The Wizard's potion
These are some of Don's interesting comments
from the Friday morning case conferences. Any errors in this section are
solely the poor recording of otherwise accurate comments, due to the pressure
of the quantity of interesting comments. This section is updated weekly.
To see the cases
This section has outgrown it's page and been subdivided.
Previous sections are linked below.
This page last updated on
05/06/2003 09:56:57 PM
August 23rd 2002 from Christine Lamoureux
- Subscapularis tears: the definition of a
complete tear is one in which there is no subscapularis tendon attachment to
the humerus; a full-thickness tear does not necessarily have to be complete; a
combination of complete and full-thickness tears can result in displacement of
the biceps tendon into an intraarticular position proximally and
extraarticular position distally, for example.
- Young adult patient slammed hand in a car door
and has masses dorsal to the second and third metacarpophalangeal joints that
are dark on T1 and bright on T2 with fluid surrounding the flexor tendons:
differential includes pannus associated with JRA vs hematoma (but the injury
is subacute), vs multifocal PVNS.
- Haglund’s disease; the "pump bump" comprised
of thickening of the posterosuperior calcaneous and Achilles tendon. This
phenomenon is also associated with superficial Achilles bursitis and
retrocalcaneal bursitis. The differential includes seronegative
- Hypoplastic glenoid neck and a "dentate"
morphology of the glenoid fossa may be associated with multidirectional
instability patterns, secondary OA, and rotator cuff tears. This variant
morphology is often an incidental finding on plain films and is comprised of a
broad glenoid (resembling acetabular dysplasia) and the "dentate," or
tooth-like articular surface. Associated findings include a hypoplastic
humeral head, bowing of the acromion and clavicle (such as may be seen in
Erb’s palsy). It is questionable how many of such cases are symptomatic. There
can also be an abnormal anterior labrum resulting in anterior instability, or
posterior labral pathology with posterior instability. The latter has been
associated with an enlarged labrum separated from the glenoid margin with a
cleft, which may be developmental. According to Dr Hughes, further
characteristics of the hypoplastic glenoid include bilaterality and posterior
angulation of the glenoid with respect to the rest of the scapula.
- Seronegative spondyloarthropathies differ from
RA in that they may be characterized by early marrow edema, bony
proliferation, "whiskering" periostitis and soft tissue swelling ("sausage
digits") before the joint spaces become very abnormal.
- Shoulder MR arthrograms: it is often helpful
to compare the T1 and fluid-sensitive sequences side-by side. A disadvantage
of arthrography is the fact that evaluation of bursal-sided irregularities of
the rotator cuff can be obscured.. These bursal-sided tears are not well
described but can be partial with associated tendon retraction. A "rim-rent"
tear is an articular-sided tear that is described as laminated.
- Stages of idiopathic calcific tendonitis:
first the tendon accumulated calcium, then there is partial extrusion into the
bursa, and finally involvement of the bursa itself. MRI with Gad is useful for
evaluating whether there is associated inflammation to explain a patient’s
- How to distinguish a healing fracture from
osteomyelitis on MRI: a debated issue with no real consensus at our
conference. Dr Resnick mentions literature by Mark Schweitzer re the
usefulness of the T1 sequence. Dr Hughes suggests using T1 fat saturation
images both pre and post-contrast. Dr Pathria suggests "a needle." She states
that T1 pre and post contrast fat sat sequences are useful in the setting of
evaluation of knee arthrograms to evaluate for retears.
