[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.

[Our Experience with ICON Hip Resurfacing System]. / Nase zkusenosti s povrchovou náhradou kycelního kloubu ICON.

PURPOSE OF THE STUDY Our study aimed to assess the mid-term outcomes and complications with the ICON hip resurfacing system and to carry out a detailed analysis of pitfalls and risks associated with pairing the bearing surfaces of metal-on-metal hip implants. MATERIAL AND METHODS A total of 52 hip joints were assessed in 43 patients who received the ICON hip resurfacing system at our department between 2009 and 2013. The cohort included 34 men and 9 women. Their age at the time of primary surgery ranged from 34 to 67 years, with the mean age of 51.8 years. The mean follow-up was 7.6 years. The evaluation focused on the position and osseointegration of both components, bone remodelling around the implant, and signs of potential aseptic loosening. The functional status of the hip was assessed by Harris Hip Score. RESULTS The primary stability of both components was always good, there were no femoral neck fractures reported in our cohort. All the acetabular components were stable, showing appropriate osseointegration, with no radiolucent zones or signs of osteolysis around them. There was not a single case of the femoral component stem being in a biomechanically disadvantageous varus position. In zone I and III according to Beaulé, cancellous bone osteolysis developed in two patients. The narrowing of the femoral neck below the end of the femoral component, compared to postoperative X-rays, achieved the mean value of 1.3% according to Grammatopolouse. The HHS increased from 64 to 95.5 points. An excellent outcome was observed in 48 joints, whereas the outcome of the remaining 4 joints was very good. The mean survival rate of the resurfacing hip implant calculated using the Kaplan-Meier analysis achieved 100%. The cobalt and chromium levels in the blood of patients did not exceed the reference physiological value. DISCUSSION The resurfacing system enables to preserve the bone tissue of the metaphysis and a part of the femoral head. The reduced mechanical endurance of the peripheral part of femoral components smaller in size caused by implant malposition resulted in fatal consequences in the ASR system. Greater range of motion conditioned by the design of the resurfacing system led to a mechanical wear, with a significant increase in the concentration of metal particles in the effective joint space. The elevated levels of cobalt and chromium ions in some patients induced delayed-type hypersensitivity with subsequent development of aseptic lymphocyte-dominated vasculitis associated lesions presented as peri-acetabular changes (pseudotumors to osteolysis) with subsequent failure of implant fixation. We have not observed this complication in the ICON system as yet. In patients suffering from hip pain after the resurfacing hip arthroplasty and simultaneous high chromium and cobalt blood levels, pelvic CT/MRI is indicated with reduction of artefacts around the metal material. Surgical treatment of soft tissue affections, bone defects and reimplantation using conventional or revisioncementless components is a possible treatment option. CONCLUSIONS The ideal patient indicated for hip resurfacing is a physically active man under 60 years of age (with a femoral head size of 54-60 mm), with primary or secondary osteoarthritis, no joint deformity, with a good quality bone tissue in the femoral neck and head region. As for the functional performance, the resurfacing system allows the patients a large range of motion with very good joint stability immediately after surgery. Despite that, the metal-on-metal tribological pairing must be approached with caution. The risk of developing lesions associated with ALVAL is unpredictable. In our cohort of patients with ICON hip resurfacing system, mostly excellent outcomes with minimum complications were reported provided the indication criteria and the correct surgical procedure had been complied with. Key words: hip resurfacing system, metal articulating surfaces, adverse reaction to metal particles, aseptic lymphocytedominated vasculitis associated lesions, pseudotumor.

[Assessment of Clinical Outcomes of Surgically Treated Rockwood Type III Acromioclavicular Dislocation with or without Coracoclavicular Ligament Suture]. / Zhodnocení klinických výsledku operacne resených akromioklavikulárních luxací typu Rockwood III se suturou ci bez sutury korakoklavikulárního vazu.

PURPOSE OF THE STUDY Acromioclavicular (AC) joint dislocation and its surgical treatment still raises a number of questions that remain to be answered. In some types of dislocations, Rockwood type III in particular, the indication for surgical treatment as such is relative. There are numerous techniques and implants available for the reconstruction of AC joint. In our research we focused on the necessity of coracoclavicular (CC) joint reconstruction. MATERIAL AND METHODS In this paper, a cohort of 56 patients with Rockwood type III AC joint injury who underwent surgical treatment at our department in 2010-2016 period was retrospectively evaluated. The patients were treated with open reduction with AC joint stabilisation using hook plate or tension band. The patients were divided into 2 groups, namely group 1 with CC ligament reconstruction and group 2 without CC ligament reconstruction. The assessment was done at 6 months, 1 year and 2 years after surgery. The clinical outcomes were assessed based on the absolute Constant score (CS) and coracoclavicular distance (CCD) on the X-ray. Subsequently, the outcomes were statistically processed and compared using the Student s ttest. RESULTS The least invasive surgical intervention, as to the length of incision, was the reconstruction using the hook plate without CC ligament suture, whereas the longest incision was performed in tension band with CC ligament suture. In the CC ligament suture group, the mean operative time was 10 minutes longer. When evaluating the CS of the compared groups with and without CC ligament reconstruction, no statistically significant difference (p > 0.05) was found between the two groups. Similarly, the CCD values at 2-year follow-up did not show any statistically significant difference between the two groups (p > 0.05). CONCLUSIONS The available outcomes suggest that the surgical methods used by us are adequately safe and reliable. Good clinical outcomes can be achieved by open reduction and fixation of Rockwood type III AC joint dislocation even without CC ligament reconstruction. Key words: acromioclavicular dislocation, classification, reconstruction, coracoclavicular ligament.

[Concentration of Hyaluronic Acid in Synovial Fluid as an Indicator of Severity and Degree of Impairment in Patients Suffering from Gonarthrosis]. / Koncentrace kyseliny hyaluronové v synoviální tekutine jako ukazatel závaznosti a stupne postizení u pacientu s gonartrózou.

