correction of deformity, bone fusion, clinical condition of the patient and complications were monitored and evaluated. The clinical evaluation was performed using the Visual Analogue Scale (VAS) for neck pain and the Neck Disability Index (NDI). All the parameters were statistically evaluated at the p-level below 0.05. RESULTS In all 15 patients the surgery was preceded by unsuccessful non-operative treatment. The period between the rotation and the surgery was 4 days to 48 months, with the mean value of 11.3 months. All the patients included in the study showed an intact dens axis, the other patients were excluded from the study. In 10 patients their head was rotated to the left, in 5 patients to the right. The anterior atlantodental interval (ADI) was 2-7 mm with the mean value of 3.5 mm. In 13 cases the ADI was less than 5 mm, in 2 cases it was greater. According to the Fielding and Hawkins classification there were 9 cases of type I, 4 cases of type II and two cases of type III. According to the Ishii et al. classification, 2 cases of type I, 12 cases of type II and one case of type III were identified. In 9 patients predisposing factors were found in the history, namely 7 cases of trauma, 2 cases of infection. Mutual rotation of C1-C2 from 7.0° to 60.0° with the mean value of 27.3° was observed preoperatively, while after the correction it was from 1.0° to 7.0° with the mean value of 3.9° (p < 0.05). Lateral inclination was 3.4°-23.6° preoperatively with the mean value of 9.9°, and 0.7°-4.0° after the correction with the mean value of 2.2° (p < 0.05). The postoperative ADI ranged from 1 to 3 mm, with the mean value of 1.9 mm (p < 0.05). The bone fusion of C1-C2 or C1-C2-C3 was achieved in all the relevant cases (N = 13, 100%), in two patients a temporary fixation was used. The mean value of VAS for neck pain was 6.3 preoperatively, 1.0 (p < 0.05) at one year and 1.0 (p < 0.05) again at the final examination. The mean value of NDI was 50.4 % preoperatively, 9.3% (p < 0.05) at one year and 9.5% (p < 0.05) at the final examination. All patients that we operated on stated that they would undergo surgery again. DISCUSSION Compared to the other authors, our group of patients included surprisingly many adult patients (46.7%) with a high percentage of neurological defects (33.3%). In agreement with the literature, the cause of rotation was revealed in 60% of cases. At our department, correction is preferred in all the patients, while especially in paediatric patients in situ fixation causes the developmental deformities of the face and cervical spine. High success rate of bone fusion was confirmed (13/15, 13 = 100%) and also the transient atlantoaxial fixation was successfully used in two patients, both with traumatic etiology. CONCLUSIONS If non-operative treatment fails, surgical correction of AARD is a suitable treatment method which ensures favourable position of the atlantoaxial complex, improves the clinical condition of the patient and prevents the asymmetric development of the face in children. The Goel-Harm's fixation technique and C1-C2 fusion are considered by us the method of choice in older paediatric and adult patients. Key words: AARD, atlantoaxial rotatory dislocation, atlantoaxial rotatory subluxation, pediatric cervical spine, atlantoaxial fixation.

[Surgical Treatment of High-Grade High-Dysplastic Spondylolistheses in Young Patients - Prospective Monocentric Study of 29 Patients]. / Operacní lécba vysokostupnových vysoce dysplastických spondylolistéz u mladých jedincu ­ prospektivní monocentrická studie 29 pacientu.

