Lower patient-reported function at 2 years is associated with elevated knee cartilage T1rho and T2 relaxation times at 5 years in young athletes after ACL reconstruction

Objectives: Following surgical reconstruction of the anterior cruciate ligament (ACL), the tendon graft undergoes a remodeling process of ligamentization. Collagen within the ACL graft becomes organized along the long-axis of the ligament and the proteoglycan content increases. Quantitative imaging sequences, specifically T2 and T1rho, allow for a non-invasive assessment of collagen orientation and proteoglycan content, respectively. The purpose of this study was to investigate the longitudinal progression of T2 and T1rho relaxation times of the graft after ACL reconstruction and the relationship between these quantitative imaging markers and patient-reported outcome measures. We hypothesized that T2 and T1rho would decrease significantly over time, reflecting improved collagen organization and ncreased proteoglycan content, and that T2 and T1rho relaxation times would be inversely correlated with Knee Osteoarthritis Outcome Scores (KOOS). Methods: Thirty-two patients (mean age 29.4±8.2 years, 12 females) were followed prospectively after arthroscopic ACL reconstruction with hamstring autograft. Patients provided informed consent and all procedures were IRB-approved. Exclusion criteria included allograft reconstruction, other ligamentous injury, meniscal tear requiring repair, prior knee surgery, or history of arthritis. Post-operative MR imaging was obtained for 31 patients at 6 months, 30 patients at 12 months, 26 patients at 24 months, and 23 patients at 36 months after surgery. T2 and T1rho relaxation times were simultaneously acquired with a combined 3D sagittal sequence using a 3 T MR system (GE Healthcare) with a 1Tx/8Rx knee coil. The intra-articular ACL graft was identified on a fat-suppressed sagittal high-resolution 3D fast spin echo images and manually segmented. The T2 and T1rho relaxation times for the graft were recorded. Patients completed the KOOS at each imaging time point. Repeated measures analysis of variance (ANOVA) tests with Tukey corrections were used to compare T2 and T1rho relaxation times between time points. The relationship between KOOS and T2 and T1rho values at 2 years post-operative was investigated with Spearman’s rank correlation. Significance was defined as p<0.05. Results: The T2 relaxation times of the ACL graft were significantly higher at 6 months relative to 12 months (p<0.001), 24 months (p<0.001,) and 36 months (p<0.001) after ACL reconstruction, as well as significantly higher at 12 months relative to 36 months (p<0.001) (Figure 1A). The T1rho relaxation times of the ACL graft were significantly higher at 6 months relative to 12 months (p<0.001), 24 months (p<0.001), and 36 months (p<0.001) (Figure 1B). The two-year T2 relaxation times and T1rho relaxation times were significantly correlated with the KOOS Sports, Pain, Symptoms, and Activities of Daily Living sub-scores. Conclusion: We observed significant changes in the tendon graft over time following ACL reconstruction with hamstring autograft, reflecting a higher concentration of proteoglycan and more longitudinally-organized collagen structure over time. Improved collagen organization (lower T2 values) and increased proteoglycan content (lower T1rho values) were correlated with better outcomes based on KOOS scores. Quantitative T2 and T1rho relaxation times of ACL graft may offer a non-invasive method for monitoring graft maturation that correlates with patient-reported knee function after ACL reconstruction. [Figure: see text][Table: see text]

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Knee strength, hop performance and self-efficacy at 4 months are associated with symmetrical knee muscle function in young athletes 1 year after an anterior cruciate ligament reconstruction

BMJ Open Sport & Exercise Medicine ◽

10.1136/bmjsem-2018-000504 ◽

2019 ◽

Vol 5 (1) ◽

pp. e000504 ◽

Cited By ~ 3

Author(s):

Susanne Beischer ◽

Eric Hamrin Senorski ◽

Christoffer Thomeé ◽

Kristian Samuelsson ◽

Roland Thomeé

Keyword(s):

