transient migratory osteoporosis

1. TRANSIENTMIGRATORY OSTEOPOROSIS
Transient osteoporosis is a rare, self-limiting syndrome, characterized by sudden
onset of jointpain followed by local osteopenia after severalweeks, with
spontaneous healing.
EPIDEMIOLOGY:
1. Middle-aged men between 40 and 60 years old.
2. In women, it occurs almostexclusively during the third trimester of
pregnancy (mean gestational age at onset: 32 weeks) or in the early
postpartumperiod, and tends to be commonly seen in primigravidas.
3. In a few cases, it may be bilateral or recur with a second pregnancy
4. Women to men ratio 3:1
RISK FACTORS:
1. Pregnancy
2. Osteogenesis imperfect
ETIOLOGY:
No consensus in literature for the etiology.
1) NEUROGENICTHEORY(Curtiss and Kincaid) – Possibleintermittent
compression of the mother’s obturator nerve by the child’s head
OBJECTION: Could not be experimentally reproduced in dogs.
2) THEORY OF DISUSE: Osteopenia follows thedisusecaused by the patients
functional impairment.

2. OBJECTION:
i. Demineralization takes place in a very limited
joint area without affecting the rest of the
extremity.
ii. Complete recovery of bone density has been
documented although the involved extremity was
non weight bearing.
3) NONTRAUMATICTYPEOF REFLEX SYMPATHETICDYSTROPHY:
FAVOR: Clinical, radiological, and scintigraphic appearances of
both pathologies are similar.
OBJECTION: Lacks vascular and cutaneous changes characteristic
of reflex sympathetic dystrophy
4) VIRAL INFECTION:
FAVOR: Stimulate osteoclastic resorption and demineralization,
generating stress fractures and pain with weight bearing.
OBJECTION: Theory has not been confirmed by further studies.
5) TRANSIENTISCHEMICEVENTTHEORY:
Produces limited cell death involving only the hematopoietic
and fatty elements.Histology shows intertrabecular edema, inflammatory
infiltrates, fat,boneresorption and new bone formation.
TO of the hip has been proposed as an early reversiblephaseof avascular
osteonecrosis (AVN)

3. Clinical, imaging and histopathologic differences, including the gross
appearance, distribution of repair tissue, and viability of bone trabeculae in
the affected region, have proved they are different disorders.
PATHOPHYSIOLOGYINPREGNANCY:
Pregnancy and lactation are stress factors on maternal calcium homeostasis.
In pregnancy, maternalplacental transfer of calcium and physiological
hypercalciuria
Decreaseserumcalcium
compensated by increasing 1,25(OH)2 D3 levels that enhance gastrointestinal
calcium absorption.
(but overall there is transientdecrease in bone mass during pregnancy).
Transfer of calcium from seruminto breastmilk during lactation
Decreaseserumcalcium
(bone loss in the initial 6 months, and recovering during the 2 years after
lactation).
In pregnantwomen other theories
a. damage to the joint as a result of venous stasis of pregnancy
b. damage to the lumbosacralcord as it passes across thepelvic brim
All these theories do not explain cases seen in men and non
pregnantwomen.

4. CLINICAL FEATURES:
1) Sudden or progressive pain in the affected joint causing limp, without
any previous trauma.
2) Pain increases while walking and standing, often improving with rest.
3) Rapid, severeosteoporosis localized to the same area.
4) ROM of joint restricted and is painfulin the last degrees.
5) Duration of symptoms 6-9 months.
6) Spontaneous involvementof other regions.
Schapira’s threephases:
Initial phase- intense pain with functional impairment, lasting approximately
one month
Middle phase- (one or two months) symptoms remain unchanged and marked
osteopenia appears on x ray
Last phase- spontaneous regression takes place, with improvementin bone
density. This period lasts about four months.
JOINTS INVOLVED:
MOSTCOMMON- Hip, followed by knee, footand ankle.
Transient migratory osteoporosis may presentas single episode
affecting only one joint or recurrentepisodes that may involve two to seven
joints, either successively or with overlapping. The time interval between
recurrences may be shortor as long as two or more years.
IMAGING:
A) RADIOGRAPHY:
i. Bone density is normal until 4-8 weeks have elapsed since the onset of

5. clinical symptoms.
ii. Later on, a periarticular diffuse osteopenia can be seen, that in the hip
rarely affects the pelvic bone and greater trochanter.
iii. Joint space remains normal, which differs from the advanced stages of
AVN.
iv. Bone remineralization takes place spontaneously after a 6-8 month period.
B) RADIONUCLIDEBONE-SCANNING: (High sensitivity, Low specificity)
i. A diffuse and homogeneous increase of radionuclide uptake is seen in the
affected joint a few days after the onset of the symptoms (48 Hours),
even before x ray changes.
ii. When symptoms diminish a gradual decrease in radionuclide uptake is
detected on scintigraphy.
C) MRI:
i. 48 hours after the development of clinical symptoms and regression with
clinical improvement (about6 to 8 months later).
ii. An ill-defined area of decreased signalintensity is seen on T1-weighted
images, with an area of increased signal intensity on T2-weighted images;
these diffusesignal abnormalities havebeen attributed to bone marrow
edema.
iii. In the hip, these changes mainly affect the head, neck and inter
trochanteric region
DIFFERENTIAL DIAGNOSIS:
1) CRYSTAL-INDUCED ARTHROPATHY,
2) RHEUMATOID ARTHRITIS,
3) OSTEOARTHRITIS AND
4) INFECTIOUSARTHRITIS
5) RSD
6) AVN
TREATMENT:
a. Symptomatic treatment with NSAIDS, muscle relaxants, and

6. antianxiety agents.
b. Corticosteroid therapy (15 mg prednisone daily for 4 weeks) followed
by gradual tapering.
c. Physical therapy, range of motion exercises, and forced gradual
weight bearing have been shown to prevent associated localized
muscle atrophy.
d. Weight bearing helps promote cortical thickening giving greater
architectural strength to the bones.
e. Local sympathectomy using posterior tibial nerve blocks have been
helpful in conjunction with the above.
REPEAT MRI EVERY 3 MONTHS TO DETERMINE THE PROGRESSION OF
OSTEOPENIA
TREATMENT OF TRANSIENTMIGRATORYOSTEOPOROSIS INPREGNANCY:
Traumatic fractures of the femoral neck and stress fractures are most serious
complications during pregnancy.
TO during pregnancy has to be treated conservatively with strict
recommendations to restrict weight bearing until there is radiographic evidence
of reconstitution of the bone mass.
A pathological fracturehas to be surgically treated postpartum.