The authors would like to thank Joao Tomas for his technical assistance with the device and Khaoula Louati for assistance in developing the image analysis methods.

The rat knee immobilization model used has been approved by the University of Ottawa Animal Care and Veterinary Service and the local ethics committee.
1. Animal Preparation
<ol>
	<li>At the end of the predetermined immobilization period, euthanize the rats by administration of carbon dioxide. 
	NOTE: Here we used an immobilization model with a plate and 2 screws (one inserted in the proximal femur and the other in the distal tibia), which avoids violation of any knee joint stru...

<ol>
	<li>Clavet, H., H&#233;bert, P. C., Fergusson, D., Doucette, S., Trudel, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Joint+contracture+following+prolonged+stay+in+the+intensive+care+unit.">Joint contracture following prolonged stay in the intensive care unit.</a> Canadian Medical Association Journal. 178 (6), 691-697 (2008).</li><li>Campbell, T. M., Dudek, N., Trudel, G., Silver, J. K., Frontera, W. R., Rizzo, T. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Essentials of Physical Medicine and Rehabilitation: musculoskeletal disorders, pain, and rehabilitation. , (2015).</li><li>Dehail, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acquired+deforming+hypertonia+and+contractures+in+elderly+subjects:+definition+and+prevalence+in+geriatric+institutions+(ADH+survey).">Acquired deforming hypertonia and contractures in elderly subjects: definition and prevalence in geriatric institutions (ADH survey).</a> Annals of Physical and Rehabilitation Medicine. 57 (3), 11-23 (2014).</li><li>Korp, K., Richard, R., Hawkins, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Refining+the+idiom+&amp;#34;functional+range+of+motion&amp;#34;+related+to+burn+recovery.">Refining the idiom &amp;#34;functional range of motion&amp;#34; related to burn recovery.</a> Journal of Burn Care and Research. 36 (3), 136-145 (2015).</li><li>Elliott, L., Walker, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rehabilitation+interventions+for+vegetative+and+minimally+conscious+patients.">Rehabilitation interventions for vegetative and minimally conscious patients.</a> Neuropsychological Rehabilitation. 15 (3-4), 480-493 (2005).</li><li>Campbell, T. M., Reilly, K., Laneuville, O., Uhthoff, H., Trudel, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bone+replaces+articular+cartilage+in+the+rat+knee+joint+after+prolonged+immobilization.">Bone replaces articular cartilage in the rat knee joint after prolonged immobilization.</a> Bone. 106, 42-51 (2017).</li><li>Trudel, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+alterations+of+rabbit+Achilles'+tendon+after+immobilization+correlate+with+bone+mineral+density+but+not+with+magnetic+resonance+or+ultrasound+imaging.">Mechanical alterations of rabbit Achilles' tendon after immobilization correlate with bone mineral density but not with magnetic resonance or ultrasound imaging.</a> Archives of Physical Medicine and Rehabilitation. 88 (12), 1720-1726 (2007).</li><li>Harvey, L. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stretch+for+the+treatment+and+prevention+of+contractures.">Stretch for the treatment and prevention of contractures.</a> Cochrane Database of Systematic Reviews. 1, Cd007455 (2017).</li><li>Trudel, G., Himori, K., Uhthoff, H. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contrasting+alterations+of+apposed+and+unapposed+articular+cartilage+during+joint+contracture+formation.">Contrasting alterations of apposed and unapposed articular cartilage during joint contracture formation.</a> Archives of Physical Medicine Rehabilitation. 86 (1), 90-97 (2005).</li><li>Trudel, G., Uhthoff, H. K., Goudreau, L., Laneuville, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+analysis+of+the+reversibility+of+knee+flexion+contractures+with+time:+an+experimental+study+using+the+rat+model.">Quantitative analysis of the reversibility of knee flexion contractures with time: an experimental study using the rat model.</a> BMC Musculoskeletal Disorders. 15, 338 (2014).</li><li>Trudel, G., Uhthoff, H. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contractures+secondary+to+immobility:+is+the+restriction+articular+or+muscular?+An+experimental+longitudinal+study+in+the+rat+knee.">Contractures secondary to immobility: is the restriction articular or muscular? An experimental longitudinal study in the rat knee.</a> Archives of Physical Medicine and Rehabilitation. 81 (1), 6-13 (2000).</li><li>Chimoto, E., Hagiwara, Y., Ando, A., Itoi, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progression+of+an+arthrogenic+motion+restriction+after+immobilization+in+a+rat+experimental+knee+model.">Progression of an arthrogenic motion restriction after immobilization in a rat experimental knee model.</a> Upsala Journal of Medical Sciences. 112 (3), 347-355 (2007).</li><li>Ando, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Remobilization+does+not+restore+immobilization-induced+adhesion+of+capsule+and+restricted+joint+motion+in+rat+knee+joints.">Remobilization does not restore immobilization-induced adhesion of capsule and restricted joint motion in rat knee joints.</a> Tohoku Journal of Experimental Medicine. 227 (1), 13-22 (2012).</li><li>Abdel, M. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+joint+contracture+on+the+contralateral+unoperated+limb+in+a+rabbit+knee+contracture+model:+a+biomechanical+and+genetic+study.">Effects of joint contracture on the contralateral unoperated limb in a rabbit knee contracture model: a biomechanical and genetic study.</a> Journal of Orthopaedic Research. 30 (10), 1581-1585 (2012).</li><li>Hildebrand, K. A., Sutherland, C., Zhang, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rabbit+knee+model+of+post-traumatic+joint+contractures:+the+long-term+natural+history+of+motion+loss+and+myofibroblasts.">Rabbit knee model of post-traumatic joint contractures: the long-term natural history of motion loss and myofibroblasts.</a> Journal of Orthopaedic Research . 22 (2), 313-320 (2004).</li><li>Klein, L., Player, J. S., Heiple, K. G., Bahniuk, E., Goldberg, V. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isotopic+evidence+for+resorption+of+soft+tissues+and+bone+in+immobilized+dogs.">Isotopic evidence for resorption of soft tissues and bone in immobilized dogs.</a> Journal of Bone and Joint Surgery. American Volume. 64 (2), 225-230 (1982).</li></ol>