- Infarcts (osteonecrosis) of the femoral
condyles: assume that these are related to steroid use or alcohol. Literature
supports that the lateral femoral condyle is more often involved that the
medial. The femur and tibia can both be involved, but involvement of the
patella and fibula is rare. The "double line" sign is a topic of debate:
described at U. Penn as a T1 dark band with inner high T2 signal. Dr Pathria
believes this is a real phenomenon, not due to just chemical shift artifact,
and that the high signal band represents healing. Dr Resnick states that
infarct can be difficult to distinguish from fracture at times, and that an
osteochondral fracture is in the differential when a half-moon shape pattern
of signal abnormality is adjacent to the articular surface if no history is
- Legg Perthes: definition of the "sagging rope"
sign: this may represent a ring-like pattern of osteophytes at the femoral
head/neck junction and may be seen in cases of OA as well. It is unclear if
this sign as described referred to the surface of the femoral head or to
- Be careful when describing calcification in
the region of the distal ulna as within the TFCC as there are many causes of
calcification in this region.
- There is an association of gout with psoriatic
arthritis but not with CPPD.
- Lunotriquetral contact (elongation on a
frontal film) is a secondary sign of partial coalition.
- The elbow has three fat pads: 2 anterior and
one posterior. In a normal lateral radiograph the anterior radial and coronoid
fat pads are superimposed, and the posterior olecranon fat pad is not seen.
- Classic findings in amyloid arthropathy:
shoulder masses ("shoulder pads"), involvement of the wrist resulting in
carpal tunnel pathology, the spine and the hip (can result in pathologic
fractures of the femoral necks).
- In ankylosing spondylitis, the size of
syndesmophytes relates to the degree of facet ankylosis. Also, in AS the
symmetry of the SI joint involvement is overrated as a feature. In the spine,
pseudo-pseudoarthroses may occur when 2 levels are involved without
involvement of the intervening level.
- Hydroxyapatite deposition may occur at one
site and is not necessarily associated with systemic disease. It can appear
unchanged for years or can resolve.
- Gout-associated soft tissue densities may be
secondary to the density of the urate crystals themselves (160 HU) . Saturnine
gout refers to that which was associated with drinkers of moonshine.
- Distal clavicular resection with acromioplasty
is performed in some cases of impingement syndrome. The radiographic
appearance can be confused with distal clavicular resorption secondary to RA,
post-traumatic resorption, hyperparathyroidism or scleroderma (although these
latter 2 processes usually taper it).
August 16th 2002 from Christine Lamoureux
- Rotary Fixation of the Atlanto-axial joint:
plain film findings are a persistent asymmetry of the atlantoaxial space on
the open-mouth view imaged in both obliquities. The lateral mass that is
elevated, foreshortened and closer to the odontoid is the one that has moved
anteriorly. The finding of asymmetry on a frontal view alone is not
diagnostic. CT is useful for evaluation of equivocal findings.
- Silastic Synovitis: fragments of a silastic
implant appear low signal on MRI.
- Amyloid Arthropathy: the case shown
demonstrated cystic changes in the carpal bones and distal radius. This type
of arthropathy was more common 15 years ago that it is today because of a
different type of dailysate that was in use…this process can involve the hip
joints as well, producing "apple core" lesions of the proximal femur.
- Brachial plexus MRI: " Robert Taylor Drinks
Cold Beer" (roots, trunks, divisions, cords, branches (an Andeas gem).
- Case of and enhancing osseous fragment
adjacent to the fibular head with soft tissue inflammation and no history of
trauma: differential includes ossicle in the biceps femoris muscle (more
commonly seen in the lateral head of the gastrocnemius muscle and popliteus
muscle), myositis ossificans (pseudomalignant osseous tumor of the soft
tissues…but no trauma history), soft tissue osteoma or osteochondroma (rare).
Favor a late stage pseudomalignant osseous tumor of the soft tissues (a benign
- Mass in the suprascapular and spinoglenoid
notch consistent with a ganglion cyst with entrapment syndrome: these lesions
can sometimes erode bone and are associated with labral pathology 87 % of the
time according to Auria…
- Biceps tendon completely dislocated from the
bicipital groove: this can be a clinical diagnosis but MRI is useful when the
clinical diagnosis is unclear? The "slingshot" effect is when the tendons of
both the long and short heads rupture and "the biceps ends up below the
elbow." A proximal to distal approach to the pathology of a rupture is
recommended. There are two intraarticular and two extraarticular mechanisms:
Intraarticular: biceps tendon is in the joint,
and there must be a full-thickness tear of the subscapularis
Extraarticular: either transverse ligament
disruption or a partial tear of the subscapularis fibers
- Benign lung nodules can be metastatic from
giant cell tumor and chondroblastoma via direct invasion of the vascular tree.
