The Erasmus Wilson Lectures ON THE GENERAL PATHOLOGY OF BONE,

MAY 30, 1896. blastoderm. Even when some of the mesoblast has already been formed cells may continue to be budded off from the epiblast, and these, after sinking downwards into the met-oblast, become the originators of cartilage and bone. In ON those fish which have bone in the base of their scales cells of the epiderm produce both the scale and the bone. Cells OF budded off from the epiblastic layer of a salmon embryo have been traced to form the operculum, clavicle, and squamosal. The cartilage of the head of newts, such Delivered before the Royal College of Surgeons of England on as Menobranchus or Necturus, has been also followed back to an origin from epidermal cells,1 March 16th, 18th, and 20th, 1896, Although it may not be possible to demonstrate so clearly the same BY W. G. connexion for the chondroblasts and osteoblasts of higher SURGEON TO THE OUT-PATIENTS AND THROAT DEPARTMENT, "WESTvertebrates, yet it is evident that in them the skull, MINSTER HOSPITAL; LECTURER ON PHYSIOLOGY AT THE lower jaw, and spinal column are very closely conWESTMINSTER HOSPITAL MEDICAL SCHOOL, ETC. nected with the epiblast during development, whilst it is known that the bones of the limbs spring from the same LECTURE I. masses of cells as do the vertebrae. In the first place, thereDelivered on March 16the. fore, the essential characteristic of the osteoblast-viz., the INTRODUCTION. picking out salts of lime from the surrounding medium in order to secrete them in combination with albuminous ME. PRESIDENT AND GENTLEMEN,-Much of that which material-is met with under its simplest form as a function the bones is familiar to all, but interest is chiefly of epiblastic cells. Secondly, cartilage and bone originate
The

Erasmus Wilson Lectures

THE GENERAL PATHOLOGY BONE,

SPENCER, F.R.C.S. ENG.,

No. 3796.

