Setting fractures and dislocations (al-jabr wal-kasr)

In the fifth fann of Book IV of the Canon, Ibn Sina sets out the art of bone-setting (al-jabr) in three treatises: the first on dislocation and what goes with it, the second on general principles of fracture, and the third on fractures of each part of the body, from the skull, jaw and nose to the collarbone, ribs, upper arm, forearm, thigh, shin and toes ¹. In Book I he had already said that breaks of continuity in large parts are treated by reduction and the fitting bandage, "in the art of bone-setting", and promised the detail in its place ⁴. This record describes what Ibn Sina wrote; it offers no treatment advice.

Ibn Sina defines dislocation (khal') as the complete departure of a bone from its natural place; if the departure is not complete it is called displacement of the joint, which some call wath', and a blow that only bruises the surroundings without moving the bone is wahn ⁵. He ranks joints by how easily they dislocate: the knee is easy because its ligament is lax, the shoulder is near it in thin people, the joints of the fingers and the elbow are hard, and the hip is intermediate ⁵. A sign of dislocation is an unusual hollow in the joint, found by comparing the injured limb with the sound one of the same patient and not with someone else's; if the joint does not move, the dislocation is complete ⁶. He then gives separate chapters on the jaw, collarbone, shoulder, elbow, wrist, fingers, vertebrae, hip, knee, ankle and bones of the foot ⁷.

When a dislocation comes with an ulcer, wound or swelling, he says one must look: if the joint returns with a light pull that does not cause the wound great pain, it is reduced; otherwise the wound is treated first, especially in the large joints, for fear of convulsion ⁶. He tells of a rock falling on a man's shoulder, tearing skin and flesh until the upper arm lay bare. A bone-setter ignorant of his craft aligned the bone, put back the flesh and skin, dressed and bound it, and the flesh turned foul and went bad; that flesh, Ibn Sina says, should have been cut away and the place cauterised with boiling oil ⁶.

Fracture (kasr) is the break in continuity peculiar to bone. He sorts it into the broken into pieces and the even break, across or along, and records names others gave to the kinds. He adds, following Hippocrates (Buqrat), that a broken bone leaning outward is better than one leaning inward, since the nerves there are more numerous ⁸. He denies that a severed marrow is deadly, for the marrow is soft, melted and sticky and is not cut ⁸. In children broken bones can knit; from youth onward a cartilaginous joint forms between the two ends, which he compares to the solder a metalworker runs over a join in copper ⁹. The upper arm is the hardest bone to unite, then the forearm and collarbone, while thigh and shin are easier. He gives times for union: the nose in ten, the rib in twenty, the forearm in thirty to forty and the thigh in fifty, evidently days, since he says the thigh may take three or four months ¹⁰. Among the causes of failure to unite he lists too much fomenting, too frequent unbinding of the bandages, hurrying to move the limb, and scarcity of the sticky blood ¹⁰.

The rule of setting, he says, is to draw the limb by the right measure, for too much brings convulsion, pain and fevers and too little prevents good union; then the two bones are aligned, pads and bandages applied, splints put over them, and the limb kept still. He warns that binding too hard and being slow to loosen can kill the limb, so that it has to be cut off ¹⁰. The bone-setter should run his hand gently over the break to find a displacement, a protrusion or a splinter, and not trust the straightness he sees with his eye, and he should set what is broken the same day, since delay makes it harder and riskier ¹¹. If a splinter must come out, he describes cutting, drilling and sawing with fine tools, noting the danger where a noble part lies behind the bone ¹¹. Splints should be of a material both firm and pliant, such as reed, oleander wood or pomegranate wood, thickest where they meet the break, smooth at the ends; they are put on after five days or more, and the bandages are loosened every other day at first, especially if itching appears ¹². He reports that Hippocrates favoured loosening the bandage one day in two so as not to weary the patient ¹².

Ibn Sina ties bone-setting to the manual operations: he notes that a wound, bleeding, swelling and bruising may accompany a fracture, and that the flesh around it, if not managed to prevent putrefaction, may develop gangrene ⁸. See Surgery, the work of the hand, Anatomy and Medicine.