Thoracic Outlet Syndrome: A Workup Algorithm
Written for referring providers, athletic trainers, and therapists who encounter these patients first.
Thoracic outlet syndrome tends to find us rather than the other way around. By the time these patients arrive, most have carried two or three other diagnoses, failed a course of treatment for each, and begun to feel that nobody believes them.
The difficulty is real. There is no single confirmatory test, the classic provocative maneuvers are unreliable, and the symptoms overlap with cervical radiculopathy, rotator cuff disease, and peripheral neuropathy. What helps is a disciplined, stepwise workup rather than a search for one positive finding.
Much of what follows draws on the diagnostic algorithm published by Wagner and colleagues at Emory.
Who to suspect
The typical patient is an overhead athlete or a worker with repetitive overhead demands. Three features travel together: repetitive overhead activity, a contracted pectoralis minor, and scapular dyskinesia.
The mechanism is mechanical. A shortened pectoralis minor pulls the scapula into a protracted resting position. That protraction narrows the space behind the pectoralis minor where the brachial plexus cords and axillary vessels sit, and it simultaneously tethers the suprascapular nerve at the suprascapular notch. Each problem worsens the other.
Symptoms progress in a recognizable order. Early on, anterior shoulder and upper chest pain with activity. Later, radiating pain into the arm and increasingly obvious scapular dyskinesia. Further along, severe diffuse shoulder pain with posterior radiation as the suprascapular nerve becomes involved, medial scapular pain from scapulothoracic bursitis, and eventually pain reaching the supraclavicular fossa and neck. Most athletes have stopped playing by the later stages.
The workup, step by step
1. History and physical examination
Examine the cervical spine first, to identify radicular findings that would redirect the workup entirely.
Look at the patient from behind with the shirt off. Unilateral scapular protraction is usually visible, with the inferior angle standing off the chest wall.
Palpate for tenderness and a Tinel sign at the pectoralis minor insertion on the coracoid.
Measure pectoralis minor length on both sides, from the medial coracoid to the inferior margin of the fourth rib at the sternocostal junction, with the patient sitting upright. The affected side is usually shorter.
Assess the suprascapular nerve with a stretch test, and check supraspinatus and infraspinatus strength.
A note on the classic maneuvers. Wright's, Roos, and Adson's tests carry high false positive and false negative rates and should not be used to make or exclude the diagnosis. The elevated arm stress test, placing the shoulder in extension with varying abduction to stretch the plexus behind the pectoralis minor, is the more dependable of the provocative tests.
2. Imaging
Imaging is primarily used to exclude other causes rather than to confirm this one.
Cervical and shoulder radiographs, looking for cervical rib, prior trauma, or anomalous anatomy
MRI of the shoulder for rotator cuff, labral, and degenerative pathology that could explain the symptoms
MRI of the brachial plexus for fibrous bands, nerve sheath tumors, or compression
MR or CT angiography using a dynamic protocol with arms up and arms down, to evaluate the subclavian and axillary vessels
3. Electrodiagnostic studies
Useful for ruling out cervical radiculopathy and other peripheral neuropathies. Supportive findings strengthen a suspicion of suprascapular neuropathy, but normal studies do not exclude the diagnosis. These tests cannot confirm thoracic outlet syndrome on their own.
4. Image-guided injections
This is the step that carries the most weight, and it is both diagnostic and prognostic.
Ultrasound-guided local anesthetic is targeted to the suprascapular notch, to the pectoralis minor insertion on the coracoid, or both. Botulinum toxin into the pectoralis minor muscle belly is an alternative. Patients who respond well to injection tend to do better after surgical release, which makes this as much a planning tool as a diagnostic one.
The threshold used by Wagner's group before offering surgery is greater than 80 percent symptom improvement.
5. Rule out vascular TOS before proceeding
This matters because the treatment pathway diverges completely. Vascular thoracic outlet syndrome presents differently, with unilateral arm swelling, cyanosis, Raynaud-type symptoms distally, upper extremity thrombosis, or tenderness concentrated in the supraclavicular fossa. The angiogram with dynamic protocol is what settles this.
