Prevalence Of Avascular Necrosis Research Articles

Avascular Necrosis of Femur (AVNF) in Patients with Sickle Cell Disease: A Systematic Study from India

Introduction: Sickle cell disease (SCD) is one of the most common monogenic disorder world-wide and is a major health burden in India. Limited information is available on the prevalence of avascular necrosis (AVN) in Indian sickle cell patients. The present study focuses on understanding the prevalence of AVN of hip in patients with SCD and its correlation with different biochemical parameters and associated genetic modifiers. Methodology: SCD individuals at steady state with no blood transfusion prior to 3 months were recruited in the study after informed consent by a consecutive sampling for the study at ICMR-Centre for Research Management and Control of Haemoglobinopathies (ICMR-CRMCH), Chandrapur. All the clinical details including history and examination findings were noted. Laboratory evaluation included complete blood count, HPLC analysis, liver function test (LFT) and renal function tests and genetic modifiers including alpha-gene deletion and XMN polymorphisms. MRI and X-ray of both hip joints was performed for diagnosis of AVN. Results: One hundred SCD individuals (44 males: 56 females) were enrolled in the study. The median age of individuals was 18 years (IQR: 13-29 years). Individuals were categorized into three groups based on their ages. Children group (6-12 years): 23years, adolescents group (13-17 years): 23 individuals, and Adults (18-52 years): 54 individuals. Sixty five individuals were on drug hydroxyurea (HU), while remaining 35 were not taking HU. The median dosage of HU was found to be 11.9 mg/kg/day (IQR: 9.17-13.5 mg/kg/day). The current study reports the spectrum of avascular necrosis of femur (AVNF) involving normal, early organ dysfunction to end organ damage as 43/96 (44.8%) FICAT stage 0, 40/96 (41.7%) AVNF stage I/II and 13/96 (13.5%) AVNF III/IV/Total hip anthroplasty (THA). The median age (interquartile range) of Ficat Stage 0, I-II and III-IV was found to be 13 (9-17) years, 24.5 (17.3-31.8) years and 23 (18-34) years respectively. Modified harris hip score for Ficat Stage 0, I-II and III-IV was found to be 84 (68-91), 72 (55.0-86.0) and 70 (38.0-89.5) respectively. The mean ± standard deviation (S.D.) levels of hemoglobin (Hb) and HbF% were 9.7±1.6 gm/dl and 21.2±6.6% respectively. SCD individuals who were on drug HU therapy showed higher levels of Hb and HbF% levels, compared to those without HU therapy (p=0.03). Levels of Hb and hematocrit were positively associated with AVNF progression. HbF levels showed no association with AVNF stages. Levels of alkaline phosphatase (ALP) showed negative association with AVNF stages. Genetic modifiers such as α-thalassemia and Xmn1 polymorphism showed no association with present status of AVNF. Conclusion AVNF is frequent complication of SCD leading to significant morbidity especially in young adults. AVNF was more frequent with higher haematocrit, but did not show correlation with HbF levels, α- gene deletion, XMN polymorphism and HU therapy. More research needs to be focused on prevention of AVN.

Avascular necrosis of bone tissue: Definition, epidemiology, types, risk factors, pathogenesis of the disease. Analytical review of the literature

Avascular necrosis (AN) of bone tissue is a common pathology that affects people of any age, more often young and able-bodied. The disease leads to rapid destruction of the subchondral bone and collapse, followed by the development of secondary osteoarthritis (OA) of the affected joint.The purpose of this review article is to present the accumulated knowledge about the prevalence of AN, the most commonly affected joints, risk factors and pathogenesis of the disease. Since most of the world’s literature sources present knowledge about the individual parts and facts that make up the pathogenesis of AN, this article analyzes all known paths of the development of the disease from the onset of ischemia to collapse and the development of secondary OA and the pathogenesis is presented in chronological order. Based on the results of the article, a definition of the term AN was proposed, and the stages of the disease within the pathogenesis, the most promising for conservative methods of treatment, were identified.

Closed reduction evaluation in dysplastic hip with the Ömeroğlu system in children aged 24 to 36 months.

