The term ankylosis implies angular deformity, but is used to designate partial or complete fixation of joints, such fixation being usually accompanied by more or less deformity or displacement. It is a name for a condition and not for a disease, but is always produced by the latter or by injury. The term itself implies nothing as to the nature, extent, or appearance of the exciting cause. The actual cause may have been disease of the joint, of the tissues around it, or may have been the result of injury rather than of infectious or other active disease.
For convenience we speak of fibrous, false, or pseudo-ankylosis, and of that which is bony or actual. A more accurate use of terms would lead us to refer to the former as contracture rather than true ankylosis.
Contractures are the result of acute, usually septic intra-articular and peri-articular processes, where muscle spasm is a pronounced factor and where the intensity of the process has more or less weakened the joint structures. The profession is hardly in the mood to accept acute rheumatism as an infectious process. If true or not the acute rheumatic affections are frequently followed by fibrous ankylosis with contractures. Disfigurements of this kind are often produced as the result of the surface lesions of severe burns or ulcerations, followed by cicatricial contraction and the formation of dense bands and scar tissue. This is a condition which can always be foreseen and which should be guarded against with very great care. (See [Treatment of Burns].) Contractures also occur as the result of certain diseases of the spinal cord, either as the result of active contraction of one set of muscles, or of paralysis, by which the opposing muscles are deprived of resistance and thus draw the limb out of shape.
True ankylosis is sometimes fibrous, sometimes osseous, and occasionally both combined. The older the case the more probable is actual osseous union of joint surfaces. Bony ankylosis implies a sharply destructive type of arthritis, which may have been originally of pyogenic, gonorrheal, or tuberculous character, or else indicates a series of very slow ossific and calcific changes, such as are connected with the osteo-arthritis already described. Many of these cases are to be referred to lesions of the cord, and many of them are of polyarticular character. [Fig. 195], illustrating one of the cases of so-called “ossified men” under the writer’s observation, will portray a series of lesions of this kind, most of the vertebral as well as the other joints being involved in an absolute osseous union.
Fig. 211
Bony ankylosis of hip. (Ransohoff.)
Fig. 212
Bony ankylosis of knee. (Ransohoff.)