Introduction: Hip replacement prosthesis infection is a severe complication of ever increasing incidence. Currently there is controversy as to whether prosthetic revision surgery should be carried out in one or two stages and whether cemented or uncemented prostheses should be used.

Materials and methods: This is a retrospective study of 17 cases of chronic infections of hip replacements that were revised in one-stage procedures between 1996 and 2005 in our center. Mean follow-up is 3.4 years. We analyzed the functional status of the hips before and after revision using the Merle D’Aubigne scale, x-rays, and supplementary tests for diagnosis and decisions on treatment.

Results: The functional score at the end of the follow-up was 16.17 (Merle D’Aubigne scale). The most common pathogen is coagulase-negative staphylococci. Acute phase reactive elements reached normal levels. X-ray control does not show any alterations or signs of loosening. No subsequent revisions have been performed.

Conclusions: The diagnosis and treatment of prosthetic revision requires correct preoperative assessment and planning. Differential diagnosis of aseptic versus septic loosening in chronic infections is complex; in some cases it is necessary to wait for definite culture results for a surefire diagnosis. We think that in selected chronic cases of septic loosening of the hip due no non-multi-resistant organisms, one-stage revision using a Wagner osteotomy for diaphyseal cleaning combined with a hydoxyapatite-coated stem makes it possible to achieve good functional results and control infection, decreasing the morbidity and cost of a two-stage revision.

Aims: The purpose of this study is to compare the clinical outcome, radiological integration and survivorship associated with a porous coated stem and those associated with a hydroxyapatite-coated stem in a consecutive serie of uncemented total hip replacements.

Methods: Between 1992 and 1995, 188 primary uncemented hip arthroplasties were performed at our institution using either a proximal porous-coat or a fully HA-coated stem. Mean age and weight and distribution of sex and primary diagnosis were similar in both groups. Ninety-eight hips from the HA group (group 1) and 69 from the porous-coated group (group 2) had a complete clinical and radiographic follow-up. The average duration of follow-up period for group 1 and 2 was 10.12 and 9.8 years respectively (range,9 to 12). Parameters such as implant migration and bone remodelling were especially evaluated and compared in both groups on postoperative X-rays.

Results: In group 2 , 8 hips (11.8%) needed revision for aseptic loosening and 24 additional hips (34.7%) showed non-progressive lucent lines; distal migration of the stem was seen in 9 cases(13.04%). In contrast no hip in group 1 required revision and all but two hips in this group showed radiological integration; no stem showed distal migration. Harris hip score at follow-up was better in group 1 (p= 0.05) due to a higher incidence of thigh pain in group 2 (23% vs 0%). Significant differences between both groups (p=0.02) were also observed in predicted rate of survival at 10 years with revision for aseptic loosening as the endpoint.

Conclusion: In our series the HA-coated stem has provided significantly better outcomes in terms of clinical scores, radiological integration and survivorship rates than porous-coated stem.

Aims: The bone – conductive proparties of hydroxyapatite (HA) coatings are attractive in revision surgery with bone loss. The purpose of this study is to analyse the clinical and radiological results of 55 cases of revision hip arthroplasty using hydroxyapatite femoral stems. Methods: Between May 1995 and October 2000 we performed 55 patients total hip replacements in 50 patients (5 bilateral) using hydroxyapatite (HA) – coated femoral stem. The average age of the patients at the time of the index revision was 67 years (range 44–84). Clinical evaluation was by a Merle d’Aubigne Score (preoperative 6.54 points). Radiological evaluation used the AAOS system for preoperative films and scaring system after Engh for the postoperative films. Bone grafts was required in 35 cases. Results: Postoperative Merle d’Aubigne score was 17.25 points. Complications: 3 dislocations, one transitory nerve palsy and 14 associated intraoperative fractures. All grafts consolidated. None of the femoral stem components required revision because of aseptic loosening. No radiologically progressive lucency or signs indicating a loose implant were visible in anycases. There were no cases of femoral stem migration. Conclusions: We conclude that the hydroxyapatite femoral stem is suitable for implantation at revision hip arthroplasty and can give good results in the short to medium term, because the clinical and radilogical results are excellent, with a early consolidate fractures.

Aims: The purpose of this study is to evaluate clinic and radiological results in acetabular revision using hemispherical hydroxyapatite (HA)-coated cups and morselized allograft in the presence of sever bone defects (Paprosky type IIIA). Methods: From a serie of 218 patients having revision total hip arthroplasty between1995 and 1999, 42 hips in 42 patients were included in this retrospective study. The inclusion criteria were:

Ð Presence of sever bone loss without pelvic discontinuity (Paprosky type IIIA).

All revisions were carried out by the same surgical team using a posterolateral approach. Morselized allograft was used in all cases. The mean age at the time of revision surgery was 70 years (range, 48 to 84). The mean follow-up was 52 months (range, 36 to 81). In 39% of the cases a extra large cup (more than 60 mm) was used. Results: the average Merle dñAubignŽ score rose from 7.3 points preoperatively to 17.2 points at follow-up (90% of the patients were pain free). All the cups remained radiologically stable at follow-up. Partial resorption of the allograft without jeopardising implant stability was detected in 4 cases (10%); all the rest showed radiological consolidation and remodelling of the medial wall of the acetabulum. Conclusions: these results strongly support the use of hemispherical HA-coated cups, combined with morselized allograft, in acetabular revision even in the presence of major acetabulum bone loss.