16: Perilunate Injuries

PROCEDURE 16 Perilunate Injuries



Brad Pilkey



image


Combined Dorsal and Volar Approach




Indications



image The combined dorsal-volar approach allows one to address every aspect of the injury pattern.

image The dorsal approach to the carpus gives the best exposure for open reduction of carpal malalignments, reduction and fixation of fractures, and scapholunate interosseous ligament repair. It is usually the first approach in combined dorsal-volar approaches.

image The volar approach is used to decompress the carpal tunnel, to reduce an irreducible dislocation if needed, and to repair the volar capsular rent.



PITFALLS



• Irreducible lunate dislocations cannot be addressed with only a dorsal approach (i.e., lunate trapped in carpal tunnel).

• We are unable to decompress the carpal tunnel or repair the disrupted volar capsule through a dorsal approach.



Controversies



• For perilunate and trans-scaphoid perilunate dislocations, many different approaches have been described. Operative approaches include the isolated dorsal, the isolated volar, and the combined dorsal-volar.



Treatment Options



• Closed reduction is performed early to restore overall carpal alignment, and to reduce pain and swelling, until such a time that an open reduction and repair can be done.

• Closed reduction and percutaneous pinning is extremely difficult in a perilunate dislocation, due to the inability to maintain anatomic alignment during the stabilization maneuver.

• In a trans-scaphoid injury, an anatomic closed reduction is virtually impossible (Kozin, 1998).


Examination/Imaging



image Diagnosis can be challenging with physical examination alone. Injuries can be missed 25% of the time (Herzberg et al., 1993).
• The wrist is typically swollen and deformed.

• The digits are usually semiflexed with decreased passive motion.

• Median nerve compression findings are common.

image Standard posteroanterior and lateral radiographs are obtained to make the diagnosis. Findings may be subtle. Oblique or traction views may give additional information about the pattern of injury.
• Lateral radiograph
♦ The lateral radiograph is examined for a lack of co-linearity between the radius, lunate, and capitate.

♦ An increased scapholunate angle (>70°) is consistent with scapholunate dissociation.

♦ In stage III perilunate instability, the capitate is usually displaced dorsally from the lunate.

♦ In stage IV perilunate instability, the lunate dislocates from the radius, usually in a volar direction. It rotates volarly (“spilled teacup sign”) (Green et al., 1980) (Fig. 1).

• Posteroanterior radiograph
♦ The posteroanterior radiograph is examined for any disruption of the smooth arcs formed by the proximal aspect of the distal carpal row and the proximal and distal aspects of the proximal carpal row (Gilula et al., 1984) (Fig. 2).

♦ The lunate may appear triangular as opposed to its usual trapezoidal shape.

Related posts:

6: Open Reduction and Internal Fixation of Intra-Articular Fractures of the Distal Humerus 1: Open Reduction and Plate Fixation of Displaced Clavicle Fractures 7: Supracondylar Humeral Fractures 18: Femoral Neck Fractures: Arthroplasty 8: Terrible Triad Injuries of the Elbow 5: Humeral Shaft Fractures

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Jun 7, 2016 | Posted by in ORTHOPEDIC | Comments Off on 16: Perilunate Injuries

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