UNCEMENTED TOTAL HIP REPLACEMENT

1. Uncemented Total Hip
Replacement
Dr. Nabeil Sufyan

2. INTRODUCTION
• Total hip arthroplasty is an operative
procedure in which the diseased and
destroyed hip joint is resected and
replaced with a new bearing surface.
• Patients with arthritis can now look to
THA with the object of maintaining
stability, while relieving pain,
increasing mobility and correcting
deformity.

3. Anatomy of hip joint
• Head of femur articulates with the
acetabulum of pelvis to form hip joint
• This is a ball and socket variety of
synovial joint.
• The range of movements which permits
is less than that of shoulder joint, but the
strength and stability are much greater.

4. Head of the femur
• Head of femur forms more than a half of a
sphere, and is covered with hyaline cartilage
except at the fovea capitis.
• directed upwards, medially and slightly
forwards
Throughout ROM:
• 40% of femoral head is in contact with
acetabular articular cartilage.
• 10% of femoral head is in contact with labrum.

5. • Hip joint is unique in having a high degree of both stability as well as
mobility
• The stability or strength depends upon :
– The depth of acetabulum which is increased by the acetabulur labrum.
– The strength of the ligaments and the surrounding muscles.
– Length and obliquity of the neck of femur which increases the range of
movement

6. Ligaments
They are :
• Fibrous capsule
• Iliofemoral ligament or ligament of bigelow
• Pubo-femoral ligament
• Ischio-femoral ligament
• Ligamentum teres
• Transverse ligament of acetabulum

7. Neck shaft angle
• It is the angle between the axis of
the femoral neck and the long axis
of the femoral shaft.
• On average, it is 135 degrees in
the adults.

8. Anteversion or Angle of femoral torsion
• Refers to the degree of forward
projection of femoral neck from
the coronal plane of the
femoral shaft.
• In an adult, it is about 10-15
degree.

9. Forces Acting on Hip
• To describe the forces acting
on the hip joint, the body
weight may be depicted as a
load applied to a lever arm
extending from the body’s
center of gravity to the center
of the femoral head
• The abductor musculature, acting
on lever arm extending from the
lateral aspect of the greater
trochanter to the center of the
femoral head.

10. • Force on hip act in coronal and saggital
direction
• Coronal- tend to deflect stem medially ,
saggital ( in flexed hip)- tend to deflect
stem posteriorly
• Hence Implanted femoral components
must withstand substantial torsional
forces even in the early postoperative
period

11. Head and Neck Diameters
• The neck with the smaller head
tends to impinge on the edge of
the cup during a shorter arc of
motion which tends to loosen the
components and dislocate the joint.
• The deep socket and beveled
edges and the greater diameter of
the head in comparison to the neck
are the features that allow a
greater range of motion.

12. Inducation For THA
• The primary indication for THA is incapacitating PAIN. Pain in the hip in the
presence of destructive process as evidenced by X-ray changes is an
indication.
• THA is an option for nearly all patients with diseases of the hip that cause
chronic discomfort and significant functional impairment.
• Patients with limitation of movement, leg length inequality and limp but with
little or no pain are not the candidates for THR.

13. • Arthritis
Rheumatoid
Juvenile rheumatoid (Still disease) Ankylosing spondylitis
• Degenerative joint disease (osteoarthritis, hypertrophic)
Primary
Secondary
Slipped capital femoral epiphysis Congenital dislocation or dysplasia of hip Coxa plana
(Legg-Calvé-Perthes disease) Paget disease
Traumatic dislocation
Fracture, acetabulum Hemophilia

14. • Osteonecrosis
Postfracture or dislocation
Idiopathic
Slipped capital femoral epiphysis
Hemoglobinopathies (sickle cell disease)
Renal disease
Cortisone induced, Alcoholism, Caisson disease, Lupus
Gaucher disease.
Nonunion, femoral neck and trochanteric fractures with head involvement
• Pyogenic arthritis or osteomyelitis
Hematogenous
Postoperative

15. CONTRAINDICATIONS TO TOTAL
HIP ARTHROPLASTY
Absolute contraindications for total hip arthroplasty include
• Active infection of the hip joint or any other region
• Any unstable medical illnesses that would significantly increase the risk of
morbidity or mortality.

16. Other relative contraindications include:
• Morbid obesity
• Severe dementia
• Tobacco use
• Severe osteoporosis
• Untreated skin conditions such as psoriasis
• Absence or relative insufficiency of the abductor musculature.

