PELVIC
OBLIQUITY
Mohahad osman, MD
Assist. prof. Zagazig University
Definition of Pelvic Obliquity ( PO)
A- PO is failure of the pelvis to lie in a perfectly
horizontal position in the frontal plane; ie;
interspinous line is not perpendicular to midline of
body provided that legs are parallel to midline of
body.
B- 3-D definition : any fixed malalignment bet.
Spine & pelvis, in frontal, sagittal, horizontal or all
these 3 planes.
CLASSIFICATIONS of PO.
I- Mayer (1936) :
1- Functional / non-structural PO :
- present only when pt. stands with knees straight & no lift
under foot & disappear on sitting & on recumbency w legs
parallel to midline of body
- due to LLD.
2- Structural / fixed PO :
-persists in all positions & cannot be passively corrected.
-Aetiology:
a- infrapelvic (hips)
c-suprapelvic ( spine)
b- pelvic
d- combined
Classifications of PO. ( cont.)
II- Dubousset ( 1991) :
1- Regular PO : spine & pelvis in
same directions of deformity.
2- Opposite PO : in opposite
directions.
INFRA-PELVIC FIXED PO.
A- Congenital hip contracture:
1- cong. Abductor contracture
2- cong. Adduction contracture
B- neuromuscular hip contractures :
abd, add or both.
SUPRA-PELVIC FIXED PO.:
- in cong. or neuromuscular scoliosis
- not in idiopathic scoliosis ( curve not
extend to pelvis )
DISABILITY & SEQUILAE of PO.
A- locomotor:
Interferes w sitting, standing balance & walking.
B- 2ry. Deformities :
* spinal : L. scoliosis( cause / result) . Increased L.
lordosis.
* hip : Abd / add contractures .
* knee : hyperextension on long side
* apparent LLD.
C- decubitus ulceration: ischial / G. trochanter on
lower side.
DIAGNOSIS & ASSESSMENT OF PO.
HISTORY
GENERAL EXAM.:
* CARDIOPULMONARY FUNCTION
* Gait :
- short leg limp ( dipping gait)
- Trendlenburg gait
EXAM OF DEFORMITY :
* inspection
* palpation
EXAM for FIXED DEFORMITY:
a- Pelvic obliquity:
* Oblique pelvis : interspinous line is not perpendicular to
midline of body provided that legs are parallel to midline of body
* functional PO.; present only when pt. stands with
knees straight & no lift under foot & disappear on sitting & on
recumbency w legs parallel to midline of body
* fixed PO. : persists in all positions & cannot be passively
corrected
1- infra-pelvic; overcomed by swining legs to one side or
other while recumbent.
2- supra-pelvic; never.
EXAM for FIXED DEFORMITY ( cont):
B- Scoliosis:
* trunk alignment : plumb line
* type of curve
* flexibility / rigidity of curve
* rotation
* neurologic exam.
* clinical photographs.
C- Fixed hip def. :
abd, add, flexion ,rotation
ROM : hip. Spine . Knee. Ankle.
NEUROLOGIC EXAM:
- Power
sensation
- specific muscles ( hip / trunk)
MEASUREMENTS :
- PO.
- LLD ( app / true)
- circumference.
SPECIAL TESTS :
- iliotibial band
- hip instability.
-
Ober test
RADIOLOGIC ASSESSMENT
A- Pelvic obliquity :
* diagnosis of PO. :
- in frontal plane
- 3-D
* Angle of PO: Osebold , 1982
B- Scoliosis:
A- Angle ( Cobb )
B- rotation ( pedicles displac.)
C- c rigidity : - side bending - traction
D- Torso decompensation: Osebold
E- Pt. maturation : Risser sign
LORDOSIS
SPINA BIFIDA
2ry changes in hips
CT
MRI
- suspension
A- side-bending XR
B- suspension XR
A
B
C- traction XR
C
Torso
decompensation /
trunk list
C- MEASUREMENT of LEG LENGTH
-Plain X- ray: scanogram
- CT
OTHER INVESTIGATIONS:
* cardiopulmonary
* Biochemical ; ms dystrophy
TREATMENT
TTT of PO is directed to the specific cause
Ttt of functional PO:
- by leg length balancing
- up to 3 cm LLD ; shoe lift
- > 20 cm LLD; orthosis
- 3-20 cm LLD; shortening, lengthening or both.
* correct bony def. or jt. Contracture 1st.
TTT of infra-pelvic type:
A- cong hip contractures:
- early ; stretching / traction and spica casting
- neglected ; surgical release & splinting.
B- Paralytic hip contractures ; surgical
- abd contracture by ;
1- soft tissue release ( prox & distal).
2- STR+ erector spinae transplant or
3- STR+ intertroch. femoral osteotomy ; > 3 y old,
severe, 3-D
- add contracture ;
TTT of supra-pelvic type
A- Abdominal fascial plastic operations
B- Muscle- tendon transplant operations
C- Spinal surgery.
Spinal surgery :
Objective: correction of def. to the point at which pelvis is
level & then fusion of spine & pelvis in that corrected position.
Methods :
A- Post. Surgery only; if pelvis can be levelled by passive
bending / traction
* Harrington sacral bar * Luque * recent segmental
instrumentations
B- Combined ant. & post . Surgery ; if pelvis can not be
levelled by passive bending / traction or deficient post. elements
* ant correction& fusion without instrumentation
* ant correction& fusion with instrumentation ( Dwyer
system).
TTT of combined type
A- correct hip & knee def. 1st then spinal
fusion, otherwise spinal def will recur [ Barr,
1950 & Turek, 1984]
B- Beaty [1992]; when PO is moderate & L.
scoliosis is fixed , correct scoliosis w
instrumentation 1st.
TTT of PO that cannot be corrected by
hip / spinal surgery
INDIC.:
1- 2ry osseous hip changes or 2ry arthritic changes in L spine
rendering full correction impossible.
2- residual significant fixed PO [ 18 deg]
METHODS:
1- LL realigning to trunk by femoral osteotomy
2- post iliac osteotomy [ Lindseth,1978]; compensating
pelvic def. placing isch tuberosities & acetabla in planes
perpendicular to long axis of body
3- ischium excision; partial / complete
post iliac osteotomy [ Lindseth,1978];