Eva Tengman

Anterior cruciate ligament injury after more than 20 years: I. Physical activity level and knee function

Little is known about physical activity level and knee function including jump capacity and fear of movement/reinjury more than 20 years after injury of the anterior cruciate ligament (ACL). Seventy persons with unilateral ACL injury participated (23 ± 2 years post‐injury): 33 treated with physiotherapy in combination with surgical reconstruction (ACLR), and 37 treated with physiotherapy alone (ACLPT). These were compared with 33 age‐ and gender‐matched controls. Assessment included knee‐specific and general physical activity level [Tegner activity scale, International Physical Activity Questionnaire (IPAQ)], knee function [Lysholm score, Knee injury and Osteoarthritis Outcome Score (KOOS)], jump capacity (one‐leg hop, vertical jump, side hops), and fear of movement/reinjury [Tampa Scale for Kinesiophobia (TSK)]. Outcomes were related to degree of osteoarthritis (OA). ACL‐injured had lower Lysholm, KOOS, and Tegner scores than controls (P < 0.001), while IPAQ score was similar. ACL‐injured demonstrated inferior jump capacity in injured compared with noninjured leg (6–25%, P < 0.001–P = 0.010 in the different jumps), while noninjured leg had equal jump capacity as controls. ACL groups scored 33 ± 7 and 32 ± 7 of 68 on TSK. Lower scores on Lysholm and KOOS symptom were seen for persons with moderate‐to‐high OA than for no‐or‐low OA, while there were no differences for physical activity and jump capacity. Regardless of treatment, there are still negative knee‐related effects of ACL injury more than 20 years later.

Anterior cruciate ligament injury after more than 20 years. II. Concentric and eccentric knee muscle strength.

The long‐term consequences on knee muscle strength some decades after rupture of the anterior cruciate ligament (ACL) are not established. The aims of our study were to examine peak torque more than 20 years after ACL injury and to compare their knee muscle strength to that of healthy controls. We tested 70 individuals with unilateral ACL injury 23 ± 2 years after injury, whereof 33 (21 men) were treated with physiotherapy in combination with ACL reconstruction (ACLR) and 37 (23 men) with physiotherapy alone (ACLPT). These were compared with 33 age‐ and gender‐matched controls (21 men). A Kin‐Com® dynamometer (90°/s) was used to measure peak torque in knee flexion and extension in both concentric and eccentric contractions. Knee extension peak torque, concentric and eccentric, was ∼10% lower for the injured leg compared with the non‐injured leg for both ACLR (P < 0.001; P < 0.001) and ACLPT (P = 0.007; P = 0.002). The ACLPT group also showed reduced eccentric knee flexion torque of the injured leg (P = 0.008). The strength of the non‐injured leg in both ACL groups was equal to that of controls. No difference was seen for those with no‐or‐low degree of knee osteoarthritis compared to those with moderate‐to‐high degree of osteoarthritis. ACL injury may lead to a persistent reduction of peak torque in the injured leg, which needs to be considered across the lifespan.

Anterior cruciate ligament injury about 20 years post-treatment : a kinematic analysis of one-leg hop

Reduced dynamic knee stability, often evaluated with one‐leg hops (OLHs), is reported after anterior cruciate ligament (ACL) injury. This may lead to long‐standing altered movement patterns, which are less investigated. 3D kinematics during OLH were explored in 70 persons 23 ± 2 years after ACL injury; 33 were treated with physiotherapy in combination with ACL reconstruction (ACLR) and 37 with physiotherapy alone (ACLPT). Comparisons were made to 33 matched controls. We analyzed (a) maximal knee joint angles and range of motion (flexion, abduction, rotation); (b) medio‐lateral position of the center of mass (COM) in relation to knee and ankle joint centers, during take‐off and landing phases. Unlike controls, ACL‐injured displayed leg asymmetries: less knee flexion and less internal rotation at take‐off and landing and more lateral COM related to knee and ankle joint of the injured leg at landing. Compared to controls, ACLR had larger external rotation of the injured leg at landing. ACLPT showed less knee flexion and larger external rotation at take‐off and landing, and larger knee abduction at Landing. COM was more medial in relation to the knee at take‐off and less laterally placed relative to the ankle at landing. ACL injury results in long‐term kinematic alterations during OLH, which are less evident for ACLR.