PURPOSE OF THE STUDY Hyaluronic acid is a major component of synovial fluid and an indicator of joint viscosity and viscoelasticity. Decreased concentrations of hyaluronic acid in the synovial fluid indicate the severity of osteoarthritis. The aim of the study was to determine the concentrations of hyaluronic acid in the synovial fluid and to evaluate the correlation with the severity of osteoarthritis determined based on the radiological criteria (evaluation according to X-ray classification) and the physicochemical criteria (measurement of synovial fluid osmolality). MATERIAL AND METHODS A total of 67 patients with the mean age of 67 years (35 men, mean age = 65 years, and 32 women, mean age = 68 years) with clinically diagnosed osteoarthritis were included in the study. The patients were divided into four groups according to the severity of arthrosis (from Group 1 - the lowest degree of disability to Group 4 - the most severe degree of arthrosis). Samples were taken during knee arthroscopies or total knee replacements. Hyaluronic acid concentrations in synovial fluid were determined using a commercially available kit based on the sandwich ELISA principle (Teco Hyaluronic acid, Switzerland). Osmolality was measured by the cryoscopic method. RESULTS The average concentrations of hyaluronic acid in the synovial fluid in the individual groups were as follows: Group 1: HA = 2302 mg/L, Group 2: HA = 2234 mg/L, Group 3: HA = 2300 mg/L, Group 4: HA = 2446 mg/L. HA concentrations in synovial fluid did not differ from the published reference values in synovial fluid (1500 - 3200 mg/L. HA concentrations do not depend on age, sex, and severity of the disease. The patients who underwent arthroscopy have significantly elevated synovial HA concentration compared to the patients who underwent total knee replacements (2581 mg/l/L vs. 1763 mg/l/L, p = 0.01, Mann-Whitney test). HA positively correlates with the osmotic pressure determined by the examination of osmolality in synovial fluid (r = 0.29, p = 0.015). CONCLUSIONS Hyaluronic acid concentrations in patients with knee osteoarthritis who underwent arthroscopy are significantly increased compared to the group of patients with total knee replacement. Hyaluronic acid concentrations in the synovial fluid correlate with the increased osmotic pressure, and may therefore be an additional indicator of the severity of the disease. Key words: hyaluronic acid, knee arthrosis, total knee replacement, osmolality.

[Revision ACL Reconstruction in Our Study Population]. / Reoperace plastik LCA v nasem souboru.

INTRODUCTION The authors present the long-term clinical outcomes of revision anterior cruciate ligament (ACL) reconstruction. The aim was to compare the surgical technique with respect to the clinical outcomes within 3 years postoperatively. MATERIAL AND METHODS The clinical evaluation of revision anterior cruciate ligament reconstructions performed at our department in 2002-2017 was carried out. A total of 82 patients were included in the study, male as well as female patients. Apart from the clinical outcomes, the associated procedures performed as a consequence of other injuries or damage to other intraarticular structures, the surgical technique as such, potential complications of revision reconstruction and causes of failure were studied. The same criteria were followed up in all the patients - clinical range of motion (ROM) of the operated knee, knee stability - pivot shift test, instrumental Lachman test using Rolimeter, IKDC subjective form, Tegner and Lysholm scores. RESULTS In the group of patients, the surgical technique involved the use of a harmstring tendon autograft as a new graft for revision in 43 patients, a BTB autograft in 25 patients, and a BTB cadaverous graft in 14 patients. In 24 cases, a two-stage surgery was performed. The interval between the first- and the second-stage procedure ranged from 6 weeks up to 6 months, with the median of 62.4 days. During the evaluation, no difference was observed whether one-stage or two-stage surgery was performed, therefore this is not reflected in the overall evaluation. The clinical evaluation resulted in the following mean values when comparing the preoperative and final postoperative findings: The mean value of the IKDC subjective knee form score was 42 (30-62) preoperatively and increased to 77 (66-89) at 3 months. The values obtained at 6 months, 1 year and 3 years were 84 (73-93), 88 (79-100) and 89 (78-100), respectively. The mean value of the Lysholm score in the followedup study population was 63 preoperatively, which indicates a clearly poor result. The score rose to 71 (62-88) at 3 months, to 79 (67-92) at 6 months, to 89 (67-94) at 1 year, and at 3 years the mean score was again 89 (66-95). No serious complications were reported. CONCLUSIONS The results confirmed sufficient postoperative stability of the knee joint. In terms of function and pain perception the treatment was considered appropriate. No major complications occurred during surgeries. Based on the results, the authors foresee the patient s return to sports, at least at recreational level. Key words: anterior cruciate ligament, reconstruction, revision reconstruction, knee arthroscopy, instrumentarium.

Surgical treatment of fractures of the distal radius - ORIF vs external fixation with ligamentotaxis.

INTRODUCTION: The study compares the results of open reduction using volar locking plates with ligamentotaxis by external fixation in fractures of distal radius type 2R3C according to AO classification. METHODS: A retrospective study evaluating the results of osteosynthesis in patients with distal radius fractures type 2R3C according to AO classification, operated until December 2018. The ORIF method with volar locking plates (LCP) was used in 54 patients, and closed reduction with ligamentotaxis using external fixation (EF) was used in 33 patients. The mean age of the patients was 46.7 years in the LCP group and 59.6 years in the EF group. All were evaluated for their X-ray and functional outcomes and according to the Green and OBrien score at 6 and 12 months after surgery.  Results: According to X-rays at 12 months in the LCP group, the mean sagittal tilt was 10.13°, the mean radial inclination was 23.89°, and the mean radial length was 11.84 mm. In the EF group, the mean sagittal tilt was 6.32°, the mean radial inclination was 24.78°, and the mean radial length was 9.89 mm. According to the Green and OBrien score, we recorded a mean score of 84.44 points in the LCP group at 12 month; we achieved good and excellent results in 83.33% of the patients and no poor result was observed. In the EF group the final mean score was 77.27; good and excellent results were achieved in 45.46% of the patients and a poor result in one patient. CONCLUSION: Based on the results in our group of patients, the internal type osteosynthesis using LCP implants can be recommended as a first-choice technique in the treatment of 2R3C fractures according to AO classification.

[Our Experience with RM Pressfit Vitamys Cup and Cementless Optimys Short Stem]. / Nase zkusenosti s jamkou RM Pressfit Vitamys a s krátkým necementovaným dríkem Optimys.

