Degeneration of the knee joint in skeletally immature patients with a diagnosis of an anterior cruciate ligament tear: is there harm in delay of treatment?

Lawrence JT, Argawal N, Ganley TJ. Am J Sports Med. 2011 Dec;39(12):2582-7.

With nearly 38 million children playing organized sports annually in the United States, and countless more engaging in recreational sports, the opportunity for serious knee injury is more prevalent than ever.  While much research has been done to determine the best approach for treating anterior cruciate ligament (ACL) injuries in adults, the same cannot be said for skeletally immature patients.  Therefore, Lawrence et al. compared the effect of immediate ACL reconstruction and a delayed ACL reconstruction on meniscal and chondral injuries among patients 14 years of age or younger.  The authors performed a retrospective review to identify 70 ACL reconstructed knees in 69 patients with an average age of 12.9 years (range 10 to 14 years).   All patients were treated by 1 of 2 physicians utilizing similar reconstructive techniques, however one of the physicians favored delaying treatment until the patient was more skeletally mature.  The timing of the surgery was ultimately determined by the attending physician and the patient’s family.  Meniscal and chondral injuries were identified and graded through operative reports and intraoperative imaging review.  Independent variables that were examined for each patient were time from injury to surgery, the grade of medial meniscal tear (0 to 5, where 0 = no tear and 5 = irreparable tear), and the degree of chondral damage in the affected knee (0 to 4 using the Outerbridge scale).  Other risk factors that were investigated for their relationship to medial meniscal tears and chondral defects included age, sex, side, time to reconstruction, Lachman test, pivot shift test, subjective sense of instability after initial injury, and return to sports while awaiting reconstruction.  The authors were able to determine that patients undergoing surgery after waiting 12 or more weeks were 4 times more likely to have medial meniscus tears.  Patients experiencing instability, regardless of the surgical intervention timeframe, were 11 times more likely to have a medial meniscus tear.  More irreparable medial meniscus tears were identified in patients having waited longer than 12 weeks for surgery.  The authors also discovered that there was also an associated 11-fold increase in lateral femoral and 3-fold increase in patellotrochlear chondral injuries when the patients waited 12 weeks or longer for surgery.  These cartilage defects were also noted to be greater in severity as well as depth.
This study is important for many reasons; but especially because it shows that adolescents who suffer an ACL injury may be at a greater risk for meniscus tears and chondral lesions when the ACL reconstruction is delayed for more than 12 weeks.  While the authors note that this study does not determine causality, it is concerning that an adolescent’s knee is at greater risk for considerable damage when treatment is delayed.  This study illustrated that there are some serious items to consider when deciding on which treatment to select.  While there may be the potential for growth complications resulting from ACL reconstruction, are those risks outweighed by a future of knee degradation, early osteoarthritis, and potential/eventual knee arthroplasty that could result from delaying surgery?  Truly, this is a topic where the future isn’t seen through the lens of return to sport.  Are you surprised by the dramatic increase in medial meniscus and chondral cartilage injuries seen in younger patients when delaying surgery for greater than 12 weeks?  What are you and your team physician doing currently to minimize knee degeneration when your younger athletes sustain an ACL tear? 

Written by:  Mark Rice
Reviewed by:  Stephen Thomas

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Lawrence JT, Argawal N, & Ganley TJ (2011). Degeneration of the knee joint in skeletally immature patients with a diagnosis of an anterior cruciate ligament tear: is there harm in delay of treatment? The American Journal of Sports Medicine, 39 (12), 2582-7 PMID: 21917611