Flexion Component Research Articles

One-Year Follow-Up Study on Assessing the Range of Segmental Motion and Clinical Outcomes Following Cervical Disc Arthroplasty for Treatment of Severe Cervical Disc Degeneration

Though previous studies have documented various clinical outcomes after cervical arthroplasty for degenerative cervical disc disease, none of them reported the impact of cervical arthroplasty on severe cervical disc degeneration (CDD). This retrospective cohort study included severe 40 CDD (C3-C7) patients who underwent single-level cervical arthroplasty using ProDisc-C between January 2017 and December 2019. After surgical intervention, the range of motion (ROM) was determined, whereas clinical outcomes were measured in terms of the Visual Analogue Scale (VAS) and Neck Disability Index (NDI) to evaluate neck pain and disability, respectively. Compared to the mean preoperative ROM (6.57 ± 4.85°), the cervical dynamic ROM was increased 3months after cervical arthroplasty, and the increment was maintained for at least 1year. The increased ROM is attributed to the extension and not flexion components. The mean preoperative ROM of 6.57 ± 4.85° significantly increased to 11.67 ± 4.98° (P= 0.0005), 10.05 ± 5.18° (P= 0.0426) and 10.46 ± 4.73° (P= 0.0247) after 3months, 6months and 1year, respectively. The extension ROM also revealed a similar trend. VAS for neck and arm decreased from 7.4 and 6.6 to 1.4 and 1.2, respectively. Consistently, the preoperative mean Neck Disability Index (NDI) score of 27.6 decreased to 14.6. We recorded a case of device subsidence, but without extrusion. Cervical arthroplasty can improve clinical outcomes and restore ROM in severe CDD patients.

New highly precise weak gravitational lensing flexions measurement method based on ERA method

ABSTRACT Weak gravitational lensing flexions are a kind of weak lensing distortion that are defined as the spin 1 and spin 3 combinations of the third order derivatives of gravitational lensing potential. Since the shear has spin 2 combination of the second-order derivative, the flexion signal gives partly independent information from shear signal and is more sensitive to the local mass distribution than shear signal. Thus its measurement is expected to play important roles in observational cosmology. However, since the weakness of the flexion signal, as well as the complicatedness of its intrinsic noise, made its accurate observation very difficult. We propose a new method of measuring the flexion signal using ERA method which is a method to measure weak lensing shear without any approximation. We find two particular combinations of the flexions which provide the quantities with only lensing information and free of intrinsic noise when taken average. It is confirmed by simple numerical simulation that the statistical average of these combinations do not in fact depend on the strength of the intrinsic distortion. Then, we introduce a method which measures flexions with PSF correction. This method is developed by applying the ERA method for flexion distortions and we call this method the FIRE method. It uses the expansion technique with an assumption of weak flexion, and we show by using typical examples of 1st and 2nd flexion images that the estimated errors become less than 1 per cent in most cases with the lowest order of the expansion. Finally, we apply the method for real data to measure flexion components in real galaxy images.

Differences in Muscle Quantity and Quality by HIV Serostatus and Sex.

People with HIV (PWH) experience greater declines in both muscle function and muscle mass with aging. Whether changes in muscle quality and quantity with aging differ between men and women with HIV and the implications on muscle function are not established. In coordinated substudies of the Multicenter AIDS Cohort Study and Women's Interagency HIV Study, participants completed physical function and falls assessments; total trunk/thigh density, inversely related to fatty infiltration, and area were quantified from computed tomography (CT) scans. Generalized linear models were used to explore variables affecting density/area, and associations between area/density and physical function and falls. CT scans were available on 387 men (198 PWH) and 184 women (118 PWH). HIV serostatus was associated with greater lateralis, paraspinal, and hamstring area, but lower psoas area and density. Older age and female sex were associated with smaller trunk muscle area and lower density. Both lower muscle area and muscle density were associated with several measures of impaired physical function. The odds of falling were lower with greater hamstring density, but not associated with other measurers of muscle area or density. In summary, older adults with HIV appear to have smaller and less dense (fattier) psoas, a key component in truncal stability and hip flexion that could have implications on physical function. The longitudinal associations of muscle area and density with physical function require careful investigation, with a particular focus on characteristics and interventions that can preserve muscle area, density, and function over time.

