Frozen Shoulder vs Rotator Cuff Tear: What You Need to Know
As Orthopaedic physiotherapists, we frequently see and treat common shoulder injuries and shoulder conditions.
Two of the most common diagnoses we make in the clinic are frozen shoulder and rotator cuff tears.
In this blog post I’m going to break down a few of the differences between the diagnoses, but at the end of the day with any shoulder injury the goals remain the same for both frozen shoulder and rotator cuff tears.
The immediate treatment goals for the injured shoulder are typically to decrease the pain and inflammation, increase the range of motion, and to strengthen the rotator cuff, upper & mid back muscles.
What is frozen shoulder?
Frozen shoulder, also known as adhesive capsulitis often occurs insidiously (out of the blue), but it can also be triggered by a fall/trauma to the shoulder or immobilization of the shoulder.
It typically occurs in women who are 45-60 years old, which coincides with when most women begin perimenopause and menopause.
It is shocking to me that there’s very little research to back this link up as anecdotally I’ve observed this connection for years, but just recently a group of researchers at Duke University school of Medicine published the study ‘Is Hormone Replacing Therapy Associated with Reduced Risk of Adhesive Capsulitis in Menopausal Women? A Single Center Analysis’. (Saltzman & Wittstein et. al, Jul 2023)
It is hypothesized the decrease in estrogen and other hormones contribute to frozen shoulder. Although the sample size was limited, they found that women not receiving HRT had greater odds of developing frozen shoulder. I hope that this research may lead to further investigations into this interesting correlation.
What happens to the shoulder joint when you have a frozen shoulder?
So what exactly happens inside the shoulder joint when someone develops frozen shoulder or adhesive capsulitis?
Let’s talk about the anatomy of the shoulder joint to begin.
The shoulder joint is a ball and socket joint, but the acetabulum (the socket) is very shallow, so the ball of the humerus (the upper arm) is essentially a golf ball sitting on a tee.
So this makes the shoulder capsule (made up of fibrous connective tissue, ligaments and a synovial membrane) and the muscles/tendons of the rotator cuff VERY important in creating stability and strength of the shoulder.
They are essentially the only things holding your arm to your trunk!
John Hopkins Medicine beautifully describes the mechanism behind frozen shoulder to be when ‘the capsule has become inflamed and scarring develops. The scar formations are called adhesions. As the capsule's folds become scarred and tightened, shoulder movement becomes restricted and moving the joint becomes painful.’ (John Hopkins Medicine, n.d.)
When someone presents with frozen shoulder they can present with varying ranges of restriction. Some people can barely move their arm from their side in any direction without excruciating pain, but others may be only limited in specific directions and closer to end ranges of motion.
Regardless, there are always three phases to frozen shoulder.
The freezing phase, which is the most painful phase, is when people are losing or have lost their ability to move the arm freely in certain directions. This is when the capsule is likely ‘scarring down’. This phase can last from 6 weeks up to a few months. The pain may be dull or sharp and often worsens at night or with activity. It's very common to have pain and stiffness during this stage.
The frozen phase can last from 4-6 months and is typically much less painful, but it’s the phase where the range of motion of the shoulder is significantly reduced, impacting the quality of life and functional abilities of the individual.
The thawing phase can last from 6 months to 2 years and is when the shoulder’s mobility gradually returns and the pain is significantly decreased.
In my opinion, physiotherapy is most helpful to treat frozen shoulder in the freezing phase (phase 1) and the thawing phase (phase 3).
In the beginning, modalities like acupuncture, muscle release and gentle mobilization/range of motion can help to decrease the inflammation and pain.
In the frozen stage, patients are encouraged to do assisted range of motion exercises, but the body simply needs time to heal and repair. The goal is to move your shoulder and maintain, at the very least, range of motion within the joint.
In the thawing phase physiotherapy is very helpful in regaining full mobility, strength and stability. Surgery isn’t really an option for resolution of a frozen shoulder.
What is a rotator cuff tear or rotator cuff injury?
So what about a rotator cuff tear, how does this present and how is it different from frozen shoulder?
The rotator cuff is made up of four muscles that surround the shoulder blade (scapula) and the tendon’s of those muscles blend into the shoulder capsule we talked about earlier, adding to the stability of the shoulder joint.
The most common rotator cuff tendon to be torn is of the supraspinatous. This is the muscle that sits on top of the scapula and exits under the square of the shoulder called the acromion. It sits right beside the long head of biceps which also inserts into the shoulder but isn’t formally considered part of the rotator cuff.
This region in the front of the shoulder is prone to impingement because most folks slouch. In a slouched position, the shoulder blades migrate around the trunk and tip forward, which significantly decreases the space for tendon clearance under the acromion and causes impingement when the arm is raised overhead.
This pinching of the tendon can cause fraying and microtrauma which can lead to a tear over time. Rotator cuff tears can happen in the other three muscles as well - infraspinatous, teres minor or subscapularis.
Tears in the cuff can also occur after a trauma like a fall, when lifting heavier items, when the arm is taken past it’s normal physiological range of motion etc.
With a rotator cuff tear, the patient will often experience a reduced range of motion in a certain plane depending on the muscle injured. Strength and range is typically reduced and pain and inflammation is present with motion.
It is very possible to rehabilitate a tear (acute or chronic) with physiotherapy and exercise without ever needing surgery. A physiotherapist can help reduce the inflammation and pain, help to correct posture, increase range of motion and build strength through acupuncture, Gunn IMS/dry needling, mobilization and exercises.
With some acute torn rotator cuffs, sports medicine physicians may recommend platelet-rich plasma (PRP) therapy. PRP is a treatment option that involves injecting the patient’s own platelets containing growth factors that are believed to aid in tissue repair and regeneration. The idea is that by injecting PRP into the area of the tear, the healing process can be accelerated. It’s typically not covered by extended health insurance but is an option to be discussed with your doctor.
If you have a shoulder injury and need some help with rehabilitation, please feel free to book in with one of our physiotherapists at Resilience Physiotherapy! Our clinic is located in the Toronto Annex area and we specialize in physiotherapy treatment for orthopedic injuries and conditions such as frozen shoulder and rotator cuff tears.
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References:
Saltzman, E., Reinke, E. K., Wahl, E. P., Ford, A. C., Kennedy, J., & Wittstein, J. (2022). Is Hormone Replacement Therapy Associated with Reduced Risk of Adhesive Capsulitis in Menopausal Women? A Single Center Analysis. In MENOPAUSE-THE JOURNAL OF THE NORTH AMERICAN MENOPAUSE SOCIETY (Vol. 29, pp. 1467–1467).
