Hip Joint
Osteoarthritis is
the most common disease of the hip joint. This means an age related
wear of the cartilage. However other diseases like rheumatoid
arthritis, malformation like congenital dislocation or osteonecrosis
may end up in osteoarthritis. The patients suffer from increasing
pain in the groin, around the area of the greater trochanter and
of the thigh. Usually the pain is accompanied by some stiffness
due to muscular contractures. The x-rays show a narrow joint line
and osteophytes (bony appositions) at the acetabulum and around
the femoral head. In many cases osteoarthritis is very painful
and does not respond very well to conservative treatment, therefore
the implantation of an artificial hip joint is the only solution.
Similar to the natural hip joint the prosthesis has an acetabulum
(cup), a ball-head, neck and shaft. Today cementless fixation
is the method of choice whereas cement fixation of some components
may be restricted only to revision surgery. In our hospital a
threaded titanium cup is combined with a polyethylene inlay, which
articulates with a ceramic ball-head. The head again is fixed
onto a titanium stem. This stem is brought into the femoral shaft
“press-fit” in a separate step. Sometimes – mainly
in younger patients – a metal ball-head is combined with
a metal gliding surface of the cup. In order to restore a natural
biomechanical function the procedure is planned acurately with
x-rays, transparent templates and tracing paper. This gives the
surgeon a precise idea of the implant sizes to choose.
Our modern implants, which stand the test of time since
1984 have a special titanium surface. Bone “loves”
titanium and after rigid “press-fit” fixation
it is firmly growing onto these surfaces. In the early years
after cementless fixation was introduced, these new implants
were restricted to very young patients. Later on the indication
was gradually enlarged and today it is the method of choice
for almost all patients regardless of their age.
If the bony condition of the patient’s hip joint is
so critical that a primary stable fixation of the implant
may be difficult or even impossible to achieve, the total
prosthesis is plugged in by the help of bone cement. This
gives immediate stability and is still a reliable procedure.
With modern cementing techniques the survival time of the
implant is normally longer than 10 years, whereas cementless
fixation may last much longer.
This means a combination of cementless and cemented components.
Routinely the cup is threaded or fixed in “press-fit”
technique, whereas the stem is cemented. Again there are
different materials like ceramic, polyethylene or metal,
which can be combined as gliding partners like femoral head
and inner surface of the cup.
The hospital stay lasts between 1 and 2 weeks. The patients
are allowed to walk with full weight bearing from the very
first day with the help of two crutches or a walker and
the assistance of a therapist. The affected extremity is
repeatedly placed on a continuous passive motion machine
every day. Later on early functioned treatment is followed
by intensive strengthening program for all the pelvitrochanteric
muscles and the thigh. After wound healing aqua treatment
will start and the patient will be off his crutches after
6 to 8 weeks. In our hospital the discharged patients are
referred directly to some very specialized rehabilitation
centers where they stay between 2 and 4 weeks. Afterwards
the patients should continue to see their therapists 3 times
weekly over 2 to 3 months. After routine procedures and
an uneventful postoperative course and normal rehabilitation
sports like swimming, golf, bicycling or cross country skiing
are possible. Because of the risks of periprostethic fractures
we are not recommending alpine skiing after total hip joint
replacement, but there are always some passionate experts
who cannot resist!
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