Mesh fixation in laparoscopic reconstruction of inguinal hernias.

INTRODUCTION: Laparoscopic inguinal hernia repair is a widely used surgical technique, although not exempt from potential complications. The aim of our study was to compare our postoperative results according to the fixation method of the prosthetic material. METHODS: This is a retrospective study. We looked up 167 patients who underwent laparoscopic inguinal hernioplasty between 01 Jan 2015 and 31 Dec 2016 at the Surgical Department of Vsetin Hospital. The patients were invited for a follow-up visit after 46 weeks and a questionnaire was sent them after 933 months. We evaluated any development of postoperative hematoma, recurrent hernia and pain after one month and during the first year from the surgery in dependence on the fixation method (stapler Pro Thick, acrylic glue Glubran, 3D light mesh). RESULTS: In total, 120 patients were enrolled in the study, 22 in the Glubran group, 59 in the stapler group and 39 in the 3D group. A hematoma developed in 10% in the stapler group, while there was none in the other groups; the difference was statistically significant (p=0.0382). Recurrent hernia was found in 5% in the Glubran group, 3% in the stapler group, and 0% in the 3D group; no statistically relevant difference was found. No difference was demonstrated for postoperative pain, either. CONCLUSION: Long-term postoperative results after TAPP were not found to differ in recurrence rates and pain based on the used fixation material in our set of patients. The stapler was associated with a higher risk of postoperative hematoma, but it was a preferred method in all cases of large hernias.

Novel Cu(II)-based metal-organic framework STAM-1 as a sulfur host for Li-S batteries.

Due to the increasing demand for energy storage devices, the development of high-energy density batteries is very necessary. Lithium-sulfur (Li-S) batteries have gained wide interest due to their particularly high-energy density. However, even this type of battery still needs to be improved. Novel Cu(II)-based metal-organic framework STAM-1 was synthesized and applied as a composite cathode material as a sulfur host in the lithium-sulfur battery with the aim of regulating the redox kinetics of sulfur cathodes. Prepared STAM-1 was characterized by infrared spectroscopy at ambient temperature and after in-situ heating, elemental analysis, X-ray photoelectron spectroscopy and textural properties by nitrogen and carbon dioxide adsorption at - 196 and 0 °C, respectively. Results of the SEM showed that crystals of STAM-1 created a flake-like structure, the surface was uniform and porous enough for electrolyte and sulfur infiltration. Subsequently, STAM-1 was used as a sulfur carrier in the cathode construction of a Li-S battery. The charge/discharge measurements of the novel S/STAM-1/Super P/PVDF cathode demonstrated the initial discharge capacity of 452 mAh g-1 at 0.5 C and after 100 cycles of 430 mAh g-1, with Coulombic efficiency of 97% during the whole cycling procedure at 0.5 C. It was confirmed that novel Cu-based STAM-1 flakes could accelerate the conversion of sulfur species in the cathode material.

[Trochanteric femoral fractures]. / Trochanterické zlomeniny femuru.