INTRODUCTION The purpose of our study was to evaluate the clinical outcomes in patients at 3-6 years follow-up after primary implantation of RM Pressfit Vitamys cementless elastic cup and cementless Optimys short stem, including bone tissue remodelling around both the components. MATERIAL AND METHODS The evaluation covered 49 joint replacements in patients who had undergone surgery at our department between 2012 and 2015. The age at the time of primary surgery ranged from 29 to 71 years, with the mean value of 59.2 years. Postoperatively, the position of endoprosthesis, changes in femoroacetabular offset, signs of osseointegration of the implant, bone tissue remodelling around both the components and potential signs of aseptic loosening were assessed. The functional status of the joint was evaluated according to the Harris scale. RESULTS The mean follow-up time of Vitamys cup and Optimys stem was 5.6 years and 4.6 years, respectively. We focused on the combination of RM Pressfit Vitamys (49x), Optimys (28x) and Bionit 2 (41x) implants. All the cups showed good osseointegration. Based on the comparisons with a postoperative X-ray, at least mild osteoporosis in the acetabular roof was confirmed in 6 cases. All Optimys femoral components were in direct contact with the Adams arch and with the endosteal side of lateral cortex of proximal femoral metadiaphysis. Femoroacetabular offset was slightly decreased in 5 patients only. The final evaluation in 2018 did not confirm any radiolucent lines or signs osteolysis around any of the components. In 2 stems only, distal migration less than 2 mm was obvious, with subsequent good osseointegration. Signs of stress shielding were present in 2 femoral components in the form of mild cortical atrophy in the region of the Adams arch. Distal femoral cortical hypertrophy was not observed, the greater trochanter did not show the loss of bone tissue in any of the patients. There were no signs of polyethylene wear. The mean value of HHS increased from 53 to 97 points. An excellent result was achieved in 44 total hip replacements, of which 100 points in 28 cases. In the remaining 5 patients the result was good. The survival rate of both the components was 100% according to the Kaplan-Meier analysis. DISCUSSION The successful functioning of cementless total hip arthroplasty is the correct placement of both components with good primary fixation. Excessive proximal and lateral shift of the centre of rotation results in increased load of endoprosthesis and risk of earlier aseptic loosening, its reduction leads to the weakening of pelvitrochanteric muscles. The shift of the centre of rotation from the original anatomical position should therefore not exceed 5 millimetres. Insufficient cup fixation always results in mechanical failure of an endoprosthesis. Distal migration of stems without contact with external femoral cortex with full weight-bearing of the operated lower extremity in the postoperative period does not constitute a sign of instability, but only its placement enables good osseointegration. Bone remodelling can be assessed by imaging techniques at 2 years after the primary implantation at the earliest. At places with lower load, the bone loss occurs and the loss of bone trabeculae can lead to the failure of fixation of the component. At places with load accumulation, the bone hypertrophy occurs that can be manifested by thigh pain. In case of cementless press-fit cup, the degree of bone remodelling depends on its elasticity, in case of stem on the used material, shape and fixation site. CONCLUSIONS The RM Pressfit Vitamys monobloc cup through its mechanical properties approximates the best the elasticity of bone tissue. The stress distribution around the implant is more symmetrical as against other conventional cementless cups. The Optimys stem enables the reconstruction of anatomical conditions corresponding a healthy hip joint. Respecting the rule of at least three-point fixation is a precondition for good and fast secondary stability of components. Minimising the wear of articulating surfaces and physiological remodelling of adjacent bone tissue are the main factors that help prolong the survivorship of both the components, while also securing more favourable conditions and better outcomes in case of necessity of reimplantation. Key words: cementless elastic cup, short cementless stem, femoroacetabular offset, stress shielding, osseointegration of the implant.

[New Anterior Cruciate Ligament Reconstrucion Using Harmstring Tendon Grafts - Clinical Part]. / Nová metoda rekonstrukce predního zkrízeného vazu kolenního kloubu pomocí hamstringu ­ klinická cást.

PURPOSE OF THE STUDY The authors present the clinical use of the new instrumentation set for the anterior cruciate ligament (ACL) reconstruction using the hamstring tendons (HS). The positionning of the femoral tunnel and the fixation of the graft play an important role for the results of the surgery. The aim of the study was to confirm the proposed surgical technique and the methods of the graft fixation, especially from the point of view of the clinical midterm results at the evaluation up to eight years after the surgery. MATERIAL AND METHODS The clinical evaluation comprises 58 patients operated from 2007 to 2014 using the new instrumentation set. There were 9 men and 49 women included in the sample. The mean age was 34.6 years (range 18 - 58 yrs), namely 36.7 in women and 32.4 years in men. The evaluation was performed pre-opeatively and at 3 and 6 months, 1, 3, 5 and 8 years post-operatively. All the patients were followed based on the same criteria - clinical range of motion (ROM), stability of the knee - instrumentation Lachman test utilizing Rolimeter, subjective IKDC score and pain VAS scale for the harvesting site. The ocurrence and the rate of post-operative complications were monitored. RESULTS The integration and the ingrowth of the graft were achieved in all cases, the full ROM was gained as well, no pathological instability was observed. The fixation of the HS graft in the bone was confirmed by post-op X ray at 3 months after the surgery. The clinical evaluation showed the following mean differences in the pre-op and final post-op findings. The average preoperative laxity using the Lachmann test was 9.7 mm (range 6-12 mm), at 3 months 1.8 mm (1.4-2.1 mm), at 6 months 1.6 mm (1.2 - 2.2 mm), at 1 year 1.6 mm (1.1-2.3 mm), at 3 years the stability was 1.7 mm (1.2 mm-2.4 mm), at 5 years 2.3 mm (1.2-3.6 mm) and at 8 years after surgery it was 2.5 mm (1.2-3.9 mm). None of the patitents included in the study showed pathological instability that would be considered an indication for revision. In the evaluation of the subjective IKDC score, the pre-operative average was 56, with the range of 42-66, at 3 months post-operatively 79 (69-85), at 6 months 88 (74-92), at 1 year 95 (88-100), at 3 years 96 (89-100), at 5 years 94 (87-100), and at 8 years 92 (84-98). No severe complications were observed. CONCLUSIONS The method provided sufficient post-operative stability of the knee joint. Fixation of the femoral screw satisfied the demands laid on it. Regarding the pain perception, the method was considered positive, the level of pain involved in the procedure was low. No severe complications or technical mistakes occurred during the surgical procedures. The new instrumentation set developed for the ACL reconstruction offers an easy technique and comfortof use. Key words:anterior cruciate ligament, reconstruction, hamstrings, knee arthroscopy, instrumentation set.

