Knee injuries resulting in anterior cruciate ligament (ACL) tears are fairly common — especially in athletes and sports participants. With full tears, ACL reconstruction is usually required. And with so many people affected, this is a common subject of many research studies.
Most people (especially athletes) are concerned with how soon can they get back into action on the court or in the field. That’s one area of research interest. An equally important question is: how well does the new ACL hold up over time? Is osteoarthritis inevitable?
To address this question, a group of sports physical therapists and orthopedic surgeons performed a long-term (15-year) study of patients who had an ACL injury. Some of the patients had just the ACL tear. Others had additional damage done at the same time (e.g., meniscal injury, cartilage lesions, other ligament damage).
Everyone in both groups had an ACL reconstruction surgery. The goal of surgery was to restore stability and function of the knee joint. The graft used to replace the ruptured ACL was taken from the patellar tendon (just below the knee cap). This graft procedure is called a bone-patellar tendon bone (BPTB) autograft. Autograft means the graft tissue came from the patient’s own knee.
Results for these two groups were compared in terms of motion, function, strength, and activity level. Everyone was followed early on (six months after surgery, one year later, two years later) and then rechecked at 10 and 15 years after the procedure.
X-rays were used to document any signs of osteoarthritis. Narrowing of the joint space, presence of bone spurs, and deformity of the bones at the joint were evaluated to grade the severity of arthritic changes.
Knee function was improved and maintained for a long time after ACL reconstruction surgery.
The results of the study showed that improved knee function can be expected for patients with an isolated ACL injury as well as for those who have combined injuries.
However, osteoarthritis was common after these surgeries. Three-fourths of the patients (74 per cent) did have X-ray evidence of osteoarthritis. More patients in the combined injury group had osteoarthritis (and more severe arthritis) compared to the isolated ACL injury group.
The researchers concluded that ACL reconstruction surgery does not prevent osteoarthritis. Patients with isolated ACL injuries seemed to have mild arthritic changes. Patients with combined injuries were more likely to develop moderate to severe osteoarthritis. But not everyone with X-ray evidence of arthritis had symptoms.
It’s not clear why some people developed more arthritis than others and why some patients had pain with their arthritic changes and others didn’t. The next step in researching this topic is to look for risk factors for developing osteoarthritis. Discovering predictive factors of who will have arthritis might help surgeons find ways to prevent this natural progression of events.