This document summarizes musculoskeletal disorders of the lower extremity, including skeletal and muscle disorders. It describes various joint disorders of the hip, knee, ankle and foot. Specific conditions mentioned include osteoarthritis, avascular necrosis, Legg-Calvé-Perthes disease, slipped capital femoral epiphysis, hip dislocation, labral injuries, and impingement syndromes of the hip. Injuries to various muscle groups like the quadriceps, hamstrings, adductors and plantar fascia are also summarized.

1. Musculoskeletal Diseases of the
Lower Extremity
Remo George, Ph.D., ABSNM, NMTCB(CNMT)

2. Topics
Skeletal Disorders:
• Disorders of the Joints of the Lower Limb
– Osteoarthritis
– Disorders of the Hip Joint
• Avascular Necrosis
• Legg-Calvé-Perthes Disease
• Slipped Capital Femoral Epiphysis
• Hip Dislocation
• Labral Injuries
• Impingement Syndromes
• Disorders of the Knee Joint
– Knee Ligament Injuries
– Meniscal Injuries
– Osteochondral Lesions (Osteochondritis
Dissecans)
– Prepatellar Bursitis
• Disorders of the Ankle and Subtalar Joints
– Sprains
– Osteochondral Lesions of the Ankle
– Miscellaneous Disorders of the Ankle and
Foot
• Morton Interdigital Neuroma, Metatarsalgia,
and Sesamoiditis
• Bone Injuries of the Lower Limb
– Stress Reactions and Stress Fractures
Muscle Disorders:
• Disorders of Muscle-Tendon Groups of the
Lower Limb
– Disorders of the Iliotibial Band, Including
Trochanteric Bursitis
– Disorders of the Hamstring Muscle Group
– Disorders of the Adductor Muscle Group
– Pes Anserine Tendonitis or Bursitis
• Injuries to the Quadriceps Muscle Group
– Patellar Tendinopathy
– Osgood-Schlatter Disease and Sinding-
Larsen-Johansson Disease
– Quadriceps Strain, and Quadriceps and
Patella Tendon Rupture
– Rectus Femoris Avulsion from the Anterior
Inferior Iliac Spine
– Quadriceps Contusions and Myositis
Ossificans
• Injuries to the Anterior Leg Muscle Group
– Tibialis Anterior, Extensor Hallucis Longus,
and Extensor Digitorum Longus
• Injuries to the Posterior Leg Muscle Group
and Associated Soft Tissue Structures
– Gastrocnemius, Soleus, Tibialis Posterior,
Flexor Hallucis Longus, and Flexor Digitorum
Longus
– Sever Disease
– Flexor Hallucis Longus Overload
– Tibialis Posterior Overload or Medial Tibial
Stress Syndrome
• Injuries to the Lateral Leg Muscle Group
– Compartment Syndrome
• Injury to the Plantar Foot Muscles and
Plantar Fascia
– Plantar Fasciitis

3. Disorders of the Iliotibial Band:
Including Trochanteric Bursitis
• Symptoms: Pain on rising
up from sitting, pain to lie
on
• Bursa irritated between
femoral trochanter and
gluteus medius/iliotibial
tract
• Trauma/hip Sx/ repetitive
movement/spontaneous
• Tenderness over gt.
Trochanter
• Female:Male= 4:1.
Incidence 2/1000
• Tx: injection/NSAID/PT
Focal increased uptake of
99mTc-MDP in left greater
trochanteric region compatible
with bursitis (arrow)

4. Disorders of the Hamstring
Muscle Group
• Muscle overload
– challenged with a sudden
load
– stretched beyond it’s limit
• Muscle gets stretched too
far
• Seen in running sports:
– football, basket ball,
soccer, runners, dancers,
young athletes still growing
• Signs/symptoms: swelling,
tenderness, bruising/
discoloration
• Ischial avulsion injury
possible Ischial avulsion fracture (arrow). A 17-year-old
female cheerleader who had sudden onset of
buttock pain with a high-kicking maneuver.

