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Excerpt from Hand, Fracture and Dislocations: ThumbSynonyms, Key Words, and Related Terms: thumb CMC dislocations, thumb CMC fractures, Bennett fractures, Bennett's fractures, Rolando fractures, Rolando's fractures, skier's thumb, gamekeeper's thumb Please click here to view the full topic text: Hand, Fracture and Dislocations: ThumbThis article offers a detailed review of injuries of the thumb. The topics covered include the following:
For excellent patient education resources, visit eMedicine's Breaks, Fractures, and Dislocations Center. Also, see eMedicine's patient education articles Broken Finger, Finger Dislocation, and Broken Hand. History of the Procedure: The incidence of thumb trauma is difficult to accurately determine. Possession of a functional opposable thumb is of primary importance in the function of the hand and upper extremity. The thumb is said to contribute 40% of hand function. Problem: An opposable thumb was an integral development in the advancement of the human species and remains an important factor in functioning within today's technology-driven society. Thumb injury may lead to a high level of disability in a person's professional and personal life, leading to the loss or reduction of innumerable productive hours in the workplace as well as impairment in the patient's activities of daily living. Etiology: Thumb injury results from both direct and indirect trauma. Injuries most frequently result from falls, occupational injuries (eg, industrial accidents), or athletic injuries. Pathophysiology: Thumb phalangeal fractures Thumb phalangeal fractures consist of both distal and proximal phalanx fractures. These fractures generally are diagnosed and treated identically to phalangeal fractures of the other digits. Distal phalanx fractures can be separated into extra-articular tuft fractures and intra-articular tendon avulsion injuries. Tuft fractures generally are caused by a crush injury to the distal thumb. Tuft fractures frequently are associated with nail bed injuries and are technically open fractures when a nail bed injury is present. Tendon avulsion injuries are often secondary to avulsion of the extensor tendon at its terminal insertion into the distal phalanx. The tendon may pull off a fragment of bone resulting in a "bony" mallet thumb deformity. The flexor pollicis longus, in contrast to the finger flexors, also can be avulsed at the musculotendinous junction. Proximal phalanx fractures consist of fractures of the phalangeal head and shaft. These are treated similarly to phalangeal fractures of digits 2-5. Mallet thumb This is a rare condition, frequently occurring as an open injury secondary to laceration of the distal portion of the extensor tendon. Closed mallet thumb injuries are uncommon. Mallet thumb is defined as an avulsion of the extensor tendon with or without a bony fragment at its distal phalangeal insertion. The mechanism of closed injury is usually secondary to an acute forceful flexion of the thumb IP joint leading to partial or complete tear of the extensor tendon near its insertion. Thumb IP dislocations The IP joint of the thumb functions as a hinge (trochlear) joint with motion primarily in the plane of flexion and extension. Collateral and accessory collateral ligaments as well as the trochlear shape of the joint provide IP ..... Please click here to view the full topic text: Hand, Fracture and Dislocations: Thumb |
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