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D Pokorný

Publications and source records attributed to D Pokorný.

14 recordsLinked to original sources
PubMed2006

[Three-dimensional geometry of the proximal humerus and rotator cuff attachment and its utilization in shoulder arthroplasty].

PURPOSE OF THE STUDY: The aim of the study was to provide a method of measurement and data collection, based on morphologic analysis of the proximal humerus, that would facilitate precise placement of the humeral stem and would be easy to apply in clinical medicine in patients requiring shoulder arthroplasty. MATERIAL: Three groups of materials were used. Materials for the first and second groups were provided by the Department of Anatomy, First Faculty of Medicine, Charles University. The first group included 10 specimens (five left and five right humeral bones) obtained at routine anatomical dissection. The second group contained 110 so-called dry preparations from the collections of the Department of Anatomy and the third group comprised nuclear magnetic resonance (NMR) scans of 20 patients. To show spatial relationships between the proximal and the distal humerus, another coil was applied to the epicondylar region in addition to the one placed over the proximal humerus. METHODS: The first group material was used to study proximal humerus morphology and to determine reference points for the other two groups. The points were constructed to make seven planes perpendicular to the axis of the proximal humeral metaphysis. Based on the reference points, parameters of the proximal humerus were assessed in the defined planes also in the other two groups. We measured angles between the reference points and the transepicondylar line or the humeral head axis. The vertex of each angle was always placed in the point of intersection of the metaphyseal axis and the given transverse plane. Reference points of the greater tubercle were marked on the medial margin continuous with the intertubercular groove, on the lateral margin of the lesser tubercle and in the "deepest" place of the intertubercular groove. We also measured humeral head retroversion and the position of maximal bony mass of both the greater and the lesser tubercle (this parameter can be used with advantage for optimal insertion of screws in proximal humerus reconstruction). RESULTS: The angle between the medial margin of the greater tubercle and the humeral head axis was on average 164.8 degrees on the left side and 163.2 degrees on the right side; the angle between the great tubercle margin and the transepicondylar line was 137.0 degrees on the left humerus and 137.7 degrees on the right humerus. The lateral margin of the lesser tubercle and the humeral head axis formed on average an angle of 124.4 degrees and of 122.6 degrees on the right and the left side, respectively. The intertubercular groove/ humeral head axis relationship was 143.4 degrees and 144.8 degrees for the left and the right humerus, respectively, and the intertubercular groove/transepicondylar line angle was 115.6 degrees for the left and 119.5 degrees for the right humerus. The humeral head axis and the transepicondylar line made an angle of 27.8 degrees for the left and 25.3 degrees for the right humerus. These values corresponded to the angle of the humeral head retroversion. The reference point of maximal bony mass of the greater tubercle and the humeral head axis made an angle of 181.1 degrees and of 180.2 degrees for the left and the right humerus, respectively; between this point and the lesser tubercle was an angle of 120.2 degrees for the left and 126.9 degrees for the right humerus. DISCUSSION: One of the most important parameters in restoring shoulder function by alloplasty is humeral head retroversion. If this is not correct, ventral or, less frequently, dorsal instability of the shoulder may result. The correct setting of retroversion is guided by the transepicondylar line or several specific landmarks on the greater and the lesser tubercle of the humerus. Another important factor is the correct reconstruction of anatomic position of the greater and the lesser tubercle in relation to the insertion of rotator cuff muscles into the humeral head. Relationships of diaphyseal, metaphyseal and humeral head axes have been reported in the relevant literature dealing with proximal femoral morphology. None of the reports, however, has dealt with tubercular angles and position of the maximal body mass, which is a decisive factor for insertion of screws fixing the prosthetic stem. CONCLUSIONS: The values provided here can be used for a more precise construction of implants for shoulder replacement. The method of three-dimensional presentation of the proximal humerus may aid in a more exact implantation procedure during shoulder arthroplasty. An optimal position of the implant can also be based on parameters obtained from the healthy contralateral shoulder joint.

Anthropometry↗
PubMed2006

[Antibiotic treatment for prevention of infectious complications in joint replacement].

