The treatment of combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries has evolved significantly over the decades, moving from extensive open surgeries with high rates of stiffness to more nuanced approaches that prioritize both ligament healing and knee function. While historical practices often involved extensive open procedures, modern orthopedic surgeons now have a wider range of operative and nonoperative options at their disposal, informed by advances in imaging, surgical techniques, and a deeper understanding of ligament biomechanics.
A Historical Shift in Approach
In the 1970s and 1980s, combined ACL and grade 3 MCL injuries were typically addressed with large, open surgical procedures. “It was terrible,” recalls Andy Williams, MBBS, FRCS(Ortho), FFSEM(UK), a consultant knee surgeon at Fortius Clinic in London. “Because we did not understand the anatomy, we cobbled it all together and, the structures we had repaired were not at the right length. You tended to end up with a knee that would not straighten and would not bend, but the MCL remained loose. It was the worst of all worlds.”
The advent of magnetic resonance imaging (MRI) proved pivotal in changing this approach. As Gregory S. DiFelice, MD, an orthopedic surgeon at Hospital for Special Surgery, explains, “MRI allowed us to see not only if the ligament was torn, but also how the ligament was torn.” Prior to MRI, surgeons relied on open exploration to assess the extent of ligament damage. The introduction of arthroscopy further refined surgical capabilities, enabling less invasive procedures and more precise assessment of the knee’s internal structures.
By the 1990s, the recognition of post-operative stiffness associated with open procedures led to a shift towards nonoperative management of the MCL. “It became clear that it would be better not to touch the MCL,” Williams stated. “The dogma was to treat in a brace for 6 weeks, with or without the ACL injury, and then you would go to surgery from 6 weeks for the ACL. That held sway for a long time, and that led to the notion that the MCL takes care of itself.”
Modern Considerations and the Rise of Acute Treatment
Today, the management of combined ACL and MCL injuries is more complex and individualized. Jelle P. Van der List, MD, PhD, MBA, a clinical assistant professor of orthopedic surgery at The Ohio State University Wexner Medical Center, notes that a systematic review published in Arthroscopy highlighted limitations of both nonoperative and delayed surgical approaches. Nonoperative treatment can result in persistent valgus laxity, potentially increasing the risk of ACL graft failure, while delayed ACL reconstruction prolongs rehabilitation and leaves the knee unstable for an extended period.
Recent advancements have prompted a growing interest in acute simultaneous surgical treatment of both ligaments when appropriate. DiFelice explains that patients with significant laxity in both the ACL and MCL may benefit from a repair procedure addressing both structures. A retrospective analysis conducted by DiFelice and colleagues demonstrated that 90% of patients with a grade 3 superficial MCL injury combined with cruciate or bicruciate ligament injury, who underwent acute MCL repair and early range of motion rehabilitation, achieved negative valgus laxity stress testing and experienced low rates of reoperation due to stiffness.
However, surgeons emphasize the importance of “sensible” treatment decisions. Williams advocates for a cautious approach, suggesting a bracing period of 4 to 6 weeks for most combined ACL-MCL injuries, followed by reassessment and surgical intervention for the ACL, with MCL surgery considered if grade 2 or 3 valgus laxity or a positive dial or Slocum test is present. He notes that professional athletes may require a more aggressive, immediate approach due to the high demands of their sport.
The Role of Tear Location and Augmentation
The location of the MCL tear is a critical factor in treatment planning. R. Alexander Creighton, MD, Yeargan Professor and chief of sports medicine at UNC Orthopedics, points out that proximal injuries may heal more effectively than distal injuries. Distal MCL injuries, particularly those with a Stener-like lesion (displacement of the MCL superficial to the Pes Anserine hamstring tendons), often require more aggressive surgical intervention as they are unlikely to heal spontaneously.
The timing of surgery is also crucial. Van der List’s research indicates that earlier ACL reconstruction is associated with a decreased risk of long-term osteoarthritis, with the greatest benefit observed when surgery is performed within 6 to 12 months of injury. He emphasizes that addressing the ACL acutely can create a more favorable environment for MCL healing, potentially allowing for nonoperative management of the MCL in some cases.
Some surgeons are incorporating biologic augmentation techniques, using collagen-based implants, suture augmentation, or grafts to enhance ligament repair. However, van der List suggests that the optimal indications for these techniques remain unclear, and more research is needed to determine their effectiveness.
Future Directions
Matthew T. Provencher, MD, MBA, professor of orthopedics at The Steadman Clinic, highlights the need for larger, multicenter studies to further refine treatment protocols and improve patient outcomes. He emphasizes the importance of understanding the interplay between the ACL and MCL and optimizing surgical techniques to restore knee stability and function. The goal is to provide patients with the best possible care, minimizing complications and maximizing their return to activity.
