Total hip arthroplasty after failed transtrochanteric rotational osteotomy for osteonecrosis of the femoral head: analysis of three-dimensional morphological features.

BACKGROUND: In total hip arthroplasty (THA) after failed transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH), deformity of the proximal femur has been reported to affect stem placement. The aims of this study were to evaluate the morphological changes in the proximal femur, muscle atrophy, and soft tissue thickening in THA after TRO and the clinical outcomes. METHODS: The TRO group included 17 patients (18 hips) who underwent THA after failed TRO. The control group included 21 patients (28 hips) who underwent primary THA for ONFH. To evaluate the deformity of the proximal femur before THA, we measured the anteroposterior and mediolateral diameters of the femur on computed tomographic slices 5 mm proximal to the lesser trochanter. To evaluate muscle atrophy and soft tissue thickening, we measured the thicknesses of the psoas major, iliac, and gluteus medius muscles and the anterior capsule of the hip joint. RESULTS: The ratio of the anteroposterior to mediolateral diameters of the proximal femur was significantly greater in the TRO group (p < 0.01). The thicknesses of the muscles did not differ between the two groups, whereas the anterior capsule was significantly thicker in the TRO group (p < 0.05). Varus or valgus stem alignment (> 3°) was frequent in the TRO group (p < 0.01). CONCLUSIONS: The round shape of the proximal femur was deformed after TRO compared with primary THA for ONFH, which may have caused malposition of the stem. In addition, we should pay attention to anterior protrusion of the proximal femur and thickening of the anterior capsule.

Patterns of C-reactive protein trends during clozapine titration and the onset of clozapine-induced inflammation: a case series of weekly and daily C-reactive protein monitoring.

Background: International guidelines for clozapine titration recommend measuring C-reactive protein (CRP) weekly for 4 weeks after clozapine initiation to prevent fatal inflammatory adverse events, including myocarditis. However, limited evidence exists regarding whether weekly CRP monitoring can prevent clozapine-induced inflammation. Aims: We examined the relationship between CRP trends and the development of clozapine-induced inflammation. We also explored the usefulness and limitations of CRP monitoring during clozapine titration. Method: This study presents 17 and 4 cases of weekly and daily CRP monitoring during clozapine initiation, respectively. Results: Among 17 patients with weekly CRP measurements, 7 had fever. Elevated CRP levels were detected before the onset of fever in two of the seven patients. Of the five remaining patients, the CRP levels on a previous test had been low; however, the fever developed suddenly. Of the 10 patients with no fever under weekly CRP monitoring, three had elevated CRP levels >3.0 mg/dL. Refraining from increasing the clozapine dose may have prevented fever in these patients. Among four patients with daily CRP measurements, two became febrile. In both cases, CRP levels increased almost simultaneously with the onset of fever. Conclusion: Weekly and daily CRP monitoring during clozapine titration is valuable for preventing clozapine-induced inflammation, assessing its severity, and guiding clozapine dose adjustments. Weekly CRP monitoring may not adequately predict clozapine-induced inflammation in some cases. Consequently, clinicians should be aware of the sudden onset of clozapine-induced inflammation, even if CRP levels are low. Daily CRP monitoring is better for detecting clozapine-induced inflammation.

Visualization of acetabular coverage with radar chart before and after curved periacetabular osteotomy in dysplastic hips.

