Practice Essentials
Thumb function constitutes about 50% of hand function as a whole. The thumb metacarpal base is a unique joint that allows a wide range of motion while maintaining stability for grasp and pinch in a variety of positions.
Multiple fracture patterns of the thumb base have been described, including juxta-articular metaphyseal fracture, Bennett fracture, and Rolando fracture. Interest in the fixation of these fractures has been stimulated by the marked decrease in hand function that can develop in the affected patients if disabling arthritis occurs in the thumb carpometacarpal (CMC) articulation as a result of articular incongruity following such fractures. [1, 2, 3, 4, 5]
Rolando fracture initially was described in 1910 in a series of 12 metacarpal base fractures, of which three involved a Y-shaped split of the joint surface. [6, 7] The fracture was described as having the following three major fragments:
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Metacarpal shaft
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Dorsal metacarpal base
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Volar metacarpal base
Since the original description, the term Rolando fracture has come to include essentially all comminuted thumb metacarpal base fractures. [8]
Generally, significant joint incongruity (ie, >1-2 mm of articular stepoff) mandates treatment; however, the type of treatment can vary and has been somewhat controversial. The treatment options initially described focused mainly on closed treatment: either cast immobilization or a short period of splinting followed by early motion to mold joint surfaces. With the advent of internal fixation techniques, especially smaller implants, interest in operative treatment increased over subsequent decades. [9, 10]
For additional information on related fractures, see Metacarpal Fractures, Thumb Fractures and Dislocations, Thumb Dislocation Joint Reduction, Metacarpal Fractures and Dislocations, and Bennett Fracture.
Anatomy
The CMC joint surface consists of two reciprocal interlocked saddles that allow motion parallel and perpendicular to the plane of the palm. Compressive forces across the joint appear to be magnified during pinch and have been estimated at 12 times the pinch force. [11] Articular incongruity, therefore, is subjected to high forces and increases the likelihood of arthrosis development. As a result, there has been considerable interest in finding ways to improve the accuracy and security of reduction techniques.
Pathophysiology
After this kind of injury, the fracture is at risk for further displacement because of the resting tone present in the multiple tendons that act on the thumb. The extensor pollicis brevis (EPB) and the extensor pollicis longus (EPL) shorten the thumb ray, as does the pull of the flexor pollicis longus (FPL). The adductor pollicis tends to pull the distal metacarpal toward the palm, which, in conjunction with the abductor pollicis longus (APL) acting on the metacarpal base, commonly produces varus at the metaphyseal-diaphyseal junction.
Etiology
Rolando fracture is analogous to the pilon fracture of the distal tibia and appears to be secondary to a significant axial load that splits and crushes the metacarpal articular surface. Rolando described two cases that occurred secondary to a fall on the radial side of the hand, with the thumb in adduction, and a third case that was caused by a closed fist, with the thumb folded and held in the palm, striking an adversary's head. [6, 12]
Prognosis
Langhoff et al studied 16 patients who underwent open reduction with fine Kirschner wires (K-wires). [13] At a mean follow-up of 5.8 years, nine patients had no residual symptoms, six had symptoms with moderate activity, and one had significant symptoms necessitating a change in occupation. Eight had reduced range of motion (ROM), and three had a visible deformity of the thenar base region that was related to large residual angulations of 35-55º. Osteoarthritic changes were present in six (55%) of the 11 patients with radiographs at follow-up; this did not appear to correlate with the quality of reduction or with late symptoms.
Proubasta reported the results of five patients treated with a mini external fixator. [14] Pins were placed in the trapezium and thumb metacarpal shaft, and the fracture was reduced with distraction. At short-term follow-up at 3 months, no complications were noted, and the patients all were free from pain and had a full range of thumb movements.
Buchler et al described the management of 13 complex thumb metacarpal base fractures in which multiple fragments were involved. [15] The authors treated the fractures with external fixation between the index and thumb metacarpals and limited internal fixation of the joint surface using pins, screws, or both. They performed bone grafting of the metaphyseal void present after distraction. At follow-up (average, 35 mo), there were no significant complications and no loss of reduction, malalignment, or secondary subluxation. Grip and pinch strength were 81% and 88% of the contralateral side, respectively. Rotation of the thumb metacarpal was 79% of the unaffected side. No diffuse degenerative changes occurred.
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Lateral radiograph of a Rolando fracture. Note how the comminution is not easily viewed on this film.
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Lateral tomograph of a Rolando fracture clearly shows the varus angulation at the fracture, as well as the multiple fragments of the articular surface.
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Anteroposterior tomograph of a Rolando fracture further emphasizes the extent of comminution of the articular surface (same patient as in Image above).
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Radiograph of a healed Rolando fracture following fixation of the articular surface and neutralization with a small plate.
