Thumb MCP Joint · UCL & RCL
Thumb Ligament
Injury
The ligaments of the thumb may be injured with acute (immediate) injuries or slowly over time (chronic attenuation). Because the thumb is involved in almost every grip, an unstable thumb joint changes what the whole hand can do.
Call our office · (623) 264-3300The Two Ligaments That Stabilize the Thumb
Both sit at the thumb metacarpal-phalangeal (MCP) joint — the knuckle closest to the web space.
Ulnar Collateral Ligament (UCL)
The ligament on the side toward the index finger. It is the one that most often ruptures during athletic injury, and it does the most work resisting a pinch.
Radial Collateral Ligament (RCL)
The ligament on the side toward the back of the hand. Occasionally injured, and it contributes to stability on the other side of the same joint.
Overview
What Happens When the Thumb Ligament Is Injured
The ligaments of the thumb may be injured with acute (immediate) injuries or slowly over time (chronic attenuation). Acute injuries to the thumb metacarpal-phalangeal joint (MCP joint) may occur after falling or during athletics such as basketball, football, or skiing.
The ulnar collateral ligament (UCL) often ruptures during athletic injury. Occasionally, the radial collateral ligament (RCL) may be injured.
The decision regarding nonoperative versus operative treatment is complex and should be discussed with your treating physician.
Why This Joint Matters
The MCP joint is where the thumb bends closest to the web space, and its ligaments hold the joint in place when you pinch. When the ligament is stretched or torn, the joint can shift under load — which shows up as pain, weakness and a feeling that the thumb gives way.
How the Injury Happens
- A fall onto the hand with the thumb bent outward
- Skiing, where the pole strap holds the thumb as you fall
- Basketball and football, from contact or a caught ball
- Gradual stretching over time from repeated loading
Acute vs. Chronic
Acute Injury
A single event. The ligament ruptures, and the joint becomes unstable right away.
Chronic Attenuation
The ligament stretches gradually over time. Stability is lost slowly, and the problem can be easier to overlook.
Treatment
Non-Operative & Operative Treatment
Treatment may involve splinting to allow for healing, or surgery when the injury is more severe. The choice depends on the examination.
Non-Operative Treatment
Treatment may involve thumb spica splinting (immobilization) to allow for healing, followed by subsequent mobilization under the guidance of a physician.
- Thumb spica splinting to immobilize the joint while it heals
- Graduated mobilization afterward, guided by your physician
- Hand therapy to restore pinch strength and motion
Nonoperative treatment also carries risks and benefits which should be discussed with your treating physician.
Operative Treatment
With more severe injuries, a physician may discuss surgical treatment instead of nonoperative treatment after a physical examination of the thumb.
- Surgical repair, which may involve the placement of a bone anchor to reattach the ruptured ligament
- Ligamentous reconstruction for chronic injuries, utilizing a tendon graft
- Post-operative splinting and a staged return to activity
Outcomes after surgery vary and risks and benefits should be discussed in detail with your treating physician.
Repair vs. Reconstruction — Why the Timing Matters
An acute rupture can usually be repaired by reattaching the ligament to bone. A chronic injury has no ligament left to reattach, so reconstruction with a tendon graft is used instead. This is one reason a thumb that stays unstable for months is treated differently from one injured last week.
Evaluation
How the Injury Is Assessed
The examination is the main tool for deciding between nonoperative and operative treatment. How much the joint shifts under stress is often the deciding factor.
Physical Examination of the Thumb
The physician stresses the joint to gauge how much it shifts, and compares it with the other thumb.
X-rays
Imaging checks for an associated fracture or a small piece of bone pulled away with the ligament.
Timing of the Injury
Whether the injury is acute or chronic determines whether repair or reconstruction is the right approach.
Related Areas
Thumb injuries often overlap with other conditions of the hand and thumb base.
Common Questions
Thumb Ligament Injury FAQs
What is a thumb ligament injury?
The ligaments of the thumb may be injured with acute (immediate) injuries or slowly over time (chronic attenuation). Acute injuries most commonly involve the ulnar collateral ligament (UCL) at the thumb metacarpal-phalangeal (MCP) joint.
How do these injuries happen?
Acute injuries to the thumb MCP joint may occur after falling or during athletics such as basketball, football, or skiing. Chronic injuries develop gradually as the ligament stretches and attenuates over time.
Which ligament is usually involved?
The ulnar collateral ligament (UCL) often ruptures during athletic injury. Occasionally, the radial collateral ligament (RCL) may be injured.
What is the non-surgical treatment?
Treatment may involve thumb spica splinting (immobilization) to allow for healing, followed by subsequent mobilization under the guidance of a physician.
When is surgery considered?
With more severe injuries, a physician may discuss surgical treatment instead of nonoperative treatment after a physical examination of the thumb.
What does surgical repair involve?
Surgical repair may involve the placement of a bone anchor to reattach the ruptured ligament. With chronic injuries, physicians may discuss ligamentous reconstruction techniques involving the utilization of a tendon graft.
Precision Hand and Orthopedic Surgery
An Unstable Thumb Is Worth Evaluating
If your thumb gives way when you pinch, or pain after an injury has not settled, an evaluation can determine whether the ligament has healed or needs treatment.
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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 12/9/2021 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.