BACKGROUND: Curved periacetabular osteotomy (CPO) is indicated for patients with developmental dysplasia of hip (DDH) to prevent progressive osteoarthritis. Patients with DDH have not only lateral acetabulum dysplasia but also anterior and posterior dysplasia. The full circumference acetabular coverage angle (ACA) of the femoral head should be evaluated preoperatively. This study aimed to determine the full circumference ACA in the patients with DDH before and after CPO compared with the coverage in normal patients. METHODS: Twenty-three patients (a total of 24 hips) with DDH undergoing CPO between February 2006 and March 2014 were included in this study. The normal group was defined as the normal side in patients with unilateral osteonecrosis of the femoral head (ONFH) and the non-collapsed femoral head side in patients with bilateral ONFH. Pre- and postoperative hip functions were evaluated using the Japanese Orthopedic Association (JOA) hip score. ACA was measured using pre- and postoperative three-dimensional computed tomography (3DCT) and described as a clock using a radar chart. The ACA of the normal group was evaluated in the same manner as that for patients who underwent CPO. The ACA before CPO was compared with the ACA after CPO, the ACA before CPO was compared with that of the normal group and the ACA after CPO was compared with that of the normal group at each location. RESULTS: The mean JOA hip scores improved significantly from 69 preoperatively to 88 postoperatively. The superior, posterior, and anterior ACA after CPO significantly increased and the inferior ACA decreased compared with ACA before CPO. The superior, posterior, and anterior ACA before CPO were significantly smaller than ACA in the normal group. The ACA after CPO were similar to the normal group. CONCLUSIONS: CPO improved the anterosuperior coverage of the femoral head but reduced its inferior coverage. The radar chart could visualize acetabulum full circumference and was useful for three-dimensional pre-postoperative evaluation.

Embolization followed by resection of the heterotopic hip joint ossification with spinal cord injury.

BACKGROUND: Heterotopic ossification of large joints, such as knees and hips, has been reported after spinal cord injury, possibly leading to decreased activity of daily living due to a limited range of motion of the affected joint. Therefore, heterotopic ossification resection is performed to improve the range of motion, but it might cause massive bleeding as a complication. METHODS: In this case, the patient had a history of spinal cord injury and developed heterotopic ossification after the left hip injury. He had left hip ankylosis and could not transfer to a wheelchair by himself; therefore, heterotopic ossification resection was planned. On conducting contrast-enhanced computed tomography, the supplying arteries extending to the heterotopic ossification could be identified. A day before the surgery, embolization of the branches by interventional radiology was performed. RESULTS: Heterotopic ossification resection was performed with an 820-ml blood loss. Postoperative rehabilitation was continued, and range of motion continued to improve without heterotopic ossification recurrence 2 years post-surgery. CONCLUSIONS: The combination of preoperative contrast-enhanced computed tomography and embolization was useful in treating heterotopic ossification.

Accuracy of Acetabular Cup Placement During Total Hip Arthroplasty in Supine Position Using a Pelvic Rotation Correction Device.

Background: Accurate cup placement during total hip arthroplasty (THA) is difficult because the intraoperative pelvic position changes even in supine patient position. We developed a device known as HipPointer; it corrects pelvic rotation and creates a functional pelvic plane as a reference. The aim of this study was to determine the device placement accuracy and investigate causes of error. Material and methods: HipPointer was used for cup placement in 353 hips of 308 patients who underwent direct-anterior-approach THA in supine position. The mean age at surgery and body mass index were 63.9 (17-90) years and 24.9 (16.6-42.0) kg/m2, respectively. The mean observation period was 40.5 (12-73) months. To investigate the accuracy of HipPointer, preoperative planning and postoperative cup placement angles relative to the functional pelvic plane were evaluated using a three-dimensional analysis software, and absolute errors were determined. Results: The means ± standard deviations of radiographic inclination (RI) and radiographic anteversion (RA) were 40.2 ± 3.0° and 15.8 ± 3.6°, respectively. The absolute errors of RI and RA were 2.2 ± 2.0° and 2.7 ± 2.3°, respectively. The ratio of the cup placement angle for which both RI and RA are ≤10° in the target zone was 99% (350/353 hips), and the ratio of the absolute errors for which both RI and RA are ≤5° was 80.4% (284/353 hips). Conclusions: HipPointer is simple in structure, easy to use, and useful for direct-anterior-approach THA in supine position. It provides good cup placement accuracy.