PURPOSE OF THE STUDY An optimal technique to surgically treat high-grade high-dysplastic (HG HD)spondylolistheses remains disputable. There are multiple surgical procedures described, ranging from a simple posterior fusion in situ without fixation through a standalone anterior lumbar interbody fusion with the oblique insertion of a structural bonegraft to instrumented full reduction and 360-degree fusion. At our department, preference is given to the instrumented monosegmental reduction and fixation by a fixator with Schanz screws. The aim of this paper is a prospective clinical and radiological evaluation of the group of operated patients below 30 years of age with HG HD spondylolisthesis with a slip greater than 50%. MATERIAL AND METHODS In the period from 11/2007 to 2/2017, a total of 29 patients with HG HD spondylolisthesis always of the L5-S1 segment were treated at the Department of Spinal Surgery of the First Faculty of Medicine of the Charles University and the Teaching Hospital Motol. They were 10 men and 19 women aged 10 to 28 years, with the mean age of 18.4 years. In 27 patients reduction and single-segment fixation of L5-S1 were performed as primary treatment, in one case decompression and noninstrumented-fusion only was carried out and in one case in situ fixation of L4-L5-S1 for distinctive osteoporosis. RESULTS The average duration of posterior surgery without the reconstruction of the anterior column was 88.9 min, in case of anterior fusion it was 46.6 min and in case of only posterior approach and fusion with the reconstruction of the anterior column it was 141.5 min. The average blood loss in the posterior fusion without the reconstruction of the anterior column reached 384.3 ml, in the stand-alone anterior fusion it was 21.6 ml. and in the posterior fusion with the reconstruction of the anterior column 430.0 ml. In 27 patients in whom the reduction was carried out, a shift of the L5 vertebral body observed on the CT scan prior to the surgery was 64.3% on average, while postoperatively and also at 6 months after the surgery during the follow-up examination it was 8.1%. A clear bone posterolateral fusion was found by the CT examination after 4-6 months in all 29 patients (100%, N = 29), while bone intersomatic fusion was reported in 25 cases (96.2%, N = 26). Altogether 6.9% of residual neurological deficits were observed. The statistical processing of VAS values for lumbar back pain and ODI values before the surgery and after two years confirmed a significant improvement of the clinical condition (p < 0.001). When asked whether they would undergo the same surgery with their current experience with the treatment, all the 29 patients answered "yes" and stressed the functional as well as the aesthetic results of the surgery. DISCUSSION In agreement with the other authors, the PT, SS and PI values are measured and we consider the SA, SDSG LSA and Dubousset s LSA assessments to be essential. All the measured values showed statistically significant changes postoperatively, only the pelvic incidence(PI) value remained unchanged. In patients with HG HD spondylolisthesis, we prefer reduction and the 360-degree monosegmental fusion, in the case of sacral osteotomy always using the posterior approach, in the cases where osteotomy is not performed using the next anterior approach. Even in the cases of the most severe deformities, we prefer to maintain the body of L5 and, where necessary, rather shorten the sacrum, which in our opinion leads to a better aesthetic result. CONCLUSIONS The reduction by single-segment instrumentation is a suitable alternative to the surgical therapy of HG HD spondylolistheses in young patients. It provides a high success rate of bone fusion and good clinical results including the aesthetic aspects. The complications associated with full reduction are not markedly higher than in other surgical techniques. Key words:spondylolisthesis, HGHD, high-grade, high-dysplastic, reduction, pelvic incidence, pelvic tilt, sacral slope.

[Giant Ganglioneuroma of the Spine and Mediastinum]. / Objemný ganglioneurom pátere a mediastina.

UNLABELLED: The case of a 15-year-old girl with a large ganglioneuroma in the mediastinum and spinal canal is presented. The tumour initially manifested as scoliosis. Its diagnosis was made on the basis of CT scanning and magnetic resonance imaging, and confirmed by thoracoscopic mediastinal biopsy. Radical tumour excision was indicated. The first stage involved removal of the tumour from the spinal canal through a posterior approach, and transpedicular fixation of the spinal column with correction of the curve. At the second-stage procedure, the tumour was removed from the pleural cavity and mediastinum through thoracotomy. At two years after surgery, the spondylodesis was completed with autologous bone grafts that healed within 6 months. At 3-year follow-up the patient was with neither clinical findings, nor subjective complains and imaging methods showed no signs of tumour recurrence. KEY WORDS: ganglioneuroma, scoliosis, correction, thoracotomy, spinal canal, mediastinum.

Identification of novel biomarker candidates for hypertrophic cardiomyopathy and other cardiovascular diseases leading to heart failure.

In-depth proteome discovery analysis represents new strategy in an effort to identify novel reliable specific protein markers for hypertrophic cardiomyopathy and other life threatening cardiovascular diseases. To systematically identify novel protein biomarkers of cardiovascular diseases with high mortality we employed an isobaric tag for relative and absolute quantitation (iTRAQ) proteome technology to make comparative analysis of plasma samples obtained from patients suffering from non-obstructive hypertrophic cardiomyopathy, stable dilated cardiomyopathy, aortic valve stenosis, chronic stable coronary artery disease and stable arterial hypertension. We found 128 plasma proteins whose abundances were uniquely regulated among the analyzed cardiovascular pathologies. 49 of them have not been described yet. Additionally, application of statistical exploratory analyses of the measured protein profiles indicated the relationship in pathophysiology of the examined cardiovascular pathologies.

