OCR Text |
Show INJURY OF THE KNEE JOINT. SPHAIN OF THE KNEE JOINT. DISLOCATION OF THE I'ATELLA. THE dislocation of the patella, or knee-pan, is not an un- frequent accident. A man falling, so that the outside of the patella is struck while the muscles of the patella. are not firmly braced, and the limb is nearly extended, suffers this dislocation. From the nature of the accident I have described, it is implied that the bone is dislocated inward. It is most frequently displaced inward, owing to the lesser de~ grec of elevation of the inner eondyle; but it is also driven to the outside of the knee joint sometimes. This dislocation of the patella is easily ascertained, and the reduction is not difficult. The leg is to be extended. and the thumbs applied to the bone, while the fingers grasp the knee joint. If a difiiculty occur it is owing to the liga‘ ment of the patella preventing that bone from surmounting the condyle. In this case, as it is impossible to stretch the ligamentous connexion of the patella with the tibia, so we must have recourse to the further relaxation of the muscles inserted into the patella, and press the patella downward before we attempt to carry it to its place betwixt the condyles. A laced cap for the knee is to be used after the reduction, to hold the patella in its proper place of lodgment. OF THE INJURY OF THE INNER LATERAL LIGAMENT 0F THY KNEE JOINT. THIS is an accident which I do not see noticed. I have seen it in various degrees, and have had an opportunity of ascertaining the state of the parts in dissection. The internal lateral ligament of the knee joint must sufler in a particular manner whenever there is a stress and unusual force upon the joint from a shock perpendicular to the limb. In this plate, A, is the thigh bone; B, the tibia; C, the inner lateral ligament. The force of the trunk bearing on the head of the thigh bone in the direction of the dotted line, must injure, or entirely burst up the ligament at C. So it happens, that a person descending a stair, and thinking that he has come to the landing-place when one step is still to take, falls with the weight of the body bearing on this ligament, and sprains it. How this is most apt to hap- pen to women is evident, considering the greater width of their pelvis, and peculiar obliquity of their thigh bone. For the more removed the thigh bone is from the perpendi- cular, the more apt is the inner ligament to be sprained. If the violence be great, we can readily conceive how the. 'ligament is actually torn, so as to produce A SUBLUXATION OF THE KNEE JOINT. If this accident should occur, which I confess [have not seen. there can be no impediment to reduction. When rm W WWW W"! 7 MP??? |