[Total Replacement of the First Metatarsophalangeal Joint by Medin PH-Flex and Its Effect on Forefoot Biomechanics in the Propulsion Phase of the Gait Cycle]. / Totální náhrada prvního metatarzofalangeálního skloubení Medin PH-Flex a její vliv na biomechaniku prednozí v propulzní fázi krokového cyklu.

PURPOSE OF THE STUDY Total arthroplasty of the first metatarsophalangeal joint is one of the surgical treatment options for patients with advanced hallux rigidus. This study evaluates the pressure changes in the propulsion phase of the gait cycle using dynamic pedobarography after the total arthroplasty of the first metatarsophalangeal joint by Medin PH-Flex and their comparison with the control groups of patients with hallux rigidus and with asymptomatic patients. MATERIAL AND METHODS Dynamic pedobarograph was used to evaluate 15 first MTP joint replacements by Medin PH-Flex implants in 12 female patients, the average time since joint replacement was 3.5 years (1.5 to 5.5 years). The control group consisted of 13 forefeet in 12 patients with hallux rigidus of Grade 3 and Grade 4 according to the Coughlin classification and 17 healthy patients with no clear foot deformity, i.e. of a total of 34 forefeet. A zone for each metatarsal (M1-M5) and the big toe area (T1) were defined with the use of an integrated software. The difference between the pressure under the big toe area and the first metatarsal bone - hallux stiffness (T1-M1) and the forefoot balance parameter, i.e. the difference between the pressures under the medial and lateral half of the forefoot ((M1+M2)-(M3+M4+M5)), was obtained. The parameters were evaluated for each group during the propulsion phase of the gait, i.e. from 55% to 100% of the stance phase and from 75% to 100% of the stance phase, i.e. that part of propulsion when the greatest pressure is exerted on the big toe. RESULTS For the HS parameter (T1-M1) in 55% to 100% of the stance phase, the median value was -0.66 ± 1.22 (-1.90 to 1.45) in the control group, -0.85 ± 1.94 (-1.40 to 3.80) in patients with hallux rigidus, and -0.10 ± 1.48 (-1.30 to 2.40) in patients after the first MTP joint replacement. The median forefoot balance parameter from 55% of the stance phase was -3.48 ± 2.45 (-6.90 to 0.68) in healthy patients and -4.43 ± 2.72 (-6.98 to 0.23) in hallux rigidus patients. In patients after the joint replacement, the value was -3.00 ± 2.46 (-6.20 to 0.40). The data were statistically analysed by the Dunnett's and Tukey's multiple comparison tests. The hallux stiffness parameter showed a significant improvement after the joint replacement compared to patients with hallux rigidus (p<0.0001). No statistical significance was confirmed when comparing the joint replacement cases and the healthy patients from the control group (p=0.0007 and p=0.0010, respectively). As concerns the forefoot balance parameter, a significant difference was reported in patients with joint replacement compared to healthy patients from the control group and patients with hallux rigidus (p <0.0001). DISCUSSION The published pedobarographic studies differ in terms of the methodology used, the patient population and the parameters examined. The pedobarographic studies after the replacement of the first MTP joint or after its arthrodesis present inconclusive outcomes. According to the available literature, the joint replacement has the potential to improve mediolateral forefoot loading and to partially restore the weight-bearing function of the first ray. Our analysis of the HS parameter suggests that the MTP joint replacement can improve the big toe function compared to patients with hallux rigidus but fails to achieve the functional outcomes of healthy patients. When evaluating the forefoot balance (FB) parameter, we can observe less loading on the lateral half of the forefoot in the propulsion phase compared to hallux rigidus. Nonetheless, the joint replacement is unable to restore the physiological loading of the foot. CONCLUSIONS The first MTP joint replacement has the potential to improve forefoot function and to bring it closer to that of a healthy person, even though achieving physiological loading of the forefoot is unrealistic. Additional studies will be needed to confirm that the indication for the first MTP joint replacement is justified in hallux rigidus in terms of the effect on forefoot biomechanics. Key words: hallux rigidus, total replacement of the first MTP joint, dynamic pedobarography, footscan.