[Localized Amyloidosis Involving the Nasal Cavity]. / Lozisková amyloidóza v dutine nosní.

BACKGROUND: Amyloidosis is a disease characterized by deposits of abnormal protein known as amyloid in various organs and tissues. It can be classified into systemic or localized forms, the latter of which is less frequent. Deposition of amyloidogenic monoclonal light chains leads to the most common type of this disease called light-chain (AL) amyloidosis. (18)F-FDG positron emission tomography/ computed tomography hybrid imaging (FDG-PET/ CT) demonstrates tracer uptake usually in all patients with localized amyloidosis as opposed to the systemic form. CASE: Herein, we present a case of an otherwise healthy 56-year-old women diagnosed with a nasal polyp on the right side. The biopsy results were consistent with amyloidosis. FDG-PET/ CT imaging revealed a pathological, metabolically active lesion measuring 11 × 9 mm with a maximum standardized uptake value (SUV(max)) of 3.47. No other distant pathological changes were identified. After a radical resection, the patient has been regularly followed-up with clinical and imaging methods (MRI, FDG-PET/ CT), both of which repeatedly showed normal findings with disease-free survival of 27 months. Thus, FDG-PET/ CT imaging plays an important role not only for obtaining the right diagnosis but also in the follow-up of patients after surgical resection. In accordance with the literature, this case report confirms that FDG-PET/ CT imaging holds promise as an auxiliary method for distinguishing between localized and systemic forms of amyloidosis.

Total En Bloc Spondylectomy of C3: A New Surgical Technique and Literature Review.

PURPOSE OF THE STUDY: Radical resection of a vertebra is reserved only for specific tumors that invade the surrounding tissues and recur when not removed completely. The vertebra may be removed using a piecemeal technique or en bloc, using only two (in thoracolumbar spine) or more osteotomies (in cervical spine). We present our technique of en bloc resection of subaxial cervical vertebra for Ewing's sarcoma of C3, with preservation of all nerve roots and both vertebral arteries. To our knowledge, this surgical technique has not been reported in the English literature. The aim of this study is to describe the new technique of radical resection of subaxial cervical vertebra. MATERIAL AND METHODS: A transoral biopsy of tumor tissue anterior to C2-C3 was performed in 8-year old boy, revealing a diagnosis of Ewing's sarcoma. The patient was started on neoadjuvant chemotherapy. After 6 chemotherapy cycles with the VIDE regimen, the soft-tissue component completely regressed, with the only a residual deposit in C3 vertebral body. Based on further multidisciplinary meeting, an en bloc spondylectomy of C3 was recommended, preferably with preservation of nerve roots and vertebral arteries. In August 2014, prior to the planned surgery, we performed another thorough examination of the patient using plain films, CT and MRI. Neither angiography nor embolization was performed. DESCRIPTION OF SURGICAL TECHNIQUE: The first stage of the operation consisted of resection of the posterior structures. We exposed the posterior elements of C2 to C4 by the mid-line incision. The C3 arch was without pathological changes. After partial resection of the C2 inferior and C4 superior articular processes we performed bilateral osteotomy in the region of the pedicle adjacent to the arch with a chisel and removed the whole of the C3 posterior arch. Subsequently we perforated the transverse foramina close to the pedicle, using fine Kerrison rongeurs. The lateral parts around vertebral arteries were left in situ. In the next step we used instrumentation with polyaxial screws to stabilize the C2-C4 section. After 19 days we performed the second stage surgery from an anterior approach with the removal of the anterior and lateral parts of the vertebra. We made a transverse incision anterior to the sternocleidomastoid between the internal carotid artery and the trachea on the right side at the level of C3 to expose the spine. We resected C2-C3 and C3-C4 intervertebral discs and then performed osteotomy with fine Kerrison rongeurs on both sides, again, close to the vertebral body. Subsequently, the vertebral body was released and extracted en bloc. In the next step, both vertebral arteries were mobilized and shifted medially and the lateral portions of the transverse processes were released and removed en bloc. The empty space was filled with solid allograft and the C2-C4 levels were bridged by the cervical plate in 2+1+2 configuration. RESULTS: There were no complications during both surgeries. The follow-up CT examination 4 months after the operation revealed a clear bone fusion of C2-C4, both anteriorly between vertebral bodies and posteriorly between the arches. Clinically the patient has reached 8 month follow up and had no complaints, both he and his parents were satisfied. Physiotherapy is proceeding according to plan. The patient remains under supervision at our centre. DISCUSSION: Total en bloc resection of a subaxial cervical vertebra with preservation of neural and vascular structures has been described in the English literature only once. In 2007 was published a total en bloc resection of C5 for chordoma, preserving the above mentioned structures. Authors removed the lamina en bloc after bilateral osteotomy. Transverse foramina were perforated by the Gigli saw and removed in piecemeal fashion, including the posterior tubercle. In the next step, they removed the vertebral body and the anterior tubercle from the anterior approach. However, their treatment differs from the technique described here and does not correspond fully to the principle of en bloc resection. Our surgical technique is based on a similar principle of performing several osteotomies without the use of high speed burr, while preserving all neural and vascular structures. The difference can be particularly seen in the approach to remove lateral parts of the transverse foramen, which are surrounding the vertebral arteries. We consider it as ideal to split the cervical vertebra by smooth cuts into four parts and remove them en bloc. CONCLUSION: Total en bloc spondylectomy of a subaxial cervical vertebra with preservation of vertebral arteries and nerve roots is a radical surgery that should be used to treat only the most serious conditions. The risk of neurological deficit is outweighed by the benefits of oncological radicality. This new surgical technique has not yet been described and it is clear, that a larger cohort of patients is necessary to assess and potentially modify this technique so that it can be used more frequently in the future.

