Abstract
The use of conventional stems in hip arthroplasty may be difficult in cases of dysplasia, coxa vara or coxa valga, after fracture or proximal femur osteotomy. In fact the morphologic alterations of the proximal femur might require prosthetic components characterised by small size and different neck angles to restore correct joint biomechanics. In these cases we are often compelled to compromise between the ideal implant aneiversion and fit and what we can really achieve. An alternative to conventional prostheses is represented by custom-made prostheses.
For 3 years we have been using the Modulus stem in the treatment of morphologic disorders of the hip. The conic shape of the stem easily fits the different morphologies of the proximal femur, whereas the modularity of the neck makes it possible to correct length, inclination and declination of the femural neck. We studied 59 patients by clinical and radiographic examination before surgery and 1, 3, 6 and 12 months postoperatively. We recorded a statistically significant improvement in the clinical score already at 1 month but this was even better at 6 months after surgery, with respect to the pre-operative examination.
With the use of this prosthesis, the recovery of correct joint biomechanics together with high tribologic standards could improve the implant survival, leading to cost reduction and patient satisfaction.