Prophylactic antibiotic treatment is mandatory in every operation involving an orthopedic implant. Carefully selected and correctly administered antibiotics can provide effective protection of the implant from bacterial colonization. The prevention of deep wound infection in joint replacement includes several procedures and measures which constitute three basic groups: 1) Promotion of patient's ability to resist infection (careful pre-operative preparation, elimination of potential infectious loci, good nutritional status, etc). 2) Optimal conditions for the operative wound (surgical technique, prophylactic antibiotics). 3) Reduction of the number of bacteria brought in the wound (control measures, super-sterile operating theatres). Clear rules for the system of prophylactic antibiotic treatment should be adopted. A program in which responsibility for antibiotic administration was shifted from the nursing staff to the anesthesiologist in the operating theatre showed improved outcomes and reduced costs. Poor timing of prophylactic antibiotic administration is one of the basic mistakes. If the wound happened to be contaminated during surgery, the first three post-operative hours would be most decisive for the development of infection. An effective bactericidal concentration of antibiotic should be present in tissues and serum immediately after surgery has begun. Therefore the appropriate time for antibiotic application is before a skin incision is made, and not after the operation has started; the highest serum and bone tissue levels appear 20 to 30 min. after intravenous antibiotic injection. To allow antibiotics to reach target tissues, they should be introduced at least 10 min. before tourniquet application. For long surgical procedures or when blood loss is high, an additional dose of antibiotics is recommended during the operation. If a sample for bacterial cultivation is required, antibiotic administration is postponed until during surgery. However, this is used only in indicated cases when deep infection is suspected and no assessment of the causative agent is available. Otherwise this approach carries a high risk of infectious complications in aseptic revision arthroplasty. Long-term, unjustified administration of antibiotics leads to an increase in resistance to the antibiotic involved. Some studies show that a day's course is as effective as a seven-day one. A shorter antibiotic course decreases the costs, reduces side-effects and minimizes the development of resistance. An optimal duration of antibiotic treatment has not been defined yet, and is still a hot issue for discussion. Many authors recommend one pre-operative antibiotic dose and, according to the kind of antibiotic, agree to its 24-hour administration in order to lower the toxic effect of antibiotic and to prevent selection of resistant microorganisms. The choice of suitable antibiotics for prophylactic treatment should be based on the range of agents causing joint replacement infections and the pharmacological properties of the drug. This should have minimal toxicity, should be well tolerated by the patient and, from the epidemiological point of view, should have a low risk of inducing resistance because of frequent use. Naturally, it is not possible to include all antibiotics against all causative agents and therefore attention should be paid, in the first place, to Gram-positive bacteria, i. e., staphylococci and streptococci, which are the most common causes of infectious complications associated with joint replacement. Because of difficulties related to the right choice of antibiotic, it is recommended to keep a record of complications in each patient in order to provide feedback and to facilitate the establishment of reliable antibiotic-based prevention. The prevention of infection in orthopedics is a comprehensive issue. It cannot be expected that prophylactic antibiotic treatment will compensate for mistakes made in operative protocols, for inadequate operative techniques, for shortcomings in operating theatre equipment or insufficient preparation of patients.

Antibiotic Prophylaxis↗
PubMed2006

[Method for assessment of distribution of UHMWPE wear particles in periprosthetic tissues in total hip arthroplasty].