The rat knee arthrometer was developed to reproducibly and reliably determine the maximum extension of the rat knee following an intervention. Advantages of this device include the consistent generation of torque across the knee joint with a constant arm length and extension force. Another advantage includes the ability to set the torque at a level that allows repetitive testing on the same joint to evaluate the influence of different articular structures on knee ROM, such as muscle, capsule, or ligament. For example, fo...

Having full range of motion (ROM) of the joints is critical for health and well-being1. A loss in joint passive ROM is called a contracture2. Joint contractures may arise from numerous conditions, including prolonged bedrest, paralysis, joint arthroplasty, burns, infection, and neurologic conditions1,3,4,5. A contracture of the knee can be disabling as it accelerates joint degeneration, increases the risk of falls and detrimentally affects a person&#39;s ability to perform basic functional tasks including walking, sitting, and climbing stairs6,7.
Once established, contractures of the knee are difficult to treat, and therefore determining which patients are at the highest risk of developing this condition is essential for prevention and avoidance of contracture-associated morbidity8. Experiments are designed to evaluate 1) the conditions causing or influencing knee joint contractures, 2) the severity of contractures, 3) their temporal progression, 4) the tissues involved in the contracture, 5) their reversibility as well as 6) the usefulness of various preventive and curative interventions on knee joint ROM. For all of these experiments, a valid, objective, precise and reproducible method for measuring the ROM is critical. Other ancillary measures (energy expenditure, histomorphometry, gene expression and protein content) are useful markers to understand the pathophysiology of joint contractures, but the mechanical limitation is what limits the patient and leads to disability. Some of the challenges in this area of research includes the heterogeneous methods by which knee ROM may be tested experimentally, as well as a lack of quantitative data9. The use of a variety of different experimental methods leads to results that are not comparable from laboratory to laboratory. This has led to controversy regarding the conditions (such as immobilization or joint arthroplasty) that cause joint contractures10. An automated method of experimentally measuring joint ROM following an intervention is therefore needed.
Here, we describe a user-independent, valid, precise and reproducible protocol for evaluating the rat knee ROM using a custom-built arthrometer linked to a digital camera to precisely measure the knee ROM in extension. We tested the effect of various periods of immobilization on knee ROM. We then describe the methods for measuring ROM at pre-specified torques on the resulting digital images using fixed bony landmarks. Overall, these methods reliably measure rat knee ROM and provide quantitative data.

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			<td height="64" style="height:64px;width:251px;">Arthrometer</td>
			<td style="width:205px;">The Ottawa Hospital Rehabilitation Centre - Rehabilitation Engineering&#160;</td>
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			<td height="22" style="height:22px;width:251px;">ImageJ</td>
			<td style="width:205px;">National Institutes of Health</td>
			<td style="width:119px;">Version 1.45s</td>
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using a knee arthrometer to evaluate tissue-specific contributions to knee flexion contracture in the rat

Normal knee range of motion (ROM) is critical to well-being and allows one to perform basic activities such as walking, climbing stairs and sitting. Lost ROM is called a joint contracture and results in increased morbidity. Due to the difficulty of reversing established knee contractures, early detection is important, and hence, knowing risk factors for their development is essential. The rat represents a good model with which the effect of an intervention can be studied due to the similarity of rat knee anatomy to that of humans, the rat's ability to tolerate long durations of knee immobilization in flexion, and because mechanical data can be correlated with histologic and biochemical analysis of knee tissue.
Using an automated arthrometer, we demonstrate a validated, precise, reproducible, user-independent method of measuring the extension ROM of the rat knee joint at specific torques. This arthrometer can be used to determine the effects of interventions on knee joint ROM in the rat.