At the present time proximal femoral fractures account for 30% of all fractures referred to hospitals for treatment. Our population is ageing, the proportion of patients with post-menopausal or senile osteoporosis is increasing and therefore the number of proximal femoral fractures requiring urgent treatment is growing too. In the age category of 50 years and older, the incidence of these fractures has increased exponentially. Our department serves as a trauma centre for half of Prague and part of the Central Bohemia Region with a population of 1 150 000. Prague in particular has a high number of elderly citizens. Our experience is based on extensive clinical data obtained from the Register of Proximal Femoral Fractures established in 1997. During 14 years, 4280 patients, 3112 women and 1168 men, were admitted to our department for treatment of proximal femoral fractures. All patients were followed up until healing or development of complications. In the group under study, 82% were patients older than 70 years; 72% of those requiring surgery were in their seventies and eighties. Men were significantly younger than women (p<0.001) and represented 30% of the group. The fractures were 2.3-times more frequent in women than in men. In the category under 60 years, men significantly outnumbered women (p<0.001). The patients with pertrochanteric fractures were, on the average, eight years older than the patients with intertrochanteric fractures, which is a significant difference (p<0.001). The mortality rate within a year of injury was about 30%. Trochanteric fractures accounted for 54.7% and femoral neck fractures for 45.3% of all fractures. The inter-annual increase was 5.9%, with more trochanteric than femoral neck fractures. There was a non-significant decrease in intertrochanteric (AO 31-A3) fractures. On the other hand, the number of pertrochanteric (AO 31-A1+2) fractures increased significantly (p<0.001). A total of 1 394 fractures were treated with a proximal femoral nail; a short nail was used in 1260 and a long nail in 134 of them. A dynamic hip screw (DHS) was employed to treat 947 fractures. Distinguishing between pertrochanteric (21-A1, 31-A2) and intertrochanteric (31-A3) fractures is considered an important approach because of their different behaviour at reduction. Pertrochanteric fractures occurred more frequently (81.5%); the patients' age was higher (80 years on the average) and women outnumbered men at a ratio of 3:1. Intertrochanteric fractures were found in significantly younger patients (average, 72 years), with a women-to-men ratio of 1.3:1. Stable pertrochanteric fractures (31-A1) were preferably indicated for DHS surgery. Unstable pertrochanteric (31-A2) and intertrochanteric (31- A3) fractures were treated with a nail. The patients underwent surgery on the day of injury or the next day. In the case of contraindications to an urgent intervention, surgery was performed after the patient's medical condition had stabilised. The number of complications was largely related to technical errors, such as insufficient reduction or an incorrectly inserted implant. Intertrochanteric fractures were associated with a higher occurrence of complications. No implant can compensate for errors due to surgery. Serious complications can be reduced by the correct assessment of fracture type, the use of an appropriate operative technique and early treatment of potential complications. The necessity of restoring continuity in the medial cortex of the femoral neck (Adams' arch) is the requirement that should be observed. Pseudoarthrosis or varus malalignment in a healed hip should be managed by valgus osteotomy. When the femoral head or the acetabulum is damaged, total hip arthroplasty is indicated. A prerequisite for successful surgical outcome is urgently and correctly performed osteosynthesis allowing for early rehabilitation and mobilisation of the patient.

[Arthroplasty for intracapsular fractures of the femoral neck. Current concept review]. / Aloplastika u intrakapsulárních zlomenin krcku femuru.

The authors discuss arguments concerning indications and selection of implants and operative techniques for arthroplasty in the treatment of femoral neck fractures. Their analysis is based on long-term experience with surgical treatment of patients with hip fractures and on the evaluation of a large number of publications by well-known specialists. The assessed group included 4795 patients treated at their institution between 1997 and 2010, of whom 1532 underwent hip replacement, with 1032 receiving hemiarthroplasty (HA) and 500 having total hip replacement (THR) indicated for femoral neck fractures. A painful hemiarthroplasty due to acetabular cartilage erosion and subsequent head protrusion is still a challenging clinical problem. The most important factor in prevention of this complication remains strict adherence to indication criteria. A metal monoblock hemiarthroplasty should be indicated only in very old patients with serious co-morbidities or in patients whose pre-operative mobility has been greatly restricted. For the other cases, a modular prosthesis is preferred because it allows for more exact alignment and, if necessary, its conversion to a total hip prosthesis is relatively easy. The stem to be implanted should be the one used in standard THR procedures. A ceramic modular head then enables hemiarthroplasty to function for long with a low risk of cartilage erosion and head protrusion. Even if the choice of an optimal prosthesis, in terms of its biomechanical and biological properties, has been correct, the prosthesis' long life span and good functioning still depends on the surgeon's adherence to the principles of the correct operative technique (the head centre situated 1 to 2 mm below the level of the apex of the greater trochanter, 12- to 15-degree anteversion, articular capsule suture, and re-insertion of external rotator tendons if the Koch-Langenbeck approach is used. This is the only way of minimising acetabular erosion and other complications. Indications for total replacement include, in addition to fractures at joints affected by arthritis, most often a displaced fracture of the femoral neck found in younger patients still in good general health with a good prospect for a long life. Even if dislocation and loosening occur in these patients more often than in those with a THR procedure indicated for other reasons (primary or post-dysplastic arthritis), this therapy offers fewer complications and longer functioning in comparison with other methods of treating femoral neck fractures. A cemented prosthesis can be regarded as the standard implant; however, if the proximal femur shows good quality cortical bone, an uncemented implant can be used without a greater risk of future loosening. In the absence of hip arthritis which leads to the development of subchondral sclerosis required for the correct acetabular cup fixation, a hybrid THR with an expansion cup or a screw-in cup is recommended.

