SUMMARY The aim of the study was to evaluate the effectiveness of physical therapy after anterior cruciate ligament repair using different grafts. The goals of the study: to evaluate a functional state of the knee joint (according to Lysholm knee scale), to evaluate the knee joint motions’ amplitude at different physical therapeutics stages (6 weeks, 3 months and 7 months after the surgery), to compare the influence of different methods used in reconstructive surgeries on the rehabilitation of the knee joint’s functions. Organization and methods of the study. Two groups of patients underwent examination. 28 patients ( 15 men and 13 women) underwent anterior cruciate ligament repair where the semitendinosus and gracilis tendon graft (SG) was used . The second group, 23 patients, ( 14 men and 9 women) underwent anterior cruciate ligament repair where patella ligament (PL) was used. Examination of the patients was performed 6 weeks, 3 months and 7 months after the surgery. Every time the Lysholm knee scale was used and range of motions of the knee was estimated. The both groups of patients underwent the same physical therapy programme. Results. While evaluating a function of the knee joint (according to Lysholm knee scale) after 6 weeks and 3 months after the surgery , a statistically reliable difference between the groups concerning pain was established (p<0,05). There were found more patients in the PL group who suffered pain in the knee joint. While... [to full text]

Background: Semitendinosus-gracilis (STG) autograft continues to increase in ACL reconstruction and a comprehensive study of the impact of what is essentially ‘surgically induced tenotomy’ of STG has not been undertaken. Purpose: To examine longitudinal changes in muscle morphometry and physical activity (PA) in relation to strength, functional tests, and subjective outcomes. Methods: Assessments at pre-, 2-weeks, 6- and 12-months post-surgery were performed on twenty moderately active adults undergoing ACL reconstruction. Participants were randomized to the Standard group (using STG tendon from the ACL deficient limb) or the Contra group (using STG from the opposite limb). Bilateral lower extremity MRI, Tegner, Lysholm, and IKDC scores, hop tests, and isovelocity strength testing in a seated and hipneutral supine position were completed. PA was assessed using a tri-axial accelerometer (GTX3, Actigraph, Pensacola, FL). Results: Subjective scores significantly improved from pre- to 12-months post-surgery, although Tegner score was significantly less (-1.25 levels) than pre-injury scores at 12- months. ST and G CSA significantly declined in donor limbs to 41.5% and 65.5% of presurgery,respectively and there was a 5.7 (2.9) cm proximal shift in ST and a 4.2 (2.3) cm shift in G donor muscles. In the donor limb, nine of 17 participants for ST and one for G had more than an 80% reduction in volume. There was significant difference between donor and non-donor limbs in peak knee flexor torque, but only in the hip-neutral testing position. There were no differences in hop tests between legs regardless of reconstruction or STG tendon harvest. PA did not significantly improve from pre-surgery, but was comparable an age-matched normative population. This level was less than that necessary for a healthy lifestyle (10,000 steps). Morphological parameters were moderately or highly predictive of outcomes in subjective findings, single hop test, PA, and strength. Conclusion: Changes in muscle morphology following tendon harvest of ST and G were found to be related to measured decreases in knee flexor strength, and post-operative deficiencies in objectively measured PA, hop tests, and subjective findings at 12-months post-surgery. PA did not increase in a statistically or clinically relevant degree consistent with a diminished self-report of function.

Background: Knee injuries have a considerable impact on both the person’s psychological and physical health. We currently have tools to address each of these aspects but they are often considered independent of each other. Little work has been done to consolidate the subjective and objective functional ability of anterior cruciate ligament (ACL) injured individuals, which can be detrimental when implementing a return-to-play decision-making scheme. The lack of understanding concerning the relationship of these two measures may account for the high incidence of re-injury rates and lower quality of life exhibited by so many of these patients. Purpose: The purpose of this doctoral thesis is to investigate the relationship between subjective and objective measures of functional ability in ACL deficient and ACL reconstructed conditions through biomechanical and neuromusculoskeletal modelling approaches. Methods: This thesis is comprised of five studies based on a single in vivo data collection protocol, medical imaging and in silico data analyses. The in vivo data collection was of test-retest design where ACL deficient patients participated prior to their operation and approximately ten months post-reconstruction. This experimental group was matched to a healthy, uninjured control group, which was tested a single time. The first study of this thesis involved a descriptive analysis of spatiotemporal, neuromuscular, and biomechanical patterns during hopping and side cut tasks in addition to subjective functional ability questionnaires. Then, two novel measures of dynamic knee joint control were developed and applied along with a third measure to determine if changes in joint control exist between the three groups (Study 2). The relationships of these objective measures of functional ability to subjective measures were then examined through correlation and regression models (Study 3). Following this, a method of including magnetic resonance imaging to construct patient-specific models was developed and implemented to determine realistic kinematic and ligament lengthening profiles (Study 4). These patient-specific models were then applied to quantify knee joint loading in the form of contact and ligament forces, which were correlated to subjective measures of functional ability (Study 5). Results: Even though no major differences in neuromuscular patterns were observed between all three groups, it was found that subjective patient-reported outcome measures scores and biomechanical measures in the form of knee flexion angles and extensor moments were lower in the ACL deficient group compared to healthy controls. These differences continued to exist 10 months post-operation as the ACL reconstructed group had not fully recovered to patterns observed in the healthy controls. The current findings also suggest a possible hierarchy in the relationships between objective and subjective measures of functional ability. Basic kinematic objective measures such as knee flexion angle show small to moderate correlations, while more comprehensive measures such as stiffness and joint compressive force show moderate to strong correlations to subjective questionnaires. Finally, this thesis developed patient-specific OpenSim models that were used to produce appropriate kinematics and ligament lengthening with the reduction in soft tissue artefact. Conclusion: This thesis demonstrated that patients who are high-functioning in the ACL deficient state show greater improvements in subjective outcome scores after ACL reconstruction compared to objective measures. Biomechanical and neuromusculoskeletal modelling approaches identified important differences between the healthy and ACL deficient groups that were not resolved post-operatively. Our results also demonstrate that certain subjective and objective measures of functional ability are strongly correlated. The knowledge gained from this test-retest design and novel patient-specific in silico models aids clinicians in managing their expectations regarding the effectiveness of reconstruction and the respective long-term sequelae.

