Aims. To fully quantify the effect of posterior tibial slope (PTS) angles on joint kinematics and contact mechanics of intact and
Introduction. Unicompartmental knee arthroplasty(UKA) has become a popular treatment alternative when one compartment of the knee is affected. Excellent intermediate results have been reported in association with the Miller-Galante unicompartmental implant. These excellent results are based on the development of the implants and the stringent patients selection. The functional cruciate ligaments has been a prerequisite for patients undergoing UKA. However, UKA can be one of the procedures in elderly patiants with deficient
Anterior tibial translation (ATT) is assessed in the acutely injured knee to investigate for ligamentous injury and rotational laxity. Specifically, there is a growing recognition of the significance of anterior medial rotary laxity (AMRI) as a crucial element in assessing knee stability. Anterior cruciate ligament (ACL) injuries are often accompanied with medial collateral ligament (MCL) damage. It has been suggested that Deep MCL (dMCL) fibres are a primary restraint in rotational displacement. This research aims to quantify the difference in rotational laxity of patients with ACL and MCL injuries to deem if the Feagin-Thomas test can robustly capture metrics of AMRI. 2. AMRI was assessed using the Feagin-Thomas test in 7 isolated ACL (iACL) injured participants, 3 combined ACL and superficial fibre MCL (sMCL) injuries, 5 combined ACL and deep fibre MCL injuries, and 21 healthy controls. Displacement values were recorded using an optical motion capture (OMC) system and bespoke processing pipeline which map and model the knee's anterior displacement values relative to the medial compartment. Since absolute values (mm) of rotational laxity vary dependant on the person, values were recorded as a proportion of the rotational laxity obtained from the subject's contralateral leg. Values were compared between each patient group using an ANOVA test and Tukey's honesty significant difference post hoc test. 3.Introduction
Methods
To investigate changes in quadriceps and hamstrings muscle groups during sustained isokinetic knee flexion and extension. 125 paediatric participants (45 males and 80 females, mean age 14.2 years) were divided into two groups: participants with a confirmed ACL tear (ACLi, n = 64), and puberty- and activity-level matched control participants with no prior history of knee injuries (CON, n = 61). Participants completed a series of 44 repetitions of isokinetic knee flexion and extension at 90 deg/ sec using a Biodex dynamometer (Biodex Medical Systems Inc, Shirley, New York). Surface EMG sensors (Delsys Incorporated, Natick, MA) simultaneously recorded the quadriceps and hamstring activations. Muscle function was assessed as the change in quadriceps activation and extension torque were calculated using the percent difference between the mean of the first five trials, and the mean of the last five trials. ACLi participants had significantly higher percent change in quadriceps activation for both healthy and injured legs, in comparison to CON dominant leg. As such, the healthy leg of the ACLi participants is activating significantly more than their health matched controls, while also demonstrating reduced muscular endurance (less torque in later repetitions). Therefore, we conclude that the non-injured limb of the ACLi participant is not performing as a healthy limb. Since return to activity clearance following ACLi implies return to sport against age- and activity matched opponents, clearing young athletes based on the non-injured contralateral limb may put them at greater risk of reinjury.
To investigate differences in the drop vertical jump height in female adolescents with an ACL injury and healthy controls and the contribution of each limb in this task.
Forty female adolescents with an ACL injury (ACLi, 15.2 ± 1.4 yrs, 164.6 ± 6.0 cm, 63.1 ± 10.0 kg) and thirty-nine uninjured (CON, 13.2 ± 1.7 yrs, 161.7 ± 8.0 cm, 50.6 ± 11.0 kg) were included in this study. A 10-camera infrared motion analysis system (Vicon, Nexus, Oxford, UK) tracked pelvis, thigh, shank, and foot kinematics at 200Hz, while the participants performed 3 trials of double-legged drop vertical jumps (DVJ) on two force plates (Bertec Corp., Columbus, USA) sampled at 2000Hz.The maximum jump height normalised by dominant leg length was compared between groups using independent samples t-test. The maximum vertical ground reaction force (GRFz) and sagittal ankle, knee and hip velocities before take-off were compared between limbs in both groups, using paired samples t-test.
The normalised jump height was 11% lower in the ACLi than in the CON (MD=0.04 cm, p=0.020). In the ACLi, the maximum GRFz (MD=46.17N) and the maximum velocities of ankle plantar flexion (MD=79.83°/s), knee extension (MD=85.80°/s), and hip extension (MD=36.08°/s) were greater in the non-injured limb, compared to the injured limb. No differences between limbs were found in the CON. ACL injured female adolescents jump lower than the healthy controls and have greater contribution of their non-injured limb, compared to their injured limb, in the DVJ task. Clinicians should investigate differences in the contribution between limbs during double-legged drop vertical jump when assessing patients with an ACL injury, as this could help identify asymmetries, and potentially improve treatment, criteria used to clear athletes to sport, and re-injury prevention.
