Bone Impaction grafting vs standard fixationtechnique of the acetabular cup in total hip arthroplasty in patients under 60.

Around 1950 the total hip arthroplasty is placed as a treatment for
debilitating osteoarthritis of the hip. In The Netherlands this surgery is done
around 25.000 times a year. Most important complications are dislocation,
infection, thrombo-embolisms and loosening. Indication. choice of prosthesis,
approach and fixation of components should carefully be considered in placing
THP. In the Isala Clinics approximately 100 patients of 60 years and younger
receive a THP. 70% is reversed hybrid and in 30% both components are placed
with bone cement.

Normal fixation technique
For fixation of the acetabular cup can be chosen for the cemented and
uncemented fixation technique. There are no high qualified studies which prove
superiority of one of both methods. In Europe mainly the cemented technique is
used while in the United States and Australia the uncemented technique is the
standard. In a recent review of Clement et al. no difference is found between
the cemented and uncemented cup in elderly patients. In the younger population
also no difference is found in overall survival between cemented versus
uncemented cup.

Bone Impaction Grafting (BIG) technique
The first description of the BIG technique is done bij Hasting et al. in de mid
seventies where the technique was used in patients with protrusio acetabuli as
a result of rheumatoid arthritis. In 1979 the technique is improved bij Slooff
et al. by creating a contained defect and impaction with autogene or allogene
trabecular bone before placing the cup.Step by step this means that the
acetabulum is prepared using the standard technique. Defect are filled with
bone graft. There can be chosen for a metal mesh for containing the defect.
Next particles of trabecular bone are impacted with a pusher and hammer. De
thickness of impacted bone should be at least 5 mm. In the end, the cup can be
cemented into the created acetabulum. The results of the BIG technique in young
patients with regard to overall survival of the cup are equal or superior to
the survival of the cup with the BIG technique in patients of any age.

Hypothesis
The alternative hypothesis of this study is patient satisfaction on HOOS score
that BIG technique is not inferior to the golden standard 1 year post-surgery
in patients younger than 60 years with osteoarthritis of the hip wherefor total
hip arthroplasty.

Primairy goal
To demonstrate that patient satisfaction with the BIG technique is equal or
better than the standard fixation technique of the cup in the acetabulum in
patients younger than 60 years which have a THA.

Secundairy goals
- To demonstrate that there is a difference in clinical and functional
outcomescores between BIG technique and standard fixation technique in patients
under 60 years with THA.
- To demonstrate that there is a difference in radiological parameters between
BIG technique and standard fixation technique in patients under 60 years with
THA.
- To demonstrate that there is a difference in number of complications between
BIG technique and standard fixation technique in patients under 60 years with
THA.

It concerns a single center, triple blind, randomized controlled trial where
the BIG technique is compared to the standard fixation technique with regard to
fixation of the cup in the acetabulum. Patients will be followed during 10
years after surgery at the outpatient clinic at the standard control moments.
Questionnairies will be part of the control. The controlmoments are based on
regular control moments as stated by the Dutch Orthopedic Society (NOV). Both
groups will be prospectively followed. Per surgeon will be randomized between
BIG and non-BIG.

Surgery will be conducted by the orthopedic dept of the Isala Clinics Zwolle. A
total of 132 patients will have THA of which 66 will have a standard fixation
technique and 66 will have BIG technique. Both surgeons will do 33 standard and
33 BIG techniques.

For surgery the next components will be used:
Stem: BiMetric (Biomet)
Cup: FAL (LINK)
Head: Biolox ceramic

Both groups will have the same bloodsupply- and painmanagement. Post-operative
rehabilitation will take place according to a standardized protocol for THP
with a posterolateral approach and is the same for both groups.Every patient
will receive systemic profylactic antibiotics (cefazolin 2gr intravenous) and
thromboprofylaxis (fondaparinux 0.3mg SC till 5 weeks post-surgery)

The BIG technique is a worldwide common accepted technique. The peroperative
and post-surgery risks are no different than the standard fixation technique. A
disadvantage is that surgery time may be a bit longer. Questionairries will be
taken during the outpatient clinic visits.