CHAP. XXXV. Of the whirle-bone of the Knee.
BEfore we part from the Leg, you must remember that there is a bone placed * 1.1 before the ioynt of the Knee [tab. 23. figu. 4. and 5.] which the Grecians call 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, because it lieth vpon the knee; others call it 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉 the Mil∣stone, because it is very like it. Celsus calleth it patella or the Sawcer. It is also very commonly called Rotula, we will call it the Whirle-bone.
It is a bone common to the Thigh & the Leg although it be separated from them both, for it is placed before their articulation. In each knee there is one, somewhat round and broad and ending into a sharpnesse where it resteth vpon the Leg. The magnitude of it is moderate, the latitude scarce two fingers broade, the longitude is somewhat therea∣bouts, the thicknesse is vnequall, for in the extremities it is thinne and growes thicker by degrees, so that in the middest it buncheth out like a compassed buckler, or if you will, like an embowed Looking glasse such as they vsed in ancient times. The vpper part therof * 1.2 groweth to the thicke Tendons of the seauenth, eight and ninth muscles of the Thigh, which by the knee doe runne vnto the Leg: by these Tendons it is established, for they serue it in steade of a Ligament to fasten it both to the Thigh and to the Leg: moreouer on the outside it is couered by them; on the inside it is crusted ouer with a smooth and slippery gristle, at lest the greatest part of it; especially where it reguardeth the Thigh, and this gristle maketh the motion more glib, for it will easily moue vnder a mans finger. Co∣lumbus cannot taste this conceit, but sayeth that it is fastned both to the Thigh and to the Leg by Ligaments of his owne, which sayeth hee doe grow from the Appendices of the Thigh and the Legge, so also sayth Archangelus, yet he doth not deny but it is established by the Tendons of the muscles before spoken of. But Bauhine leaneth more to the first o∣pinion of Vesalius, that it hath no other Ligaments but the Tendons. If these Tendons to which it groweth be cunningly taken away it will appeare both before and in the sides [ta. 24. fig. 4.] rough and full of blind holes, but behinde it hath a moderate protuberation [fig. 5. g h] and shallow bosoms on either side [fig. 5. i k] crusted ouer with a gristle of which the vtter is the larger and the broader.
This protuberation wee spake of, is receiued by the sinus which is betwixt the heads of the Thigh, [f. 1. R betwixt • •] like as the bosome of this whirlebone receiueth the heads of the Thigh; wherefore the Thigh receiueth the whirle & the whirle the Thigh, and so are ioyned by Ginglymos, but the whirle and the Leg-bone are ioyned by adarticulation; * 1.3 wherefore it is moouable least it should make the motion of that ioynt difficile or hard. Moreouer the inner and lower part [fig. 5. L] where it groweth into a processe and regar∣deth the vpper part of the Legge-bone, is rough and perforated that it might growe the faster to the Tendons of the foresaid muscles.
The substance of the whirle is at the first gristly and so remayneth for certain months. Afterward it groweth as hard as a hard Appendix, and at length bony, hard & solid, such as it appeareth in growne bodies, so sayth Falopius in his obseruations, and with him Bau∣hine consenteth; Columbus thinketh it groweth not beyonde the height of an hard Ap∣pendix.
The vse of it is to couer and to firme the laxe and dissolute composition of the ioynt of the Thigh and the Leg, least in progression and walking the Thigh should luxe outward, as also that when we goe downe a hill it might support the ioynt. Moreouer, by the help of the whirle when the knee is gathered directly backward it is bent into a right angle.