[Personal experience with the Wagner revision stem in hip joint reoperations]. / Nase zkusenosti s revizním Wagnerovým dríkem pri reoperacích kycelního kloubu.

PURPOSE OF THE STUDY: Since 1993 we have been using the Wagner revision stem, initially in the length of 265 mm and 305 mm and later also the short stem of 190 mm and 225 mm, for revision surgery with the destruction of proximal femur. This technique provided for primary fixation of the stem in the unaffected femoral bone and creates prerequisites for the bone regeneration and bone formation of the destructed host bone by the loosened implant in the metaphysis and proximal part of diaphysis. MATERIAL AND METHODS: In the period of 1993-1998 we operated on and followed a group of 35 patients (18 men and 17 women), average age 69 years (age range, 52-89). In 32 patients we performed revision surgery of Poldi-Cech stem, twice CF-30 stem and once cementless J + J stem. The average time interval between the primary operation and revision surgery was 10 years (range, 2-22 years). Thirty patients had to be reoperated due to aseptic loosening of the implant and five patients due to infection. Wagner stem was applied no sooner than 6 months after the infect had healed. In the application of the short stem (190 mm or 220 mm) we use Bauer approach (4 times) or extended Bauer approach (4 times), in long stems we use transfemoral approach in our modification: osteotomy is performed from the extended Bauer approach in the frontal plane and the anterior part of femoral cortex is retracted. The retracted anterior part of the femoral cortex femoral bone is fixed back only by hemi-wire loops. RESULTS: Of the total number of 35 operated on 2 patients required revision surgery due to the subsidence of the stem and one removal of the stem in case of complete protrusion of the cup into pelvis. In short stems there were no post-operative complications. Dislocation of the hip occurred in three patients after the implantation of the long stem. After the closed reduction the surgery was not necessary. In one patient there developed an infection 5 months after operation. It was a hematogenous infect resulting from a pyogenic affection of the operated on limb. A two-step revision surgery was performed with a spacer and a subsequent reimplantation of a stem of greater diameter. DISCUSSION: Wagner presents results of 69 patients after the application of his own stem 265 mm and 305 mm long. In 62 patients of the total number no subsidence was encountered, in two cases post-operative dislocation was recorded. Isakson et al. do not consider subsidence resulting in fixation of the stem as a significant factor and correct the difference in the length by shoes. They point out that this method is suitable for the solution of defects of proximal femur in such a way that the implant has a stable fixation and provides for bone formation, restoration of the destructed part of proximal femur in the extent of the original loosened stem. We consider the Wagner technique a significant contribution to the solution of these severe complications. As compared to Wagner, instead of the sagittal plane we perform transfemoral approach in the frontal--horizontal plane which allows operation in the supine position of the patient and a more precise replacement of the cup. In our group of patients we incorrectly used the long stem without transfemoral approach in 3 patients, one patient required revision surgery, in the remaining two patients the period of osteointegration of the stem was substantially longer. CONCLUSION: The Wagner revision stem allows treatment of the destructed proximal part of femur caused by loosening of the stem and polyethylene granuloma. Of great importance is the preservation of the contact of muscles and residual parts of the destructed femoral bone. The short version of the Wagner stem (190 mm and 225 mm) has fully justified itself in revision surgeries of the replacement of the stem in cases of a preserved bone stock. Wagner stem sufficiently bridges the trepanation hole and is safely engaged in the femoral shaft. The long Wagner stem (265 mm and 305 mm) has proved suitable in revision surgeries in cases of thinner cortex and defects in the whole length of the loosened implant. This stem requires a transfemoral approach and a perfect stable anchoring of the stem in the stable skeleton of the femoral shaft. Bone formation and remodelling of proximal femur does not affect the length of the limb. Of great importance is its accurate planning. This procedure is a considerable contribution to the solution of these severe complications.

[Spotorno CLS Cup in Revision Arthroplasty of the Hip.]. / Pouzití standardní necementované jamky CLS v revizních indikacích.

UNLABELLED: PURPOSE OF THE STUDY Revision surgery for the loosening of total hip arthroplasty with the use of cemented implants does not guarantee good long-term results. The current trend prefers the use of cementless implants, particularly of the press-fit type. In our group of patients with aseptic loosening of the acetabular cup with a preserved acetabular bone stock without segmental defects we used for the revision surgery a Spotorno CLS cementless cup. MATERIAL The group comprised 33 patients, 29 women and 4 men, of the average age of 66 years, with the loosened acetabular component, of which 31 had originally a cemented Poldi cup and 2 a cementless threaded Walter-Motorlet cup. Cup revision only was performed in 25 cases, both components (cup and stem) were replaced in 8 cases. METHODS We used a standard cementless Spotorno CLS cup. In case of a preserved circular bone stock of acetabular rim the cup was implanted in the standard position. Cavity defects were filled by cancellous bone grafts. In case of poor anatomical bone stock the cup was implanted deeper in acetabular cavity usually in a more varus position and rarely in valgus position depending on the localisation of segmental defect. RESULTS The average follow-up was 38 months (range, 16-63 months). In one case there occurred aseptic loosening after 12 months and the second revision surgery was necessary in order to replace the implant by the same type of a greater size. In one case after 6 months there developed a hematogeneous infection and the implant was replanted by a two-stage procedure. In the remaining cases osteointegration took place in the course of 12 months after the operation. In 7 cases the cups were implanted in a slightly varus/valgus position necessitated by the acetabular bone stock, without any impact on the osteointegration or function. DISCUSSION The disadvantage of cemented implants in the revision surgery consists in the limited possibility of the integration of cemented mantle and the destructed bone interface. The advantages of cementless implant in the revision surgery of a loosened cup is confirmed by a number of authors but they relate mainly to press-fit cups. The data on the use of Spotorno CLS expansion cup in the revision surgery are rare. Our group with a short follow-up demonstrates that the integration and the function of the CLS cup as a revision implant seems to be reliable. The main prerequisite, however, is a good acetabular bone stock without greater segmental defects. Cavity defects may be filled in by autologous or homologous cancellous bone grafts. The CLS cup may be fixed, if necessary, in a slightly non-anatomical position without any impairment of the function. It includes mainly the cases of the ovoid shape of acetabulum when the cup is implanted in the acetabula roof in greater varus slope than recommended by the author of implant. CONCLUSIONS The Spotorno CLS cementless expansion cup as a revision implant in the right indication brings good short term results on condition of a good primary stability of the implant and a spherical acetabulum without great segmental defects. KEY WORDS: THA, revision surgery, cementless CLS cup.