The amount of knee extension determined for various periods of immobility are summarized for increasing durations of immobility and show that more severe contractures were produced following increasing lengths of immobilization. Representative results using ImageJ are shown in Figure 3.
The ability to measure maximum extension of rat knees in a valid, precise and reproducible, user-independent manne...

Watch this Scientific Journal Video about Using a Knee Arthrometer to Evaluate Tissue-specific Contributions to Knee Flexion Contracture in the Rat at JoVE.com

Using a Knee Arthrometer to Evaluate Tissue-specific Contributions to Knee Flexion Contracture in the Rat

The goal of the protocol is to measure the extension range of motion of the rat knee. The effects of various diseases that increase the stiffness of the knee joint and the effectiveness of treatments can be quantified.

Normal knee range of motion (ROM) is critical to well-being and allows one to perform basic activities such as walking, climbing stairs and sitting. Lost ...

This method can help answer key questions in the musculoskeletal field, such as the effect of an intervention on knee joint range of motion using a rat model. The main advantage of this technique is that it provides a precise, reproducible, user independent method for measuring rat knee joint extension. Start by using scissors and forceps to deglove the lower extremity of the euthanized rat and remove skin from underlying facia.Then, position the body on its side with the experimental leg facing upwards. Place the femur in the grooved metal clamp that is integrated into the mounting stage of the arthrometer. Secure the femur by punching holes through through muscle with the precision screwdriver to place the clamp distal to the greater trochanter.Then, adjust the lateral femoral condyle over the center of rotation of the arthrometer. Position the movable arm with two upright posts behind the leg, just proximal to the calcaneus to push the knee into passive extension once the electric motor is activated. Use a hex key to tighten the femur clamp at its base until it is secured.Ensure that the camera is correctly mounted on the arthometer using a screwdriver. Check that the camera is on manual focus, and focus the camera on the femora condyle. Set the direction of the arthrometer clockwise or counterclockwise depending on the direction of the knee range of movement being tested and the position of the rat.Activate the arthrometer motor by simultaneously pushing the power and start buttons. The arthrometer motor will move at a speed of 6.6 rpm and then stop for 2.1 seconds upon reaching the first preset torque. When the first torque is reached, the corresponding LED will light up and the digital camera will take a picture of the knee automatically.Once the picture is taken, the arthrometer will continue to the next higher preset torque. Once the four torques have been applied, the arthrometer will stop. Once the rat is positioned on the arthrometer and testing is initiated, the total time for testing one knee is approximately 18.8 seconds.To isolate the arthrogenic or non-muscular component of a contracture, reset the torque sequence to release the force applied to the leg, then perform a myotomy the posterior transarticular muscles. Dissect the muscle proximal enough to the knee joint to ensure that the capsule is not cut. After testing both legs before and after myotomy, and dissecting out any required tissues, dispose of the animal carcass and all biohazardous materials following institutional protocol and clean the arthrometer.Open the file containing the digital image taken by the camera mounted on the arthrometer in Image J.The person performing the analysis should be blinded to the experimental grouping of the animal. Select the angle tool from the main toolbar and trace the femoral-tibial angle by drawing a femoral line from the middle of the femur clamp to the lateral condyle, and the tibial line from the lateral femoral condyle to the lateral malleolus. Use the measuring tool by clicking Analyze then Measure to show the calculated angle produced by the two lines drawn above.Use the convention of zero degrees to mean full extension. This figure shows maximum knee extension following 16 weeks of immobilization for seven rats compared to the non-immobilized contralateral limb. For the immobilized knee, the ability for maximum extension was reduced compared to the contralateral.Following myotomy, the maximal extension capability for the experimental and contralateral knee increased, however, the experimental knee continue to demonstrate a flexion contracture. While attempting this procedure, it's important to ensure that the femoral clamp is well-secured in order to avoid movement of the knee during testing. Following this procedure, other methods like histologic analysis of the knee, articular structure can be performed to answer additional questions pertaining to the tissue and cellular changes that occur in the knee joint to affect its range in motion.

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6.6K visualizações.  Elizabeth Bruyère Hospital. Este método pode ajudar a responder a perguntas-chave no campo musculoesquelético, como o efeito de uma intervenção na faixa articular do joelho usando um modelo de rato. A principal vantagem desta técnica é que ela fornece um método preciso, reprodutível e independente do usuário para medir a extensão articular do joelho de rato. Comece usando tesouras e fórceps para deglove a extremidade inferior do rato eutanizado e remova a pele da fácia subjacente.Em seguida, posicione...