Stem cells regenerative properties on new rat spinal fusion model.

Stem cells biology is one of the most frequent topic of physiological research of today. Spinal fusion represents common bone biology challenge. It is the indicator of osteoinduction and new bone formation on ectopic model. The purpose of this study was to establish a simple model of spinal fusion based on a rat model including verification of the possible use of titanium microplates with hydroxyapatite scaffold combined with human bone marrow-derived mesenchymal stem cells (MSCs). Spinous processes of two adjacent vertebrae were fixed in 15 Wistar rats. The space between bony vertebral arches and spinous processes was either filled with augmentation material only and covered with a resorbable collagen membrane (Group 1), or filled with augmentation material loaded with 5 × 106 MSCs and covered with a resorbable collagen membrane (Group 2). The rats were sacrificed 8 weeks after the surgery. Histology, histomorphometry and micro-CT were performed. The new model of interspinous fusion was safe, easy, inexpensive, with zero mortality. We did not detect any substantial pathological changes or tumor formation after graft implantation. We observed a nonsignificant effect on the formation of new bone tissue between Group 1 and Group 2. In the group with MSCs (Group 2) we described minor inflamatory response which indicates the imunomodulational and antiinflamatory role of MSCs. In conclusion, this new model proved to be easy to use in small animals like rats.

[Collet-Sicard Syndrome due to Occipital Condyle Fracture. Case Report]. / Colletuv-Sicarduv syndrom pri zlomenine okcipitálního kondylu - kazuistika.

The case of a 63-year-old man diagnosed with Collet-Sicard syndrome due to a fracture of the right occipital condyle is presented. The cause of injury was falling off a bicycle. Dysphonia and dysphagia were present from the moment of injury, with the gradual development of light atrophy of the tongue muscles and right trapezius muscle. The diagnosis was based on examination by CT and MRI methods, the act of swallowing and physical examination by an otorhinolaryngology specialist and a neurologist who confirmed the diagnosis of injury to cranial nerves IX, X and XI on the right side. The patient was treated conservatively with application of a Philadelphia collar. Dysphagia required PEG tube insertion. Skull fracture healing was evident on a CT scan at 3-month follow-up. However, dysphonia with dysphagia and muscle atrophy remained persistent.

[Axial lumbar interbody fusion: prospective monocentric study]. / Axiální lumbální meziobratlová fúze - AxialIF: prospektivní monocentrická studie.