PURPOSE OF THE STUDY: Aseptic loosening of implants is the main complication affecting the longevity of joint prostheses. The highest proportion of loosening occurs due to osteolysis produced by the presence of ultra-high molecular weight polyethylene (UHMWPE) wear particles smaller than 1 microm. These can be identified by microscopic, spectroscopic or light-scattering methods. Here we describe our method for counting wear particles, based on the principle of light scattering. MATERIAL AND METHODS: Between 2002 and 2004, we collected samples of polyethylene granuloma in 19 patients who underwent revision total hip arthroplasty (THA) for aseptic loosening. The samples were obtained from strictly defined areas corresponding to the radiographic presentation of periprosthetic zones describes by Gruen and DeLee in THA. The frozen samples were lyophilized and subjected to delipidation and hydrolyzation procedures in 65 % HNO3. The top part of solution containing wear particles was blended with isopropanol, and the mixture was filtered through a 10-microm polycarbon membrane. Subsequently, the filtrate was filtered through a 0.1-microm membrane. Membranes with trapped particles, 0.1 to 1.0 microm in size, were sent for particle characterization and quantification. The number of wear particles was measured by the method based on light scattering with calibration (LSC), using a Beckman Coulter LS230 analyzer that can express particle size distribution in a given volume in percent. The method was based on the fact that each particle reflects rays that can be measured. The medium measured contained an unknown number of UHMWPE particles and a known number of calibration glass beads varying in size. The number of UHMWPE particles was calculated from the known number of calibration beads. RESULTS: Because the collected samples were also used to develop the method, comprehensive data was obtained in six patients only. Particle distribution recorded in the periprosthetic zones in THA varied greatly; up to a five-fold difference in particle concentration was observed between the zones. In five of the six patients, the highest particle concentration was found in zone III. DISCUSSION: Seeking a method that would be exact, quick and cheap and would eliminate particle aggregation remains the subject of study for researchers cooperating with clinical practice. At present methods based on weighing isolated particles are used most frequently. We developed the LSC method that, for quantification, utilizes the ability of particles to disperse light, and allows us to calculate the real numbers of UHMWPE wear particles in a medium containing a known number of calibration particles. Although this is an indirect method, it gives more accurate results than the direct weighing of particles. The advantages of the LSC method involve less demand on sample purity, greater speed and low limits of detection. The method is useful for statistical evaluation of a larger number of samples. The variation in particle distribution in THA found in this study is in agreement with the relevant literature data; it is also in agreement with our assumptions and clinical findings. CONCLUSIONS: The authors developed an original method for assessment of UHMWPE wear particles in tissue samples, which is quicker than the methods so far used. In the periprosthetic tissues studied, particles about 1 microm in size were detected; their numbers (about 1010 particles per gram dry tissue) are in agreement with the literature data. The distribution of particles in periprosthetic zones in THA was uneven. The highest number of particles was found in the neighboring zone III and zone 7, as described by Gruen and DeLee. Key words: wear, polyethylene, total hip arthroplasty, light scattering, aseptic loosening, wear particles.

Arthroplasty, Replacement, Hip↗
PubMed2006

[Linezolid in the treatment of antibiotic-resistant gram-positive infections of the musculoskeletal system].

PURPOSE OF THE STUDY: The growing incidence of resistant microorganisms has been responsible for complications associated with treatment of osteomyelitis, infections following joint arthroplasty, as well as septic arthritis. Their therapy often requires a long-term administration of antibiotics to which the bacterial strain is sensitive. Oxazolidinons present a novel group of antibiotics recently adopted in clinical medicine. However, the only member of this group so far approved for clinical use is linezolid. It is effective for Gram-positive bacteria including antibiotic-resistant strains, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), resistant coagulase-negative staphylococci and penicillin-resistant pneumococci. Linezolid is well absorbed in the intestinal system. Oral administration results in serum levels comparable with those following intravenous injection of the same dose. MATERIAL, METHODS AND RESULTS: In the 1st Orthopedic Department of the 1st Faculty of Medicine at Charles University, linezolid was used for treating infections of the musculoskeletal system caused by MRSA and methicillin-resistant Staphylococcus epidermidis (MRSE). Fourteen patients, eight women and six men, were treated in the period from 1999 to 2005. The average age at the time of therapy was 65 years (range, 24-80). The treatment involved infection of 10 joints following arthroplasty (six total hip and four total knee replacements), one osteomyelitis, one septic arthritis, one abscess in the gluteal region and one infected amputation stump. With the exception of one patient, antibiotic therapy was always combined with an appropriate surgical intervention. The average antibiotic course was 27 days, with intravenous administration of linezolid at the beginning (average, 11.4 days; range, 9-14) and oral administration later (average, 15.9 days; range, 14-18). Antibiotic therapy was well tolerated by the patients, and no adverse side-effects were recorded. The success rate of therapy was 93 %. The only failure was in the patient in whom the infection of total knee replacement was treated with mere antibiotics, without any surgical intervention. DISCUSSION: Linezolid is a treatment option for joint infections following arthroplasty that are caused by resistant bacterial strains, such as MRSA, MRSE or VRE. The therapeutic efficiency varies in relation to whether the patients have undergone conservative or surgical treatment and, in the latter case, on the surgical technique used. On the basis of our results we suggest that a radical surgery is necessary, but in agreement with other recent reports we prefer a surgical approach combined with antibiotic therapy. The costs of linezolid treatment are high, but the possibility of its oral administration, with maintenance of the required tissue levels, markedly reduces hospital stay costs and increases patients' comfort during treatment. In our group, the patients received linezolid doses orally for up to 16 days, which means a hospital stay shorter by more than two weeks. The antibiotic course varies and, in relation to the kind of infection, may range from 5 days to 2 months; however, linezolid administration for 4 to 8 weeks is most frequent. The period of 28 days recommended by the manufacturer is thus usually extended. CONCLUSIONS: Infections caused by Gram-positive bacteria resistant to common antibiotics present serous epidemiological, therapeutic and economic problems, which will soon be in the focus of attention in the majority of Czech hospitals. In the patients who, due to allergic reactions, intolerance or bacterial resistance, cannot be treated with vancomycin or other antibiotics, linezolid may be a useful option for treatment of musculoskeletal system infections. The possibility of linezolid administration in oral doses markedly reduces hospital stay costs and increases patients' comfort during treatment.