5. Disorders of the
Adductor Muscle Group
• Groin strain:
– from acute or repetitive
overload
– sudden twinge or tearing
– pain, weakness, and internal
hemorrhaging
• Usually adductor longus
injury
• Avulsion fractures of inferior
pubic ramus possible
• Causes: running, jumping,
twisting with hip external
rotation, over-stretching/too
forceful contraction
• Tx: RICE (rest, ice,
compression, elevation)
therapy, NSAIDs MRI of the thighs, showing a tear of the left
adductor muscle group in a hockey player.
99mTc-MDP muscle uptake. Significant
injury due to weight lifting damage in
adductor muscle groups of medial thighs
(arrow). Biochemical evidence of elevated
muscle enzymes was also present.

6. Combined Muscle Group Injury
Pes Anserine Tendonitis or Bursitis
• Anteromedial knee pain,
occasional swelling
• Acute inflammation of:
– one or more of three
conjoined tendons near
their insertion
(tendonitis)
– Bursa lying 2 inches
below the medial knee
joint (bursitis)
• Causes: overuse/ friction
(from valgus, flatfoot,
rotatory stresses, direct
contusion)
• Tx: Ice, NSAIDS, steroid
inj.
NM imaging of blood-
pool showing
hyperemia of synovial
lining (pes anserine
bursitis) and bony
lateral tibial plateau.
Arrow points to
bursitis. (B) MRI shows
large joint effusion and
anserine bursitis
(arrow) in same medial
area of knee as in A.
J. Nucl. Med. Technol. June 2007 vol. 35 no. 2 64-76

7. Injuries to the Quadriceps Muscle Group
Patellar Tendinopathy (Jumper’s knee)
• Pain usually at the
inferior pole of patella
• Patellar tendon
overload from
repetitive knee flexion
and extension
• At risk: basketball
players, volleyball
players, bicyclists,
rowers, mogul skiers,
baseball catches,
supermarket shelf
stockers, carpenters,
and carpet layers.
• Tx: RICE, NSAIDs, Rehab
MRI showing patellar tendonitis. The pale
area indicates inflammation and swelling.
Chronic patella
tendinitis. Triathlete
with long history of
recurrent pain in the
proximal left tibia in
spite of multiple
corticosteroid
injections. The
SPECT/CT images
demonstrate schlerosis
of the tibial tubercle
and calcification of the
adjacent patella
tendon in the CT
images (arrowheads)
with intense uptake at
both sites.

8. Injuries to the Quadriceps Muscle Group
Osgood-Schlatter Disease (OSD)/
Sinding-Larsen-Johansson Disease (SLJD)
• More common in
older children/ young
adults
• Repetitive overload
at the patella tendon
insertion at the tibial
tuberosity (OSD), or
at the origin of the
patella tendon at the
inferior pole of the
patella (SLJD)
• Significant pain,
tenderness,
inflammation, or
partial avulsions of
the tibial tuberosity
(in OSD)
J Nuc Med 28:1768-1770,1
a: Normal lateral 99mTc-MDP blood-pool image of right
knee, b: Lateral blood-pool image of the left knee with
abnormalities (arrows) corresponding to the inferior
patellar border and tibial tuberosity (left knee).

9. Injuries to the Quadriceps Muscle Group
Quadriceps Strain, and Quadriceps & Patella Tendon Rupture
• Injury following
forceful quadriceps
contraction with
foot planted
• “unstable knee”
• Anterior knee
swelling
• Unable to extend
knee
– Patella will move
up for PTR, but
will not move for
QTR
• Palpable defect
proximal or distal to
patella
• Tx: knee
immobilizer,
crutches, and Sx MRI showing Normal (L); Quadriceps tendon rupture (R)
Lateral radiograph of the
knee, showing an abnormally
highriding patella after an
acute patella tendon rupture.
The patient was a 40-yearold
airline pilot who described
“landing a little aft of center”
while alpine skiing. A sudden
forceful quadriceps
contraction while attempting
to regain balance resulted in
this injury.

10. Injuries to the Quadriceps Muscle Group
Rectus Femoris Avulsion from the Anterior Inferior Iliac Spine
• Pain at front of the hip
• occur most often in
young
• Possible from forceful
contraction of rectus
femoris
• RICE, NSAIDs, Rehab, Sx
(if > 3cm separation)
http://gamma.wustl.edu/bs137te144.html

11. Injuries to the Quadriceps Muscle Group
Quadriceps Contusions and Myositis Ossificans
• From direct & forceful
trauma to front of thigh
• Ant. thigh pain, stiffness,
tenderness, ecchymosis,
swelling, antalgic gait
• Intramuscular hematoma
 calcific transformation
myositis ossificans
(quads – most common
site)
A bone scintigram (A) shows marked accumulation of
radiotracer in the region of Rt. Hip. Plain radiograph
(B) of Rt. Hip shows ossification in soft tissues.

