CORR Insights®: Younger Patients and Men Achieve Higher Outcome Scores Than Older Patients and Women After Anterior Cruciate Ligament Reconstruction

Clinical Orthopaedics and Related Research® -     

Editorial Commentary: Patellar Tendon or Hamstring: Which Kind of Anterior Cruciate Ligament Patient Are You?

The role of graft selection on clinical and functional outcomes following anterior cruciate ligament (ACL) reconstruction has gained significant attention in the orthopaedic sports medicine community in recent years. Bone–patellar tendon–bone (BPTB) and semitendinosus/gracilis hamstring tendon (HT) autografts are 2 of the most commonly used grafts, given their low failure rates, predictable outcomes, and ability to incorporate appropriately at the graft site. However, multiple studies have recently shown each of these graft options to have some potentially less-desirable characteristics in regards to outcomes in specific patient populations. More specifically, in 14- to 25-year-old athletes, HT autografts have been shown to result in decreased rotational stability, decreased return to sport rates, and increased graft failure rates. On the other hand, BPTB autografts can require a prolonged recovery period and have been associated with increased postoperative pain and long-term kneeling pain. HT and BPTB grafts are both excellent grafts; however, it is important to understand the differences in clinical and functional outcomes between these graft options for ACL reconstruction. The characteristics of the graft need to be considered and individualized for each patient who is being treated for an ACL injury.     

Editorial Commentary: Are Adjustable-Length Loop Devices Adequate for Femoral Fixation of Anterior Cruciate Ligament Graft?

To date, there is no consensus regarding which type of cortical suspension device is biomechanically superior during anterior cruciate ligament reconstruction. Retensioning or knotting has been reported to improve the biomechanical profile of adjustable-length devices, although fixed-length devices demonstrated overall superior biomechanical properties. Intraoperative or postoperative loop slippage and graft displacement should be investigated in future clinical and radiographic studies including serial magnetic resonance imaging.     

Is There Value and Validity for the Use of Return to Sport Test Batteries After Anterior Cruciate Ligament Injury and Reconstruction?

Is there value and validity for the use of return-to-sport (RTS) test batteries? With regard to RTS testing, there has been marked interest and rapid growth in studies that document RTS criteria after anterior cruciate ligament reconstruction. A set of criteria or “test-battery” is typically used to “clear” the athlete for RTS. Although most RTS testing is done with aim of assessing safety, the same measurements can be as used to determine the amount of functional capacity regained. It is suggested that RTS test batteries incorporate multiple domains of risk factors. If testing “works,” patients who pass should have a lower risk of reinjury than patients who fail but nonetheless return to sport. More recent studies have attempted to cover a broad range of risk factors, with as many as 15 to 20 RTS tests. This is possibly due to a lack of clear evidence as to what are the most important risk factors for second injury. As a result, few patients pass these combined criteria. Findings from a meta-analysis showed that there is a low rate of passing RTS testing (23%). The findings from this and a second meta-analyses are quite similar, as both showed there was no effect of passing RTS test batteries on overall subsequent anterior cruciate ligament injury. There was a 7% to 9% reduction in risk difference of graft injuries with passing of RTS; however, there was a 4% to 9% risk difference or 176% to 235% increased risk of a contralateral injury with passing of RTS criteria. There remain several problems with RTS test batteries, which include low rates of meeting thresholds, many athletes return without meeting RTS thresholds, evidence for predictive value is limited, small sample sizes in many studies (only 2 studies >100 patients), and many studies don’t document RTS rates. Additional issues include questions as to whether testing should be staged, how to monitor progression of rehabilitation, and should these RTS batteries be tailored to age groups?     

Editorial Commentary: Anterior Cruciate Ligament Tibial Eminence Avulsion Fractures: Are They Trying to Tell Us Something?

Arthroscopic reduction and fixation of tibial eminence avulsion fractures has excellent clinical results and adequately restores anterior cruciate ligament function with a low rate of complications. Clinical outcomes are preserved at an average of 8 years, and the incidence of osteoarthritis is low at midterm follow up. These injuries may represent the best-case scenarios of anterior cruciate ligament injury because they represent lower energy injuries without significant associated meniscal or chondral pathologies. These findings may give us additional clues about which patients are the best candidates for primary anterior cruciate ligament repair in the setting of femoral-sided avulsions.     

Editorial Commentary: Increased Tibial Slope Is Associated With Anterior Cruciate Ligament Injury Risk,and Tibial Slope Increases in the Skeletally Immature,Anterior Cruciate Ligament-Deficient Knee: A Chicken or Egg Causality Dilemma?

Increased tibial slope is associated with increased risk of anterior cruciate ligament (ACL) injury in the skeletally immature. Recent studies, however, emphasize a mutual influence, as tibial slope has been shown to increase over time in the ACL-deficient skeletally immature knee. It is hypothesized that altered biomechanics with enhanced posterior force transmission in the ACL-deficient knee may influence the developing physis, leading to altered longitudinal growth and increased tibial slope. In addition to tibial slope, the meniscal geometry, including meniscal bone angle and meniscal slope, have been shown to influence the risk of ACL injury. In the skeletally immature knee, especially, the soft tissue geometry is thought to have significant impact on ACL injury risk. However, it remains unknown whether alteration of the meniscal slope may represent a causality of ACL deficiency.