Acetamides↗
PubMed2005

[Seven-year clinical experience with the SVL/Beznoska implant for total knee arthroplasty].

PURPOSE OF THE STUDY: The aim of the study was to evaluate our seven-year experience with the anatomic, non-constrained SVL/Beznoska implant for total knee replacement. MATERIAL: A total of 374 cemented total knee replacements, using the SVL/Beznoska implant, were evaluated in 333 patients treated at the First Orthopedic Clinic Charles University in Prague, during a seven-year period. In addition, a patellar replacement was used in five of these patients. Included in the evaluation were also eight non-cemented and hybrid SVL/Beznoska implants used 6 years ago. METHODS: The aim of the study was to evaluate the results in terms of implant function. Therefore, the longevity of implants was assessed by Kaplan-Meier's survival analysis. Another criterion was the flexion achieved. To be able to compare our clinical results involving the SVL/Beznoska implant with other, foreign types of implants, the patients were evaluated on the basis of the New Jersey Orthopaedics Hospital Knee Evaluation System. RESULTS: The Kaplan-Meier's survival score was evaluated. The mean maximum flexion achieved in the patients with SVL implants was 107 degrees . The evaluation by the New Jersey Orthopaedics Hospital Knee Evaluation System showed excellent outcomes in 269 (72 %) patients, good outcomes in 79 (21 %) patients, satisfactory in 19 (5 %) and poor in 7 (2 %) patients. There was no mechanical failure of the implant, such as break of an implant or dislocation of a PE component. Six infected implants and four aseptic loosenings were recorded. Three patients diagnosed with an infected total knee replacement had been treated for rheumatoid arthritis for a long time. One patient was on dialysis for renal insufficiency and one had erysipelas. DISCUSSION: The results of our group with the SVL/Beznoska implant were compared with those obtained from the group of 63 patients who underwent total knee arthroplasty with the LCS implant. In these patients, the mean maximum flexion achieved was 105 degrees , and the criteria of the Knee Evaluation System showed excellent outcomes in 81 %, good in 16 % and satisfactory in 3 % of the patients. No unsatisfactory outcome was recorded. Considering the fact that the LCS implant was used only in younger and active patients, the outcomes achieved with the SVL/Beznoska system can be regarded as very good. Of the six patients with infectious complications, three were treated with immunosuppressive therapy for rheumatoid arthritis, one was on dialysis for renal insufficiency and one experienced a flare-up of erysipelas. CONCLUSIONS: The most important outcome of the evaluation of 374 total knee replacements, using the SVL implant carried out at the First Orthopedic Department of the First Faculty of Medicine, Charles University, was the finding of a perfect function of all components in all patients treated. None of the complications occurring in our group was associated with the use of this implant.

