Kenji Tateda

Cementless total hip replacement with subtrochanteric femoral shortening for severe developmental dysplasia of the hip

Total hip replacement for high dislocation of the hip joint remains technically difficult in terms of preparation of the true acetabulum and restoration of leg length. We describe our experience of cementless total hip replacement combined with a subtrochanteric femoral shortening osteotomy in 20 hips with Crowe grade IV dislocation with a mean follow-up of 8.1 years (4 to 11.5). There was one man and 17 women with a mean age of 55 years (44 to 69) at the time of the operation. After placement of the acetabular component at the site of the natural acetabulum, a cementless porous-coated cylindrical femoral component was implanted following a subtrochanteric femoral shortening osteotomy. The mean Japanese Orthopedic Association hip score improved from a mean of 38 (22 to 62) to a mean of 83 points (55 to 98) at the final follow-up. The mean lengthening of the leg was 14.8 mm (-9 to 34) in patients with iliofemoral osteoarthritis and 35.3 mm (15 to 51) in patients with no arthritic changes. No nerve palsy was observed. Total hip replacement combined with subtrochanteric shortening femoral osteotomy in this situation is beneficial in avoiding nerve injury and still permits valuable improvement in inequality of leg length.

Diagnosis of peri-prosthetic infection at the hip using triple-phase bone scintigraphy

We evaluated triple-phase bone scintigraphy in the differential diagnosis of peri-prosthetic infection in 46 patients with a total hip replacement or bipolar hemiarthroplasty who were due for revision surgery. There were 18 men and 28 women, with a mean age at operation of 64.6 years (28 to 81). We defined peri-prosthetic infection as an increased uptake of radioisotope in all the phases of triple-phase bone scintigraphy and validated these results against the histological and/or microbiology results in every case. The positive and negative predictive values for the presence of infection were 83% and 93%, respectively. The diagnostic sensitivity was 88% and the specificity was 90%. This study indicates that triple-phase bone scintigraphy is a useful tool in the detection of peri-prosthetic infection and offers a cost-effective method of screening.

Experimental rat model for alcohol‐induced osteonecrosis of the femoral head

Alcohol‐induced osteonecrosis of the femoral head (ONFH) is observed in alcohol abusers and patients with alcoholic fatty liver disease. It has been reported that Toll‐like receptor 4 (TLR4) signalling plays a crucial role in the pathogenesis of alcoholic fatty liver disease. We previously reported a corticosteroid‐induced ONFH rat model, and suggested that TLR4 signalling contributes to the pathogenesis of ONFH. Thus, it is thought that the pathogenesis of alcohol‐induced ONFH is probably similar to that of corticosteroid‐induced ONFH. The aim of this study was to develop a new animal model for alcohol‐induced ONFH and to evaluate the relationship between the pro‐inflammatory response via TLRs and the development of ONFH in rats. Male Wistar rats were fed a Lieber–DeCarli liquid diet containing 5% ethanol (experimental group) or dextran (control group) for 1–24 weeks. Histopathological and biochemical analyses were performed. Feeding the ethanol‐containing liquid diet resulted in the development of ONFH with hepatic steatosis, hepatic dysfunction and hyperlipidaemia, whereas feeding the dextran‐containing diet did not cause ONFH. However, we could not recognize any relationship between the pro‐inflammatory response via TLR4 and the development of alcohol‐induced ONFH. Thus in this study we have developed a new rat model for alcohol‐induced ONFH based on the feeding of an ethanol liquid diet. ONFH was observed within seven days from the start of feeding with 5% ethanol‐containing liquid diet. Although this was linked to hepatic steatosis, a TLR4 association was not a feature of this model.

