Understand how a chondral lesion of the lateral femoral condyle relates to ACL injuries and why it matters in surgical assessment.
This article is based on the findings of a clinical study titled Lateral femoral chondral lesions are more frequent when an anterior cruciate ligament tear is concomitant with a lateral femoral notch sign, but do not progress over time, published in Orthopaedics & Traumatology: Surgery & Research (2024).
To explore further, you can read more of Professor Étienne Cavaignac’s published studies available on his website.
In the broader context of anterior cruciate ligament injuries, lateral femoral condyle chondral lesions (damage to the cartilage covering the bones in the knee) are a frequent but under-explored complication. These lesions can negatively affect joint function and long-term outcomes if not correctly identified and monitored.
The presence of the lateral femoral notch sign (LFNS) has been long associated with acute anterior cruciate ligament (ACL) ruptures. It appears as an impression fracture on the lateral femoral condyle caused by tibial impact during a pivot shift injury. This radiological sign is observed in 25% to 33% of ACL-injured patients and is considered a reliable diagnostic indicator.
This study sheds light on the correlation between LFNS and cartilage damage in the lateral femoral condyle, a subject that had remained largely speculative due to a lack of prospective imaging data.
According to the research findings, the presence of a lateral femoral notch sign significantly increases the likelihood of a chondral lesion one year after ACL reconstruction. In the study, 37% of patients with a preoperative LFNS showed signs of cartilage damage versus only 13% in the group without LFNS.
However, when statistical adjustments were made to account for pre-existing cartilage injuries prior to surgery, the direct association between LFNS and new lesions diminished. This indicates that the chondral damage is already present at the time of the initial trauma and does not worsen over time.
In practical terms, the LFNS should be seen as a marker of preexisting damage, not as a predictor of progressive cartilage deterioration.
All patients underwent MRI imaging both before and one year after surgery. Chondral lesions were classified using the Outerbridge scale, a gold standard in cartilage grading. The size of the lateral femoral notch was also measured, with a threshold of 1.8 mm used to determine positivity.
Interestingly, patients with no cartilage damage one-year post-surgery had a significantly smaller LFNS at baseline than those who developed a lesion (2.30 mm vs 3.10 mm on average).
One of the secondary aims of the study was to assess bone bruises and clinical outcomes. These bruises were also visible on MRI but did not show a statistical difference between patients with or without LFNS at one year. In both groups, bruising was largely resolved by the time of the follow-up imaging.
When it comes to functional recovery, all patients showed similar outcomes. IKDC, Lysholm, and Tegner scores were comparable across both groups, indicating that the presence of LFNS and associated cartilage injuries did not impact clinical performance or rehabilitation one year after ACL surgery.
These results are reassuring for both patients and clinicians, suggesting that although structural damage may be present, it does not hinder functional recovery when appropriately managed.
The study concludes that the lateral femoral notch sign is not an indication for additional surgical intervention. Although some case reports advocate treating deep notch injuries with osteosynthesis or staged procedures, this research supports a conservative approach.
The LFNS remained visible in 70% of cases one year after surgery but decreased in size, suggesting partial remodeling without clinical consequence.
From a surgical standpoint, the presence of LFNS should be used to identify patients at higher risk of chondral damage, rather than to justify additional procedures. Surgeons can instead focus on optimal ACL reconstruction and follow-up.
Patients with a lateral femoral notch sign are more likely to exhibit cartilage damage in the knee following an ACL rupture, but this damage remains stable over time and does not impair clinical recovery. The LFNS should therefore be interpreted as a marker of initial injury severity, not of long-term deterioration.
For further insight into cartilage injuries and ACL-related pathology, we recommend reading more clinical studies led by Professor Etienne Cavaignac.
We also highly recommend consulting Professor Cavaignac for expert guidance on knee trauma and ligament reconstruction.
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