THE BURSÆ
Anatomy--Normal and adventitious bursæ--Injuries: Bursal
hæmatoma--DISEASES: Infective bursitis; Traumatic or trade
bursitis; Bursal hydrops; Solid bursal tumour; Gonorrhœal and
suppurative forms of bursitis; Tuberculous and syphilitic
disease--Tumours--_Diseases of individual bursæ in the upper and
lower extremities_.
A bursa is a closed sac lined by endothelium and containing synovia.
Some are normally present--for instance, that between the skin and the
patella, and that between the aponeurosis of the gluteus maximus and the
great trochanter. _Adventitious bursæ_ are developed as a result of
abnormal pressure--for example, over the tarsal bones in cases of
club-foot.
#Injuries of Bursæ.#--As a result of contusion, especially in bleeders,
hæmorrhage may occur into the cavity of a bursa and give rise to a
_bursal hæmatoma_. Such a hæmatoma may mask a fracture of the bone
beneath--for example, fracture of the olecranon.
#Diseases of Bursæ.#--The lining membrane of bursæ resembles that of
joints and tendon sheaths, and is liable to the same forms of disease.
#Infective bursitis# frequently follows abrasions, scratches, and wounds
of the skin over the prepatellar or olecranon bursa, and in neglected
cases the infection transgresses the wall of the bursa and gives rise to
a spreading cellulitis.
#Traumatic or Trade Bursitis.#--This term may be conveniently applied to
those affections of bursæ which result from repeated slight traumatism
incident to particular occupations. The most familiar examples of these
are the enlargement of the prepatellar bursa met with in housemaids--the
"housemaid's knee" (Fig. 113); the enlargement of the olecranon
bursa--"miner's elbow"; and of the ischial bursa--"weaver's" or
"tailor's bottom" (Fig. 116). These affections are characterised by an
effusion of fluid into the sac of the bursa with thickening of its
lining membrane. While friction and pressure are the most evident
factors in their production, it is probable that there is also some
toxic agent concerned, otherwise these affections would be much more
common than they are. Of the countless housemaids in whom the
prepatellar bursa is subjected to friction and pressure, only a small
proportion become the subjects of housemaid's knee.
_Clinical Features._--As these are best illustrated in the different
varieties of prepatellar bursitis, it is convenient to take this as the
type. In a number of cases the inflammation is acute and the patient is
unable to use the limb; the part is hot, swollen, and tender, and
fluctuation can be detected in the bursa. In the majority the condition
is chronic, and the chief feature is the gradual accumulation of fluid
constituting the _bursal hydrops_ or _hygroma_. When the affection has
lasted some time, or has frequently relapsed, the wall of the bursa
becomes thickened by fibrous tissue, which may be deposited irregularly,
so that septa, bands, or fringes are formed, not unlike those met with
in arthritis deformans. These fringes may be detached and form loose
bodies like those met with in joints; less frequently there are
fibrinous bodies of the melon-seed type, sometimes moulded into circular
discs like wafers. The presence of irregular thickenings of the wall, or
of loose bodies, may be recognised on palpation, especially in
superficial bursæ, if the sac is not tensely filled with fluid. The
thickening of the wall may take place in a uniform and concentric
fashion, resulting in the formation of a fibrous tumour--_the solid
bursal tumour_--a small cavity remaining in the centre which serves to
distinguish it from a new growth or neoplasm.
[Illustration: FIG. 113.--Hydrops of Prepatellar Bursa in a housemaid.]
The _treatment_ varies according to the variety and stage of the
affection. In recent cases the symptoms subside under rest and the
application of fomentations. Hydrops may be got rid of by blistering,
by tapping, or by incision and drainage. When the wall is thickened, the
most satisfactory treatment is to excise the bursa; the overlying skin
being reflected in the shape of a horse-shoe flap or being removed along
with the bursa.
#Other Diseases of Bursæ# are associated with _gonorrhœal infection_,
and with _rheumatism_, especially that following scarlet fever, and are
apt to be persistent or to relapse after apparent cure. In the _gouty_
form, urate of soda is deposited in the wall of the bursa, and may
result in the formation of chalky tumours, sometimes of considerable
size (Fig. 114).