The suppression of TRIM21 and the accumulation of IFN- α play crucial roles in the pathogenesis of osteonecrosis of the femoral head

Osteonecrosis of the femoral head (ONFH), the pathogenesis of which remains unclear, has been observed in autoimmune disease patients treated with corticosteroids. Recently, it has been shown that anti-tripartite motif-containing 21 (TRIM21) autoantibodies, which are often present in patients with systemic lupus erythematosis and Sjögrens syndrome, inhibit the E3 ligase activity of TRIM21. TRIM21 negatively regulates nuclear factor-κB (NF-κB) and interferon regulatory factors (IRFs) 3 and 7, three downstream transcription factors, via toll-like receptor 4 signaling. The aim of this study was to clarify the role of TRIM21 in the pathogenesis of ONFH using an animal model. Male Wistar rats were injected with lipopolysaccharide (LPS) twice and with methylprednisolone (MPSL) or saline three times. N-acetyl cysteine (NAC) was administered either concurrently with MPSL or once daily for the 3 days following the last MPSL injection. The incidence of ONFH in the MPSL group was 23.5%. Co-treatment of NAC and MPSL increased the incidence of ONFH to 55.6%. MPSL treatment decreased the activity of NF-κB in the liver and significantly increased the activity of both IRF3 and IRF7. No significant differences were observed in the activity of any of these three transcription factors between the MPSL and the co-treatment groups. In the femoral head, co-treatment with NAC and MPSL significantly decreased the expression of TRIM21 at 3 h and significantly increased the expression of interferon (IFN)-α at 24 h when compared with the MPSL group. IFN-α is known to induce cell death. These findings suggest that the suppression of TRIM21 in the femoral head causes an accumulation of IFN-α, which in turn leads to the development of ONFH. In conclusion, the suppression of TRIM21 resulting from altered NF-κB and IRF homeostasis accelerates the ONFH in rats treated with corticosteroids following LPS administration.

Weight bearing does not contribute to the development of osteonecrosis of the femoral head

The hip joint is one of the major structures in the human body and the resultant force acting through the hip joint is 300% of body weight. Therefore, weight bearing, as a cause of ischaemia, may contribute to the development of non‐traumatic osteonecrosis of the femoral head (ONFH). However, it remains unclear whether weight bearing is related to the development of non‐traumatic ONFH. Therefore the aim of this study was to clarify the role of weight bearing in the development of non‐traumatic ONFH. Non‐weight‐bearing (NWB) rats were tail suspended to prevent any weight coming to bear on the hindlimbs from day 1 to the time of sacrifice. The weight‐bearing (WB) group rats were also housed individually, although without tail suspension. All rats were injected with lipopolysaccharide and methylprednisolone to promote the development of non‐traumatic ONFH. All animals were sacrificed three weeks after the final methylprednisolone injection. Histopathological analysis was performed. Osteonecrosis of the femoral head was observed not only in the NWB but also in the WB rats; however, no osteonecrosis of the humeral head was observed in either group. We confirmed that non‐traumatic ONFH developed in NWB rats, suggesting that weight bearing does not contribute to the development of non‐traumatic ONFH in rats.

Relationship between the hip joint capsule and piriformis tendon in a simulation of the modified Watson-Jones anterolateral approach in THA cadaver study.

Fifteen fresh frozen cadavers were used for a simulation of the modified Watson‐Jones anterolateral approach in an anatomical study. Several parameters were measured to evaluate the relation between the piriformis tendon insertion and hip joint capsule insertion. The anteroposterior diameter of the piriformis tendon was found to be greater than the medial–lateral diameter, and that the posterior part of the incised hip joint capsule is distant from the piriformis tendon as the piriformis is inserted into the extra‐articular portion. We also found that it was important not to dissect the anteroproximal portion of the greater trochanter to prevent rupture of the piriformis tendon, whereas the posterior portion was relatively safe. Clin. Anat. 26:610–613, 2013.

