Correlation of Acromial Morphology With Risk and Direction of Shoulder Instability: An MRI Study

Authors:

Arner JW, Nolte P-C, Ruzbarsky JJ, Woolson T, Provencher MT, Bradley JP, Millett PJ

Abstract:

Background:

The influence of bony morphology on the development of posterior shoulder instability is not well known.

Purpose:

To determine if acromial morphology, as measured on magnetic resonance imaging (MRI), is associated with posterior or anterior shoulder instability.

Design:

Cross-sectional study; Level of evidence, 3.

Methods:

MRI measurements of posterior acromial coverage (PAC), posterior acromial height (PAH), posterior acromial tilt (PAT), and anterior acromial coverage (AAC) were completed for 3 separate matched groups who underwent surgical intervention: posterior instability, anterior instability, and a comparison group of patients who underwent arthroscopic surgery for snapping scapula. Inclusion criteria were patients with recurrent instability <40 years of age without multidirectional instability, glenoid bone loss >13.5%, or glenoid retroversion >10%.

Results:

Overall, 37 patients were included in each group. PAC was significantly less in the posterior instability group than in the anterior instability and comparison groups (68.3° vs 88.7° vs 81.7°; P < .001). PAH was significantly greater in the posterior group than in the anterior instability group (11.0 mm vs -0.1 mm; P < .001) and comparison group (0.7 mm; P < .001). There was no difference between the posterior and anterior groups in terms of PAT or AAC (P = .45 and P = .05, respectively). PAT was significantly smaller in the posterior instability group than the comparison group (55.2° vs 62.2°; P = .026). The anterior and comparison groups were not significantly different in PAH or PAT (P = .874 and P = .067, respectively) but were significantly different in AAC (P = .026).

Conclusion:

A higher and flatter posterior acromion, as measured on preoperative MRI, appears to be associated with patients who require arthroscopic capsulolabral repair due to posterior shoulder instability. This information may help clinicians to both diagnose and predict the need for operative intervention for patients with posterior labral tears.

You may request the complete study: Correlation of Acromial Morphology With Risk and Direction of Shoulder Instability: An MRI Study

Peter Millett, MD

Average rating:

39 reviews

Alexandra Thompson

Mar 23, 2024

by Alexandra Thompson on Peter Millett, MD

110%

Dr. Millett and his team did a SLAP tear repair and bicep tenodesis on my left shoulder. I use my arms as an artist, and love to swim in the ocean, surf, paddle, and telemark ski. So regaining full use of my shoulder and keeping my bicep attached was very important to me. Now, over two years later, my shoulder has the equivalent range of motion as my other arm and as before the injury, and no pain. After the first three months it felt so good and was so strong that - to my horror - I completely forgot my six-month follow-up.

Not only did Dr. Millett and his team make my arm as good as new, but having had the experience of such kindness and expertise throughout the process of surgery and recovery is like an added shoulder superpower.

Thank you Rita, Brooke, Jason, Sarah, Camille, Olivia, Dr. Millett and everyone! And see you soon when my husband comes in for his knee...

Jeff Chandler

Jan 31, 2022

by Jeff Chandler on Peter Millett, MD

Flawless procedure, Easy recovery

Dr. Millet's repaired my knee and tibia, following a botched operation by a different surgeon. That procedure was virtually pain free and I was weight bearing within a few days. That was 18 years ago and the knee is still strong. A few years after the knee incident, Dr Millet repaired my shoulder. My insurance company approved me for 3 months of disability following that surgery. I was off pain medication in 2 days and had 90% range of motion within a week. I withdrew my disability claim and returned to work within two weeks of surgery. I’m not a famous athlete—just a regular guy. Nonetheless, I was treated like an NFL at the Steadman clinic. Most notable was the time for recovery. Other surgeons perform their hour-long task in the OR and don’t involve themselves in the other functions. Peter and his team manages the entire process from diagnosis, anesthesia, nursing care, and therapy. He takes a holistic approach to patient care and doesn’t skip any steps.

Jenn West

Jul 2, 2021

by Jenn West on Peter Millett, MD

Saved My Life

I went to Dr. Millett after 7 knee surgeries (6 on my right and 1 on my left) and had seen 11 different surgeons who all refused to remove femur metal from my right leg. I am highly allergic to metal and the chronic pain was leaving me bedridden for 3.5wks out of a month. He personally wrote me back on my inquiry, listened to my concerns, scheduled my surgery within a week (due to insurance issues) and personally followed up with my recovery. The level of patient care from Dr. Millett and his ENTIRE team is above any care I have ever received in my 20 years of dealing with orthopedic surgeons. There are not enough words to describe the level of care, dedication and professionalism you receive from Dr. Millett and his staff.
My only disappointment is that I did not find him sooner!!!