12. Injuries to the Anterior Leg Muscle Group
Tibialis Anterior, Extensor Hallucis Longus, and
Extensor Digitorum Longus
• Overload injuries less
common
• Overload of tibialis
anterior – eg. down hill
running
– Pain in muscle belly, or
musculotendinous
junction, or
anteromedial midfoot
tendon insertion site
This 57 year-old male experienced
spontaneous pain in medial side of left foot.
SPECT/CT helped enable a diagnosis of
tibialis anterior tendinosis and enthesopathy
and also calcaneocuboidal artrosis.

13. Injuries to the Posterior Leg Muscle Group and
Associated Soft Tissue Structures
Achilles Tendon Issues
• Achilles tendon (AT) overload is
common
• Chronic: swollen, nodular, &
tender AT (tendinitis), with
collagen breakdown &
microscopic tearing (tendinosis)
• Acute: sudden, powerful
eccentric force (eg. basketball) 
rupture of AT (audiable pop)
• RICE, Sx if needed, rehab Bilateral Achilles
tendinopathy.
Intense uptake
around the Achilles
tendons with
associated bursitis
(arrowheads)

14. Injuries to the Posterior Leg Muscle Group and Associated Soft Tissue Structures
Sever Disease
• Traction apophysitis of
Achilles tendon insertion
on posterior calcaneus
• Seen in active adolescents
during rapid growth (bones
lengthen, muscles tight)
• Exacerbated with activities
and improved with rest
• Calcaneal pain, tight
gastrocnemius-soleus
• Tx: ice, rest, brace, rehab

15. Injuries to the Posterior Leg Muscle Group and Associated Soft Tissue Structures
Shin Splints
(Anterior/ Medial Tibial Stress Syndrome)
• Common in runners,
dancers and military
recruits
• overload dysfunction of:
– tibialis anterior, extensor
digitorum longus and
extensor hallucis longus
(anterolateral shin splint)
– tibialis posterior, medial
gastrocnemius, or medial
soleus (posteromedial shin
splint)
• Bone overload persistant
stress  periostitis  tibial
stress fracture

16. Injuries to the Lateral Leg Muscle Group
Compartment Syndrome
• Pressure within a
muscle compartment
(95% cases in
lateral/ant) is
abnormally elevated
causing ischemia
• Causes:
– Acute: trauma (eg.
fracture, crush injury);
can cause permanent
muscle damage;
surgical emergency
– Chronic: occurs in
runners, military
recruits; lower limb
affected;
pathophysiology
poorly understood
(↑muscle relaxation
pressure  ischemia);
Tx with NSAIDs, Rest
99mTc-MDP bone imaging showing compartmental syndrome in a
patient following lithotomy position for 6 hours. Urine bag &
catheter (closed arrows)
Clinical Nuclear Medicine Vol 38, Number 5, May 2013
Rhabdomyolysis Associated
with Compartment Syndrome

17. Injury to the Plantar Foot Muscles and
Plantar Fascia; Plantar Fasciitis
• A.k.a plantar heel pain
syndrome
• Painful inflammatory
process of plantar
fascia; pain in volar
heel, esp. 1st few
steps in morning
• Overload injury due to
biomechanical issues
(ankle lean inward,
flat foot), repetitive
trauma (15-20%
runners affected)

18. Skeletal Disorders

19. Osteoarthritis
• Etiology/Risk
Factors: Age,
Trauma, Genes
• Pathogenesis:
Progressive
EROSION of
articular cartilage
• Morphology: X-
Ray, “eburnation”,
“joint mice”,
osteophytes
• Clinical
Expression: PAIN,
Limitation of
motion
Heberden’s Nodes in DIP

20. Osteoarthritis
Nature:BoneKEy Reports, 2012, (1)136

21. • Cause: ISCHEMIA
– Trauma
– Steroids
– Thrombus/Embolism
– Alcohol abuse
– Vessel injury, e.g., radiation
– Sickle cell anemia
– INCREASED intra-osseous
pressure vascular
compression
– Venous hypertension
Disorders of the Hip Joint
Avascular Necrosis

