Surgical treatment of Hip PJI by resection of the infected implants and tissue and placement of a “spacer” which elutes antibiotic via antibiotic loaded cement is an accepted treatment option. There is some controversy over whether this “spacer” should be articulating or static. Proponents of the articulating option argue that there is improved function and maintenance of the soft tissue envelop. Critics have suggested that additional biomaterials may compromise eradication of infection. This study compares our results of the 2 treatment options.

A review of our institutional PJI database between 2016 and 2021 identified 87 patients who were treated with resection arthroplasty for unilateral total hip PJI. The cohort was analyzed for demographics and type for surgery, as well as medical comorbidities, survivorship, and treatment success.

44 patients were female, the mean age of all patients was 62. 44 patients were treated with Articulating apacers, and 43 patients treated with static spacers. There was no significant difference between ASA or Elixhauser score, and no significant difference between mortality or treatment failure.

This study did not show any difference between the patients who receive static spacers, from those who received articulating spacers, and deomstrated similar treatment success rates. From this data there does not appear to be any difference in success rates between those patients that were treated with static spacers and those that were treated with articulating spacers.

Aims

Osteoarthritis (OA) is prevalent among the elderly and incurable. Intra-articular parathyroid hormone (PTH) ameliorated OA in papain-induced and anterior cruciate ligament transection-induced OA models; therefore, we hypothesized that PTH improved OA in a preclinical age-related OA model.

Echocardiography is commonly used in hip fracture patients to evaluate perioperative cardiac risk and identify cardiac abnormalities. However, echocardiography that delays surgical repair may be harmful. The objective of this study was to compare mortality, surgical wait times, length of stay (LOS), and health care costs for similar hip fracture patients managed with and without preoperative echocardiograms.

A population based, retrospective cohort study of all hip fracture patients (>age 45) in Ontario, Canada was conducted. The primary exposure was pre-operative echocardiography (between hospital admission and surgery). Patients receiving preoperative echocardiograms were matched to those without using a propensity score incorporating patient demographic information, comorbidity status, and provider information. Mortality rates, surgical wait times, post-operative length of stay (LOS), and medical costs (expressed as 2013$ CAN) up to 1-year post-operatively were assessed after matching.

There were 2354 (∼5.6%) of 42,230 eligible hip fracture patients that received a preoperative echocardiogram during the study period. After successfully matching 2298 (∼97.6%) patients, echocardiography was associated with significant increases in mortality at 90 days (20.1% vs. 16.8%, p=0.004) and 1 year (32.9% vs. 27.8%, p < 0 .001), but not 30-days (11.4% vs. 9.8%, p=0.084). Patients with echocardiography also had an increased (mean ± SD) delay (in hours) from presentation to surgery (68.80 ± 44.23 hours vs. 39.69 ± 27.09 hours, p < 0 .001) and only 38.1% of patients had surgery within 48 hours. Total LOS (in days) (mean 19.49 ± 25.39 days vs. 15.94 ± 22.48 days, p < 0 .001) and total healthcare costs at 1 year (mean: $51,714.69 ± 54,675.28 vs. $41,861.47 ± 50,854.12, p < 0 .001) were also increased. There was wide variability in echocardiography ordering practice in Ontario, with a range of 0% to 22.97% of hip fracture patients undergoing preoperative echocardiography at different hospital sites.

Preoperative echocardiography for hip fracture patients is associated with increased postoperative mortality. It is also associated with increased surgical delay, post-operative LOS, and total health care costs at 1 year. Echocardiography should be considered an urgent test when ordered to prevent additional surgical delay, and further research is necessary to clarify indications for this common preoperative investigation.

Echocardiography is commonly used in hip fracture patients to evaluate perioperative cardiac risk and identify cardiac abnormalities. However, echocardiography that delays surgical repair may be harmful. The objective of this study was to compare mortality, surgical wait times, length of stay (LOS), and health care costs for similar hip fracture patients managed with and without preoperative echocardiography.

A population based, retrospective cohort study of all hip fracture patients (>age 45) in Ontario, Canada was conducted. The primary exposure was pre-operative echocardiography (between hospital admission and surgery). Patients receiving preoperative echocardiography were matched to those without using a propensity score incorporating patient demographic information, comorbidity status, and provider information. Mortality rates, surgical wait times, post-operative length of stay (LOS), and medical costs (expressed as 2013$ CAN) up to one year post-operatively were assessed after matching.