Desenvolvimento biomecânico e avaliação de uma nova estrutura para reabilitação all-on-four.

Introdução: Para a reabilitação completa de mandíbulas totalmente edêntulas, a opção de carga imediata determina o uso de próteses provisórias que imobilizam os implantes instalados. Embora as próteses provisórias com reforço proporcionem reabilitações com benefícios biomecânicos, a não adoção desta recomendação coexiste em diferentes estudos sobre restaurações imediatas.
 Objetivo: Este estudo avalia um tipo de prótese para restaurar mandíbulas pelo conceito all-on-four.
 Material e método: O comportamento mecânico das próteses com a estrutura modificada foi avaliado in vitro , sob um ensaio de flexão mecânica unilateral em cantilever. Dois grupos representativos foram incluídos no conceito all-on-four, com um grupo teste G1 (n = 10) contendo estruturas modificadas e um grupo controle G2 (n = 10) que incluiu próteses acrílicas completas. As amostras foram submetidas à termociclagem com 500 ciclos (5 ° ± 2 ° C por 30 se 55 ° ± 2 ° por 30 s) e ao ensaio de flexão mecânica no cantilever.
 Resultado: O teste de Mann-Whitney revelou diferença significativa entre G1 e G2 (p <0,001). Na avaliação descritiva, o G1 apresentou média de 830,50 N até a fratura inicial da resina, enquanto o grupo controle apresentou média de 403,58N. A resistência máxima até a fratura completa foi registrada no G1, com média de 903,03N, enquanto no G2, foi registrada uma média de 435,20N. O componente linear vertical da flexão foi de 0,68 mm e 0,39 mm até a fratura inicial da barra, respectivamente para G1 e G2.
 Conclusão: A estrutura modificada para o protocolo all-on-four determinou melhor desempenho mecânico quando comparado ao mesmo modelo de prótese acrílica completa.

Predictor index of functional limb length discrepancy.

Limb length discrepancy (LLD) of lower extremities is underdiagnosed due to compensatory mechanisms during locomotion. The natural course of compensation leads to biomechanical alteration in human musculoskeletal system leading to adverse effects. General consensus accepts LLD more than 2 cm as significant to cause biomechanical alteration. No studies were conducted correlating height and lower extremities true length (TL) to signify LLD. Examining significant LLD in relation to height and TL using dynamic gait analysis with primary focus on kinematics and secondary focus on kinetics would provide an objective evaluation method. Forty participants with no evidence of LLD were recruited. Height and TL were measured. Reflective markers were attached at specific points in lower extremity and subjects walked in gait lab at a self-selected normal walking pace with artificial LLDs of 0, 1, 2, 3, and 4 cm simulated using shoe raise. Accommodation period of 30 min was given. Infrared cameras were used to capture the motion. Primary kinematic (knee flexion and pelvic obliquity (PO)) and secondary kinetic (ground reaction force (GRF)) were measured at right heel strike and left heel strike. Functional adaptation was analyzed and the postulated predictor indices (PIs) were used as a screening tool using height, LLD, and TL to notify significance. There was a significant knee flexion component seen in height category of less than 170 cm. There was significant difference between LLD 3 cm and 4 cm. No significant changes were seen in PO and GRF. PIs of LLD/height and LLD/TL were analyzed using receiver operating characteristic curve. LLD/height as a PI with value of 1.75 was determined with specificity of 80% and sensitivity of 76%. A height of less than 170 cm has significant changes in relation to LLD. PI using LLD/height appears to be a promising tool to identify patients at risk.

