Comparison of interobserver agreement between the evaluation of bicipital and the patellar tendon reflex in healthy dogs.
ABSTRACT: The reliability of reflex-assessment is currently debatable, with current literature regarding the patellar tendon reflex (PTR) as highly reliable, while the biceps tendon reflex (BTR) is regarded to be of low reliability in the dog. Such statements are, however, based on subjective observations rather than on an empirical study. The goals of this study were three-fold: (1) the quantification of the interobserver agreement (IA) on the evaluation of the canine bicipital (BTR) and patellar tendon (PTR) reflex in healthy dogs, (2) to compare the IA of the BTR and PTR evaluation and (3) the identification of intrinsic (sex, age, fur length, weight) and extrinsic (observer´s expertise, body side) risk factors on the IA of both reflexes. The observers were subdivided into three groups based on their expected level of expertise (neurologists = highest -, practitioners = middle-and veterinary students = lowest level of expertise). For the BTR, 54 thoracic limbs were analyzed and compared to the evaluation of the PTR on 64 pelvic limbs. Each observer had to evaluate the reflex presence (RP) (present or absent) and the reflex activity (RA) using a 5-point ordinal scale. Multiple reliability coefficients were calculated. The influence of the risk factors has been calculated using a mixed regression-model. The Odds Ratio for each factor was presented. The higher the level of expertise the higher was the IA of the BTR. For RP(BTR), IA was highest for neurologists and for RA(BTR) the IA was lowest for students. The level of expertise had a significant impact on the degree of the IA in the evaluation of the bicipital tendon reflex: for the RA(BTR), practitioners had a 3.4-times (p = 0.003) and students a 7.0-times (p < 0.001) higher chance of discordance. In longhaired dogs the chance of disagreement was 2.6-times higher compared to shorthaired dogs in the evaluation of RA(BTR) (p = 0.003). Likewise, the IA of the RP(PTR) was the higher the higher the observers´ expertise was with neurologists having significantly highest values (p < 0.001). The RA(PTR) has been evaluated more consistent by practitioners and students than the RA(BTR). For practitioners this difference was significant (< 0.01). Our data suggests that neurologists assess the bicipital and patellar tendon reflex in dogs most reliably. None of the examined risk factors had a significant impact on the degree of IA in the evaluation of RP(PTR), while students had a 4.4-times higher chance of discordance when evaluating the RA(PTR) compared to the other groups. This effect was significant (p < 0.001). Neurologists can reliably assess the bicipital and patellar tendon reflex in healthy dogs. Observer´s level of expertise and the fur length of the dog affect the degree of IA of RA(BTR). The influence of the observer´s expertise is higher on the evaluation of the BTR than on the PTR.
Project description:Objectives:To report the clinical and electrophysiological findings in two patients with multifocal motor neuropathy (MMN) and bilateral absent patellar and Achilles tendon reflexes despite normal strength of quadriceps and calf muscles. Methods:The medical history and clinical evaluation were completed by electrophysiological tests: sensory and motor nerve conduction studies, needle electromyography, motor-evoked potentials (MEPs) after transcranial magnetic stimulation, patellar T (tendon) responses, quadriceps and soleus H (Hoffman) reflex recordings. Results:In the two patients, history, clinical evaluation, nerve conduction studies, favorable response to intravenous immunoglobulins, and positive anti-GM1 antibodies fulfilled the diagnosis of MMN. The lower limbs were asymptomatic, except for a unilateral weakness of foot dorsiflexion. The patellar and Achilles tendon reflexes disappeared during the course of the disease. The sensory nerve conduction studies were normal or minimally modified, M-wave and MEP/M amplitude ratio to the quadriceps were normal, patellar T (tendon) responses were virtually absent, and H-reflex to the quadriceps and soleus muscles were absent. Conclusions:These observations, which show the interruption of the reflex afferent pathway, raise the question of Ia afferent involvement in the lower limbs of these two patients with MMN. Further investigations should determine the frequency and significance of these findings in this disorder.