There were 2354 (∼5.6%) of 42,230 eligible hip fracture patients that received preoperative echocardiograghy during the study period. After successfully matching 2298 (∼97.6%) patients, echocardiography was associated with significant increases in mortality at 90 days (20.1% vs. 16.8%, p=0.004) and one year (32.9% vs. 27.8%, p < 0 .001), but not 30-days (11.4% vs. 9.8%, p=0.084). Patients with echocardiography also had an increased (mean ± SD) delay (in hours) from presentation to surgery (68.80 ± 44.23 hours vs. 39.69 ± 27.09 hours, p < 0 .001) and only 38.1% of patients had surgery within 48 hours. Total LOS (in days) (mean 19.49 ± 25.39 days vs. 15.94 ± 22.48 days, p < 0 .001) and total healthcare costs at one year (mean: $51,714.69 ± 54,675.28 vs. $41,861.47 ± 50,854.12, p < 0 .001) were also increased. There was wide variability in echocardiography ordering practice in Ontario, with a range of 0% to 22.97% of hip fracture patients undergoing preoperative echocardiography at different hospital sites.

Preoperative echocardiography for hip fracture patients is associated with increased postoperative mortality. It is also associated with increased surgical delay, post-operative LOS, and total health care costs at one year. Echocardiography should be considered an urgent test when ordered to prevent additional surgical delay, and further research is necessary to clarify indications for this common preoperative investigation.

The process of obtaining informed consent is an important and complex pursuit, especially within a paediatric setting. Medical governing bodies have stated that the role of the trainee surgeon must be explained to patients and their families during the consent process. Despite this, attitudes and practices of surgeons and their trainees regarding disclosure of the trainee's participation during the consent process has not been reported in the paediatric setting.

Nineteen face-to-face interviews were conducted with surgical trainees and staff surgeons at a tertiary level paediatric hospital in Toronto, Canada. These were transcribed and subsequently thematically coded by three reviewers.

Five main themes were identified from the interviews. 1) Surgeons do not consistently disclose the role of surgical trainees to parents. 2) Surgical trainees are purposefully vague in disclosing their role during the consent discussion without being misleading. 3) Surgeons and surgical trainees believe parents do not fully understand the specific role of surgical trainees. 4) Graduated responsibility is an important aspect of training surgeons. 5) Surgeons feel a responsibility towards both their patients and their trainees. Surgeons don't explicitly inform patients about the involvement of trainees, believing there is a lack of understanding of the training process. Trainee perspectives reflect this, with the view that families are aware of their participation but likely underestimate their role, and suggest that information is kept purposely vague to reduce anxiety.

The majority of surgeons and surgical trainees do not voluntarily disclose the degree of trainee participation in surgery during the informed consent discussion with parents. An open and honest discussion should occur, allowing for parents to make an informed decision regarding their child's care. Further patient education regarding trainees' roles would help develop a more thorough and patient centred informed consent process.

Aims

As the peak of the COVID-19 pandemic passes, the challenge shifts to safe resumption of routine medical services, including elective orthopaedic surgery. Protocols including pre-operative self-isolation, COVID-19 testing, and surgery at a non-COVID-19 site have been developed to minimize risk of transmission. Despite this, it is likely that many patients will want to delay surgery for fear of contracting COVID-19. The aim of this study is to identify the number of patients who still want to proceed with planned elective orthopaedic surgery in this current environment.

Aims

Graft infection following anterior cruciate ligament reconstruction (ACLR) may lead to septic arthritis requiring multiple irrigation and debridement procedures, staged revision operations, and prolonged courses of antibiotics. To our knowledge, there are no previous studies reporting on how gentamicin pre-soaking of hamstring grafts influences infection rates following ACLR. We set out to examine this in our study accordingly.

