Long-Term Bilateral Neuromuscular Function and Knee Osteoarthritis after Anterior Cruciate Ligament Reconstruction

Osteoarthritis After Anterior Cruciate Ligament Reconstruction: A Systematic Review of Contributing Factors and Potential Treatments

Anterior cruciate ligament (ACL) injuries result in abnormal knee motion and long-term joint degradation. ACL reconstruction (ACLR) is done with the aim of restoring normal knee kinematics and slowing the joint degradation process. It does appear that this inevitably happens and can be impacted by a multitude of factors. The aim of this review was to examine the factors that influence the progression of osteoarthritis (OA) after ACLR and examine possible treatments that can aid in slowing that progression. A systematic review was conducted by searching all levels of evidence for all studies in English that assessed risk factors for developing OA after ACL reconstruction, had a minimum follow-up of 10 years, and used radiographical outcomes to measure the presence of OA. Studies on trial treatments to reduce osteoarthritis after ACL reconstruction were also included. It was found that among the factors associated with an increased risk of post-ACLR OA are meniscal lesions, meniscectomy, increased age at the time of ACLR, increased time from injury to surgery, male sex, reduced range of motion, smaller thigh girth, graft complications, and failure. Additionally, in performing the ACLR, anteromedial femoral tunnel placement, higher graft tension, and following guidelines for performing anatomic ACLR have been shown to reduce the risk of OA as well. Patients should be adequately counselled on their risk pre-operatively for informed decision-making. Surgeons should also be aware of potential risk factors and how they can be mitigated.

Structure and Function Are Not the Same: The Case for Restoring Mechanoreceptor Continuity Following Anterior Cruciate Ligament Injury

Anterior cruciate ligament (ACL) injury, particularly in increasingly young and active adolescents, continues to pose a clinical challenge with re-injury rates reported as high as 30%. Evidence also suggests that current standard-of-care ACL reconstruction (ACLR) does not mitigate post-traumatic osteoarthritis (PTOA) risk. Bridge- enhanced ACL restoration (BEAR) is a recently developed and tested ACL surgery that promotes primary healing of the native ACL with excellent early results. BEAR has shown to reduce signs of early PTOA compared to ACLR in an animal model. Here, we describe a theoretical framework related to re-innervation that can clarify why the outcomes of ACLR and BEAR surgeries differ. We also discuss how ongoing and new challenges in determining return-to-sport readiness following the competing surgeries may differ, and how emerging imaging tools and measures of neuromuscular function may aid in clinical decision-making to decrease the likelihood of re-injury and PTOA risk.

The Risk Factors and Preventive Strategies of Poor Knee Functions and Osteoarthritis after Anterior Cruciate Ligament Reconstruction: A Narrative Review

Anterior cruciate ligament reconstruction (ACLR) is the standard surgical treatment for ACL injury, which typically uses a graft to replace the torn ligament in the knee that uses small incisions with minimally invasive surgery. The optimal knee functions following ACLR depend on rehabilitation processes before and after the surgery. Knee function is the ability of the knee to perform various types of functional movements like walking, squatting, running, jumping, and pivoting where patients expect to achieve maximum knee function or at least more than 80% of its initial condition before the injury to avoid being categorized as poor knee function after ACLR. Patients use patient-reported outcome measures to collect data on their health status and quality of life after ACLR. Post-traumatic osteoarthritis (PTOA) is a type of OA that manifests in local cartilage injury caused by chondrocyte death, and matrix dispersion occurs following a joint injury like ACL injury. Gender, time from injury to surgery, and graft type were considered as risk factors for poor knee function after ACLR, while overweight, meniscus tear, and cartilage defect as risk factors for PTOA. However, age is an internal risk factor for both poor knee function and PTOA following ACLR. This review suggests several strategies to prevent both conditions, including a pre-operative program, comprehensive rehabilitation, body weight control, and return to sport (RTS) consideration based on physical capacity, proper time, and psychological readiness.