Summary: A 36-year-old man presented with a painful, swollen right thumb
following a fall. Examination revealed extreme tenderness over the base
of the right thumb. The patient also experienced pain on valgus stress
applied to the metacarpophalangeal joint of the right
thumb.Anteroposterior (AP) and lateral radiographs revealed a
Gamekeeper’s fracture. The patient was treated by immobilization of the
thumb in a spica cast for 4 weeks.
Gamekeeper’s thumb (Skier’s thumb)
AP and lateral radiographs showed a fracture at the base of the proximal
phalanx of the thumb (Figure 1). A small osseous fragment was noted on
the ulnar side of the first metacarpophalangeal (MCP) joint (Figure 2). A
concave defect was noted in the base of the proximal phalanx of the
thumb, consistent with a “donor site.” This location is the attachment
site of the ulnar collateral ligament, one of the 2 collateral ligaments
of the first MCP joint.
Gamekeeper’s thumb is a common injury and is used to describe an
acute or chronic injury of the ulnar collateral ligament of the first
metacarpophalangeal joint. The term was initially used to describe
chronic occupational injuries to the ulnar collateral ligament to
gamekeepers in Scotland because of their methods used to kill rabbits.1
The injury occurred in gamekeepers as they sacrificed rabbits by
breaking their necks with their thumbs and index fingers. Acute injuries
now tend to be more common among skiers and may constitute up to 50% of
hand injuries in these athletes. It may also be seen in patients with
rheumatoid arthritis and suffering from a motor vehicle accident and
other sports injuries resulting from a fall onto an outstretched hand
with an abducted thumb.
The ulnar collateral ligament is a short
ligament that originates from the metacarpal head and inserts onto the
medial aspect and base of the proximal phalanx of the thumb. The MCP
joint chiefly provides flexion and extension movements. Stability to the
joint during activity is provided primarily by the intrinsic and
extrinsic muscles of the thumb. The proper collateral ligament, the
accessory collateral ligament, the palmar plate, and, to some extent,
the dorsal capsule also help to stabilize the MCP joint. The adductors
of the thumb insert onto the extensor expansion through its aponeurosis,
which lies superficial to the ulnar collateral ligament.
injuries of the thumb are ligamentous injuries, usually involving an
avulsion of the ulnar collateral ligament from the base of the proximal
phalanx. The mechanism of the injury involves an acute valgus stress on
the MCP joint during a fall on an outstretched hand.Occasionally, an
avulsion of the bone at the base of the proximal phalanx may result in a
Clinical evaluation and radiographs can be
used to make the diagnosis. Prior to any manipulation of the thumb,
standard anteroposterior,lateral, and oblique radiographs must be
obtained to exclude metacarpal fractures and gamekeeper’s fractures. The
finding of 3 mm of volar subluxation of the phalanx on the metacarpal
is suggestive of complete UCL rupture and instability. Radial deviation
of >40° in extension and >20° in flexion indicates instability.
Stress radiographs obtained with the thumb in the flexed and extended
positions and with valgus stress at the MCP joint can help in
determining the instability of partial tears of the UCL.2
grade I or II sprain without evidence of joint laxity is treated
conservatively. Nonsurgical treatment by immobilizing the thumb in
aspica-type cast for 4 weeks can be considered in partial tears of the
ulnar collateral ligament. A grade III sprain, as a result of a complete
tear with laxity at the MCP joint and angulation >30° to 35°3 results in chronic laxity, pain, loss of grip strength, and eventual degenerative osteoarthropathy.4
Complete UCL tears require surgical intervention. Gamekeeper’s
fractures are usually treated conservatively, but those involving
>30% of the joint surface and those that are malrotated and/or
displaced should not be manipulated. Those fractures are indications for
A Stener lesion5 could also result from this injury. The prevalence of this is variable and in one series was reported at 27%.4
It is a result of the torn end of the ulnar collateral ligament being
displaced and coming to lie superficial to the adductor pollicis
aponeurosis. This lesion also can be associated with gamekeeper’s