The process of gaining informed consent can be a complex and much debated pursuit, especially within a paediatric setting. The role of the trainee surgeon and its explanation to children and their families prior to an operation has not been explored from the resident surgeons' point of view. Ten face-to-face interviews were conducted with orthopaedic surgery trainees at a tertiary level paediatric hospital in Toronto, Canada. These were transcribed and subsequently thematically coded by 3 reviewers. Three main themes were identified from the interviews. 1) Surgical trainees feel their level of participation and autonomy gradually increases dependent on their observed skills and level of training. 2) Trainees feel the consent process is adequate but acknowledge it is often purposely vague with regards to their intra-operative involvement as this is often unpredictable and it avoids patient/family anxiety. 3) Trainees believe families are aware of their participation however most likely underestimate their role during operations. Trainees in surgical specialties believe their level of autonomy is variable dependent on a number of factors and that this impacts on the ability to be more specific when gaining informed consent. This must be balanced with a family's right to an appropriate understanding of their child's operation and who is performing it. It may be that further patient education regarding trainees and their role in operations would help develop a more thorough and patient centred informed consent process.

Introduction

Acetabular dysplasia cause hip joint osteoarthritis(OA) by change hip mechanism. However, to our best knowledge, no studies have been published using prospectively collected data from asymptomatic young age volunteers, precise radiographic method. The purpose of this study is to evaluate the prevalence of hip dysplasia in asymptomatic Korean population as one of the most important risk factor of hip OA.

It has been reported that the total steroid dose and acute rejection episodes after organ transplantation is one of the risk factors for the development of osteonecrosis of the femoral head (ONFH), and ONFH in steroid-iduced subgroup may progress more aggressively to femoral head collapse requiring total hip arthroplasty. Despite inherent medical co-morbidities of solid organ transplantation patients, most authors recently have reported successful outcomes of THAs in those patients. But there are few comparative studies on the outcome of THAs for ONFH after different organ transplantations. The purpose of this study was to evaluate and compare a single tertiary referral institution's experience of performing primary THAs in kidney transplantation (KT) and liver transplantation (LT) patients with specific focus on the total steroid dose, clinical outcomes, and relationship between ONFH and absence or presence of acute rejection (AR).

Between 1999 and 2010, 4,713 patients underwent organ transplantations (1,957 KT and 2,756 LT) and AR was occurred in 969 patients (20.6%) after transplantation. Among these patients, 131 patients (191 hips) underwent THA for ONFH, and they were retrospectively reviewed. In KT groups, there were 57 men and 36 women with a mean age of 43.7 years. In LT groups, there were 26 men and 13 women with a mean age of 50.4 years. We investigated the dose of steroid administration on both groups, the time period from transplantation to THA, Harris hips score (HHS), visual analogue scale (VAS) and complications. The mean follow up period was 8.1 years (range, 5 to 14 years).

One-hundred and thirty-one (2.8%) patients [93 KT and 38 LT] underwent THA after transplantation. The total steroid dose after transplantations was significantly higher in KT group (10,420 mg) than that in LT group (4,567 mg), but the total steroid dose in the first 2 weeks after transplantation was significantly higher in LT group (3,478 mg) than that in KT group (2,564 mg). Twenty-three (2.4%) patients (19 KT and 4 LT) who underwent THA had an episode of AR. In LT group, the total steroid dose in AR groups was significantly higher than that in non-AR groups, whereas in KT group, there was no significant difference of the total steroid dose between AR group and non-AR group. The rate of THAs for ONFH was similar in both groups (2.4% in AR group, 2.9% in non-AR group). The mean time period from transplantation to THA was 986 days for KT and 1,649 days for LT patients. Both groups showed satisfactory HHS and VAS at final follow up, revealed no differences between the groups.

The rate of THAs for ONFH was three times higher in KT patients than that in LT patients, but it was similar in both AR group and non-AR group. The total steroid dose was also higher in KT patients compared to LT patients. The clinical outcomes of THA were satisfactory with few complications in both KT and LT patients. Therefore, THAs seems to be a good option for the patients with symptomatic steroid-induced ONFH after KT and LT.

Aim

Chronic osteomyelitis often requires surgical debridement and local antibiotic treatment. Disadvantages of PMMA carriers include low dose release and the requirement of surgical removal in the case of PMMA-beads. Synthetic nanocrystalline calcium phosphate (nCP) materials, which mimic the chemical structure of the mineral composition of bone, have been well accepted as bone grafting materials due to their consistent osteoconductivity, ease of use, and mechanical properties. Such a material which remodels into native bone is a much more attractive option. The aim of this study is to investigate the release of gentamicin from CaP in vitro and in vivo when implanted in a rabbit femoral condyle defect.

