Anterior cruciate ligament tears for the primary care sports physician: what to know on the field and in the office

Anterior Intercondylar Notch Geometry in Relation to the Native Anterior Cruciate Ligament Size

BACKGROUND

The intercondylar notch (ICN) and the anterior cruciate ligament (ACL) are important structures in knee morphometry, with key roles in stabilizing the knee.

AIM

To determine the associations between the specific shape of the ICN (A-, W-, or U-shape) and the ACL size in patients with intact ACLs.

METHODS

Magnetic resonance imaging (MRI) scans were independently analyzed by two experts: one orthopedic surgeon and one imaging physician. In all cases, the following measurements were taken based on the existing definitions: ACL area, anterior ICN (aICN) area, ICN width, lateral trochlear inclination (LTI), and Insall-Salvati index.

RESULTS

A total of 65 cases (50.8% male; 33.8 ± 10.2 years mean age at inclusion) were included in the study. The ACL and aICN areas were significantly larger in patients with U-shaped compared with A-shaped and W-shaped ICNs: 0.50 (0.20-0.80) vs. 0.40 (0.20-0.80) vs. 0.40 (0.30-0.80), p = 0.011 and 1.16 (0.57-3.60) vs. 0.47 (0.15-0.95) vs. 0.37 (0.15-0.81), p < 0.001, respectively. Internal meniscal lesions were more common in cases with U-shaped ICNs (64.0%), while external ones were more common in W-shaped ICN cases (35.3%). None of the A-shaped cases had external chondral or meniscal lesions. The ACL area was significantly larger in males and internal meniscal injuries, with no differences between chondral lesions, external meniscal injuries, patellar chondral lesions, patella alta, or trochlear dysplasia.

CONCLUSION

The specific shape of the intercondylar notch was associated with the anterior cruciate ligament-anterior intercondylar notch (ACL-aICN) area size correlation, with a strong correlation between ACL and aICN area when the intercondylar notch was A-shaped or W-shaped, and a low correlation when the notch was U- shaped. The specific shape of the intercondylar notch (A-, W-, or U-shape) was associated with the occurrence of both internal and external meniscal injuries, with the U-shaped intercondylar notch morphometry being more frequent in cases with internal meniscal injuries and the W-shape being more common in cases with external meniscal injuries.

Arthroscopic primary repair of the anterior cruciate ligament: what the radiologist needs to know

Recently, there has been a renewed interest in primary repair of proximal anterior cruciate ligament (ACL) tears. Magnetic resonance imaging (MRI) plays an important role in preoperative patient selection and in postoperative ligament assessment. Knowledge of the imaging factors that make patients candidates for primary ACL repair, namely proximal tear location and good tissue quality, can help radiologists provide information that is meaningful for surgical decision making. Furthermore, an understanding of the surgical techniques can prevent misinterpretation of the postoperative MRI. This article reviews preoperative MRI characterization of ACL injuries, techniques of arthroscopic primary ACL repair surgery and examples of postoperative MRI findings.

Primary anterior cruciate ligament reconstruction: perioperative considerations and complications

Anterior cruciate ligament (ACL) injuries are among the most commonly studied orthopaedic injuries. Despite having an excellent prognosis, complications do occur. The timely recognition and management of complications is imperative to ensure the success of reconstruction. Avoiding such complications requires thorough preoperative planning, proficient technical skills to properly manage intraoperative complications, and an extensive knowledge of possible postoperative complications.