Closed reduction (CR) as an initial treatment for developmental hip dysplasia of the hip (DDH) in children aged 24 to 36 months is debatable; however, it could have better results than open reduction (OR) or osteotomies, because it is minimally invasive. The purpose of this study was to evaluate the radiological results in children (24-36 months) with DDH initially treated with CR. Initial, subsequent, final anteroposterior pelvic radiological records were retrospectively analyzed. The International Hip Dysplasia Institute was used to classify the initial dislocations. To evaluate the final radiological results after CR (initial treatment) or additional treatment (CR failed), the Ömeroğlu system was used (6 points excellent, 5 good, 4 fair-plus, 3 fair-minus, and ≤2 poor). The degree of acetabular dysplasia was estimated using the initial acetabular index and the final acetabular index, Buchholz-Ogden classification was used to measure avascular necrosis (AVN). A total of 98 radiological records were eligible, including 53 patients (65 hips). Fifteen hips (23.1%) were redislocated, OR with femoral osteotomy and pelvic osteotomy was the preferred surgical treatment 9 (13.8%). The initial acetabular index versus final acetabular index in total population was (38.9º ± 6.8º) and (31.9º ± 6.8º), respectively (t = 6.5, P < .001). The prevalence of AVN was 40%. Overall AVN in OR, femoral osteotomy and pelvic osteotomy were 73.3% versus CR 30%, P = .003. Unsatisfactory results ≤ 4 points on the Ömeroğlu system were observed in hips that required OR with femoral and pelvic osteotomy. Hips with DDH treated with CR initially might had better radiological results than those treated with OR and femoral and pelvic osteotomies. Regular, good, and excellent results, ≥4 points on the Ömeroğlu system, could be estimated in 57% of the cases, in whom CR was successful. AVN is frequently observed in hips with failed CR.

Prevalence of Avascular Necrosis Following Surgical Treatments in Unstable Slipped Capital Femoral Epiphysis (SCFE): A Systematic Review and Meta-Analysis.

The choice of treatment for unstable and severely displaced slipped capital femoral epiphysis (SCFE) is controversial. This meta-analysis was conducted to determine the prevalence of femoral head avascular necrosis (AVN) following various treatments for unstable SCFE. Various databases were searched to identify articles published until 4 February 2022. A random-effects model was used to examine prevalence as well as risk ratios with confidence intervals (CIs) of 95%. Thirty-three articles were analyzed in this study. The pooled prevalences of AVN in pinning in situ, pinning following intentional closed reduction, pinning following unintentional closed reduction, and open reduction via the Parsch method, subcapital osteotomy and the modified Dunn procedure were 18.5%, 23.0%, 27.6%, 9.9%, 18.6% and 19.9%, respectively. The risk of developing AVN in pinning following intentional closed reduction was found to be 1.62 times higher than pinning in situ; however, this result was not significant. The prevalence of AVN in open reduction was lowest when performed via the Parsch method; however, this finding should be interpreted with caution, since the majority of slips so-treated are of mild and moderate types as compared with the subcapital osteotomy and modified Dunn procedures, which are predominantly used to treat severely displaced slips. As the risk ratio between intentional closed reduction and the modified Dunn method showed no significant difference, we believe that the modified Dunn method has the advantage of meticulously preserving periosteal blood flow to the epiphysis, thus minimizing AVN risk. In comparison with intentional closed reduction, the modified Dunn method is used predominantly in cases of severe slips.

Prevalence of and Associations With Avascular Necrosis After Pediatric Sepsis: A Single-Center Retrospective Study.