Total Hip Arthroplasty (THA) has been more frequently performed for relatively young patients with osteonecrosis of the femoral head in Korea. Moreover, squatting and sitting with crossed legs are more common in Asian cultures than in Western cultures. Wear debris generated by conventional metal-on-PE articulations has been giving rise to extensive osteolysis. Due to these characteristics, higher incidence of pelvic osteolysis was observed after THA in Korea. As a result, interest in alternative bearings such as ceramic-on-ceramic bearing has been increased. Furthermore, the patients who require revision THA are still young in Korea. With this point of view, an application of ceramic-on-ceramic bearing throughout revision THA seems to be reasonable. The clinical and radiographical outcomes after revision THA with use of third generation ceramic-on-ceramic bearing in Korean patients were evaluated.

Materials and Methods: We have analyzed 42 hips (37 patients; 17 men and 20 women), in whom revision THAs were performed using cementless cups with ceramic-on-ceramic bearing (Biolox Forte; CeramTec, Plochingen, Germany). They underwent THA at a single institution between February 2000 and December 2004, and were consecutively enrolled in this study. Their mean age was 48.8 years (32 – 59 years), and their mean weight was 61.5 ± 5.8 kg (50 – 72 kg) and BMI was 23.8. The mean interval from primary to revision THA was 9.5 ± 3.2 years (3.3 – 16.1 years). The preoperative diagnoses for primary THA were osteonecrosis of the femoral head in 31 hips, neglected femoral neck fracture in 3, rheumatoid arthritis in 2, degenerative osteoarthritis in 2, pyogenic arthritis in 2, tuberculosis arthritis in 1, and fused hip in 1. Dissociation of PE liner was observed in 21 hips (50%). For acetabular cup revision, Trilogy ceramic acetabular cups (Zimmer, Warsaw, IN) were used in 22 hips, EP-FIT plus cups (Plus Orthopedics, Rotkreuz, Switzerland) in 14 hips, and Duraloc Option Ceramic cups (DePuy, Warsaw, IN) in 6 hips. Stems were revised in all hips. The follow-up protocol included radiographic and clinical evaluations, and the mean duration of follow-up monitoring after revision THA was 5.4 ± 1.7 years (3.2 – 8.0 years). At final follow-up examination, clinical outcomes including Harris Hip Score and complications were assessed. All changes in inclination were documented radiographically. The presence of radiolucent lines, vertical or horizontal migration of acetabular cup (> 2 mm), and osteolysis were also evaluated.

Results: At final follow-up evaluation after revision, the average Harris Hip Score was 91.3. There were no revised hips during follow-up period. In 6 hips (14.3%), minor complications were observed: 3 heterotopic ossifications, 2 dislocations, 1 infection. No revision was necessary for the treatment of these complications. There were no hips with radiolucent lines, vertical or horizontal acetabular cup migration or osteolysis during the follow-up period. In 21 hips with bone graft, incorporation of bone graft was observed radiographically at final follow-up examination.

Conclusions: Our data showed that clinical and radiographical outcomes after revision THA using third generation ceramic-on-ceramic bearing were favorable. Revision THA with the use of ceramic-on-ceramic bearing surfaces can be preferentially considered especially in young patients. Further studies with long-term follow-up data are warranted.

Although the clinical manifestation of ONFH is well summarized as forms of various stages, its etiology, natural history or epidemiology has not been clearly elucidated yet. With this study, we wanted to find out the estimated annual incidence, epidemiologic characteristics and the effect of known risk factors of ONFH. Therefore we can understand the disease better to provide optimal management to the patients.

Among 133 189 patients who diagnosed as osteonecrosis of femoral head (ONFH) in database of national health insurance system in Korea from 2002 to 2006, three hundreds an eighty-two samples were randomly extracted with 5% error range in 95% confidence interval. With a structured worksheet, medical records and radiographs of each sample were reviewed at corresponding clinic or hospital by authors and trained orthopedic surgeons. With these data, we calculated the prevalence and associated risk factors.

