Comparison between component designs with different femoral head size in metal-on-metal total hip arthroplasty; multicenter randomized prospective study.

BACKGROUNDS/AIMS: We prospectively studied 78 prostheses with conventional femoral head and 86 prostheses with large head (Magnum) of metal-on-metal total hip arthroplasty (MoM THA) with two years follow-up. METHODS: Clinical outcomes and blood metal ion were evaluated. RESULTS: There were no significant differences of clinical outcomes between groups. 1.17 ± 1.01 µg/L of blood cobalt ion in Magnum was significantly lower than 1.99 ± 2.34 µg/L in conventional group. No dislocation was observed in Magnum while one dislocation in conventional group. MoM THA with large head is useful if the implants are positioned in appropriate alignment, however longer follow-up will be necessary. CLINICAL TRIAL REGISTRATION: NCT01010763 (registered on ClinicalTrials.gov).

Early repair of necrotic lesion of the femoral head after high-degree posterior rotational osteotomy in young patients-a study evaluated by volume measurement using magnetic resonance imaging.

We investigated the repair of femoral head necrosis with extensive necrotic lesions treated by high-degree posterior rotational osteotomy (HDPRO) in young adults and adolescents (mean age; 30.8 years) using magnetic resonance imaging (MRI). HDPRO was performed on 72 hips from 66 cases, and of those, 60 hips from 60 cases were included in this study for data analysis. All cases had extensive collapsed lesion preoperative anteroposterior radiographs. In total, 34 hips were male and 26 were females. In total, 19 had a history of steroid administration, 11 had a previous femoral neck fracture, 7 had no particular etiologic factor, and 4 had a followed slipped capital femoral epiphysis. Antero-inferior viable areas were transferred to the loaded portion below the acetabular roof by this operation. The mean posterior rotational angle was 118.5°. MRI was taken after 1 month, 6 months and 1-year post-operatively. Post-operative necrotic lesion volume compared with the preoperative necrotic lesion volume was defined as lesion volume ratio (%). The reduction of necrotic volume was observed over time, and at 1 year post-operatively, it was 19.4% for patients in their teens, 35.3% for those in twenties, 42.8% for those in their thirties and 59.5% for those in their forties. From this study, we concluded that the extensive necrotic lesions decreased in size within a short period after HDPRO in young patients.

Evaluation of instability after transtrochanteric anterior rotational osteotomy for nontraumatic osteonecrosis of the femoral head.

BACKGROUND: Transtrochanteric anterior rotational osteotomy results in improvement of joint congruity and prevention of progressive collapse and osteoarthritic changes in patients with femoral head osteonecrosis. However, this procedure remains controversial for patients with extensive collapse due to potential osteoarthritis caused by postoperative instability. The purpose of this study was to evaluate hip instability after osteotomy and determine the relation between instability and radiological and clinical outcomes. METHODS: In all, 27 hips of 24 patients that were followed up for a mean period of 3.8 years were included. Instability was defined as more than 1 mm translation of the femoral head in transverse computed tomography scans obtained at 0 degrees and 45 degrees flexion of the hip joint. Hips were divided into instability and stability groups. RESULTS: Eleven hips (40%) developed instability after surgery. Osteophytes on the femoral head in 10 hips of the instability group and 2 hips of the stability group had increased in size at follow-up. There was a significant relation between postoperative instability and osteophyte formation. Joint space narrowing was not seen in any of the cases. There was no significant difference between the groups in either the postoperative intact ratio of the femoral head or the Japanese Orthopaedic Association hip score. CONCLUSIONS: Neither instability nor osteophyte formation on the femoral head after transtrochanteric anterior rotational osteotomy correlated with progressive osteoarthritic changes or clinical outcome in the presence of an adequate femoral head intact ratio facing the weight-bearing area.

Respherical contour with medial collapsed femoral head necrosis after high-degree posterior rotational osteotomy in young patients with extensive necrosis.

Osteonecrosis of the femoral head often occurs in patients under the age of 50 years. In this study, the authors evaluated the effectiveness of high-degree posterior rotation in terms of regaining the spherical contour of severely collapsed necrotic femoral head that was moved medially. They also investigated whether or not subchondral fracture disappeared on the medial femoral head on postoperative anteroposterior radiographs as a result of remodeling after this procedure.

[Transtrochanteric rotational osteotomy for the treatment of non-traumatic osteonecrosis of the femoral head].