Avascular necrosis (AVN) is a rare, but serious, complication after sepsis in adults. We sought to determine if sepsis is associated with postillness diagnosis of AVN, as well as potential-associated risk factors for AVN in children with sepsis. Retrospective observational study. Single academic children's hospital. Patients less than 18 years treated for sepsis or suspected bacterial infection from 2011 to 2017. Patients who developed AVN within 3 years after sepsis were compared with patients who developed AVN after suspected bacterial infection and with patients with sepsis who did not develop AVN. None. AVN was determined using International Classification of Diseases, 9th Edition/10th Edition codes and confirmed by chart review. The prevalence of AVN after sepsis was 0.73% (21/2,883) and after suspected bacterial infection was 0.43% (53/12,276; risk difference, 0.30; 95% CI, 0.0-0.63; p = 0.05). Compared with 43 sepsis controls without AVN, AVN in the 21 sepsis cases was associated with being older, having sickle cell disease and malignancy, higher body mass index, unknown source of infection, and low platelet count in the first 7 days of sepsis. Half of sepsis patients were treated with corticosteroids, and higher median cumulative dose of steroids was associated with AVN (23.2 vs 5.4 mg/kg; p < 0.01). Older age at infection (odds ratio [OR], 1.3; 95% CI, 1.1-1.4), malignancy (OR, 8.8; 95% CI, 2.6-32.9), unknown site of infection (OR, 12.7; 95% CI, 3.3-48.6), and minimal platelet count less than 100,000/µL in first 7 days of sepsis (OR, 5.0; 95% CI, 1.6-15.4) were identified as potential risk factors for AVN after sepsis following adjustment for multiple comparisons. Although rare, sepsis was associated with a higher risk of subsequent AVN than suspected bacterial infection in children. Older age, malignancy, unknown site of infection, and minimum platelet count were potential risk factors for AVN after sepsis.

Prevalence of avascular necrosis in idiopathic inflammatory myopathies: a single-centre experience.

To assess the prevalence of avascular necrosis (AVN) in a large cohort of patients with idiopathic inflammatory myopathies (IIM) and define the major associated risk factors. We retrospectively reviewed the electronic medical records of all patients with a definitive diagnosis of IIM enrolled in our registry between 2003 and 2017, and followed until 2020. Pertinent demographic, clinical, serologic and imaging data were collected. A matched group of patients without AVN was then selected for comparison. A total of 1680 patients were diagnosed with IIM. Fifty-one patients developed AVN, with an overall prevalence of 3%. Musculoskeletal MRI was available for 1085 patients and AVN was present in 46 patients (43 lower extremities and 3 upper extremities MRI studies), with a relative prevalence of 4.2%. Most patients with AVN were Caucasian females (57%) with a mean (s.d.) age at diagnosis of 44.5 (12.4) years. Sixty-one percent had DM and 29% had PM. The median time from onset of IIM to diagnosis of AVN was 46 months. The hip joint was most commonly involved in 76% of cases, followed by the knee joint in 15% and shoulder joint in 9%. Some 81% of patients were asymptomatic. Established risk factors for AVN were not found to be associated with the development of AVN in IIM patients. Although mostly asymptomatic and incidental, the overall prevalence of AVN in IIM was 3% and the prevalence by MRI was 4.2%. None of the established risk factors was found to be associated with AVN development.

“Prevalence and Outcome of Avascular Necrosis of the Hip (AVN) Among Young Omani Patients with Sickle Cell Disease”

Background: Sickle cell disease is a common hemaglopinapthy worldwide and in Oman. Avascular necrosis (AVN) of the hip causes significant morbidity to patients with sickle cell disease and has a profound impact on their quality of life. This study aims to identify the prevalence and outcome of AVN among young Omani patients with sickle cell disease. Methods: The is a cross sectional study done in the main tertiary care and referral facility in Oman, Sultan Qaboos University Hospital. Out of 3000 registered patients 85 patients found to have clinical and radiological proven AVN, between June 2017-January 2019. Data obtained included demographics, the affected joint, uni or bilateral), radiological staging by FICAT (MRI), hydroxyurea use, dose and duration as well as laboratory data at time of diagnosis. Results: The prevalence of AVN among SCD Omani children and young adults is 2.8 %. Their age ranges between 5-25 (Mean 14.6 +3.4). Male to female ratio was 1.6:1. Based on FICAT system score, most of the cases (82%) are AVN grade 3 and above at diagnosis. Thirty-six patients (42%) were diagnosed to have stage IV AVN. Regarding the hydroxyurea use, 43 patients (50.6%) were already started on HU before the development of AVN. Their mean duration of HU use was 5.3 years, with an average dose of 15.7 mg/kg/day. Fifteen patients developed AVN and were started on HU as part of their management. The follow up MRI of 4 of them showed improvement of their AVN stage (from 4 to 2). Fifteen patients (17.6%) underwent joint replacement because of chronic pain and disability and almost half of them (7 patients) were on hydroxyurea. Conclusion: Prevalence of AVN in young patients with SCD in the main tertiary care referral facility in Oman is 2.8% which is less than the internationally reported. Patients are diagnosed at later stages (3 and above) indicating a possibility of underdiagnosis of asymptomatic stage one and 2 patients. Hydroxyurea use has improved the severity of the AVN in few patients. Disclosures Al-Khabori: SOBI: Honoraria; AstraZeneca: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees; Shire (Takeda): Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; NovoNardisk: Membership on an entity's Board of Directors or advisory committees. Wali:Sultan Qaboos University Hospital: Employment.