PURPOSE OF THE STUDY: The aim of this prospective study was to evaluate clinical and radiographic results in the patients who underwent L5-S1 fixation using the technique of percutaneous lumbar interbody fusion (AxiaLIF). MATERIAL: The study comprised 23 patients, 11 women and 12 men, who ranged from age of 21 to 63 years, with an average of 48.2 years. In all patients surgical posterior stabilisation involving the L5-S1 segment had previously been done. The initial indications for surgery were L5-S1 spondylolisthesis in 20 and L5-S1 spondylosis and stenosis in three patients. METHODS: The AxiaLIF technique for L5-S1 fixation was indicated in overweight patients and in those after repeated abdominal or retroperitoneal surgery. A suitable position and shape of the sacrum or lumbosacral junction was another criterion. The patients were evaluated between 26 and 56 months (average, 40.4 months) after primary surgery and, on the basis of CT and radiographic findings, bone union and lumbosacral junction stability were assessed. The clinical outcome was investigated using the ODI and VAS systems and the results were statistically analysed by the Wilcoxon test for paired samples with statistical significance set at a level of 0.05. RESULTS: The average VAS value was 6.6 before surgery and, after surgery, 5.2 at three months, 4.2 at six months, 3.1 at one year, 2.9 at two years and 2.1 at three years (n=18). At two post-operative years, improvement in the VAS value by 56.1% was recorded. The average pre-operative ODI value was 25.1; the post-operative values were 17.0 at six months, 12.3 at one year, 10.6 at two years and 8.2 at three years (n=18). At two years after surgery the ODI value improved by 57.8%. To the question concerning their willingness to undergo, with acquired experience, surgery for the same diagnosis, 21 patients (91.3%) gave an affirmative answer. Neither screw breakage nor neurovascular damage or rectal injury was found. CT scans showed complete interbody bone fusion in 22 of the 23 patients (95.6%), In one patient the finding was not clear. Also, posterolateral fusion was achieved in all but one patients (95.6%). A stable L5-S1 segment was found in all patients at all follow-up intervals. The improvement in both VAS and ODI values was statistically significant. DISCUSSION: In addition to indications usual in degenerative disc disease, overweight patients, those who had repeated trans- or retroperitoneal surgery in the L5-S1 region or who underwent long posterior fixation to stabilise the caudal margin of instrumentation are indicated for the AxiaLIF procedure. The clinical results of our study are in agreement with the conclusions of other studies and are similar to the outcomes of surgery using other types of fusion or dynamic stabilisation for this diagnosis. The high rate of fusion in our group is affected by use of a rigid transpedicular fixator together with posterolateral arthrodesis. On the other hand, no negative effects of only synthetic bone applied to interbody space were recorded. CONCLUSIONS: The percutaneous axial pre-sacral approach to the L5-S1 interbody space with application of a double-treaded screw is another option for the management of this much strained segment. The technique is useful particularly when contraindications for conventional surgical procedures are present in patients with anatomical anomalies, in overweight patients or in those who have had repeated surgery in the region. Clinical outcomes and the success rate for L5-S1 bone fusion are comparable with conventional techniques. Complications are rare but their treatment is difficult.

Does sagittal position of the CTDR-related centre of rotation influence functional outcome? Prospective 2-year follow-up analysis.

PURPOSE: Recent studies describe significant rates of heterotopic ossification (HO) after cervical total disc replacement (CTDR). Little is known about the reasons, and one aspect that requires further in vivo investigation is the biomechanical alteration after CTDR and the role of the implant-related centre of rotation (CORi) in particular. The role of the sagittal position of the CORi on functional outcome in two versions of a semi-constrained disc prosthesis with sagittally different CORi is the topic of this study. METHODS: Patients were candidates for single-level CTDR between C3 and C7 who suffered from CDDD and received a standard or flat version of activ C™ (Aesculap AG, Tuttlingen). Clinical and radiographic assessments were determined preoperatively, intraoperatively, at discharge and again at 6 weeks, 6 months, 1 and 2 years. Radiographic examinations were performed independently using specialized quantitative motion analysis software. RESULTS: Clinical outcome improved significantly regarding NDI as well as VAS on neck and arm pain with no differences in mean improvement by study group. Segmental angle measures show a significantly better lordotic alignment for both groups after surgery, but the degree of correction achieved is higher in the flat group. Correlation analysis proves that the more anterior the CORi is positioned, the higher the lordotic correction is achieved (Pearson rho -0.385). Segmental ROM decreased in the standard group but was maintained for flat implants. At present, our data do not demonstrate a correlation between CORi and ROM at 2 years. Two years after surgery, severe HO grade III-IV was present in 31.6 % standard and 13.1 % flat cases with significant differences. Grouping according to HO severity showed comparable sagittal positions of CORi for flat implants but a more posterior position in the severe HO group for standard implants. CONCLUSIONS: Our results confirm the influence of CORi location on segmental alignment, kinematics and HO for a semi-constrained CTDR, but it also indicates a multifactorial process.

