Background: The anterior intermeniscal ligament (AIML) footprint and dimensions in skeletally immature knees have not been well documented. The AIML may play an important role in tibial spine fracture (TSF) reduction and meniscal repair/stability. The AIML is vulnerable to injuries during drill hole placement in anterior cruciate ligament (ACL) reconstruction. Therefore, it is necessary to characterize the anatomy of the AIML in skeletally immature knees to prevent iatrogenic injuries. Purpose: To evaluate AIML dimensions, its meniscal attachment patterns, and its relationship to the ACL. Study Design: Descriptive laboratory study. Methods: A total of 12 fresh-frozen cadaveric knees, 6 male and 6 female, were dissected (mean age, 9.8 years range, 9-11 years). The distal aspect of the quadriceps tendon was transected, and the joint capsule was opened. The infrapatellar fat pad was dissected and the AIML identified. Photographs were taken with an in-frame ruler, and the AIML length and distance to the anterior aspect of the ACL were measured. The AIML insertion type was determined according to the classification system reported by Nelson and LaPrade. Results: The mean length of the AIML was 23.6 mm (range, 19.8-31.9 mm). In 11 specimens, the mean distance between the AIML and the most anterior aspect of the ACL was 3.7 mm (range, 2.5-4.6 mm). In the remaining knee, the footprint of the anterior root of the medial meniscus, ACL, and AIML were nearly indistinguishable. The AIML was found with a type I insertion in 7 cases and a type II insertion in 5 cases. Conclusion: This study demonstrated the smaller dimensions of the AIML in skeletally immature patients and its relationship to key adjacent structures compared with previously reported adult data. These anatomic relationships highlight the AIML's vulnerability during ACL reconstruction, TSF reduction, and meniscal repair. Although the biomechanical consequences of the AIML remain unclear, we recommend avoiding injuries to this structure during procedures that may place it at risk. Clinical Relevance: This study characterized the anatomy of the AIML in pediatric knees, highlighting its consistent presence, smaller dimensions, and proximity to critical structures. Understanding the AIML's anatomy will help to minimize iatrogenic injuries during surgery, particularly in ACL reconstruction, TSF reduction, and meniscal repair.
Alayleh et al. (Sun,) studied this question.