The objective of this study was to analyze the biomechanical effect of an implanted ACL graft by determining the tunnel position according to the aspect ratio (ASR) of the distal femur during flexion-extension motion. To analyze biomechanical characteristics according to the ASR of the knee joint, only male samples were selected to exclude the effects of gender and 89 samples were selected for measurement. The mean age was 50.73 years, and the mean height was 165.22 cm. We analyzed tunnel length, graft bending angle, and stress of the graft according to tunnel entry position and aspect ratio (ratio of antero-posterior depth to medio-lateral width) of the articular surface for the distal femur during single-bundle outside-in anterior cruciate ligament reconstruction surgery. We performed multi-flexible-body dynamic analyses with wherein four ASR (98, 105, 111, and 117%) knee models. The various ASRs were associated with approximately 1-mm changes in tunnel length. The graft bending angle increased when the entry point was far from the lateral
The purpose of this study is to investigate the three-dimensional (3D) kinematics of normal knees in deep knee-bending motions like squatting and kneeling. Material & Methods: We investigated the in vivo kinematics of 4 Japanese healthy male volunteers (8 normal knees in squatting, 7 normal knees in kneeling). Each sequential motion was performed under fluoroscopic surveillance in the sagittal plane. Femorotibial motion was analyzed using 2D/3D registration technique, which uses computer-assisted design (CAD) models to reproduce the spatial position of the femur and tibia from single-view fluoroscopic images. We evaluated the femoral rotation relative to the tibia and anteroposterior (AP) translation of the femoral sulcus and lateral
Abstract. Objectives. Neonatal motor development transitions from initially spontaneous to later increasingly complex voluntary movements. A delay in transitioning may indicate cerebral palsy (CP). The general movement optimality score (GMOS) evaluates infant movement variety and is used to diagnose CP, but depends on specialized physiotherapists, is time-consuming, and is subject to inter-observer differences. We hypothesised that an objective means of quantifying movements in young infants using motion tracking data may provide a more consistent early diagnosis of CP and reduce the burden on healthcare systems. This study assessed lower limb kinematic and muscle force variances during neonatal infant kicking movements, and determined that movement variances were associated with GMOS scores, and therefore CP. Methods. Electromagnetic motion tracking data (Polhemus) was collected from neonatal infants performing kicking movements (min 50° knee extension-flexion, <2 seconds) in the supine position over 7 minutes. Tracking data from lower limb anatomical landmarks (midfoot inferior, lateral malleolus, lateral knee
We describe a lateral approach to the distal humerus based on initial location of the superficial branches of the radial nerve, the inferior lateral cutaneous nerve of the arm and the posterior cutaneous nerve of the forearm. In 18 upper limbs the superficial branches of the radial nerve were located in the subcutaneous tissue between the triceps and brachioradialis muscles and dissected proximally to their origin from the radial nerve, exposing the shaft of the humerus. The inferior lateral cutaneous nerve of the arm arose from the radial nerve at the lower part of the spiral groove, at a mean of 14.2 cm proximal to the lateral
This study measured the three bony axes usually used for femoral component rotation in total knee arthroplasty and compared the accuracy and repeatability of different measurement techniques. Fresh cadaveric limbs (n=6) were used. Three observers (student, trainee and consultant) identified the posterior condylar (PCA), anteroposterior (AP) and the transepicondylar (TEA) axes, using a computer navigation system to record measurements. The AP axis was measured before and after being identified with an ink line. The TEA was measured by palpation of the
Summary Statement. Applying appropriate upper limb regional-specific and joint-specific tools along with suitable psychologic tools provides an effective assessment of supportive, interventional, and treatment strategies in TE. Background. Tennis elbow (TE) is a painful pathologic condition with its origin in the common wrist extensor muscles at the lateral
There are few studies that have compared between continuous flexion activities and extension activities of normal knees. The purpose of this study is to compare in vivo kinematic comparison of normal knees between flexion activities and extension activities. Total of 8 normal male knees were investigated. We evaluated in vivo three-dimensional kinematics using 2D/3D registration technique. We compared femoral rotation angle relative to tibia, anterior/posterior (AP) translation of medial femoral sulcus (medial side) and lateral femoral
Introduction. Lateral epicondylitis, also known as “tennis elbow,” is a degenerative disorder of the common extensor origin of the lateral humeral
Introduction. The stability of the elbow joint following an acute elbow dislocation is dependent on associated injuries. The ability to identify these concomitant injuries correctly directs management and improves the chances of a successful outcome. Interpretation of plain radiographs in the presence of either a dislocation or post-reduction films with plaster in-situ is difficult. This study aimed to assess the ability of orthopaedic registrars to accurately identify associated bony injuries on initial plain radiographs using CT as the gold standard for comparison. Methods. Patients over the age of 16 years undergoing an elbow CT scan within one week of a documented elbow dislocation between 1st June 2010 and 1st June 2014 were included in the study. Three orthopaedic registrars independently reviewed both the initial dislocation and immediate post reduction plain radiographs to identify any associated bony injuries. This radiograph review was repeated by each registrar after two weeks. The incidence of associated injuries as well as the inter- and intra-observer variability was calculated. Results. 28 patients were included in the study. 54% of the patients were female and the mean age was 45 years (range 16 to 90 years). The incidence of a radial head fracture was 54%, coronoid fracture 43% and
