Medial Shoulder Instability
What is it and how does it happen?
This is an injury to the muscles that hold the front limb against the body and includes a number of muscles where they attach at the inside of the shoulder (the subscapularis, teres, latissimus and glenohumeral ligament may be involved).
This injury occurs most often when a dog is running or playing with rapid turns, in sports this can be during agility or bite work. At home, this might be due to running and slipping on wooden floors or jumping off of furniture while in a turn.
How does it present to us and how is it diagnosed?
A low grade tear or sprain includes stretch and inflammation of the muscles and tendons and is often amenable to care with supplements, short-term anti-inflammatories and care with a rehabilitation team for restoration of flexibility and strength of those muscles over 30-60 days. It is important to note that the lameness may resolve after a week or two but it takes time and exercise to rebuild strength and stability.
This may present as a low grade lameness that comes and goes over a few weeks and may initially respond to anti-inflammatories and then may not respond after a week or so.
A medium grade tear includes stretch and destruction of some of those muscle and ligament fibers that creates laxity when the shoulder is examined and can be seen with arthroscopic surgery.
These dogs are often sore in the inside of the shoulder and all of the muscles around the shoulder as they are being used to try to keep the shoulder stable.
A diagnostic ultrasound is often recommended to evaluate joint health and to look for concurrent shoulder strains in the other tendons, arthroscopy is the best definitive way to diagnose this condition if it is medium grade strain/tear.
Depending on the degree of laxity we may order hobbles for these dogs to create support while the delicate muscle fibers are trying to heal back together for 4-12 weeks. These patients should be examined by a rehabilitation doctor every 2-4 weeks and have treatments to improve spine flexibility weekly as the hobbles can create compensational pain if not addressed properly.
These dogs often have laxity due to repeat shoulder injury and should be monitored and managed for arthritis with exams every 6-12 months and annual radiographs + supplements to slow the process of arthritis.
A severe medial shoulder injury may involve enough damage to the muscles, ligaments and joint capsule that overt laxity is present with joint instability. These patients may benefit from surgical stabilization by a large suture. They will require a longer rehabilitation period to restore shoulder muscle stability and will likely have arthritis to manage long-term.
Treatments and Rehabilitation:
After we determine the need for ultrasound, arthroscopy or surgical repair has been determined we can proceed with the rehabilitation and recovery plan:
To improve the healing capacity of this grade of injury, shockwave and stem cells may be recommended sometime during the first 30-60 days of the recovery process, pending exam and results of current therapy.
The full healing process may be 4-6 months in cases where the tear is medium to severe. There is not a great way to speed healing aside from making sure they are comfortable and weight bearing in specific exercise that strengthens the joint - it is important that they see a doctor for pain relief at least monthly to keep up on this. Conversely, if the dog is not weight bearing well due to discomfort, these tissues will not heal, and are at high risk of reinjury. Talk to your veterinarian sooner versus later if you think your dog may be having a set back.
Supplements and medications:
It is important that these patients are not kept on an anti-inflammatory long-term to allow tendon healing (if they have arthritis elsewhere, consider Galliprant as least inhibitory).
For pain relief we often use: Methocarbamol and possibly Galliprant if we believe a nerve injury may also be present. Supplements like CBD may also be considered.
For nutritional healing of tendons and muscles we often incorporate: Adequan or Dasquin with MSM + Caneva + Myos
Weight management to fit/skinny weight is essential in the success of these patients.
Exercise: activity and restrictions
Since it takes weeks to months to get the shoulder muscles and tendons to heal, it is counterproductive to let these dogs run, jump down, skid, or chase balls or bunnies during this time. It is advised to keep them on a leash for 90 days or until they have 100% normal and comfortable flexibility and strength in basic exercises.
After the lameness resolves, short leash walks for 10-15 min are the way to start, increasing by 10 min every week.
The first and most important exercise is: 3 legged-stand See example on this website if you are ready to start right away and start with only the back feet until our rehab team has a chance to teach you more.
https://drmarieshealthydogs.com/must-read-3-exercises-for-your-dog-daily
We look forward to helping you through this process, many dogs come back to normal with rehabilitation therapy and when the follow the plan. Dogs that don’t rebuild their body with symmetry and strength often have long-term recurring injuries. We are so glad you are here!