Adult↗
PubMed2004

New fast method for determination of number of UHMWPE wear particles.

Ultra-high molecular weight polyethylene (UHMWPE) wear particles are the major cause of total joint replacement (TJR) failures because the wear particles, released from TJR's, cause bone loosening. To simplify the study of the relationship between numbers of particles at various locations around TJR's and extent of bone loosening at these locations, the authors of this work tried to develop a new method for easy and fast determination of number of wear particles. The method, called LSC (Light Scattering with Calibration spheres), is based on light scattering of a suspension of wear particles and calibration spheres, and yields relative numbers of particles. A modified LSC method, called LSCm, requires one additional experiment, a gravimetric analysis of a mixture of all studied samples, to determine absolute numbers of wear particles. LSC and LSCm methods are easy and fast, which make them suitable for processing and comparing high number of samples.

Calorimetry, Differential Scanning↗
PubMed2004

[A cannulated articulating spacer--a functional implant for treatment of infected hip joint prostheses].

PURPOSE OF THE STUDY: Two-stage revision arthroplasty with the use of a spacer is generally accepted as a reliable method for treating infected hip replacements. Spacers made from antibiotic-loaded bone cement give good results in treatment of deep infections, but this technique is demanding in terms of spacer shaping. In addition, the conventional spacer may dislocate or fracture during patient mobilization. We attempted to avoid the disadvantages of conventional spacers by the construction of a cannulated articulating spacer. This is a special implant consisting of a polyethylene acetabulum, a stem, a modular neck and a head. Both the acetabulum and stem are covered with antibiotic-impregnated bone cement. They are subsequently pressed into the bone bed to make impression in the cement. The union of the bone bed with cement, which occurs in conventional implantation, must be avoided. This is achieved by making movements with the implant attached to an insertion handle, and by irrigating the operative field with large volumes of saline. A drain inserted in the canal running along the stem long axis facilitates continuous lavage of the medullary cavity. MATERIAL AND METHODS: A total of 11 patients with deep infection of a hip replacement were treated with the use of a cannulated articulating spacer in the years 2002 and 2003. Seven patients had late hematogenous infections and four had chronic delayed infections. The drains providing lavage stayed in place for about 10 to 12 days or less when three consecutive cultivations of drainage discharge were negative. Antibiotics were administered for at least 6 weeks according to the results of CRP and FW assessment. The reimplantation was planned on the basis of laboratory and clinical findings. The outcome was evaluated using the Harris hip score. RESULTS: Infection was successfully eradicated in all cases. The average time during which the cannulated articulating spacer was in place was 9.4 weeks. The results, as rated by the Harris hip score, were very good; after reimplantation, the average score was 95.1 points (range, 92 to 99). Even better evidence of the advantages of this method was provided by the increase in the average Harris hip score, which was 35.3 points (range, 26 to 69). No spacer dislocation or any other mechanical complication associated with the implant were recorded. DISCUSSION: Our results achieved with the cannulated articulating spacers developed in our department, as compared with conventional ones, show that the articulating spacer provides the patient with greater comfort and, therefore, improved quality of life for the period between the removal of a loose prosthesis and reimplantation of a definitive one. This method markedly reduces the risk of failure or dislocation of the temporary implant. In comparison with the PROSTALAC system, which is difficult to obtain and which requires complicated instrumentation, our method is simpler and less expensive. Our results show that the presence of an articulating spacer as a foreign body has no effect on the efficacy of treatment for deep infection. CONCLUSIONS: The procedure for preparing a cannulated articulating spacer described here is a modification of the method used to treat deep infection at the site of a total hip arthroplasty; it is inexpensive and provides markedly greater comfort for the patient. The technique combines the advantages of a two-stage revision involving spacer insertion with the use of lavage. Because patient have no major complaint and there is low risk of implant failure, the method allows us to adjust the reimplantation timing to the course of infection eradication and patients' overall health status.

Anti-Bacterial Agents↗
PubMed2004

[Shoulder arthroplasty in traumatological indications, surgical technique].