Cervical Spinal Cord Injury Associated With Neck Flexion in Posterior Cervical Decompression

A retrospective analysis of prospectively collected data of 179 consecutive patients who underwent intraoperative neurophysiological monitoring during posterior cervical spine surgery for compression myelopathy. To evaluate preoperative factors in patients with deteriorating spinal cord function due to flexion of the neck during posterior cervical spine surgery by observing changes in waveforms on intraoperative monitoring. We encountered several cases of intraoperative monitoring warning alerts because of neck flexion during posterior cervical spine surgery. We investigated the incidence rate and intraoperative predictors of deteriorating spinal cord function caused by neck flexion based on waveform changes. Subjects were 179 patients who underwent posterior cervical decompression for spinal cord compression. When warning alarms were set off by amplitude changes in the period between skin incision and exposure of the lamina, the neck position was changed from flexion to neutral, and patients whose electrical potentials recovered following cervical repositioning were placed in the flexion-induced potential reduction group. We then analyzed and extracted risk factors for flexion-induced reduction in electrical potentials. In total, 156 patients were analyzed in this study. Monitoring alarms went off intraoperatively for 7 patients (4.5%) at the time of posterior cervical spine exposure. With regard to the most compressed level, the occupancy ratio of the anterior compression component, the kyphotic angle in flexion, and range of motion in the neutral position to flexion were significantly associated with flexion-induced reduction in electrical potentials. Furthermore, logistic regression analysis extracted the occupancy ratio of the anterior compression component at the most compressed level and the kyphotic angle of the most compressed level in flexion. Our findings suggest that a large anterior compression component and large kyphotic angle in neck flexion at the most compressed level are risk factors for intraoperative spinal cord injury during posterior cervical spine surgery.

Impact of intraoperative adjustment method for increased flexion gap on knee kinematics after posterior cruciate ligament-sacrificing total knee arthroplasty

BackgroundIn general, the flexion gap is larger than the extension gap with posterior cruciate ligament-sacrificing total knee arthroplasty. Several methods compensate for an excessive flexion gap, but their effects are unknown. The purpose of this study was to compare three methods to compensate for an increased flexion gap. MethodsIn this study, squatting in knees with excessive (4 mm) and moderate (2 mm) flexion gaps was simulated in a computer model. Differences in knee kinematics and kinetics with joint line elevation, setting the femoral component in flexion, and using a larger femoral component as compensatory methods were investigated. FindingsThe rotational kinematics during flexion with setting the femoral component in flexion were opposite to those in the other models. Using a larger femoral component resulted in the most physiological motion. The peak anterior translation was 10 mm in the joint line elevation model compared with approximately 6 mm in the other models. In the joint line elevation model, patellofemoral contact stress was excessively increased at 90° of knee flexion. In contrast, tibiofemoral contact stress was higher during knee extension with setting the femoral component in flexion due to anterior impingement. There were few differences in the effect of the three compensatory methods with a moderate flexion gap. InterpretationA larger femoral component should be used to compensate for an excessive flexion gap because it has less negative impact on posterior cruciate ligament-sacrificing total knee arthroplasty, whereas any compensation method might be acceptable for a moderate flexion gap.

Passive elastic contribution of hip extensors to joint moments during walking in people with low back pain

BackgroundIt has been found that alterations in passive muscle properties may be associated with low back pain, and these may be responsible for the altered gait parameters often observed in subjects with back pain. The purpose of the present study was to assess total hip and passive hip extensor moments in people with or without low back pain during the hip flexion component of walking. Methods52 subjects volunteered for this study (low back pain group, n = 25 (male n = 13, female n = 12), control group, n = 27 (male n = 15, female n = 12)). Passive hip moments were calculated using an adapted force transducer during supine testing. A biomechanical model and predictive equation were used to calculate passive hip moments during walking. Total hip moments were calculated with the use of a 9 camera, 3-D motion-capture system. FindingsIndependent samples t-tests demonstrated no significant differences between groups for gait parameters or hip or knee angles. Results of the ANOVAs demonstrated significant differences in passive hip flexor moments during the second half of hip flexion (P < 0.05).There were also significant differences in hip power and work done during peaks of power absorption and the second peak of power generation (P < 0.05). InterpretationThe present data demonstrates that subjects with low back pain have altered passive hip extensor and total power and work done during walking compared with healthy controls. Biomechanical models should include individual measurements of passive joint moments.