22. Disorders of the Hip Joint
Legg-Calvé-Perthes Disease
• Idiopathic osteonecrosis of femoral head
• Occurs in children, typically boys 4-10yr
• Bilateral 10%
• Prognosis better if onset < 6yrs, ↑rates
of hip dysfunction into early adulthood if
older
• Wait-and-watch, braces, Sx (osteotomy),
rehab
Legg-Calvé-Perthes disease. A,
(top row) Scintigrams by
standard parallel-hole collimator
fail to reveal the abnormality.
Pinhole images of the same
patient (bottom row) reveal the
characteristic lentiform area of
decreased uptake on the left. B,
Corresponding radiograph
obtained months later reveals
deformity of the left femoral
epiphysis with flattening,
increased density and increased
distance between the epiphysis
and the acetabulum.

23. Disorders of the Hip Joint
Slipped Capital Femoral Epiphysis
• Displacement of capital
femoral epiphysis from
metaphysis (20 to disruption of
physis in the immature hip
• Cause: acute trauma/
repetitive microtrauma, obesity
• Most common hip disorder in
adolescent (8-15y), boys > girls
Pediatric Nuclear Medicine edited by S.T. Treves; P262

24. Disorders of the Hip Joint
Hip Dislocation
• Requires significant trauma
• Dislocation > fractures in
children
• Posterior dislocation
(presents with hip flexion,
internal rotation and
adduction) > anterior
dislocation (hip extension,
external rotation, abduction,
& acetabular fx)
• Needs closed reduction
under anesthesia, or Sx
• Concern for sciatic nerve
injury, osteoarthritis, AVN in
10% pts.

25. • Injury from acute or
repetitive trauma,
hypermobility,
dysplasia
• Groin pain, clicking of
hip
• MRI arthrography with
intraarticular contrast
is best imaging for Dx
• Tx: PT, NSAIDs, rest,
intraarticular steroid
shot, arthroscopic
debridement/repair
Disorders of the Hip Joint
Labral Injuries
Examples of labral
tears. (A) “Eyebrow”
pattern of uptake
corresponding to an
anterosuperior labral
tear (arrowhead). There
is also a femoral head
osteochondral fracture
(arrow) in association
with the steep
acetabular angle of hip
dysplasia. (B)
“Eyebrow” pattern of
uptake of an
anterosuperior labral
tear. (C) Focal uptake in
a tear of the superior
labrum.Clinical Nuclear Medicine • Volume 29, Number 8, August 2004

26. • Morphological
variations of
acetabulum/femora
l head resulting in
mechanical damage
to joint
• Groin pain, limited
ROM, DJD
• 2 types:
– CAM: bump @
femoral head-neck
jn.
– Pincer: acetabular
over-coverage of
femur head
• Tx: PT, NSAIDs, Sx
Disorders of the Hip Joint
Impingement Syndromes
Hip impingement. Increasing
right hip pain in a motocross bike
rider which worsened after a
number of falls. Hyperemia
(arrowhead in BP) and intense
uptake around the right hip
(arrowhead in delay) with the
SPECT/CT image showing the site
of impingement between the
anterior-superior acetabulum and
lateral femoral head (arrowheads)

27. Disorders of the Knee Joint
Knee Ligament Injuries
• MCL & ACL injuries - most
common
• MCL: valgus sprain  medial
pain, swelling but no joint
effusion
– Tx: ice, elevation, knee
immobilizer, rehad
• ACL: most functional
impairment in sprains;
twisting knee injury; “pop”
sound; joint effusion possible;
Segond fx (lat. tibial plateau
avulsion)
– Tx: ice, elevation,
compression, knee brace,
rehab
• PCL: Less common, seen in
soccer, dashboard injuries
Segond fx
Anterior bone scintigraphy demonstrates a large intense lesion
in the left lateral tibial plateau which was confirmed on MRI.
The less intense lesion in the lateral femoral condyle was not
seen on MRI. The faint but definite focal uptake peripherally in
the medial femoral condyle (arrow head) was an avulsion of
the insertion of the medial collateral ligament on MRI and
confirmed at surgery. The classic triad of avulsion of the
medial collateral ligament with opposite “kissing” lesions
laterally is obvious on scintigraphy. Knowledge of this type of
injury facilitates scintigraphic diagnosis, however, avulsion
injuries could be misreported as fractures.