17. Hip Replacement Components
• Acetabular component -
consists of two components
– Cup - usually made of titanium
– Liner - can be plastic, metal or
ceramic
• Femoral components
• Head
Neck
stem

18. Femoral Components
• Neck length and offsets :
The ideal femoral reconstruction reproduces the normal center of rotation of
femoral head, which can be determined by
-Vertical height (vertical offset)
-Medial head stem offset ( horizontal offset)
-Version of the femoral neck (anterior offset)

19. • Vertical offset- LT to center of the femoral
head. Restoration of this distance is essential in
correction of leg length.
• Medial head stem offset- distance from the
center of the femoral head to a line through the
axis of the distal part of stem.
• Medial offset if inadequate, shortens the
moment arm – limp, increase, bony
impingement and dislocation.
• Excessive medial offset –increase stress on
stem and cement which causes stress fracture
or loosening.
• Version of the femoral neck : important in
achieving stability of the prosthetic joint. The
normal femur has 10-15 degree of anteversion.

20. CLASSIFICATION OF TOTAL HIP FEMORAL COMPONENTS :
• Cemented :
• Non cemented –
Press Fit
Porous Metal
• Bipolar
• Ceramic
• Polyacetate

21. • Range of head sizes – 22, 26, 28 & 32 mm.
• Incidence of dislocation is higher for smaller head.
• Neck diameter : Original charnleys was 12.5 mm but has been reduced to
10.5 mm – reduced neck diameter avoids impingement during flexion and
abduction.
• Range of stem lengths -120 mm to 170 mm.
• The main problem is mechanical loosening and extensive bone loss
associated with fragmented cement

22. Acetabular Components
• The articulating surface of all acetabular components is made of UHMWPE. Most systems
feature a metal shell with an outside diameter of 40 to 75 mm which is mated to a polythene
liner.
• optimum position for the prosthetic socket which should be inclined 45⁰ or less to maximize
stability of the joint.(normal 55⁰)
Types :
• Cemented acetabular components.
• Cementless acetabular components.
• Custom made acetabular components

23. CEMENTLESS ACETABULAR
COMPONENTS
• Most cementless acetabular components are porous coated over their
entire circumference for bone ingrowth.
• Most systems feature a metal shell with an outside diameter of 40 to 75
mm that is used with a modular liner. With this combination, a variety of
femoral head sizes, typically 22 to 40 mm, can be accommodated
according to the patient’s need and the surgeon’s preference

24. • With the adoption of newer bearing
surfaces such as ceramic-on-ceramic
and metal-on-metal designs,
manufacturers have introduced
acetabular components that will accept
any of a variety of insert types. Newer
locking mechanisms typically incorporate
a taper junction near the rim for hard
bearings. The polyethylene locking
mechanism may be recessed within the
shell where it is less susceptible to
damage if impingement from the femoral
neck occurs

25. • To maintain sufficient thickness of the polyethylene, a smaller head size
must be used with an acetabular component that has a small outer
diameter.
• Most modern modular acetabular components are supplied with a variety
of polyethylene liner choices

26. • A dual mobility acetabular component is
an unconstrained tripolar design. The
implant consists of a porouscoated metal
shell with a polished interior that accepts a
large polyethylene ball into which a
smaller metal or ceramic head is inserted
• The two areas of articulation share the
same motion center. The design
effectively increases the head size and the
head-neck ratio of the construct.
• Implant impingement is reduced and
stability is improved without reducing the
range of motion as with constrained
implants.

27. Surgical Approaches and Techniques
SURGICAL APPROACHES AND TECHNIQUES
• Each approach has relative advantages and drawbacks. Choice of specific
approach for THR is largely a matter of personnel preference.
• Posterolateral approach with patient in lateral position without greater
trochanter osteotomy and dislocating the hip posteriorly is commonly
done.

28. POSTEROLATERAL APPROACH
• Patient firmly anchored in the straight
lateral position.
• Slightly curved incision centered over
the greater trochanter.
• Skin incision proximally at a point level
with the anterior superior iliac spine
along a line parallel to the posterior
edge of the greater trochanter.
• Distally to the center of the greater
trochanter and along the course of
the femoral shaft to a point 10 cm
distal to the greater trochanter.

29. • Divide the subcutaneous tissues along the skin incision in a single plane
down to the fascia lata and the thin fascia covering the gluteus maximus
superiorly.
• Divide the fascia in line with the skin wound over the center of the
greater trochanter.
• Insert a large self-retaining retractor beneath the fascia lata at the level
of the trochanter.
• Divide the trochanteric bursa and bluntly sweep it posteriorly to expose
the short external rotators and the posterior edge of the gluteus
medius.

