Injuries severe enough to tear the anterior cruciate ligament in the knee often require surgery to repair or reconstruct the ligament. The timing of surgery remains under consideration. Should surgery be done right away? Does it matter how long someone waits before having the torn ligament reconstructed? What about this: does early surgery prevent meniscal tears and joint cartilage injuries? And conversely, does delaying surgery increase the risk of meniscal tears and joint cartilage injuries?
In this study, data from the Norwegian Knee Ligament Registry (NKLR) is used to answer these questions. In Norway, orthopedic surgeons send patient information to a central database on all patients having ACL surgery. Age, gender, date of injury, and date of surgery are recorded. The location and severity of any other injuries are also reported.
Almost 3500 patients were included in the study. All had ACL reconstructive surgery performed in Norway between 2004 and 2006. The time from injury to surgery varied from nine days to 40 years. Most of the patients had surgery within the first year after injury.
The patients were divided into three groups based on age at the time of the surgery. The authors expected some differences in results based on age. The youngest patients (children) haven’t finished growing yet. That factor could affect the results. The oldest group (41 and older) are subject to aging issues (degeneration) that could likewise make a difference.
Comparing the date of injury to the date of surgery and analyzing risk factors provided additional information. For example, age (older), gender (girls more than boys), and previous knee surgery were significant risk factors. For patients who had cartilage damage, the chances that they also had meniscal tears went up. The same relationship was true for those patients who had meniscal tears (meaning they were more likely to also have cartilage damage).
But most important of all, the data showed that for every month that goes by without surgery after an ACL tear, the risk of a cartilage lesion increased by one per cent. There were almost twice as many meniscal tears in the group who had reconstructive surgery late compared to those who had the operation within the first year. This relationship was true for adults but not for the children.
Surgeons often delay surgery in children until the growth plates have sealed up and the bone is fully mature. The results of this study confirm that the standard procedure of waiting until the child is at least 14 and/or reaching skeletal maturity before reconstructive surgery is probably a good idea. The delay does not seem to enhance the risk of meniscal and/or cartilage lesions.
Previous studies have shown that the timing of surgery should be determined by clinical signs and symptoms and function. For example, surgery is often delayed until swelling has gone down and motion is more normal. Other researchers have concluded that the condition of the knee at the time of surgery is actually more important than how long it’s been since the injury occurred.
The authors of this study agree with previous recommendations made that ACL reconstructive surgery should be done within the first 12 months of the initial injury. Following this timeline will help reduce the risk of meniscal tears and degenerative changes in the cartilage.