Acl Reconstruction ◽

Self Efficacy ◽

Muscle Function ◽

Knee Flexion ◽

Early Stage ◽

Knee Extension ◽

Young Athletes ◽

Patient Demographics ◽

Patient Reported ◽

Flexion Strength

ObjectivesWe investigated whether patient demographics, 4-month patient-reported outcomes (PRO) and muscle function predicted young athletes regaining symmetrical muscle function in five tests of muscle function 1 year after ACL reconstruction.MethodsWe extracted data on patient demographics, PROs and the results of five tests of muscle function from a rehabilitation-specific register. Athletes were 15–30 years of age, involved in knee-strenuous sport and had undergone a primary ACL reconstruction. The primary outcome was achieving a Limb Symmetry Index of ≥90% for the battery of tests 1 year after ACL reconstruction. Patient demographics, muscle-function data and results for PROs at the 4-month follow-up were analysed.ResultsIn all, 237 athletes (59% female; mean age 22±4 years) were included in the study. One year after ACL reconstruction, 26% (62/237) of the included athletes had achieved symmetrical muscle function. Univariable analysis showed that symmetrical muscle function was associated with present self-efficacy, OR 1.28 (95% CI 1.04 to 1.58, p=0.011), knee-extension strength, OR 1.73 (95% CI 1.28 to 2.34), knee-flexion strength, OR 1.39 (95% CI 1.07 to 1.81), vertical hop, OR 1.77 (95% CI 1.27 to 2.45), single-leg hop for distance, OR 1.98 (95% CI 1.24 to 3.17) and side hop, OR 1.64 (95% CI 1.15 to 2.33).ConclusionSymmetrical knee-extension and knee-flexion strength, a more symmetrical hop performance and higher present self-efficacy at an early stage all increased the odds of achieving symmetrical muscle function in young athletes 1 year after ACL reconstruction.

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Response of knee cartilage T1rho and T2 relaxation times to in vivo mechanical loading in individuals with and without knee osteoarthritis

Osteoarthritis and Cartilage ◽

10.1016/j.joca.2014.04.017 ◽

2014 ◽

Vol 22 (10) ◽

pp. 1367-1376 ◽

Cited By ~ 61

Author(s):

R.B. Souza ◽

D. Kumar ◽

N. Calixto ◽

J. Singh ◽

J. Schooler ◽

...

Keyword(s):

Knee Osteoarthritis ◽

Mechanical Loading ◽

Relaxation Times ◽

Knee Cartilage ◽

T2 Relaxation

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Current Return to Sport Criteria after ACL Reconstruction Fail to Identify Increased Risk of Second ACL Injury in Young Athletes

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967118s00060 ◽

2018 ◽

Vol 6 (7_suppl4) ◽

pp. 2325967118S0006 ◽

Cited By ~ 2

Author(s):

Mark V. Paterno ◽

Mitchell Rauh ◽

Staci Thomas ◽

Timothy E. Hewett ◽

Laura Schmitt

Keyword(s):

Acl Reconstruction ◽

Group Analysis ◽

Return To Sport ◽

Acl Injury ◽

Quadriceps Strength ◽

Patient Reported Outcome ◽

Young Athletes ◽

Increased Risk ◽

Significant Difference ◽

Patient Reported

Objectives: The incidence of 2nd anterior cruciate ligament (ACL) injury after ACL reconstruction (ACLR) and return to sport (RTS) ranges from 25%-33% in young, active populations; with the greatest risk in the first 12 months after RTS. Recent data indicate that failure to successfully meet traditional RTS criteria, inclusive of strength, functional hop testing and patient reported outcome scores, may identify athletes at increased risk of future injury after ACLR. However, these studies have focused on adult populations and it is unknown if similar RTS criteria apply to young, adolescent, pivoting/cutting athletes. The purpose of this study was to determine if meeting all current, standard RTS criteria would identify young athletes at risk for future ACL injury after primary ACLR and RTS. The tested hypothesis was the likelihood of 2nd ACL injury in the first 2 years after RTS would be lower in patients who met all RTS criteria prior to initiation of pivoting and cutting activity compared to patients who failed to meet all RTS criteria prior to RTS. Methods: One hundred fifty-nine subjects (112 female, 47 male) with a mean age of 17.2±2.6 years old (range: 13-25 y.o.) underwent ACLR and were released to return to pivoting/cutting sport. These patients were enrolled in a prospective, observational cohort study, completed a RTS assessment and were then tracked for occurrence of 2nd ACL after ACLR for 24 months. The RTS assessment included 6 tests: isometric quadriceps strength, 4 functional hop tests and the International Knee Documentation Committee (IKDC) patient reported outcome survey. Limb symmetry index (LSI) was calculated for strength and hop test assessments [(involved/uninvolved)*100]. The IKDC was reported on a 0-100 scale with 100 representing a perfect score. Subjects were classified into groups that successfully passed all 6 RTS tests at a level of 90 and again at 95 compared to those that failed to meet all 6 criteria. Chi Square tests were used to determine if successfully passing all 6 RTS measures at various levels of symmetry resulted in a reduced risk of 2nd ACL injury in the first 24 months after RTS. Results: Thirty-five (22.0%) patients suffered a 2nd ACL injury, with 26 occurring in the first 12 months after RTS. At the time of RTS, 42 patients (26%) achieved LSI values of 90 or greater on all testing as well as an IKDC value of 90 or greater. The remaining 117 subjects (74%) scored below 90 on at least 1 of the 6 assessments. At this level, there was no difference in 2nd ACL injury prevalence between patients who passed all RTS criteria (12/42; 28.6%) and those who failed at least 1 criteria (23/117; 19.7%) (p=0.23). When the passing criteria was elevated to 95 on all RTS testing, only 15 subjects (9%) successfully passed all 6 tests. There was no significant difference in 2nd ACL injury prevalence between patients who passed all RTS criteria (5/15; 33%) and those who failed at least 1 test (30/144; 20.8%) (p=0.32). Sub-group analysis which evaluated the group by graft type, also indicated no significant differences between groups (p>0.05). Conclusion: Current criteria to evaluate readiness to return young athletes to pivoting and cutting sports, using quadriceps strength symmetry, functional hop performance symmetry and patient reported outcomes, may not identify young, active patients at high risk for 2nd ACL injury. Future work must identify more appropriate criteria to assess readiness to RTS in the young, athletic population and incorporate these findings into practice.