28. Disorders of the Knee Joint
Meniscal Injuries
• Common; can be acute
or chronic
• Acute tear: from
sudden twisting
motion
• Symptoms: pain,
swelling, clicking;
• Bucket handle tear 
flipped up into
intercondylar notch 
locked knee
• Tx: ice, elevation,
NSAIDs, brace
Medial meniscus tear. This was a surgically
proven injury in a patient being assessed for
patella tendinitis. The SPECT/CT study shows a
region of intense uptake and sclerosis in the
mid-body of the crescent of the medial meniscal
subchondral bone (arrowheads) in keeping with
a tear of the meniscus and adverse remodeling
of the underlying tissues.

29. Disorders of the Knee Joint
Osteochondritis Dissecans
• Mostly in 10-15yr olds
• Lesion in subchondral bone (lat. aspect
of medial femoral condyle) 
progresses through stages to overlying
articular cartilage  Grade 4 complete
avulsion of osteochondral fragment &
dislocation
• Mechanism unknown, causative factors
may be genetic/ vascular/ trauma
• Symptoms: recurrent pain & swelling
(worse with stress, better with rest)
• Tx: Rest, Sx
A B

30. Disorders of the Knee Joint
Prepatellar Bursitis
• A.k.a “carpet layer's
knee”/ “nun’s knee”
• Associated with
kneeling for extended
time
• Swelling & pain
anterior to patella
• Tx: RICE therapy to 
swelling & pain,
aspiration & steroid
inj., Sx (rare)

31. Disorders of the Ankle and Subtalar Joints
Sprains
• Most common MSK injury of leg (25% of
all sports injuries); predisposing factor:
previous sprain
• Inversion/lateral ankle sprain of ant.
talofibular ligament (weakest, most
common), eversion (deltoid,
uncommon), Syndesmotic high-ankle
sprain (uncommon, severe)
• Small (Gr-I) to partial (Gr-II) to full tear
(Gr-III)
• Diffuse pain, swelling, hematoma
discoloration possible
• Tx: RICE, brace, rehab
Partial
avulsion
fracture
after sprain
Am J Nucl Med Mol Imaging 2015;5(4):305-316

32. Disorders of the Ankle and Subtalar Joints
Osteochondral Lesions of Ankle
• Causes: sprains, trauma
• Deep ankle pain, worse
with activity, better with
rest
• Can affect medial talus
(usually from inversion, less
severe, heals
spontaneously) or lateral
talus (forced eversion,
more severe, difficult to
self-heal)
• Rehab, Sx if severe
osteochondral lesion
(arrow) in the inferior
posterior talus
J Nuc Med 32:2241-2244
(OCTDF = osteochondral
talar dome fractures)

33. Disorders of the Ankle and Foot
Morton Interdigital Neuroma, Metatarsalgia, and Sesamoiditis
• Similar presentations (Diff. Dx challenging)
• Morton’s neuroma: irritation of an interdigital foot
nerve (b/w 3rd & 4th metatarsal head most common)
leading to pain (“pebble in shoes”), worse with
metatarsal (MT) head, interdigital nerve loading (eg.
high heels)
• Metatarsalgia: Pain coming from metatarsal heads
(instead from b/w heads), 2nd head pain most common,
from overload of MT heads (running, toe walking, high
heels)
• Sesamoiditis: Pain in 1st MT head following sesamoid
bone injury
• Bone scans, MRI helful for Dx
• Tx: Unloading of forefoot (large toe box shoe, avoid
high heels, gel insoles for wt. distribution
Am J Nucl Med Mol Imaging 2015;5(4):305-316

34. Stress Reactions and Stress Fractures
• Repetitive overload injury to bone
• Stress response ( bone
remodeling)  stress reaction
(maladaptive areas w/ resorption >
deposition)  stress Fx (hairline
break)
• Causes: Female athlete triad
(disordered eating, amenorrhea,
osteopenia), pes cavus, pes planus,
leg length discrepancy, Q-angle,
improper shoe fit/ cushion
• Tx: ice, rest, NSAIDs, image non-
healing > 6 wk (bone scans very
sensitive, MRI good for grading)
• Prevention: strengthen muscles
( strain on bone)