[Reccurent tibial osteomyelitis after the segmental bone transport: a radical interdisciplinary treatment]. / Rekurentní osteomyelitida tibie po transportu kosti a její radikální interdisciplinární lécba.

Long-term or recurrent osteomyelitis results in the deterioration of soft tissue quality at the site of an infectious process. An insufficient perfusion of the scar tissue contributes to difficult treatment of osteomyelitis. A local transpositional or free muscle flap used to replace the vulnerable scar tissue will enhance perfusion of the affected bone and will help to control osteomyelitis. The authors present the case of a patient who had been treated by bone transport for a 14-cm-long segmental defect of the tibia after post-traumatic osteomyelitis. Recurrent osteomyelitis was found nine years after the primary surgery. The whole tibial cavity was opened leaving a 12-mm-wide trepanation opening, and debridement of all necrotic and inflammatory tissue including dystrophic skin was performed. The Orr technique was used for further treatment. There was no relapse and granulation tissue samples repeatedly gave negative culture results. Therefore, at the second stage, the soft tissue defect was covered with a free latissimus dorsi muscle flap. Anastomoses to the recipient vessels were technically difficult to carry out in the tissue greatly affected by previous chronic inflammation. Ten days after the surgery the patient was allowed to stand and walk, full weight-bearing was allowed at 2 months post-operatively when the flap was completely integrated. At 6-year follow-up the extremity was fully weight-bearing, with no recurrence of infection, and the patient was satisfied with the outcome. The authors regard this interdisciplinary management (extensive bone and soft tissue debridement, free muscle flap transfer) as a method indicated for the treatment of recurrent tibial osteomyelitis.

[Medial opening-wedge high tibial valgus osteotomy, using a stable TomoFix plate, in genu varum arthritis: surgical technique]. / Valgizacní vysoká osteotomie tibie u genu varum arthroticum rozevrením klínu z vnitrní strany stabilizovaná úhlove stabilní dlahou TomoFix: Operacní technika.

The authors present the technique of high tibial correction osteotomy by the medial opening procedure, with the use of an angle-stable TomoFix plate. The prerequisite for a long-term good outcome of corrective osteotomy in genu varum is to achieve limb alignment permitting transfer of weight-bearing from the affected medial compartment to the healthy lateral compartment of the knee. The development of implants that maintain a stable angle has facilitated corrective osteotomy with an opening wedge on the medial side of the proximal tibia. These implants provide stable fixation even when a high correction of the mechanical axis is needed. The authors present the case of a patient with varus malalignment following a fracture of the tibia. In order to achieve correction of the limb's mechanical axis, it was necessary to open the proximal tibia osteotomy with a wedge that was 2.5 cm on the outer side.

The European school of total hip arthroplasty and 35 years of total hip arthroplasty in the Czech Republic.

