Internal derangements of the knee-joint : thesis submitted for graduation as M.D. of Edinburgh University, April 1886 / by W. Scott Lang.
- Lang, Walter Scott.
- Date:
- 1887
Licence: Public Domain Mark
Credit: Internal derangements of the knee-joint : thesis submitted for graduation as M.D. of Edinburgh University, April 1886 / by W. Scott Lang. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
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![tion inwards, at the same time pressing the rim of the cartilage inwards with the thumb should it protrude (as it generally does) over the inner tuberosity of the tibia. Flexion removes the anterior portion of the head of the tibia from the femur, and so releases any portion of the cartilage which may have been jammed between the two bones. “ In extreme extension it is the anterior portion of the tibia which is in contact with the femur, in the semiflexed position its middle, and in com- ]dete flexion its posterior edge” (Humphrey on The Skeleton). Flexion will also straighten out the alar pads should they be displaced or doubled upon tliemselves. Kotation of the leg inwards is most important, as it brings the inner condyle of the femur more closely in apposition with its corresponding articular surface of tlie tibia, as already explained. Then, by extending the knee while' maintaining rotation inwards, the internal condyle is kept moving truly in its socket, and does not ride upon too much of the semilunar cartilage. Hey states, in a general manner, that the disorder may arise from “ anything which prevents a condyle of the femur from moving truly in the socket formed for it by the semilunar carti- lage.” And altliough that is nearly all he says regarding the pathology, it accords, as far as it goes, with the theory here pro- pounded. The rotation inwards makes tense the external (anterior) crucial ligament; and Goodsir states, op. cit., that this ligament “guides rotation of the tibia outwards” in order to bring about complete extension. Hence by keeping this ligament tense, the rotatory movement necessary in order to completely extend the joint may be brought about. This same point is referred to by Morris (Anatomy of the Joints, p. 371), where he says, “ ‘ Pronation ’ is limited by external crucial ligament.” Further references to treatment in general will be made after other forms of internal derangement have been described. The External Semilunar Fibro-Cai'tilage.—The anatomical and physiological peculiarities of this body have already been referred to, viz., its smaller size and more nearly circular form, also its greater range of movement; and, keeping these facts in view as well as “ the ordinary use of the joint,” we can readily understand how its complete luxation is possible, and also why its partial or incomplete luxation is more rare than tliat of the internal cartilage. Luxation of this cartilage may be complete or incomplete. Complete Luxation.—Several cases of this variety of internal derangement of the knee-joint are on record, and a drawing of a dissected specimen shown by Mr Godlee, Transactions of the Pathological Society of London, vol. xxxi., may be seen. In the words of Mr Godlee, “ The circumference of the fibro-cartilage has been torn away from its attachment to the capsule of the joint, and it—the external semilunar cartilage—now occupies a vertical position in the intercondyloid fossa.” This case appears to be](https://iiif.wellcomecollection.org/image/b22378650_0015.jp2/full/800%2C/0/default.jpg)