PURPOSE OF THE STUDY: Shoulder arthroplasty in traumatological indications has a considerably worse prognosis than when the indication is osteoarthritis or rheumatoid arthritis. The problem lies in the technique of rotator cuff reconstruction and the restoration of adequate bio-mechanical properties of the shoulder joint. In this study, the difficult reconstruction of four-part fractures of the proximal end of the humerus was improved by the development of a new type of shoulder joint endoprosthesis. MATERIAL AND METHODS: Our endoprosthesis permits fixation of bone fragments of the greater and lesser tubercles to the shaft and to the diaphyseal fragment by using screws or a toothed plate designed for this purpose and produced in various shapes. In addition to the modularity of the head, the endoprosthesis has a component facilitating better recovery of biomechanical properties of the proximal end of the humerus, and this is a variable neck of the prosthesis. The modularity of the neck makes it possible to adjust the colodiaphysal angle and to adjust the head in relation to the stem in eight different positions. The shoulder replacement described, produced in two modifications by ProSpon (Czech Republic) and MIL (France), was used in surgical treatment of 43 acute fractures and 33 cases of post-traumatic destruction. The clinical outcome was assessed using the Constant rating score. RESULTS: In patients with acute trauma of a shoulder, an average of 59 points (range, 23-82) was achieved. The average maximal elevation was 88 degrees, with a range of 40 to 140 degrees. In 25% of the patients, no postoperative pain was present; mild pain at strain was reported by 73% of the patients and pain limiting the arm's activity by 3%. In patients with post-traumatic destruction of a shoulder, the average value vas 53.5 points (range, 20-88) and the average maximal elevation was 85 degrees (range, 30-130). No postoperative pain was reported by 36%, mild pain at strain was recorded in 52% and activity-limiting pain in 12% of the patients. DISCUSSION: The currently reported views are in agreement with our opinion that, at present, every method of shoulder replacement should enable the surgeon to achieve, as easy and reliably as possible, the reconstruction of fragments with the attachments of the rotator cuff. With our system, shoulder arthroplasty for the reconstruction of the proximal humerus, using the supplementary fixation components described, allowed us to treat even the most serious cases of traumatic destruction of the proximal humerus. CONCLUSIONS: To facilitate the treatment of trauma in displaced, three- or four-part fractures of the proximal end of the humerus, a new technique of reconstruction with the use of an endoprosthesis designed by us was developed. Fixation and reconstruction of fragments of the greater and lesser tubercles are carried out with screws and a special toothed plate that provides good fixation of the fragments to the stem. Compared with the current method of fragment fixation with simple suture, this technique offers an easy way of restoring the biomechanical properties in the region of the proximal end of the humerus and improves the stability of osteosynthesis. This aids in early mobilization and functional therapy of the patient, which results in a better overall outcome of the treatment.

Arthroplasty, Replacement↗
PubMed2004

[Shoulder arthroplasty in traumatological indications, long-term results].

PURPOSE OF THE STUDY: To evaluate the long-term results of shoulder arthroplasty in trauma cases, using ProSpon and MMS-M.I.L. novel systems. MATERIAL AND METHODS: The shoulder endorosthesis designed by the authors, and manufactured as two products by ProSpon (Czech Republic) and MIL (France) companies, was used in surgical treatment of 43 cases of acute fractures and 33 cases of post-traumatic conditions. The Constant score was used to evaluate the clinical outcome. RESULT: In patients with acute trauma, the average Constant score was 59 points (range, 23-82). The average maximal elevation was 88 degrees (range, 40-140). No postoperative pain, mild pain at strain and arm activity-limiting pain were recorded in 25%, 72% and 3% of the patients, respectively. In patients with post-traumatic destruction of the shoulder, the average Constant score was 53.5 points (range, 20-88) and the average maximal elevation was 85 degrees (range, 30-130). No pain, mild pain and activity-limiting pain were present in 36%, 52% and 12% of the patients, respectively. The patients in whom the reconstruction of the proximal humerus and rotator cuff was performed with the use of a special toothed plate and screws, as designed by the authors, the overall average Constant score was higher by 12 and 11 points for acute trauma and post-traumatic destruction, respectively, when compared with the conventional technique of reconstruction by suture. Two serious complications were recorded, namely, a failure of the reconstruction due to splitting of the greater tubercle fragment at the site of plate fixation and an instability of the shoulder. In patients who were indicated for shoulder arthroplasty due to post-traumatic destruction, the average increase in the Constant score was 12 points in comparison with the pre-operative status. DISCUSSION: Our results of shoulder arthroplasty in acute injury to the proximal humerus are in agreement with the results published in the literature. In reconstruction of the tubercles, there was a considerable difference in results between our screws-and-plate technique and the conventional suture method. With the former, the average Constant score was higher by 12 and 11 points and the average active elevation was better by 15 and 10 degrees for acute trauma and post-traumatic destruction, respectively. Clinical observations also show that osteosynthesis of the tubercle, particularly of the greater one, has better stability with the use of screws and plate, rehabilitation is associated with less pain and shoulder motion improves more rapidly. CONCLUSIONS: The results presented here are comparable with those reported in the literature. In the group treated by the technique designed by the authors, the outcomes are markedly better. This technique of shoulder reconstruction provides better stability for attachment fixation of the rotator cuff, facilitates reconstruction of the proximal humerus in acute trauma and restoration of biomechanical properties of the shoulder joint.