The development of the European total hip arthroplasty in the sixties of 20th century is associated mainly with the names of G. K. McKee, J. Charnley and M. E. Muller. The SICOT meeting in Paris in 1966 introduced THA as a new method of treatment of osteoarthritis of the hip and paved the way for the commercialization of the manufacturing of prostheses. The success of this method consisted primarily in the fixation of individual components by bone cement and application of metal-to-polyethylene and metal-to-metal joints. The book presents these historical events as they have been reflected in the development of THA in the countries of the former Czechoslovakia and in the development of implants of domestic provenance. The development of THA in the former Czechoslovakia started in 1969 and was based on the Swiss school established by M. E. Muller. The Muller component with the "banana-shaped" stem was implanted using the Watson-Jones approach, the proximal femur canal was prepared by a rasp and the Palacos cement was used. This prosthesis served also as the model for the first Czech implant Poldi-Cech of I generation (the Chirulen cup available in three sizes, the "banana- shaped" femoral component with a 32 mm head-diameter and 130 degree neck-shaft angle) the development of which started in 1969 and the serial production began in 1972 in the Poldi Kladno steel company. Fatigue fractures of the "banana-shaped" stem led to the development of the concept of a femoral component with an "anatomical" stem. In Switzerland, this concept was developed by B. G. Weber. In the former Czechoslovakia the development of a new femoral component with an "anatomical" stem following the shape of the intramedullary canal with an ovoid profile and without sharp edges started in 1972. Due to the incidence of fatigue fractures of the "banana-shaped"stem and material that was not sufficiently strong (steel used for the production of osteosynthetic components), 144 degree neck-shaft angle was chosen. Reduction of the effect of bending forces on the valgus stem had eliminated fatigue fractures. This Poldi-Cech prosthesis of II generation was provided in nine sizes. The diameter of the head remained the same. Three Chirulen cups were supplemented with a "flat" cup for implantation in a dysplastic acetabulum. The prosthesis was implanted with an exact instrument set (reamer for acetabular preparation, rasp for proximal femoral preparation, alignment device for accurate positioning of both the cup and the femoral component) with the use of the Palacos cement. The production of the Poldi-Cech prosthesis of II. generation started in 1974 with the fabrication of a monoblock. Since 1986 it has been developed into a modular system (14/16 cone) with the possibility to use a ceramic head of 32 mm diameter (only in the nineties the cone size was changed to 12/14 and the heads were provided also in the 28 mm diameter). The Poldi-Cech prosthesis of II generation with the "anatomical" stem has been implanted since 1974 (i. e. during 30 years) in more than 140 000 patients in the Czech and Slovak Republics. In the same year cemented monoblock hemiarthroplasty was developed on the same basis as THA using the same "anatomical" stem and 36 to 60mm head diameter. Until now more than 35,000 of these hemiarthroplasty systems have been implanted. Until 1992 the Poldi-Cech implant was practically the only available cemented total hip replacement in the former Czechoslovakia and retrospectively it may be considered a highly successful implant. In the authors' view, the further development of THA will lead in the following years to the use of implants proved by a long-term follow-up. Preference will be given to prostheses the implantation of which will require a minimal loss of the bone stock during primary surgery and which will allow a technically easy reimplantation. The continental Europe has been recently preferring hybrid prostheses while Scandinavia witnesses an evident increase in the number of implanted cemented prostheses to the detriment of the cementless and hybrid ones. Naturally, cementless prostheses will keep dominating in young patients.

Morphological features of bone healing under the effect of collagen-graft-glycosaminoglycan copolymer supplemented with the tripeptide Gly-His-Lys.

The authors prepared 7.5% and 12.5% collagen gel, and supplemented it with the tripeptide Gly-His-Lys (GHK), perfloxacine and hypersulphated glycosaminoglycan (HSGAG). By means of 125l marking, its absorption was followed from small polyurethane sponges placed under the skin of rats. The absorption of gel without HSGAG was found to be faster. Antibodies against collagen (type I, II and III) or collagen gel were generated either in rabbits or in minipigs, in which collagen gel was tested. Microbiological tests proved the sterility of the collagen gel. The collagen gel supplemented with GHK, pefloxacine and HSGAG was named Colladel, and was used in a model experiment in guinea-pigs for filling artificially created bone defects in diaphyses of femurs, and with cementless endoprostheses. The healing process was followed by means of RTG and NMR, and histologically. The slowest healing process was found in unfilled bone defects. Defects filled with Colladel without GHK healed substantially more quickly, and the most accelerated healing was connected with complete Colladel application. When Colladel was used with cementless endoprostheses, vivid osteogenic activity at the interface of trabecular bone and metal stem was detectable in the course of the experiment.

