NECROSIS 
part, arifes in the fpongy parts of the bones, and from an 
internal caufe, in young fubjeCts of debilitated and bad 
conftitutions, the difcharge being fetid, copious, thin, 
and fanious. If the bone itfelf be touched with a probe, 
it does not feel dry, as in necrofis, but excavated by 
ulceration, and, as it were, worm-eaten. 
It is a remarkable circumftance in thehiftory of necrofis, 
that, in favourable inftances of the difeafe, the inflexibility 
and firmnefs of the limb are preferved during the whole 
of the procefs by which the new bone is formed. Con- 
feqnently, the new bone muft have begun to grow, and 
mull have acquired firmnefs before the old bone feparates, 
or is abforbed. Were this not the cafe, the limb muft 
become flexible and ufelefs the moment the dead bone is 
removed. Another confequence of the new bone being 
formed before the removal of the old one, is, that the 
former muft furround and include the latter. For, fince 
the lifelefs portion of bone completely occupies the fpace 
between the two living ends, thele cannot be immediately 
connected by the new bony matter. The connexion can 
alone be completed by the new bone being depofited on 
the outfide of the old one, from one end to the other, 
and attaching itfelf to the portion? which ftill remain 
alive. The new bone muft alfo be necefl'arily larger than 
the old one, becaufe externally fituated; and hence the 
affeCVed limb, after the cure is complete, will always con¬ 
tinue larger, clumfier, and lefs fhapely, than the other. 
The length of it, however, remains unaltered, becaufe 
the old bone retains its attachments, while the rudiments 
of the new' bone are lying on its outfide, and conned the 
living ends of the old one by an inflexible mafs, equal in 
length to the portion which is deftroyed. 
According to Mr. Ruflell, an incipient cafe of necrofis 
is charafterifed by a deep-feated excruciating pain, not 
at firft aggravated by preflure, and which is loon followed 
by a rapid enlargement of the parts along the courfe of 
the bone. Soon, however, after the commencement of 
the attack, an external inflammation fucceeds, which 
quickly ends in the formation of matter. The abfcefs 
at length burfts by a fmall opening. The extent of this 
inflammation is not in general great. Moft commonly 
feveral inflammations of a circumfcribed kind occur about 
the fame time ; the abfcefies burft by fmall openings, which 
do not dole, but continue difcharging matter as fiftulous 
fores. The apertures are generally fituated over the moft 
fuperficial part of the affeCted bone. The pus is ufually 
of good quality, and large in quantity, iffuing from ex- 
tenlivecavities, intowhich the fiftulae lead. Such abfcelfes, 
being fituated within the newly-formed offeous Ihell, can¬ 
not be difcharged by preflure, nor can any fluctuation be 
felt. A probe can feldom be introduced far into the 
fiftulous openings, or difeover any loofe piece of bone. 
In this ftage, the dead bone, technically called the 
fequejlnim, can feldom be felt; though, in a few inftances, 
fmall lpiculse make their way outward, together with 
the difcharge. Fiftulous openings may be regarded as 
necefl'arily attendant on all cafes of necrofis. 
After the openings have formed, the cafe may take one 
of the following courfes. The ulcerations may in time 
heal up, the fequeftrum never be feen, and no veftige of 
the difeafe remain, except a permanent enlargement and 
induration along the courfe of'the bone. This is the 
moft favourable manner in which a necrofis may ter¬ 
minate. In the other one, the fequeftrum makes its 
appearance externally, through the new bone and the 
integuments, attended with different degrees of pain, 
inflammation, and fuppuration, in different cafes. The 
fequeftrum may at firft be moved by fhaking it; but is 
too firmly wedged in the furrounding parts to be com¬ 
pletely taken out. In time, however, it becomes loofe 
enough to be removed. Sometimes the middle- portion 
of the fequeftrum prefents itlelf externally, while its tides 
are every-where wedged in the fubftance of the new bone. 
