Revolutionizing Thoracic Outlet Syndrome Diagnosis and Treatment in Throwing Athletes
Thoracic Outlet Syndrome (TOS) is a complex condition affecting athletes, particularly many throwing athletes, due to the repetitive overhead motions inherent in sports like baseball. I was lucky enough to have a recent interview with the TOS guru, Dr Robby Bowers who is the Team Physician for the Atlanta Braves. He and the staff at Emory have pioneered a novel approach to diagnosing and treating nTOS.
The diagnostic portion focuses on using diagnostic injections to become sniper specific on the exact cause and location of the nerve compression. Then, we can ensure a more sniper specific treatment is used for each athlete’s specific issue. Previously, TOS has had a poor diagnostic process due to multiple factors including: usually having normal imaging and nerve studies as well have very unreliable clinical tests. Due to this, the standard diagnosis was primarily made using patient history of symptoms and those poor tests. This typically led 2 treatments:
-Physical Therapy with an unclear plan of where the compression was occuring
-Surgical procedure including a Scalenectomy, First rib resection, and in some cases a Pec Minor releases. (Shotgun approach to: Take out 1st Rib and Scalenes, release of the Pec Minor)
What is Thoracic Outlet Syndrome?
Neurogenic TOS which make up more that 90% of TOS cases, occurs when nerves the brachial plexus becomes compressed—either in the space between the collarbone and the first rib OR underneath the Pec Minor. This can lead to symptoms such as:
Pain in the neck, shoulder, or arm
Numbness and tingling in the fingers
Weakness in the hand or arm
“Baseball Symptoms” can include: Poor feel of the baseball and hand intrinsics or poor control/repeatability of ball release (when it was previously non issue)
Traditional treatment often involves PT or a more invasive surgery, such as first rib resection and scalenectomy, which carry significant risks and lengthy recovery times.
A New Approach: A Focus on the Pectoralis Minor (When indicated by the diagnostic injections)
Dr. Bowers’ work at Emory University has challenged traditional notions of TOS. His hypothesis centers on the pec minor’s role in compressing neurovascular structures, especially in throwing athletes. Over time, the repetitive internal rotation and overhead motion during throwing can lead to adaptive shortening and fibrosis of the pec minor. This tightness narrows the retropectoral space, contributing to TOS symptoms.
Supporting Evidence:
Postural Changes: Throwing athletes often exhibit a protracted posture on their dominant side, narrowing the pectoralis minor space.
Ultrasound Elastography: In a pilot study of college pitchers, Dr. Bowers found significantly increased stiffness in the throwing arm’s pec minor compared to the non-throwing arm.
Ultrasound in Layback: Use of diagnostic ultrasound to view the compression of the nerves in these more throwing specific positions
Diagnostic Innovations
TOS diagnosis is notoriously challenging due to:
Poor reliability of physical examination tests
Normal findings on imaging and nerve conduction studies
Dr. Bowers employs ultrasound-guided diagnostic injections as his gold standard:
Pec Minor Injection: A numbing agent is injected around the pec minor and nerves running under it. Then, he has the athlete go throw that same day (assuming that is their symptom Generator) and assess symptoms
Scalene Injection: A similar process is performed for the scalenes.
These injections need to be done separately to provide clarity on which structure is causing the problem. If one of these is the causative structure, the changes in symptoms should be drastic. This precision avoids the “shotgun approach” of traditional treatment.
Treatment Options
Non-Surgical:
Physical Therapy (PT): Focuses on either Scalene or pec minor stretching, scapular mechanics, and strengthening the lower trapezius
Botox Injections: Temporarily relax the pec minor or Scalene, allowing PT to be more effective by reducing reflexive spasms and decreasing tone. Effects can last approximately three months.
Surgical: (Typically, this is only after failure of Non-Surgical)
1st Rib Resection (If Scalene/1st Rib are identified as the compression site)
The surgery involves removing part or all of the first rib and resecting or releasing the scalene muscles (anterior and sometimes middle) to decompress the thoracic outlet and alleviate pressure on nerves and blood vessels.
Surgical Approach: Typically performed via a transaxillary (through the armpit) or supraclavicular (above the collarbone) incision, depending on the surgeon's preference and the patient’s specific anatomy.
Arthroscopic Pec Minor Release: (If Pec Minor is Identified as the compression site)
A minimally invasive procedure that releases the tight pec minor.
Outpatient surgery with significantly reduced morbidity compared to first rib resection.
Return-to-throw timeline as early as six weeks post-operation.
Comparative Outcomes:
For MLB players, traditional first rib resection has an average return-to-play timeline of 10 ( +/- 4 months. *Arnold Study), with a 81% success rate. In contrast, arthroscopic pec minor release has shown faster recovery times and promising return-to-play rates in individual cases although in a much smaller sample size. More data collection needs to be done.
The Importance of a Multidisciplinary Team
Dr. Bowers credits the success to a collaborative team approach:
Vascular surgeons for first rib resections when necessary.
Orthopedic surgeons specializing in arthroscopic procedures.
Physical therapists for comprehensive rehabilitation.
Conclusion
I have personally had the frustration of leading an athlete through the process of TOS diagnosis and surgical procedure. With the previous methods that were being used, it was hard for me to be confident that this was the correct diagnosis and therefore if the surgical intervention was even addressing the correct issue for that athlete.
This process using diagnostic injections really became interesting to me after that process and I really liked that idea of becoming sniper specific with the assessment and diagnostic process.
Obviously, it is still early in terms of data collection, but the early signs and results are very promising. I view Dr Bowers and company as the top resources for nTOS if you are looking for a more specific and systematized process.