[Extended Bauer Approach and Transfemoral Approach in THA Revision.]. / Rozsírený Baueruv prístup a prístup transfemorální pouzívaný námi pri revizních operacích TEP kycelního kloubu.

The number of revision surgeries of the hip joint keeps growing and it brings new problems, especially in cases where the skeleton in the region of the loosened stem is destructed. As we have been pursuing total hip arthroplasty in the Czech Republic for 30 years we know that the life of the implants is reduced, the number of aseptic loosening is increasing. This loosening is associated with the loss of the bone stock, mainly the cortex gets thinner. The revision cemented stem cannot be exactly fixed in the destructed proximal femur and, in addition, the bone is further damaged. Wagner introduces a new concept of the treatment of these severe complications: transfemoral approach, cementless implant - a stem which may be fixed distal to the destruction of the proximal femur. This method provides prerequisites for the formation of the new bone - bone regeneration and the regeneration of the destructed femoral bone stock. The author presents an extended Bauer approach he has been using in revision surgeries since 1983 (in cases where the bone stock has been preserved and the broken stem of the implant or the persisting remnants of the bone cement have to be removed). This technique is used also in the transfemoral approach which differs from the Wagner approach by performing transfemoral osteotomy in the coronal rather than sagittal plane. It allows operating on the patient in the supine position - similarly as during primary implantation. It provides the possibility of a reliable replacement and alignment of the loosened cup and the revision of the medullary canal from the transfemoral approach in the coronal plane, removal of the bone cement, polyethylene granuloma and an exact application of the Wagner stem. It means that the stem must be fixed below the osteotomy level, extending over 10 cm, but minimally 7 cm proximally to the isthmus of the medullary canal. This extended transfemoral approach requires the Wagner stems in the length of 265 mm and 305 mm. With the use of the Wagner stems of the length of 190 mm or 225 mm this approach is usually not indicated. Key words: revision surgery, transfemoral approach, Wagner stem.

[Treatment of an infected pseudoarthrosis defect by callotasis of the bone fragments]. / Lécba infikované defektní pseudoartrózy kalotaxí fragmentu kosti.

The authors demonstrate a method of filling a large total bone defect caused by resection of the bone on account of chronic osteomyelitis. The defect was filled with a regenerate prepared by calotassis of the fragment which was distracted from the proximal part of the bone to its distal part. It proved thus possible to fill a 16 cm long defect. The cosmetic, anatomical and functional result is excellent.

[A sandwich-type hip joint socket with a ceramic lining]. / Sendvicový typ jamky kycelního kloubu s keramickou vlozkou.

The authors present a new type of sandwich socket with ceramic lining. Mechanical tests provide evidence that the submitted implant is very firm. It is a basic prototype from which cemented and non-cemented sockets of the hip joint will be derived. The authors use a 28 mm socket paired with a 28 mm head and 12/14 conus and 14/16 Euroconus. This means that the submitted socket is compatible with all types of cemented and non-cemented endoprostheses.

[Development of the ceramic sandwich cup used for the hip joint prosthesis.]. / Vývoj keramické sendvicové jamky pro náhradu kycelního kloubu.

The abrasion of the polyethylene seems to be the most important factor participating on the endoprosthesis loosening. From this reason, the ceramics (AI2O3) was introduced for the both parts of the prosthesis, i. e. the head and the cup. It appears that the friction resistance is an important factor for the comparison of the hitherto applied endoprosthesis designs with the new developed type. The frictional resistance in the hip joint total prosthesis was measured by means of a testing device which allowed a swinging motion of the ceramic ball in the tested cup in the range of +/-25 degrees . This measurement was carried out at the loading levels being 0; 500; 1000; 1500 and 2000 N. For the comparison of the frictional resistance of single measured couples "cup-head", the energy consumed was ascertained which was necessary for including a swinging motion over the time interval of 35 sec. Ceramic cups manufactured by a. s. DIAS Turnov were used for the measurement. Altogether eight couples "ceramics-ceramics" having the diameter differences ranging from 0,022 mm to 0,137 mm and one friction couple "polyethylene cup-ceramics ball" were measured. The research of influence of different lubricants was also done. Key words: sandwich cup, total prosthesis, ceramics--ceramics, bioceramics, frictional resistance.

