Dupuytren's Fracture

DUPUYTREN'S FRACTURE (Dupuytren), described by D. is a fracture of the medial malleolus in combination with a fracture of the fibula, usually 6-8 cm above the malleolus. In English, such fractures are called "Pott's fracture." The mechanism of occurrence of these fractures is forced abduction combined with rotation of the foot outward or inward. Often, plantar or dorsal flexion is also added. At the moment of sharp abduction, damage occurs first on the inner side: rupture of the deltoid ligament (more rarely), avulsion of the apex of the medial malleolus, fracture of this malleolus at its base (most frequently). With further abduction of the foot, the talus presses with its outer edge on the inner surface of the lateral malleolus, which usually breaks at the level of the attachment of the anterior lateral malleolar ligament or above this ligament (see vol. VII, art. 458, figure 3). In individual cases, the fibula breaks below the attachment of the anterior tibiofibular ligament; such a fracture is called a low Dupuytren's fracture and approaches so-called bimalleolar fractures [see separate table (vol. VII, art. 675-676), figure 4]. Depending on the mechanism and force of action, D. p. can be accompanied by displacement of the foot in one direction or another, and therefore they can be conveniently divided into a) simple D. p. without displacement of the foot, b) fractures with lateral or posterior displacement of the foot, c) fractures with both of the indicated displacements and tibiofibular diastasis. Clinically, simple fractures without displacement cause swelling and bleeding around both malleoli, while the lateral malleolus is painless, but palpation of the fibula in the lower third is extremely painful. Deviation of the foot is not observed, and mobility in the joint may be only slightly limited; there is only slight plantar flexion. Fractures with lateral or simultaneous posterior displacement of the foot have great practical significance in that, in the absence of reduction, extremely unfavorable static conditions arise due to incongruence of the articular surface of the talus and the tibia. Posterior subluxation of the foot usually occurs in the presence of a marginal fragment of the tibia, which has serious significance for the subsequent function of this joint. Much less often in D. p., a fracture of the anterior edge of the tibia and anterior subluxation of the foot occurs. The mechanism of such subluxation usually consists of sharp dorsal flexion of the foot. D. p. with tibiofibular diastasis can be with or without displacement of the talus backward and outward. With the mechanism of sharp dorsal flexion and abduction of the foot combined with its internal rotation, the medial malleolus, part of the epiphysis, a wedge-shaped fragment, or the attachment of the anterior tibiofibular ligament can be avulsed from the tibia. For the occurrence of diastasis, it is necessary that the line of fracture of the fibula passes at the level or along the attachment of the anterior tibiofibular ligament. Clinically, D. p. complicated by posterior or lateral subluxation of the foot presents a more complex picture than a simple fracture. In addition to swelling and bleeding in the area of both malleoli, there is usually a valgus equinus position, expressed to a greater or lesser extent. Abnormal lateral mobility of the foot can be established and deviation of the heel backward can be observed so that the anterior edge of the tibia protrudes more than in the norm. Such deviation of the heel backward, especially difficult and incomplete reduction and the tendency to shift backward, speaks for the possibility of a fragment of the posterior edge of the articular surface of the tibia and posterior subluxation. This sign is extremely important for the practicing physician. Treatment of a simple D. p. consists in preventing the formation of equinus position by means of a posterior or lateral splint, early movements, and massage. In fractures with lateral or posterior displacement of the foot, as well as with the rarer anterior displacement, early reduction is mandatory. The latter can be performed either manually under local anesthesia (novocaine 1%) or by means of repositioning lateral traction. Manual reduction requires creating a sharp varus position, and in the presence of simultaneous posterior displacement of the foot, a repositioning movement from back to front is necessary with good dorsal flexion. After manual reduction, the corrected position is maintained by a posterior or U-shaped splint. Correction by traction is achieved by creating a varus position and dorsal flexion of the foot. Such a position produces a repositioning action by itself. After the disappearance of pain, active movements of the foot are possible. Prevention of the equino-valgus position constitutes the main task in the treatment system. Old D. p. with the foot in valgus position and subluxation of the talus require surgical treatment, which may consist, depending on the case, in reconstructive surgery on the joint itself or in supra-malleolar osteotomy. In milder cases, abduction of the foot is also well helped by an insert creating a varus position. The same insert is necessary at the end of treatment of fresh D. p., where there was subluxation of the foot. In addition to the valgus position, with hypercorrection and long fixation in a plaster cast, cases with a sharp varus position are observed, which often combine with limited mobility in the ankle joint. This circumstance is also extremely unfavorable from a functional point of view and requires subsequent correction. Cases of deforming arthritis are also noted with improperly united fractures. Severe functional disorders in the presence of limited mobility in the joint sometimes require arthrodesis in a convenient position, which relieves pain. Usually arthrodesis is the last resort. Early reduction and early functional treatment are the best prevention of severe deformities in D. p.