The mean number of annual requests was 23 466. Among 382 samples, two hundreds and seventy-four were confirmed to have ONFH. Diagnostic accuracy was 71.7 %. Diagnosis was more accurate when the patient was male or hospitalized. After the logistic regression analysis, calculated diagnostic accuracy during 2002 and 2006 was 60.3% (51 823/85 987). The annual predicted number of cases of ONFH during this period was 14 103. It corresponds to 28.91 patients per 100 000 populations. Alcohol abuse was noted in 45% and 22% was related to use of steroid. 37% showed bilateral involvement. Bone graft procedures in any kind was the most frequently performed joint preserving procedure.

With this, the first epidemiologic study for ONFH in Korea, we estimated nationwide annual prevalence of ONFH as 28.91 per 100,000 populations during 2002 and 2006. There is an absolute male predominance. Alcohol abuse is the most frequent risk factors. We believe that this result can serve as a baseline data for understanding the epidemiology, clinical characteristics and treatment of ONFH.

Beta–tricalciumphosphate(β-TCP)coatinglayerisknown to be resorbed much faster than hydroxyapatite(HA), however, there has been few reports explaining the exact mechanism until now. Therefore, we investigated whether the resorption mechanisms of these two compounds are same, if not, what is the difference.

Eighty titanium discs with 12mm in diameter and 2mm in thickness were coated with HA(n=40) or β-TCP(n=40) by dip and spin coating method. In each group, the specimens were divided into 2 subgroups respectively; Dissolution (D, n=20) group and Osteoclast culture (C, n=20) group. The coated discs in D group were immersed in the cell culture media for 5 days, whereas, in C group, osteoclast-like cells (5×103 cells/500μ), which were isolated form human giant cell tumor, were seeded on the specimens and cultured for 5 days. Cultured cells were defined as osteoclast by the determination of osteoclast marker (tartrate-resistant acid phosphatase, TRAP). After immersion or osteoclast culture, the dissolution characteristics of coating surface were observed using light microscope (LM) and scanning electron microscope (SEM). And the area fraction of resorption lacunae formed by osteoclast was analyzed by image analysis to evaluate the activity of osteoclastic degradation.

After 5 days of dissolution, there were much more cracks and denuded areas in β-TCP coating compared to HA coating. In C group, the osteoclasts covering the coating layer were identified on LM and SEM images. Mean area fraction of resorption lacunae in HA-C group was 11.62%, which was significantly higher than that of 0.73% of β-TCP-C group (p=0.001).

We conclude that the resorption mechanism of HA and β-TCP coating layers was different each other in vitro study. The coated β-TCP was degraded mainly by dissolution and also tended to be separated from implant, on the other hand, the HA coating layer was resorbed by osteoclastic activity

Introduction: Ethanol is one of risk factors associated with osteonecrosis, it has been demonstrated that ethanol induces adipogenesis, decreases osteogenesis in bone marrow stroma cells and produces intracellular lipid deposits, resulting in the death of osteocytes.

Materials and Methods: In this approach, we isolated human bone marrow stroma cells and triggered for different differentiations.

Results: These cells could be induced for osteogenesis, adipogenesis, and chondrogenesis. We also evaluated cell surface markers of isolated human bone marrow stromal cells that were found to express CD29, CD49d, CD62 CD90, CD105/SH2, SH3, CD133, and CD166, but not CD31, CD34, CD45, or CD56.

Discussion: We demonstrated that ethanol decreases the expression of osteogenic genes, but increases adipogenic genes expressions. Moreover, we found that ethanol decreases the beta-catenin-dependent canonical Wnt signaling pathway related gene expressions, including Wnt 3a and LRP5 genes. Interestingly, ethanol also diminishes the intra-nuclear translocation of β-catenin in human bone marrow stromal cells. Therefore, these results indicate that ethanol might decrease osteogenic gene expressions through Wnt signaling pathway.

Introduction: The purpose of this study was 1) to evaluate the relationship between osteonecrosis of the femoral head (ONFH) and alcohol abuse, 2) to define the patterns of the alcohol intake in the development of ONFH, and 3) to define the risk factors in alcohol induced ONFH.

