Fifteen-year survival of endoscopic anterior cruciate ligament reconstruction in patients aged 18 years and younger

Background: The current body of literature surrounding anterior cruciate ligament (ACL) survival and the variables contributing to further ACL injuries after primary ACL reconstruction in children and adolescents is limited, with no long-term evidence examining the incidence and contributing factors of further ACL injuries in this younger patient population. Purpose: To determine the long-term survival of the ACL graft and the contralateral ACL (CACL) after primary reconstruction in patients aged 18 years and to identify the factors that increase the odds of subsequent ACL injuries. Study Design: Case series; Level of evidence, 4. Methods: Patients having undergone primary ACL reconstruction at age 18 years between 1993 and 1998 who were included in a prospective database by a single surgeon were considered for this study. Single-incision endoscopic ACL reconstruction was performed with either an autologous bone–patellar tendon–bone graft or a hamstring tendon graft. At a minimum of 15 years after ACL reconstruction, patients completed a subjective survey involving the International Knee Documentation Committee (IKDC) questionnaire in addition to questions regarding current symptoms, further ACL injuries, family history of ACL injury, and current level of activity. Results: A total of 288 adolescents (age range, 13-18 years) met the inclusion criteria, of whom 242 (84%) were reviewed at a mean of 16 years and 6 months after ACL reconstruction. Of these patients, 75 (31%) sustained a further ACL injury: 27 (11.2%) suffered an ACL graft rupture, 33 suffered a CACL injury (13.6%), and 15 sustained both an ACL graft rupture and a CACL injury (6.2%) over 15 years. Survival of the ACL graft was 95%, 92%, 88%, 85%, and 83% at 1, 2, 5, 10, and 15 years, respectively, and survival of the CACL was 99%, 98%, 90%, 83%, and 81%, respectively. Survival of the ACL graft was less favorable in those with a family history of ACL injury than in those without a family history (69% vs 90%, respectively; hazard ratio [HR], 3.6; P = .001). Survival of the CACL was less favorable in male patients than in female patients (75% vs 88%, respectively; HR, 2.1; P = .03) and in those who returned to competitive team ball sports than in those who did not (78% vs 89%, respectively; HR, 2.3; P = .05). Conclusion: After ACL reconstruction in patients aged 18 years, a further ACL injury occurred in 1 in 3 patients over 15 years. The 15-year survival rate of the ACL graft was 83%, and the 15-year survival rate of the CACL was 81%. The ACL graft and CACL were most vulnerable within the first 5 years after index surgery. A family history of ACL rupture significantly increased the risk for ACL graft ruptures, and a CACL injury was more common in male patients and those who returned to team ball sports. High IKDC scores and continued participation in sports were maintained over the long term after ACL reconstruction in the adolescent population

Twenty-year outcomes of a longitudinal prospective evaluation of isolated endoscopic anterior cruciate ligament reconstruction with patellar tendon autografts

