Tesis

Pengaruh Variasi Sudut Pengeboran Outside-In Tunnel Femur Pada Rekonstruksi Ligamen Krusiatum Anterior Yang Dikombinasikan Dengan Tenodesis Ekstraartikular Lateral Teknik Lemaire Terhadap Insidensi Tunnel Collision: Studi Kadaver = Effect of Femoral Outside-In Tunnel Drilling Angle Variations in Anterior Cruciate Ligament Reconstruction Combined with Lateral Extra-articular Tenodesis Lemaire Technique on Tunnel Collision Incidence: A Cadaveric Study.

Latar Belakang : Teknik rekonstruksi ligamen krusiatum anterior (ACL) all-inside yang kian populer membuat metode outside-in untuk pembuatan tunnel femur semakin sering digunakan dalam bedah ACL. Pada rekonstruksi ACL yang dikombinasikan dengan tenodesis ekstraartikular lateral (LET), penempatan tunnel femoralis ACL secara outsidein berisiko menyebabkan tunnel collision dengan tunnel LET. Penelitian ini dilatarbelakangi oleh kebutuhan klinis untuk memahami pengaruh variasi sudut pengeboran outside-in terhadap insidensi tunnel collision pada prosedur kombinasi ACL+LET yang tengah berkembang. Penelitian ini bertujuan mengevaluasi apakah variasi sudut pengeboran femur secara outside-in memengaruhi insidensi terjadinya tunnel collision. Metode: Studi kadaverik dengan desain pengukuran berulang (repeated measures) pada 16 lutut kadaver. Setiap spesimen lutut menjalani rekonstruksi ACL anatomi (bundle tunggal) yang dikombinasikan dengan prosedur LET teknik Lemaire. Tunnel femur ACL dibuat secara arthroscopic outside-in pada sudut drilling 90°, 100°, dan 110° secara berurutan pada tiap spesimen, dengan lokasi footprint ACL yang konsisten. Sebuah tunnel femoral LET standar juga dibuat. Insidensi tunnel collision (terjadinya pertemuan/bertabrakannya jalur tunnel ACL dan LET) dievaluasi untuk masing-masing sudut melalui inspeksi langsung dan konfirmasi radiologis. Analisis statistik menggunakan uji Cochran’s Q untuk membandingkan perbedaan proporsi insidensi collision antar tiga sudut, dilanjutkan dengan uji berpasangan McNemar untuk mengetahui perbedaan antar sudut secara spesifik. Hasil : Variasi sudut pengeboran femur secara outside-in memengaruhi insidensi tunnel collision secara bermakna. Sudut 90° menunjukkan insidensi tunnel collision tertinggi, terjadi pada 75% (12/16) spesimen, terutama berupa tunnel convergence di korteks lateral femur. Pada sudut 100° dan 110°, insidensi tunnel collision menurun signifikan menjadi 31,3% (5/16) – tidak dijumpai lagi kasus tunnel convergence di korteks, melainkan intertunnel collision minimal yang terjadi di dalam tulang. Uji Cochran’s Q mengonfirmasi perbedaan proporsi insidensi collision yang signifikan di antara ketiga sudut (χ²=14,0; df=2; p < 0,001). Uji McNemar menunjukkan sudut 90° memiliki insidensi collision secara statistik lebih tinggi dibanding sudut 100° (p < 0,01) maupun 110° (p < 0,01). Tidak terdapat perbedaan signifikan antara sudut 100° dan 110° (p > 0,05). Kesimpulan: Sudut pengeboran femoral ACL rekonstruksi yang berbeda secara outsidein berdampak nyata terhadap risiko tunnel collision pada kombinasi ACL+LET. Pengeboran pada sudut 90° secara signifikan meningkatkan risiko benturan tunnel, sedangkan sudut lebih besar (100°–110°) menurunkan risiko tersebut secara drastis. Temuan kadaverik ini merekomendasikan sudut pengeboran minimal 100° (idealnya sekitar 110°) untuk teknik outside-in guna meminimalkan kemungkinan tunnel collision dalam rekonstruksi ACL dengan LET.
Kata Kunci: Rekonstruksi ACL, tenodesis ekstraartikular lateral, tunnel collision, outside-in drilling, sudut pengeboran femur


Background: The growing popularity of all-inside anterior cruciate ligament (ACL) reconstruction has led to more frequent use of the outside-in technique for femoral tunnel creation. In ACL reconstructions combined with a lateral extra-articular tenodesis (LET), drilling the femoral tunnel via an outside-in approach risks tunnel collision between the ACL and LET tunnels. This cadaveric study was motivated by the clinical need to address the rising incidence of such tunnel convergence/collision as combined ACL+LET procedures become more common. We aimed to determine whether varying the outsidein femoral drilling angle (90°, 100°, 110°) affects the incidence of tunnel collision in combined ACL reconstruction with LET. Methods: A cadaveric laboratory study with a repeated-measures design was conducted on 16 human cadaveric knees. Each specimen underwent an anatomic single-bundle ACL reconstruction combined with a standard LET (modified Lemaire technique). The ACL femoral tunnel was arthroscopically drilled using an outside-in guide at 90°, 100°, and 110° in the same knee (sequentially), targeting the native ACL footprint for each condition. A consistent femoral tunnel for the LET graft was also created. After each drilling configuration, the presence of a tunnel collision (any convergence or intersection of the ACL and LET tunnels) was assessed by direct inspection and confirmed with imaging. Statistical analysis was performed using Cochran’s Q test to compare collision incidence across the three angles, followed by paired McNemar tests to identify specific differences between angles. Results: The outside-in drilling angle had a significant effect on the incidence of tunnel collision. The 90° drilling angle yielded the highest collision rate, with 75% (12/16) of knees exhibiting a tunnel collision (predominantly as a direct tunnel convergence at the lateral cortex). In contrast, at 100° and 110° angles the collision incidence dropped markedly to 31.3% (5/16) of specimens. Notably, no cortical tunnel convergence occurred at 100° or 110°; any collisions at these angles were limited to minor intraosseous (within bone) tunnel intersections, and the majority of knees (68.7%) had no collision. Cochran’s Q analysis confirmed a significant difference in collision proportions among the three angles (χ²=14.0, df=2, p < 0.001). Pairwise McNemar tests indicated that 90° drilling led to a significantly higher collision incidence than 100° (p < 0.01) and 110° (p < 0.01). There was no statistical difference between the 100° and 110° conditions (p > 0.05). Conclusion: Varying the femoral tunnel drilling angle in an outside-in ACL reconstruction substantially influences the risk of tunnel collision when a LET is also performed. Drilling at a 90° angle significantly increases the likelihood of tunnels colliding, whereas more oblique angles of 100° and 110° greatly reduce this risk. From a technical standpoint, surgeons are advised to avoid horizontal (90°) femoral drilling in combined ACL+LET procedures and instead use angles of ≥100° (approximately 110° if feasible) to minimize the chance of tunnel collision.
Keywords: ACL reconstruction, lateral extra-articular tenodesis, tunnel collision, outside-in drilling, femoral drilling angle