Distinguishing constitutional from acquired bone marrow failure in the hematology clinic

Distinguishing constitutional from immune bone marrow failure (BMF) has important clinical implications. However, the diagnosis is not always straightforward, and immune aplastic anemia, the commonest BMF, is a diagnosis of exclusion. In this review, we discuss a general approach to the evaluation of BMF, focusing on clinical presentations particular to immune and various constitutional disorders as well as the interpretation of bone marrow histology, flow cytometry, and karyotyping. Additionally, we examine the role of specialized testing in both immune and inherited BMF, and discuss genetic testing, both its role in patient evaluation and interpretation of results.     

Periacetabular bone changes after uncemented total hip arthroplasty evaluated by quantitative computed tomography

Background?There are few dual X-ray absorptiometry (DXA) studies on periacetabular bone density changes after cup implantation. This study was designed to analyze the load-transfer mechanism and stress pattern of periacetabular cortical and cancellous bone after implantation of a ihemispherical titanium alloy press-fit cup with alumina-alumina pairing in vivo. We introduced a novel method of computed tomography (CT)-assisted osteodensitometry.

Method?We investigated 26 hips (26 patients) with osteoarthritis using conventional sequential CT examinations performed within the first 10 days after implantation, and after a mean period of 1.1 years postoperatively. Bone density of full, cancellous and cortical bone (mgCaHA/mL) was measured.

Results?At the time of follow-up, the mean bone density values of the cortical bone cranial to the cup increased by 3.6% (p = 0.03) while the cancellous bone density decreased by 18%. Cancellous bone loss was greater in the region ventral to the cup (–35%) than in the dorsal region (–30%). Cortical bone density decreased ventral to the cup (–6.4%). All these changes were statistically significant. The bone density changes in the dorsal cortical region were not significant.

Interpretation?The method presented is an excellent tool for detailed measurement of bone density changes around the cup after total hip arthroplasty, and allows a thorough assessment of stress shielding phenomena in vivo. The hemispherical titanium alloy press-fit cup is a rigid implant which stress shields cancellous bone and enhances load transfer to the cranial cortical bone. Further investigations will demonstrate the impact these factors have on the long-term results of the implant, and may allow a type-related predictable prognosis of the longevity of the prosthesis.     

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??Objective??To evaluate the clinical effect of maxillary sinus lifting??bone graft??and simultaneously placement of implants in severely atrophic maxillae and the stability of cylindrical implants. Methods??Totally 20 patients with 30 Straumann tissue-level implants were included. After osteotome sinus floor elevation and grafting??implants were inserted. Patients were recalled at 1 and 3-years follow-up. Implant success??resonance frequency analysis??clinical and radiographic outcomes were recorded. Results??At 3-year examination??the implant success rate was 96.7%. The ISQ value was 71.1±4.15??69.6 ± 5.01??68.4 ± 4.34 and 72.8 ± 6.42 at implant insertion??2??4 and 12 weeks after surgery. Modified bleeding index was 0.53 ± 0.40 and 0.61 ± 0.31 at 1 and 3-year examination. Probing depth was??3.21 ± 0.67??mm and??3.45 ± 0.71??mm at 1 and 3-year examination. Modified plaque index was 0.48 ± 0.44 and 0.52 ± 0.51 at 1 and 3-year examination. No significant difference was found between two examinations. Marginal bone loss increased from ??1.16 ± 0.27??mm at 1-year follow-up to ??1.45 ± 0.39?? mm at 3-year follow-up??the difference reached statistically significant??P < 0.05??. Implant apex height decreased from ??2.05 ± 0.43??mm at baseline to ??1.85 ± 0.75??mm at 1-year and ??1.42 ± 0.69??mm at 3-year follow-up??the difference reached statistically significant??P < 0.05??. Conclusion??Maxillary sinus lifting??bone graft??and simultaneously placement of implants could be a predicable treatment option in severely atrophic maxilla. In addition??cylindrical implants could achieve enough stability during the healing phrase. High success rate could be achieved in the short term.     

Bone loss associated with use of antiepileptic drugs

Importance of the field: Epilepsy is a neurological disorder associated with several comorbidities, one of them being reduced bone health. As the bone loss most often is insidious and asymptomatic, they are usually not recognized, and thus untreated. The key message of this paper is to make clinicians aware of the problem.

Areas covered in this review: This article reviews data from basic and clinical studies of bone loss associated with usage of antiepileptic drugs (AEDs) within the last 4 decades.

What the reader will gain: The reader will learn that there is accumulating evidence of biochemical abnormalities indicating a disturbed bone metabolism, a decreased bone density and a 2 – 6 times increased risk of fractures among those with epilepsy compared to the general population. These findings most likely have many causes, both internal and external, but long-term use of AEDs seems to play an important role. Enzyme-inducing drugs, such as phenytoin, phenobarbital and carbamazepine, but also the enzyme inhibitor valproate, appear to have bone-depleting properties. Reduced bone density may be detected during the first 1 – 5 years of treatment. Although many theories have been launched, the exact mechanisms by which the the drugs affect bone architecture are not fully understood.

Take home message: We recommend clinicians to promote osteoprotective behavior among their epilepsy patients; that is, sunlight exposure and weight-bearing exercise as well as avoidance of risk factors such as bone-depleting drugs other than AEDs, smoking and heavy alcohol consumption. Enzyme inducing drugs should be avoided, if possible. Bone mineral density screening should be assessed on an individual basis, taking risk factors for bone loss into account. All patients taking AEDs on long-term basis ought to have adequate amounts of dietary calcium and vitamin D, and those who have developed bone loss should in addition be given specific antiosteoporotic treatment.     

Initial Implant Stability Predicts Migration But Not Failure in Cementless Acetabular Revision with Bone Grafting

Host bone contact of less than 50% is perceived but not proven to cause migration and loosening after actetabular revision. A prospective analysis of cementless acetabular revision cases with impaction grafting was performed to determine if this was an independent risk factor for these events. Sixty-two hips in 54 patients were assessed at a mean follow-up of 84.5 months (range 61–112) yielding a probability of 94.6% of retaining the acetabular component using revision for aseptic loosening as the end point. No single factor was independently causative for loosening, although Type III fixation was associated with migration (p = 0.0159); subanalysis suggested that achieving host–bone contact in at least part of the dome and posterior column is important.     

Nephrotoxicity in isoxazolylpenicillin prophylaxis in hip surgery

In 789 courses of antibiotic prophylaxis in hip arthroplasty surgery, either dicloxacillin (Diclocil®) or cloxacillin (Ekvacillin®) was used during two different time periods. The surgical methods, anesthesia, preoperative and postoperative care of the patients, and laboratory procedures were the same all the time. Changes in creatinine values were used as a method for evaluating the impact on renal function. When using dicloxacillin, a pathologic increase of creatinine was noted in 12 and 13 percent by two different calculation methods. Sixteen patients (4.2 percent) had a severe creatinine increase during the first postoperative week after dicloxacillin prophylaxis, requiring dialysis in 2 patients. Cloxacillin had only a marginal impact on renal function. Patients above aged 70 years were more vulnerable as regards renal function than younger persons, and the impairment was slightly dose related in all ages. In the dicloxacillin group, preoperative use of antiphlogistic drugs was correlated with reduced postoperative renal function.