[New Technique of Anterior Cruciate Ligament Reconstruction Using Hamstrings - the Surgical Instrumentation Set]. / Nová metoda rekonstrukce predního zkrízeného vazu kolenního kloubu pomocí hamstringu ­ operacní instrumentárium.

PURPOSE OF THE STUDY The success rate of the anterior cruciate ligament (ACL) reconstruction depends on the fixation of the graft, the surgical technique and, of course, on the experience of the operating surgeon. The authors present the development of the construction of the new instrumentation set designed to manage the ACL lesions using the hamstring (HS) tendons. The study is divided into two parts, of which part one focuses on construction, methods and work with new instruments, while part two presents the outcomes of the surgery. MATERIAL AND METHODS Fixation of hamstring grafts depends, contrary to the union of bone blocks in the Bone-Tendon-Bone (BTB) graft and the bone tunnel, on the method of tendon graft fixation and compression inside the bone tunnel. The instrumentation set for ACL reconstruction is designed to be used for hamstring tendons (semitendon and gracilis) forming four strands of the prepared graft. The system was designed as the fixation of the graft using the femoral screw with eyelet and a press-fit fixation using a metal interference screw in tibia. The easiest and fastest option has proven to be the pulling of the screw with eyelet through the tibial tunnel and intra-articular space to the femoral canal, where fixation by screwing in is done. The exact position of the inserted screw is verified by the measuring gauge. The screw is pulled in by the long version of the femoral screwdriver and Kirschner wire passing through the middle of the screw with eyelet. The advantage of this system consists in the subsequent insertion of the interference screw by the same wire, which guarantees its exact positioning in the centre between the individual strands of the graft (thanks to the specific way of ligament preparation). The possibility of later tensioning of the graft by tightening the femoral screw is another advantage. DISCUSSION Compared to other methods using the HS tendons, the advantages of the described operative technique consist in the simplicity of the used instrumentation procedure. The technique of graft fixation inside the femoral canal is not suitable for bioabsorbable materials. It is offset by the fixation stability and the possibility of final graft tensioning. CONCLUSIONS The newly developed instrumentation set for ACL reconstruction is fit for purpose, easy as to the surgical technique, and it guarantees the logical sequence of surgical steps reducing surgical errors to minimum. The instrumentation set is userfriendly, easy to handle and, once the operating surgeon masters the surgical procedure, it allows to reduce the duration of the surgery to approximately 30 minutes. There were no major complications or technical errors reported during the surgical procedures using these instrumentation set. Key words: anterior cruciate ligament - reconstruction - instrumentation set - knee arthroscopy.

[Mid-Term to Long-Term Results of Revision Total Hip Arthroplasty Using the Oval-Shaped Acetabular Cup - TC Type]. / Strednedobé az dlouhodobé výsledky reimplantací totální náhrady kycelního kloubu pri pouzití oválné revizní jamky ­ typ TC.

INTRODUCTION The purpose of our paper is to evaluate the mid-term to long-term results and to confirm the basic criteria of a high-quality revision implant: safe bridging of bone defects, achievement of reliable primary fixation of revision acetabular cup, achievement of good secondary stability with documentable osteointegration of cup and demonstration of remodelling of transplanted bone tissue in the area of defects and in spaces between the implant ribs. MATERIAL AND METHODS Altogether 36 patients (38 cups) were evaluated who had undergone revision hip arthroplasty in the period from 2004 to 2010. The mean follow-up was 8.2 years (5.1-11.6 years after the reimplantation, more than 10 years in 16 patients who underwent surgery). The position and osseointegration of the implant were assessed by digital radiography, the remodelling of transplanted bone tissues in the area of defects and between the implant ribs by computed tomography with reducing artefacts around the metal implant (Aquilion 64 - Toshiba Medical Systems), and for the clinical outcomes the Harris Hip Score was used. RESULTS Preoperatively, the condition of the hip joint based on the Harris Hip Score was in 30 cases evaluated as poor, in 8 patients as satisfactory. At the time of final evaluation, 8 patients achieved excellent results, in 19 patients the condition of the joint was very good (in 2 patients bilaterally), in 6 patients it was considered satisfactory and in 3 patients poor. The mean value for HHS increased from 39.5 to 84.5. Based on the radiography evaluation, in 27 patients (in 2 patients bilaterally) the osseointegration of the revision cup was good, in 8 cases with a radiolucent line of 2-4 mm in width in DeLee zone III, in one case proximal migration of the cup occurred caused by deep infection. The informed consent form for pelvic CT was signed by 25 patients of our cohort. Remodelling of bone tissue in the space between the ribs of the implant was always detected, the presence of bone cysts was not reported, the bone defects following the application of autologous spongioplasty in the monitored patients were healed. In 6 patients, an ingrowth of fibrous tissue of 2-4 mm in width in the convexity of the cup was detected. The mean survival of the revision oval-shaped cup - TC type with a follow-up of 8.2 years after the reimplantation based on Kaplan-Meier analysis was 91.4 %. DISCUSSION The number of revision total hip arthroplasties due to a younger age of patients who undergo alloplasty keeps growing. The choice of a revision implant should always match the intraoperative finding and the bone tissue quality. The standard uncemented implants with osteoactive surface can be opted for when anterior and posterior column of the acetabulum are intact (IIA and IIB according to Paprosky). Starting from type IIC, also the proximal part of acetabulum shall be considered. At our department, preference is given to the revision cup - TC type. The oval shape facilitates a lower degree of bone resection and easier restoration of the anatomical centre of rotation. Careful debridement of granulating and necrotic tissue, thorough treatment of bone defects and osteoactive surface of implants in case of adequate primary fixation of the cup substantially contribute to the quality of its osseointegration. Greater rigidity of fixation verified by pull-out tests enables to insert angular stable screws into the gaps in the proximal part of the cup. There is still room for improvement in treating the bone defect. The application of allogenic bone grafts into the defects and spaces between the ribs of the TC cup is more challenging than the use of augmentation in the systems with trabecular titanium. Based on the evaluation of CT scans, remodelling of the transplanted bone occurs, therefore the defect zone is reduced. CONCLUSIONS The oval-shaped uncemented cup - type TC meets the requirements placed on a state-of the art revision implant, moreover its specific construction helps improve the conditions where another re-operation of acetabulum is necessary. By evaluating mid-term to long-term results of non-homogenous group of 36 patients (38 cups) we have obtained data on joint function comparable to similar groups with revision uncemented implants presented in our and foreign literature. Key words: revision oval-shaped cup, bone remodelling, pull-out tests, angular stable screws, computed tomography.