Chondrosarcoma mimicking MRI of the osteonecrosis of the femoral head: a case report

A 25-year-old female visited our hospital with an 8-year history of arthralgia in the right hip joint. Plain radiography of the hip revealed a well-demarcated radiolucent lesion with a thin sclerotic rim in the epiphysis of the femoral head. T 1 weighted MRI revealed the demarcation line of a low-signal-intensity band in the femoral head. We were aware that this band did not split the signal of adipose tissue in the bone marrow. In cases of osteonecrosis, we usually find a low-signal-intensity band splitting the signal of normal bone marrow. However, we could not see such a low-signal-intensity band in this case. Therefore, we decided to perform other studies. Contrast-enhanced T 1 weighted MRI showed remarkable enhancement in the segment proximal to the low-signal-intensity band, indicating that this lesion might have blood perfusion. We decided to perform a bone biopsy to clarify the diagnosis. Histopathological examination of the biopsy specimen revealed chondrosarcoma. We found that contrast-enhanced MRI plays an important role to rule out osteonecrosis of the femoral head.

Three-dimensional orientation of the acetabulum

This study was designed specifically to determine the normal acetabular orientation and femoral head covering, and whether these are affected by age or sex. Computed tomographic images of normal Japanese hip joints were used (males 60, females 60; mean age 48.3 years, range 15–79 years). Male and female age profiles were matched. The reconstructed 3‐D pelvic images were aligned in the anatomical pelvic coordinate system. The acetabular orientation angles and femoral covering angles were measured in the sagittal, coronal, and horizontal planes. In the sagittal plane, the acetabular orientation angle was operative anteversion (O‐av), and the femoral covering angles were the anterior and posterior center‐edge angles (ACE and PCE). In the coronal plane, they were the Sharp angle (SA) and the lateral center‐edge angle (LCE). In the horizontal plane, they were anatomical anteversion (A‐av) and the anterior and posterior sector angles (ASA and PSA). The O‐av, SA, and A‐av were smaller in the male than the female acetabulum (P < 0.01). SA in both males and females was inversely correlated with age (P < 0.01). Both male PCE and PSA were significantly smaller than those of females, while male ASA was larger than female ASA (P < 0.05). The male acetabulum is directed further outward and downward than the female one. However, this does not indicate that the male acetabulum covers the femoral head more, because there is no significant sex difference in the LCE. Femoral coverage is more posteriorly biased in females than in males owing to pelvic inclination. Clin. Anat. 30:753–760, 2017.

Effect of acute ethanol administration on histone acetylation in mouse brain

drugs, was shown to increase extracellular levels of 5HT in the nucleus accumbens (ACC), the frontal cortex, and the ventral hippocampus in rat. For elucidation of relationship between alcohol-addiction and 5HT system, we produced chronic alcohol treatment mice by the exposure to alcohol vapor for 20 days. C57BL/6J mice showed a significant increase in alcohol drinking behavior after alcohol exposure, whereas there was no significant difference in alcohol drinking of C3H/HeJ, another inbred strain. We then examined expression levels of 5HT receptor family and found that expression of 5HT2C receptor (5HT2CR) was significantly increased in the ACC and the dorsal raphe nucleus (DRN) by chronic alcohol exposure, suggesting that 5HT2CR might be involved in alcohol addiction. 5HT2CR was known to undergo premRNA editing at five sites (site A-E) within exon 5 by deaminating enzymes. As a result of RNA-editing, amino acid substitution occurs at three sites, which alters the ability of the receptor to activate phospholipase C. Here, we investigated RNA-editing changes in alcohol vapor inhalation mice. Either C57BL/6J or C3H/HeJ was exposed to alcohol vapor, followed by the determination of 5HT2CR isoform frequency. C57BL/6J mice exhibited a 1.5-fold increase in site D editing by exposure to alcohol vapor, resulting that 5HT2CR-VXV isoforms were 92% in the ACC. On the other hand, unedited INI-isoform was the most prevalent in C3H/HeJ mice, in spite of alcohol exposure. Furthermore, it was demonstrated that an increase of RNA-editing frequency by alcohol exposure was dependent on the expression level of ADAR1 and ADAR2, RNAediting enzymes. These findings suggest that difference in RNA-editing of 5HT2CR may be associated with alcohol-addiction and -response.