[Illustration: FIG. 114.--Section through Bursa over external malleolus,
showing deposit of urate of soda. (Cf. Fig. 117.)]
_Tuberculous disease_ of bursæ closely resembles that of tendon sheaths.
It may occur as an independent affection, or may be associated with
disease in an adjacent bone or joint. It is met with chiefly in the
prepatellar and subdeltoid bursæ, or in one of the bursæ over the great
trochanter. The clinical features are those of an indolent hydrops, with
or without melon-seed bodies, or of uniform thickening of the wall of
the bursa; the tuberculous granulation tissue may break down into a cold
abscess, and give rise to sinuses. The best treatment is to excise the
affected bursa, or, when this is impracticable, to lay it freely open,
remove the tuberculous tissue with the sharp spoon or knife, and treat
the cavity by the open method.
_Syphilitic disease_ is rarely recognised except in the form of bursal
and peri-bursal gummata in front of the knee-joint.
_New growths_ include the fibroma, the myxoma, the myeloma or
giant-celled tumour, and various forms of sarcoma.
#Diseases of Individual Bursæ.#--The _olecranon bursa_ is frequently
the seat of pyogenic infection and of traumatic or trade bursitis, the
latter being known as "miner's" or "student's elbow."
[Illustration: FIG. 115.--Tuberculous Disease of Sub-deltoid Bursa.
(From a photograph lent by Sir George T. Beatson.)]
The _sub-deltoid_ or _sub-acromial bursa_, which usually presents a
single cavity and does not normally communicate with the shoulder-joint,
is indispensable in abduction and rotation of the humerus. When the arm
is abducted, the fixed lower part or floor of the bursa is carried under
the acromion, and the upper part or roof is rolled up in the same
direction, hence tenderness over the inflamed bursa may disappear when
the arm is abducted (Dawbarn's sign). It is liable to traumatic
affections from a fall on the shoulder, pressure, or over-use of the
limb. Pain, located commonly at the insertion of the deltoid, is a
constant symptom and is especially annoying at night, the patient being
unable to get into a comfortable position. Tenderness may be elicited
over the anatomical limits of the bursa, and is usually most marked over
the great tuberosity, just external to the inter-tubercular (bicipital)
groove. When adhesions are present, abduction beyond 10 degrees is
impossible. Demonstrable effusion is not uncommon, but is disguised by
the overlying tissues. If left to himself, the patient tends to maintain
the limb in the "sling position," and resists movements in the direction
of abduction and rotation. In the treatment of this affection the arm
should be maintained at a right angle to the body, the arm being rotated
medially (Codman). When pain does not prevent it, movements of the arm
and massage are persevered with. In neglected cases, when adhesions have
formed and the shoulder is fixed, it may be necessary to break down the
adhesions under an anæsthetic.
The bursa is also liable to infective conditions, such as acute
rheumatism, gonorrhœa, suppuration, or tubercle. In tuberculous disease
a large fluctuating swelling may form and acquire the characters of a
cold abscess (Fig. 115).
The bursa underneath the tendon of the _subscapularis_ muscle when
inflamed causes alteration in the attitude of the shoulder and
impairment of its movements.
An adventitious bursa forms over the _acromion_ process in porters and
others who carry weights on the shoulder, and may be the seat of
traumatic bursitis.
The bursa under the _tendon of insertion of the biceps_, when the seat
of disease, is attended with pain and swelling about a finger's breadth
below the bend of the elbow; there is pain and difficulty in effecting
the combined movement of flexion and supination, slight limitation of
extension, and restriction of pronation.
In the lower extremity, a large number of normal and adventitious bursæ
are met with and may be the seat of bursitis. That over the _tuberosity
of the ischium_, when enlarged as a trade disease, is known as
"weaver's" or "tailor's bottom." It may form a fluctuating swelling of
great size, projecting on the buttock and extending down the thigh, and
causing great inconvenience in sitting (Fig. 116). It sometimes contains
a number of loose bodies.