[Structural Damage to the Hamstring Graft due to Interaction with Fixation Material and its Effect on Biomechanical Properties of ACL Reconstruction]. / Strukturální zmeny stepu z hamstringu zpusobené fixacním materiálem a jejich vliv na biomechanické vlastnosti náhrady LCA.

PURPOSE OF THE STUDY Hamstring grafts are commonly used for ACL reconstruction. The purpose of our study is to determine the effects of the suspension fixation compared to graft cross-pinning transfixation, and the effect(s) of structural damage during the preparation of the graft on biomechanical properties of the graft. MATERIAL AND METHODS The design of the study is a cadaveric biomechanical laboratory study. 38 fresh-frozen human hamstring specimens from 19 cadaveric donors were used. The grafts were tested for their loading properties. One half of each specimen was suspended over a 3.3mm pin, the other half was cross-pinned by a 3.3mm pin to simulate the graft cross-pinning technique. Single impact testing was performed and the failure force, elongation and acceleration/deceleration of each graft was recorded and the loading force vs. elongation of the graft specimens was calculated. Results for suspended and cross-pinned grafts were analysed using ANOVA method, comparing the grafts from each donor. RESULTS The ultimate strength of a double-strand gracilis graft was 1287 ± 134 N when suspended over a pin, the strength of a cross-pinned graft was 833 ± 111 N. For double-strand semitendinosus grafts the strengths were 1883 ± 198 and 997 ± 234 N, respectively. Thus, the failure load for the cross-pinning method is only 64.7% or 52.9% for the suspension method. DISCUSSION Structural damage to the graft significantly reduces the graft strength. Also, extensive suturing during preparation of the graft reduces its strength. CONCLUSIONS Fixation methods that do not interfere with the graft's structure should be used to reduce the risk of graft failure. Key words: ACL reconstruction, hamstring graft, biomechanical testing.

[Treatment of pelvic avulsion fractures in children and adolescents]. / Lécba avulzních zlomenin v oblasti pánve a kycle u detí a dospívajících.

INTRODUCTION: Paediatric avulsion fractures of the pelvis and hip joint are rare injuries most commonly associated with a rapid muscle contraction of the respected apophysis, which is the weakest component of the growing skeleton. The chosen therapy option can be either conservative or surgical. METHODS: We present a cohort of 69 patients treated for an apophyseal avulsion fracture of the anterior superior / inferior iliac spine, the lesser and greater trochanters iliac crest and the ischial tubercle. We compared the treatment outcomes, treatment time, need for immobilisation, and complications of conservative vs. surgical treatment. RESULTS: The mean time to mobilisation was 24.5 days in the conservative and 8.5 days in the surgical group of patients. In the group of surgically treated patients, healing signs were observed as early as in week 6. As of month 4, no difference was observed between the groups in terms of the clinical and radiological outcomes. CONCLUSIONS: The treatment outcomes of both methods are comparable in the long term. Surgery is indicated in dislocations exceeding 1 cm. Faster recovery and return to sports activities is the main advantage of the surgical treatment method. Disadvantages include the necessity of general anaesthesia as well as the risk of infection and the need of the osteosynthetic material removal. The choice of the treatment method remains individual depending on the type of injury and habitual practice of the centre.Key words: avulsion fracture - child - pelvis - treatment - outcome.

[Osteochondritis Dissecans in Children - Treated with Arthroscopic Drilling]. / Osteochondritis dissecans u detí ­ osetrení pomocí artroskopické techniky fokálních návrtu.

PURPOSE OF STUDY Osteochondritis dissecans (OCHD) is an increasingly diagnosed disease among adolescent patients. It is a condition affecting subchondral bone and the lining cartilage. If left untreated, it can cause destruction of cartilage of the affected joint leading to early development of arthrosis. Mostly affected joints are knees and ankles, but affected elbow and other joints have been described too. The purpose of our study is to present the patients diagnosed and treated surgically at our clinic with arthroscopic drilling in the period 2010-2015, and subsequently the clinical findings obtained at follow-up checks after the surgery. MATERIAL AND METHODS Between 2010 and 2015, a total of 34 patients (36 joints) underwent surgical treatment at our clinic. Their age ranged from 6 to 19 years at the time of surgery, 17 girls and 17 boys underwent the surgery. All the patients were treated with transarticular antegrade arthroscopic drilling. Each patient was diagnosed based on the clinical finding, radiographs, or MRI. The patients were followed after 6 weeks, thereafter 3, 6, and 12 months after the surgery. Each patient was evaluated based on the clinical findings (presence of swelling, range of motion, and pain according to VAS), and radiographs. RESULTS The preoperative VAS was 2.9 and dropped down to 1.5 at the first follow-up visit. None of the patients complained of pain at 1-year follow-up. 34 (out of 36) patients suffered joint swelling preoperatively, 6 weeks after the surgery only 9 patients presented with ongoing swelling, at 1-year follow-up no patient reported this problem. The X-ray findings showed regression in 35 of 36 patients one year after the surgery. One female patient underwent redo surgery because of an ongoing restriction of movement and X-ray finding persistence. DISCUSSION Majority of patients with OCHD can be treated conservatively. Physical activity modification and temporary immobilization are commonly used treatment methods of this condition. If conservative treatment is unsuccessful, arthroscopy should be considered. Stable lesions have a high chance of spontaneous healing without surgery. There is a variety of arthroscopic treatment methods. Mostly transarticular transchondral drilling is used to treat this condition. CONCLUSION Treatment of OCHD with arthroscopic drilling shows promising results in our cohort of patients. We recommend to use arthroscopic drilling in patients in stage I to III according to X-ray when 3 months of conservative treatment do not improve the clinical symptoms, swelling and restriction of movement. Antegrade drilling is the most frequently used treatment method in OCHD at our clinic, we consider this technique a simple and effective, with short surgical time needed. Key words: osteochondritis dissecans, treatment, arthroscopy, drilling.

