Impact of Arthroscopic Lateral Acromioplasty on the Mechanical and Structural Integrity of the Lateral Deltoid Origin: A Cadaveric Study

Authors:

Daniel Cole Marchetti, J Christoph Katthagen, Jacob D Mikula, Scott R Montgomery, Dimitri S Tahal, Kimi D Dahl, Travis Lee Turnbull, Peter J Millett

Abstract:

Symptomatic rotator cuff tears (RCTs) are common, with more than 270,000 repairs performed in the United States each year, 86% of which are performed on patients age 45 and older.1 While the causes of nontraumatic RCTs are multifaceted and poorly understood, distinct variations in the scapular anatomy, such as superior glenoid inclination and a large acromial index, are associated with degenerative RCTs. The critical shoulder angle (CSA) is a radiographic parameter that accounts for both the glenoid inclination and the lateral acromion extension. A CSA >35 has been identified as a risk factor for RCTs, and a CSA <30 is associated with an increased prevalence of osteoarthritis, suggesting that patients with a CSA between these values are at the lowest risk for either condition.

Few studies have looked at how scapular anatomy influences patient outcomes after treatment of RCTs. In one study, patients with a large acromial index who underwent arthroscopic repair of full-thickness RCTs had lower patient satisfaction scores when compared with those with a small acromial index. Furthermore, in a long- term follow-up of patients who underwent latissimus dorsi tendon transfer for irreparable RCTs, patients with a significantly larger CSA reported inferior outcomes.

The fact that the scapular anatomy is not associated only with prevalence of RCTs but is also associated with inferior patient outcomes has led to the idea that an arthroscopic reduction of a large CSA (>35 ) to a favorable range may be beneficial to reduce the risk of primary RCTs, rotator cuff retears, and unsatisfactory outcomes after treatment of RCTs for this patient population.

Anatomical cadaveric studies have demonstrated that the CSA can be significantly reduced by arthroscopic lateral acromioplasty (ALA).16,17 However, there is a risk of potentially damaging the deltoid origin during acromioplasty, which may lead to postoperative deltoid avulsion.18,19 Although it was reported that the deltoid origin was not macroscopically damaged by ALA,16,17 it still remains unclear whether ALA affects the me- chanical integrity of the deltoid. The purpose of this study was to determine whether a 5-mm and/or 10-mm ALA would weaken the structural and mechanical integrity of the lateral deltoid. It was hypothesized that ALA would not significantly affect the failure load of the lateral deltoid origin.

For the complete study: Impact of Arthroscopic Lateral Acromioplasty on the Mechanical and Structural Integrity of the Lateral Deltoid Origin: A Cadaveric 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!!!

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Impact of Arthroscopic Lateral Acromioplasty on the Mechanical and Structural Integrity of the Lateral Deltoid Origin: A Cadaveric Study

Authors:

Abstract:

About the Author: Peter Millett, MD