fracture, which can be subtle or obvious. Stener lesions may produce a
lump over the medial aspect of the MCP joint, but otherwise they can be
difficult to diagnose clinically. A lump or mass over the ulnar aspect
of the MCP joint should raise suspicion for a Stener lesion if no
fracture is noted on plain radiographs. Plain films, stress views, and
arthrograms, which have been used to diagnose ruptures of the ulnar
collateral ligament, do not provide sufficiently accurate images in
diagnosing Stener lesions.6,7,8,9
The UCL no longer
contacts its area of insertion and due to the interposition of the
aponeurosis between the proximal and distal ends of the torn ligament,
healing in these lesions can be impaired. These lesions are initially
treated conservatively for 6 weeks. If instability still persists
despite conservative treatment, surgery is undertaken. However, if
surgery is undertaken 3 weeks after the initial injury, intervention is
more difficult and the results are suboptimal.10 Complete
tears repaired after 3 weeks tend to have an increased incidence of
weakness and pain on pinch grasp. For this reason, early surgical
intervention is generally undertaken for all cases of ruptured ulnar
Studies have shown the utility of magnetic
resonance (MR) imaging in establishing the integrity of the ulnar
collateral ligament.4,11,12 MR findings can be used after
rupture of the ulnar collateral ligament to distinguish between a Stener
lesion and a nondisplaced or minimally retracted tear. This could
further help to distinguish surgical patients from those who can be
treated nonsurgically.4 Early and accurate diagnosis would
help to avoid unnecessary surgeries and be cost effective, thus
justifying the cost of MR imaging.4
(US) is also considered safe and accurate and is currently being used
for the direct evaluation of the UCL of the thumb. USis a more dynamic
and less time-consuming test than MR and may be easier to perform. Other
disorders, such as tenosynovitis, tendon tears, and articular
pathologic conditions can also be diagnosed with US. In this context,
the authors suggest that US is an underused tool as it is potentially an
adjunct to the clinical examination in the appropriate setting.13
Gamekeeper’s thumb is a common skiing injury. Early and accurate
diagnosis of this injury and its complications can result in better
patient outcomes and decreased long-term morbidity.
- Campbell CS. Gamekeeper’s thumb. J Bone Joint Surgery. 1955;37-B:148-149.
Hannibal M. Orthopedic surgery for gamekeeper’s thumb. Coauthor(s):
Roger D. Medscape.
- Posner MA, Retailaud J. Metacarpophalangeal joint injuries of the thumb. Hand Clinics. 1992;8:713-732.
Hinke DH, Erickson SJ, Chamoy L, Timins ME. Ulnar collateral ligament
of the thumb: MR findings in cadavers, volunteers, and patients with
ligamentous injury (gamekeeper’s thumb), AJR Am J Roentgenol. 163:1431-1434.
- Stener B. Displacement of the ruptured ulnar collateral ligament at the metacarpophalangeal joint of the thumb. J Bone Surg. 1977;59-A: 519-524.
EF Jr, Curtis DJ. Patient-induced stress test of the first
metacarpophalangeal joint: A radiographic assessment of collateral
ligament injuries. Radiology.1986;158:679-683.
- Resnick D, Danzig LA. Arthrographic evaluation of injuries of the first metacarpophalangeal joint: gamekeeper’s thumb. AJR Am J of Roentgenol. 1976:126:1046-1052.
Stener B, Stener I. Shearing fractures associated with rupture of the
ulnar collateral ligament of the metacarpophalangeal joint of thumb. Injury. 1969;1:12-16.
Stener B. Skeletal injuries associated with rupture of the ulnar
collateral ligament of the metacarpophalangeal joint of the thumb. Acta Chir Scand. 1963;125:583-586.
Arnold DM, Cooney W, Wood M. Surgical management of chronic ulnar
collateral ligament insufficiency of the thumb metacarpophalangeal
joint. Orthopedic Review. 1992;21;583-588.
- Louis DS, Buckwaller KA. Magnetic resonanace imaging of the collateral ligaments of the thumb. J of Hand Surg (Am). 1989;14A:739-741.
JA, Abrams RA, Bock GW, et al. Gamekeeper’s thumb: Differentiation of
non-displaced and displaced tears of the ulnar collateral ligament with
MR imaging. Radiology. 1993;188:553-556.
- Ebrahim Farhad
S, Maeseneer Michel De, Jager Tjeerd, et al. US diagnosis of UCL tears
of the thumb and Stener lesions: Technique, pattern-based approach, and
differential diagnosis. Radiographics. 2006; 26:1007-1020.