[Native Joint Septic Arthritis in Adults: Incidence in Our Group of Patients and Antibiotic Therapy Guidelines]. / Infekcní artritidy nativních kloubu u dospelých: výskyt v nasem souboru pacientu a doporucení antibiotické lécby.

PURPOSE OF THE STUDY The purpose of the study is to analyse the number of adult patients treated in our department for native joint septic arthritis and to outline guidelines for antibiotic therapy. MATERIAL AND METHODS From the beginning of 2003 to the end of 2020, a total of 36,342 surgeries were performed at our department. We retrospectively reviewed and analysed all surgeries for native joint septic arthritis (a total of 538 surgical interventions). The study included all adult patients who were operated for native joint septic arthritis in our department in 2003-2020. We included all revision surgeries for ongoing infection (excluding the management of post-infectious findings) as well as all operations performed in patients with multiple joint involvement. Based on the analysis of our data and review of published guidelines for antibiotic treatment of septic arthritis, we have outlined our own antibiotic therapy guidelines for the treatment of native joint septic arthritis. RESULTS From 2003 to 2020 we performed a total of 36,342 surgeries, of which 538 (1.5%) in 461 patients was indicated for native joint septic arthritis. The cohort consisted of 292 men (63%), who underwent 344 surgeries, and 169 women, in whom 194 surgeries were performed. The mean age of patients irrespective of the arthritis location was 62.4 years. Altogether, 19 patients (4.1%) suffered from multi-joint arthritis. The most frequently operated joint was the knee with 252 (54%) patients and 300 surgeries (56%), followed by the shoulder with 68 (14.7%) patients and 78 (14.5%) surgeries, the hip with 38 (8.2%) patients and 42 surgeries (8%), the carpal with 30 (6.5%) patients and 35 (6.5%) surgeries, the ankle with 25 patients (5.4%) - 31 (6%) surgeries, the small finger joints with 22 (4.75%) patients and 23 (4%) surgeries, the elbow with 14 (3%) patients and 14 (2.6%) surgeries, the sternoclavicular joint with 9 (1.9%) patients and 12 (2.2%) surgeries and the acromioclavicular joint with 3 patients and 3 (0.5 %) surgeries, respectively. DISCUSSION The management of septic arthritis relies heavily on early diagnosis, early surgical intervention and adequate antibiotic therapy. The diagnostic process and surgical treatment have their specifics related to the affected location, therefore, respective guidelines will be published separately for each location including the results. On the other side, antibiotic management is not dependent on the location and therefore the guidelines are included in this first analysis septic arthritis in the whole cohort. CONCLUSIONS Septic arthritis in adults in an ongoing issue with rising incidence. Early diagnosis, urgent and adequate surgical treatment, and optimal antibiotic therapy are preconditions for successful outcome. Key words: native joint septic arthritis, incidence, antibiotic therapy, guidelines.

[Minimally Invasive Hallux Valgus Surgery: First Experience]. / Miniinvazivní operace hallux valgus: první zkusenost.