[Extraarticular Subtalar Arthrodesis with the Grice Procedure in Children with Cerebral Palsy: Mid-Term Results]. / Extraartikulární subtalární artrodéza podle Grice u pacientu s detskou mozkovou obrnou: zhodnocení strednedobých výsledku.

UNLABELLED: PURPOSE OF THE STUDY The aim of the study was to evaluate, on the basis of radiographic findings and AOFAS scores, the results of the Grice extra-articular subtalar arthrodesis for treatment of planovalgus foot deformity in cerebral palsy patients. MATERIAL AND METHODS A total of 38 patients (50 feet) with cerebral palsy indicated to the Grice procedure for planovalgus foot deformity between 2006 and 2010 were assessed. The group comprised 18 girls and 20 boys, of whom 10 had spastic quadriparesis (four undergoing bilateral surgery), three had triparesis, four had hemiparesis and 21 had diparesis (treated on both sides in eight). The average age at surgery was 12 years (range, 7 years and 2 months to 17 years and 8 months). All patients were evaluated based on the AOFAS scoring system and radiographic findings before and after surgery. RESULTS The average follow-up was 4.5 years. The average AOFAS score increased from 54.9 points pre-operatively to 76.6 points post-operatively. The pre- and post-operative average values for the talocalcaneal angle were 49.8° and 25°, respectively; for the calcaneal inclination angle they were 8.6° and 13.4°, respectively. DISCUSSION The Grice procedure has long been considered a primary surgical treatment for planovalgus foot deformity in patients with cerebral palsy. Recently, calcaneal osteotomy has been used more frequently, but with no evidence of provably better results. CONSLUSIONS The mid-term results of the Grice extra-articular arthrodesis in our group of cerebral palsy children were very good in terms of both radiographic and AOFAS score evaluation; the latter includes objective assessment as well as the patient's subjective evaluation. KEY WORDS: Grice procedure, extra-articular subtalar arthrodesis, cerebral palsy, planovalgus foot deformity.

[Vertical Talus: Mid-Term Results of Surgical Therapy]. / Vertikální talus: strednedobé výsledky operacní terapie.

PURPOSE OF THE STUDY: The aim of the study was to clinically and radiographically evaluate the results of a two-stage surgical technique used in our department to treat congenital vertical talus. MATERIAL AND METHODS: In the years 1990-2010 we treated eight patients (nine feet). We used a two-stage surgical technique, with lengthening of the dorsiflexor muscles of the leg and the tibialis anterior muscle at the first stage. This was followed by cast fixation with the ankle in plantar flexion for 6 weeks. At the second stage, through a Cincinnati approach, the talonavicular and calcaneocuboid joints were reduced and the Achilles tendon and peroneal tendons were elongated. Two patients underwent the Grice extra-articular subtalar arthrodesis at the third stage. The post-operative outcomes were assessed based on radiographic findings of dorsoplantar views of the talocalcaneal angle (TC AP) and talar axis-first metatarsal base angle (TAMBA AP), lateral views of the weight-bearing talocalcaneal angle (TC LAT), talar axis-first metatarsal base angle (TAMBA LAT) and talotibial angle (TT). In all patients but one who was lost to follow-up, the radiographic and objective findings were evaluated with the 10-point scale described by Adelaar et al. RESULTS: The average follow-up was 8 years and 9 months. All radiographic findings showed improvement in all angles measured. The pre-operative values decreased in TC AP from 64.2° to 27.6°; in TC LAT from 48.8° to 30.4°; in TT from 158° to 109.3°; in TAMBA AP from 54.7° to 17.4°; in TAMBA LAT from 57.3° to 5.7°. The Adelaar scoring system was employed in seven patients of whom three had excellent, three good and one fair results. Two patients required additional surgery due to recurrence of the deformity DISCUSSION: Studies in recent years have shown a gradual diversion from extensive surgical procedures and a trend toward techniques like manipulation, serial casting application and minimal surgical intervention with talonavicular reduction and fixation. The Dobbs technique has so far shown good results but no long-term results have yet been available and therefore the number of recurrent cases is not known. CONCLUSIONS: The two-stage surgical technique used in our department proved to be very successful in a long-term follow-up, but the group of patients was too small to provide conclusive evidence. However, benefits of this technique are clearly apparent from the post-operative radiographic and objective findings assessed as very good.

[Use of cultured human autologous bone marrow stem cells in repair of a rotator cuff tear: preliminary results of a safety study]. / Pouzití kultivovaných lidských autologních kmenových bunek kostní drene pri rekonstrukci ruptury rotátorové manzety - studie bezpecnosti metody, predbezné výsledky.

PURPOSE OF THE STUDY Rotator cuff tears are one of the most frequent shoulder disorders which are often associated with pain and interfere with proper arm function. In order to evaluate the safety and effectiveness of using cultured human autologous mesenchymal stem cells (MSC) applied to the suture site during arthroscopic repair of a rotator cuff tear, a prospective clinical study was designed and started recently at the authors' department. Its primary goal was to evaluate the safety of using cultured human MSCs, the secondary goal then was to study a therapeutic effect of their application. Preliminary results of the study on a limited number of patients are presented here. MATERIAL AND METHODS Ten patients who met the indication criteria for arthroscopic repair of a rotator cuff tear were included in the study. In addition, they also had to meet inclusion and lack exclusion criteria. According to the protocol, their bone marrow was harvested at 3 to 4 weeks before surgery. Subsequently, an arthroscopic repair of the rotator cuff tear was performed and an suspension of cultured MSCs was applied to the suture site at the end of the procedure. The isolation of MSCs from bone marrow and their cultivation was carried out by the company Bioinova, Ltd. The patients were followed up at 6 weeks and 3 and 6 months post-operatively. Their clinical assessment included physical examination of the shoulder, pain intensity evaluation according to the visual analogue scale (VAS), and subjective questionnaires for Constant and University of California (UCLA) scores. All patients underwent MRI examination at 6 post-operative months to evaluate the quality of rotator cuff reconstruction. The findings were compared with the pre-operative results. RESULTS A final evaluation was made in eight patients of 10. Two patients were excluded from the study because their exclusion criteria were fulfilled. The evaluated patients showed significantly better clinical outcomes as early as 6 weeks after surgery; also all pre-operative scores were improved at 3 and 6 months. The average values at 6 months post-operatively were: 0 points for the VAS score, 32 for the UCLA score and 84 for the Constant score. The MRI findings at 6 months after surgery showed fully healed and well-integrated tissue of the rotator cuff tendon attachment in all eight patients. No adverse effects of therapy were recorded during the follow-up period. DISCUSSION The use of autologous stem cells and growth factors in the treatment of tendons, muscles and cartilage is currently the topic of many experimental studies on animal models. Its utilisation in human clinical trials has been reported only marginally; the relevant studies have so far used only suspensions of non-cultured mononuclear cells. Our study, although on a smallsize patient group, provides evidence that human cultured autologous MSCs can safely be used for tissue repair in the indications mentioned above. CONCLUSIONS Our preliminary short-term results show that using human cultured autologous MSCs in the treatment of rotator cuff tears is safe. However, further research is needed, particularly with regard to the effectiveness of the method. Key words: rotator cuff tear, arthroscopic repair, mesenchymal stem cells, tendon, cell therapy.