Background: Long term prospective follow up studies of single-incision endoscopic anterior cruciate ligament reconstruction are limited and may include confounding factors. Objectives: This longitudinal prospective study reports the outcome of isolated anterior cruciate ligament (ACL) reconstruction using middle-third patellar tendon autograft in 90 patients over 20 years. Study design: Case series; Level of evidence, 4. Methods: Between January 1993 and April 1994, 90 patients met study inclusion criteria, evaluation 1,2,3,4,5,7,10,15 and 20 years post-surgery. Exclusion criteria: associated ligamentous injury requiring surgery, previous meniscectomy; meniscal injury meniscectomy more than 1/3; chondral injury; and an abnormal contralateral knee. Results: At 20 years, 32(36%) patients had sustained another ACL injury, 8(9%) to the index limb and 27(29%) to the contralateral limb (3 injuring both knees). Mean IKDC score was 86, 50% participated in strenuous/very strenuous activities, kneeling pain was present in 63%. Radiographic degenerative change was found in 61%, 20% IKDC Grade C, 0% Grade D. IKDC clinical examination revealed 95% had a normal/nearly normal knee. Significant gender differences existed: females were less likely to re-injure the reconstructed ACL (18%v2%, p=0.01), reported poorer IKDC subjective score (90v83, p=0.03), had more activity related pain (57%v20%, p=0.02), and less likely to participate in strenuous activity (35v66, p=0.01). ACL graft survival was not related to age. Patients \u3c18years old had an increased odd ratio (3.2) for rupturing the contralateral ACL. Coronal graft angles \u3c17 degrees had increased risk of failure compared to those over 17 degrees (96% v 77%), by a factor of 8.5. Conclusion: Injury commonly occurred in the contralateral ACL than the reconstructed ACL graft, the most significant predictor of contralateral ACL injury is age under 18yrs. The most significant predictor of ACL graft rupture is a coronal graft angle of less than 17 degrees. Females had lower re- rupture rates, poorer subjective scores, decreased participation in strenuous activity, putting the graft at less risk of failure. Kneeling pain remained persistent over 20 years. Radiographic osteoarthritis was evident in 61% of subjects but symptomatic osteoarthritic symptoms were rarely reported

Measuring theoretical and actual observation influence in the Met Office UKV: application to Doppler radial winds

In numerical weather prediction it is important to objectively measure the value of the observations assimilated. However, methods such as the forecast sensitivity to observation impact and observing system experiments are dfficult to apply to convective scale data assimilation (DA) systems such as the Met Office's UKV. We develop a new method to estimate the influence of the observations on the analysis, acknowledging that the influence depends not only on the uncertainty in the observations and prior, but how well these are prescribed in the assimilation. Monitoring both the actual and theoretical observation influence can ag observations that are being assimilated incorrectly and quantify the harm caused to the analysis. By applying these new estimates of the observation influence to the assimilation of Doppler Radial Winds in the UKV system, we demonstrate their ability, along with expert knowledge, to inform the optimisation of both the observation network and DA system

Plant microbiome analysis after Metarhizium amendment reveals increases in abundance of plant growth-promoting organisms and maintenance of disease-suppressive soil

The microbial community in the plant rhizosphere is vital to plant productivity and disease resistance. Alterations in the composition and diversity of species within this community could be detrimental if microbes suppressing the activity of pathogens are removed. Species of the insect-pathogenic fungus, Metarhizium, commonly employed as biological control agents against crop pests, have recently been identified as plant root colonizers and provide a variety of benefits (e.g. growth promotion, drought resistance, nitrogen acquisition). However, the impact of Metarhizium amendment on the rhizosphere microbiome has yet to be elucidated. Using Illumina sequencing, we examined the community profiles (bacteria and fungi) of common bean (Phaseolus vulgaris) rhizosphere (loose soil and plant root) after amendment with M. robertsii conidia, in the presence and absence of an insect host. Although alpha diversity was not significantly affected overall, there were numerous examples of plant growth-promoting organisms that significantly increased with Metarhizium amendment (Bradyrhizobium, Flavobacterium, Chaetomium, Trichoderma). Specifically, the abundance of Bradyrhizobium, a group of nitrogen-fixing bacteria, was confirmed to be increased using a qPCR assay with genus-specific primers. In addition, the ability of the microbiome to suppress the activity of a known bean root pathogen was assessed. The development of disease symptoms after application with Fusarium solani f. sp. phaseoli was visible in the hypocotyl and upper root of plants grown in sterilized soil but was suppressed during growth in microbiome soil and soil treated with M. robertsii. Successful amendment of agricultural soils with biocontrol agents such as Metarhizium necessitates a comprehensive understanding of the effects on the diversity of the rhizosphere microbiome. Such research is fundamentally important towards sustainable agricultural practices to improve overall plant health and productivity.Brock University Library Open Access Publishing Fun