Congenital contracture of the iliotibial tract: a case report

Introduction. Congenital contracture of the iliotibial tract is a rather rare pathology that causes difficulties in diagnosing and planning treatment activities. The lack of a clear idea of the causes of the disease has led to disagreement in the interpretation of the diagnosis in patients with this pathology. In the Russian-language literature, this disease is referred to as idiopathic extension and abduction contracture of a hip joint or idiopathic contracture of the dorsal gluteal muscle (a congenital contracture of the tendons of the dorsal gluteal muscles), whereas the English-language literature more often highlights congenital or idiopathic contracture of the dorsal gluteal muscles.&#x0D; Clinical сase. The results of treatment of a 6-year-old child with congenital contracture of the iliotibial tract is presented. The child exhibited lameness when walking first started, but the correct diagnosis was not established. Clinically, along with the limitation of adduction and extension in the hip joint and an induration of the soft tissue along the external surface of the right thigh, the pelvis was skewed, and there was shortening of the right lower limb and a valgus deformity of diaphysis of the right femoral bone. Ultrasonographic and magnetic resonance imaging indicated the presence of a fibrous bridle over the outer surface of the right thigh. The fibrous bridle was excised for 15 cm, and a temporary hemiepiphysiodesis of the medial portion of the distal growth zone of the right femur was performed.&#x0D; Results and discussion. At the 1-year control examination, the patient did not present any complaints. There was no relapse of the contracture. According to X-ray study results, correction of the valgus deformity of the right femur was achieved, and the metal structures were removed. Despite the more frequent extension and abduction direction of the contracture of the iliotibial tract indicated by most authors, the direction and severity apparently may depend on the predominant zone of fibrous degeneration of the muscle groups. Additionally, with the predominant lesion of the dorsal gluteal muscle, a more pronounced extension component can be expected, whereas with the predominant lesion of the musculus tensor fasciae latae, a flexion component can be expected and was observed in our patient.

Elevated Lip Liner Positions Improving Stability in Total Hip Arthroplasty – An Experimental Study

Background: The use of elevated lip polyethylene liners with the acetabular component is relatively common in Total Hip Arthroplasty (THA). Elevated lip liners increase stability of the THA by increasing the jump distance in one direction. However, the elevated lip, conversely, also reduces the primary arc in the opposite direction and leads to early impingement of the neck on the elevated lip, potentially causing instability. The aim of the present study is to determine the total range of motion of the femoral head component within the acetabular component with the elevated lip liner in different orientations within the acetabular cup.Methods: We introduce a novel experimental (ex-vivo) framework for studying the effects lip liner orientation on the range of motion of the femoral component. For constant acetabular cup orientation, the elevated lip liner was positioned superiorly and inferiorly. The femoral component range of motion in the coronal, sagittal and axial plane was measured. To avoid any confounding influences of out of plane motion, the femoral component was constrained to move in the tested plane.Results: This experimental set up introduces a rigorous framework in which to test the effects of elevated lip liner orientations on the range of motion of the femoral head component in abduction, adduction, flexion, extension and rotation. The movements of this experimental set-up are directly informative of patient’s maximum potential post-operative range of motion. Initial results show that an inferior placement of the elevated lip increases the effective superior lateral range of motion (abduction) for the femoral component, whilst the anatomy of the patient (i.e. their other leg) prevents the point of femoral component – acetabular lip impingement being reached (in adduction).

Impingement of the patellar component against the tibial post after posterior stabilized and constrained TKA: a pilot study.

