The Importance of Tibial Tunnel Placement in Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction.
ABSTRACT PURPOSE: The purposes of this study were to measure the anterior edge of the tibial tunnel after anatomic anterior cruciate ligament (ACL) reconstruction on lateral radiographs and to determine whether the difference in tibial tunnel placement affects postoperative outcomes. METHODS: For 60 patients who underwent anatomic double-bundle ACL reconstruction with semitendinosus tendon, we evaluated the side-to-side difference in anterior tibial translation on stress radiographs, as well as rotational stability by the pivot-shift test, 2 years after surgery. Loss of extension (LOE) was evaluated on lateral radiographs of both knees in full extension, and graft integrity was assessed during second-look arthroscopy 1 to 2 years after surgery. On true lateral radiographs, we measured the anterior placement percentage of the tibial tunnel using the method described by Amis and Jakob. The cutoff value was set at 25% of the mean value of the anterior edge of the ACL that Amis and Jakob reported, and patients were divided into 2 groups (27 in the anterior group and 33 in the posterior group). Postoperative clinical results were compared between the groups. RESULTS: The mean anterior placement percentage was 26.0% ± 4.1%. The postoperative mean side-to-side difference was 1.4 ± 2.7 mm for the anterior group and 3.0 ± 2.7 mm for the posterior group, a significant difference (P < .05). The positive ratio of the pivot-shift test was not significantly different between groups (P > .05). Mean LOE in the anterior and posterior groups was 0.9° ± 3.0° and -0.8° ± 4.0°, respectively; the difference was not significant (P > .05). Five of 27 knees in the anterior group and 5 of 33 knees in the posterior group had superficial graft laceration or elongation, which was not significantly different (P > .05). CONCLUSIONS: Anterior placement of the tibial tunnel in anatomic double-bundle ACL reconstruction leads to better anterior knee stability than posterior placement does. Anterior tibial tunnel placement inside the footprint did not increase the incidence of LOE and graft failure. LEVEL OF EVIDENCE: Level IV, therapeutic case series.
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ABSTRACT: Purpose The purpose of the study reported here was to find out if the clinical and magnetic resonance imaging (MRI) findings of a reconstructed anterior cruciate ligament (ACL) have an association. Our hypothesis, which was based on the different functions of the ACL bundles, was that the visibility of the anteromedial graft would have an impact on anteroposterior stability, and the visibility of the posterolateral graft on rotational stability of the knee. Methods This study is a level II, prospective clinical and MRI study (NCT02000258). The study involved 75 patients. One experienced orthopedic surgeon performed all double-bundle ACL reconstructions. Two independent examiners made the clinical examinations at 2-year follow-up: clinical examination of the knee; KT-1000, International Knee Documentation Committee and Lysholm knee evaluation scores; and International Knee Documentation Committee functional score. The MRI evaluations were made by two musculoskeletal radiologists separately, and the means of these measurements were used. Results We found that the location of the graft in the tibia had an impact on the MRI visibility of the graft at 2-year follow-up. There were significantly more partially or totally invisible grafts if the insertion of the graft was more anterior in the tibia. No association was found between the clinical results and the graft locations. Conclusion Anterior graft location in the tibia can cause graft invisibility in the MRI 2 years after ACL reconstruction, but this has no effect on the clinical recovery of the patient.Open Access Journal of Sports Medicine 08/2014; 5:197-203. DOI:10.2147/OAJSM.S62050
Article: What's New in Sports MedicineThe Journal of Bone and Joint Surgery 04/2014; 96(8):695-702. DOI:10.2106/JBJS.M.01569 · 5.28 Impact Factor
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ABSTRACT: BACKGROUND:Although the importance of tibial tunnel position for achieving stability after anterior cruciate ligament (ACL) reconstruction was recently recognized, there are fewer detailed reports of the anatomy of the tibial topographic footprint compared with the femoral side. HYPOTHESIS:The ACL tibial footprint has a relationship to bony prominences and surrounding bony landmarks. STUDY DESIGN:Descriptive laboratory study. METHODS:This study consisted of 2 anatomic procedures for the identification of bony prominences that correspond to the ACL tibial footprint and 3 surrounding landmarks: the anterior ridge, lateral groove, and intertubercular fossa. In the first procedure, after computed tomography (CT) was performed on 12 paired, embalmed cadaveric knees, 12 knees were visually observed, while their contralateral knees were histologically observed. Comparisons were made between macroscopic and microscopic findings and 3-dimensional (3D) CT images of these bony landmarks. In the second procedure, the shape of the bony prominence and incidence of their bony landmarks were evaluated from the preoperative CT data of 60 knee joints. RESULTS:In the first procedure, we were able to confirm a bony prominence and all 3 surrounding landmarks by CT in all cases. Visual evaluation confirmed a small bony eminence at the anterior boundary of the ACL. The lateral groove was not confirmed macroscopically. The ACL was not attached to the lateral intercondylar tubercle, ACL tibial ridge, and intertubercular space at the posterior boundary. Histological evaluation confirmed that the anterior ridge and lateral groove were positioned at the anterior and lateral boundaries, respectively. There was no ligament tissue on the intercondylar space corresponding to the intercondylar fossa. In the second investigation, the bony prominence showed 2 morphological patterns: an oval type (58.3%) and a triangular type (41.6%). The 3 bony landmarks, including the anterior ridge, lateral groove, and intertubercular fossa, existed in 96.6%, 100.0%, and 96.6% of the cases, respectively. CONCLUSION:There is a bony prominence corresponding to the ACL footprint and bony landmarks on the anterior, posterior, and lateral boundaries. CLINICAL RELEVANCE:The study results may help create an accurate and reproducible tunnel, which is essential for successful ACL reconstruction surgery.The American Journal of Sports Medicine 04/2014; 42(6). DOI:10.1177/0363546514528789 · 4.36 Impact Factor