Transtibial Versus Anteromedial Portal Technique for Femoral Tunnel Drilling in Primary Single-Bundle Anterior Cruciate Ligament Reconstruction: A Meta-analysis of Level 1 and 2 Evidence of Clinical, Revision, and Radiological Outcomes

Abstract

Background: Although numerous clinical studies have compared transtibial (TT) and anteromedial portal (AMP) drilling of femoral tunnels during anterior cruciate ligament reconstruction (ACLR), there is no high-quality, evidence-based consensus regarding which technique affords the best outcome. Hypothesis: There would be no difference between the TT and AMP techniques in terms of knee stability, patient-reported outcomes, incidence of revision, and radiological results. Study Design: Meta-analysis; Level of evidence, 2. Methods: The PubMed and EMBASE databases were searched from inception to February 1, 2021. Level 1 and 2 clinical trials that compared TT and AM techniques were included. Data were meta-analyzed for the outcome measures of knee stability, patient-reported functional outcomes, incidence of revision, and radiological results. Dichotomous variables were presented as odds ratios (ORs), and continuous variables were presented as mean differences (MDs) and standard mean differences (SMDs). Results: The meta-analysis included 18 clinical studies, level of evidence 1 or 2, that involved 53,888 patients. Pooled data showed that the AMP group had a lower side-to-side difference (SMD, 0.22; 95% CI, 0.06 to 0.39; P = .009), a lower incidence of pivot-shift phenomenon (OR, 3.69; 95% CI, 1.26 to 10.79; P = .02), and a higher postoperative Lysholm score (SMD, −0.26; 95% CI, −0.44 to −0.08; P = .005) than the TT group. However, no statistically significant differences were seen in other outcomes, including subjective International Knee Documentation Committee scores (SMD, –0.11; 95% CI, –0.30 to 0.09; P = .30) or grades (OR, 0.93; 95% CI, 0.35 to 2.49; P = .89), postoperative activity level (MD, –0.14; 95% CI, –0.42 to 0.15; P = .35), and incidence of revision ACLR (OR, 1.04; 95% CI, 0.93 to 1.16; P = .45). The TT technique was more likely to create longer (SMD, 1.05; 95% CI, 0.05 to 2.06; P = .04) and more oblique (SMD, 0.81; 95% CI, 0.51 to 1.11; P < .001) femoral tunnels than the AMP technique, and a higher height ratio of the aperture position was detected with the TT technique (SMD, −3.51; 95% CI, −5.54 to −1.49; P < .001). Conclusion: The AMP technique for ACLR may be more likely to produce better knee stability and improved clinical outcomes than the TT technique, but no difference was found in the incidence of revision between the 2 groups.

Satisfactory 5‐year functional outcomes following primary ACL reconstructions from the UK National Ligament Registry

“…The anteromedial portal (AM) was the most preferred approach for femoral tunnel drilling in the NLR (73%), while the trans‐tibial technique (TT) was the least common technique (6%) and appeared to be gradually falling out of favour among UK surgeons. This is supported by the recent literature that shows that AM portal and retrograde drilling techniques allow for more anatomic positioning of the femoral tunnel when compared with the transtibial technique [41–44].…”

Clinical Outcomes of a Novel Hybrid Transtibial Technique for Femoral Tunnel Drilling in Anterior Cruciate Ligament Reconstruction: A Large Single-Center Case Series With a Minimum 2-Year Follow-up

“…Previous studies have directly compared the outcomes after ACLR using the TT versus AMP technique; however, there is no clear consensus as to which technique provides the best outcome postoperatively. 15,22,23 Recent literature has provided supporting evidence highlighting the importance of replicating the native footprint of the ACL via anatomic positioning of the femoral tunnel, thus popularizing the AMP technique over the conventional TT approach. 22,38,40 However, despite the improved anatomic placement of the ACL graft when using the AMP technique, 33 a unique set of technical challenges associated with this approach has emerged such as the need to hyperflex the knee, a shorter tunnel length, the risk of injuring medial femoral condylar articular cartilage, and/or posterior wall blowout.…”

Ten Pearls for Anterior Cruciate Ligament Reconstruction

“…There are a number of techniques to confirm satisfactory placement of the femoral tunnel. 18 , 19 , 20 , 21 , 22 An offset inside-out guide can be used to position the tunnel anterior to the posterior margin of the femoral condyle ( Fig 2 ). 23 , 24 Other inside-out guides are available without a set offset guide that allow for more flexibility in tunnel placement.…”