[Unstable injuries to the upper cervical spine in children and adolescents]. / Nestabilní poranení horní krcní pátere u detí a adolescentu.

PURPOSE OF THE STUDY: Injuries to the upper cervical spine in children are rare and account for 0.6 to 9.5% of all cervical spine injuries. We present a detailed analysis of the children and adolescents with unstable upper cervical spine injuries treated at our spinal centre. MATERIAL: During 16 years of follow-up, unstable injury to the upper cervical spine was recorded in 23 children and adolescents. Two patients (8.7%) were treated conservatively and 21 (91.3%) underwent surgery. The patients were allocated by age to three groups: 0-9 year, 10-14 year and 15-18 year categories. Twenty patients were seen at the final clinical and radiographic follow-up. One patient died at 62 months after surgery and two patients unfit for transport were evaluated on the basis of mailed interviews. The interval between injury and final evaluation ranged from 6 to 137 months, with an average of 53.4 months. METHODS: The patients treated conservatively first wore a Philadelphia collar, then a custom-made brace, and eventually a soft Schanze cervical collar to finish the healing process. Application of a halo vest was considered a surgical procedure and was used only in very small children. In unstable odontoid fractures, direct osteosynthesis with two cannulated titanium screws was performed from the anterior approach in older children while, in small children, transoral or submandibular retropharyngeal decompression to treat spinal stenosis caused by bone fragments was carried out and a halo vest was applied. Hangman's fractures were treated by anterior cervical discectomy, fusion with bone graft and anterior plate fixation. The other types of unstable fractures were managed from the posterior approach by occipitocervical fixation, atlantoaxial fixation or instrumented fusion extended caudally. The patients characteristics included gender, age, mechanism of injury, type of injury, neurological findings, type of therapy or surgery, complications and treatment outcome. Neurological status was evaluated using the Frankel classification. RESULTS: The patient group comprised 14 boys (60.9%) and nine girls (39.1%), which gave a gender ratio of 3 : 2. The age of patients at injury ranged from 2 to 18 years, with an average of 11 years and 6 months. The most frequent injuries included rotational or vertical atlantoaxial dislocation in eight (34.8%) and odontoid fractures in seven (30.4%) patients; atlas fracture was recorded in three (13.0%) and hangman's fracture also in three (13.0%) patients; occipitocervical displacement was found in one (4.3%) and complex atlantoaxial fracture also in one patient (4.3%). At the time of injury, 17 patients (73.9%) had no neurological deficit (Frankel grade E), three had Frankel grade A (one paraplegic with a concomitant T5 spinal cord injury) and three had Frankel grade D neurological deficits. Of the six patients with neurological deficit, two showed improvement by one or two Frankel grades. The method of dorsal atlantoaxial fixation was used in eight patients (Magerl fixation in 2 and Harms method in 6). Direct osteosynthesis of an odontoid fracture was performed in four patients, halo fixation was applied in four, C2-C3 discectomy with tricortical bone grafting and plating was carried out in three, occipitocervical fixation was used in three patients, and direct atlas osteosynthesis, simple decompression and simple non-instrumented dorsal spondylodesis each was performed in one patient. Neither intra-operative complications nor post-operative complications related to the surgical technique were recorded. Osteoarthritis or bone non-union, as late post-operative complications, were found in two patients. All other patients showed bone healing by first intention in the desired extent. Superficial or deep wound infections were not recorded. DISCUSSION: In the first age category, the number of boys and girls with injuries to the upper cervical spine was equal while, in the third one, the boys outnumbered the girls more than twice. Of the 23 patients, 91.3% were surgically treated; the anterior approach was used in approximately one third of the patients and the posterior approach in the rest of them. The high number of surgical interventions is due to the fact that the most serious paediatric spinal injuries are referred to our centre. CONCLUSIONS: 1. Injuries to the upper cervical spine are most frequently found in the youngest children and in adolescents who, however, frequently have injury also to the lower cervical spine. 2. Neurological deficit is relatively frequent but has a better prognosis than in adults. The youngest children with mild deficits have the best prognosis. 3. The mortality rate in young children with upper cervical spine injuries is evidently high, mostly due to associated head, chest and abdomen trauma 4. Therapy, particularly in small children, is strictly individual.