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1472 infected region are born quite an THE EFFECT OF ALTERATIONS IN THE CIRCULATION OF show signs of cretinism after some THE BLOOD THROUGH BONE. All evidence tends to limit the cause of months. In many books one may find bone formation and* bone. cretinism to the water drunk (Kocher). The removal, however, of the thyroid gland from a pregnant bitch is said absorption, hypertrophy and atrophy, hyperplastic and atrophic’ to cause the puppies to be born with "rickets." In some inflammations ascribed both to an increase and also to a. diseased foetuses the thyroid gland has been affected decrease in the amount of blood circulating through the bone. In such different conditions as mollities ossium and osteitis or has been noted to be absent, but in others with apparently similar bone lesions the thyroid gland was normal deformans the same observations may be met with-viz., (Shattock). Therefore, neither disease nor absence of the that the bones were "excessively vascular," "congested,"’ Something is evidently wantthyroid gland can be a general cause of fcetal bone affections. "contained much blood," &c. After birth, however, the thyroid gland becomes such an ing to the explanation when one and the same result,. important factor that both removal and disease, in proportion atrophy, is attributed both to an increased vascularity and two to its severity, check growth of the bones in length. An a diminished vascularity, when an increased vascularity can absolute arrest of growth took place in a boy aged ten after be said to promote both bone formation as well as bone thyroidectomy, so that he was found eighteen years after- absorption. In vascularity as found post mortem there is no, wards to be no taller than at the operation. The removal of distinction between the arterial and venous forms. Observathe thyroid gland from young rabbits and lambs likewise tions have to be made at surgical operations on this point. arrests growth. The epiphyseal ossification ceases, the J.. A slight increase in the arterial blood-supply favours bone. cartilage cells stop proliferating and become either flattened formation and normally occurs in those parts of bone in 7ulticf or distended with fluid. Fibrous tissue grows in from the g1’omth is active -A relatively large supply of blood to any periosteum and so separates the epiphysis functionally from tissue corresponds with physiological activity, and conversely the diaphysis. It is well known that as a consequence of physiological activity necessitates a correspondingly large removal or disease of the thyroid gland affections of the blood-supply. During the years of growth, especially between central nervous system and of the skin occur, forming another ten and seventeen, the greatest activity is at the epiphyseal illustration of the sympathy which connects the bones with and diaphyseal junction. The epiphyseal end of the bone, at the skin and central nervous system. which growth is most rapid, has the greater blood-supply. When in the decline of life the central nervous system The lower epiphysis of the femur, the upper epiphysis of tbssuffers excessive fragility of bone may be found, especially tibia, the upper epiphysis of the humerus, and the lower in insane and ataxic patients. Gigantic overgrowth, epiphysis of the radius are sites. of active grovith. Tha whether of the skeleton as a whole or of part or of the course of the nutrient artery in these bones may be held’ to extremities, may be accompanied by similar overgrowths of favour the blood-supply to the epiphyses above mentioned’. the skin. In the case of the so-called "elephant man" Any injury which tends to separate an epiphysis from its described by Treves there was a hypertrophy of half the diaphysis during the growing period is always attended by skull and of the right upper limb and feet co-existing with the extravasation of much blood on account of the pre.It will be noted that in viously existing vascularity. an enormous hypertrophy of the skin. During the active period off the comparatively simple cases where one or more of the growth the vascularity may be so increased as to be a cause toes or fingers are affected the overgrowth of the bone of actual pain-" growing pains" (Poncet). There can be no is pari passzc with the skin. Further on I shall refer to two doubt, moreover, that it is this special vascularity of growing other points in which bone resembles skin, to the possibility bone which causes the juxta-epiphysary ends to become so of transplanting bone, and the tendency of periosteal frequently the seat of septic inflammations. The greates sarcomata to spread rapidly by way of the lymphatics and the vascularity the more easily will extravasation and thrombosis follow upon a slight injury. The greater the vascularity lymphatic glands like the carcinomata. B. The relation of the bone ma7rom to the vascular systfm the more likely are the micro-organisms which chance and to the lymphadonoid tissues.