Purpose: Pediatrics and adolescents are at a higher risk to suffer an anterior cruciate ligament (ACL) injury in comparison to their adult counterparts. As well, the rate of injury is increasing. While some of this increased injury rate may be attributed to increased participation in sport, it remains unknown why only some children suffer an ACL injury. Traditionally, surface marker- based motion-capture would be used to determine this difference; however, due to the presence of soft tissue artifact, marker translation may exceed the physiological range of the knee itself. Using OpenSim, the range of motion of the knee was constrained to allow for soft tissue artifact to be reduced. Therefore, the two objectives of this thesis are 1) to create and validate a new OpenSim knee model, and 2) to use this knee model to determine whether differences in knee kinematics and ligament lengths exist between ACL injured and non-injured control pediatrics. Methods: Manuscript 1 (Chapter 5), focused on the first objective of creating and validating a new OpenSim knee model. Thirty-two healthy pediatric females performed squats, countermovement jumps, and drop-vertical jumps. OpenSim models were made and scaled to each participant and featured a 6-degree-of-freedom knee. Each knee was allowed to move in a manner dictated by published in vivo biplanar fluoroscopy studies. These resultant biplanar fluoroscopy-constrained knee kinematics were then compared to another series of in vivo constraints: bone pin-constrained kinematics. Finally, the length of the four main ligaments of the knee were tracked and compared to existing literature on healthy ligament lengths from extension to deep flexion. Manuscript 2 (Chapter 6) sought to answer the second question: Are there differences in kinematics and ligament lengths between ACL-injured and uninjured control participants? Forty ACL-injured (20 male, 20 female) and 40 uninjured control (20 male, 20 female) participants completed a countermovement jump, which drove inverse kinematics for the OpenSim model created in Manuscript 1. Knee kinematics and ligament lengths were compared between male injured to male control, and female injured were compared to female control. To isolate the effect of injury, males were not compared to females. Results: Starting with Manuscript 1, the squat task had the best agreement between biplanar fluoroscopy and bone pin kinematics, during periods of low knee flexion. At high flexion, the ACL length was shorter than literature data, for all tasks. For Manuscript 2, during the countermovement jump, female control participants obtained greater knee flexion and internal rotation when compared to female ACL-injured participants. For males, there were only small differences in countermovement jump kinematics. For ligament lengths, female controls had longer posterior cruciate ligament lengths, whereas for males, male ACL-injured participants presented with longer ligament lengths for all 4 ligaments. Conclusion: The thesis results identified how to use deep flexion biplanar fluoroscopy constraints to minimize soft tissue artifact. In comparison to previously established knee bone pin constraints, the biplanar fluoroscopy knee relied more on internal-external rotation and anterior-posterior translation to obtain the required bone positions in OpenSim. This additional anterior-posterior translation also led to the increased shortening of the ACL, as the linear distance between ligament insertion points decreased. Next, this thesis identified small differences in kinematics between ACL-injured and control pediatric females during a countermovement jump, where control participants obtained greater knee flexion in the preparatory and landing phase of the task. Few differences in kinematics were found in males. Differences in ligament lengths between injured and control groups were based on differences in knee kinematics, or by participant anthropometrics; taller participants had longer ligaments.