[Dorsal stabilization in multiple metastases of the thoratic spine in prostate carcinoma.]. / Dorzální stabilizace u vícecetných metastáz karcinomu prostaty v hrudní páteri.

The authors used successfully since 1991 for the treatment of injuries of thoratic spine (Th-1) dorsal instrumentation by means of an internal AO fixation device (Dick's fixation device). In some injuries e. g. fractures at several levels, pathological fractures and in particular in metastatic processes or spondylolistheses its application is limited. Since 1995 in the authors' department in these instances a new USS system is used. The latter makes it possible to fix several levels above each other, it is variable and flexible, has a lawer profile and volume. It ensures sufficient stability. Key words: bone metastases, spine, stabilization.

[Experimental and clinical study of the Poldi isoelastic cervico-capital endoprosthesis. II. Clinical study]. / Experimentální a klinická studie izoelastické cervikokapitální endoprotézy POLDI. II. cást: Klinická studie.

In the second part of the paper on isoelastic cervicocapital prostheses the authors describe a group of patients with an implanted endoprosthesis. The selection of indication for implantation was very strict and the group of patients is very homogeneous. The endoprosthesis was implanted to biologically old patients with fractures of the neck of the femur where it was not possible to select treatment other than implantation of a cervicocapital prosthesis. The group of patients was evaluated subjectively according to a questionnaire sent to the first 50 patients, and objectively, i.e. by analysis of the clinical and radiological examination. A total of 85 patients were evaluated after more than two years after the implantation. Clinical examination revealed in almost 60% of the patients pain in the central part of the femur of changing quality. For evaluation of the effect the authors assessed the ability to walk and the quality of gait. Despite the above mentioned complaints 76% of the patients were able to walk unaided. By evaluation of the X-ray findings the authors did not only find evidence of osteoplastic reactions in the region surrounding the bone but also the probable cause of pain suffered by the patients, i.e. inadequate contact of the inner corticalis of the femoral cavity of varying width with the uniform shank. The most serious complication was fracture of the shank of the endoprosthesis, always at a typical site. This occurred in five patients from a total of 130 operated ones, i.e. in 3.8%. Modifications which led to the solution of this problem influenced, however, the elasticity and applicability of this prosthesis. Further investigations made in this group are compared in the discussion in great detail with available data on all other three so-called isoelastic prostheses used in other countries world-wide. In the conclusion the authors evaluate the positive and negative aspects of the endoprosthesis and they emphasize the necessity of certain technical modifications needed for future use of this type of implant.

[Valgus osteotomy in the treatment of sequelae of ischemic post-dysplastic necrosis of femoral head in children. Part I: surgical technique.]. / Valgizující osteotomie pri lécení následku ischemické postdysplastické nekrózy hlavice stehenní kosti u detí: I. cást - operacní technika.

The authors deal with the surgical technique of the reconstruction of coxa vara in children. They present valgus osteotomy on the Pauwels principle with the simultaneous apophyseodesis of the growth plate of greater trochanter, lengthening of fermoral neck fixed by 120 degrees angled blade plate for adolescents allowing a parallel lengthening of the lower limb. The main indication for this technique is postdysplastic coxa vara and congenital coxa vara in children. However, it may be used also in adults. The benefits of the method consist in the possibility of exact planning of the surgery. Key words: valgus osteotomy, reconstruction, DDH, ischemic necrosis of the femoral head.