Patella-post impingement (PPI), contact of the patellar component with the tibial post, occurs during deep knee flexion after posterior stabilized total knee arthroplasty (TKA). PPI can cause anterior knee pain, increased patellar pressure, wear of the polyethylene patellar component and tibial post, and poor range of motion. There have been no reports on the relationship between PPI and tibial post design. The aim of this study was to compare different tibial post designs with regard to PPI incidence. Five posterior stabilized total knee prostheses were implanted in full-length models of the femur and tibia (Sawbones) using a navigation system. The thickness of the tibial component was 10mm in all prostheses. The patella was set on a transparent polypropylene sheet, which was fixed to the tibial tubercle. The distance between the lower edge of the patellar component and the cut surface of the tibia was defined as the tibial-patellar clearance (TPC), which represents the length of the patellar tendon. The TPC was varied from 18 to 40mm and the knee was moved from full extension to deep flexion while the knee angle at which PPI occurred (PPI angle) was recorded. The PPI angle differed between tibial post designs (p < 0.05). Shorter TPCs resulted in smaller PPI angles and longer TPCs resulted in larger PPI angles (p < 0.05). This is the first study to analyze the relationship between PPI and the design of tibial post. Our results clearly show that tibial post design and TPC affect PPI. To avoid patellar component and tibial post impingement in deep flexion, appropriate TPC must be achieved during surgery. Improvements in tibial post design, especially in constrained prostheses, are also desirable. This study highlights the potential risk of PPI during deep flexion after TKA.

Flexion Reflex Can Interrupt and Reset the Swimming Rhythm

The spinal cord can generate the hip flexor nerve activity underlying leg withdrawal (flexion reflex) and the rhythmic, alternating hip flexor and extensor activities underlying locomotion and scratching, even in the absence of brain inputs and movement-related sensory feedback. It has been hypothesized that a common set of spinal interneurons mediates flexion reflex and the flexion components of locomotion and scratching. Leg cutaneous stimuli that evoke flexion reflex can alter the timing of (i.e., reset) cat walking and turtle scratching rhythms; in addition, reflex responses to leg cutaneous stimuli can be modified during cat and human walking and turtle scratching. Both of these effects depend on the phase (flexion or extension) of the rhythm in which the stimuli occur. However, similar interactions between leg flexion reflex and swimming have not been reported. We show here that a tap to the foot interrupted and reset the rhythm of forward swimming in spinal, immobilized turtles if the tap occurred during the swim hip extensor phase. In addition, the hip flexor nerve response to an electrical foot stimulus was reduced or eliminated during the swim hip extensor phase. These two phase-dependent effects of flexion reflex on the swim rhythm and vice versa together demonstrate that the flexion reflex spinal circuit shares key components with or has strong interactions with the swimming spinal network, as has been shown previously for cat walking and turtle scratching. Therefore, leg flexion reflex circuits likely share key spinal interneurons with locomotion and scratching networks across limbed vertebrates generally. The spinal cord can generate leg withdrawal (flexion reflex), locomotion, and scratching in limbed vertebrates. It has been hypothesized that there is a common set of spinal cord neurons that produce hip flexion during flexion reflex, locomotion, and scratching based on evidence from studies of cat and human walking and turtle scratching. We show here that flexion reflex and swimming also share key spinal cord components based on evidence from turtles. Foot stimulation can reset the timing of the swimming rhythm and the response to each foot stimulation can itself be altered by the swim rhythm. Collectively, these studies suggest that spinal cord neuronal networks underlying flexion reflex, multiple forms of locomotion, and scratching share key components.

Meniscal Bearing Dislocation of Unicompartmental Knee Arthroplasty with Faint Symptom.

We experienced two cases of atypical lateral dislocations of meniscal bearing in UKA (unicompartmental knee arthroplasty) without manifest symptoms. The dislocated bearing, which jumped onto the wall of tibial components, was found on radiographs in periodic medical examination although they could walk. Two thicker size bearing exchanges were promptly performed before metallosis and loosening of components. Continual examination is important to mobile bearing type of UKA because slight or less symptoms may disclose such unique dislocation. One case showed malrotation of the femoral component on 3D image. Anteroposterior view hardly disclosed the malrotation of the femoral component. Epicondylar view is an indispensable view of importance, and it can demonstrate the rotation of the femoral component. The the femoral distal end is wedge shaped and is wider posteriorly. If the femoral component is set according to the shape of medial condyle, the femoral component shifts to medial site compared with tibial component in flexion. It can account for such rare dislocation as follows. If excessive force applies on most medial side of the bearing during flexion, the lateral part of the bearing pops and the force squeezes it laterally simultaneously. Finally, the bearing jumps onto the lateral wall of the tibial component.