Deficits in single-limb stance more than 20 years after ACL injury

Abstract Aim: To investigate the long-term effect on balance during single-limb stance after unilateral anterior cruciate ligament (ACL) injury across two groups who had rehabilitation including ACL reconstruction (ACLR) or a tailored physiotherapy program (ACLTPP), compared with knee-healthy controls. Methods: Single-limb stance was monitored for floor-supports with the contralateral foot. Single-limb stance without floor-supports was assessed with analyses of center of pressure (CoP) for further discrimination. Comparisons were made between ACLR (n = 28) and ACLTPP (n = 28) and with controls (n = 18). The injured and uninjured legs were compared within ACL-injured subjects. Results: Single-limb balance was equally inferior in both ACL-injured groups and on both legs compared with knee-healthy controls. In ACLR and ACLTPP, 39% and 50%, respectively, failed to stand on one leg without floor-supports with the contralateral foot. No contralateral supports occurred in knee-healthy controls. CoP measures for subjects who stood without contralateral floor-supports did not reveal any further differences. Older age and higher body mass index (BMI) correlated with larger migration of CoP. Conclusion: Inability to stand without contralateral supports showed that balance in single-limb stance was inferior in ACL-injured subjects, independently of which initial treatment that was given. Age and BMI need consideration in studies assessing balance in single-limb stance.

Altered postural control strategies in quiet standing more than 20 years after rupture of the anterior cruciate ligament

AIM To explore long-term consequences of anterior cruciate ligament (ACL) rupture on postural sway and control strategies during bilateral quiet standing, in subjects treated with or without reconstructive surgery compared to uninjured controls. METHOD 70 individuals who had unilateral ACL rupture 23±2.4 years ago (33 received ACL reconstructive surgery, ACLR, and 37 had physiotherapy only, ACLPT) and 33 uninjured matched controls (CTRL) (mean age 46±5.3) stood quietly with eyes closed for 3min on a firm and on a compliant surface, respectively. Center of pressure (CoP) was registered with a force plate and postural sway was calculated from center of mass (CoM) derived from 3D kinematics. Sway density (SD) analyses of CoP assessed distance and duration of stable phases. The torque controlling postural sway was estimated from CoP-CoM. RESULTS Comparisons across conditions to CTRL revealed larger CoP-CoM-area in ACLR (p=0.017, CI: 10.95, 143.10), but not in ACLPT. Mean distance between SD-peaks was greater for ACLR (p<0.001, CI: 1.73, 5.31) than for ACLPT (p=0.006, CI: 0.56, 4.12) relative to CTRL. Duration of SD-peaks was smaller for both ACLR and ACLPT (p<0.001, CI: -4.04, -1.23 and -3.82, -1.03, respectively) compared to CTRL. CoM-area in the ACL-groups did not differ from CTRL. CONCLUSIONS ACL-injured subjects demonstrated greater postural control efforts than CTRL but without significant differences in postural sway. Control efforts were thus not directly associated with sway and further research should be focused on variance in postural control strategies.

Knee kinematics during stair descent 20 years following anterior cruciate ligament rupture with and without reconstruction