[Spinal cord concussion: a retrospective study of twenty-four patients]. / Komoce mísní: retrospektivní studie 24 pacientu.

PURPOSE OF THE STUDY: Spinal cord concussion is characterised as fully reversible, temporary inhibition of conductive function due to trauma, without signs of structural changes. Although neurological deficit is usually related to the severity of spinal injury, this is different in spinal cord concussion. The aim of this retrospective study was to evaluate a group of 24 patients with spinal cord concussion, to design a diagnostic algorithm and propose an effective therapy with a good prognosis for the patients. MATERIAL: We reviewed clinical records of 9 768 patients hospitalised at the Department of Spinal Surgery, University Hospital in Motol, from September 2002 till December 2010, and of 457 patients treated at other departments of the Hospital between January 2008 and December 2010; this was a total of 10 225 patients. The data were retrospectively analysed and only the patients with a clear history of trauma and subsequent conservative therapy were selected to comprise a group characterised by the generally known criteria of spinal cord concussion: (1) spinal injury with immediate neurological deficit of varying degree; (2) neurological deficit corresponding to the level of spinal injury; (3) recovery of neurological function within 72 hours of injury; (4) no morphological evidence of injury to the spinal structures obtained by imaging methods. This group comprised 24 patients. METHODS: The patients were followed up from 6 to 95 months, with a mean of 46 months and a median of 48 months, at intervals of 6 and 12 weeks and 6 and 12 months after injury, and then every following year. The recorded information included the patient's age at the time of injury, their gender, the mechanism of injury, reports on alcohol consumption, the first detected neurological deficit, its development immediately after injury, during the hospital stay and at follow-ups in the out-patient department, methylprednisolone administration according to the National Acute Spinal Cord Injury Study (NASCIS) 2, and findings of imaging methods, particularly MRI. RESULTS: Our group consisted of 22 men (91.7%) and two women (8.3%), with an average age of 29 years; the average age was 30 years in men and 18.5 years in women. Seven patients (29.2%) were younger than 18 years, with an average of 16.14 years; the remaining 17 patients (70.8%) were older than 18 years, with an average of 34.35 years. The major mechanisms of injury included falls from a height in 10 patients (41.7%) and injury due to alcohol consumption in five patients (20.1%). Clinical findings involved lesions of the medullary cone in 12 (50.0%), cervical spinal cord in seven (29.2%) and thoracic spinal cord in five (20.8%) patients. Motor function deficit was present in all patients, of whom 10 (41.2%) showed a complete loss of motor function. Impaired sensory function was found in 21 (87.5%) patients. One patient had perianal and genital sensory deficit and one (4.2%) had urinary retention. Neither radiograms nor CT scans showed traumatic changes in any of the patients; MRI findings free of any traumatic spinal changes were recorded in 21 patients (87.5%). One patient had oedema of the T5 and T8 vertebral bodies. No complications were recorded. All patients experienced rapid resolution of neurological deficit, which occurred within 6 hours of injury in two (8.4%), within 12 hours in two (8.4%), within 24 hours in 12 (50.0%) and within 48 hours in six (25.0%) patients, and later than 48 hours after injury in two patients (8.4%). However, recovery always occurred within 72 hours of injury. DISCUSSION: A good prognosis for patients with this injury is supported by our findings, because all patients experienced rapid resolution of neurological deficit within 72 hours of injury. This result is in agreement with the relevant international studies reporting no serious complications associated with spinal trauma. There are no clear recommendations for administration of high doses of methylprednisolone according to the NASCIS system. CONCLUSIONS: Spinal cord concussion is not a frequent injury; in our study, it accounted for 3.54% of the patients with trauma histories out of the total number of 678 patients, or for 2.40% out of 997 injured spinal levels. The first steps should be the same as in any other injury to the spinal cord. An early examination of the patient with imaging methods including MRI is of primary importance. At present administration of methylprednisolone according to the NASCIS system is disputable. The patient diagnosed with spinal cord concussion has a good prognosis, with rehabilitation as the main therapeutic approach.

[Metatropic dysplasia as the cause of atlantoaxial instability, spinal stenosis and myelopathy: case report and literature review]. / Metatropická dysplazie jako prícina atlantoaxiální nestability, stenózy páterního kanálu a myelopatie. Kazuistika a prehled literatury.