PURPOSE OF THE STUDY The Minimally Invasive Chevron Akin (MICA) is a percutaneous technique used to correct hallux valgus deformity. The combination of distal osteotomy of the first metatarsal and the proximal phalanx of the big toe stabilized with internal fixation was used over the last decade. The retrospective study presents the results of measurements performed on preoperative and postoperative X-rays and offers a comparison with conventional osteotomies. MATERIAL AND METHODS The study population consists of 76 patients who underwent 93 operations between 2015 and 2018 at the Department of Orthopaedics, 1st Faculty of Medicine, Charles University in Prague. The mean age of patients was 50.2 years (range 18-74 years). The study evaluates and measures the parameters and the attributes of interest on weight-bearing X-rays of the foot before and after the operation at 6-week or 3-month follow-ups. The first intermetatarsal angle was measured according to the mechanical and the anatomic axis of the first metatarsal bone. Apart from that, the displacement of the first metatarsal head in the osteotomy, hallux valgus angle and distal metatarsal articular angle were analysed. The position of the medial sesamoid bone and the congruency of the first metatarsophalangeal joint were evaluated as well. RESULTS The mean hallux valgus angle was 33.2° ± 7.3° and 10.2° ± 5.8° postoperatively. The mean value of the first mechanical intermetatarsal angle decreased from 12.4° ± 2.8° to 7.4° ± 2.5° postoperatively. The mean value of the first anatomic intermetatarsal angle increased from 13.7° ± 3.6° to 17.4° ± 4.6°. The used technique restored the congruency of the first metatarsophalangeal joint in 85 cases (91%). The mean lateral displacement of the metatarsal head fragment was 50% of its width (range 18% to 84%). The mean X-ray exposure during the operation was 0.58 mGy and the personnel were exposed to radiation for 79 seconds on average. DISCUSSION One of many questions raised with regard to hallux valgus surgery is the choice of the right technique in order to achieve proper position of the big toe. The surgeon should have the opportunity to use a technique that provides the possibility to change orientation of the metatarsal head articular surface in three anatomic planes. Our study found out that the displacement of the metatarsal head using the MICA technique in transversal plane is from 4 mm to 18 mm (in 20 mm diameter of the head). The method thus offers a possibility to correct mild, moderate and partially severe deformities as well. The main disadvantage of the method is the necessity to use a C-arm at the operating theatre. CONCLUSIONS The Minimally Invasive Chevron Akin (MICA) is a percutaneous technique to correct hallux valgus deformity based on two extraarticular osteotomies of the proximal phalanx of the big toe and the distal part of the first metatarsal bone. The method using stable internal fixation with two screws offers a possibility to change the orientation of the articular surface of the metatarsal head in sagittal, transversal, and even in frontal plane, and is useful to correct mild and moderate deformities. Key words: hallux valgus, minimally invasive technique, percutaneous technique, chevron osteotomy, Akin osteotomy.

[Outcomes of Revisions of the Acetabular Component of THA with Paprosky Type 3a and 3b Defects Using Tantalum Trabecular Metal Implants 2-10 Years Postoperatively]. / Výsledky revizí acetabulární komponenty TEP kycle s defekty Paprosky 3a a 3b pomocí trabecular metal tantalových implantátu 2­10 let po operaci.

PURPOSE OF THE STUDY Tantallum trabecular metal implants (Trabecular Metal Technology - TMT) considerably changed the acetabular reconstruction options in revision surgeries with extensive bone defects and distorted pelvic ring integrity. The purpose of this study is to ascertain the short-term to medium-term outcomes of acetabular reconstruction through TMT implants in patients with Paprosky type 3a and 3b acetabular defects and in case of pelvic discontinuity. MATERIAL AND METHODS The prospective monocentric study included patients in whom the revision of acetabular components in total hip arthroplasty was performed, the acetabular defect was classified as Paprosky 3a and higher, a TMT implant was used for reconstruction, and the follow-up period was at least 2 years after surgery. In total, 87 patients who had met the inclusion criteria were operated on and followed-up. The patients in the study group underwent a clinical examination, an X-ray and also an assessment using the Harris hip score. Moreover, the patients were asked about their satisfaction with the surgical outcome, their willingness to undergo the same procedure again in case of difficulties, and they were also asked to rate the outcome in percentage term and by assigning grades. Also, an analysis of the reasons for revision and subsequent complications was carried out. Implant integration and its migration were evaluated on an X-ray. RESULTS 32 men and 55 women were subjects to evaluation, with a balanced number of operated sides (44:43 in favour of the right side). One-stage procedures prevailed, which were performed in a total of 74 cases, while two-stage revisions were performed in 13 cases in the study group. In three patients (3.5%) pelvic discontinuity was diagnosed, 69 patients (79%) suffered from Paprosky 3a defect and 15 patients (17%) from Paprosky 3b defect. The first patients underwent surgery in 2009 and the mean follow-up period in the study group was 48 months. In 1 patient the TMT implant was removed for infectious complications, in the remaining part of the group the TMT implant was fully integrated with no signs of loosening or migration in the monitored period. In the assessment using the Harris hip score, the mean score of 80.4 (range 36-99) was achieved. When assessing the satisfaction with the surgical outcome, the mean value achieved was 94.4%, and the mean assigned grade was 1.26 (on a school grading scale). DISCUSSION Extensive bone defects and pelvic discontinuity represent an issue in revisions of the acetabular component in total hip arthroplasty. There are several options how to address these conditions. State-of-the-art TMT implants thanks to their shortterm and medium-term outcomes appear as one of the most beneficial option with a low failure rate both in our study group and in published papers. CONCLUSIONS Evaluation of this monocentric prospective study reveals encouraging short-term and medium-term outcomes of the use of TMT implants in managing extensive acetabular bone defects of Paprosky 3a and 3b type and supports their further introduction into practice at our department. Key words: total hip arthroplasty (THA), revision implantation, TMT implant.