30. Device for intraoperative leg-length measurement.
Sharp pin is placed in pelvis above acetabulum or iliac crest,
and measurements are made at fixed point on greater trochanter.
Adjustable outrigger is calibrated for measurement of leg length
and femoral offset

32. • Flex the knee and internally rotate the extended hip to place the short external
rotators under tension.
• Palpate the sciatic nerve as it passes superficial to the obturator
internus and the gemelli.
• Palpate the tendinous insertions of the piriformis and obturator internus
and place tag sutures in the tendons for later identification at the time of
closure.
• Divide the short external rotators, including at least the proximal half of
the quadratus femoris.

33. • Divide the entire exposed portion of the capsule immediately adjacent to its femoral
attachment. Retract the capsule and preserve it for later repair
• insert a Steinmann pin into the ilium superior to the acetabulum and make a mark at a
fixed point on the greater trochanter.
• Dislocate the hip posteriorly by flexing, adducting, and gently internally rotating the hip.
• Place a bone hook beneath the femoral neck at the level of the lesser trochanter to lift the
head gently out of the acetabulum.
• Ensure that the superior and inferior portions of the capsule have been released as far
anteriorly as possible.
• Remove the femoral head segment with a corkscrew.
• Use the stem size and neck length trials determined by preoperative templating.

34. žThree retractors are then utilized to gain exposure ofthe acetabulum:
Anterior, superior, and inferior.
žThe anterior retractor should be placed carefully to avoid injury to the
femoral neurovascular bundle.
žThis can be done using a Cobb elevator to gently develop the plane
between the anterior acetabular wall and the overlying anterior capsule.
žPositioning the hip in flexion to relax the neurovascular structures during this
maneuver is also helpful.

35. ž After the plane is developed, the Cobb is replaced with a blunt Hohman.
ž A second retractor is then placed superior to the acetabulum to protect and elevate
gluteus muscle away from the surgical field.
ž A Mueller is placed posterior and inferior to the acetabulum against the ischium.
ž Releasing the inferior hip capsule at this time between the anterior and posterior
retractors helps improves acetabular visualization and assists with
insertion/removal of acetabular reamers and components

36. ž The labrum, pulvinar, and any loose soft tissues are excised,
followed by routine acetabular reaming.
ž The transverse acetabular ligament, reamer position relative
to the floor, and cup-positioning guides are used to establish
proper version and inclination during both reaming and cup
insertion.

37. ž After completing acetabular reconstruction, the leg is placed in a
figure four position with the operative foot on the anterior portion of
the contralateral knee and the ipsilateral knee flexed to 90°.
ž Muellers are placed on the medial aspect of the proximal femur and
posterior to GT to lateralize the proximal portion of the femur while
also displacing the posterior soft tissues

38. IMPLANTATION OF CEMENTLESS
ACETABULAR COMPONENT
• The size of the implant is determined by the diameter of the last reamer
used.
• Fixation must be augmented with fins, spikes, or screws. A component
that is oversized by 1 to 2 mm can be press-fit into position to provide a
greater degree of initial stability
• Expose the acetabulum circumferentially and retract or excise any
redundant soft tissues that may be drawn into the acetabulum as the
component is inserted.
• Prepare the appropriate recesses for any ancillary fixation devices present
on the component as specified by the manufacturer’s technique

39. • Attach the acetabular component to the positioning device included with
the system instrumentation. Be certain of the means by which the
positioning device orients the socket.
• The optimal inclination of the component is 40 to 45 degrees. The optimal
degree of anteversion is 20 degrees
• The transverse acetabular ligament also is a useful anatomic reference for
component positioning. Place the component parallel and just superior to
the ligament

40. • If the femoral component is of an anatomic design, with anteversion
already built in the femoral neck, position the socket in only 10 to 15
degrees of anteversion..
• Maintain the alignment of the positioning device as the component is
impacted into position.
• A change in pitch is heard as the implant seats against subchondral bone.
Reassess the positioning; if it is satisfactory, remove the positioning device

41. • Examine the subchondral bone plate through any available holes in the
component to confirm intimate contact between implant and bone. If a gap
is present, impact the component further.
• If screws are to be used for ancillary fixation, place them preferably in the
postero-superior quadrant.
• Confirm screw length with an angled depth gauge. Self tapping 6.5-mm
screws are preferred. Use a screw holding clamp to maintain alignment of
the screw as the self-tapping threads become engaged