Project description:Tenodesis of the long head of the biceps tendon (LHB) at the upper part of the bicipital groove has been related to persistent postoperative bicipital pain. This is possibly due to the inflammation of the remaining tendon within the groove. This, in turn, could be attributed to the continual mechanical stress placed on the tendon in the narrow bicipital groove. Theoretically, should the LHB be more "relaxed," the mechanical stress applied on it would be diminished. On the basis of this rationale, we present an arthroscopic biceps tenodesis technique, according to which the tendon is fixed at the entrance of the bicipital groove, using a bioabsorbable screw, relaxed by 5 mm. In this lax position, the residual LHB tension is expected to be decreased compared with the initial tension, whereas no cosmetic deformity (Popeye sign) or impaired muscular performance is anticipated.
Project description:During the spring of 2016 at the University of Wisconsin-Milwaukee, we implemented a novel educational technology designed to teach undergraduates about the nervous system while allowing them to physically construct their own neural circuits. Modular, electronic neuron simulators called NeuroBytes were used by the students in BIOSCI202 Anatomy and Physiology I, a four-credit course consisting of three hours per week each of lecture and laboratory time. 162 students participated in the laboratory sessions that covered reflexes; 83 in the experimental sections used the NeuroBytes to build a model of the patellar tendon reflex, while 79 in the control sections participated in alternate reflex curricula. To address the question of whether or not the NeuroBytes-based patellar tendon reflex simulation brought about learning gains, the control and experimental group students underwent pre/post testing before and after their laboratory sections. We found that for several of the neuroscience and physiology concepts assessed on the test, the experimental group students had significantly greater declarative learning gains between the pre- and post-test as compared to the control group students. While there are numerous virtual neuroscience education tools available to undergraduate educators, there are relatively few designed to engage students in the basics of electrophysiology and neural circuitry using physical manipulatives, and none to our knowledge that allow them to build circuits from functioning hand-held "neurons."
Project description:The purpose of this study was to understand how stretch-related sensory feedback from an antagonist muscle affects agonist muscle output at different contraction levels in healthy adults. Ten young (25.3 ± 2.4 years), healthy subjects performed constant isometric knee flexion contractions (agonist) at 6 torque levels: 5%, 10%, 15%, 20%, 30%, and 40% of their maximal voluntary contraction. For half of the trials, subjects received patellar tendon taps (antagonist sensory feedback) during the contraction. We compared error in targeted knee flexion torque and hamstring muscle activity, with and without patellar tendon tapping, across the 6 torque levels. At lower torque levels (5%, 10%, and 15%), subjects produced greater knee torque error following tendon tapping compared with the same torque levels without tendon tapping. In contrast, we did not find any difference in torque output at higher target levels (20%, 30%, and 40%) between trials with and without tendon tapping. We also observed a load-dependent increase in the magnitude of agonist muscle activity after tendon taps, with no associated load-dependent increase in agonist and antagonist co-activation, or reflex inhibition from the antagonist tapping. The findings suggest that at relatively low muscle activity there is a deficiency in the ability to correct motor output after sensory disturbances, and cortical centers (versus sub-cortical) are likely involved.
Project description:There are many methods for long head of the biceps tendon (LHBT) tenodesis, but a consensus on a superior method has yet to be met. In this article, we introduce a method for arthroscopic suprapectoral biceps tenodesis using a tenodesis screw in the bicipital tunnel. The intra-articular portion of the biceps tendon is transected. The subdeltoid space is then viewed via a lateral portal, and the tendon is mobilized from the bicipital tunnel. The tendon is retrieved through the anterior portal, and 5 whipstitch passes and a second distal stitch are placed. Three of the suture tails are passed through the tenodesis screwdriver, and the tendon is maneuvered to the previously reamed bone socket located 1.5 cm superior to the pec tendon, just inferior to the bicipital groove. Once the tenodesis screw is fixated in sufficient bone stock, 5 alternating half hitches reinforce the construct by creating a closed loop through the screw. This described technique allows full visualization of the LHBT dissection and tenodesis throughout the procedure. Additionally, this technique provides a method to incorporate whipstitching with an arthroscopic tenodesis screw to provide additional strength to tendon fixation.
