Preprocedural Evaluation
Tests for joint stability are mandatory before reduction is attempted and after reduction is successfully accomplished.
Perform a full neurovascular examination.
Perform a digital or wrist block.
Perform an active evaluation of joint stability. Have the patient actively range the affected digit through its full range of motion (ROM). If the patient can demonstrate full ROM without displacement, joint stability is sufficient.
Perform a passive evaluation of joint stability. Have the patient place the affected finger in full extension. Place mild radial and ulnar stress on each collateral ligament. Place volarly directed stress to gauge volar plate stability. Repeat radial, ulnar, and volarly directed stresses with the affected finger in moderate flexion, as well. If displacement does not occur during this evaluation, joint stability is sufficient.
Plain radiographs should be obtained before reduction is undertaken (to exclude a concomitant fracture) and again after efforts to reduce the dislocation or subluxation. When a dislocation or subluxation is identified on radiograph, it is described according to the location of the distal segment relative to the proximal segment. (See the images below.)
Thumb metacarpophalangeal (MCP) joint dislocation. Image courtesy of David T. Schwartz, MD.
Dorsal distal interphalangeal (DIP) joint finger dislocation (lateral view). Note small fracture fragments.
Equipment
Anesthetic equipment includes the following:
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Lidocaine (without epinephrine for digital blocks)
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Syringes
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Needles (25-27 gauge)
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Alcohol
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Povidone-iodine solution
Splinting material includes the following:
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Padding for under the cast (eg, Webril)
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Preformed splinting material (eg, plaster of Paris)
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Tape
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Scissors
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Bucket
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Warm water
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Aluminum digital splints
Patient Preparation
A digital block (or, possibly, a wrist block) should be performed before any attempts at reduction.
Each finger is supplied by two sets of nerves (dorsal and palmar digital). These nerves originate from the deep volar branches of the ulnar and median nerves. The palmar digital nerves run alongside the phalanx at the 4-o’clock and 8-o'clock positions, supplying the volar aspect of the digit. The dorsal digital nerves run alongside the phalanx at the 2-o’clock and 10-o'clock positions. The palmar digital nerves of the second through fourth digits additionally supply the dorsal distal aspect of the finger, including the fingertip and nail bed.
A regional partial wrist block (ie, block of the nerve that supplies sensation to the affected finger) may be considered. A wrist block provides a larger area of anesthesia than is required for a simple finger dislocation.
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Thumb metacarpophalangeal (MCP) joint dislocation. Image courtesy of David T. Schwartz, MD.
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Dorsal distal interphalangeal (DIP) joint finger dislocation (lateral view). Note small fracture fragments.
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Distal interphalangeal (DIP) joint dorsal splint.
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Proximal interphalangeal (PIP) joint dorsal splint.
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Volar finger splint.
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Dorsal finger splint.
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Joint reduction for a dorsal dislocation. Video courtesy of Therese Canares, MD; Marleny Franco, MD; and Jonathan Valente, MD (Rhode Island Hospital, Brown University).
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Joint reduction for a volar dislocation. Video courtesy of Therese Canares, MD; Marleny Franco, MD; and Jonathan Valente, MD (Rhode Island Hospital, Brown University).
