Article
Surgical treatment of congenital iliac dislocation of the hip with two-stage progressive lowering and total hip replacement
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Published: | September 28, 2006 |
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Congenital Iliac dislocation of the Hip (CROWE Grade IV) is a very rare condition. In these cases, Total Hip Replacement can be technically very difficult. In the last 20 years, in dysplastic cases we have used the following protocol: 1) in CROWE Grade I and II we perform a single-stage Total Hip Replacement in a routine manner; 2) in CROWE Grade III we perform a single-stage operation with intra-operative “wake-up” test to control Sciatic Nerve function; 3) in CROWE Grade IV we use an original two-stage procedure with progressive lowering of femoral epiphysis followed by Total Hip Replacement.
The first stage consists in a fascio-mio-arthrolysis (Adductor’s tenotomy, gluteal fasciotomy, Psoas’ Z-lengthening, capsulectomy, femoral head resection) and application of an External Fixator (3 pins in the Ileus and 3 in the Femur). Then we start a progressive lowering of the femoral epiphysis (about 1.5-2 mm/day) until the femoral neck is in front of the Paleo-acetabulum (usually after 2-3 weeks) allowing a correct placement of the cup into the rotation center.
This is a retrospective study about 14 cases (9 females and 4 males, 1 bilateral) of this technique. The average limb lengthening was 6.1 cm. In all cases the cup was placed in the paleo-acetabulum and we have always used a straight, cementless, conical stem (in order to correct neck anteversion and to better fit into the straight femoral canal). Excellent and Good results were 78.5%. No major complications were observed: in particular in no case we had infections of the pins. We had a case of cup aseptic loosening at two years requiring revision with a reinforcement ring and a cemented PE liner.
- The main surgical problem is the cup placement, for the severe hypoplasia of all walls and for the poor bone quality;
- The cup should always be implanted into the Paleo-acetabulum, both for Biomechanical and for cosmetic reasons (no or minimal leg length discrepancy)
- Medialising the cup is very important in order to improve the Glutei lever arm. Care has to be taken not to perforate the Lamina Quadrilatera;
- Lateral grafting according to Harris is necessary only if more than 30% of the cup is uncovered;
- Usually there is no problem with the femoral component (straight to correct neck anteversion);
- CDH patients are young and they need bearing surfaces alternative to PE. We always used ceramic-on-ceramic or metal-on-metal.
Therapeutic study, Level IV.