Adult↗
PubMed2003

[Polyethylene disease].

PURPOSE OF THE STUDY: The experience obtained during revision surgery and findings of polyethylene granulomas in surrounding tissues of replacement as well as marked differences in the viability of implants resulted in the study of polyethylene disease and its basic mechanisms producing the development of osteoaggressive granulomas. We investigated the morphology of particles and their number in tissues surrounding the implant. The aim of our study was to develop a method for the detection of polyethylene particles in tissues, to identify different types of wear and to assess factors that may influence the viability of joint arthroplasty in general. MATERIAL: Every revizion of joint arthroplasty performed during the last five years was evaluated in terms of the presence of polyethylene granules and the viability state of articular polyethylene inserts. A total of 55 samples were taken from tissues around loosened endoprostheses. The location of each sample was exactly determined. METHOD: A technique was developed to identify wear particles and to visualize them after all organic structures of a polyethylene granuloma were dissolved with nitrogenic acid. RESULTS: The viability of articular polyethylene implants showed extreme differences in relation to different periods of manufacture and probably also to different methods of sterilization. Articular inserts sterilized with formaldehyde (the method used at the beginning of arthroplasty in our country) showed the highest viability and the lowest wear. The polyethylene particles present in tissues surrounding the implant were characterized in terms of morphology and size. DISCUSSION: The comparison of literature data and our results has revealed that there are many unknown facts about the quality and structure of polyethylene. The method of sterilization also appears to play a role. Because the issue is complex, we were not able to identify all factors leading, in some cases, to an early and unexpected failure of the implant and we consider further investigation to be necessary. CONCLUSIONS: Polyethylene disease is an important factor limiting the viability of joint arthroplasty. It results from a complex interaction of polyethylene particles arising by wear with surrounding tissues. The particles, less than 0.5 micron in size, are phagocytized by macrophages and, by complex mechanism of expression of inflammation mediators, they result in the inhibition of osteogenesis and activation of osteoclastic processes. The previous methods of sterilization with formaldehyde vapors apparently reduced wear influenced the resistance of polyethylene to wear to a lesser degree. A method was developed to detect these particles and to characterize their morphology in the tissues of a polyethylene granuloma.

Foreign-Body Reaction↗
PubMed2003

[Two-stage reimplantation using spacers--the method of choice in treatment of hip joint prosthesis-related infections. Comparison with methods used from 1979 to 1998].