To investigate if the countermovement jump height differs between ACL injured and uninjured female adolescents and to explore kinematic differences between limbs. Additionally, the association between isometric knee extension strength and jump height was investigated. Thirty-one ACL injured female adolescents (ACLi, 15.3 ± 1.4yrs, 163.9 ± 6.6cm, 63.0 ± 9.3kg) and thirty-eight uninjured (CON, 13.2±1.7yrs, 161.7 ± 8.1cm, 50.6 ± 11.1kg) participated in this study. All participants performed a countermovement jump task, with 3D kinematics collected using a motion analysis system (Vicon, Nexus, Oxford, UK) at 200Hz, and a maximum isometric knee extension task on an isokinetic dynamometer (Biodex Medical Systems, New York, USA) for three trials. The peak torque was extracted from the isometric trials. Independent samples t-test compared the maximum jump height normalised by the dominant leg length between groups, paired samples t-test compared the maximum hip and knee extension and ankle plantar flexion velocities before take-off between limbs in both groups, and a Pearson's correlation test investigated the association between the isometric knee extension strength and jump height. The ACLi jumped 13% lower compared to the CON (p=0.022). In the ACLi, the maximum hip and knee extension and ankle plantar flexion velocities were greater in the non-injured limb, compared to the injured limb; however, no differences between limbs were found in the CON. The isometric knee extension strength of both limbs was positively correlated with jump height (limb 1: r=0.329; p=0.006, and limb 2: r=0.386; p=0.001; whereas limb 1 corresponds to the ACLi injured limb and CON non-dominant limb, and limb 2 to the ACLi non-injured limb and CON dominant limb). ACL injured female adolescents present lower jump height than controls and greater contribution of their non-injured limb, compared to their injured limb, during a countermovement jump task. Also, current results indicate that jump height is positively related to isometric knee extension strength measure.
To test the hypothesis that reseeded anterior cruciate ligament (ACL)-derived cells have a better ability to survive and integrate into tendon extracellular matrix (ECM) and accelerate the ligamentization process, compared to adipose-derived mesenchymal stem cells (ADMSCs). Acellularized tibialis allograft tendons were used. Tendons were randomly reseeded with ACL-derived cells or ADMSCs. ACL-derived cells were harvested and isolated from remnants of ruptured ACLs during reconstruction surgery and cultured at passage three. Cell suspensions (200 µl) containing 2 × 106 ACL-derived cells or ADMSCs were prepared for the purpose of reseeding. At days 1, 3, and 7 post-reseeding, graft composites were assessed for repopulation with histological and immunohistochemical analysis. Matrix protein contents and gene expression levels were analyzed.Aims
Methods
Appropriate soft tissue balance is an important factor for postoperative function and long survival of total knee arthroplasty(TKA). Soft tissue balance is affected by ligament release, osteophyte removal, order of soft tissue release, cutting angle of tibial surface and rotational alignment of femoral components. The purpose of this study is to know the characteristics of soft tissue balance in ACL deficient osteoarthritis(OA) knee and warning points during procedures for TKA. We evaluated 139 knees, underwent TKA (NexGen LPS-Flex, fixed surface, Zimmer) by one surgeon (S.A.) for OA. All procedures were performed through a medial parapatellar approach. There were 49 ACL deficient knees. A balanced gap technique was used in 26 ACL deficient knees, and anatomical measured technique based on pre-operative CT was used in 23 ACL deficient knees. To compare flexion-extension gaps and medial- lateral balance during operations between the two techniques, we measured each using an original two paddles tensor (figure 1) at 20lb, 30lb and 40lb, for each knee at a 0 degree extension and 90 degree flexion. We measured bone gaps after removal of all osteophytes and cutting of the tibial surface, then we measured component gaps after insertion of femoral components. Statistical analysis was performed by t-test with significant difference defined as P<0.05.INTRODUCION
METHODS
In 1994, 62% of the injuries were sustained during soccer and rugby, in 2004 58%. In 1994, 9% of injuries were sustained during skiing, in 2004 28% – a 300% increase. In 1994 the average age was 26.5, in 2004 33. When this increase was examined in detail the average age of the skiers was 41, the soccer players 31 and the rugby players 27. Clearly there has been a change in the demographics of ACL injury which may have a significant impact in providing NHS services for the ACL injured patient in the UK.
