When surgeons are reconstructing the anterior cruciate ligament (ACL) of the knee, they often see damage to the joint surface. The area affected is called the articular cartilage. This is the cartilage that covers the joint and makes it possible for the two sides of the joint to slide and glide smoothly across each other.
There is a question about whether or not surgeons should go ahead and repair these cartilage (chondral) lesions. Does it make a difference in the results of the ACL repair? Maybe it doesn’t matter and it’s best to leave these defects alone. We just don’t know yet which approach is best.
In this study, surgeons compared results between two groups of ACL patients: those with a chondral defect and those without. The patients with just an ACL rupture but no chondral damage were considered the control group. Patients in the two groups were matched by age, sex, and type of chondral injury. In terms of the cartilage injury, each patient had one defect rated as a grade 3 or 4 — that’s moderate-to-severe.
Everyone in both groups was treated the same way. First they saw a physical therapist for a preoperative program of rehabilitation. Then, the surgeon reconstructed the ruptured ligament using a bone-tendon-bone graft. This means they took a piece of tendon from some other area of the leg and used it to replace the damaged ACL. Then everyone went back to rehab after surgery. They all completed the same program of exercises. The cartilage lesion was not repaired and no special measures were taken to rehab differently because of the chondral lesion.
Everyone was followed for 10 to 15 years to see what the long-term differences might be between the two groups. The authors were unable to see a measurable difference between the two groups. The location of the lesion didn’t seem to change anyones’ function after surgery.
X-ray findings weren’t significantly different between the two groups. And tests of function using the International Knee Documentation Committee (IKDC) scores showed no major differences from one group to the other.
The authors remind us that there are still many unanswered questions about cartilage injuries. They don’t heal well and we don’t have very good treatments yet to encourage proper healing. The size of the defect doesn’t seem to make a difference either. The long-term effects are the same in patients with mild versus severe injuries.
The location within the joint articular cartilage doesn’t seem to matter either. Most of the lesions occur on the femoral condyle (bottom knob of the femur or thigh bone). But even when the lesions occurred on other locations, the results weren’t any different than for patients with femoral lesions.
Differences in knee score on the IKDC didn’t show up based on location of the chondral lesions. X-rays didn’t really show any signs of knee joint degeneration but this may be because of the young age of the patients and the fact that signs of joint degeneration don’t appear until there is quite a bit of damage.
Sometimes patients had to have another surgery after the ACL repair. There were different reasons for this such as loose fragments of bone or cartilage in the joint space, development of osteoarthritis, or continued joint misalignment. But the presence of the initial chondral lesion didn’t seem to be a factor in that.
Likewise, when patients complained of knee pain, stiffness, and giving way of the joint, patients in both groups were affected equally. So those chronic symptoms weren’t necessarily because they had a cartilage injury in addition to the ACL injury.
They concluded that deep cartilage defects that occur along with ACL rupture can be left alone. Treating them or not treating them does not give better results. And these lesions don’t seem to contribute to further joint damage or degeneration.
The authors would like to see more studies in this area before throwing the towel in on chondral lesions. It’s possible that some other (as yet unidentified) factor is important in the treatment decision about chondral lesions. Perhaps if we found a better way to treat the chondral lesions, the results would be improved.