Left shoulder hemiarthroplasty with glenoplasty and biceps tenodesis.
This is the medical description for the shoulder surgery I had done last July. On the operative report you’ll see the pre/post-operative diagnoses and the operative procedures listed. In this post I’ll aim to correlate the diagnoses with the rationale behind their respective operative procedures.
SHOULDER JOINT ANATOMY
There are several joints that comprise the shoulder girdle and play critical roles, but the most relevant for this surgery discussion is the glenohumeral joint. This is the articulation of the humeral head of the humerus (upper arm bone) and the glenoid fossa of the scapula (shoulder blade). As a simple analogy, this joint can be pictured as an oversized golf ball (humeral head) resting on a small golf tee (glenoid).
Maintaining “glenohumeral joint centration”, or keeping the golf ball centered on the tee, is a crucial component of shoulder health and function. As you can see in the imaging report, prior to the surgery my shoulder had lost that centration. In medical jargon my shoulder would be described as a posteriorly subluxed humeral head on a retroverted glenoid. This means the posterior (back side) of the glenoid fossa had degenerated to the point it was now facing too far towards the back of my body. This caused the resting position of my humeral head to be partially dislocated off of the backside of the glenoid. Or, back to the golf analogy, a beat up driving range golf ball falling off a golf tee missing it’s back lip.
DEGENERATED HUMERAL HEAD ---> HEMIARTHROPLASTY
With respect to a traditional Western medical approach, the disease course of osteoarthritis is irreversible. Therefore, with the presence of complete degenerative arthritis the surgical intervention options were limited, with a joint replacement, or arthroplasty, as my best option. Hemiarthroplasty is the medical term for a partial joint replacement:
- “hemi-“ = partial
- “arthro-“ = joint
- “plasty-“ = replacement/reconstruction
My surgery was only a partial glenohumeral joint replacement as the humeral head was the only component that was replaced. Both my humeral head and glenoid were candidates for replacement as both had arthritic degeneration. However, a composite of factors including my age, boney anatomy, and available implant materials dictated the course of action.
My surgeon explained to me with the current technology utilized in implants, a significant discrepancy in the lifespan of the components. Though the humeral head implant will last my lifetime, the glenoid implant currently has a lifespan of only 12-15 years. The scapula (shoulder blade) is a very thin bone, meaning there is not a significant amount of available bone stock. Each time you do a joint replacement surgery, you have to remove existing bone to create room for the new implant. Therefore, given my age and the limited longevity of the current glenoid implants, I can’t afford to have multiple glenoid replacement surgery revisions in the future.
RETROVERTED GLENOID ---> GLENOPLASTY
As the glenoid replacement was not an option, my surgeon instead did his best to remodel my broken golf tee. He reshaped the surface of the glenoid to make it more “concentric”, or as close to an even tee as possible. Unfortunately, as with the nature of osteoarthritis, there is a degree of degeneration you cannot reverse. And, as I touched on above, there is a limited amount of bone stock in the scapula. Thus, he could not remove too much bone now with my potential of requiring a full glenoid replacement down the road. The typical shape of the glenoid is concave, meaning more depth in the middle with a raised outer rim. The glenoplasty reshaped my glenoid to a more evenly distributed flat surface, which will hopefully allow for better centration of the golf ball back onto the tee.
INFLAMED BICEPS TENDON ---> BICEPS TENODESIS
The biceps muscle has two tendinous attachments in your shoulder. This tenodesis procedure involves the “long head” tendon of your biceps. If we trade the golf tee glenoid analogy for an analog clock, the long head of the biceps would attach just above the 12 o’clock position on the clock face. This allows this head of the biceps to perform both elbow flexion (the classic “show me your muscles” move) and also shoulder flexion (raising your arm above your head). There are several other muscle groups that perform shoulder flexion, rendering the biceps as not an absolutely necessary contributor. Therefore this procedure removed the biceps attachment at the glenoid, and re-attached it to the humerus. This moves the tendon from an otherwise crowded situation and will hopefully allow for decreased inflammation and pain.
So in a nutshell, this surgery replaced a beat up driving range golf ball with a new one, while trying to remodel a broken tee to make it serviceable. To this point it has significantly decreased the constant, deep aching pain I felt in my shoulder. However, as the golf tee is now flat, it has also limited the amount of boney stability available, as I don’t have that outer rim to help keep the golf ball centered. Therefore there is now a significantly increased demand on active and soft tissue structures for my joint stability, most notably my rotator cuff. This has been a fluid and delicate crux of my functional progression throughout rehab, so I’ll dive much deeper into this in future posts.
I did my best to describe and integrate the anatomical and medical concepts in a digestible way. If anyone has any questions on any part of it please let me know, I’m an open book! One of the many byproducts of this process has been how much I’ve geeked out on shoulder anatomy and function. If you, or anyone you know, is struggling with shoulder issues of their own and can’t seem to find answers, please don’t hesitate to reach out! I may not be the ideal model for shoulder health, but I am the ultimate trial and error resource with skin in the game. I have learned, and continue to learn, a wealth of knowledge throughout this journey, so I’d love to help anyone else along theirs.
Much love y’all!
Nate