-The bone marrow cells have to be in the blood to reach to and to settle down in th8’ functions totally different from the osteogenetic cells ; in one blood-clot. The frequency with which boys between thirteen respect, indeed, the action of the latter is the reverse of the and seventeen are attacked by acute inflammations im former, for they absorb bone instead of forming it. Bone is the lower end of the femur or in the upper end of the tibia. absorbed by a process of digestion on the part of the may be compared with the relative freedom from attack on marrow cells ; not only does this process affect the septa the part of girls of the same age. The tendency to ansemia the marrow cavity, but also any foreign bone in consequence of menstruation along with the smaller boneinserted into the medullary cavity is likewise removed. The formation and muscular activity in girls supplies a ready lymphadenoid tissues-the spleen, lymphatic glands, and explanation of the smaller vascular supply and thus the rarer thymus as well as the bone marrow-all originate in close occurrence of septic inflammations. A slight increase of the connexion with the bloodvessels from the splanchnopleural arterial supply to an epiphysis such as results from disease layer of the mesoblast which surrounds the hypoblast of the in the middle of the shaft of the bone may cause a disproporalimentary canal. First of all, some of the cells of the tionate growth of the bone in length. Very rapid growth of splanchnopleure form the walls of the vessels whilst others the bones in length may follow the occurrence of a continuproduce the blood corpuscles. At a later stage lymphadenoid ous fever--e.g., typhoid fever-apparently from the greater tissue arises in the connective tissue around blood capillaries blood-supply to the bones during the course of the fever.. by the white cells which have emigrated collecting in the fine An active use of muscles not only improves their own bloodmeshwork (Gulland). The bone marrow forms from the vessels supply, but also that of the bone to which they are attached-. which push their way into the previously solid cartilages. Thus by muscular exercise the development of the skeleton These structures-the spleen, the lymphatic glands, and as a whole is favoured. But also, as will afterwards be bone marrow-produce red as well as white corpuscles during mentioned, the part of any bone of an adult to which active foetal life. In the adult the production of red corpuscles is muscles are attached has a larger blood-supply than the’ rest. no doubt confined on the whole to the red bone marrow, but B. Any conside’l’able increase of the atrte’l’ial"blooJ-supply to’ whenever a more rapid formation is required—e.g., in order to make good losses by acute basmorrbage—the spleen bone promotes its absorption -1. The absorption of the presupplements the red marrow. The absorptive or digestive: liminary cartilage during the development of bone is brought properties of certain marrow cells is a feature shared inabout by the entrance of bloodvessels from the periosteum, It iss which thus are said to vascularise the calcified cartilage. common with the cells of lymphadenoid tissue. - especially well marked in the lymphatic gland tissuess 2. An absorption of the pre-existing tissue by means of cells surrounding the alimentary canal. I may recall the fact; having digestive or phagocytic properties takes place in conthat Metchnikoff took one of his earliest instances of thE; sequence of the increased arterial blood-supply which constidigestive properties of these cells from those which arE tutes an acute inflammation whether of bone or of the soft found around the alimentary canal of the water flea, Daphnia parts. In the course of operations for acute epiphysitis. whilst later Ruffer described the phagocytic properties oiE surgeons have frequent opportunities of observing how much the cells in Peyer’s patches. It is well known that th< s absorption of bone has happened during the few days that general diseases of the bone marrow are closely allied t< ) the inflammation has lasted. 3. If a foot be wrenched and :’ those of the spleen and to those of the lymphatic glands , so an increased arterial blood-supply or inflammation bethe chief features of which are ansemia or leucocythoemia , brought about in the ligaments, these ligaments will then with new growths such as myeloma and lymphadenoml yield to a force which they would have completely resisted before the inflammation had promoted absorption So, also. (Spencer).

