Serum ion levels after ceramic-on-ceramic and metal-on-metal total hip arthroplasty: 8-year minimum follow-up.

Alternative bearing surfaces for total hip arthroplasty, such as metal-on-metal and ceramic-on-ceramic, offer the potential to reduce mechanical wear and osteolysis. In the short and medium term, the second generation of metal-on-metal bearings demonstrated high systemic metal ion levels, whereas ceramic-on-ceramic bearings showed the lowest ones. We aimed to verify whether the long-term ion release in metal-on-metal subjects was still relevant at a median 10-year follow-up, and whether a fretting process at the modular junctions occurred in ceramic-on-ceramic patients and induced an ion dissemination. Serum levels were measured in 32 patients with alumina-on-alumina implants (group A), in 16 subjects with metal-on-metal implants (group B), and in 47 healthy subjects (group C). Group B results were compared with medium-term findings. Cobalt and chromium levels were significantly higher in metal-on-metal implants than in ceramic-on-ceramic ones and controls. Nevertheless, ion levels showed a tendency to decrease in comparison with medium-term content. In ceramic-on-ceramic implants, ion values were not significantly different from controls. Both in groups A and B, aluminum and titanium release were not significantly different from controls. In conclusion, negligible serum metal ion content was revealed in ceramic-on-ceramic patients. On the contrary, due to the higher ion release, metal-on-metal coupling must be prudently considered, especially in young patients, in order to obtain definitive conclusions.

Comparison of musculoskeletal and urological functional outcomes in patients with bladder exstrophy undergoing repair with and without osteotomy.

It is controversial as to whether osteotomy, by restoring a more normal pelvic anatomy, might improve the final outcome of bladder exstrophy (BE) repairs. We compared the functional orthopaedic and urological outcomes in BE patients treated with and without osteotomy. Orthopaedic and urological outcomes were compared in eight BE patients treated with osteotomy and six BE patients treated without osteotomy. Orthopaedic evaluation included an assessment of pubic bones dissymmetry, bending of the spine, presence of Trendelenburg or Thomas sign, and presence of out-toeing. Pubic diastasis was ruled out on a plain X-ray of the pelvis. A Pediatric Orthopedic Society of North America (POSNA) questionnaire was administered to every child or his/her caregiver to assess functional outcome. Urological evaluation included an assessment of required continence surgeries and of contemporary continence status. All patients presented a pubic diastasis. This was in median 49 (24-66) mm in patients treated without osteotomy and 42 (25-101) mm in those treated with osteotomy (p = 0.3). There was no difference either in the orthopaedic outcome or in any features of the POSNA questionnaire between groups. Neither was there a difference in the final continence rate nor in the number of additional continence procedures required. Although osteotomy is an essential step in the treatment of many BE patients in order to achieve a tension-free closure of the abdominal wall and bladder, our preliminary results suggest that it does not improve the eventual orthopaedic or urological outcomes of BE.