We present the case of a patient, aged 4 years and 10 months, with metatropic dysplasia. The baby had repeated apnoeic episodes, bradycardia and cardiac arrests and was diagnosed with foramen magnum stenosis and atlantodental dislocation. The episodes were markedly associated with neck movements. Considering this clinical presentation, we performed laminectomy of the atlas, foramen magnum enlargement and decompression followed by dorsal C0-C2 stabilisa - tion with allogeneic bone chips. After the operation, apnoeic episodes did not recur.

[Surgical treatment for atlantoaxial osteoarthritis (AAOA): a prospective study of twenty-seven patients]. / Operacní lécba atlantoaxiální artrózy (AAOA): prospektivní studie 27 pacientu

PURPOSE OF THE STUDY: Atlantoaxial osteoarthritis (AAOA) is a clinical syndrome with signs distinctly different from those of degenerative sub - axial spine disease. Its diagnosis may long be delayed, partly because of insufficient knowledge and partly due to difficulties in interpreting both anteroposterior and lateral radiographs. The aim of this prospective study was to evaluate the first 27 AAOA patients treated at our department. MATERIAL: From 2001 we performed atlantoaxial fixation with fusion in a total of 29 patients with painful arthritis of the atlanto axial complex. The 27 patients treated before the end of 2010 were enrolled in the study and analysed in detail. This group included 13 women and 14 men aged between 35 and 72 years, with an average age of 53.5 years. In all patients atlanto - axial fixation was performed using the polyaxial screw-rod system according to Harms. METHODS: The patients were followed up at 6 and 12 weeks, 6 and 12 months and then once a year after surgery. X-ray examinations were done at the same intervals as clinical examinations; functional radiographs were made at 12 to 14 weeks after surgery. The definitive analysis of the group was made in the range of 4 to 59 months (average, 25.7 months) after the primary operation. Patients' subjective evaluation was based on NPDI and VAS scores and a question of whether the patient would undergo the surgery again. Objective evaluation included clinical outcomes - pain and neurological findings; radiographic results - stability and healing of C1-C2 fusion; and complications during surgery and in early and late postoperative periods. As intra-operative complications were regarded those associated with the surgical approach, nerve injury and vertebral artery injury. Early post-operative complications included poor wound healing and changes in the patient's neurological status, late complications included instrumentation failure and infection. Patients' clinical status (NPDI, VAS) was statistically evaluated using the one-way ANOVA. RESULTS: The mean VAS score was pre-operatively 7.0 and post-operatively 5.6 at 3 months, 5.0 at 6 months, 5.1 at 1 year; 3.9 at 2 years and 4.0 at 3 years. The mean NPDI value was pre-operatively 39.6 and post-operatively 38.7 at 3 months, 36.0 at 6 months, 34.5 at 1 year, 34.3 at 2 years and 33.1 at 3 years. The question of willingness to undergo the same operation again was answered in the affirmative by 21 patients (77.8%), in the negative by five (18.5%) and one patient did not know (3.7%). Complete bone fusion, as assessed by radiography or CT scanning, was achieved in 26 out of 27 patients (96.3%). In one patient the result was ambiguous but, at 3 months as well as the next follow-ups, C1-C2 complex stability was found. DISCUSSION: All patients in our group underwent a unified system of clinical, radiological, CT and MRI examination. In the decision-making process, emphasis was placed on a correlation of clinical findings with CT scanning results. All patients were operated on from the posterior approach using the Harms method, and radiological outcomes were similar to those of Grob et al. who used the Magerl's technique of C1-C2 fixation. The VAS and NPDI scores demonstrated significant improvement as early as 3 post-operative months, with still further improvement in the following period. The stable clinical status of the patients was achieved at 2 years after surgery. From the practical standpoint we were interested in an answer to the question of whether the patients would be willing to undergo the procedure again. Almost 80% of affirmative answers testified to the correct choice of treatment. The values found corresponded to those reported by Grob at al. CONCLUSIONS: Patients with painful osteoarthritis refractory to conservative treatment will benefit from atlantoaxial fixation and fusion. For the patient, restricted cervical rotation is acceptable in return for pain relief. From the surgical point of view, the risk of complications associated with the operative technique did not exceed a tolerable rate.