A Novel Method for Intraoperative Reduction of the Mobile Meniscal Bearing in the Oxford Unicompartmental Knee Replacement

Insertion of the bearing can be challenging due to patient body habitus or limited exposure when using a minimally invasive technique. We describe a novel way of inserting the bearing not previously described in the literature. The bearing is positioned on the femoral component in full flexion. Then, with a gentle extension of the knee, the bearing snaps into position and is seated correctly on a consistent basis.

ED plaster-of-Paris jacket for infantile scoliosis.

There are various articles published in last few years which consider surgical methods like growing rod instrumentation and modulation of the growth as a "gold standard" for the treatment of early onset severe scoliosis. We emphasize orthopaedic correction with serial casting as another option for such progressive deformity. The key to the success of this treatment is to understand the strategy and the technique involved in the effective casting. The conventional technique of elongation, derotation, flexion cast (named EDF by Cotrel) is described with some modifications like wedging the cast (gypsotomy) in order to produce the flexion component. Serial casting with ED casts for the treatment of progressive idiopathic infantile scoliosis is an effective tool for the benign types of curves (Mehta) and spinal fusion was not necessary in two-third of our cases. Surgical option for treatment of early onset scoliosis is not a "gold standard". Orthopaedic treatment with serial elongation, derotation casts remain the centerpiece of this treatment. Each detail to understand the technique must be known in order to obtain the best result.

Increased risk of revision for high flexion total knee replacement with thicker tibial liners

The outcome of total knee replacement (TKR) using components designed to increase the range of flexion is not fully understood. The short- to mid-term risk of aseptic revision in high flexion TKR was evaluated. The endpoint of the study was aseptic revision and the following variables were investigated: implant design (high flexion vs non-high flexion), the thickness of the tibial insert (≤ 14 mm vs > 14 mm), cruciate ligament (posterior stabilised (PS) vs cruciate retaining), mobility (fixed vs rotating), and the manufacturer (Zimmer, Smith & Nephew and DePuy). Covariates included patient, implant, surgeon and hospital factors. Marginal Cox proportional hazard models were used. In a cohort of 64 000 TKRs, high flexion components were used in 8035 (12.5%). The high flexion knees with tibial liners of thickness > 14 mm had a density of revision of 1.45/100 years of observation, compared with 0.37/100 in non-high flexion TKR with liners ≤ 14 mm thick. Relative to a standard fixed PS TKR, the NexGen (Zimmer, Warsaw, Indiana) Gender Specific Female high flexion fixed PS TKR had an increased risk of revision (hazard ratio (HR) 2.27 (95% confidence interval (CI) 1.48 to 3.50)), an effect that was magnified when a thicker tibial insert was used (HR 8.10 (95% CI 4.41 to 14.89)). Surgeons should be cautious when choosing high flexion TKRs, particularly when thicker tibial liners might be required.

Clinical tests for differentiating between patients with and without patellofemoral pain syndrome

Abstract Patellofemoral pain syndrome (PFPS) is a very common knee condition with various aetiologies. Because of the nebulous factors of the syndrome, physiotherapists often find it difficult to assess and treat these patients. The aim of this study was to identify the clinical assessment tool that can differentiate PFPS patients from patients with other lower limb conditions. Fifty-two patients from the National Health System (26 with PFPS and 26 with other lower limb conditions) took part in this study. They underwent a series of strength, flexibility, and stress tests. Their pain levels were also recorded. The results showed that among the various clinical tests, only the hip flexion component of the Thomas test was able to differentiate between the two groups. In addition, the stress test showed that the PFPS group could not recover their gluteal muscle strength in the same way the group with the other lower limb conditions did. The Lower Extremity Functional Scale was found to be more able to differentiate between the two groups than the Anterior Knee Pain Scale. This study has shown that it is difficult to find specific clinical tests to diagnose PFPS. More research is needed in this important area.