- Inferior Glenohumeral Ligament Complex: non
fat-suppressed images can be helpful to evaluate pathology in this region.
Discussion re multidirectional instability and difficulty in distinguishing
iatrogenic effects of capsulorrhaphy vs those attributable to trauma.
- Advice re improving our shoulder arthrograms:
a common mistake is to place the needle too medially. The needle needs to be
up against the humeral head before injecting.
July 19th 2002 Ortho
1. Stenner's lesion is a
UCL injury at the thumb MCPJ, such that the ligament is pulled off distally and
ends up superficial to the aponeurosis, so that it will not spontaneously heal.
It gives a yo yo on a string sign. Classically gamekeepers wringing the
rabbits neck, now common in skiers. Both the proper and accesory ligaments
have to be torn to cause a Stenner's. All Stenner's are surgically
repaired. Only rarely does the ligament pull off the metacarpal. can
also be a boney avulsion. If can radially deviate 35 degrees or show
an avulsed boney fragment that is rotated, then this suggests a Stenner's rather
than a simple UCL tear.
2. Various shapes of
acromium: Type 1; flat, Type 2; curved, Type 3; hooked, Type 4;
undersurface bump at level of IS tendon. Possibly developmental, but hooks
occur at the same site as the coracoacromial ligament spurs. Determines
type of surgical excision required for SAD. If the acromium is the cause
of impingement, then it is external impingement.
3. Patella tendon
rupture is usually secondary to repetitive minor trauma and tendinosis/
tendinopathy. Other predisposing factors for tendon rupture are: DM,
Steroids, RhA, SLE, CRF. Possible associations are PCL tear and knee
dislocation. Results in patella alta (as does Marfan's). Grelsamer
Meadows modified Insall Salvati method states that the patella tendon (inferior
tip of patella to tibial tubercle) should not be more than twice the length of
the articular cartilage of the patella. This is independant of flexion and
can be used with plain film or MRI. When repairing the tendon look for
holes in patella or tibial tubercle for either primary repair or supporting box
4. Hip labral tears.
Type 1; morphologically normal, central high signal, Type 2; linear high
signal going to a single surface, Type 3; detached. The ilio femoral
ligament is the inverted V shaped ligament of Bigalow, a very strong ligament.
Clicking hip can be intra or extra articular. Intra; labrum and
degenerated ligamentum teres, extra; Psoas and ITB. ALAB acetabular labral
articular defect is fissuring of the articular cartilage adjacent to a torn
labrum (and is a local secret)
5. Ankle trauma.
SER I; torn
anterior tib fib lig,
SER II; oblique
Fx of fibula (high posterior to low anterior at level of ankle),
SER III; post tib
transverse Fx of tib malleolus or deltoid lig inj.
6. A pillon Fx occurs in
July 19th 2002 Rheumatology
1. Long standing AS of the Cx
spine can have anterior resorption/ scalloping of the bodies.
2. Commonest cause of
secondary HOA is bronchogenic carcinoma, but the condition with the highest
incidence of HOA is pleural fibroma (ass. hypoglycaemia).
3. OA of the hand causes a medial
lateral wavy appearance, but not displaced anterior/posterior.
4. Erosive or inflammatory OA
causes central collapse (erosion) and ankylosis.
5. Gout, CPPD and HAD can all be
deposited in OA joints and cause painful flare ups.
6. Short middle
phalanges can be seen with frostbite, which also cause OA.
7. Rice bodies; RhA, TB