Materials and Methods: Two hundred and fifty patients (333 hips) with ONFH diagnosed on the basis of histopathologic findings after total hip arthroplasty were analyzed. Among these patients, 169 patients who had a history of alcohol and idiopathic ONFH were selected as the case group. Two controls selected by a review of the orthopedic patient records were matched to each case (338 controls). From each patient and control, a detailed history of alcohol drinking, cigarette smoking, and herb medicine, weight, height, sGOT, sGPT and total cholesterol levels were obtained and analyzed. Statistical analysis was performed using the Generalized Linear Model including Chi-Square test, Fisher’s exact test, ANOVA, and T-test. The adjusted relative odds ratio and 95 percent confidence interval (CI) were obtained using a conditional logistic regression model.

Results and Discussion: The authors could confirm a direct relationship between alcohol abuse and ONFH. The amount of alcohol intake was more significant than the duration of alcohol intake for the risk of the development of ONFH. The risk factors related with the patterns of alcohol consumption in the development of alcohol induced ONFH are as follows: 1) more than 4 times per week of alcohol intake, 2) more than 90 g of alcohol intake at one time, 3) more than 300 g of weekly alcohol intake, 4) more than 6000 drink-years, 5) no side dishes. The other risk factors are smoking, low body mass index, and abnormal liver function tests.

Introduction: Hyperlipidemia is related to hypercoagulability and hypofibrinolysis, which may cause a tendency to intravascular thrombosis and result in osteonecrosis (ON). Recently PPARs were confirmed to induce adipocyte differentiation, and fatty acids were identified as the transcriptional effectors for PPARs, which may cause the hyperlipidemia and fatty marrow. The aim of this study was to identify whether the adipocytic differentiation was increased in the bone marrow obtained from the femoral head in patients with osteonecrosis.

Materials and Methods: A lipid profile (cholesterol, triglyceride, LDL, and free fatty acid) was performed for patients with osteonecrosis of the femoral head. The PPARγ2 expression was checked as to whether the mesenchymal stem cells differentiate toward adipocytes rather than osteogenic cells. RT-PCRs were completed using the bone marrow stroma cells obtained during THA from 11 patients with osteonecrosis and 9 control patients. As not all of alcoholics and steroid users develop osteonecrosis, genetic differences may relate to susceptibility to the osteonecrosis. Therefore, we determined the polymorphism of the PPARγ2 gene for 34 osteonecrosis patients and 76 controls.

Results: Among 89 cases of osteonecrosis, increased free fatty acid (above 580mg%) was the most frequent finding (40.8%), and triglyceride was the next (29.6%). Cholesterol was increased in only 9.0%. Seven of the osteonecrosis cases (63.6%) and 4 of the control cases (44.4%) expressed PPARγ2. Pro/Ala (C/G) polymorphism was found in seven (20.6%) ON cases and four control cases (5.3%), and Ala/Ala (G/G) polymorphism was found in only 1 case in the control group. The numbers of patients with elevated triglyceride among osteonecrosis were much higher (71.4%) in polymorphism (C/G) than osteonecrosis (21.5%) without polymorphism.

Discussion: In conclusion, hyperlipidemia and higher expression of the PPARγ2 were found in ON, and Pro/Ala PPARγ2 polymorphism was more common in ON.

Introduction: Studies have shown steroidal and non-steroidal anti-inflammatory drugs (NSAIDs) suppress bone remodeling. Previous results have indicated that NSAIDs suppress proliferation and induce cell death in cultured osteoblasts and pluripotent stem cells (D1-cells), suggesting these effects might be one of the mechanisms contributing to their inhibitory effects on bone remodeling in vivo. On the other hand, our previous results indicated that dexamethasone treatment shifts the characteristics of osteogenesis into adipogenesis in D1-cells. However, the influences of NSAID on adipogenesis in pluripotent stem cells have rarely been investigated. In this study, we tested the adipogenesis of D1-cells upon long-term treatment of NSAIDs. NSAID influence on the osteocalcin expressions of D1-cells was also examined.

Materials and Methods: The effects of treatments with indomethacin, ketorolac, diclofenac and piroxicam (10⁻⁵ and 10⁻⁴ M) for 2, 4 6 or 8 days were evaluated. Lipid droplets in cultures were detected by oil red staining. Adipsin and osteocalcin mRNA expressions were examined by RT-PCR.

