# Gamekeeper's Thumb > NEET-PG Orthopaedics gamekeeper's thumb covers ulnar collateral ligament tears of the thumb MCP joint, Stener lesion, stress testing and when surgery is needed. - Canonical URL: https://prepelephant.com/topics/neet-pg/orthopaedics/gamekeepers-thumb - Exam / course: NEET-PG · Subject: Orthopaedics - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-14 - Last updated: 2026-10-14 - Reference basis: Green's Operative Hand Surgery; Maheshwari's Essential Orthopaedics; Campbell's Operative Orthopaedics - How to cite: "Gamekeeper's Thumb", PrepElephant, https://prepelephant.com/topics/neet-pg/orthopaedics/gamekeepers-thumb ## Direct answer Gamekeeper's thumb is a tear of the ulnar collateral ligament (UCL) of the thumb metacarpophalangeal (MCP) joint, caused by a forced radial abduction stress. A Stener lesion occurs when the torn distal end of the ligament lies on top of the adductor aponeurosis, which blocks healing. Complete tears with a Stener lesion usually need surgical repair rather than splinting. ## What you must remember - **Ligament:** the ulnar collateral ligament of the thumb MCP joint, which resists radial deviation stress at the joint. - **Mechanism:** forced radial abduction of the MCP, classically from wringing the neck of a rabbit, and in sport from a skier's pole strapped to the thumb, which is the same injury. - **Stress test:** the MCP is stressed radially at about 30 degrees of flexion and compared with the opposite thumb, with a firm end point suggesting a partial tear. - **Stener lesion:** the torn distal end of the ligament, avulsed from the proximal phalanx, is displaced proximally and lies superficial to the adductor aponeurosis, so the two ends cannot approximate. - **Imaging:** radiographs exclude a bony avulsion fragment, and ultrasound or MRI helps show the ligament position. - **Treatment:** partial or non-displaced tears are protected in a thumb spica, while complete tears and Stener lesions are repaired surgically. - **Long-term risk:** untreated complete instability causes pinch weakness and can lead to degenerative MCP joint arthritis. ## A stepwise approach from stress test to repair Gamekeeper's thumb is diagnosed clinically, and the decision to operate depends on the completeness of the tear and the presence of a Stener lesion. Examiners expect the reasoning to run in the order below. 1. **Stress the joint:** apply radial stress to the MCP at about 30 degrees of flexion and compare the opening with the uninjured thumb. 2. **Judge the end point:** a firm end point suggests an incomplete tear, while a soft or absent end point suggests complete rupture. 3. **Image the thumb:** radiographs look for an avulsion fragment at the base of the proximal phalanx, and ultrasound or MRI assess the ligament position. 4. **Look for a Stener lesion:** a displaced ligament end lying over the adductor aponeurosis cannot re-approximate and will not heal with splinting. 5. **Choose the treatment:** non-displaced partial tears are protected in a thumb spica, whereas complete tears and Stener lesions are repaired. 6. **Protect and rehabilitate:** the joint is splinted for a period after repair, then mobilised progressively to restore pinch strength. ## Where the exam tries to catch you Gamekeeper's thumb questions are usually decided by whether the ligament can heal in place or has displaced. - **Trap:** treating a Stener lesion with a thumb spica. **Correct:** the displaced ligament end cannot approximate, so surgical repair is required. - **Trap:** dismissing a thumb sprain as trivial. **Correct:** a complete UCL tear causes pinch weakness and instability, so the stress test and imaging decide whether surgery is needed. - **Trap:** ignoring a radiograph that looks normal. **Correct:** plain films can miss a bony avulsion fragment, so stress views and ultrasound may still be needed. ## Frequently asked questions ### What is a Stener lesion of the thumb? A Stener lesion is a complete ulnar collateral ligament tear of the thumb MCP joint in which the torn distal end lies superficial to the adductor aponeurosis. This displacement prevents the ligament ends from healing together. Surgical repair is usually needed to restore stability. ### Why does gamekeeper's thumb often fail to heal with splinting? Gamekeeper's thumb with a Stener lesion fails to heal with splinting because the displaced ligament end is held away from its origin. The adductor aponeurosis acts as a barrier, so the two ends cannot come back together. Splinting alone is therefore reserved for partial or non-displaced tears. ### How is a complete ulnar collateral ligament tear of the thumb diagnosed? A complete ulnar collateral ligament tear of the thumb is diagnosed by stress testing the MCP joint in radial deviation at about 30 degrees of flexion. A soft end point or marked opening compared with the uninjured side suggests complete rupture. Ultrasound or MRI can confirm the position of the ligament end. ### Is skier's thumb different from gamekeeper's thumb? Skier's thumb and gamekeeper's thumb describe the same injury, an ulnar collateral ligament tear of the thumb MCP joint. The names reflect the mechanism, with a ski pole causing the radial stress in skiers. Management depends on the completeness of the tear, not on the name.