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Effects of Surgical Factors on Cartilage Can Be Detected Using Quantitative Magnetic Resonance Imaging After Anterior Cruciate Ligament Reconstruction

The American Journal of Sports Medicine ◽

10.1177/0363546516677794 ◽

2017 ◽

Vol 45 (5) ◽

pp. 1075-1084 ◽

Cited By ~ 7

Author(s):

Keiko Amano ◽

Alan K. Li ◽

Valentina Pedoia ◽

Matthew F. Koff ◽

Aaron J. Krych ◽

...

Keyword(s):

Anterior Cruciate Ligament ◽

Magnetic Resonance ◽

Cruciate Ligament ◽

Relaxation Times ◽

Patient Reported Outcome Measures ◽

Patient Reported Outcome ◽

Meniscal Tears ◽

T2 Relaxation ◽

Patient Reported ◽

Anterior Cruciate

Background: Quantitative magnetic resonance (qMR) can be used to measure macromolecules in tissues and is a potential method of observing early cartilage changes in the development of posttraumatic osteoarthritis. Hypothesis/Purpose: We hypothesized that specific patient and surgical factors affecting cartilage matrix composition after anterior cruciate ligament (ACL) reconstruction (ACLR) can be detected using T1ρ and T2 relaxation times. Our purpose was to demonstrate this ability in a multicenter feasibility study. Study Design: Case series; Level of evidence, 4. Methods: A total of 54 patients who underwent ACLR underwent bilateral MRI at baseline before surgery and 6 months postoperatively. Operative findings were recorded. T1ρ and T2 relaxation times were calculated for 6 cartilage regions: the medial femur, lateral femur, medial tibia, lateral tibia, patella, and trochlea. A paired t test compared relaxation times at baseline and 6 months, univariate regression identified regions that influenced patient-reported outcome measures, and analysis of covariance was used to determine the surgical factors that resulted in elevated relaxation times at 6 months. Results: The injured knee had significantly prolonged T1ρ and T2 relaxation times in the tibiofemoral compartment at baseline and 6 months but had shorter values in the patellofemoral compartment compared with the uninjured knee. Prolonged T1ρ and T2 times at 6 months were noted for both the injured and uninjured knees. At 6 months, prolongation of T1ρ and T2 times in the tibial region was associated with lower patient-reported outcome measures. ACLR performed within 30 days of injury had significantly shorter T1ρ times in the tibial regions, and lateral meniscal tears treated with repair had significantly shorter T1ρ times than those treated with excision. Conclusion: Prolonged relaxation times in multiple regions demonstrate how the injury affects the entire joint after an ACL tear. Changes observed in the uninjured knee may be caused by increased loading during rehabilitation, especially in the patellofemoral articular cartilage and distal femur. Relaxation times in the tibial regions may be predictive of patient symptoms at 6 months. These same regions are affected by surgical timing as early as 30 days after injury, but this may partially be reflective of the severity of the preoperative injury and the choice of treatment of meniscal tears.

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