MANAGEMENT OF FLEXOR TENDON INJURIES — PART 2: CURRENT PRACTICE IN AUSTRALIA AND GUIDELINES FOR TRAINING YOUNG SURGEONS

This study aims to gain a better understanding of current practice for the surgical management and rehabilitation of flexor tendon injuries in Australia, with the intent of establishing common guidelines for training of young surgeons. A survey was distributed to the membership of the Australian Hand Surgery Society to determine whether a consensus could be obtained for: suture material and gauge; core and epitenon suture techniques; sheath and pulley management; and post-operative protocols for primary flexor tendon repair. The predominant materials used for core suture are Ticron™ Suture (Tyco Healthcare Group LP, Norwalk, Connecticut, USA) (34%) and Ethibond™ Polyester Suture (Ethicon, Somerville, New Jersey, USA) (24%). The two core suture configurations commonly used are the Adelaide (45%) and Kessler (32%) repair. The predominant materials used for epitendinous sutures are 6-0 Prolene™ Polypropylene Suture (Ethicon, Somerville, New Jersey, USA) (56%), 5-0 Prolene™ (21%) and 6-0 Ethilon™ Nylon Suture (Ethicon, Somerville, New Jersey, USA) (13%); and the majority (63%) use a running epitendinous technique. The management of critical pulleys is variable, with 89% prepared to perform some release of A2 and A4 pulleys. Rehabilitation protocols vary widely, with 24% of respondents using the same method for all patients, while 76% tailor their approach to each patient. Some component of active motion was used by most. There exists some consensus on the management of flexor tendon injuries in Australia. However, the management of critical pulleys and methods of post-operative rehabilitation remain varied. For the training of young surgeons, a majority advise a 3-0 gauge braided polyester core suture of four strands, combined with a 6-0 Prolene™ simple running epitendinous suture for increased tendon repair strength and smooth glide. Trainees should attempt to retain the integrity of the A2 and A4 pulleys. Post-operative rehabilitation should include a component of active flexion.

Femoral and tibial component rotation in total knee arthroplasty

At least four ways have been described to determine femoral component rotation, and three ways to determine tibial component rotation in total knee replacement (TKR). Each method has its advocates and each has an influence on knee kinematics and the ultimate short and long term success of TKR. Of the four femoral component methods, the author prefers rotating the femoral component in flexion to that amount that establishes a stable symmetrical flexion gap. This judgement is made after the soft tissues of the knee have been balanced in extension. Of the three tibial component methods, the author prefers rotating the tibial component into congruency with the established femoral component rotation with the knee is in extension. This yields a rotationally congruent articulation during weight-bearing and should minimise the torsional forces being transferred through a conforming tibial insert, which could lead to wear to the underside of the tibial polyethylene. Rotating platform components will compensate for any mal-rotation, but can still lead to pain if excessive tibial insert rotation causes soft-tissue impingement.

Pause time alters the preparation of two-component movements

Targeted reciprocal aiming movements are pervasive in everyday life, but it is unclear how the timing parameters between task elements affect the preparation of these movements. This study used a loud (124 dB) startling acoustic stimulus (SAS) to probe how changes in the pause time between the outward and return components of a reciprocal aiming task affected the preparatory state of the motor system. Participants performed a visually guided wrist extension-flexion task to a target located at 20° from the start position and were instructed to pause the movement within the wrist extension target zone for either 50, 200, or 500 ms. A SAS was presented during 25 % of trials before either the onset of the wrist extension (out) or flexion (return) components of the task to determine how motor preparation was affected by task requirements. Results showed that the presentation of a SAS prior to the initial outward movement led to significantly earlier onsets of both the outward and return components (p < .05), indicating that the pause time in the planned action was pre-planned. For the longer (200, 500 ms) pause-time conditions, a SAS delivered prior to returning from the target region triggered the return portion of the movement early. These findings suggest that the shortest pause-time movement (50 ms) was preplanned as a single action, whereas for reciprocal movements with longer pause times at least the initial part of the movement and the timing of the pause were preplanned and integrated, while the return portion was more independent.