This document provides an overview of hemiarthroplasty, which involves replacing the femoral head with a prosthesis while retaining the natural acetabulum. It discusses the history and types of prostheses used in hemiarthroplasty. The indications, surgical procedure, postoperative care, and possible complications of hemiarthroplasty are described. A case example of a 78-year-old female undergoing cemented bipolar hemiarthroplasty for a fractured neck of femur is presented.
2. Overview
INTRODUCTION
HISTORY
INDICATIONS OF HEMIARTHROPLASTY
TYPES OF PROSTHESIS
STEM PROSTHESIS
MEDULLARY PROSTHESIS
BONE CEMENT
BASIC TERMS
PREOPERATIVE PLANNING
TEMPLATING
VARIOUS APPROACHES
CASE DISCUSSION
EXAMINATION
PRE OP XRAY
APPROACH USED
POST OP XRAY
POSSIBLE COMPLICATIONS
POST OP REHABILITATION
3. INTRODUCTION
HEMIARTHROPLASTY MEANS REPLACEMENT OF HALF JOINT.
It involves replacement of femoral head with prosthesis while retaining the natural
acetabulum (endoprosthesis)
4. HISTORY
Prosthesis replacement was introduced in 1932 by Grooves by replacement of
femoral head with IVORY
In 1938 smith person first used Vitallium mould arthroplasty for hip in case of
ankylosis.
In 1947 bipolar prosthesis first introduced by james E. bateman and gilbert
In 1983 Charnley –Hastings used bipolar prosthesis
5. INDICATIONS
Fracture neck of femur is the commonest cause in old age individual
Inflammatory arthritis
Rheumatoid
Juvenile idiopathic
Ankylosing spondylitis
Osteoarthritis (degenerative joint disease, hypotrophic arthritis) Primary Secondary
Developmental dysplasia of hip
Coxa plana (Legg-Calvé-Perthes disease)
Posttraumatic Slipped capital femoral epiphysis
Paget disease
Osteonecrosis
7. STEM PROSTHESIS
It has head and a stem
Stem is inserted into the neck and anchored in the cortex of the shaft
Not used nowdays
Eg : JUDGET BROTHERS
8. MEDULLARY PROSTHESIS
It has a head and stem
Anchored in medullary canal
It Is either fixed by Press fit or by bone cement
Austin moore 1957 devised intramedullary self locking prosthesis with fenestration
to facilitate bone growth and to increase blood supply
9. UNIPOLAR PROSTHESIS
HEAD : It range from size 39mm to 59mm
Neck
Stem : triangular in shape , thin and become easy for insertion but chances of breakage
of tip is there
Collar
Fenestrations : it help in increasing bone growth in between prosthesis to allow better
fixation and increase vascular growth
10. Types of unipolar prosthesis
1. Austin moore prosthesis
2. Thompsons prosthesis
11. BIPOLAR PROSTHESIS
Gilberty and baetman in 1974 used bipolar prosthesis.
Erosion and protrusion of acetabulum would be less because
of motion present between metal head and inner bearing
Motion between metallic cup and acetabulum as cup is not
fixed
12. Bipolar designs provide greater overall range of motion than unipolar designs or
convential THR
It is done with head size ranging from 22mm or 32mm diameter
13. ADVANTAGES
1. WIDE RANGE OF MOTION
2. BETTER STABILITY
3. INCREASED LIFE SPAN OF PROSTHESIS
4. CAN CONVERT INTO TOTAL HIP ARTHROPLASTY LATER
5. LESS WEAR AND TEAR OF THE THE FEMORAL HEAD DUE TO LESS FRICTION
14. WIDE RANGE OF MOTION
Due to size and geometry of inner bearing
After certain arc of abduction-adduction movements and then further movement
take place between acetabulium and outer metallic cup prosthesis
15. Better stability
At the degree of movement of the inner bearing , joint tends to dislocate which is
prevented by movement of outer bearing that too in opposite direction
16. UNIPOLAR VS BIPOLAR PROSTHESIS
UNIPOLAR
LOWER COST
SIMPLE TO PERFORM
BIPOLAR
LESS WEAR
MORE MODULAR
MORE EXPENSIVE
CAN CONVERT INTO THR
17. CEMENTED VS PRESS FIT STEM
CE MENTED STEM
Acrylic cement is now standard for
femoral stem fixation.
Improved mobility , function and
walking aids less chance of peri-
prosthetic fracture.
Sudden intra-op cardiac death risk
slightly increased due to addition of
additional cement material
(methamethacrylate embolism
chances is higher )
NON CEMENTED
(PRESS-FIT)
2 pre-requsite
1. Immediate mechanical stability at the time of
surgery
2. Good contact between implant surface and
the viable host bone.
Complain of pain is common
Implant selection should be more precise
Chances of loosening of stem is higher
Intra-operative fracture of shaft of femur is
more
18. BONE CEMENT
POLYMETHYLACRYLATE remains one of the most enduring materials in
orthopaedic surgery.
