CORR Insights®: Younger Patients and Men Achieve Higher Outcome Scores Than Older Patients and Women After Anterior Cruciate Ligament Reconstruction
Where Are We Now?
Parameters such as knee laxity, muscle force, hop tests, and patient-related outcome (PRO) scores are essential in evaluating patients after ACL reconstruction, and they can be especially useful when determining whether a patient is fit to return to sport after surgery. These parameters can also be used as tools to optimize treatment decisions (whether to operate or not), define the best time to operate , or reduce the reinjury risk at the time of return to sport .
In the current study, Drs. Webster and Feller provide a broad overview of a large cohort of patients who underwent ACL reconstruction. They confirmed that patients who did not return to sport or only managed to go back to training had achieved lower outcome scores, persistent deficits in hop tests, and increased laxity than those returning to preinjury level of competition. While these differences in ACL reconstruction outcomes are consistent with previous reports [1, 2], this report is the first to my knowledge to provide a clear overview of a wide range of clinical criteria in a large population.
Where Do We Need To Go?
The influence of gender, age, and return to sport on ACL reconstruction outcomes reported in the current study highlights the need to evaluate patients and decide of their treatment and ability to return to sport on an individual basis. However, we still need a better understanding of the results after ACL reconstruction.
To date, there is no consensus defining what elements make ACL reconstruction successful. Return to sport could be an indicator, as might side-to-side deficits in muscle forces or hop-test differences of less than 10%. That said, at 24 months after ACL reconstruction, only 48% of patients achieve this threshold in a muscle force test battery and 44% in a hop-tests battery . On the other hand, more patients declare to have returned to sport (81% of ACL-reconstructed patients return to any sport and 55% return to competitive levels ). Thus, there is a gap between expectations, recommendations, and the current status of ACL-reconstructed patient outcomes. It seems important, therefore, to clarify the thresholds that athletes should reach at given time points, in order to help provide realistic goals and benchmarkes on the way to returning them to sport. This may help avoid graft reruptures and secondary injury.
While the current study reports on knee laxity, hop tests, and PRO parameters, muscle force should also be explored as muscle recovery is reported to be delayed in elderly patients . References for each outcome parameter should be established for the followup of homogeneous groups of patients. Furthermore, additional influencing factors and their interactions need to be considered. Cartilage injury and meniscus tear, observed in up to 70% of patients with ACL injuries , should also be investigated due to their impact on subjective outcomes . The main challenge will be evaluating the clinical relevance of the influence of each factor.
Patients undergoing preoperative rehabilitation and those with preoperative quadriceps force deficits below 20% have higher KOOS scores and lower deficits in muscle strength, respectively 2 years after the ACL reconstruction [5, 6]. However, the effects of preoperative rehabilitation, the delay between injury and surgery, and baseline data before surgery, are less understood. Little is actually known regarding which parameters influence preoperative status in these regards. Although older patients have lower preoperative KOOS scores, they display results similar to younger patients after ACL reconstruction . Would a nonsurgical approach yield similar results for older patients? Further investigations of the preoperative period are needed to better understand the benefit of ACL reconstructions as well as help us determine whether outcome differences are linked to the injury itself or the ACL reconstruction.
How Do We Get There?
Surgeons are challenged with understanding the complex factors that influence patient outcomes. In order to improve the outcomes of patients who undergo ACL-reconstruction, we must develop better patient-education tools, establish goals with each patient, and systematically evaluate patients with repeated functional testing throughout their followup . The establishment of center-based registries  should be encouraged to save testing data until 1 year to 2 years after the surgery. Such databases would bear some advantages over national registries. At smaller scale centers, more outcome parameters (including functional scores such as hop test and muscle strength) could be evaluated and the testing protocols could be highly standardized to enhance data quality. This systematic and standardized approach would have several benefits: (1) Averages, medians, and percentiles could be easily extracted from the database. (2) Each center could potentially establish internal references and goals (such as to systematically report patients within the 10% of lower outcomes and consider multidisciplinary options for these patients). (3) These data could also be used throughout the followup of patients to show them clear goals and to maintain their motivation.
- 2.Ardern CL, Taylor NF, Feller JA, Webster KE. Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: An updated systematic review and meta-analysis including aspects of physical functioning and contextual factors. Br J Sports Med. 2014;48:1543–1552.CrossRefPubMedGoogle Scholar
- 3.Cox CL, Huston LJ, Dunn WR, Reinke EK, Nwosu SK, Parker RD, Wright RW, Kaeding CC, Marx RG, Amendola A, McCarty EC, Spindler KP. Are articular cartilage lesions and meniscus tears predictive of IKDC, KOOS, and Marx activity level outcomes after anterior cruciate ligament reconstruction? A 6-year multicenter cohort study. Am J Sports Med. 2014;42:1058–1067.Google Scholar
- 6.Grindem H, Granan LP, Risberg MA, Engebretsen L, Snyder-Mackler L, Eitzen I. How does a combined preoperative and postoperative rehabilitation programme influence the outcome of ACL reconstruction 2 years after surgery? A comparison between patients in the Delaware-Oslo ACL Cohort and the Norwegian National Knee Ligament Registry. Br J Sports Med. 2015;49:385–389.CrossRefPubMedGoogle Scholar