Background. The pattern of appearance of secondary ossification centers in the elbow has been based on historical studies and is popularly referred to with the mnemonic CRITOL. However the six secondary ossification centers can be variable in their presentation and pose a challenge in assessment of children with elbow injuries. Furthermore limited studies available in the current literature have reported an aberration to the sequence of appearance especially with the ossification centers of trochlea and olecranon. Aims. The aim of the study was to evaluate the relative sequence of appearance of secondary ossification centers for the trochlea and olecranon. Methods. Children between 8 and 10 years of age who had radiographs of elbow following trivial trauma between July 2013 and Feb 2015 were identified using the hospital PACS database. Cases with radiographic markers of significant trauma ie. fat pad sign, displaced fracture were excluded. Anteroposterior and lateral views of elbow were reviewed for the presence of the six ossification centers. Results. A total of 114 radiographs were reviewed of which 51 were boys and 63 were girls with a mean age of 9.03 years (±0.59). 60 radiographs were of right elbow and 54 were of the left elbow. The capitulum, radial head and medial
Introduction. The epicondylar axis of the elbow is a surface anatomical approximation of the true flexion-extension (F-E) axis used in the application of an external fixator/elbow arthroplasty. We hypothesise that the epicondylar axis coincides with the true F-E axis in terms of both angular displacement and position (ie. offset). This suggests that it can serve as a good landmark in total dynamic external fixator application and elbow arthroplasty. Methods. Three-dimensional elbow models were obtained through manual segmentation and reconstruction from 142±40 slices of CT scans per elbow in 15 cadeveric specimens. Epicondylar axis was defined to be the axis through the 2
The evaluation of knee stability is fundamental for the clinical discrimination between healthy and pathological joints, for the design and evaluation of prostheses and for the definition of articular models. Knee stability can be quantified by measuring the relation between applied single-axis constant loads and corresponding tibio-femoral displacements (i.e., translations and rotations), namely the joint stiffness, at a given flexion angle. No many studies are available in the literature on this topic [1–3]. In particular, the translations/rotations along/about directions different from the loaded one were not deeply investigated. A fresh frozen lower-limb specimen (female, 63 years old, weight 68 Kg, height 158 cm) was considered. The forefoot and all soft tissues outside the knee were removed by a surgeon, keeping the knee joint capsule intact. A stereophotogrammetric system (Vicon Motion Systems Ltd.) was used to measure the femoro-tibial relative motion by two trackers fixed to the bones, thus introducing no soft-tissue artifact. The specimen was then mounted on a test rig capable to exert general loading conditions [4], and constant loads were applied to the tibia: ±100 N in antero-posterior (AP) and medio-lateral (ML) direction; ±10 Nm about abb-adduction (AA) and in-external (IE) rotations. Loads were applied approximately at the mid-point between the lateral and medial
Total knee replacements (TKR) have been the main choice of treatment for alleviating pain and restoring physical function in advanced degenerative osteoarthritis of the knee. Recently, there has been a rising interest in minimally invasive surgery TKR (MIS-TKR). However, accurate restoration of the knee axis presents a great challenge. Patient-specific-instrumented TKR (PSI-TKR) was thus developed to address the issue. However, the efficacy of this new approach has yet to be determined. The purpose of the current study was thus to measure and compare the 3D kinematics of the MIS-TKR and PSI-TKR in vivo during sit-to-stand using a 3D fluoroscopy technology. Five patients each with MIS-TKR and PSI-TKR participated in the current study with informed written consent. Each subject performed quiet standing to define their own neutral positions and then sit-to-stand while under the surveillance of a bi-planar fluoroscopy system (ALLURA XPER FD, Philips). For the determination of the 3D TKR kinematics, the computer-aided design (CAD) model of the TKR for each subject was obtained from the manufacturer including femoral and tibial components and the plastic insert. At each image frame, the CAD model was registered to the fluoroscopy image via a validated 2D-to-3D registration method. The CAD model of each prosthesis component was embedded with a coordinate system with the origin at the mid-point of the femoral
