CASE 3

A 24-year-old male sustained an injury to his right thumb while skiing. He was holding onto a ski pole when he fell going downhill. He immediately developed pain in the right thumb. He was seen at the mountainside and diagnosed to have a sprain. He presented to your office a week later because of ongoing pain and swelling in the thumb. Examination revealed a swollen metacarpophalangeal joint of the thumb, as well as swelling on the ulnar side of the metacarpophalangeal joint.

The most likely diagnosis is:

1. Sprain of the metacarpophalangeal joint

2. Volar plate injury

3. Gamekeeper’s thumb

4. Extensor pollicis brevis rupture

 

Discussion

The correct answer is (C). This is a classic mechanism of injury, and although the description of a classic gamekeeper’s thumb is a chronic injury to the ulnar collateral complex of the metacarpophalangeal joint of the thumb, in contemporary terms any injury to the ulnar collateral complex of the thumb metacarpophalangeal joint is classified as a gamekeeper’s thumb. The more contemporary name for this condition is a skier’s thumb, which implies an acute injury to the ulnar collateral complex of the thumb metacarpophalangeal joint. However, this injury can occur from various mechanisms of injury, skiing being one of them.

The pathoanatomy of gamekeeper’s thumb consists of injuries to which of the following structures?

1. Ulnar collateral complex of the metacarpophalangeal joint of the thumb

2. Volar plate junction with the ulnar collateral complex

3. Dorsal capsule

4. All of the above

 

Discussion

The correct answer is (D). Although classically, the description of the injury is

limited to the ulnar collateral complex of the thumb, one has to remember that the ulnar collateral complex is confluent with the volar plate at the volar ulnar corner and dorsally blends in with the dorsal capsule of the metacarpophalangeal joint. Therefore, in most circumstances an injury which spans the ulnar side of the thumb includes an injury not only to the ulnar collateral ligament itself but also to the accessory collateral ligament and its confluence with the volar plate.

If the injury extends dorsally, which occurs in most cases, the injury also includes the dorsal ulnar corner of the capsule of the metacarpophalangeal joint.

This patient had a swelling which was noted on the ulnar side of the metacarpophalangeal joint, and upon palpation it was a localized globular swelling.

This appearance is typically associated with which of the following?

1. Stener lesion

2. Rupture of the extensor pollicis brevis

3. Rupture and proximal retraction of the volar plate

4. None of the above

 

Discussion

The correct answer is (A). This is the typical clinical description of a Stener lesion. A Stener lesion is an injury of the ulnar collateral complex, which includes the distal avulsion from the base of the proximal phalanx as the thumb gets radial deviation force during the act of the injury. As the deviation force continues, the ulnar collateral ligament, which has now torn off the base of the proximal phalanx, continues proximal retraction and displacement, and the thumb deviates radially. The adductor aponeurosis, which is superficial to the ulnar collateral ligament, now gets interposed between the ulnar collateral ligament and the proximal phalanx base. As a result of this, the distally avulsed ulnar collateral ligament is now superficial to the adductor aponeurosis and may sometimes be rolled upon itself giving a globular appearance, which is clinically palpable on the ulnar side of the metacarpal head. Although this appearance can signify a Stener lesion, it does not always occur, and its absence does not indicate the lack of a Stener lesion.

The most appropriate treatment for this patient would be:

1. Short-arm thumb spica cast

2. Long-arm thumb spica cast

3. Open repair of the ulnar collateral complex

4. External fixation of the metacarpophalangeal joint

5. None of the above

 

Discussion

The correct answer is (C). This patient has a gamekeeper’s thumb with a localized globular swelling over the metacarpal head on the ulnar side, indicating the presence of a Stener lesion. Given the pathoanatomy of the Stener lesion wherein the adductor aponeurosis is interposed between the ulnar collateral complex and the original proximal phalangeal attachment of the ligament, such an injury is highly unlikely to heal and almost inevitably leads to ongoing ulnar-sided instability of the metacarpophalangeal joint. Therefore, extraction of this ligament, re-positioning it deep to the adductor aponeurosis, and repairing it to the base of the proximal phalanx would be the most appropriate treatment so as to establish ulnar-sided stability of the metacarpophalangeal joint.

 

Objectives: Did you learn...?

 

 

Identify clinical presentation of game keepers thumb? Identify the pathoanatomy of gamekeepers thumb?

 

 

Understand the clinical description of Stener lesions? Treatment of Stener lesions?