DISLOCATION, the displacement of one bone from another with which it forms a joint. Thus by dislocation a limb is said to be put out of joint. Dislocations are the result of either disease, accident or congenital malformation. The displacement may be either partial or com plete and cases are classified as simple, when the skin remains unbroken, and compound where a wound lays bare the bone; when a fracture of the bones and injury to important blood ves sels aggravates the case, the dislocation is said to be complicated.
The general treatment of dislocations con sists in reduction, that is, drawing back the displaced joint into its socket. The contracted muscles oppose this reduction, and sometimes their spasmodic action has to be overcome by the administration of chloroform or ether. Up to the year 1870 or thereabouts the reduction was generally effected by extension, that is, by pulling out the displaced limb and stretching the restraining muscles until they are exhausted, when the bone would generally slip back into its place with an audible snap.
Of late years, however, reduction by exten sion has been to a very large extent given up in consequence of the general adoption of re duction by manipulation. This method, known it seems from ancient times, but curiously neg lected, consists in executing certain complex movements of the dislocated limb which effect the return of the displaced bone to its socket by ingeniously utilizing its unruptured attach ments and evading the opposition of the mus cles, by ingenuity rather than by force. It is
particularly applicable to the hip, which, as it is commanded by the strongest mass of muscles in the body, always presented the most formidable obstacles to the old method. The first paper on this subject which attracted general attention was by Dr. Reid of Rochester, N. Y. (1851) ; and in 1869 Professor Bigelow of Boston pub lished a careful and exhaustive discussion of injuries to the hip, with such full and clear di rections for the manipulation method, as to se cure its general adoption in the case of this joint by surgeons in Great Britain as well as in America. The method, however, had been de scribed and used in France and elsewhere, though with less care and precision, in the earlier half of the 19th century.
In cases of congenital dislocation of the hip bone and other congenital misplacements of the bones, manipulation, intensified into powerful massage, has been developed practically to a wonderful extent by numerous surgeons.