Extra-structural elements in the RNA recognition motif in archaeal Pop5 play a crucial role in the activation of RNase P RNA from Pyrococcus horikoshii OT3.

Ribonuclease P (RNase P) is a ribonucleoprotein complex essential for the processing of 5' leader sequences of precursor tRNAs (pre-tRNA). PhoPop5 is an archaeal homolog of human RNase P protein hPop5 involved in the activation of RNase P RNA (PhopRNA) in the hyperthermophilic archaeon Pyrococcus horikoshii, probably by promoting RNA annealing (AN) and RNA strand displacement (SD). Although PhoPop5 folds into the RNA recognition motif (RRM), it is distinct from the typical RRM in that it has an insertion of α-helix (α2) between α1 and ß2. Biochemical and structural data have shown that the dimerization of PhoPop5 through the loop between α1 and α2 is required for the activation of PhopRNA. In addition, PhoPop5 has additional helices (α4 and α5) at the C-terminus, which pack against one face of the ß-sheet. In this study, we examined the contribution of the C-terminal helices to the activation of PhopRNA using mutation analyses. Reconstitution experiments and fluorescence resonance energy transfer (FRET)-based assays indicated that deletion of the C-terminal helices α4 and α5 significantly influenced on the pre-tRNA cleavage activity and abolished AN and SD activities, while that of α5 had little effect on these activities. Moreover, the FRET assay showed that deletion of the loop between α1 and α2 had no influence on the AN and SD activity. Further mutational analyses suggested that basic residues at α4 are involved in interaction with PhopRNA, while hydrophobic residues at α4 participate in interaction with hydrophobic residues at the ß-sheet, thereby stabilizing an appropriate orientation of the helix α4. Together, these results indicate that extra-structural elements in the RRM in PhoPop5 play a crucial role in the activation of PhopRNA.

A distinct binding mode of archaeal ribonuclease P proteins to RNA.

The ribonuclease P (RNase P) in the hyperthermophilic archaeon Pyrococcus horikoshii comprises RNA (PhopRNA) and five proteins. We analyzed the RNA binding mode of the protein, using a pair of complementary fluorescence-labeled oligoribonucleotides. Fluorescence resonance energy transfer (FRET)-based assays suggested that the RNase P proteins assist PhopRNA in attaining a functionally active conformation via a distinct mode of binding.

Effect of Quinapril on the Circadian Blood Pressure Pattern Evaluated by Periodic Analysis of Covariance.

The effects of quinapril on casual blood pressure (BP) and circadian variations in 24-h blood pressure (24ABPM) were studied in patients with essential hypertension. Twenty-six patients were enrolled in the study (mean age 59 plus minus 11 years). After a 4-week washout period, patients, were treated with quinapril 5 mg, 10 mg, or 20 mg once a day until casual blood pressures become optimal within 8--10 weeks. The 24ABPM was performed before and after treatment at 30-min intervals using an ABPM-630 in patients during usual daily activities on the work days. Measured BP was fitted to a periodic regression curve with 24-h and 12-h harmonics. Quinapril significantly decreased casual blood pressure but had no effect on pulse rate. It exhibited an excellent antihypertensive effect throughout 24 h; this effect, however, was stronger during the day than at night, resulting in no excessive nocturnal hypotension. The level of the periodic regression curves for systolic and diastolic blood pressures was significantly decreased following treatment but that of the pulse rate was not affected by this drug. The drug caused changes in the pattern of the periodic regression curve for blood pressure and pulse rate. This was attributed to the more prominent antihypertensive effect of quinapril in the afternoon and evening. To evaluate the efficacy of this drug semiquantitatively, the hyperbaric indices were compared before and after the treatment, and those indices for both systolic and diastolic blood pressures were significantly decreased. Adverse effects occurred in four patients (15.4%), all of which were mild and thought to be clinically insignificant. It was concluded that quinapril, 5--20 mg day(minus sign1), was considered to be useful for patients with mild to moderate essential hypertension.