The neurogenic form arises behind the pectoralis minor. The vascular form arises in the scalene triangle and the costoclavicular space.
The algorithm:
History and examination consistent with neurogenic TOS, with cervical spine pathology excluded
Radiographs of the cervical spine and shoulder
MRI of the shoulder and MRI of the brachial plexus
MR or CT angiogram with dynamic vascular protocol
Electrodiagnostic studies
Image-guided anesthetic injection to the suprascapular notch, the pectoralis minor insertion, or both
Alternate etiologies eliminated and positive injection response, which confirms the diagnosis
Six months of supervised therapy focused on scapular posture, periscapular and rotator cuff strengthening, and pectoralis minor stretching, with a figure-of-eight brace
Failure of therapy plus a positive injection response, which together establish the surgical indication
Surgical release, tailored to the findings
Staged postoperative therapy over sixteen weeks
Vascular findings at any point redirect the patient to vascular surgery rather than through this pathway.
Treatment
Therapy first, always. Six months of supervised work on scapular kinematics, postural retraining, periscapular and rotator cuff strengthening, and targeted pectoralis minor stretching, with a figure-of-eight brace to hold the scapula retracted. A meaningful number of patients improve here and never need an operation.
Arthroscopic pectoralis minor release. The central procedure, since pectoralis minor contracture is usually the driver. Release of the tendon from the medial coracoid allows the scapula to come out of protraction, which reopens the space behind it.
Arthroscopic suprascapular neurolysis. Release of the transverse scapular ligament and neurolysis of the nerve at the notch, which addresses the traction component and the posterior shoulder pain. Usually performed along with the pectoralis minor release.
Brachial plexus neurolysis and infraclavicular decompression. Release of fibrous bands around the cords and of the subclavius from the undersurface of the clavicle, completing the decompression.
Scalenectomy and first rib resection. These address the scalene triangle and costoclavicular space rather than the retropectoralis minor space, and they belong primarily to vascular TOS and to selected refractory cases. Worth knowing that in the published neurogenic series, patients treated with first rib resection and scalenectomy combined with pectoralis minor release did worse than those who had isolated pectoralis minor release. These are done in conjunction with our vascular surgery colleagues.
Vascular TOS. Managed by vascular surgery. Within Prisma Health we coordinate these referrals directly, and patients with mixed or uncertain presentations are evaluated by both services.
Recovery
Sling for the first two weeks, transitioning to a figure-of-eight brace at the first visit. Range of motion and scapular retraining from two to six weeks. Strengthening from six to twelve. Sport-specific work from twelve to sixteen, with the brace weaned as scapular control returns.
Therapy after surgery is not optional. The release opens the space, and the rehabilitation is what keeps it open.
When to send a patient
Consider referral for an overhead athlete or overhead worker with anterior shoulder and chest pain, visible scapular dyskinesia, tenderness over the coracoid, and symptoms that have not responded to treatment aimed at the rotator cuff or the cervical spine.
Patients with arm swelling, color change, or suspected thrombosis need urgent vascular evaluation rather than a routine referral.
About the author
Joshua R. Eskew, MD is a fellowship-trained orthopedic sports medicine surgeon at Prisma Health's Steadman Hawkins Clinic of the Carolinas in Greenville, South Carolina, and an Associate Professor at the University of South Carolina School of Medicine Greenville. His clinical and research interests include complex shoulder and elbow problems in overhead athletes.
To refer a patient: 864-454-7422 200 C Patewood Drive, Suite 100, Greenville, SC 29615
Reference
Wagner ER, Gottschalk MB, Ahmed AS, Graf AR, Karzon AL. Novel diagnostic and treatment techniques for neurogenic thoracic outlet syndrome. Techniques in Hand and Upper Extremity Surgery. 2023;27(2):100-114.
This post is for general education and is not medical advice.