Ligament fibroblasts must be mechanosensitive and possess sufficient adaptability to a novel mechanomilieu ensuring the permanent load capacity of the tissue. Once mechanoreceptors are activated, the fibroblasts react with a specific signal transmission (mechanotransduction), which ultimately leads to an adaption of their cytoskeletal organization and protein synthesis. However, the cellular response of anterior cruciate ligament (ACL) fibroblasts to cyclic mechanical stretching is still unclear. Hence, this study should allow a deeper understanding of the reaction profile of mechanically stretched ACL cells in two- (2D) and three-dimensional (3D) biomaterial-free and biomaterial cultures with respect to cell survival, size, orientation, migration and distribution. For the 2D approach consisting of monolayers with 6000 lapine (L) ACL cells per cm2 and for the 3D cultures using preformed LACL cell spheroids (2.5–4/cm2) with 25.000 cells per spheroid, silicone chambers were coated with geltrex and statically colonized with the LACL cells for 24 h before cyclically stretched for 48 h (14 percent uniaxial stretch). A second approach using 3D scaffold cultures was performed which were seeded dynamically for 24 h with LACL cells before cyclically stretched in a novel custom-made mechanostimulator. The scaffolds [polylactic acid (PLA) and polycaprolactone (PCL)] were functionalized with 10 percent gas fluorination and a collagen foam. Scaffolds (120 mm2) were precolonized dynamically with an LACL cell suspension (1 mio cells/mL) for 24 h before stretched for 72 h (4 percent uniaxial stretch). Cell vitality and numbers were monitored. The cytoskeleton orientation was shown by cytochemistry (F-actin) and evaluated (ImageJ). Cell proliferation, based on the DNA content was measured. Cell viability in stretched samples (2D, 3D and scaffold) remained above 90 percent. Stretching on the silicone chambers led to increased cell counts, length and significantly higher colonized areas than in unstretched controls. Higher numbers of LACL cells migrated out of the 3D spheroids under stretching conditions. In response to intermittent stretching, cells oriented in a 70 degrees' angle against the stretch direction in silicone chambers, whereas cell arrangement was more compact on the threads of the scaffolds than in unstretched cultures. In summary, stretching induced a rapid (48 h) cell and cytoskeletal alignment in 2D as well as in 3D cultures. The natural ACL is characterized by a strongly uniaxial cell and extracellular matrix organization which might be achieved in tissue engineered constructs by a suitable cyclic stretching protocol in future.
Cultured primary cells have a limited life span and undergo dedifferentiation. Tissue engineering (TE) approaches require high cell numbers, but availability of human derived cells is limited and animal cells show inter-species differences. The advantages of immortalized cells are delayed senescence and phenotypic stability. The present study was undertaken to validate key properties of immortalized human anterior cruciate ligament (ACL) fibroblasts in direct comparison with non-immortalized cells from the same donor to assess their applicability as TE model. Human ACL ligamentocytes (40 years old female donor) were either immortalized using repeated transient transfection with a simian virus SV40 plasmid or remained untreated. Both cell populations were analyzed for cell survival, DNA content, tendon marker, extracellular matrix (ECM) and cytoskeletal protein expression. Cell spheroids of both populations were seeded on scaffolds embroidered either from polylactic acid (PLA) threads alone or combined PLA- and PLA-co-caprolacton-(P(LA-CL)) threads, functionalized with fluor treatment and collagen foams. Cell survival on the scaffolds was monitored for up to 5 weeks. In contrast to non-immortalized ligamentocytes, immortalized cells reflected some chaotic and incomplete cell divisions, higher DNA content, numbers of dying cells and nucleoli, reduced vimentin and vinculin-associated focal adhesions. Analysed markers, other cytoskeletal and ECM components were similarly expressed. Compared to the non-immortalized ligamentocytes immortalized formed instable spheroids and died on the scaffolds after 21 d. Both cell populations reflected superior growth on the PLA-P(LA-CL) compared with PLA scaffolds. Immortalized cells share crucial properties with their non-immortalized counterparts, but TE is only possible for limited culturing periods.