PREVALENCE OF ASYMPTOMATIC AVASCULAR NECROSIS OF THE HIP IN PATIENTS WITH KIDNEY TRANSPLANTATION

Abstract Introduction: Kidney transplant is one of the treatments in patients with ESRD (end stage renal disease) that increases the quality of life in patients. Following kidney transplant, patients need glucocorticoid and immunosuppressant drugs. These drugs put patients in risk of hip avascular necrosis. The purpose of this study was to evaluate the prevalence of asymptomatic avascular necrosis of the hip in patients with kidney transplantation. Methods: This prospective descriptive cross-sectional study was conducted on all patients referred to the Shahid Mohammedi Hospital, Bandar Abbas, Iran, who had a kidney transplant at least six month before our study. All patients’ information was collected with a questionnaire consisting of demographic information including age, sex, weight, height, history of hemodialysis, history of peritoneal dialysis, history of smoking, alcohol intake, history of prednisolone and the main variable data of the disease, including the causes of ESRD such as diabetes, hypertension and diabetes combined, polycystic kidney disease, IgA nephropathy reflux disease, focal segmental glomerulonephritis and time elapsed after the transplant. Magnetic resonance imaging (MRI) was used for the detection of avascular necrosis. Diagnosis of avascular necrosis was confirmed by two separate radiologists. Data was analyzed using IBM SPSS 21.0 software. Results: In this study, 83 patients were studied. Among these patients, 45 (54.2%) were male and 38 (45.8%) were female. The average age of the subjects was 41.29 ± 13.72 years. Demographic variables were similar in two groups. There was no relation among the vertebrae and overall results densitometry with avascular necrosis (p>0.05). Based on this chart, prevalence of avascular necrosis in patients with osteoporotic hip based on densitometry, was significantly more than other people (p = 0.008). Conclusion: According to results, prevalence of femoral head avascular necrosis is not higher in patients after transplant and it has no significant relation to age, sex, BMI, time passed after transplant, CMV infection, hospitalization, history of dialysis or type of donator. Also, there was no significant correlation between the vertebra densitometry and the overall results of densitometry with avascular necrosis on MRI. The only factor associated with avascular necrosis in this study, was osteoporosis in the hip densitometry.

Prevalence, incidence, and associated factors of avascular necrosis in Korean patients with systemic lupus erythematosus: a nationwide epidemiologic study.

Avascular necrosis (AVN) is one of the most frequent types of organ damage in systemic lupus erythematosus (SLE). However, little is currently known about the epidemiology of AVN in SLE patients. The aim of this study was to estimate the prevalence and incidence of AVN in Korean patients with SLE based on National Health Insurance (NHI) claims data and to determine the risk factors for AVN among SLE patients. This study was conducted using the 2006-2010 data of 25,358 SLE patients from the NHI program. AVN cases were defined as those with at least one diagnosis of AVN. The prevalence was calculated by dividing the number of AVN cases by the number of SLE cases in the same year. The annual incidence was calculated by dividing the number of incident AVN cases by the number of SLE-prevalent cases not previously diagnosed with AVN. Patients who developed AVN in 2008-2010 were compared with SLE patients who did not develop AVN to identify any risk factors. The prevalence of AVN among SLE patients (2006-2010) was 31.5-34.2 per 1,000 persons and was similar in all the years studied. The incidence per 1,000 persons of AVN among SLE patients was 8.6 [95 % confidence interval (95 % CI) 6.9-10.3] in 2008, 9.8 (95 % CI 8.0-11.6) in 2009, and 8.4 (95 % CI 6.8-10.0) in 2010. Regression analysis indicated that taking an oral corticosteroid [odds ratio (OR) 2.12, 95 % CI 1.39-3.23] or an intravenous corticosteroid (OR 1.5, 95 % CI 1.2-1.89) was significantly associated with AVN. In addition, AVN was associated with use of immunosuppressive agents (OR 2.12, 95 % CI 1.66-2.72), hydroxychloroquine (OR 1.4, 95 % CI 1.09-1.81), and lipid-lowering agents (OR 1.78, 95 % CI 1.24-2.57) among the prescribed medications, and with hypertension (OR 1.39, 95 % CI 1.08-1.79) among the comorbidities. The prevalence and incidence of AVN among SLE patients, which were 31.5-34.2 and 8.4-9.8 per 1,000 persons, respectively, may be representative of the entire population of symptomatic AVN patients with SLE in Korea. AVN is associated with the use of corticosteroids, immunosuppressants, hydroxychloroquine, lipid-lowering agents, and with hypertension. Studies of large, prospective cohorts are needed to confirm these results.