Introduction: Anterior cruciate ligament (ACL) injuries are the most common ligamentous injury in the adolescent knee, resulting in long-term health consequences including early onset knee osteoarthritis and a high predominance of re-injury. The current ACL rehabilitation measures need improvement, in particular for adolescents. Information surrounding energy absorption strategies during demanding tasks may provide important insight into functional capacity and movement quality and could be a variable that is considered in ACL rehabilitation programs. The purpose of this thesis was therefore to evaluate energy absorption strategies in adolescent males and females with and without ACL injuries. Specifically, to first identify sex and injury status differences in lower extremity kinematics and kinetics in adolescent males and females with and without an ACL injury, and then secondly, determine if there is a generalizable relationship between strength and energy absorption strategies within these populations during drop-vertical jumps. Methods: Fifty-two ACL injured (17 males) and 68 control adolescent (34 males) males and females between the ages of 10 and 18 performed five trials of a lunge and drop vertical jump (DVJ) task. Ankle plantarflexion, and knee extension and flexion maximum voluntary isometric contractions (MVIC) were collected, along with 3D kinematics and kinetics including joint angles, joint moments, and energy absorption at the hip, knee, and ankle joint. Two-way analyses of variance (ANOVA), statistical non-parametric mapping (SnPM), and multiple linear regressions were used to determine statistically significant differences and relationships in joint kinematics, kinetics, and MVIC's between the male and female ACL injured and control individuals. Results: Males displayed greater knee extension torque compared to females, while controls displayed greater knee extension and ankle plantarflexion torque compared to ACL injured. There were no energy absorption differences found during the DVJ, however, during the lunge male controls display greater energy absorption compared to females. Furthermore, small effect sizes were found in the hip, knee, and ankle joint energy absorption for knee strength (knee extension or knee flexion), sex, and injury status. However, sex, injury status, and knee strength did not significantly add to the prediction of energy absorption. Conclusion: These findings indicate that isometric strength might be an important variable to be considered in ACL injury rehabilitation and injury prevention programs with injured individuals displaying weaker knee extension and ankle plantarflexion torques. However, energy absorption may not be as important of a variable to consider as there were limited statistically significant differences between injury status and sex at the hip, knee, and ankle joints. Additionally, there does not appear to be a generalizable relationship between hip, knee, and ankle energy absorption and knee flexion and extension isometric strength in male and female control and ACL injured individuals. Injured individuals absorb similar energy levels at each joint compared to controls, with isometric strength showing a weak relationship with energy absorption. Therefore, it is possible that there is not a specific energy absorption or muscular strength strategy that can be used to improve adolescent ACL rehabilitation measures.

No description available.

Syfte och frågeställningar Huvudsyftet med denna studie var att se om ett vertikalhopp eller ett trippelhopp uppvisade större känslighet att identifiera skillnader mellan opererat och icke-opererat ben i jämförelse med ett horisontalhopp hos individer som genomgått främre korsbands(ACL)-rekonstruktion. Studien syftade även till att undersöka om individens kön påverkade resultatet och om prestationen på de olika hoppen hade ett samband med isokinetisk benstyrka respektive det knäspecifika instrumentet KOOS, The Knee injury and Osteoarthritis Outcome Score. Metod 17 försökspersoner, 9 män och 8 kvinnor (medelålder 28 år) deltog i studien. De hade alla genomgått primär unilateral ACL-rekonstruktion i genomsnitt 7 månader tidigare. Vid ett och samma mättillfälle utfördes ett isokinetiskt styrketest samt tre funktionella hopp: vertikalhopp (”Jump and Reach”), trippelhopp samt horisontalhopp. KOOS fylldes i av försökspersonerna runt samma tidpunkt (nätbaserat frågeformulär för utvärdering av patientens upplevelse av sitt knä och knärelaterade besvär). Resultat Vertikalhoppet uppvisade en högre sensitivitet i jämförelse med horisontalhoppet vid test 7 månader efter ACL-rekonstruktion. Gällande de absoluta värdena (opererat ben) uppvisade både vertikalhoppet som trippelhoppet ett statistiskt samband med explosiv quadricepsstyrka (240grader/sekund), r=0,75 respektive r=0,73. Inget samband kunde ses mellan hopp och resultatet på KOOS. Inga könsskillnader hittades. Slutsats Resultaten visar att vertikalhoppet är ett mer sensitivt test för att identifiera funktionella nedsättningar i ACL-rekonstruerat knä i jämförelse med horisontalhoppet som ofta används som ”gold standard” i forskning och i den kliniska vardagen. En enkel och billig testmetod för vertikalhoppet, ”Jump and Reach” som användes i denna studie visar liknande resultat på sensitiviteten i jämförelse med datoriserade mätmetoder som är dyra och ofta inte tillgängliga i sjukgymnastens kliniska vardag.