BACKGROUND Changes and asymmetries for walking gait have been explored extensively following injuries of anterior cruciate ligaments within ten years of injury or reconstruction. We examined longer term knee joint kinematics of reconstructed and non-reconstructed knees during stair descent compared to controls. METHODS Three-dimensional knee kinematics during stair descent were registered for 33 subjects with ACL reconstruction, 36 subjects with ACL rupture managed with physiotherapy only and 31 uninjured controls. Injured subjects were 23.5 (2.1) years following injury. Linear mixed models were used to compare temporal variables and knee kinematics during stance phase between groups and contralateral sides. FINDINGS Walking speed was slower for the both ACL-injured groups compared to controls and stance duration was longer for the injured than the uninjured sides of the physiotherapy-only group. Compared to controls, the physiotherapy-only group had significantly less adduction at initial foot contact of the injured and uninjured knees. The uninjured side of the physiotherapy-only group also had less flexion than controls at initial foot contact and during weight acceptance. Compared to the surgically-managed group, the injured sides of the physiotherapy-only groups had significantly less adduction at initial contact, peak adduction during weight acceptance, and peak flexion during propulsion. INTERPRETATION Independent of treatment, altered knee kinematics exist more than 20 years following ACL injury during stair descent. We suggest that future studies investigating short and long-term kinematic outcomes of ACL injury could evaluate stair descent with particular emphasis on weight acceptance of stance, and potential associations to perceived knee function.

Curve analyses reveal altered knee, hip, and trunk kinematics during drop–jumps long after anterior cruciate ligament rupture

BACKGROUND Anterior cruciate ligament (ACL) ruptures may lead to knee dysfunctions later in life. Single-leg tasks are often evaluated, but bilateral movements may also be compromised. Our aim was to use curve analyses to examine double-leg drop-jump kinematics in ACL-reconstructed, ACL-deficient, and healthy-knee cohorts. METHODS Subjects with unilateral ACL ruptures treated more than two decades ago (17-28years) conservatively with physiotherapy (ACLPT, n=26) or in combination with reconstructive surgery (ACLR, n=28) and healthy-knee controls (n=25) performed 40-cm drop-jumps. Three-dimensional knee, hip, and trunk kinematics were analyzed during Rebound, Flight, and Landing phases. Curves were time-normalized and compared between groups (injured and non-injured legs of ACLPT and ACLR vs. non-dominant and dominant legs of controls) and within groups (between legs) using functional analysis of variance methods. RESULTS Compared to controls, ACL groups exhibited less knee and hip flexion on both legs during Rebound and greater knee external rotation on their injured leg at the start of Rebound and Landing. ACLR also showed less trunk flexion during Rebound. Between-leg differences were observed in ACLR only, with the injured leg more internally rotated at the hip. Overall, kinematic curves were similar between ACLR and ACLPT. However, compared to controls, deviations spanned a greater proportion of the drop-jump movement at the hip in ACLR and at the knee in ACLPT. CONCLUSIONS Trunk and bilateral leg kinematics during double-leg drop-jumps are still compromised long after ACL-rupture care, independent of treatment. Curve analyses indicate the presence of distinct compensatory mechanisms in ACLPT and ACLR compared to controls.

Increased movement variability in one-leg hops about 20 years after treatment of anterior cruciate ligament injury

Background Recent studies highlight the need for understanding movement control of adjacent joints when evaluating knee function following anterior cruciate ligament (ACL) injury. However, while short‐term adaptations to lower‐extremity joint coupling have been studied, little is known about any potential long‐term adaptations in neuromuscular control displayed by ACL‐injured individuals. The aim of our study was to determine whether coordination variability of the hip‐knee joint couplings during the one‐leg hop is altered about 20 years after injury in two ACL‐injured groups compared to healthy knee controls. Methods Seventy persons performed one leg hops ˜23 years after ACL injury and following different treatments: 33 participants treated with physiotherapy in combination with ACL‐reconstruction (ACLR); 37 participants with physiotherapy alone (ACLPT). They were compared to 33 matched controls. A vector coding procedure was used to create joint couplings for knee and hip angles on all the cardinal planes for the Take‐off and Landing phases. The standard deviation of each coupling was computed as a measure of coordination variability. Findings Both the ACL groups differed significantly from controls on their injured side with ˜50% higher knee abduction‐adduction/hip internal‐external rotation variability during the Take‐off phase; ˜33% higher knee abduction‐adduction/knee flexion‐extension variability and greater knee abduction‐adduction/hip flexion‐extension variability (ACLR 50%; ACLPT 80%) during the Landing phase. There were no major differences between injured and non‐injured sides in any group. Interpretation Increased variability in lower‐extremity joint couplings has emerged as a conspicuous feature of ACL injured persons in the very long term compared to non‐injured controls, independent of treatment. Further research of the processes leading to alterations in movement variability using longitudinal studies would facilitate better understanding of the functional adaptations leading to knee dysfunction in the short‐ and long‐term after ACL injury. HighlightsPotential long‐term (>20 yrs) movement adaptations following ACL injury are unknown.Hip‐knee joint coordination variability was assessed in one‐leg hop test.ACL reconstructed group, physiotherapy treatment group and control group were tested.Injured and non‐injured sides of both ACL groups did not exhibit any differences.Compared to controls, higher coordination variability was seen in both ACL groups.