In ARTHROPLASTY :
1. bone cement allows swcure fixation of implant to bone
2. It’s not a glue , it act as grout (fixation is achieved with ingrediants not with
adhesion)
3. It act as mechanical interlock and space filling
20. PHASES OF BONE CEMENT
DIFFERENT PHASES OF BONE CEMENT ARE :
1 . MIXING PHASE : (UPTO 1 MIN)
Wetting and polymerization ; cement relatively liquid ; very moveable ; at the end mixture is
homogenous sticky mass.
2. WAITING PHASE : (VARIABLE UPTO SEVERAL MINUTES )
Chain propogation ; cement less liquid ; more chains ; less movable ; cement is neither sticky
nor tough.
3. WORKING PHASE : ( 2-4 months )
chain propogation ; less movability ; increase in viscosity
4. SETTING PHASE :
Chain growth finished ; no movability ; harden cement ; temperature gradually settles and
undergoes volumetric shrinkage.
21.
22. Basic terms
1. Vertical height (vertical offset )
2. Medial offset (horizontal offset)
3. Version of the femoral neck (anterior offset)
4. Jump distance
23. VERTICAL HEIGHT (VERTICAL OFFSET) :
It is determined primarily with the base length of
prosthetic neck + length gained by modular head
used
MEDIAL OFFSET (HORIZONTAL OFFSET ) :
Distance from the center of femoral head to a line
throught the axsis of the distal part of the stem.
It help in deciding moment of arm of the abducter
musculature and joint reaction force.bone
impingment
24. VERSION (ANTERIOR OFFSET)
Refers to the orientation of neck in reference to
the coronal plane
(ante-version/retro-version)
Important to attain stability of the joint
Normally has 10-15 degree of ante-version of
the femoral neck in relation to the coronal
plane.
25. Size of femoral head , ratio of femur head and neck diameter and
shape of neck of femur impart great effect
On RANGE IF MOTION
JUMP DISTANCE :
It is the distance head must travel to escape rim of the socket (which
is approx. ½ diameter of the head of femur )
IDEAL CONFIGRATION OF femur head :
1. Trapezoidal neck
2. Large diameter allow greater range of motion
3. Non skirted head
26. PREOPERATIVE PLANNING
RADIOGRAPHIC EXAMINATION:
1. X RAY of pelvis with both hip AP view
2. X-RAY of involves hip with thigh in AP and LAT view
General status of the patient include status of knee , spine .
Blood parameters required to know current and post-operative parameters.
History of any other drug intake leading to large amount of blood loss
Limb length disperancy or any other deformity
27. TEMPLATING
Pre-operative templating is used
to determine the appropriate
femoral stem and unipolar and
bipolar head size.
In this normal hip is used as a
template to duplicate normal leg
and hip offset.
Proper hip offset help to maintain
proper soft tissue tension
28. Templating aids in :
1. Selecting type of implant to restore center of rotation of hip
2. Best femoral fit
3. Tell us about the level of bone resection
4. Neck length to restore equal limb length and femoral offset
29. TEMPLATING
Position the hips in 15 degrees of internal
rotation to delineate better femoral geometry
and offset. Femoral offset will be underestimated
when the hips are positioned in external rotation.
standard pelvic radiograph, magnification is
approximately 20%.
Draw a line at the level of and parallel to the
ischial tuberosities that intersects the lesser
trochanter on each side and compare the two
points of intersection and measure the difference
to determine the amount of limb shortening.
30. the acetabular overlay templates on the film and
select the size that matches the contour of the
patient’s acetabulum without excessive removal of
subchondral bone. The medial position of the
acetabular template is at the teardrop and the
inferior margin at the level of the obturator foramen.
Mark the center of the acetabular component on the
radiograph; this corresponds to the new center of
rotation of the hip.
Place the femoral overlay templates on the film and
select the size that most precisely matches the
contour of the proximal canal and fills it most
completely . Make allowance for the thickness of the
desired cement mantle.
31. Select the appropriate neck length to restore
limb length and femoral offset. If no shortening is
present, match the center of the head with the
previously marked center of the acetabulum. If a
discrepancy exists, the distance between the
femoral head center and the acetabular center
should be equal to the previously measured limb
length discrepancy .
When the neck length has been selected, mark
the level of anticipated neck resection and
measure its distance from the top of the lesser
trochanter to use as a reference intraoperatively.
Template the femur on the lateral view in a
similar manner to ascertain whether the implant
determined on the AP film can be inserted
without excessive bone removaL
32. VARIOUS APPROACH TO HIP
ARTHROPLASTY
POSTERIOR APPROACHES :
1. Gibsons approach (postero-lateral approach)
2. Southern or mores approach
LATERAL APPROACHES :
1. watson jones approach (antero-lateral approach)
2. harris lateral approach
3. modified hardinge approach (transgluteal approach)
33. CASE :
NAME : RAWEL KAUR
AGE : 78 YEAR SEX : FEMALE
PRESENTED TO THE OPD WITH A/H/O SLIP AND FALL 8 DAYS AGO WITH
COMPLAIN OF :
1. pain and swelling in left hip region.