Results: In this study, 10⁻⁴M of NSAID treatment for 4–8 days induced adipogenesis in D1-cells, while shorter duration and lower concentration did not. Mild adipogenesis also occurred in cultures treated with 10⁻⁵M of indomethacin for 6 or 8 days, revealing the strongest effect among the 4 NSAIDs. Piroxicam revealed less effects on adipogenesis in D1-cells. However, despite 2-days of treatment with 10⁻⁵M indomethacin, NSAIDs did not affect the expression of osteocalcin either at 10⁻⁵–10⁻⁴M or during 2–8 days of treatments.

Conclusion: These results suggest that high dose and long term administration of NSAIDs may induce adipogenesis in pluripotent stem cells.

Introduction: Proton magnetic resonance spectroscopy (¹H MRS) is a powerful non-invasive technique used to identify and quantify chemical compounds. In a recent study, the early histopathologic findings of osteonecrosis showed marrow edema and hemorrhage, and the late findings were fibrous marrow transformation with new bone formation. The purpose of this study was to apply ¹H MRS to the bone marrow of osteonecrosis and bone marrow edema syndrome by measuring the amount of lipid relative to water of the femoral head and greater trochanter.

Materials and Methods: Magnetic Resonance (MR) imaging and MR spectroscopy were performed in twenty-five patients (male: female = 17:8, age = 29–69 years) who were diagnosed with osteonecrosis and bone marrow edema syndrome and compared with three normal control patients. Twenty-three cases were osteonecrosis and two were bone marrow edema syndrome. Ficat stages of osteonecrosis in the femoral heads were 1 patient with stage I, 8 patients with stage II, and 14 patients with stage III disease. Osteonecrosis developed in 14 patients with steroid therapy after kidney transplantation, in 6 alcoholics, and 3 were idiopathic. After routine hip MRI, spectroscopy was obtained from T2 weighted images by the 3-dimensional localization technique. Locations of voxels were the center of the osteonecrotic zone verified by T2-weighted MR images and from the fat marrow in the greater trochanter of femur. The values of the [Lipid/Water] ratios were calculated for all patients.

Results: The average Lipid/Water ratio of the osteonecrotic area was 3.15, those of the greater trochanter was 6.45, compared with 10.28 in the normal control group. The MRS pattern for osteonecrosis could be divided into 4 patterns: A, Lipid/Water > 10 ; B, 3 < Lipid/Water ≤ 10; C, 0.3 ≤ Lipid/Water < 3; and D, Lipid/Water ≤ 0.3. The numbers of cases for each pattern were 1 in A, 6 in B, 10 in C, and 6 in D. Interestingly, in one patient with Ficat stage I osteonecrosis diagnosed by only bone scintigraphy, ¹H MR spectroscopy revealed a much higher lipid/water peak ratio compared to the normal control group. The average Lipid/Water ratio of the bone marrow edema syndrome patients was 0.71.

Discussion: This study revealed the decreasing pattern of lipid content as osteonecrosis progresses, which correlates with histopathologic results. In bone marrow edema syndrome, a reverse pattern to the normal control group was found. Further study is needed for the change of Lipid/Water ratio in early change of osteonecrosis.

Introduction: Our previous study found that glucocorticoids shifted the properties of osteogenesis to adipogenesis in murine marrow stem cells. These effects may be one of the important mechanisms in the pathogenesis of osteonecrosis. Statins prevented these steroid effects. In this study, we investigated the effects of dexamethasone and lovastatin on the expressions of bone morphogenetic protein-2 (BMP2) in the bone marrow stroma cells cultured from osteonecrotic patients.

Materials and Methods: Bone marrow fluid aspiration from iliac crest was performed in osteonecrosis (ON) and non-ON patients after surgical treatment for their hip disorder. The mean age of the patients was 59 years in the ON group and 63 years in the non-ON group. Nucleated stroma cells were isolated from bone marrow fluid by percol separation. The third passage cultures were used for experiments. Drug treatments for cultures included dexamethasone (10⁻⁷M), lovastatin (10⁻⁶ M), and dexamethasone plus lovastatin for 4 days. BMP-2 mRNA expression was evaluated by RT-PCR. Different responses to drugs between the ON group and the non-ON group were compared.

Results: Bone marrow stroma cells of ON patients were found to be more susceptible to the suppressive effect of dexamethasone on BMP2 expression.

Discussion: Lovastatin stimulated the osteogenesis and reversed the steroid suppressive effect in bone marrow stroma cells in non-ON cases. However, this reverse effect was found to be mild in ON cases.