Clavicle Fracture Malunion & Callus Causing Secondary TOS
In short
A healed broken collarbone can narrow the space beneath it. Learn how clavicle fracture malunion and bony callus cause secondary thoracic outlet syndrome.
In this guide (4 sections)
Clavicle fractures are among the most common traumatic injuries of the shoulder girdle, accounting for five to ten percent of all adult skeletal fractures and approximately forty-five percent of all shoulder fractures. The overwhelming majority of these fractures involve the midshaft (middle third) of the clavicle, positioned directly superior to the costoclavicular space where the brachial plexus cords and subclavian vessels transit. While many clavicle fractures heal uneventfully with conservative sling immobilization or plate fixation, a subset heals with significant malunion, marked shortening, inferior displacement, or exuberant hypertrophic bony callus. This structural deformity directly intrudes into the underlying costoclavicular tunnel, creating a permanent mechanical bottleneck that precipitates secondary neurovascular thoracic outlet syndrome.
Road Traffic Accidents, Scooter Falls, and Sports Trauma in India
In India, road traffic incidents involving two-wheelers, bicycles, and pedestrian falls represent the primary source of traumatic clavicle fractures. Riders thrown from motorcycles or scooters upon hitting unmarked speed breakers or potholes frequently land directly onto the point of their shoulder, sustaining displaced midshaft clavicle fractures. Due to financial constraints or preference for non-operative care, many patients are treated with simple triangular slings or traditional figure-of-eight bandages rather than surgical anatomical fixation. While the bone consolidates solidly, it often heals with significant shortening (exceeding two centimeters) and a bulky downward-pointing callus that begins causing arm tingling months later.
Bony Callus Intrusion, Clavicular Shortening, and Neurovascular Bowstringing
The pathophysiology of post-traumatic thoracic outlet syndrome involves both static bony encroachment and dynamic scapular alterations. A hypertrophic inferior callus acts as an osseous spur that directly indents the subclavian vein, artery, and lower trunk of the brachial plexus against the superior surface of the first rib. Furthermore, clavicular shortening of more than fifteen to twenty millimeters alters the spatial relationship of the entire shoulder girdle. The scapula collapses forward, downward, and inward, causing functional scapular dyskinesis that continuously closes the costoclavicular space during everyday arm movements.
Conservative Management Limitations, Joint Mobilization, and Surgical Referral
Physiotherapy management for post-traumatic thoracic outlet syndrome aims to maximize available anatomical space through conservative means while closely monitoring for objective neurological decline. Conservative rehabilitation focuses on mobilizing the adjacent first rib into depression, releasing hypertonic subclavius and pectoralis minor muscles, and aggressively strengthening the scapular retractors and upward rotators to counteract shoulder collapse. However, if symptoms persist or if progressive motor weakness or arterial compromise develops, surgical intervention, consisting of callus resection, corrective clavicular osteotomy, or first rib excision, is required.
Active Scapular Retraction and Clavicular Offloading Drill
Objective: Retract the collapsed shoulder girdle to expand the costoclavicular space following clavicle malunion
- 1Sit tall with your spine supported, elbows bent at 90 degrees and tucked close to your rib cage.
- 2Hold your palms facing upward in front of you as if holding a dinner plate.
- 3Inhale gently, then as you exhale, slowly rotate your hands outward to your sides while gliding your shoulder blades together.
- 4Consciously feel the front of your collarbone area opening up without letting your lower ribs flare forward.
- 5Hold the open position for 4 seconds, then slowly return to the starting position.
| Anatomical Factor | Low TOS Risk Clavicle Healing | High TOS Risk Malunion Pattern |
|---|---|---|
| Clavicular Shortening | Shortening less than 10 mm; shoulder girdle width and alignment preserved. | Shortening greater than 15-20 mm; significant internal collapse of shoulder girdle. |
| Callus Formation | Smooth, remodeled biological callus confined to the anatomical bone contours. | Exuberant, hypertrophic inferior bony callus projecting into costoclavicular space. |
| Vertical Displacement | Anatomical alignment restored; clavicle elevated safely above first rib. | Inferior displacement of lateral fragment; direct bony abutment on first rib. |
| Clinical Management | Standard post-fracture mobility exercises, rotator cuff and scapular strengthening. | First rib depression, scapular upward rotation drills; consider surgical osteotomy if refractory. |
A jagged bony callus or ununited fracture fragment rubbing chronically against the subclavian artery can cause intimal ulceration and pseudoaneurysm formation months after trauma. Palpate the supraclavicular area for a pulsatile mass and auscultate for a systolic bruit before initiating manual joint therapy.
Frequently Asked Questions
Why did my arm start going numb months after my collarbone fracture healed?
As broken collarbones heal, the body lays down extra bone called a callus. If the bone healed with a large lump underneath or healed shorter than normal, this extra bone can gradually press down onto the nerves and blood vessels traveling into your arm, causing delayed numbness and pain.
Do I need a doctor referral to see a thoracic outlet physiotherapist on BookPhysio.in?
BookPhysio.in does not require a physician prescription. Under the National Commission for Allied and Healthcare Professions (NCAHP) Act 2021, patients across India enjoy direct access to autonomous registered physiotherapists. Through BookPhysio.in, you connect directly with verified clinicians and pay per session with transparent fees, completely free from advance package commitments, commission markups, or platform subscription charges.
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