A comparative study of arthroscopic reconstruction of anterior cruciate ligament by femoral tunnel positioning through the tendon incision technique and anteromedial technique

Chao FANG; Gang YU; Shuai LU; Yingming WANG; Qichun ZHAO

ABSTRACT

Objective:

To compare the short-term effect of the arthroscopic reconstruction of anterior cruciate ligament (ACL) by femoral tunnel positioning through the tendon incision (TI) technique and anteromedial (AM) technique.

Methods:

Between December 2015 and March 2017, 176 patients with ACL injuries underwent arthroscopic ACL reconstruction at the First Affiliated Hospital of USTC were analyzed. According to the method of localization of femoral tunnel, they were divided into two groups TI group (localization of femoral tunnel by TI for reconstruction of ACL) and AM group (localization of femoral tunnel by AM for reconstruction of ACL). There were 87 patients in the TI group (63 males and 24 females) with an age of 32.8±9.4 years (range, 19-51 years) and a body mass index (BMI) of 24.8±6.3 kg/m 2 (range, 18.1-31.7 kg/m 2), including 9 obese patients (BMI>28 kg/m 2). There were 89 patients in the AM group (59 males and 30 females) with an age of 36.7±13.0 years (range, 17-56 years) and a BMI of 25.7±5.8 kg/m 2 (range, 18.9-31.6 kg/m 2), including 11 obese patients. To evaluate whether the drill was in contact with the articular surface of the medial condyle of the femur, whether the anterior angle of the medial meniscus was damaged, the sagittal and coronal angles of the femoral tunnel and the total length of the femoral tunnel. The anterior drawer test, Lachmann test, pivot shift test, knee flexion angle (KFA), Lysholm score, International Knee Documentation Committee (IKDC) score and the incidence of postoperative complications were compared between the two groups. At the same time, the time of taking out tendon, operation time, hospital stay and recovery time were compared between two groups of obese people.

Results:

In the TI group, the guide pin could reach all areas of the medial wall of the lateral femoral condyle from the inferior cartilage edge to the top of the intercondylar fossa, the drill bit had no contact with the medial femoral condyle (MFC), and the anterior angle of the medial meniscus was not damaged. In AM Group, 3 cases of MFC and 1 case of anterior horn of medial meniscus were injured in order to get the best position of femoral tunnel. The angle of femoral tunnel in sagittal plane (50.2°±3.2°) and coronal plane (46.1°±5.8°) in experimental group was notably larger than that in control group (45.6°±5.4°, 38.3°±4.7°), the difference was statistically significant ( P<0.05). However, there was no significant difference in the length of femoral tunnel between the two groups (38.2±3.2 mm and 37.7±2.5 mm, P>0.05). All patients were followed up for an average of 8.3±2.1 (range, 3-12) months. The positive rates of anterior drawer test, Lachmann test and pivot shift test were not significantly different between the two groups at 3, 6, 9 and 12 months after operation ( P>0.05). The KFA, Lysholm and IKDC scores in both groups were significantly increased after operation ( P<0.05), but there was no significant difference of above indexes between the two groups ( P>0.05). The overall complication rate in AM group (14.6%, 13/89) was significantly higher than that in TI group (6.9%, 6/87), the difference was statistically significant ( P<0.05). Additionally, the tendon harvesting (15.0±0.2 min vs. 26.0±0.2 min, P<0.05) and operation time (2.0±0.3 h vs. 3.0±0.4 h, P<0.05) were significantly shortened among obese patients in experimental group compared with those in control group.

Conclusion:

The TI technique demonstrates comparable effectiveness to the AM technique in ACL reconstruction through femoral tunnel positioning, with the added advantage of safer femoral tunnel localization. This approach minimizes the risk of iatrogenic injuries to the articular cartilage of the medial condyle of the femur and the anterior horn of the medial meniscus. Furthermore, the TI technique reduces tendon removal time, particularly beneficial for obese patients.