[Treatment of closed fractures of the shin external fixation.]. / Lécení zavrených zlomenin zevní fixací

In their communication the authors present a method used for the treatment of closed fractures of the shin by the method of external osteosynthesis, its indication criteria and the actual technique of operation. Open reduction is the method of choice in cases of early treatment of instable fractures of the shin with a good condition of skin cover and other soft tissues. Closed reduction is the method of choice in those patients the treatment of which is postponed (by more than 3 weeks) and in fresh injuries combined with a more extensive damage of soft tissues associated with oedema of the extremity often with a segmental type of fracture. For a very suitable method the authors consider the combination of internal miniosteosynthesis by a compression screw with neutralization external esteosynthesis. Key words: closed fractures, external fixation, miniosteosynthesis.

[Reoperation of Cemented Total Endoprosthesis of the Hip Joint Part I. X-ray Diagnostics and the Classification of Loosening.]. / Reoperace cementované totální endoprotézy kycle I. Rtg-diagnostika a klasifikace uvolnení

The authors monitored a group of 87 patients after a reoperation of the total replacement of the hip joint due to the so-called aseptic loosening of one of the components. On the basis of the evaluation of clinical complaints and an x-ray finding of the extent and progress of the so-called radioluscent line on the cement-bone interface and their correlation with the peroperative finding of the loosening of the implant they developed an x-ray classification of the loosening of the total endoprosthesis. This three-grade classification facilitates the consideration of the latest state of the fixation of the implant and the prognosis of further development. It is a therapeutical guideline for the determination of the period suitable for reoperation and possible exchange of endoprosthesis. Key words: total endoprosthesis of the hip joint, aseptic loosening, diagnostics.

[Hybrid replacement of the hip joint of the poldi-cech system.]. / Hybridní náhrada kycelního kloubu systémem Poldi-Cech.

The authors present cementless endoprothesis of the hip joint from the new series of hybrid endoprothesis of the hip joint being developed. The endoprothesis has a conic shaft allowing - with a precise reaming of the medullary canal by means of pneumatic reamer - good primary stability which provides the prerequisites for the remodellation of the bone bed. Endoprothesis is produced from the titanium alloy Ti-5 AI-2,5 Fe. The replacement is indicated for biologically young patients with a solid skeleton. Key words: hybrid endoprothesis, titanium alloy Ti-5 AI-2,5 Fe, cementless endoprothesis.

[Unstable pertrochanteric fractures, biomechanic, classification and therapy.]. / Nestabilní pertrochanterické zlomeniny -jejich biomechanika, klasifikace a terapie.

The authors deal with unstable pertrochanteric, intertrochanteric and subtrochanteric fractures extending as far as calcar femorale. The treatment of pertrochanteric issues is a serious issue as their total number in the Czech Republic exceeds 5.000 annually and with the exception of those which are contraindicated due to their health condition, all patients are indicated to surgery. In the treatment of unstable pertrochanteric fractures there occurs failure of internal fixation also with the use of implants such as dynamic hip screw or Gamma nail. The cause of unsuccessful treatment of unstable fractures is the defect in calcar femorale - impairment of the weightbearing area of proximal femur and failure of the implant as a result of its cyclic overloading - breakage of the nail, cutting out of the screw from the head in the osteoporotic bone or breaking out of screws fixing the plate to the femoral shaft. For a causal procedure the authors consider the reconstruction of the calcar femorale by a wedge valgus osteotomy of the comminuted zone after the original design of Debrunner and Cech (1969). Simultaneously with reconstruction of the medial cortical support in the calcar femorale the 160 degrees valgization is performed. In the AO classification the authors consider for unstable the fractures of types 31.A2.1, A2.2, A3.3. Significant from the therapeutic viewpoint is the classification of stable fractures (with open reduction the anatomic reconstruction of weight-bearing calcar femorale is possible) and unstable fractures - where with open reduction the defect of calcar femorale persists. For stabilization of unstable the authors recommend fixation by DHS at 150 degrees angle. If need be, this fixation may be combined with lag screws and in case of a simultaneous fracture of greater trochanter and in reverse fractures a trochanteric buttress plate has to be added. Key words: unstable pertrochanteric fractures, nonanatomic valgus reduction, DHS fixation.