Tips for managing 4 common soft-tissue finger and thumb injuries
After examination and, in some cases, imaging, most of these injuries can be managed conservatively with splinting or injection. Some cases require prompt surgical referral.
PRACTICE RECOMMENDATIONS
› Treat trigger finger with a corticosteroid injection into the flexor tendon sheath. A
› Refer a case of jersey finger to a hand surgeon within 1 week after injury for flexor tendon repair. C
› Treat mallet finger with strict distal interphalangeal joint immobilization for 6 to 8 weeks. A
› Treat Grades 1 and 2 skier’s thumb with immobilization in a thumb spica splint or a cast for 4 to 6 weeks. B
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
In chronic cases, the UCL can be injured by occupational demands and is termed gamekeeper’s thumb because it was first described in this population, who killed game by breaking the animal's neck between the thumb and index finger against the ground.16,18 A UCL tear causes instability at the thumb MCP joint, which affects a person’s ability to grip and pinch.2,16,18
Presentation. On exam, the affected thumb is swollen and, possibly, bruised. There might be radial deviation and volar subluxation of the proximal phalanx. The ulnar side of the MCP joint is tender to palpation.16 If the distal UCL is torn completely, it can displace proximally and present as a palpable mass over the ulnar side of the MCP joint, known as a Stener lesion.16
Stress testing of the MCP joint is the most important part of the physical exam for skier’s thumb. Stabilize the metacarpal neck and apply a valgus stress on the proximal phalanx at both 0° and 30° of MCP flexion (FIGURE 3), which allows for assessment of both the proper and accessory bands of the UCL.2,16 (A common pitfall during stress testing is to allow the MCP joint to rotate, which can mimic instability.2) Intra-articular local anesthesia might be necessary for this exam because it can be painful.16,18,26 A stress exam should assess for laxity and a soft or firm endpoint; the result should be compared to that of a stress exam on the contralateral side.16,17
Imaging. AP, oblique, and lateral radiographs of the thumb should be obtained to assess for instability, avulsion injury, and associated fracture. Subluxation (volar or radial) or supination of the proximal phalanx relative to the metacarpal on imaging suggests MCP instability of the MCP joint.16,17
If the stress exam is equivocal, magnetic resonance imaging is recommended for further assessment.2,18
Continue to: Stress radiographs...