[Recurrent intra-articular bleeding episodes in haemophiliacs. Treatment outcomes in the patients at the university hospital motol in 1985-2005]. / Efekt lécby recidivujícího nitrokloubního krvácení v souboru hemofiliku lécených ve FN v Motole v letech 1985-2005.

PURPOSE OF THE STUDY: Chronic synovitis is a common finding in people with haemophilia. It regularly appears after recurrent episodes of intra-articular bleeding. The bleeding originates from the subsynovial venous plexus underlying the capsule where a lack of thromboplastic activity has been demonstrated. Therefore, the changed synovium appears to be a treatment target. There are several methods which can be used to remove the synovial layer from the joint. The aim of our study was to asses the efficacy of different treatment approaches used in a group of haemophiliacs between 1985 and 2005 in our hospital. MATERIAL AND METHODS: A group of 30 patients with bleeding disorders was evaluated in the study. There were 29 men with haemophilia and one woman with von Wilebrandt factor deficiency. Their age ranged from 6 to 18 (median 13) years. They underwent a total of 68 interventions including surgical synovectomy (n=28), radionuclide synovectomy (n=33) and corticosteroid instillation (n=7). The necessity of a repeat intervention was used as a criterion of successful treatment. RESULTS: In the group of surgical synovectomies, 22% of the patients required repeat operations, in the group of radiation synovectomy, this was 9% and, in the group treated with corticosteroids, this was 43%. The average hospitalisation time was 50 days for surgical procedures (19-133 days) and 7 days for radiation synovectomy procedures (4-13 days). DISCUSSION: In 1994 Merchan presented seven excellent or good results in a group of 10 knees evaluated 1 year after treatment with methylprednisolone. Six years later he reported that "five years after completion of treatment, all results of the observed patients were poor". Generally, corticosteroids will reduce synovitis in the majority of patients but the effect is temporary. A complete remission is a very rare situation under corticosteroid treatment. The experience with surgical synovectomies is not recent and this method is described as carrying a high risk of complications and requiring a high amount of coagulating factor consumption. There are several recent reports on the application of Yttrium-90: in Madrid they evaluated treated joints (knees, ankles and elbows, n = 66) in 44 patients aged from 9 to 39 years. The results were good in less than half of the knees and ankles. The treatment of elbows was more successful. It was recommended to perform synoviorthesis at the early stages of synovitis. In Israel, they reported that a decrease in the number of bleeding episodes was achieved in 80% of 115 patients treated with Yttrium-90; in 15% of them, bleeding in the treated joints stopped completely. In Izmir, Yttrium was used in the treatment of knees, elbows, ankles and also shoulders in children and young adults (3-25 years). The method was found to be safe and effective. Brazilian authors have experience with the treatment of knees, ankles, elbows and shoulders too; they have concluded that this method represents an important resource for the treatment of chronic haemophilic synovitis and markedly reduces joint bleeding frequency and pain, irrespective of the radiographic stage and inhibitor status. While the European Association of Nuclear Medicine (EANM) recommend using 186Re-sulfide for treatment in medium-sized joints, Chinese authors have published a study comparing the effect of using three different doses of 186Re-sulfide in the treatment of chronic synovitis in knees. Their patients have received an amount of radionuclide according to the thickness of their synovial layer measured on MRI, with the result that 22 patients exhibited significant reduction in synovial thickness. A reduction in the number of bleeding episodes was reached in 71% of the patients within an 18-month period. No significant differences were found among the groups receiving different radioactivity doses. In Turkey, 35 elbows, 26 ankles and two shoulders in 49 patients aged between 3 and 30 years were treated with 186Re. The patients were followed up from 6 months to 3 years. At 6 months after the procedure, 81% of the elbows and 86% of the ankles with grade II synovitis were free from bleeding, as well as 53% and 44% of the elbows and ankles with grade III synovitis, respectively. CONCLUSIONS: Radiation synovectomy appears to be the method of choice in the treatment of recurrent bleeding in the joint cavity in people with haemophilia. The efficacy of surgical synovectomy is lower in comparison with radiation synovectomy. Risks associated with surgery and anaesthesia, the need of hospitalisation and a prolonged period of rehabilitation are bothering. On the contrary, the application of corticosteroids cannot be recommended as a good method to treat recurrent haemarthroses.

Xenogeneic protein-free cultivation of mesenchymal stromal cells - towards clinical applications.