There is a challenge to detect partial tear of the ACL, the number of bundle injured and the proportion of fibers torn. The MRI was shown efficient to individualize the two anteromedial (AM) and posterolateral (PL) bundles of the ACL. The purpose of this study was to assess the ability of the MRI to detect partial tears of the ACL on axial views to display the AM and PL bundles. This retrospective study included 48 patients (19 partial tears of the ACL, 16 complete rupture of the ACL and 13 normal knee) who underwent both arthroscopy and MRI examinations of the knee. The conventional MRI protocol included one sagittal T1- weighted sequence and 3 proton-density fat sat. The images from MRI were analysis by a radiologist specialized in musculoskeletal imaging who was blinding to the arthroscopic findings. The criteria for the analysis of MRI were divided into primary (those involving the ACL himself) and secondary signs (associated abnormalities). The primary signs included the horizontalisation of the ACL (ACL axis), the global ACL signal intensity and the signal intensity of each AM and PL bundle. The secondary signs included bone bruise, osteochondral impaction, popliteus muscle injury, medial collateral ligament injury and joint effusion. The ACL was classified as normal, partially or totally torn. The rupture of the AM and PL bundle was specified.Introduction
Materials and methods
Injuries of the meniscal attachments can lead to meniscal extrusion. We hypothesized that the extent of lateral meniscal extrusion (LME) was associated with the severity of the lateral meniscus posterior root tear (LMPRT). This study aimed to evaluate the relationship between preoperative LME and arthroscopic findings of LMPRT in knees with anterior cruciate ligament (ACL) injury. Thirty-four knees that had LMPRTs with concomitant ACL injuries on arthroscopy were evaluated. Patients were divided into two groups, partial and complete root tears, via arthroscopic findings at the time of ACL reconstruction. We retrospectively measured preoperative LMEs using magnetic resonance imaging (MRI). Statistical analysis was performed using the Mann-Whitney U-test and Chi-square test.Purpose
Methods
This prospective case-controlled study evaluates the outcome of chronic combined anterior cruciate ligament (ACL) &
posterolateral corner (PLC) knee reconstruction. Twenty-six patients (23 male) underwent combined ACL &
PLC reconstruction between October 2001 and October 2006 (Group ACL/PLC). Mean age 30.2 years (range 17–44). Mean follow-up 51 months (range 27–109). The commonest mode of injury was football. Seven patients had concomitant lateral, and 9 medial meniscal procedures, 1 osteochondral defect was micro-fractured. All procedures were performed at the same operation. Prospective scoring was done pre-operatively and 3,6,12, and 24 months post-op using Lysholm, IKDC 2000 and KOOS scoring systems. These scores were compared to an age, sex and injury matched control group of patients who also underwent ACL reconstruction without posterolateral corners injury (Group ACL). Functional scores showed a significant improvement in all patients in both ACL/PLC and ACL groups postop (p<
0.05). Pre-op scores for Lysholm (p=0.005), IKDC (p=0.03), KOOS sports (p=0.03) and quality of life (QOL) (p=0.03) were significantly lower in Group ACL/PLC compared to Group ACL. Other significantly reduced KOOS scores were - sports 12 (p=0.04) &
24 months (p=0.004); and QOL 12 (p=0.01) &
24 months (p=0.006).
The aim of this study was to investigate the outcome after ACL reconstruction between a group of patients receiving a standardized supervised physiotherapy guided rehabilitation program and a group of patients who followed an un-supervised, home-based rehabilitation program. 40 patients with isolated anterior cruciate ligament injuries were allocated to either a supervised physiotherapy intervention group or home-based exercise group. Patients were investigated by an independent examiner pre-operative, 3, 6, 9 and 12 months post-surgery using the following outcome measures: Lysholm Score and Tegner Activity Scale, functional hopping tests, isometric and isokinetic strength assessments.Background:
Methods:
All professional athletes in this series and all athletes participating in high-level competitions were able to resume their former sports activity at the same level; for the entire series 67% resumed their former sports activities at the same level. Thirty-eight competition level athletes (n=63, 60%) resumed competition after surgery, 24 (38%) practised leisure sports. The change to leisure sports in these 24 patients was related to the knee plasty in eight. Irreducible knee flexion (+5°) was related to reflex dystrophy in four patients. Eleven patients presented reflex dystrophy; two had mobilisation under general anaesthesia. None of the patients had a painful harvesting site. Among the four cases with lateral decoaptation, two were related to poor dissection of the posterolateral angle without any pre-existing lesion of the peripheral formations. Section of the lateral intermuscular partition allowed complete closure of the fascia lata in all the difficult cases. We had only one case of proximal muscular herniation at the harvesting site.
The aim of this study was to compare the preinjury functional scores with the postinjury preoperative score and postoperative outcome scores following anterior cruciate ligament (ACL) reconstruction surgery (ACLR). We performed a prospective study on patients who underwent primary ACLR by a single surgeon at a single centre between October 2010 and January 2018. Preoperative preinjury scores were collected at time of first assessment after the index injury. Preoperative (pre- and post-injury), one-year, and two-year postoperative functional outcomes were assessed by using the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Score, and Tegner Activity Scale.Aims
Methods
Background. Return to sports after anterior cruciate ligament reconstruction (ACLR) is multifactorial and rotational stability is one of the main concerns. Anterolateral ligament reconstruction (ALLR) has been recommended to enhance rotational stability. Purpose. To assess the effect of ALLR on return to sports. Study Design. Retrospective comparative cohort study;. Level of evidence: III. Methods. A total of 68 patients who underwent ACLR after acute ACL injury between 2015 and 2018 with a follow-up of at least 24 months were enrolled in the study. Patients with isolated ACLR (group ALL(-), n=41) were compared to patients with ACLR+ALLR (group ALL(+), n=27) in regard to subjective knee assessment via Tegner activity scale,
Several studies have highlighted the relationship between