PURPOSE OF THE STUDYThe aim of the study is to present a comparison of short-term results of double-versus single-bundle anatomical reconstruction of the anterior cruciate ligament (ACL) using hamstring endons and their fixation with absorbable interference screws. MATERIAL AnD METHODSA total of 110 patients with an isolated ACL lesion and the healthy contralateral knee who met the indication criteria for ACL double bundle reconstruction (TISL, 14 mm; ICnW, 12 mm) were intra-operatively allocated at random to either double-bundle group (DB, n=55) or single-bundle group (SB, n=55). At 12 months after surgery, 97 patients (DB group, n=49; SB group, n=48), comprising 68 men and 29 women, were evaluated; the average age was 29.1 years and the injury-to-surgery interval was 15.9 weeks. Pre-and post-operative subjective criteria involved the IKDC and Lysholm score. Objectively, the occurrence of graft failure, range of motion deficit, return to pre-injury sports activity, side-to-side difference in anterior laxity of both knees in 20° flexion on a GnRB laximeter at an applied pressure of 124 n and 250 n, and pivot shift phenomenon were assessed. RESULTSno statistically significant difference was found in pre-operative values between the two groups. Post-operatively, there were no significant differences in the occurrence of complete graft failure (p=0.0755; DB group, n=0; SB group, n=3), rangeof-motion deficit (p=0.2277-0.9788) or return to pre-operative sports activity (p=0.2322). In the DB group, side-to-side anterior tibial shifts at a pressure of 124 n (medians=1.3 mm and 2.1 mm for DB and SB groups, respectively; p=0.0007) and at a pressure of 250 n (DB group =2.1 mm; SB group = 3.1 mm; p<0.0001) were significantly different from the corresponding values in the SB group. Positive results for the pivot shift test (PST) were significantly less frequent in the DB than the SB group (Chi-square test =0.0112). The SB group patients had a 2.9-times (odds ratio, 2.8704) higher risk of positive postoperative PST results than the DB group patients. In both groups, a comparison of pre-and post-operative criteria showed significant improvement in both the subjective and the objective results. DISCUSSIOnThe results of this study, in accordance with other authors' conclusions, suggest that the double-bundle technique provides better control over rotational and anterior knee laxity and therefore restores knee biomechanics better. However, other literature data do not confirm any significantly better outcomes of this method. Since only short-term results have been obtained so far, the study will continue because only the long-term results can provide conclusive evidence of an advantage of one technique over the other. COnCLUSIOnSOur study showed significantly better restoration of knee rotational and anterior laxity in the patients undergoing anatomical reconstruction of the ACL by the double-bundle technique. The other evaluated criteria did not differ in relation to the technique used.

PURPOSE OF THE STUDYThe purpose of the prospective randomised study was to assess the benefits of the platelet-rich fibrin (PRF) application during the anatomic anterior cruciate ligament reconstruction (ACLR) for tendon graft healing. MATERIAL AND METHODSThe study included 40 patients with an isolated rupture of the anterior cruciate ligament in the knee. The MRI findings on the tendon graft were evaluated at 6 months and 12 months after the surgery in a total of 33 patients, namely in 10 women/23 men (21 right knee/12 left knee), with the mean age of 29.1 years and at the mean follow-up of 15.9 weeks after the injury. The randomisation using envelopes was carried out at the beginning of arthroscopy either in the group with the PRF application (Group 1) (17 patients) or in the group without the PRF application (Group 2) (16 patients). The followed-up patients underwent the ACLR with targeting the femoral tunnel through anteromedial portal using the autografts of m. semitendinosus and m. gracilis with Tightrope femoral fixation and Inion implant in tibia. In Group 1, during the surgery PRF was applied both in the drilled tunnels (intraosseously) and directly to the surface of the tendon graft itself (intraarticular part). The Group 2 was a control group in which the same intervention was performed, however without the PRF application. In the 6 th and 12 th month after the surgery, the signal intensity of the knee and occurrence of the ACL graft failure, bone (marrow) oedema rate near the tunnels were assessed by an independent radiologist using a 3 Tesla MRI. RESULTSIn the 6 th and also in the 12 th postoperative month, neither a complete, nor a partial graft failure was found in the group with PRF, whereas in Group 2 a complete or a partial graft failure was observed in 12.5% (p = 0.23). In the 6 th month, a bone marrow oedema near the intraosseous parts of the graft was reported in 94.1% of patients in Group 1 and in 81.3% of patients in Group 2, while in the 12 th month it was 23.5% of evaluated patients in Group 1 and 37.5% patients in Group 2. The differences between the two groups were not statistically significant in the 6 th (p = 0.096) or in the 12 th month (p = 0.43). In the 6 th month, a fully ligamentised graft was found in 52.9% of patients in Group 1 and in 37.5% of patients in Group 2 (p = 0.061), a partially ligamentised graft was present in 47.1% of patients in Group 1 and in 50% of patients in Group 2. In the 12 th month, a fully ligamentised graft was seen in 94.1% of patients in Group 1 and in 75% of patients in Group 2 (p = 0.26) and a partially ligamentised graft was present in 5.9% of patients in Group 1 and in 12.5% of patients in Group 2. In the remaining 12.5% of patients in Group 2, the finding was assessed as a graft with no signs of ligamentisation. DISCUSSIONWe have not encountered a paper in the Czech or world literature which would present results of a similar study, i.e. which would evaluate the potential benefits of the platelet-rich fibrin application in the course of the anatom...