2. Inability to bear weight on left lower limb.
34. On examination :
Inspection :
ATTITUDE : left lower limb flexed abducted and externally rotated as
compare to right lower limb.
1. Overlying skin intact .
2. Apparent shortening of left lower limb present as compare to right lower limb
3. No fullness present over scarpa’s triangle.
4. GT could not be seen on inspection.
5. No appreciable wasting present over left thigh or calf muscle.
35. PALPATION :
1. local temprature not raised as compare to the right side.
2. Direct tenderness, indirect tenderness and thurst tenderness present over left lower
limb
3. GT is higher up on left side as compare to right side
4. Loss of transmitted movement absent and could not be examined properly due to
pain.
RANGE OF MOTION :
Limited movement at left hip joint with active ankle dorsiflexion present at
left ankle
DNVS :
Distal pulses palpable with no sensory loss.
36. MEASUREMENT :
RIGHT LEFT
APPARENT LENGTH 101 CM 99 CM
TRUE LENGTH 77 CM 75 CM
SUPRATROCHANTRIC
LENGTH
4 CM 2 CM
THIGH 42 CM 41 CM
CALF 36 CM 36 CM
37. DIAGNOSIS
1 week old fracture neck of femur left side
Classification:
AO classification
1. Femur labelled as no 3
2. Neck fracture labelled as 31B
3. Subcapital labelled as 31B1
Garden classification type IV
39. MANGEMENT DONE WITH :
CEMENTED MODULAR BIPOLAR HEMIREPLACEMENT
ARTHROPLASTY
USING MODIFIED HARDINGE APPROACH
(DIRECT LATERAL TRANSGLUTEAL APPROACH)
40. HARDINGE DIRECT TRANSGLUTEAL APPROACH
Make patient lie in lateral position on operating
table.
Make a posteriorly directed lazy-J incision
centered over the greater trochanter .
Divide the fascia lata in line with the skin
incision and centered over the greater
trochanter. & Retract the tensor fasciae latae
anteriorly and the gluteus maximus posteriorly,
exposing the origin of the vastus lateralis and
the insertion of the gluteus medius
Incise the tendon of the gluteus medius
obliquely across the greater trochanter, leaving
the posterior half still attached to the trochanter.
Carry the incision proximally in line with the
fibers of the gluteus medius at the junction of
the middle and posterior thirds of the muscle
41. Elevate the tendinous insertions of the anterior
portions of the gluteus minimus and vastus lateralis
muscles. Abduction of the thigh exposes the
anterior capsule of the hip joint & Incise the capsule
as desired.
Neck osteotomised using an oscillating saw 1 cm
proximal to the lesser trochanter
(excessive neck resection can lead to shortening of
lower limb and short femoral neck component can lead
to prosthetic dislocation due to soft tissue laxity
Lengthning of neck lead to increase pressure on the
acetabular cartilage leading to erosion.)
Head is removed with the help of cork-screw by
incising the ligament teres.
42. Femoral head size should be measured using a caliper or head
template.
1. Smaller diameter head will result into assymetrical load in
acetabulum leading to protusio acetabuli
2. Head of larger diameter will not fully seated in the acetabulum
leads to the risk of dislocation
Box osteotome is used to open the femoral canal
Sequential reaming is done with rasp until appropriate size of
stem
Trial stem is placed to confirm the size of stem
Cementing is done through retrograde fashion using a cement
gun or manual pressurization technique.
43. Prosthesis is inserted using manual force and light taps.
Excessive cement is removed.
Trial femoral head and neck is placed and hip is then reduced using
traction and external rotation
Hip stability is checked through :
1. External rotation with hip in full extension
2. Flexion and adduction
3. Telescopic test
44. Trial stem is then replaced with appropriate prosthesis
Head is again reduced
Stability is reassessed
Short external rotators and underlying capsule are repaired.
Closure done in layers.
Shift the patient in abduction by keeping a pillow between legs
46. Post op comment
GRUEN DIVIDED FEMORAL COMPONENT INTO 7 ZONES :
to look for cement around the femoral prosthesis.
The thickness in cement mantle should not drop below 2mm at anyplace
i.e SHOULD NOT ALLOW METAL-BONE CONTACT
POST OP CRITERIA for quality of cementing is divided into 4 criteria :
A. Complete filling of medullary cavity by bone cement
B. Slight radiolucency at bone cement interface
C. Radiolucency involving 50-99 % of bone –cement
interface(incomplete cement mantle
D. Failure to fill the canal with cement (tip not covered)
47. COMPLICATIONS :
1. erosion of acetabulum
2. fracture of stem of prosthesis
3. dislocation of prosthesis
4. fracture of shaft of femur
5. Retroversion and anteversion of prosthesis
6. Neck length variation
7. Sciatic nerve injury
48. Post operative management
Knee ROM exercises and quad strengthening exercises on 1st post op day.
Mobilization started on 2nd post – op day with the help of walker.
Avoiding activities including excessive hip flexion and adduction
Avoid squatting or sitting cross legged.