Introduction: Understanding the relationship between muscle loads crossing the knee joint and knee joint mechanics is critical for understanding knee stability and the effects of altered muscle forces on healthy and ACL injured knees. In vitro measurement can be used to elucidate this if the simulation is biofidelic, allowing the physiological levels of applied loads to dictate the tibiofemoral kinematics in all degrees of freedom (DoF). The objectives of this study were to describe and apply the University of Ottawa knee simulator as well as measure the reliability of the device. In addition, this device was used to quantify the effect of muscle loads and anterior cruciate ligament (ACL) resection on contact mechanics and kinematics of the tibiofemoral joint. Methods: Muscle forces were determined from an electromyography-driven musculoskeletal model of a healthy male during gait. Six knee specimens were loaded into the simulator and subjected to 100%, 75% and 50% in vivo muscle forces applied through the 6 simulated muscles, in addition to a quadriceps weakness and a hamstring weakness condition. Tibiofemoral mechanics were measured with all 5 loading conditions before and after ACL transection. Results: With the ACL intact, very high reliability in contact area and pressures among loading conditions were observed as the intra-class correlation coefficients (ICC) ranged from 0.932 to 0.99. After ACL transection, reliability remained very high as ICCs ranged from 0.926 to 0.99. In all simulated conditions, muscle forces maintained the knee joint in a stable position resulting in minimal kinematic differences, but altered contact mechanics in both the ACL and non-ACL condition. Removal of the ACL significantly reduced both the medial and lateral contact areas in all loading conditions compared to the ACL intact condition. Conclusion: In summary, the UOKS has demonstrated high reliability within repeated measures. Additionally, small, normally undetectable alterations in joint kinematics resulted in significant alterations to contact mechanics, which can be linked to the degenerative process.

The mainstay of treatment for injuries to the anterior cruciate ligament (ACL) is with a tendon graft harvested from elsewhere in the knee. This procedure, known as ACL reconstruction (ACLR), has excellent reported outcomes in terms of restoring the gross stability of the knee. However there are reported rates of graft failure in the pediatric population.1 ACL reconstruction also does not provide full protection from developing premature osteoarthritis, which is often seen in patients after ACL injury. A new method must be found in order to find a solution to these adverse outcomes from the current standard treatment of ACL injuries. The Bridge-enhanced anterior cruciate ligament repair (BEAR) technique is a new innovation on primary repair of a torn ACL. It avoids the requirement for autograft harvesting and use of an allograft by combining a primary suture repair with an extraceullular matrix scaffold (the BEAR scaffold). This scaffold is placed between the two torn ends of the ACL to help facilitate natural healing of the ligament in order to restore the intrinsic functions of the ACL to protect the knee from trauma and instability. This ability to repair the native ACL maintains the proper anatomy of its insertion points, avoids donor site morbidity, and helps to prevent early osteoarthritis by maintaining innate proprioceptive functions of the ACL. Our study will prove the BRIDGE repair to be a promising step in the direction of preserving the native ACL.

Indiana University-Purdue University Indianapolis (IUPUI) / Leg-Spring Stiffness (LSS) is the measure of the musculoskeletal, neuromuscular, and biomechanical functions of the human body, and an appropriate evaluation metric for changes brought on by Anterior Cruciate Ligament Reconstruction (ACLr). ACLr can lead to flexion and extension loss, resulting in increased stiffness of the musculotendinous units of the ACLr leg and thus changes in LSS. LSS can be measured using Kleg, but little is known about the validity and reliability of the different methods of LSS and Kleg calculations. The purpose of this study was to determine if ACLr leads to a change in LSS (as measured by Kleg) during hopping, and to compare results of the Spring-Mass calculation and knee Joint Torsional stiffness methods in the computation of the overall Kleg. Video data synchronize with GRF were used to compute the kinematic and kinetic variables. Mann-Whitney U tests were used to determine significant differences between the control and experimental group for the Spring-Mass method of calculation (p = 0.004), Joint Torsional method (p =0.44), Kknee (p = 0.29), and Kankle (p = 0.17). Cohen’s effect calculations showed small to medium effects for the KKnee, (d = 0.383) but moderate effect size for the KAnkle, (d = 0.541). Wilcoxon Signed Rank comparison for all the legs and (N=42) between computational methods were significant differences between computational methods (Z = 5.65, p = 0.000), and with a large effect size (Cohen’s d = 3.14). Similar results were found when comparing only the ACLr leg values (p = 0.005, Cohen’s d = 4.88). The comparison between ACL Leg vs Non-ACL leg for experimental group subjects was not significant in either calculation method (Spring-Mass p = 0.20, Z = -1.27; torque calculation p = 0.96, Z = -0.05). The spring-mass method was more stable and able to detect differences between the control and ACLr group. The lack of statistical differences in the joint torsion calculation method, as well as in comparing the unaffected leg to the ACLr leg in the experimental group, suggests that LSS may not be a precise enough measurement to determine the effects of an ACLr.