[Our Experience with the Total Replacement of the First Metatarsophalangeal Joint by Medin PH-flex]. / Nase zkusenosti s totální náhradou prvního metatarzofalangeálního kloubu palce PH-flex Medin.

PURPOSE OF THE STUDY: The first metatarsophalangeal (MTP) joint replacement ranks among the treatment methods of patients with hallux rigidus. The paper aims to evaluate the short-term to mid-term outcomes and to present clinical experience with our Medin PH-flex implant. MATERIAL AND METHODS In the period from January 2011 to 2016 we performed total replacement of the first MTP joint in 31 patients, in 4 cases bilaterally. In total, 35 implants were evaluated. The mean age of the patient at the time of surgery was 57.7 years (39-72 years). The surgery was conducted in 29 women and 2 men. The patients were evaluated using the AOFAS score (American Orthopaedic Foot and Ankle Society score), the radiographs were assessed as to the potential occurrence of radiolucent lines, with major stress put on the assessment of the mobility in MTP joint and its position. The pain was assessed based on the VAS score. RESULTS Prior to the joint replacement surgery, the mean AOFAS score in patients was 55.6 (35-65). Postoperatively, the mean AOFAS score was 80.8 (65-95). The pain suffered by patients was evaluated with the use of the Pain Visual Analogue Scale (VAS score). The preoperative mean VAS score was 5 (2-8), whereas the postoperative score improved to mean VAS 2 (0-4). The range of motion was clinically assessed with a goniometer. The mean range of motion of plantar flexion and dorsiflexion was 16.00° (5-35°) and 28.60° (10-55°), respectively. The mean range of motion was 36° (15-60°). No intraoperative complications were observed. In all the patients, the surgical wound healed per primam. In 2 female - (5.7 %) of the whole group of patients who underwent surgery a deep infection occurred, namely 10 and 21 months following the implantation. In both the female patients their condition was managed by joint revision operation and by a simple removal of the implant. DISCUSSION Joint replacement related matters were repeatedly discussed in professional literature. There are many papers published in the literature on this topic. A whole range of the first MTP joint implants of different shapes have been developed, with extremely different clinical results. CONCLUSIONS An appropriately chosen type of the implant, a fitting indication and a correctly applied implantation technique can lead to the desired good outcome. The first MTP joint replacement should be indicated after careful consideration since the management of a potential joint replacement failure can often be very technically challenging and quite mutilating for the patient. The mid-term outcomes of the Medin a.s. first MTP implant seem to be promising. It will, however, be necessary to wait for long-term outcomes in order to evaluate the final benefits of this type of implant in patients with hallux rigidus. Key words: hallux rigidus, arthroplasty of the MTP joint, hemiarthroplasty, silicone implant.