42. • If the drill bit exits in close proximity to the sciatic nerve, use a screw
slightly shorter than the measured length or choose a different hole.
• If screws must be placed in the anterior quadrants to gain fixation, perform
drilling and screw insertion with utmost care. Use the shortest length drill
bit with light pressure on the drill to avoid plunging as it penetrates the
opposite cortex.
• There should be no detectable motion between implant and bone. If the
fixation is unstable, place additional screws or consider using a cemented
device

43. • With a curved osteotome, remove any osteophytes that protrude beyond
the rim of the acetabular component.
• Irrigate any debris from within the metal shell
• Insert the polyethylene liner ensuring that no soft tissue becomes
interposed between the polyethylene liner and its metal backing because
this would prevent complete seating and engagement of the locking
mechanism.

44. A, Socket positioning in abduction. B, Anteversion. C, Insertion of liner

45. IMPLANTATION OF CEMENTLESS
FEMORAL COMPONENT
• Younger patients with good quality femoral bone are the best candidates
for cementless femoral fixation.
• Straight femoral components require straight, fully fluted reamers.
• Anatomic-type components may require femoral preparation with flexible
reamers to accommodate the slight curvature of the stem.

46. A. Removal of remaining lateral edge of femoral neck and medial portion of greater
trochanter with box osteotome
• A

47. B .Reaming of femoral canal. Hand or power reamers must be lateralized
into greater trochanter to maintain neutral alignment in femoral canal

48. • Expose the proximal femur as described in postero-lateral approach
• Insert the smallest reamer at a point corresponding to the piriformis fossa.
The insertion point is slightly posterior and lateral on the cut surface of the
femoral neck.
• After the point of the reamer has been inserted, direct the handle laterally
toward the greater trochanter. Aim the reamer down the femur toward the
medial femoral condyle.Generally, a groove must be made in the medial
aspect of the greater trochanter to allow proper axial reaming of the canal

49. • Proceed with progressively larger reamers until diaphyseal cortical
reaming is felt. Assess the stability of the axial reamer within the canal
• Remove the residual cancellous bone along the medial aspect of the neck
with precision broaches. Begin with a broach at least two sizes smaller
than the anticipated stem
• Push the broach handle laterally during insertion to ensure that enough
lateral bone is removed and avoid varus positioning of the stem
• Rotate the broach to control anteversion

50. • Align the broach to match precisely the axis of the patient’s femoral neck.
• Proceed with progressively larger broaches, maintaining the identical
alignment and rotation. Use even blows with a mallet to advance the
broach.
• The broach should advance slightly with each blow of the mallet. If motion
ceases, do not use greater force to insert the broach.

51. • If a broach sized smaller than
that anticipated by templating
cannot be fully inserted, the
broach may be in varus.
Lateralize farther into the
greater trochanter with
reamers to achieve neutral
alignment in the femoral canal
and proceed with broaching
Femoral broaching. Progressively larger
broaches are inserted, lateralizing each one to maintain neutral
alignment.

52. • Seat the final broach to a point where it becomes axially stable within the
canal and would not advance farther with even blows of the mallet.
• Assess the fit of the broach within the canal. The broach should be in
intimate contact with a large portion of the endosteal cortex, especially
posteriorly and medially

53. • When adequate stability has been obtained, make the final adjustment of
the neck cut.Precise preparation of the neck is essential if a collared stem
is to be used; this step is optional when a collarless stem design is
employed.
• Select the trial neck component determined through preoperative
templating. In most systems, the trial head and neck components fit onto
the trunnion used for attachment of the broach handle.
• If the neck length seems satisfactory, irrigate any debris out of the
acetabulum

54. • Apply traction to the extremity with the hip in slight flexion. Gently lift the
head over the superior lip of the acetabulum and any elevation in the
polyethylene liner that may have been inserted
• Move the hip through a range of motion. Note any areas of impingement
between the femur and pelvis or between the prosthetic components with
extremes of positioning

55. • The hip should be stable (1) in full extension with 40 degrees of external
rotation; (2) in flexion to 90 degrees with at least 45 degrees of internal
rotation; and (3) with the hip flexed 40 degrees with adduction and axial
loading (the so-called position of sleep.
• If stability is acceptable, note the position of any elevation of the trial
polyethylene liner, redislocate the hip by flexion and internal rotation, and
gently lift the head out of the acetabulum. Remove the trial components
and broach.