Avascular necrosis in sickle cell (homozygous S) patients: Predictive clinical and laboratory indices

Pathogenetic mechanism as well as laboratory and clinical correlates of osteonecrosis in sickle cell have not been fully investigated. The aim of this study is to investigate the predictive value of the steady state white cell and platelet count as well as the frequency of bone pain crisis per annum to detect sickle cell patients who will eventually develop avascular necrosis (AVN). A 5 year retrospective analysis of 122 homozygous S (HbSS) patients, aged 6-49 years (mean age 24.7 ± 7 years), out of which 16 patients (13.1%) had developed AVN within the years under review. The prevalence of AVN in sickle cell patients was determined to be 13.1 per 1000. The steady state white cell count, platelet count, frequency of bone pain crisis and hematocrit, was compared in patients that develop AVN and those who had not over the period. Only the steady state platelet count was found to differ significantly ( P = 0.011) between these two patient groups and to correlate positively (Pearson correlation coefficient = -0.251) with development of AVN. The hematocrit, white cell count, and frequency of bone pain crisis were found neither to differ significantly nor correlate with the development of AVN. In conclusion, patients with a raised steady state platelet count may have a higher tendency to develop AVN and may require closer orthopedic review and prophylactic intervention.

Decompression syndrome and diving behavior in Odontochelys, the first turtle

Odontochelys semitestacea, the oldest known turtle, from the Late Triassic of China, shows a pathology. Sharply defined, focal depressions were noted on the articular surfaces of both humeri, documenting avascular necrosis. Diving habits of Mesozoic marine reptiles have been characterized on the basis of this localized form of bone death attributed to decompression syndrome. Pursuit by a predator was likely the cause of dangerously rapid depth changes by swimming turtles. The prevalence of avascular necrosis decreased geometrically from the Cretaceous to the Pleistocene. This study suggests that the habit of repetitive diving in turtles was already present in the Late Triassic, but that protective physiological and behavioral adaptations had not yet evolved.

Slipped capital femoral epiphysis

Complication rates after the treatment of slipped capital femoral epiphysis (SCFE) were retrospectively evaluated to identify possible risk factors. Twenty-six patients with SCFE underwent reduction and fixation with a single screw or multiple wires. The prevalence of avascular necrosis (AVN) of the hip or chondrolysis was 14.8 and 3.6%, respectively. The degree of SCFE (P=0.050) and reduction before the seventh day after the slip (P=0.028) were associated with AVN. The risk factors for AVN were found to be a higher grade of SCFE correction and reduction between the second and the seventh day after SCFE.