A statistically compiled test battery for feasible evaluation of knee function after rupture of the Anterior Cruciate Ligament - derived from long-term follow-up data.

Purpose Clinical test batteries for evaluation of knee function after injury to the Anterior Cruciate Ligament (ACL) should be valid and feasible, while reliably capturing the outcome of rehabilitation. There is currently a lack of consensus as to which of the many available assessment tools for knee function that should be included. The present aim was to use a statistical approach to investigate the contribution of frequently used tests to avoid redundancy, and filter them down to a proposed comprehensive and yet feasible test battery for long-term evaluation after ACL injury. Methods In total 48 outcome variables related to knee function, all potentially relevant for a long-term follow-up, were included from a cross-sectional study where 70 ACL-injured (17–28 years post injury) individuals were compared to 33 controls. Cluster analysis and logistic regression were used to group variables and identify an optimal test battery, from which a summarized estimator of knee function representing various functional aspects was derived. Results As expected, several variables were strongly correlated, and the variables also fell into logical clusters with higher within-correlation (max ρ = 0.61) than between clusters (max ρ = 0.19). An extracted test battery with just four variables assessing one-leg balance, isokinetic knee extension strength and hop performance (one-leg hop, side hop) were mathematically combined to an estimator of knee function, which acceptably classified ACL-injured individuals and controls. This estimator, derived from objective measures, correlated significantly with self-reported function, e.g. Lysholm score (ρ = 0.66; p<0.001). Conclusions The proposed test battery, based on a solid statistical approach, includes assessments which are all clinically feasible, while also covering complementary aspects of knee function. Similar test batteries could be determined for earlier phases of ACL rehabilitation or to enable longitudinal monitoring. Such developments, established on a well-grounded consensus of measurements, would facilitate comparisons of studies and enable evidence-based rehabilitation.

Analysis of three-dimensional knee kinematics during stair descent two decades post-ACL rupture – Data revisited using statistical parametric mapping

Changes in movement patterns following knee injuries have generally used analyses of pre-defined discrete event-related variables, whereas Statistical Parametric Mapping (SPM) assesses continuous data over time. We applied SPM to test differences for knee trajectories during stair descent between participants with past anterior cruciate ligament (ACL) rupture who underwent reconstruction or only physical therapy compared to healthy controls. Three-dimensional knee joint kinematics during stair descent were registered for 31 subjects with ACL reconstruction (ACLR), 36 subjects with ACL rupture managed with physical therapy only (ACLPT) (∼23years post-injury), and 32 uninjured controls. SPM was used to assess differences between groups for the entire three-component knee trajectory. A significant difference between the three groups was found for the first ∼10% of stance phase. Post-hoc analyses showed between-group differences when comparing the ACLPT to the control groups. Analyses of ACLPT versus control groups for individual vector components suggested a combination of less flexion at initial foot contact, and less adduction during weight acceptance (∼40% of stance). Altered knee kinematics were confirmed during weight acceptance of stair descent for the ACLPT group compared to controls, but not for ACLR group. Further exploration of the use of SPM and agreement with clinical gait assessment is warranted.