The Internal Brace: Invention, Concept, and Impact on Ligament Repair

Who Invented the Internal Brace?

The internal brace surgical technique, a significant advancement in orthopedic ligament repair, was pioneered by Dr. Gordon Mackay, a Scottish orthopedic surgeon, who developed the concept of augmenting native tissue repair with a synthetic high-strength suture tape.

Understanding the Internal Brace Concept

The "internal brace" is a contemporary surgical technique designed to augment and protect primary ligament repairs, rather than replace them. It involves the use of a strong, synthetic suture tape (often made from materials like polyethylene, such as FiberTape) fixed to the bone on either side of a damaged ligament. This tape acts as an internal scaffold or "brace," providing immediate mechanical support to the healing ligament while allowing for early rehabilitation and reducing the risk of re-injury during the critical healing phase.

Key characteristics of the internal brace:

• Augmentation, not replacement: It supports the body's natural healing process for a damaged ligament, unlike traditional reconstruction which replaces the ligament entirely with a graft.
• Enhanced stability: Provides immediate biomechanical stability to the repaired ligament.
• Accelerated rehabilitation: The added stability often allows for a more aggressive and earlier return to activity compared to traditional repair methods.
• Preservation of native tissue: By supporting the original ligament, it aims to maintain its natural proprioception (sense of joint position) and biological function.

This technique is widely applied to various joints and ligaments, including the anterior cruciate ligament (ACL), medial collateral ligament (MCL), lateral ankle ligaments, Achilles tendon, and rotator cuff.

The Pioneer: Dr. Gordon Mackay

The conceptualization and initial development of the internal brace technique are attributed to Dr. Gordon Mackay, an orthopedic surgeon based in Scotland. Dr. Mackay's innovative work began with a focus on improving outcomes for anterior cruciate ligament (ACL) injuries.

Dr. Mackay's contributions include:

• Early ACL Repair: Historically, ACL tears were often treated with reconstruction using a graft (from the patient or a donor). Dr. Mackay championed the idea of repairing the native ACL when feasible, particularly in proximal tears where the ligament had detached from the femur.
• Ligament Augmentation and Reconstruction System (LARS): While not identical to the internal brace, Dr. Mackay's earlier work with the LARS system (a synthetic ligament replacement) laid some groundwork for thinking about synthetic augmentation. The internal brace evolved from a desire to support native tissue repair rather than solely replace it.
• Introduction of Suture Tape Augmentation: His pivotal contribution was demonstrating the efficacy of using a high-strength suture tape, fixed to the bone, to protect and reinforce the primary repair of the native ACL. This approach provided the necessary support to allow the torn ligament ends to heal biologically, a concept that was revolutionary at the time.

His work, particularly with ACL repair, showed that by providing a "seatbelt" for the healing ligament, patients could achieve better outcomes, preserve their native anatomy, and potentially return to activity sooner.

Evolution and Clinical Adoption

Following Dr. Mackay's pioneering efforts, the internal brace concept gained significant traction within the orthopedic community. While the core principle remained consistent, specific techniques and materials have been refined and popularized by various surgeons and medical device companies.

Key aspects of its adoption and evolution:

• Material Advancements: The development of robust, biocompatible suture tapes (such as Arthrex's FiberTape, which became synonymous with the technique for many) played a crucial role in its widespread adoption.
• Expansion to Other Joints: The success seen in ACL repair led to the application of the internal brace technique in other areas, including:
  • Medial Collateral Ligament (MCL) Repair: Especially useful for severe MCL injuries.
  • Lateral Ankle Ligament Repair: Enhancing primary repairs of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL).
  • Achilles Tendon Repair: Providing additional strength and protection for Achilles tendon repairs.
  • Rotator Cuff Repair: Augmenting repairs in the shoulder to reduce re-tear rates.
• Growing Evidence Base: Numerous clinical studies have emerged, supporting the biomechanical advantages and positive clinical outcomes associated with internal brace augmentation, particularly in terms of early recovery and reduced re-injury rates.

It's important to note that while Dr. Mackay invented the concept and technique, the term "Internal Brace" itself is a registered trademark of Arthrex, Inc., which has been instrumental in popularizing and standardizing specific instrumentation and suture tapes for the procedure.

The Science Behind the Internal Brace

The effectiveness of the internal brace technique is rooted in fundamental biomechanical and biological principles:

• Load Sharing: The suture tape shares the load with the healing ligament, reducing stress on the delicate repair site. This protection prevents excessive strain that could disrupt the healing process.
• Scaffold for Healing: While not a biological scaffold in the traditional sense, the stable environment created by the internal brace allows the body's natural healing mechanisms to proceed more effectively, encouraging collagen synthesis and tissue remodeling.
• Enhanced Stability: By providing immediate, robust stability, the internal brace mitigates micromotion at the repair site, which can be detrimental to healing. This stability also facilitates earlier, more aggressive rehabilitation.
• Preservation of Proprioception: Unlike reconstruction which replaces the ligament, the internal brace supports the native ligament, thereby preserving its mechanoreceptors which are crucial for proprioception and neuromuscular control of the joint.

Broader Impact and Future Directions

The internal brace represents a significant paradigm shift in orthopedic surgery, moving towards preserving native anatomy and enhancing biological healing whenever possible. It has provided surgeons with an additional tool, particularly for certain types of ligament injuries that were previously challenging to treat optimally with either traditional repair or reconstruction alone.

Its impact includes:

• Reduced Morbidity: By avoiding the need for a graft harvest (as in autograft reconstruction), it can reduce donor site pain and complications.
• Faster Recovery: Patients can often begin rehabilitation earlier and potentially return to activities more quickly.
• Improved Outcomes: For specific indications, it offers outcomes comparable to, or in some cases superior to, traditional methods, particularly in terms of retaining native tissue function.

Ongoing research continues to explore new applications, refine surgical techniques, and develop even more advanced materials to further enhance the efficacy and expand the indications for internal brace technology.

Conclusion: A Paradigm Shift in Ligament Repair

The internal brace technique, developed by Dr. Gordon Mackay, stands as a testament to innovation in orthopedic surgery. His pioneering vision to augment rather than solely replace damaged ligaments has transformed the approach to treating various musculoskeletal injuries. By providing crucial mechanical support to healing native tissues, the internal brace has enabled faster rehabilitation, preserved vital proprioceptive function, and ultimately improved outcomes for countless patients, marking a true paradigm shift in the field of ligament repair.