PURPOSE OF THE STUDY: Several therapies are available for the treatment of deep infection in total hip arthroplasty but none is completely successful; there is no consensus on an optimal method. The aim of this study was to evaluate the treatment used in our institution and its outcomes over the last 20 years. In each method, the success of treatment was evaluated in terms of both infection control and restoration of function in the treated joint. MATERIAL: A total of 172 patients with infected total hip replacements were treated at the First Orthopedic Clinic of the First Faculty of Medicine, Charles University, Prague, between 1979 and 1998. Our sample consisted of 132 patients, 92 men and 40 women. Resection arthroplasty was performed in 62 patients. Two-stage reimplantation was used in 64 patients. Two-stage reimplantation involving skeletal traction was applied in 35 and a block spacer was used in 29 patients. The remaining patients were treated by other techniques. METHODS: The type of infection was classified according to the Coventry system. The outcome of surgery was assessed on the basis of the Tsukayma rating system, radiographic findings and the Harris hip score. RESULTS: The average follow-up time from the definitive operation was 70.8 months. In the patients who had resection arthroplasty only, the cure rate of infection was 91.9%. However, an increase in the Harris hip score, as compared with the condition before surgery, was low (9.7 points). In the patients treated by the two-stage reimplantation without a spacer but with skeletal traction, the cure rate of infection was 94.3% and the Harris score increased by 20 points. The patients who were treated by two-stage reimplantation with a spacer showed an infection cure rate of 96.5% and an increase in the Harris score by 29 points. This increase was higher by 9 points in comparison with the patients who had reimplantation without the use of a spacer. An even greater difference (28.2 points) was found when the outcomes of this technique were compared with those of resection arthroplasty. The incidence of spacer dislocation in 21% of the cases was an unexpected finding. DISCUSSION: No great differences in outcome in terms of infection cure rate were found among the methods used, i.e., two-stage reimplantation facilitated a better function for the hip joint than Girdlestone's operation. The use of a spacer in two-stage reimplantation ensured a greater comfort for the patient during treatment and gave better results in terms of joint function than treatment without a spacer. The use of a cemented spacer is an optimal method that not only ensures the stability of a limb during the period necessary for infection control but also provides conditions for the prospective implantation of a new prosthesis. The spacer also permits delivery of high-dose local antibiotics released from the cement as well as makes space for a long-term application of antibiotic-containing lavage. CONCLUSIONS: The rate of success in the treatment of an infected hip arthroplasty and the possibility of preserving the implant and thus enabling the patient to move comfortably are currently high. The prerequisite is early diagnosis and a radical surgical approach that involves the use of a method leading to the most effective eradication of infection and the maintenance of a good function for the joint. The reimplantation of a new prosthesis, after removal of the previous one and debridement of all infected tissue and material, combined with a targeted antibiotic therapy, is the method of choice for both the patient and the surgeon.

Adult↗
PubMed1996

Wrist arthrodesis in rheumatoid arthritis. A new technique using internal fixation.

Arthrodesis of the wrist is a standard operation which is indicated for severe rheumatoid arthritis in which destruction is too advanced for more conservative procedures, or after failure of previous surgery. We have developed an L-shaped plate designed for this purpose. It provides rigid internal fixation with the wrist in the neutral position and utilises bone grafts obtained from the distal ulna and the carpal bones. We have carried out 29 successful fusions between 1992 and 1995. In all 29 patients synovectomy and resection of the head of the ulna were performed; 11 also had reconstruction of ruptured extensor tendons. All the patients obtained bony union, pain relief and improved function.

Adult↗
PubMed1989

[Noninvasive imaging methods and angiography in the diagnosis of chronic viscero-visceral arterial collateral circulation in stenosis of the celiac trunk].

Stenosis or even occlusion of truncus coeliacus represents the most frequent cause in the development of collateral blood circulation with caudiocranial flow through extended pancreatic-duodenal arcades. In a group of 32 patients with such mesenteric-coeliacal collateral circulation their arteriographic picture was evaluated. The authors evaluated differences and specific diagnostic contribution of individual visualization methods for demonstration of arteries. The non-invasive visualization methods are of exceptional contribution in the examination of abdominoretroperitoneal region by considerably decreasing the needs of invasive angiographic examination of catheterization technique. This leads to a decrease in the number of diagnosed chronically developed viscerovisceral arterial collateral circulations of various etiologies. Ultrasonography and computer tomography well depicts morphological changes in the aorta diameter as well as unpaired visceral arteries in the segment of their branching. The viscerovisceral arterial collateral circulations, however, may not be detected or at least not to a sufficient degree. They are represented in detail in the whole course only by selective arteriography. The authors draw attention to supplementary role of arteriography within the framework of non-invasive visualization methods.

Adult↗