Non-traumatic osteonecrosis involving the femoral head frequently occurs in young patients especially due to steroids administration or other some reasons. In cases of extensive lesion of the weight-bearing area, collapse is usually progressive. Preservation of the joint in young patients to avoid joint replacement procedures is important and widely accepted. Transtrochanteric rotational osteotomy for the femoral head osteonecrosis is ideal procedure moving the remained viable femoral head area to the loaded portion below the acetabular roof, thus hip joints can be preserved for long term by remodeling even if the stage is progressed preoperatively. This procedure is technically difficult, but should be common in orthopaedic surgeons.

Posterior rotational osteotomy for nontraumatic osteonecrosis with extensive collapsed lesions in young patients.

BACKGROUND: In young patients with nontraumatic femoral head osteonecrosis with extensive and collapsed lesions, joint preservation is a goal if total joint arthroplasty is to be avoided. We evaluated the effectiveness of a posterior rotational osteotomy in this patient population. METHODS: We reviewed thirty-five hips in twenty-eight young patients with nontraumatic femoral head osteonecrosis treated by posterior femoral neck rotational osteotomy. All femoral heads were collapsed, and seven hips showed joint-space narrowing. Lateral radiographs of the femoral head revealed that 15% of the mean posterior portion and 17% of the mean anterior portion of the femoral head consisted of radiographically apparent living bone. The mean age of the patients (ten women and eighteen men) was twenty-eight years. The mean follow-up period was eight years. RESULTS: Less than six months after surgery, the radiographically apparent area of living bone of the femoral head below the acetabular roof was shown to be 59% on the standard anteroposterior radiograph and 54% on the 45 degrees -flexion radiograph. In thirty-three hips (94%), further collapse of the femoral head was prevented and an adequate amount of living bone was demonstrated on the loaded lateral portion of the femoral head on the final follow-up radiographs. Progressive joint-space narrowing was seen in four hips. CONCLUSIONS: In young patients with osteonecrosis and extensively collapsed lesions of the femoral head, posterior femoral neck rotational osteotomy appears to be effective in delaying the progression of degeneration if an adequate area of living bone can be placed under the loaded lateral portion of the acetabulum. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

A human Langerhans cell-like cell line, ELD-1, promotes CD8 T cells to produce IFN-gamma through CD70-dependent alternative pathway.

A novel pathway of CD8+ T-cell activation by a previously established human Langerhans cell (LC)-like cell line, ELD-1 [Dendritic Cells 9 (1999) 41] is reported. ELD-1 cells possess LC-specific and dendritic cell (DC) lineage-specific markers including Birbeck granules. Intriguingly, ELD-1 cells stimulated interferon (IFN)-gamma production by purified allogeneic CD8+ T cells in an IL-2- but not IL-12-dependent manner, but failed to stimulate CD4+ T cells due to their lack of HLA-DR, CD40, CD80, and CD86 expression. Comparing active and inactive subclones of ELD-1 cells revealed that CD70 was a key molecule determining stimulatory ability. This was confirmed by the ability of transfected CD70-encoding cDNA to confer stimulatory capacity on inactive subclones of ELD-1. Therefore, it is concluded that CD70 expressed on ELD-1 cells has a crucial role in stimulating IFN-gamma production by CD8+ T cells through an alternative pathway which does not require CD4+ T-cell help or CD28-B7 interactions.

IRF-8/ICSBP and IRF-1 cooperatively stimulate mouse IL-12 promoter activity in macrophages.

IRF-8/ICSBP and IRF-1 are IRF family members whose expression is induced in response to IFN-gamma in macrophages. IL-12 is a cytokine produced in macrophages that plays a critical role in host defense. IFN-gamma and bacterial lipopolysaccharide (LPS) induce IL-12p40 transcription, which is necessary for the production of IL-12. We have previously shown that IL-12p40 expression is impaired in ICSBP-deficient mice and that transfection of ICSBP together with IRF-1 can activate IL-12p40 expression in mouse macrophage cells. To further study the role of ICSBP and IRF-1, we investigated murine IL-12p40 promoter activity in the macrophage cell line RAW 264.7. We show here that co-transfection of ICSBP and IRF-1 synergistically stimulates IL-12 promoter activity to a level comparable to that induced by IFN-gamma/LPS. Mutation of the Ets or NFkappaB site previously shown to be important for IL-12p40 transcription did not abolish the activation by ICSBP and IRF-1. However, mutation of the ISRE-like site found downstream from the NFkappaB and C/EBP sites abrogated the activation by ICSBP and IRF-1. Together, these results indicate that ICSBP and IRF-1 cooperatively stimulate murine IL-12 transcription through a novel regulatory element in the murine promoter.