56. Planing of calcar with precision
reamer place over broach
trunnion.
Assembly of trial head and neck segments
determined from preoperative templating.

57. • If a modular trial polyethylene liner has been used, place the final
component at this time
• Regain exposure of the proximal femur and remove any loose debris within
the femoral canal, but do not disturb the bed that has been prepared
• Insert the appropriate-size femoral component. Insert the stem to within a
few centimeters of complete seating by hand. Reproduce the precise
degree of anteversion determined by the broach

58. • Gently impact the stem down the canal. Use the driving device provided
with the system or a plastic-tipped pusher. Use blows of equal force as the
component is seated.
• Insertion is complete when the stem no longer advances with each blow of
the mallet.
• An audible change in pitch usually can be detected as the stem nears final
seating
• Test the stability of the implanted stem to rotational and extraction forces.

59. • Carefully inspect the femoral neck and greater trochanter for any fractures
that may have occurred during stem insertion..
• If an incomplete fracture occurs with extension only at the level of the
lesser trochanter, place a cerclage wire around the femur above the lesser
trochanter.
• Reinsert the stem and ensure the cerclage wire tightens as the stem is
seated into position. Reassess the stability of the implanted stem.

60. • If the fracture extends below the level of the lesser trochanter,a longer
stem with greater distal fixation is required.
• Wipe any debris from the Morse taper segment of the prosthetic neck and
carefully dry it.
• Place the prosthetic head of appropriate size and neck length onto the
trunnion and affix it with a single blow of a mallet over a plastic-capped
head impactor.

61. • Remove any debris from the acetabulum and again reduce the hip. Ensure
no soft tissues have been reduced into the joint.
• Confirm the stability of the hip through a functional range of motion

62. COMPLICATIONS
• MORTALITY
According to the American College of Surgeons National Surgical Quality
Improvement Program, the 30-day mortality rate is 0.35% for primary total
hip arthroplasty. Mortality at 90 days postoperatively in the United States
Medicare population is 1% for primary total hip arthroplasty and 2.6% for
revision surgery

63. • HEMATOMA FORMATION
• HETEROTOPIC OSSIFICATION
• THROMBOEMBOLISM
• NEUROLOGIC INJURIES
• VASCULAR INJURIES
• LIMB-LENGTH DISCREPANCY
• DISLOCATION

64. • FRACTURES

65. POSTOPERATIVE MANAGEMENT
OF TOTAL HIP ARTHROPLASTY
• Ideally, rehabilitation should begin before the operation.A patient who is
motivated, informed, and has appropriate goals is a better participant in the
rehabilitation process
• A preoperative session may be used to teach the appropriate mechanisms
for transfers, the use of supportive devices, how to negotiate steps,
dislocation precautions, and the anticipated schedule for recuperation and
hospital discharge

66. • In the immediate postoperative period, the hip is positioned in
approximately 15 degrees of abduction while the patient is recovering from
the anesthetic. For patients treated with a posterior approach, we use a
triangular pillow to maintain abduction and prevent extremes of flexion

67. • If patient discomfort and anesthesia recovery allow bed exercises and
limited mobilization may be initiated on the afternoon after surgery. Deep
breathing, ankle pumps, quadriceps and gluteal isometrics, and gentle
rotation exercises are begun.
• When anesthetic recovery and pain allow, the patient can sit on the side of
the bed or in a chair in a semi-recumbent position. One or two pillows in
the seat of the chair helps prevent excessive flexion. An additional pillow
between the thighs limits adduction and internal rotation.

68. • Gait training usually can begin on the afternoon after surgery. Most elderly
patients require a walker for balance and stability. Many younger patients
require a walker for only a few days and progress to crutches.
• With cementless, porous ingrowth implants, many authors recommend
limited weight bearing for 6 to 8 weeks, whereas others encourage early
weight bearing as comfort allows.
• The patient can be discharged when able to get in and out of bed
independently, walk over level surfaces, and climb a few steps.
• Printed instructions reviewing the home exercise program and precautions
to prevent dislocation are helpful

69. FOLLOW UP
• Follow-up visits are made at 6 weeks, 3 months, 1 year, and periodically
thereafter.
• Routine radiographs are made at 2-year intervals and compared with
previous films for signs of loosening, migration, wear, and implant failure.
• Regular follow-up is advised because loosening, wear, and osteolysis may
occur in the absence of clinical symptoms, and revision is more difficult if
the diagnosis is delayed until symptoms occur.