[Total Hip Arthroplasty Using the AMIS Method: Surgical Technique, Suitability of This Method for Obese Patients, Evaluation of the Study Population]. / Totální endoprotéza kycelního kloubu za pouzití AMIS prístupu: operacní technika, vhodnost prístupu u obézních pacientu, hodnocení souboru.

PURPOSE OF THE STUDY: This manuscript aims to introduce our surgical technique, with an emphasis on the latest recommendations. The AMIS technique is discussed in more detail in patients with Class II and Class III obesity. We seek to prove the premise claiming that the anteversion and inclination values observed in this group of patients do not differ signifi cantly from those observed in patients with the recommended BMI index. We will also compare the risk of neurovascular bundle injury and postoperative complication rate regarding the surgical wound. MATERIAL AND METHODS: Patients who underwent surgery using the AMIS method in the period between 1/2020 and 4/2023 were assessed retrospectively. The study included 1150 implantations. The entire study population was assessed for neurovascular bundle injury and surgical wound healing complications. For this purpose, the patients were divided into two groups based on the BMI, namely BMI < 35 kg/m2 (n=1042) and BMI > 35 kg/m2 (n=108). In patients with the BMI ≤ 25 kg/m2 (n=280) and BMI ≥ 35 kg/m2 (n=108), the inclination and anteversion values were compared. Standard centered AP view X-rays of their operated joints were assessed. The Liaw's method was used to calculate the anteversion and inclination. RESULTS: In group one of patients with BMI ≤ 25 kg/m2 (208 women and 72 men), the arithmetic mean of acetabular anteversion was 25.4° (median 25°) and inclination was 38.3° (median 38°). In group two, which consisted of patients with BMI ≥ 35 kg/m2 (59 women and 49 men), the total arithmetic mean of acetabular anteversion was 25.1° (median 25) and inclination was 37.6° (median 37.5°). The anteversion and inclination were assessed using the Mann-Whitney test for equality of medians. The value of 0.05 was chosen as the level of signifi cance. The resulting p-value was 0.5359 in anteversion and 0.3763 in inclination. Since the p-value of both anteversion and inclination was greater than the chosen level of signifi cance, their medians have not been confi rmed to differ signifi cantly. A total of 6 cases of femoral nerve injury was reported, i.e. 0.5% out of 1150. Therefore, the risk of injury was 0.4% in the group with BMI < 35 kg/m2 (n=1042). On the contrary, in the group of patients with BMI > 35 kg/m2 (n=108), the risk was 2%. No injury to femoral artery was reported. The surgical wound healing complications were seen in a total of 87 cases (7.6%). In the group with BMI < 35 kg/m2 , healing complications of the surgical wound were observed in 7.4% of cases, with the need for revision surgery in 7 patients. In the group with BMI > 35 kg/ m2 , healing complications occurred in 13% of patients and wound revision was necessary in 4 cases. DISCUSSION: Our results are consistent with those in the published studies that also show no signifi cant difference in anteversion and inclination of components in the compared groups of obese patients. We also agree with the other authors that the rate of complications regarding surgical wound healing is higher in these patients. The risk of neurovascular bundle injury in this study population is not higher than the standard. CONCLUSIONS: The results obtained in our study population show that this method can also be used in patients with higher BMI, with no concern about the implantation of components in malposition or a higher risk of neurovascular injury. Nonetheless, potentially higher risk of surgical wound healing should be considered when this approach is opted for. With the appropriate surgical technique, AMIS is a safe method and, in our view, the fi rst choice especially for obese patients. KEY WORDS: AMIS, anteversion, inclination, hip joint, obesity, BMI, implantation, total joint replacement.

[Anterior cruciate ligament reconstruction -- long-term results evaluated clinically and by means of a rollimeter]. / Zhodnocení dlouhodobých výsledku operací náhrad LCA kolenního kloubu klinicky a pomocí rollimetru.

PURPOSE OF THE STUDY: Anterior cruciate ligament (ACL) reconstruction has recently become a widely used method of treating chronic instability. We have performed this operation in our department since 1996. The aim of this study was to evaluate the effect of this operation in a long-term perspective, using the rollimeter, a new device facilitating objective assessment of anterior stability of the knee. MATERIAL: Of 150 patients undergoing surgery for lesions of the anterior cruciate ligaments at the Department of Orthopedics for Children and Adults, 2nd Faculty of Medicine, Charles University and Motol Teaching Hospital, in the years 1996-2000, 42 were included in this study. Ligament reconstruction was performed by the transtibial technique using B-T-B patellar ligament graft; 90 % of the patients were treated by arthroscopy, 10 % by open surgery. METHODS: The patients operated on between 1996 and 2000 received a questionnaire and were invited to undergo examination at our outpatient department. The evaluation was based on the IKDC from, the results of Lachman's test performed on the rollimeter which permits objective assessment of the test, Tegner scores for assessment of daily activities and Lysholm scores for comparison of pre- and post-operative values. The results were statistically analyzed. Subjective evaluation was obtained from the questionnaires the patients submitted at this examination. RESULTS: The results show that, if the appropriate procedure is observed, the operation provides a reliable outcome by restoring knee joint stability and enabling the patient to return to previous sports activities. The new device rollimeter proved effective because of its simple construction and easy manipulation, and because the values obtained were more objective than those from clinical examination. The treated knee function evaluated on the basis of IKDC was normal or almost normal in 86 % of the patients. The objective measurement by the rollimeter of the anterior tibial translation showed a difference of up to 5 mm between the treated and the contralateral extremity. The average activity assessed according to Tergner increased by 3 grades and the average Lysholm scores improved by 30 points. A difference greater than 5 mm in anterior tibial translation between the treated and the contralateral extremity was considered as graft failure; this occurred in 7 % of the patients. The drawback of this operation, however, remains a restricted ability to kneel comfortably without pain and paresthesia in and around the tibial tuberosity. DISCUSSION: The first results of objective evaluation of ACL replacement show that a correctly performed operation results in a clear improvement in biomechanical properties of the knee joint. Our group of patients was evaluated by the established criteria and the results are in agreement with those reported in the relevant literature. In addition, the purpose of our study was to inform about the use of a new, simple measuring device that would be more easily available to hospitals in the Czech Republic than the KT 1000 arthrometer of western provenance. Both these devices, in contrast to other scoring systems, can provide objective assessment of post-operative outcomes and their broader application would contribute to a higher quality of retrospective evaluation of patient groups also in other hospitals. CONCLUSIONS: Our results are in agreement with those of published studies and give support to the fact that ACL reconstruction is a technically demanding operation whose results depend on strict observations of the surgical procedure and on the frequency of surgery carried out at individual institutions. Our study shows the possibility of a broader use of the rollimeter as an alternative to the KT 1000 arthrometer commonly used in other countries.