Since the introduction of the Lima Delta Revision system to our department it has become the revision component of choice
inPaprosky Type 2c up to 3b situations. In the author’s opinion the biggest advantages of this system are as follows:
- All components having intimate bone contact are built of Trabecular Titanium (TT), a titanium structure built up by electron beam melting. The friction coefficient of this material is higher than tantalum and the elastic modulus is very close to natural bone.
- The system allows for intraoperative customization:
The trabecular titanium shell is equipped with a hook to be placed in the foramen obturatum, furthermore screw fixation is done by dome screws placed in the direction of the resulting hip force and fins to be fixed by screws to the iliac bone. After proper implantation of the shell special augments can be used to obtain optimal inclination and anteversion angles. If bone voids are apparent they can be filled by specially designed hemispheric modules matching to the implanted diameter of the shell. After having chosen the most suitable inner augment the surgeon can chose between various liner options up to 36mm diameter Delta ceramic inlays or dual mobility liners for maximum stability.
By the end of 2011 the author personally has implanted 45 Lima Delta-Revision Systems, by now none of these
implants had to be revised for aseptic loosening. In 22 cases a hemispheric module to fill bone voids had to be implanted (all Paprosky type 3 defect situations). In 18 cases an angled inner augment was implanted to enhance orientation as far as inclination and anteversion is concerned.
Clinical Cases
This female patient (77 years old) received a total hip arthroplasty more than 25 years ago.
Before the revision we performed a CT scan which revealed massive osteolysis in the area of the cup not to be anticipated on the plain X-Ray.
After removal of the cup the defect had to be classified as a Paprosky type 3b defect situation.
As a solution a Lima Delta-revision System was used consisting of the TT shell fixed with dome screws and lateral screws placed in the os ilium, a hemispherical module to fill the bone void in the iliac bone and a 10 degrees angled augment to correct anteversion and inclination together with a 36 mm Delta ceramic inlay.
Fig. 1
Plain anterioposterior of the patient
presenting with polyethylene osteolysis.
Fig. 2
CT scan depicting osteolysis at the teardrop.
Fig. 3
Direct postoperative result.
D. Neumann, MD
Salzburg County Hospital
Salzburg (Austria)