The natural end of fuch a cafe would be very tedious of 
accomplifliment, and the interference of art is effentially 
Vol. XVI. No. 1144. 
ferviceable in accelerating the reparation of the dead bone, 
thus circumftanced. After the fequeftrum has been either 
abforbed or thrown off, in one of the above ways, the 
cavity of the new bone becomes filled , up with granula- \ 
tions, which are, at length, converted into bony matter. 
Thus the new bone differs from the original one, in being 
folid inftead of hollow. 
When the fequeftrum is thrown offflowly, the inflam¬ 
mation is moderate ; but, when it feparates quickly, while 
the new bone is in a foft ftate, the detachment is always 
preceded by fevere inflammatory fymptoms, and followed 
by a temporary lofs of the natural firmnefs of the limb. 
This premature feparation of the fequeftrum often occurs 
in necrofis of the lower jaw, and the chin confequently 
falls down on the neck. In certain cafes, the fequeftrum 
feparates at each end from the living portions of the old 
bone, before the new offeous Ihell has acquired firmnefs, 
fo that the limb feels as if it were broken in two places. 
The tibia, femur, lower jaw, clavicle, humerus, fibula, 
radius, and ulna, are moft frequently affe&ed with necrofis. 
Excepting the lower jaw and fcapula, the procefs of rege¬ 
neration has only been noticed in the cylindrical bones. 
From twelve to eighteen years of age is the time of life 
moft fubjeCt to necrofis. The necrofis of the lower jaw, 
however, feldom occurs before the age of thirty. In lome 
perfons, two bones are affeCted at once, owing to con- 
ftitutional caufes. The procefs of cure is faid to take 
place with more celerity in the lower jaw than any other 
bone, and may be completed in three months. Mr. Ruflell 
has never known a necrofis of the tibia get well in lefs 
than a year; but, in general, nearly two years elapfe firft; 
fometimes the cure is protracted to a much greater length 
of time. 
Necrofis of the lower jaw and clavicle never proves 
fatal: that of the lower extremities, which is the worlt 
cafe, does fo very feldom, and only from the violence of 
the firft inflammatory fymptoms, which rapidly bring on 
a heCtic fever, that proves incurable without removing 
its local caufe by a timely amputation. When the vio¬ 
lence of the firft ftage, however, has abated, the irritation 
ceafes, and the heCtic fymptoms, if there are any, are 
generally moderate. Nor is this ftate of tranquillity dif- 
turbed, till the fequeftrum, in making its way outward, 
again produces irritation. At this fecond period of ur¬ 
gency, extenfive inflammation may originate, ulceration 
ipread all over tiie furface of the limb, affume an unhealthy 
appearance, violent fever fucceed, and the patient either 
perifh, or link., into a ftate in which he muft content to 
amputation as the only means of faving his life. This is 
the laft crifls of imminent danger; but, in general, it i* 
lefs perilous than when the inflammation comes on in. 
the incipient ftage of necrofis. 
The following cafe of necrofis of the thigh-bone is 
related by Dr. Mackenzie:—William Baxter, a boy thir¬ 
teen years old, received a blow on his thigh at fchool, of 
which he at firft hardly complained ; but in a few months 
he began to have pain in the thigh, which inflamed, fweii- 
ed, and appeared to have matter in it. The parents being 
poor, no furgeon was called, and the boy was allowed to 
linger for a great while. At length the matter made its 
way through the fkin, by a fmall opening on the interior 
part of the thigh, about three inches above the knee, and 
a thin fanies continued to be difcharged for eighteen cr 
twenty months. At length, the hole in the fkin enlarged, 
and the point of a bone began to protrude, and give a 
good deal of pain when the clothes rubbed againft it. 
After fuffering in this manner for two years and a half, 
the boy, as he lay in bed one morning, felt the bone 
loofer, and projecting more than ordinary. He gave it a 
ftrong pull, and brought the piece away entirely, which 
proved to be feven inches and a half of the thigh-bone. 
A good deal of bleeding followed; but the wound loon 
healed, and he has never fince found the leaft incon¬ 
venience. Dr. Mackenzie, hearing of this Angular cafe, 
fent for the boy, carefully examined his thigh, and found 
2 II it 
