Wrist · Tendon Instability
ECU Tendon Instability
The extensor carpi ulnaris tendon is stabilized into a groove on the distal ulna by a subsheath. When that subsheath is injured, the tendon can become unstable — producing ulnar-sided wrist pain with a snapping sensation during rotation.
Call our office · (623) 264-3300The Tendon's Path
The ECU tendon runs along the dorsal ulnar aspect of the wrist.
A subsheath holds the tendon within that groove. When the subsheath is injured, the tendon may become unstable.
Overview
How the Tendon Becomes Unstable
The extensor carpi ulnaris tendon resides along the dorsal ulnar aspect of the wrist, extending upon a groove of the distal ulna and thereafter inserting on the base of the small finger metacarpal.
The tendon is stabilized into its groove upon the distal ulna through a subsheath. This subsheath structure may become injured leading to tendon instability.
Individuals may notice pain along the ulnar aspect of the wrist with a snapping sensation that occurs as the wrist and forearm are rotated.
What Patients May Notice
- Pain along the ulnar (pinky) aspect of the wrist
- A snapping sensation as the wrist and forearm are rotated
- Symptoms related to instability of the tendon within its groove
The Role of the Subsheath
Tendons that change direction around a joint are held in place by a retinacular structure. For the ECU tendon, that structure is the subsheath within the ulnar groove. It allows the tendon to glide while keeping it seated — so when the subsheath is injured, the tendon can slip out of its groove and snap back, which is what produces the sensation patients describe.
When to Seek Evaluation
If you are noticing ulnar-sided wrist pain with a snapping sensation during rotation, an evaluation can help determine whether the ECU subsheath is involved.
Request an AppointmentTreatment Options
Stabilizing the Tendon
In patients with instability and associated pain or dysfunction, surgical treatments involving stabilization of the subsheath or reconstructive stabilization procedure may provide benefit.
Conservative Treatment
The decision regarding nonoperative versus operative treatment is complex and should be discussed with your treating physician.
Nonoperative treatment also carries risks and benefits which should be discussed with your treating physician.
Subsheath Stabilization
Surgical treatments may involve stabilization of the subsheath or a reconstructive stabilization procedure.
- Stabilization of the subsheath
- Reconstructive stabilization procedure
- Aims to secure and stabilize the ECU tendon while allowing for appropriate gliding
Preserving Glide
The goal of these procedures is not simply to hold the tendon down — it is to secure and stabilize the ECU tendon while allowing for appropriate gliding, so the tendon can still do its job of extending and deviating the wrist.
Outcomes after surgical treatments vary and risks and benefits should be discussed in detail with your treating physician.
Snapping on the Pinky Side?
If you notice a snap along the ulnar side of your wrist when you rotate your forearm, an evaluation can determine whether the ECU subsheath is involved.
Request an AppointmentCommon Questions
ECU Instability FAQs
Where is the ECU tendon?+
The extensor carpi ulnaris tendon resides along the dorsal ulnar aspect of the wrist, extending upon a groove of the distal ulna and thereafter inserting on the base of the small finger metacarpal.
What holds the tendon in place?+
The tendon is stabilized into its groove upon the distal ulna through a subsheath. This subsheath structure may become injured leading to tendon instability.
What does ECU instability feel like?+
Individuals may notice pain along the ulnar aspect of the wrist with a snapping sensation that occurs as the wrist and forearm are rotated.
What surgical options exist?+
In patients with instability and associated pain or dysfunction, surgical treatments involving stabilization of the subsheath or reconstructive stabilization procedure may provide benefit. These procedures aim to secure and stabilize the ECU tendon while allowing for appropriate gliding.
Is surgery always needed?+
No. The decision regarding nonoperative versus operative treatment is complex and should be discussed with your treating physician.
Other causes of ulnar-sided wrist pain include ulnocarpal impaction and TFCC injuries.
Precision Hand and Orthopedic Surgery
Ulnar-Sided Wrist Pain With a Snap?
If rotating your wrist or forearm produces a painful snap, an evaluation with Tanay Amin, MD, FAAOS can determine whether the ECU tendon is unstable and which options are right for you.
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Disclaimer: This information is not intended to convey, substitute or supplant any medical advice. In order to establish a treating relationship, please schedule and complete your visits with a licensed physician.
Copyright 12/15/2021 Tanay Amin, MD. Do not copy, distribute, or publish this article. Please contact Precision Hand and Orthopedic Surgery PLLC with regards to any inquiries or corrections.