By: Amy Rosenthal, My Pet’s Brace Practitioner
You are helping a client fit a knee brace on their dog for the first time. You or your client may be asking: Is it fitting correctly? Is it too low? Too high? Is that gapping okay? The knee pad isn’t touching the dog’s knee. Is that right? Here are 4 guidelines to follow when fitting knee brace for a CCL injury.
1) Question: Is The Brace Too High Or Too Low On The Dog’s Leg?
To determine where the brace should sit on the leg, first locate the tibial crest and patella. Just between these two points is where the joint axis of the brace should sit. This will align the brace’s mechanical joint with the stifle’s anatomical joint. This enables ease of movement and maximum stability.
Fitting Guideline
A line is drawn on the suspension sleeve indicating where we believe the brace and suspension sleeve should attach to each other according to the cast taken of the dog’s leg. Detach the suspension sleeve from the brace (it is attached with Velcro) and move the brace above or below the line to make the brace sit higher or lower on the dog’s leg.
To determine if the positioning is correct, undo all the straps and put the knee in flexion so that it is bent at around 90°. Bend the brace so that it is also at a 90° angle at the joint. Place the brace onto the dog’s leg while still flexed. This will force the anatomical and mechanical joints to align. Cycle the leg through flexion and extension to ensure proper alignment and there is no excess gapping or pinching. Starting distally and moving proximally, tighten the straps to the proper tightness and cycle the leg through flexion and extension again.
If, when the brace is aligned with the anatomical joint, the suspension sleeve straps should be lying just proximal to the calcaneus on the Achilles tendon. If they are below the calcaneus, then remove the suspension sleeve from the brace and reattach it proximally so that the straps sit just above the calcaneus.
2) Question: Is The Brace Too Tall On The Inside Of The Groin?
If the brace is too tall, the dog can experience irritation in the inguinal area. As the leg flexes and extends, contact with the abdomen could push the brace down, which can cause the brace to slide distally or cause sores on the anterior and posterior areas of the hock.
Fitting Guideline
For dogs 40 lbs. and over, there should be 3-4 finger widths between the top of the brace and the inside of the groin. For dogs 40 lbs. and smaller, there should be 2-3 finger widths. This allows for enough room between the top of the brace and the stomach for flexion and extension of the leg as well as comfort when the dog is sitting or lying down.
If the brace is too tall, the brace will need to be mailed to us so we can trim down the upper cuff of the brace.
3) Question: Why Isn’t The Knee Pad Touching Or Tighter Against The Dog’s Leg?
The knee pad’s function is to resist tibial thrust which occurs when the leg is straight but does not occur when the leg is bent.
The knee pad sits on the tibial crest to resist the tibial thrust at its source. The knee pad will be in contact with the tibia when the leg is fully extended. When the dog is standing or flexing their leg, the knee pad will not be in contact with the leg and may look loose. This gapping is normal.
Fitting Guideline
The knee strap is pre-adjusted with a white line indicating the tightness of the strap. Tighten or loosen the strap accordingly if the knee pad does not meet the tibial crest when the leg is fully extended.
4) Question: Is There Supposed To Be Gapping Between The Brace and The Dog’s Knee?
The gapping around the knee is normal as the muscles around the knee change shape during flexion and extension. Excessive gapping can be caused if the brace is sitting too low or distally on the knee. It that case it may need to be moved more proximally on the suspension sleeve.
Fitting Guideline
If you undo the front knee strap and press the brace back against the dog’s leg, the brace will be in total contact around the dog’s knee. When the knee strap is engaged, it utilizes the entirety of the brace as leverage to press caudally on the tibia. This causes the brace to move forward slightly, creating the gapping of the brace around the knee.
These are general guidelines on the fit of a stifle brace. However, every dogs’ anatomy and brace are unique. If you have any questions or concerns about how a brace is fitting your patient, please email us pictures of the dog wearing the brace and call us to speak with one of our clinicians.