Osteoarthritis Progression after ACL Reconstruction Was Significantly Higher Than That of the Healthy Contralateral Knees: Long-Term Follow Up Study of Mean 16.4 Years

Comparative Evaluation of Arthritic Changes in Post-operative Patients With Anterior Cruciate Ligament (ACL) Injuries: A Study of Exercising Versus Sedentary Individuals

BACKGROUND

Anterior cruciate ligament (ACL) injury has become quite a common injury affecting the knee in young and middle-aged individuals. ACL reconstruction is a common surgical intervention indicated after a grade 3 rupture. Meanwhile, early arthritic changes start to appear after five years post-ACL reconstruction. Increased knowledge about regular exercise after ACL reconstruction in the sedentary population can decrease or reduce the chances of having early arthritic changes in the knee. Therefore, a study is needed to find the prevalence of arthritic changes in the exercising and sedentary postoperative ACL injury patients.

MATERIALS AND METHODS

The population was divided into sedentary and exercising populations. The exercising population was further divided into low, moderate, and high-intensity exercises based on the target heart rate range and maximum heart rate. Radiographs just before surgery or immediate post-operative versus recent radiographs (after five years) were used to assess the knee joints of exercising and sedentary populations by using the Kellgren and Lawrence classification (KLC) to measure the severity of knee osteoarthritis.

RESULTS

In the exercising population, only 4(9.52%) of the individuals were found to have arthritic changes in their knee, whereas, in the sedentary population, 10(18.51%) of the individuals had arthritic changes in their knee post-ACL reconstruction after five years. Lack of regular exercise after ACL reconstruction showed early arthritic changes compared to those who were physically active, indicating the impact of physical activity.

CONCLUSIONS

This study concludes that a greater number of the sedentary population had arthritic changes in their knee joints post-surgery than those who were physically active, highlighting the significance of regular exercise.

Prevalence of post-traumatic osteoarthritis after anterior cruciate ligament injury remains high despite advances in surgical techniques

Aims

The aim of this study was to report the pooled prevalence of post-traumatic osteoarthritis (PTOA) and examine whether the risk of developing PTOA after anterior cruciate ligament (ACL) injury has decreased in recent decades.

Methods

The PubMed and Web of Science databases were searched from 1 January 1980 to 11 May 2022. Patient series, observational studies, and clinical trials having reported the prevalence of radiologically confirmed PTOA after ACL injury, with at least a ten-year follow-up, were included. All studies were analyzed simultaneously, and separate analyses of the operative and nonoperative knees were performed. The prevalence of PTOA was calculated separately for each study, and pooled prevalence was reported with 95% confidence intervals (CIs) using either a fixed or random effects model. To examine the effect of the year of injury on the prevalence, a logit transformed meta-regression analysis was used with a maximum-likelihood estimator. Results from meta-regression analyses were reported with the unstandardized coefficient (β).

Results

The pooled prevalence of PTOA was 37.9% (95% CI 32.1 to 44) for operatively treated ACL injuries with a median follow-up of 14.6 years (interquartile range (IQR) 10.6 to 16.7). For nonoperatively treated ACL injuries, the prevalence was 40.5% (95% CI 28.9 to 53.3), with a median of follow-up of 15 years (IQR 11.7 to 20.0). The association between the year of operation and the prevalence of PTOA was weak and imprecise and not related to the choice of treatment (operative β -0.038 (95% CI -0.076 to 0.000) and nonoperative β -0.011 (95% CI -0.101 to 0.079)).

Conclusion

The initial injury, irrespective of management, has, by the balance of probability, resulted in PTOA within 20 years. In addition, the prevalence of PTOA has only slightly decreased during past decades. Therefore, further research is warranted to develop strategies to prevent the development of PTOA after ACL injuries.

Determine the vertical ground reaction forces and knee mechanics with different gait inclinations in the sheep model

Our current understanding of knee mechanics and anterior cruciate ligament (ACL) function is predominately based on data recorded during simulations of clinical examinations or the application of nonphysiologic loads and motions. These methodologies provide little information on knee and ACL mechanics during activities of daily living (ADLs). Additionally, researchers have not directly measured knee kinetics, knee contact pressures, and ACL forces, and it is unknown how these parameters change with different activities. This study quantified the effects of activity level on vertical ground reaction forces, knee kinematics, and joint and ligament forces during in vivo motions. Five female Suffolk sheep were walked twice weekly on a treadmill during level (0°), inclined (+6°), and declined (-6°) gait for 12 weeks. Electromagnetic (EM) trackers were surgically implanted onto the left distal femur and the left proximal tibia, and in vivo motions were recorded for all activities. Following sacrifice, the in vivo motions were applied to their respective knees using a serial robot with a multi-axis load cell. In vitro simulations were repeated to measure (a) total knee forces, (b) contact pressure maps, and (c) ACL-only forces. Declining the gait surface led to increased posterior translation during the swing phase and decreased flexion at hoof-strike, decreased medial contact pressure at push-off, decreased ACL force at hoof-strike and increased ACL force at push-off. This study established a system that can be used to examine knee mechanics and ACL forces during ADLs for different knee states to define design requirements for ACL reconstruction techniques.