parents living in healthy, and only

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1473 if in order to correct the rickety curve of a long bone a a supposed endemic origin. It has been long known that strain short of breaking be put upon the bone traumatic a case of osteomalacia until then progressing may become inflammation and absorption are caused, so that a week arrested at the climacteric and the bones even’ harden afterwards it will bend or break when the same amount again. Of recent years the climacteric has been artiA slight injury to the ficially induced by removing the ovaries, and this so of force is again applied. limb of a growing boy has been sufficient to cause often that the success of the operation is beyond question bending or fracture some time afterwards on account (Fehling and others). Patients long bed-ridden may soon of the absorption which had in the meanwhile gone be able after double oöphorectomy to get up and walk, 4. The absorption of bone from increased vascu- the bones being again enabled to bear the weight of on. larity is not necessarily connected with inflammation. Nasvi the body. Some important light has been thrown upon the mollities by the examination of the bones of women or the larger angiomata, the true aneurysms of bone, may produce such an increase of the arterial circulation as to dying in the course of normal pregnancy. An increased stimulate the absorptive properties of the osteoclasts. vascularity has been noted especially in the pelvis and When an attack of scurvy causes an increased arterial femora, with signs of increased absorption of bone, so that blood-supply to the periosteum and bone absorption is very many septa were found covered by a layer of decalcified rapid the compact bone becomes very porous or cancellous, fibrous tissue (osteoid tissue). That the pelvis and femora the medullary cavity enlarges, and spontaneous fractures are very vascular, due to an increased arterial blood-supply, When young children are attacked extravasations of in mollities ossium of pregnancy I observed myself in a goat occur. blood take place in the neighbourhood of the epiphyses. In which I examined shortly after it had given birth to a kid. adults there may be so much tendency to absorption as to The animal was suffering from marked softening and bending prevent the formation of any callus should a fracture occur of the pelvis and spontaneous fracture of both femora had during the attack of scurvy. If the scurvy follow shortly occurred. I may here observe that such specimens kept in after a fracture there may be rapid absorption of callus spirit do not preserve the condition existing during life, already formed, so that the fragments again move on one glycerine must be employed instead. In confirmation of the another. Likewise the teeth in such cases become loose and increased arterial supply to the pelvis and femora I may fall out, owing to the absorption going on in the alveoli. refer to the fact that the first signs of mollities ossium in pregnancy are aching pains in these bones, and even Haemophilia also induces excessive absorption of bone. C. A diminution in the arterial blood-snpply checks the during normal pregnancies slight but similar pains in formation of bone whilst absorption continues, so that ’ eccen- the same bones may be met with. Moreover, in confirmatric atrophy" " is brol1ght ab01lt.-As a result of the diminu- tion of the excessive absorption due to the increased tion in the arterial blood-supply the compact bone tends to arterial supply we have the same noted as in the scurvy of become cancellous, and the cancellous bone is in its turn adults concerning the delay or non-union of fractures at that absorbed so that the whole shaft may be reduced to a mere in an otherwise perfectly healthy woman. Definite callus may shell. There is no evidence of any greater rapidity of not form until the termination of pregnancy. Excision of the I absorption than normal. It is the want of a steady forms- knee-joint in a pregnant woman, the cut surfaces being left tion of bone which is the chief factor. As a consequence healthy, was followed by non-union and dislocation backof disuse, whether due to ankylosis of a joint or to paralysis, wards, requiring subsequent amputation. Women who suffer the blood-supply diminishes both to the muscles and to the from osteomalacia have been abnormally fertile. It seems, bones, and hence there follows a marked atrophy of bone. therefore, that the slightly increased vascularity in the pelvis " Eccentric atrophy" regularly occurs as a senile change, and femora attending a normal pregnancy may become in an varying very much in degree in different cases, and the excessively fertile woman further increased, and produces gradual decline in the periosteal bone formation is the more the excessive absorption in the pelvis and femora. Girls about puberty suffer from forms of osteomalacia, indicatmarked the greater the disuse of the muscles. Mollities ossium or osteomalacia.--Mollities ossium has been ing a connexion with the activity of the ovaries but not necessarily with pregnancy. Sometimes the facts so often used as the name for a variety of affections in which a are stated in this way-viz., that the fragilitas ossium common end-viz., softening, bending, and pathological If osteomalacia occur fractures-has been attained in such different ways that occurs most frequently in girls. neither it nor its synonym, osteomalacia, can be applied as in a girl about puberty its course may be arrested and the term for a special disease. It is necessary to distinguish- restoration of the bones brought about by oophorectomy. (a) foetal osteomalacia, which has been referred to; (b) in- Von Recklinghausen considers the increased arterial bloodfantile osteomalacia due to scurvy, which has also been supply amounts practically to an inflammation, so that referred to; (c) rickety osteomalacia arising in childhood osteomalacia from this point of view may be called osteitis and youth from errors in diet or hygiene (vide tM/y) ;; and fibrosa. Osteomalacia is not entirely and exclusively an absorption of bone, for irregular formations of bone, osteo(d) fragility of bone or osteopsathyrosis. Some typical cases of fragilitas ossium may be classed pbytes, &c , have been found. With senile osteo)92,alacia must be classed the osteomalacia as spontaneous pathological variations, a condition which may appear in several members of the same family, for like of lunatics, of atax;a, and other nervous diseases, as well as other spontaneous variations the fragility may be transmitted that occurring in wasting disease, excluding new growth. In to some of the descendants, tending soon, however, to die out. all these cases the "eccentric atrophy,’’—i.e., a diminished Still one can scarcely ever exclude the possibility that other periosteal formation with absorption continuing, is at bottom tendencies to fragility have been present. The occurrence due to impaired general nutrition in addition to disturbance in several members of the same family may be due to a simi- of nerve influence. larity of environment, exposing them to the action of causes The disuse and often allied to those producing rickets. NORTH-EASTERN CHILDREN’S HOSPITAL.-The distortion of the limb following on the multiple fractures, by annual meeting of the governors of this twenty-eighth the muscular reduce the cirlessening patient’s activity, may was held on May 13th at Devonshire House, hospital culation below the normal and so lead to "eccentric the presidency of Mr. J. Listerunder Bishopsgate-street, atrophy." Moreover fragility is the more frequent among Godlee. The deficiency shown on the balance-sheet had been girls about puberty (vide infra). to .62820, and the mortMollities ossi1lm of pregnancy occurs with such frequency reduced during the year from