Osteoarthritis is a joint condition affecting an estimated eight million people in the UK. The kinematics of walking and the impact experienced are thought to play an important role in the initiation and progression of the disease. Previous studies have looked the effect of osteoarthritis on the kinematics of walking in a laboratory environment. This work is part of the Newcastle Thousand Families Study which has followed a cohort of 1142 members since birth in 1947. Optoelectronic gait analysis methods are unsuitable for this environment, so inertial measurement units are being used. This study focuses on the validation of a protocol using inertial sensors to assess gait in the clinical environment. The sensors measure orientation in three dimensions. Our hypothesis was that an attachment position that minimises the movement of the sensor relative to the segment during gait was more important than the proximity of the sensor to anatomical landmarks. The effect of sampling rate, fatty tissue movement and material type were also tested Seven sensors (Xsens, Netherlands) were attached to participants on top of the foot, on the tibial plateau, on the lateral surface of the femur 10cm proximal to the lateral
Whilst gait speed is variable between healthy and injured adults, the extent to which speed alone alters the 3D A total of 26 men and 25 women (18 to 35 years old) participated in this study. Participants walked on a treadmill with the KneeKG system at a slow imposed speed (2 km/hr) for three trials, then at a self-selected comfortable walking speed for another three trials. Paired Objectives
Methods
We investigated the effects on fracture healing of two up-regulators of inducible nitric oxide synthase (iNOS) in a rat model of an open femoral osteotomy: tadalafil, a phosphodiesterase inhibitor, and the recently reported nutraceutical, COMB-4 (consisting of L-citrulline, Paullinia cupana, ginger and muira puama), given orally for either 14 or 42 days. Unilateral femoral osteotomies were created in 58 male rats and fixed with an intramedullary compression nail. Rats were treated daily either with vehicle, tadalafil or COMB-4. Biomechanical testing of the healed fracture was performed on day 42. The volume, mineral content and bone density of the callus were measured by quantitative CT on days 14 and 42. Expression of iNOS was measured by immunohistochemistry.Objectives
Materials and Methods
The understanding of rotational alignment of the distal femur is essential in total knee replacement to ensure that there is correct placement of the femoral component. Many reference axes have been described, but there is still disagreement about their value and mutual angular relationship. Our aim was to validate a geometrically-defined reference axis against which the surface-derived axes could be compared in the axial plane. A total of 12 cadaver specimens underwent CT after rigid fixation of optical tracking devices to the femur and the tibia. Three-dimensional reconstructions were made to determine the anatomical surface points and geometrical references. The spatial relationships between the femur and tibia in full extension and in 90° of flexion were examined by an optical infrared tracking system. After co-ordinate transformation of the described anatomical points and geometrical references, the projection of the relevant axes in the axial plane of the femur were mathematically achieved. Inter- and intra-observer variability in the three-dimensional CT reconstructions revealed angular errors ranging from 0.16° to 1.15° for all axes except for the trochlear axis which had an interobserver error of 2°. With the knees in full extension, the femoral transverse axis, connecting the centres of the best matching spheres of the femoral condyles, almost coincided with the tibial transverse axis (mean difference −0.8°,
Anatomical descriptions of the lateral retinaculum have been published, but the attachments, name or even existence of its tissue bands and layers are ill-defined. We have examined 35 specimens of the knee. The deep fascia is the most superficial layer and the joint capsule is the deepest. The intermediate layer is the most substantial and consists of derivatives of the iliotibial band and the quadriceps aponeurosis. The longitudinal fibres of the iliotibial band merge with those of the quadriceps aponeurosis adjacent to the patella. These longitudinal fibres are reinforced by superficial arciform fibres and on the deep aspect by transverse fibres of the iliotibial band. The latter are dense and provide attachment of the iliotibial band to the patella and the tendon of vastus lateralis obliquus. Our study identifies two important new findings which are a constant connection of the deep fascia to the quadriceps tendon superior and lateral to the patella, and, a connection of the deeper transverse fibres to the tendon of vastus lateralis obliquus.
We have investigated the errors in the identification of the transepicondylar axis and the anteroposterior axis between a minimally-invasive and a conventional approach in four fresh-frozen cadaver knees. The errors in aligning the femoral prosthesis were compared with the reference transepicondylar axis as established by CT. The error in the identification of the transepicondylar axis was significantly higher in the minimal approach (4.5° of internal rotation,
A cadaver study using six pairs of lower limbs was conducted to investigate the accuracy of computer navigation and standard instrumentation for the placement of the Birmingham Hip Resurfacing femoral component. The aim was to place all the femoral components with a stem-shaft angle of 135°. The mean stem-shaft angle obtained in the standard instrumentation group was 127.7° (120° to 132°), compared with 133.3° (131° to 139°) in the computer navigation group (p = 0.03). The scatter obtained with computer-assisted navigation was approximately half that found using the conventional jig. Computer navigation was more accurate and more consistent in its placement of the femoral component than standard instrumentation. We suggest that image-free computer-assisted navigation may have an application in aligning the femoral component during hip resurfacing.