Prevalence and Risk of Avascular Osteonecrosis in Inflammatory Bowel Disease

Purpose: Avascular necrosis (AVN) of bone is a dreaded complication of prolonged steroid use. Case series in patients with inflammatory bowel disease (IBD) have reported an association between steroids and AVN of the hip/neck of femur and other sites. However, the prevalence of AVN has not been studied in depth in a large IBD population. Given that IBD patients often develop steroid-dependent disease, we sought to investigate the prevalence of AVN in IBD and to determine whether risk is related to length of steroid exposure. Methods: Using a large administrative health claims database, we conducted a retrospective cohort analysis to determine the prevalence AVN in IBD and identify factors associated with AVN occurrence. ICD-9 codes were used to identify subjects with IBD and diagnosis of AVN. We excluded subjects who also had diagnoses of lupus and other disorders for which steroids are used frequently. Treatment with steroids was documented and categorized into four exposure groups based on duration of use. All subjects were followed forward in time until the occurrence of AVN, end of capture period (Dec 2006) or end of enrollment. The prevalence of AVN in IBD was compared to that in a non-IBD population (1:5 ratio). Logistic regression was used to calculate independent risk (expressed as odds ratio [OR]) for AVN stratified by steroid exposure. Results: 53,434 IBD subjects were included and mean follow-up time was 2.4 years. The overall prevalence of AVN was 0.3% in IBD and 0.2% in non-IBD subjects. The rates were similar for Crohn's disease (CD) and ulcerative colitis (UC) but the steroid exposure overall was greater in CD. The risk of AVN with any steroid exposure compared to none was greater in CD (OR=2.1, P=0.0019) than in UC (OR=1.1, P=0.74). In a multivariate analysis, risk of AVN increased with longer steroid exposure, after adjustment for age and gender (Table). Conclusion: Among IBD patients, risk of AVN increases significantly with greater duration of steroid use. The prevalence is higher in CD than in UC but this difference may be due to lower steroid exposure in UC. There does not appear to be an increased risk for AVN due to IBD alone.Table

Risk factors for avascular bone necrosis in patients with systemic lupus erythematosus

The objective was to investigate the predictive factors for avascular necrosis (AVN) of bone in patients with systemic lupus erythematosus (SLE). The records of 868 patients with SLE from four centers were reviewed retrospectively. Forty-nine patients with AVN were identified. A total of 154 patients with SLE who did not have clinically apparent AVN during the follow-up were evaluated as a control group. The demographic, clinical, laboratory and management characteristics of these two groups of patients were recorded according to predefined protocol and compared. The prevalence of AVN was detected 6% in our SLE population. The highest dose corticosteroid administered within 4months and total cumulative prednisolone dose were significantly higher in the SLE patients with AVN. The use of cytotoxic agent significantly higher proportion of patients with AVN. AVN tends to develop more frequently in male gender and younger patients. Oral ulcer, pleuritis, Raynaud's phenomenon, cutaneous vasculitis, lymphadenopathy, autoimmune thyroiditis, peripheral neuropathy and Sjögren's syndrome were higher incidence in SLE patients with AVN. The bilateral femoral heads were the commonest site of involvement of AVN in our patients with SLE.

Screw placement in slipped upper femoral epiphysis: is good the enemy of better?

Introduction and aims A single hip screw is the recommended method of fixation for slipped upper femoral epiphysis (SUFE). Current practice favours the placement of the screw in the centre of the femoral head on both anteroposterior and lateral planes to avoid the risks of chondrolysis and avascular necrosis (AVN). We investigated the correlation between different positions of the screw in the femoral head and the prevalence of AVN, chondrolysis, late slippage and the time to epiphyseal closure. Methods The clinical notes and radiographs of 38 consecutive patients (61 hips) who underwent single screw fixation for SUFE were evaluated retrospectively with a mean follow-up of 36 months. Two-way ANOVA and the post hoc test was performed to analyse the correlation between the different variables and the outcome at the 5% level of significance. Results There were 16 acute slips, 18 chronic slips and ten acute-on-chronic slips. Seventeen slips were treated prophylactically. Mild slip was encountered in 39 hips, moderate slip in four and severe slip in one. The central-central position was only achieved in 51% of cases. The most significant results of the study were as follows: (1) no significant difference between the time to epiphyseal closure and the position of the screw, and (2) no late slippage or chondrolysis was observed in our series. Conclusion Our results showed that the positioning of the screw other than in the centre of the femoral head has the ability to provide physeal stability and has no correlation with the timing to closure of the epiphysis and the risk of avascular necrosis or chondrolysis. We therefore recommend that other positions be considered if the "optimal central-central position" is not initially achieved - specifically for the treatment of mild slip - as the potential hazards from several attempts to achieve the optimum position outweigh the benefits.