We have studied a rapid cultivation method for human mesenchymal stromal cells based on CellGroTM medium and human serum, supplemented with insulin, ascorbic acid, dexamethasone, epidermal growth factor, platelet-derived growth factor BB, macrophage colony-stimulating factor and fibroblast growth factor 2. This study has shown that rapid expansion of human multipotent mesenchymal stromal cells using human serum could not be achieved without addition of growth factors. Furthermore, we have found that insulin and, quite probably, epidermal growth factor may be omitted from our formula without loss of colony-forming capacity or total cell yield. On the other hand, dexamethasone, ascorbic acid and fibroblast growth factor 2 were necessary for the growth and colony-forming capacity of multipotent mesenchymal stromal cells, while platelet-derived growth factor BB prevented their differentiation into adipogenic lineage. Moreover, multipotent mesenchymal stromal cells cultivated in our system expressed higher levels of bone morphogenetic protein 2, but not bone morphogenetic protein 7, than cells cultivated in α-MEM with foetal bovine serum. This shows that our system promotes differentiation of mesenchymal cells towards osteogenic and chondrogenic lineages, making them more suitable for bone and cartilage engineering than cells grown in conventional media. Furthermore, we have proved that these cells may be conveniently cultivated in a closed system, in vessels certified for clinical use (RoboFlaskTM), making the transfer of our cultivation technology to good clinical practice easier and more convenient.

[Oblong acetabular cup, type TC, for revision total hip arthroplasty]. / Pouzití oválné TC jamky pri revizních operacích totálních náhrad kycelního kloubu.

PURPOSE OF THE STUDY: Revision total hip arthroplasty is a demanding surgical procedure. It involves a massive loss of acetabular bone stock associated with primary implant removal, and a complicated revision cup fixation in the highly damaged surrounding bone. The authors describe the use of a novel oblong acetabular cup, type TC (Trc-Cingr), for replacement of a loose acetabular component. The aim of the study is to present this novel implant with evaluation of the first clinical results and to report on the authors' experience with revision arthroplasty assessed at 24 to 62 months of follow-up. MATERIAL: The TC cup was used in revision total hip arthroplasty in 40 patients treated between February 2004 and June 2007. Aseptic loosening of a cemented cup was an indication for surgery in the majority of patients. The first 10 treated patients were supervised, according to the strict rules of good clinical practice, by the State Institute for Drug Control. A total of 31 patients were evaluated. There were 20 women and 11 men with an average age of 68 years (range, 41 to 81 years) at the time of primary implantation. METHODS: At the end of 2009, 31 patients were evaluated at a follow-up of 24 to 62 months (average, 44.8 months) after revision surgery. The patients' age, gender, body mass index, physical activity, diagnosis for indication, implant size and intra- and post-operative complications were recorded. The development of secondary implant stability was assessed on X-ray films taken at 3, 6, and 12 months and then at 1 year after surgery. Attention was paid to implant and screw positions and potential implant migration and signs of osteolysis around the cup and screws. An objective assessment of the results was obtained by comparing the pre- and post-operative values of the Harris hip score (HHS). RESULTS: A femoral component was replaced together with a revision cup in 20 patients. The average HHS value increased from 41.86 points pre-operatively to 82.70 points post-operatively. The results were recorded as excellent in six, very good in 17, satisfactory in six and poor in two patients. The radiographic findings showed good bone-implant integration in 26 patients and radiolucent lines . 1mm in width in DeLee zone 3 in three patients. In one overweight patient, discontinuity of two proximally inserted screws, but no detectable implant migration, was recorded. There was only one case of proximal migration of the TC cup, with osteolysis detected around all screws (Paprosky type 3B defect). DISCUSSION: The acetabular cup is the most frequently re-implanted component in our country. This is due to a high proportion of total hip arthroplasties with the previous frequent use of a cemented POLDI prosthesis whose neck in a valgus position probably played its role in increased wear of the cup. Acetabular bone defects are usually extensive and the operative tactics are based on the Paprosky classification. Type 3A and 3B defects, exceptionally also type 2C defects, are most serious and acetabular cup replacement is most difficult. The oval-shaped uncemented TC cup was developed with the objective to reconstruct defects on the bottom of the acetabulum, with stable and firm primary fixation of the implant secured in bone with implant augmentation screws and additional fixation screws. Good primary fixation with bone grafting to fill defects and spaces between implant ribs should facilitate bone remodelling in the close vicinity of the cup. A minimum of 24 months after revision cup implantation is regarded as sufficient for an objective evaluation of hip function and radiographic evidence of good bone-implant integration. CONCLUSIONS: The results show good applicability of the oval-shaped implant which is easy to implant, maintains good primary fixation and allows for good bone remodelling in its vicinity.

[Arthroscopic technique using crossed K-wires for avulsion fractures of intercondylar eminence in children]. / Artroskopická lécba avulze interkondylické eminence u detí za pouzití zkrízených Ki-drátu.

PURPOSE OF THE STUDY: Avulsion fractures of the intercondylar eminence (ICE) of the tibia have become increasingly frequent in older school age. Due to recent advances in arthroscopic techniques, it is now possible to treat them by minimally invasive methods. This retrospective study presents evaluation of clinical outcomes of an arthroscopic technique using crossed K-wires. MATERIAL: Thirty-five patients with ICE avulsion fracture, 17 girls and 18 boys at an average age of 13 years (7-18), were included in this study. All were indicated for surgical treatment on the basis of radiographic evidence of McKeever type II and III fractures. METHODS: The technique of arthroscopic reduction and fixation with crossed K-wires was used. The clinical evaluation of knee stability (anterior drawer test and Lachmann s-test) was made by one clinician. The modified Tegner-Lysholm score was assessed. RESULTS Of the 35 patients, 26 (74%) had minimal knee instability (anterior drawer up to 5 mm), two patients were primarily converted to open reduction with good results, and three (8.5%) experienced temporary knee instability (anterior drawer of 5-10 mm) that resolved spontaneously within 24 months of surgery. Four patients (11.5%) had symptoms of persistent residual instability (anterior drawer more than 10 mm) and were indicated for anterior cruciate ligament reconstruction at a later stage. The average Tegner-Lysholm scores were 86.3/100 and 98.6/100 at 6 and 24 months, respectively. DISCUSSION At the present time at our department, McKeever type II and III avulsion fractures of the intercondylar eminence are indicated for minimally invasive surgical treatment. By exact reduction it is possible to decrease the risk of post-operative knee instability. The current trend is the use of arthroscopy-assisted minimally invasive techniques such as the method of K-wire fixation described here. CONCLUSIONS: Arthroscopic surgery for ICE avulsion fractures shows good results, is associated with low post-operative risks, is minimally invasive and easy to reproduce. It can be recommended as the method of choice for treating ICE avulsion injury in children.