Overview of ACL Surgery and Osteoarthritis in the Knee
ACL reconstructions are among the most common orthopaedic procedures performed in the United States. However, despite surgery intended to stabilize the joint, individuals who undergo an ACL reconstruction have a 3 to 5 times greater risk of developing posttraumatic arthritis of the knee. Thus, it is important to develop early and effective interventions to prevent posttraumatic arthritis after ACL surgery for this population. In our hands, we try to address this by having patients initiate physical therapy immediately after surgery in an effort to restore their quadriceps function. It has been documented that a restoration of quadriceps function improves overall joint absorption and may lead to a slowdown of progression of arthritis after injury.
One of the important things to recognize about posttraumatic arthritis, compared to age-related degenerative arthritis is that there is a discrete episode known at the time of the injury. Since the starting point of this injury is known, early therapeutic intervention may be possible in the future to slow down the biologic responses that lead to the progression of posttraumatic arthritis.
Articular cartilage injury after an impaction force, which is most commonly seen with an ACL tear, has been widely documented. The presence of blood in the joint and the resultant inflammatory process that occur after a traumatic joint injury is well known. There are numerous inflammatory degenerative cytokines, activated macrophages, and other degenerative products which can lead to early chondrocyte death, chondrocyte loss over time, and ultimately osteoarthritis progression these patients.
Osteoarthritis in the Knee
Osteoarthritis has been ranked number 5 in the top 10 most costly medical conditions after heart disease, cancer, mental and trauma related disorders with an estimated cost burden of $185.5 billion in the USA. According to the American Academy of Orthopaedic Surgeons, every year 9 million adults in the United States are diagnosed with arthritis and 600,000 total joint replacements are performed. It is recognized that over time, osteoarthritis of the knee occurs in 50% to 60% of patients following a joint injury. This is because cartilage cells have a very low capacity to regenerate damaged cartilage tissue after injury. Today, all of our cartilage restoration procedures do not restore the cartilage back to normal unless there is a fresh osteoarticular allograft procedure performed.