外傷性股関節前方脱臼の３症例

Traumatic dislocations of the hip joint are high energy and uncommon injuries. Traumatic anterior dislocation accounts for about 10% of all hip dislocations and is classified into superior and inferior types. We experienced 3 cases of superior type anterior hip dislocation. The average age was 33 years and the follow-up period ranged from 3 to 12 months, averaging 7 months. Secondary osteoarthritis and avascular necrosis (AVN) of the femoral head are reported as complications of anterior hip dislocation. The prevalence of AVN may be higher when reduction is delayed for more than 24 hours. All our patients took early reduction, averaging 2.5 hours, post injury one open reduction and the others closed reduction. Good ROM was achieved and pain disappeared. No arthritis and AVN of the femoral head were seen. After reduction, all our cases were inhibited with weight bearing for more than 3 weeks. All achieved good clinical results, but further follow-up is required.

Is Hb A2 Elevated in Adults with Sickle-A-Thalassemi (βS/βS; -α/-α)

Thirteen patients with sickle cell anemia (SS) were found to have two a gene deletions with a presumptive genotype of βs/βs; -α/-α. Hematological data showed that this group of patients had elevated Hb A2 level. in order to determine whether the elevation of Hb A2 is typical of SS with a two α gene deletion or is due to undiagnosed S-β°-thalassemia with a two a gene deletion we looked for the presence or absence of β°-thalassemia by molecular techniques. The latter included reverse dot-blot hybridization to rule out a β-thalassemia mutation, digestion with Cvn endonuclease followed by Southern blotting and hybridization with a β genomic probe, and, in selected patients, determination of the synthetic α/β ratio. One of the 13 patients had S-β°-thalassemia with a G→A mutation at IVS-11-1 indicating that her genotype was βs/β° thalassemia; -α/-α. The remaining 12 patients were homozygous for the sickle gene, had relatively elevated Hb levels, increased Hb A2 values, and Hb F levels similar to those in patients with SS and four or three α genes. At the clinical level, the 12 patients with SS and a two α gene deletion had increased prevalence of avascular necrosis, retinopathy, and splenomegaly, but decreased prevalence of leg ulcers and cerebrovascular accidents. Together, the data indicate that SS with a two a gene deletion (βs/βs; -α/α) is a unique subset of patients with SS characterized by distinct hematological and clinical features.

SICKLE CELL DISEASE AND SILENT AVASCULAR NECROSIS OF THE HIP

We reviewed the prevalence of avascular necrosis (AVN) in a series of patients with sickle cell disease, using radiography and magnetic resonance imaging. We found AVN of at least one hip in 11 of 27 patients (41%). This is a significantly greater prevalence than reported. MRI was not as helpful in patients with sickle cell disease as it is in patients with AVN from other causes; it detected no more cases than radiography.

The prevalence of avascular necrosis in sickle cell anemia: correlation with alpha-thalassemia.

The purpose of the present study was to investigate the effect of alpha-thalassemia on the prevalence of avascular necrosis in 52 adult patients with sickle cell anemia. alpha-Globin genotypes were determined by restriction endonuclease mapping of genomic DNA extracted from peripheral blood leukocytes. Radiographs of humeral and femoral heads were interpreted by two radiologists who were not aware of the clinical picture and the genotype of the patients in the study. We present data showing that there is a significant positive correlation between alpha-gene deletion and the prevalence and extent of avascular necrosis in our patient population.

Avascular Necrosis of Bone After Renal Transplantation

Avascular necrosis (AN) of bone developed in 11 of 100 children who received renal transplants from 1964 to 1977. Bones involved were femoral heads, 14; femoral condyles, 12; tall, two; and carpal naviculars, two. Seven children with symptomatic AN of the femoral heads were treated with limited weight bearing; three subsequently required arthroplasty, and degenerative joint disease developed in one. The AN at other joints healed clinically but not roentgenographically. Although the prevalence of AN decreased after 1967 coincident with a decrease in prednisone dose, children with AN received the same cumulative prednisone dose as children in a control group. Serum phosphorus levels were different in the AN and control groups, but other indexes of hyperparathyroidism were similar. The relative contributions of prednisone therapy and hyperparathyroidism to the development of AN could not be delineated.