There are two bursæ over the _great trochanter_, one superficial to, the
other beneath the aponeurosis of the gluteus maximus; the latter is not
infrequently infected by tuberculous disease that has spread from the
trochanter.
The bursa _between the psoas muscle and the capsule of the hip-joint_
may be the seat of tuberculous disease, and give rise to clinical
features not unlike those of disease of the hip-joint. The limb is
flexed, abducted and rotated out; there is a swelling in the upper part
of Scarpa's triangle, but the movements are not restricted in directions
which do not entail putting the ilio-psoas muscle on the stretch.
Cartilaginous and partly ossified loose bodies may accumulate in the
ilio-psoas bursa and distend it, both in a downward direction towards
the hip-joint, with which it communicates, and upwards, projecting
towards the abdomen.
The bursa beneath the quadriceps extensor--_subcrural bursa_--usually
communicates with the knee-joint and shares in its diseases. When shut
off from the joint it may suffer independently, and when distended with
fluid forms a horse-shoe swelling above the patella.
In front of the patella and its ligament is the _prepatellar bursa_,
which may have one, two, or three compartments, usually communicating
with one another. It is the seat of the affection known as "housemaid's
knee," which is very common and is sometimes bilateral, and, less
frequently, of tuberculous disease which usually originates in the
patella.
[Illustration: FIG. 116.--Great Enlargement of the Ischial Bursa.
(Mr. Scot-Skirving's case.)]
The bursa _between the ligamentum patellæ and the tibia_ is rarely the
seat of disease. When it is, there is pain and tenderness referred to
the ligament, the patient is unable to extend the limb completely, the
tuberosity of the tibia is apparently enlarged, and there is a
fluctuating swelling on either side of the ligament, most marked in the
extended position of the limb.
Of the numerous bursæ in the popliteal space, that _between the
semi-membranosus and the medial head of the gastrocnemius_ is most
frequently the seat of disease, which is usually of the nature of a
simple hydrops, forming a fluctuating egg-or sausage-shaped swelling at
the medial side of the popliteal space. It is flaccid in the flexed, and
tense in the extended position. As a rule it causes little
inconvenience, and may be left alone. Otherwise it should be dissected
out, and if, as is frequently the case, there is a communication with
the knee-joint, this should be closed with sutures.
[Illustration: FIG. 117.--Gouty Disease of Bursæ in a tailor. The bursal
tumours were almost entirely composed of urate of soda. (Cf. Fig. 114.)]
An adventitious bursa may form over the _lateral malleolus_, especially
in tailors, giving rise to the condition known as "tailor's ankle"
(Fig. 117).
The bursa _between the tendo-calcaneus (Achillis) and the upper part of
the calcaneus_ may become inflamed--especially as a result of
post-scarlatinal rheumatism or gonorrhœa. The affection is known as
Achillo-bursitis. There is severe pain in the region of the insertion of
the tendo-calcaneus, the movements at the ankle-joint are restricted,
and the patient may be unable to walk. There is a tender swelling on
either side of the tendon. When, in spite of palliative treatment, the
affection persists or relapses, it is best to excise the bursa. The
tendo-calcaneus is detached from the calcaneus, the bursa dissected out,
and the tendon replaced. If there is a bony projection from the
calcaneus, it should be shaved off with the chisel.
The bursa that is sometimes met with on the under aspect of the
calcaneus--_the subcalcanean bursa_--when inflamed, gives rise to pain
and tenderness in the sole of the foot. This affection may be associated
with a spinous projection from the bone, which is capable of being
recognised in a skiagram. The soft parts of the heel are turned forwards
as a flap, the bursa is dissected out, and the projection of bone, if
present, is removed.
The enlargement of adventitious bursæ over the head of the first
metatarsal in hallux valgus; over the tarsus, metatarsus, and digits in
the different forms of club-foot; over the angular projection in Pott's
disease of the spine; over the end of the bone in amputation stumps, and
over hard tumours such as chondroma and osteoma, are described
elsewhere.