Project description:Biceps tenodesis is a common treatment for pathology of the long head of the biceps tendon. Several authors have described various arthroscopic and open techniques for biceps tenodesis. Open techniques have been associated with complications such as wound infection and nerve injury. Previously described arthroscopic techniques have placed the tenodesis site within the bicipital groove, which may lead to persistent pain. We describe an all-arthroscopic suprapectoral biceps tenodesis technique that places the tenodesis site distal to the bicipital groove. This technique potentially avoids the complications associated with open tenodesis surgery while still removing the biceps tendon from the bicipital groove.
Project description:Neurologic complications following acute respiratory distress syndrome (ARDS) are well described, however, information on the neurologic outcome regarding peripheral nervous system complications in critically ill ARDS patients, especially those who received extracorporeal membrane oxygenation (ECMO) are lacking. In this prospective observational study 28 ARDS patients who survived after ECMO or conventional nonECMO treatment were examined for neurological findings. Nine patients had findings related to cranial nerve innervation, which differed between ECMO and nonECMO patients (p = 0.031). ECMO patients had severely increased patella tendon reflex (PTR) reflex levels (p = 0.027 vs. p = 0.125) as well as gastrocnemius tendon reflex (GTR) (p = 0.041 right, p = 0.149 left) were affected on the right, but not on the left side presumably associated with ECMO cannulation. Paresis (14.3% of patients) was only found in the ECMO group (p = 0.067). Paresthesia was frequent (nonECMO 53.8%, ECMO 62.5%; p = 0.064), in nonECMO most frequently due to initial trauma and polyneuropathy, in the ECMO group mainly due to impairments of N. cutaneus femoris lateralis (4 vs. 0; p = 0.031). Besides well-known central neurologic complications, more subtle complications were detected by thorough clinical examination. These findings are sufficient to hamper activities of daily living and impair quality of life and psychological health and are presumably directly related to ECMO therapy.
Project description:Proximal biceps tendon pathology is a common source of shoulder symptoms. Thus, visualization of the entire extent of the biceps tendon is often required for both diagnostic and therapeutic purposes. Accurately recognizing the presence and extent of biceps pathology intraoperatively is made more difficult, however, due to the extra-articular location of a significant portion of the biceps tendon as it courses within the bicipital groove. Unfortunately, identification of the biceps groove in the subacromial space is often challenging due to the lack of visual and tactile landmarks. A technique that facilitates efficient and reliable bicipital groove identification and biceps tendon visualization along its entire course within the groove is presented.
Project description:OBJECTIVE:To quantify changes in the patellar tendon length following surgical correction of medial patellar luxation in dogs and evaluate potential risk factors associated with patellar tendon elongation. STUDY DESIGN:Retrospective case series (n = 50). METHODS:Dogs that underwent surgery for medial patellar luxation correction and had 2-3 months follow up were included. Digital radiographs were utilized to quantify the patellar tendon length to patellar length ratio at various follow-up points. Odds ratio comparisons between potential risk factors associated with changes in patellar tendon length were performed. RESULTS:Post-operative patellar tendon lengthening of ? 5% was observed in 20% of stifles and post-operative patellar tendon shortening of ? 5% was observed in 22% of stifles at the 2-3 month follow up period. The risk factors including age, body weight, trochleoplasty and grade of medial patellar luxation were not significantly associated with risk of patellar tendon elongation. Patellar tendon lengthening was not associated with recurrence of luxation. CONCLUSION:Patellar tendon lengthening and shortening can be observed in dogs following common medial patellar luxation corrective procedures in the short term follow up period. Patellar tendon lengthening does not appear to be associated with age, weight, trochleoplasty, grade of luxation, or risk of luxation recurrence.
Project description:The long head of the biceps tendon is frequently involved in shoulder pathologies, often in relation to inflammatory or degenerative damage to the rotator cuff. Biceps tenodesis in the bicipital groove and tenotomy are the main treatment options. Tenotomy of the long head of the biceps tendon is a simpler and quicker procedure than tenodesis, and it does not require the use of implants. However, retraction of the biceps tendon, leading to Popeye deformity, and biceps muscle cramps are common complications after tenotomy. Therefore we propose an arthroscopic technique for tenotomy that limits the risk of Popeye deformity. This procedure consists of creating a loop at the severed end of the biceps tendon, which prevents the tendon from retracting into the bicipital groove.